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
  • C10M159/00—Lubricating compositions characterised by the additive being of unknown or incompletely defined constitution
  • C10M159/12—Reaction products
  • C10M159/18—Complexes with metals
• • 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
  • C10M163/00—Lubricating compositions characterised by the additive being a mixture of a compound of unknown or incompletely defined constitution and a non-macromolecular compound, each of these compounds being essential
• • 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
  • C10M2219/00—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2219/06—Thio-acids; Thiocyanates; Derivatives thereof
  • C10M2219/062—Thio-acids; Thiocyanates; Derivatives thereof having carbon-to-sulfur double bonds
  • C10M2219/066—Thiocarbamic type compounds
  • C10M2219/068—Thiocarbamate metal salts
• • 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
  • C10M2223/00—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions
  • C10M2223/02—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions having no phosphorus-to-carbon bonds
  • C10M2223/04—Phosphate esters
  • C10M2223/045—Metal containing thio derivatives
• • 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
  • C10M2227/00—Organic non-macromolecular compounds containing atoms of elements not provided for in groups C10M2203/00, C10M2207/00, C10M2211/00, C10M2215/00, C10M2219/00 or C10M2223/00 as ingredients in lubricant compositions
  • C10M2227/09—Complexes with metals
• • 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
  • C10N2010/00—Metal present as such or in compounds
  • C10N2010/04—Groups 2 or 12
• • 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
  • C10N2010/00—Metal present as such or in compounds
  • C10N2010/12—Groups 6 or 16
• • 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
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/06—Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure

Definitions

• This invention relates to methods of lubricating surfaces, in particular, to methods of lubricating surfaces in internal combustion engines.
• a method of lubricating an aluminum alloy surface which comprises supplying to said surface a lubricating oil composition comprising an oil of lubricating viscosity, preferably in a major amount, and an oil-soluble trinuclear organo-molybdenum compound.
• the trinuclear organo-molybdenum additive will substantially reduce friction and surface wear on the aluminum containing alloy surfaces to an extent not observed with dinuclear-organo-molybdenum compounds.
• the aluminum alloy suitably comprises an aluminum-silicon alloy, which may additionally contain a proportion of copper and/or magnesium.
• the aluminum alloy has a hardness of 100-150 Hv, preferably 110-130 Hv and more preferably of about 120 Hv.
• the aluminum alloy has a density of 2.0-3.0 gcm -3 , preferably, 2.4-2.8 gcm -3 , and more preferably, about 2.6 gcm -3 .
• the trinuclear organo-molybdenum additive is used so as to provide 25 to 1000 ppm (parts per million, by weight), preferably 200 to 750 ppm, more preferably 400 to 600 ppm, and advatantageously 500 ppm of elemental molybdenum in the lubricating oil compositions (as determined by ASTM D5185).
• the lubricating oil composition of the first aspect of the invention may further comprise an oil soluble, zinc dihydrocarbyl dithiophosphate (ZDDP) produced from a primary alcohol, herein after referred to as primary ZDDP.
• ZDDP zinc dihydrocarbyl dithiophosphate
• primary ZDDP comprises at least 50%, preferably at least 75%, more preferably at least 90%, and advantageously comprises substantially 100% ZDDP produced from primary.
• the lubricating oil composition suitably comprises 0.2 to 1.0 mass %, preferably 0.4 to 0.8 mass %, and more preferably 0.6 ro 0.75 mass % primary ZDDP.
• the method according the first aspect of the invention suitably involves provision of lubrication between an aluminum alloy surface and a non-aluminum alloy surface, such as a ferrous surface, for example.
• a second aspect of this invention is an internal combustion engine having one or more component parts made from an aluminum alloy, and contained in a reservoir in the engine, a lubricating oil composition for lubricating said parts comprising an oil of lubricating viscosity, preferably in a major amount, and an oil-soluble, trinuclear organo-molybdenum compound.
• the reservoir in the engine may be a crankcase sump in four-stroke engines, from where it is distributed around the engine for lubrication.
• the invention is applicable to two-stroke and four-stroke spark-ignited and compression-ignited engines.
