Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M149/00—Lubricating compositions characterised by the additive being a macromolecular compound containing nitrogen
  • C10M149/12—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • C10M149/14—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds a condensation reaction being involved
  • C10M149/22—Polyamines
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M171/00—Lubricating compositions characterised by purely physical criteria, e.g. containing as base-material, thickener or additive, ingredients which are characterised exclusively by their numerically specified physical properties, i.e. containing ingredients which are physically well-defined but for which the chemical nature is either unspecified or only very vaguely indicated
  • C10M171/06—Particles of special shape or size
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M175/00—Working-up used lubricants to recover useful products ; Cleaning
  • C10M175/0091—Treatment of oils in a continuous lubricating circuit (e.g. motor oil system)
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2215/00—Organic non-macromolecular compounds containing nitrogen as ingredients in lubricant compositions
  • C10M2215/02—Amines, e.g. polyalkylene polyamines; Quaternary amines
  • C10M2215/04—Amines, e.g. polyalkylene polyamines; Quaternary amines having amino groups bound to acyclic or cycloaliphatic carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2215/00—Organic non-macromolecular compounds containing nitrogen as ingredients in lubricant compositions
  • C10M2215/26—Amines
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2217/00—Organic macromolecular compounds containing nitrogen as ingredients in lubricant compositions
  • C10M2217/04—Macromolecular compounds from nitrogen-containing monomers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • C10M2217/046—Polyamines, i.e. macromoleculars obtained by condensation of more than eleven amine monomers
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2217/00—Organic macromolecular compounds containing nitrogen as ingredients in lubricant compositions
  • C10M2217/06—Macromolecular compounds obtained by functionalisation op polymers with a nitrogen containing compound
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/25—Internal-combustion engines
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/25—Internal-combustion engines
  • C10N2040/251—Alcohol fueled engines
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/25—Internal-combustion engines
  • C10N2040/255—Gasoline engines
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/25—Internal-combustion engines
  • C10N2040/255—Gasoline engines
  • C10N2040/28—Rotary engines

Definitions

• the present invention pertains to a method and apparatus for removing sludge and varnish precursors from a lubricating oil disposed within an internal combustion engine and for improving the oxidative stability of the lubricating oil. More particularly, the invention pertains to a method and apparatus for achieving this purpose by contacting the oil with an insoluble compound having a dispersant functional group and in some cases also an antioxidant functional group.
• the compound may be in the form of a porous slab, a thin film, or in the form of discrete particles which are within a circulating oil system but do not have a core substrate. These discrete particles may be "encaged", i.e. held inside of some large structural member by means of filter paper, wire mesh or by some other suitable means.
• polar hydrocarbon contaminants are formed due to incomplete combustion of the fuel.
• Typical contaminants include low molecular weight polar alkyl compounds such as alcohols, aldehydes, ketones, carboxylic acids, and the like.
• These contaminants are sludge and varnish precursors which pass into the lubricating oil with combustion blow-by gases where they contact water in the oil and agglomerate to form an emulsion which is commonly referred to as sludge. Sludge and varnish precursors can also arise from oil oxidation.
• the dispersant functional group is a crosslinked polyethylene amine which is in the form of discrete particles encaged within a conventional oil filter.
• the invention provides a method of reducing the presence of sludge or varnish precursors in a lubricating oil which comprises contacting a lubricating oil containing sludge or varnish precursors with an oil insoluble, oil wettable cross-linked amine comprising one or more compounds having a dispersant functional group and of an antioxidant functional group, which compound is capable of complexing with sludge or varnish precursors and which compound is in the form of a plurality of discrete solid particles which are not deposited with a substrate, wherein the cross-linked amine has ethylene amine functionality, and has been cross-linked with a component selected from metal alkoxides, silanes, silicates, epoxides, quinones, phenol-formaldehyde compounds and polyisobutylene succinic anhydride.
• the invention also provides a method for reducing the presence of sludge or varnish precursors in a lubricating oil by providing a plurality of oil insoluble, oil wettable, solid particles comprising one or more compounds having a dispersant functional group and in some cases an antioxidant functional group, which particles are capable of complexing with sludge or varnish precursors; and encaging said particles in the path of a lubricating oil circulating within an internal combustion engine without having incorporated said particles with a substrate, which encaging prevents the transmigration of said particles to said internal combustion engine by the lubricating oil.