• a third aspect of the invention relates to the use of a lubricating oil composition comprising an oil of lubricating viscosity and an oil-soluble, trinuclear organo-molybdenum compound to lubricate an aluminum alloy surface.
• a fourth aspect of the invention provides the use of an oil-soluble, trinuclear organo-molybdenum compound in a lubricating oil composition to reduce the friction between surfaces, one of which comprising an aluminum alloy.
• a method of providing lubrication between two ferrous surfaces one of the ferrous surfaces comprising a chromium containing iron alloy conforming to British Standard BS EN31 and the other ferrous surfaces comprises a cast iron alloy conforming to British Standard BS EN1452, which method comprises supplying to said surface a lubricating oil composition comprising an oil of lubricating viscosity, preferably in a major amount, and an oil-soluble trinuclear organo-molybdenum compound.
• the trinuclear organo-molybdenum additive will substantially reduce friction and surface wear on the ferrous surfaces to an extent not observed with dinuclear-organo-molybdenum compounds.
• the trinuclear organo-molybdenum additive is used so as to provide 25 to 1000 ppm (parts per million, by weight), preferably 200 to 750 ppm, more preferably 400 to 600 ppm, and advatantageously 500 ppm of elemental molybdenum in the lubricating oil compositions (as determined by ASTM D5185).
• the lubricating oil composition of the fifth aspect of the invention may further comprise an oil soluble, zinc dihydrocarbyl dithiophosphate (ZDDP) made from secondary alcohol, hereinafter referred to as secondary ZDDP.
• ZDDP zinc dihydrocarbyl dithiophosphate
• the secondary ZDDP comprises at least 55%, preferably at least 79% and more preferably at least 85%, and may comprise subatantially 100% ZDDP made from secondary alcohol.
• the lubricating oil composition suitably comprises 0.2 to 1.0 mass %, preferably 0.4 to 0.8 mass %, and more preferably 0.6 to 0.75 mass % secondary ZDDP.
• a sixth aspect of this invention is an internal combustion engine having a component part made from a chromium containing ferrous alloy conforming with British Standard BS EN31 adjacent a component part made from an iron alloy conforming with British Standard BS EN1452, both compmeat parts being contained in a reservoir in the engine, a lubricating oil composition for lubricating said parts comprising an oil of lubricating viscosity, preferably in a major amount, and an oil-soluble, trinuclear organo-molybdenum compound.
• the reservoir in the engine maybe a crankcase sump in four-stroke engines, from where it is distributed around the engine for lubrication,
• the invention is applicable to two-stroke and four-stroke spark-ignited and compression-ignited engines.
• a seventh aspect of the invention relates to the use of a lubricating oil composition
• a lubricating oil composition comprising an oil of lubricating viscosity an oil-soluble, trinuclear organo-molybdenum compound to provide lubrication between a chromium containing ferrous alloy surface conforming with British Standard BS EN31 and an iron alloy surface conforming with British Standard BS EN1452.
• An eighth aspect of the invention provides the use of an oil-soluble, trinuclear organo-molybdenum compound in a lubricating oil composition to reduce the friction between a chromium containing ferrous alloy surface conforming with British Standard BS EN31 and an iron alloy surface conforming with British Standard BS EN1452.
• the methods of any aspect of this invention are especially applicable to the lubrication of spark-ignited or compression-ignited two-stroke or four-stroke internal combustion engines which have parts or components made from the specified materials.
• Such components include the cam shaft, especially the cam lobes; pistons, especially the piston skirt; cylinder liners; and valves.
• suitable oil-soluble, trinuclear organo-molybdenum compounds there may be mentioned dithiocarbamates, dithiophosphates, dithiophosphinates, xanthates, thioxanthates and sulfides of molybdenum and mixtures thereof.
• the molybdenum compounds may be acidic molybdenum compounds. These compounds will react with a basic nitrogen compound as measured by ASTM test D-664 or D-2896 titration procedure and are typically hexavalent. Included are molybdic acid, ammonium molybdate, sodium molybdate, potassium molybdate, and other alkaline metal molybdates and other molybdenum salts, e.g., molybdenum trioxide or similar acidic molybdenum compounds.