• the invention further provides an article for use in the methods of the invention which comprises (a) a plurality of discrete solid particles of an oil insoluble, oil wettable, cross-linked amine compound as hereinbefore defined and (b) means for encaging said particles in the path of a lubricating oil circulating within an internal combustion engine without adhering said particles to a substrate, which encaging means prevents the transmigration of said particles to said internal combustion engine by the lubricating oil.
• the invention still further provides an article as hereinbefore defined which further comprises (a) a hollow, oil impermeable housing having oil ingress and oil egress means, and (b) at least one filtering media selected from the group consisting of chemically active filter media, physically active filter media and inactive filter media.
• dispersants are typically blended within a motor oil and comprise a solubilizing group such as polybutene and a functional group that complexes, reacts or interacts with sludge, sludge presursors and varnish precursors (hereinafter referred to as dispersant functional group).
• antioxidants are typically blended within a motor oil and may comprise a solubilizing group and an active antioxidant functional group.
• An antioxidant functional group is a chemical group that protects a lubricating oil from oxidation without the need for a solubilizing group, although one may be present.
• sludge and varnish precursors can be removed from a lubricating oil and antioxidation protection provided without the need for a solubilizing group by incorporating an antioxidant functional group and/or a dispersant functional group in the form of discrete particles positioned in the path of circulating engine oil.
• an antioxidant functional group and/or a dispersant functional group in the form of discrete particles positioned in the path of circulating engine oil.
• the compounds containing a dispersant functional group or antioxidant functional group useful within the context of the present invention are those which are oil insoluble but oil wettable.
• the oil insoluble, oil wettable compounds useful in the invention are crosslinked amines having ethylene amine functionality.
• polyethylene amines are those commercially available from the Virginia Chemical group of Hoechst Celanese Corporation as Corcat R grades P-12, P-18, P-150 and JP-600. These have number average molecular weights ranging from 100 to 60,000, preferably from 1,000 to 5,000 and more preferably from 1,000 to 3,000.
• Other amines include 2-methylpentamethylene diamine, diethylene triamine, triethylene tetraamine.
• the most preferred class of amines includes Polyamine H, a bottoms product formed in the manufacture of polyethylene amine which contains approximately 6-8 ethylene groups and is commercially available from Union Carbide.
• amines are preferably crosslinked by a crosslinking agent, for example those selected from the group consisting of metal alkoxides, silanes, silicates, quinones, and phenol-formaldehyde compounds.
• a crosslinking agent for example those selected from the group consisting of metal alkoxides, silanes, silicates, quinones, and phenol-formaldehyde compounds.
• the most preferred crosslinking agent is benzoquinone.
• the most preferred antioxidant functional group is benzoquinone.
• the amount of dispersant functional group containing compound used can vary broadly depending upon the amount of sludge or sludge and varnish precursors in the oil. However, although only an amount effective to reduce the sludge and varnish precursor content of the lubricating oil need be used, the amount will typically range from 0.1 to 10 wt.%, preferably from 0.2 to 2.0 wt.%, based on weight of the lubricating oil, provided the dispersant functional group particles are the only dispersant functional group in the system.
• the dispersant functional group containing compound is in the form of discrete particles which may have a particle size ranging from 0.001 mm to 50 mm, preferably from 0.01 mm to 10 mm and most preferably from 0.1 mm to 5 mm.
• the discrete particles are positioned in the path of a lubricating oil circulating within an internal combustion engine without adhering or having deposited the particles on a substrate. This is preferably done by encaging them within a filter media to prevent the transmigration of the particles to said internal combustion engine by the lubricating oil.
• One method of encaging such particles is to dispose them with or without a small amount of binder polymer between sheets of conventional paper or filter media in a typical oil filter.
• Another method may be by enclosing the particles within a netting or screen material. Any method of encaging is useful provided the particles remain discrete, to expose essentially their entire surface area to circulating oil, while preventing the migration of the particles to the combustion chamber of the engine.
• the particles can be located within or external to the lubrication system of the internal combustion engine. Preferably, the particles will be located within the lubrication system such as on the engine block or near the sump.
• Sludge and sludge precursors are present in essentially any lubricating oil used in the lubrication system of essentially any internal combustion engine, including automobile and truck engines, two-cycle engines, aviation piston engines, marine and railroad engines, gas-fired engines, alcohol (e.g. methanol) powered engines, stationary powered engines, and turbines.
• the sludge precursors are commonly produced as the result of reaction between combustion by-products, fuel and lubricant.
• Another source of sludge precursors is oil or additive oxidation.
• the lubricating oil will normally comprise a major amount of lubricating oil basestock or lubricating base oil, and a minor amount of one or more additives.
• the lubricating oil basestock can be derived from natural lubricating oils, synthetic lubricating oils, or mixtures thereof.
• the lubricating oil basestock will have a viscosity in the range of 5 to 10,000 cSt at 40° C., although typical applications will require an oil having a viscosity ranging from 10 to 1,000 cSt at 40° C.
• Natural lubricating oils include animal oils, vegetable oils (e.g. castor oil and lard oil), petroleum oils, mineral oils, and oils derived from coal or shale.
• Synthetic oils include hydrocarbon oils and halosubstituted hydrocarbon oils such as polymerized and interpolymerized olefine (e.g. polybutylenes, polypropylenes, propylene-isobutylene copolymers, chlorinated polybutylenes, poly(1-hexenes), poly(1-octenes), poly(1-decenes), etc., and mixtures thereof); alkylbenzenes (e.g.
• Synthetic lubricating oils also include alkylene oxide polymers, interpolymers, copolymers and derivatives thereof wherein the terminal hydroxyl groups have been modified by esterification, etherification, etc.
• This class of synthetic oils is exemplified by polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide; the alkyl and aryl ethers of these polyoxyalkylene polymers (e.g. methyl-polyisopropylene glycol ether having an average molecular weight of 1000, diphenyl ether of polyethylene glycol having a molecular weight of 500-1000, diethyl ether of polypropylene glycol having a molecular weight of 1000-1500); and mono- and polycarboxylic esters thereof (e.g., the acetic acid esters, mixed C 3 -C 8 fatty acid esters, and C 13 oxo acid diester of tetraethylene glycol).
• polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide
• the alkyl and aryl ethers of these polyoxyalkylene polymers e.g. methyl-polyisopropylene glycol ether having
• Another suitable class of synthetic lubricating oils comprises the esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebasic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkylmalonic acids, alkenyl malonic acids, etc.) with a variety of alcohols (e.g. butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol, etc.).
• dicarboxylic acids e.g., phthalic acid, succinic acid, alkyl succinic acids and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebasic acid, fumaric acid, adipic acid,
• esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid, and the like.
• Esters useful as synthetic oils also include those made from C 5 to C 12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, and the like.
• Synthetic hydrocarbon oils are also obtained from hydrogenated oligomers of normal olefins.
• Silicon-based oils (such as the polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils and silicate oils) comprise another useful class of synthetic lubricating oils.
• oils include tetraethyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl) silicate, tetra-(4-methyl-2-ethylhexyl) silicate, tetra(p-tert-butylphenyl) silicate, hexa-(4-methyl-2-pentoxy)-disiloxane, poly(methyl)-siloxanes and poly(methylphenyl) siloxanes, and the like.
• Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of decylphosphonic acid), polymeric tetrahydrofurans, polyalphaolefins, and the like.
• liquid esters of phosphorus-containing acids e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of decylphosphonic acid
• polymeric tetrahydrofurans e.g., polyalphaolefins, and the like.
• the lubricating oil may be derived from unrefined, refined, rerefined oils, or mixtures thereof.
• Unrefined oils are obtained directly from a natural source or synthetic source (e.g., coal, shale, or tar sands bitumen) without further purification or treatment.
• Examples of unrefined oils include a shale oil obtained directly from a retorting operation, a petroleum oil obtained directly from distillation, or an ester oil obtained directly from an esterification process, each of which is then used without further treatment.