• a group of trinuclear organo-molybdenum compounds useful in the lubricating compositions of this invention are those of the formula Mo 3 S k L n Q z and mixtures thereof wherein L represents independently selected ligands having organo groups with a sufficient number of carbon atoms to render the compound soluble or dispersible in the oil, n is from 1 to 4, k varies from 4 through 7, Q is selected from the group of neutral electron donating compounds such as water, amines, alcohols, phosphines, and ethers, and z ranges from 0 to 5 and includes non-stoichiometric values.
• n 3 or 1
• appropriately charged ionic species is required to confer electrical neutrality to the trinuclear molybdenum compound.
• the ionic species may be of any valence, for example, monovalent or divalent. Further the ionic species may be negatively charged, i,e. an anionic species, or may be positively charged, i . e . a cationic species or a combination of an anion and a cation. Such terms are known to a skilled person in the art
• the ionic species may be present in the compound through covalent bonding, i.e.
• anionic species include disulfide, hydroxide, an alkoxide, an amide and a thiocyanste or derivate thereof; preferably the anionic species is disulfide ion.
• cationic species include an ammonium ion and a metal ion, such as an alkali metal, alkaline earth metal or transition metal, ion, preferably an ammonium ion, such as [NR 4 ] + where R is independently H or alkyl group, more preferably R is H, i.e. [NH 4 ] + . At least 21 total carbon atoms should be present among all the ligands' organo groups, such as at least 25, at least 30, or at least 35 carbon atoms.
• the ligands are independently selected from the group of: and mid mixtures thereof, wherein X, X 1 , X 2 , and Y are independently selected from the group of oxygen and sulfur, and wherein R 1 , R 2 , and R are independently selected from hydrogen and organo groups that may be the same or different
• the organo groups are hydrocarbyl groups such as alkyl (e,g., in which the carbon atom attached to the remainder of the ligand is primary or secondary), aryl, substituted aryl and ether groups. More preferably, each ligand has the same hydrocarbyl group.
• hydrocarbyl denotes a substituent having carbon atoms directly attached to the remainder of the ligand and is predominantly hydrocarbyl in character within the context of this invention.
• substituents include the following:
• the organo groups of the ligands have a sufficient number of carbon atoms to render the compound soluble or dispersible in the oil.
• the number of carbon atoms in each group will generally range between 1 to 100, preferably from 1 to 30, and more preferably between 4 to 20.
• Preferred ligands include dialkyldithiophosphate, alkylxanthate, and dialkyldithiocarbamate, and of these dialkyldithiocarbamate is more preferred.
• Organic ligands containing two or more of the above functionalities are also capable of serving as ligands and binding to one or more of the cores. Those skilled in the art will realize that formation of the compounds of the present invention requires selection of ligands having the appropriate charge to balance the core's charge.
• Oil-soluble or oil-dispersible trinuclear molybdenum compounds can be prepared by reacting in the appropriate liquid(s) and/or solvent(s) a molybdenum source such as (NH 4 ) 2 Mo 3 S 13 ⁇ n(H 2 O), where n varies between 0 and 2 and includes non-stoichiometric values, with a suitable ligand source such as a tetralkylthiuram disulfide.
• a molybdenum source such as (NH 4 ) 2 Mo 3 S 13 ⁇ n(H 2 O), where n varies between 0 and 2 and includes non-stoichiometric values
• oil-soluble or oil-dispersible trinuclear molybdenum compounds can be formed during a reaction in the appropriate solvent(s) of a molybdenum source such as of (NH 4 ) 2 Mo 3 S 13 ⁇ n(H 2 O), a ligand source such as tetralkylthiuram disulfide, dialkyldithiocarbamate, or dialkyldithiophosphate, and a sulfur-abstracting agent such cyanide ions, sulfite ions, or substituted phosphines.
• a molybdenum source such as of (NH 4 ) 2 Mo 3 S 13 ⁇ n(H 2 O)
• a ligand source such as tetralkylthiuram disulfide, dialkyldithiocarbamate, or dialkyldithiophosphate
• a sulfur-abstracting agent such cyanide ions, sulfite ions, or substituted phosphines.