• Refined oils are similar to the unrefined oils except that refined oils have been treated in one or more purification steps to improve one or more properties.
• Suitable purification techniques include distillation, hydrotreating, dewaxing, solvent extraction, acid or base extraction, filtration, and percolation, all of which are known to those skilled in the art.
• Rerefined oils are obtained by treating refined oils in processes similar to those used to obtain the refined oils. These rerefined oils are also known as reclaimed or reprocessed oils and often are additionally processed by techniques for removal of spent additives and oil breakdown products.
• the lubricating base oil may contain one or more additives to form a fully formulated lubricating oil.
• Such lubricating oil additives include antiwear agents, antioxidants, corrosion inhibitors, detergents, pour point depressants, extreme pressure additives, viscosity index improvers and friction modifiers.
• Typical additives are shown in U.S. Pat. No. 4,105,571. Normally, there is from 1 to 20 wt.% of these additives in a fully formulated engine lubricating oil. Dispersants and antioxidants may also be included as additives in the oil if desired, although this invention partially or completely negates their need. However, the precise additives used and their relative amounts will depend upon the particular application of the oil.
• This invention can also be combined with the removal of sludge or varnish precursors from a lubricating oil as described in U.S. Patent 5,042,617 and discussed earlier herein.
• This method provides for the incorporation of a dispersant functional group immobilized by intimate association with a substrate.
• any of the foregoing embodiments of the invention can be combined with a system for reducing piston deposits in an internal combustion engine which result from neutralizing acids present in the lubricating oil of the engine.
• the system provides a lubricating oil that circulates through the lubrication system of the engine, and a soluble weak base capable of neutralizing acids present in the oil to form soluble neutral salts containing the weak base and the acids.
• the weak bases can be basic organophosphorus compounds, basic organonitrogen compounds, or mixtures thereof, with basic organonitrogen compounds being preferred. Families of basic organophosphorus and organonitrogen compounds include aromatic compounds, aliphatic compounds, cycloaliphatic compounds, or mixtures thereof.
• Examples of basic organonitrogen compounds include, but are not limited to, pyridines; anilines; piperazines; morpholines; alkyl, dialkyl, and trialkyl amines; alkyl polyamines; and alkyl and aryl guanidines.
• Alkyl, dialkyl, and trialkyl phosphines are examples of basic organophosphorus compounds.
• Examples of particularly effective weak bases are the dialkyl amines (R 2 HN), trialkyl amines (R 3 N), dialkyl phosphines (R 2 HP), and trialkyl phosphines (R 3 P), where R is an alkyl group, H is hydrogen, N is nitrogen, and P is phosphorus.
• the alkyl group should be substantially saturated and from 1 to 22 carbons in length.
• the total number of carbon atoms in the alkyl groups should be from 12 to 66.
• the individual alkyl group will be from 6 to 18, more preferably from 10 to 18, carbon atoms in length.
• Trialkyl amines and trialkyl phosphines are preferred over the dialkyl amines and dialkyl phosphines.
• dialkyl and trialkyl amines examples include tributyl amine (or phosphine), dihexyl amine (or phosphine), decylethyl amine (or phosphine), trihexyl amine (or phosphine), trioctyl amine (or phosphine), trioctyldecyl amine (or phosphine), tridecyl amine (or phosphine), dioctyl amine (or phosphine), trieicosyl amine (or phosphine), tridocosyl amine (or phosphine), or mixtures thereof.
• tributyl amine or phosphine
• dihexyl amine or phosphine
• decylethyl amine or phosphine
• trihexyl amine or phosphine
• trioctyl amine or phosphine
• Preferred trialkyl amines are trihexyl amine, trioctadecyl amine, or mixtures thereof, with trioctadecyl amine being particularly preferred.
• Preferred trialkyl phosphines are trihexyl phosphine, trioctyldecyl phosphine, or mixtures thereof, with trioctadecyl phosphine being particularly preferred.
• Still another example of a suitable weak base is a polyethyleneamine imide or amide of polybutenylsuccinic anhydride with more than 40 carbons in the polybutenyl group (see for example U.S. patent 5,164,101 which is incorporated herein by reference).
• the weak base must be strong enough to neutralize the combustion acids (i.e., form a salt). Suitable weak bases will typically have a PKa from about 4 to about 12. However, even strong organic bases (such as organoguanidines) can be utilized as the weak base if the strong base is an appropriate oxide or hydroxide and is capable or releasing the weak base from the weak base/combustion acid salt.
• strong organic bases such as organoguanidines
• the molecular weight of the weak base should be such that the protonated nitrogen compound retains its oil solubility.
• the weak base should have sufficient solubility so that the salt formed remains soluble in the oil and does not precipitate. Adding alkyl groups to the weak base is the preferred method to ensure its solubility.
• the amount of weak base in the lubricating oil for contact at the piston ring zone will vary depending upon the amount of combustion acids present, the degree of neutralization desired, and the specific applications of the oil. In general, the amount need only be that which is effective or sufficient to neutralize at least a portion of the combustion acids present at the piston ring zone. Typically, the amount will range from 0.01 to about 3 wt. % or more, preferably from 0.1 to 1.0 wt.
• the neutral salts are passed or circulated from the piston ring zone with the lubricating oil and contacted with a heterogeneous strong base.
• strong base is meant a base that will displace the weak base from the neutral salts and return the weak base to the oil for recirculation to the piston ring zone where the weak base is reused to neutralize combustion acids.
• strong bases examples include, but are not limited to, barium oxide (BaO), magnesium carbonate (MgCO 3 ), magnesium hydroxide (Mg(OH) 2 ), magnesium oxide (MgO), sodium aluminate (NaAlO 2 ), sodium carbonate (Na 2 CO 3 ), sodium hydroxide (NaOH), zinc oxide (ZnO), or their mixtures, with MgO being particularly preferred.
• heterogeneous strong base is meant that the strong base is in a separate phase (or substantially in a separate phase) from the lubricating oil, i.e., the strong base is insoluble or substantially insoluble in the oil.
• the strong base may be incorporated (e.g.
• the substrate can be located on the engine block or near the sump.
• the substrate will be part of the filter system for filtering oil, although it could be separate therefrom.
• Suitable substrates include, but are not limited to, alumina, activated clay, cellulose, cement binder, silica alumina, and activated carbon.
• the alumina, cement binder, and activated carbon are preferred, with cement binder being particularly preferred.
• the substrate may (but need not) be inert.
• the amount of strong base required will vary with the amount of weak base in the oil and the amount of combustion acids formed during engine operation.
• the strong base since the strong base is not being continuously regenerated for reuse as is the weak base (i.e., the alkyl amine), the amount of strong base must be at least equal to (and preferably be a multiple of) the equivalent weight of the weak base in the oil. Therefore, the amount of strong base should be from 1 to about 15 times, preferably from 1 to about 5 times, the equivalent weight of the weak base in the oil.
• the strong base/strong combustion acid salts thus formed will be immobilized as heterogeneous deposits with the strong base or with the strong base on a substrate if one is used. Thus, deposits which would normally be formed in the piston ring zone are not formed until the soluble salts contact the strong base.
• the strong base will be located such that it can be easily removed from the lubrication system (e.g., included as part of the oil filter system).
• the presence of a strong base also serves to protect the crosslinked dispersant functional group containing composition of this invention from the acids generated by an internal combustion engine.
• the crosslinked dispersant functional group containing compositions used by this invention are generally weakly basic. Thus when such engine acids are carried to the filter, the crosslinked dispersant functional group containing composition would be neutralized and lose its functionality.
• the strong base would neutralize the engine acids before they could neutralize the dispersant functional group and hence protect them.
• any of the foregoing embodiments of this invention can be combined with the removal of carcinogenic components from a lubricating oil.
• polynuclear aromatic hydrocarbons especially PNA's with at least three aromatic rings
• PNA's with at least three aromatic rings that are usually present in used lubricating oil can be substantially removed (i.e., reduced by from about 60 to about 90% or more) by passing the oil through a sorbent located within the lubrication system through which the oil must circulate after being used to lubricate the engine.
• the sorbent may be immobilized with the substrate described above or immobilized separate therefrom.
• the substrate and sorbent will be part of the engine filter system for filtering oil.
• the sorbent can be conveniently located on the engine block or near the sump, preferably downstream of the oil as it circulates through the engine; i.e., after the oil has been heated. Most preferably, the sorbent is downstream of the substrate when a substrate is present.
• Suitable sorbents include activated carbon, attapulgus clay, silica gel, molecular sieves, dolomite clay, alumina, zeolite, or mixtures thereof.
• Activated carbon is preferred because it is at least partially selective to the removal of polynuclear aromatics containing more than 3 (and preferably 4, 5 and 6) aromatic rings; the PNA's removed are tightly bound to the carbon and will not be leached-out to become free PNA's after disposal; the PNA's removed will not be redissolved in the used lubricating oil; and heavy metals such as lead and chromium will be removed as well.
• sorbent such as a circular mass of sorbent supported on wire gauze.
• an oil filter could comprise the sorbent capable of combining with polynuclear aromatic hydrocarbons held in pockets of filter paper.
• the sorbent could be in the form of a solid cylinder as in US-A-5,209,839. Any of the foregoing embodiments of this invention can also be combined with a sorbent, such as those described above that is mixed, coated, or impregnated with additives normally present in engine lubricating oils.
• additives such as the lubricating oil additives described above, are slowly released into the lubricating oil to replenish the additives as they are depleted during operation of the engine.
• the ease with which the additives are released into the oil depends upon the nature of the additive and the sorbent. Preferably, however, the additives will be totally released within 150 hours of engine operation.
• the sorbent may contain from about 50 to about 100 wt.% of the additive, based on the weight of activated carbon, which generally corresponds to 0.5 to 1.0 wt.% of the additive in the lubricating oil.
• This invention may also be combined with any method for removing hydrope oxides from a lubricating oil by contacting the oil with a heterogeneous hydroperoxide decomposer for a period of time sufficient to cause a reduction in the amount of hydroperoxides present in the oil.
• Hydroperoxides are produced when hydrocarbons in the lubricating oil contact the peroxides formed during the fuel combustion process.
• hydroperoxides will be present in essentially any lubricating oil used in the lubrication system of essentially any internal combustion engine, including those mentioned above.
• U.S. patents 4,997,546 and 5,112,482 disclose the use of compounds, especially certain molybdenum compounds which decompose hydroperoxides.
• hydroperoxides can be effectively removed from used lubricating oil provided the oil also contains a metal thiophosphate.
• the NaOH should be immobilized in some manner when contacting the oil, for example in crystalline form or incorporated on a substrate to avoid solids passing into the oil.
• hydroperoxides are removed from lubricating oil circulating within the lubrication system of an internal combustion engine by contacting the oil with crystalline NaOH immobilized within the lubrication system.
• the precise amount of hydroperoxide decomposer used can vary broadly, depending upon the amount of hydroperoxide present in the lubricating oil. However, although only an amount effective or sufficient to reduce the hydroperoxide content of the lubricating oil need be used, the amount of decomposer will typically range from 0.01 to 2.0 wt.%, although greater amounts could be used. Preferably, from 0.05 to 1.0 wt.% (based on weight of the lubricating oil) of the decomposer will be used.
• the hydroperoxide decomposer should be immobilized in some manner when contacting the oil. For example, it could be immobilized on a substrate. However, a substrate would not be required if the decomposer were in crystalline form.
• the substrate may (or may not) be within the lubrication system of an engine. Preferably, however, the substrate will be located within the lubrication system, for example on the engine block or near the sump. More preferably, the substrate will be part of the filter system for filtering the engine's lubricating oil, although it could be separate therefrom.
• Suitable substrates include, but are not limited to, alumina, activated clay, cellulose, cement binder, silica-alumina, and activated carbon. Alumina, cement binder, and activated carbon are preferred substrates, with activated carbon being particularly preferred.
• the substrate may (but need not) be inert and can be formed into various shapes such as pellets or spheres.
• the decomposer may be incorporated on or with the substrate by methods known to those skilled in the art.
• the decomposer can be deposited by using the following technique.
• the decomposer is dissolved in a volatile solvent.
• the carbon is then saturated with the decomposer containing solution and the solvent evaporated, leaving the decomposer on the carbon substrate.
• the required metal thiophosphates used preferably comprises a metal selected from the group consisting of Group IB, IIB, VIB, VIII of the Periodic Table, and mixtures thereof.
• a metal dithiophosphate is a preferred metal thiophosphate, with a metal dialkyldithiophosphate being particularly preferred. Copper, nickel, and zinc are particularly preferred metals, with zinc being most preferred.
• the alkyl groups preferably comprise from 3 to 10 carbon atoms. Particularly preferred metal thiophosphates are zinc dialkyl-dithiophosphates.
• the amount of metal thiophosphate used in this invention can range broadly.
• the concentration of the metal thiophosphate will range from 0.1 to 2 wt.%, preferably from 0.3 to 1 wt.%, of the lubricating oil.
• NaOH and metal thiophosphates are commercially available from a number of vendors. As such, their methods of manufacture are well known to those skilled in the art.
• a typical oil filter comprises a canister containing a chemically active filter media, a physically active filter media, an inactive filter media or combinations thereof.
• the invention uses a two stage oil filter containing, in series, a first filter media having a chemically active filter media, a physically active filter media, or mixtures thereof and a second filter media having an inactive filter media can effectively rejuvenate used lubricating oils.
• the chemically or physically active filter media will be within a canister that is separate from a container having both active and inactive filter media. This filter system is more fully described in U.S. patent 5,069,799.
• Another useful filtering system uses a hollow solid composite composed of a thermoplastic binder and an active filter media that contains a chemically active or physically active filter media or both.
• chemically active filter media is meant a filter media that chemically interacts with the used lubricating oil (e.g., by chemical adsorption, acid/base neutralization).
• physically active filter media is meant a filter media that interacts with the lubricating oil by other than chemical interaction (e.g., by physical adsorption).
• the chemically active filter media will be or will contain a chemically active ingredient or ingredients, which may be supported on a substrate or unsupported. If supported, suitable substrates include those listed above.
• the substrate may but need not be inert.
• a chemically active filter media is a filter media that is or contains an oil insoluble, or substantially oil insoluble, strong base.
• active filter media is meant a filter media that is inert and does not interact with the lubricating oil except to remove particulates from the oil.
• the physically active filter media includes the same substrates suitable for use with the chemically active filter media as well as other substrates such as attapulgus clay, dolomite clay, and molecular sieves.
• An example of a physically active filter media is a media such as activated carbon that can remove polynuclear aromatics (PNA) from used lubricating oil, especially PNA's with at least three aromatic rings.
• PNA polynuclear aromatics
• a physically active filter media is also disclosed in U.S. patent 4,977,871 wherein the filter media is mixed, coated, or impregnated with one or more additives normally present in lubricating oils. These additives are oil soluble such that they will be slowly released into the oil to replenish the additives in the oil as they are depleted during its use of the oil.
• Suitable inactive filter media may be found in today's conventional engine oil filters and include porous paper (e.g. pleated paper), glass fibers, spun polymer filament, and the like. The inactive filter media serves to retain and remove solid particles from the oil. The precise amount of active filter media used will vary with the particular function to be performed.
• lubricating oil is defined to include industrial oils, hydraulic oils and fluids, automatic transmission oil, two cycle oils, gear oils, power transmission fluids, and heat transfer oils that contains polar hydrocarbon sludge or varnish precursors from which sludge is formed.
• TGA thermal gravimetric analysis
• test sample of known weight is placed in a DSC 30 Cell (Mettler TA 3000) and continuously heated with an inert reference at a programmed rate under an oxidizing air environment. If the test sample undergoes an exothermic or endothermic reaction or a phase change, the event and magnitude of the heat effects relative to the inert reference are monitored and recorded. More specifically, the temperature at which an exothermic reaction begins due to oxidation by atmospheric oxygen is considered as a measure of the oxidative stability of the test sample. The higher the DSC Break Temperature, the more oxidatively stable the test sample.
• the oxidation onset temperature is the temperature at which the baseline (on the exothermal heat flow versus temperature plot) intersects with a line tangent to the curve at a point one heat energy threshold above the baseline. At times it is necessary to visually examine the plot to identify the true heat energy threshold for the start of oxidation.
• a test oil is formed for the evaluation of filter attractants by running a fully formulated non-dispersant passenger car lubricant for 4828 km (3000 miles) is a Ford Taurus for 4828 km (3,000 miles)of commuter operation.
• the test oil is circulated through a filter assembly in a laboratory rig and evaluated for the formation of sludge. In some cases the filter assembly contains a filter attractant and in some cases it does not.
• two 10 gram samples of the oil are tested. The first sample is centrifuged prior to a test run at 210°C for 4 hours. The second sample is preheated to 138°C for 16 hours and then the test is run at 210°C for 4 hours.
• centrifugation The purpose of centrifugation is to remove separated sludge but to leave sludge precursors.
• the sludge precursors form additional sludge during the SIB test.
• the supernatant after centrifugation is subjected to heat cycling from about 150°C to room temperature over a period of 4 hours at a frequency of about 2 cycles per minute.
• a gas containing a mixture of about 0.7 volume percent of SO 2 , 1.4 volume % NO and the balance air is bubbled through the test samples.
• water vapor is bubbled through the test samples.
• the liquid is centrifuged in weighed centrifuge tubes and the amount of sludge separated from the supernatant is determined and reported as milligrams of sludge.
• the polymers are evaluated for dispersant filter performance in a lab filtration rig. Three tests are used for measuring performance, Sludge Inhibition Bench (SIB) for measuring sludge performance, Thermal Gravimetric Analysis (TGA) for measuring soot/ash removal and Differential Scanning Calorimetry (DSC) for measuring antioxidant performance.
• SIB Sludge Inhibition Bench
• TGA Thermal Gravimetric Analysis
• DSC Differential Scanning Calorimetry
• the test consists of circulating 100 ml of a non-dispersant but otherwise fully formulated lubricant which has been used for 4828 km (3000 miles) in a Ford Taurus test car through a filter containing 0.5 grams of the compound under test for 8 hours.
• the resulting oils are evaluated in a dispersant SIB bench test and in DSC (oxidation stability).
• the oils are also evaluated for Soot/Ash by TGA.
• the SIB data are obtained for the samples both when not preheated, and also where samples are preheated overnight. The following results are observed and compared to other filter attractants.
• Polymer E Benzoguinone with DETA (diethylene triamine)
• Polymer F Benzoguinone with TETA (triethvlene tetramine) amine.
• Polymer G is evaluated for dispersant filter performance in the lab filtration rig.
• the test used for measuring performance was FT-IR, Fourier Transform Infrared spectroscopy.
• a fresh oil fully formulated except that it did not contain dispersant is compared by FT-IR with the same oil after 4828 km (3,000 miles) service in a Ford Taurus in commuter use.
• the increase in the integrated area of absorbance in the OH stretching region, 3700-3100 cm-1, 34.09 units, is used as a measure of oil oxidation and sludge formation during the 4828 km (3,000 miles) of commuter service. 100 grs. of the 4828 km (3,000 mile) used oil is circulated for 8 hours through a filter containing 0.5 grs. of polymer G.
• test oil is compared to the fresh oil.
• the integrated area of absorbance, 8 hour test oil vs. fresh oil is 10.95 units representing a 68% reduction in oxidation products and sludge in the used oil.
• the 68% reduction in oxidation products and sludge measured by infrared is similar to the 59% reduction in sludge measured by the SIB test for a repeat preparation of Polymer G designated Polymer H.

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• Organic Chemistry (AREA)
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• Combustion & Propulsion (AREA)
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• 1994
  • 1994-04-19 JP JP6522526A patent/JPH08508773A/ja active Pending
  • 1994-04-19 DE DE69431560T patent/DE69431560T2/de not_active Expired - Lifetime
  • 1994-04-19 WO PCT/US1994/004262 patent/WO1994024237A1/en active IP Right Grant
  • 1994-04-19 EP EP94914211A patent/EP0703959B1/en not_active Expired - Lifetime
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