• a trinuclear molybdenum-sulfur halide salt such as [M 1 ] 2 [Mo 3 S 7 A 6 ], where M 1 is a counter ion, and A is a halogen such as Cl, Br, or I, may be reacted with a ligand source such as a dialkyldithiocarbamate or dialkyldithiophosphate in the appropriate liquid(s) and/or solvent(s) to form an oil-soluble or oil-dispersible trinuclear molybdenum compound.
• the appropriate liquid and/or solvent may be, for example, aqueous or organic.
• a compound's oil solubility or dispersibility may be influenced by the number of carbon atoms in the ligand's organo groups. In the compounds employed in the present invention, at least 21 total carbon atoms should be present among all the ligand's organo groups. Preferably, the ligand source chosen has a sufficient number of carbon atoms in its organo groups to render the compound soluble or dispersible in the lubricating composition.
• the molybdenum compound is preferably a trinuclear molybdenum dithiocarbamate.
• Natural oils useful as the oil of lubricating viscosity (also known as basestocks) in this invention include animal oils and vegetable oils (e.g. castor, lard oil) liquid petroleum oils and hydrorefined, solvent-treated or acid-treated mineral lubricating oils of the paraffinic, naphthenic and mixed paraffinic-naphthenic types. Oils of lubricating viscosity derived from coal or shale are also useful base oils.
• Alkylene oxide polymers and interpolymers and derivatives thereof where the terminal hydroxyl groups have been modified by esterification or etherification constitute a class of known synthetic lubricating oils useful as basestocks in this invention. These are 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-poly isopropylene glycol ether having an average molecular weight of 1000, diphenyl ether of poly-ethylene 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, for example, the acetic acid esters, mixed C 3 -C 8 fatty acid esters and C 13 Oxo acid diester of tetraethylene glycol.
• Another suitable class of synthetic lubricating oils useful in this invention 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, furnaric acid, adipic acid, linoleic acid dimer, malonic acid, alkylmalonic acids, alkenyl malonic acids) with a variety of alcohols (i-butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol).
• dicarboxylic acids e . g phthalic acid, succinic acid, alkyl succinic acids and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid. sebasic acid, furnaric 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, dicicosyl scbacate, 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.
• 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 and tripentaerythritol.
• Silicon-based oils such as the polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxysiloxane oils and silicate oils comprise another useful class of synthetic lubricants; they include tetracthyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl) silicate, tetra-(4-methyl-2-ethylhexyl) silicate, tetra-(p-tertbutylphenyl) silicate, hexa-(4-methyl-2-pentoxy) disiloxane, poly(methyl) siloxanes and poly(methylphenyl) siloxanes.
• Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (e . g . tricresyl phosphate, trioctyl phosphate, diethyl ester of decylphosphonic acid) and polymeric tetrahydrofurans.
• Unrelined, refined and refined oils can be used in the lubricating oil compositions of the present invention.
• Unrefined oils are those obtained directly from a natural or synthetic source without further purification treatment.
• a shale oil obtained directly from retorting operations a petroleum oil obtained directly from distillation or ester oil obtained directly from an esterification proces and used without further treatment would be an unrefined oil.
• Refined oils are similar to the unrefined oils except they have been further treated in one or more purification steps to improved one or more properties, Many such purification techniques, such as distillation, solvent extraction, acid or base extraction, filtration and percolation are known to those skilled in the art.
• Rerefined oils are obtained by processes similar to those used to obtain refined oils applied to refined oils which have been already used in service. Such 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.
• Lubricating oil compositions for use in any aspect of the present invention may also contain any of the conventional additives listed below (including any additional friction modifiers) which are typically used in a minor amount, e . g . such an amount so as to provide their normal attendant functions. Typical amounts for individual components are also set forth below. All the values listed are stated as mass percent active ingredient in the total lubricating oil composition.
• each of the components may be added directly to the basestock by dispersing or dissolving it in the basestock at the desired level of concentration. Such blending may occur at ambient temperature or at an elevated temperature.
• all the additives except for the viscosity modifier and the pour point depressant are blended into a concentrate (or additive package) that is subsequently blended into basestock to make a finished lubricating oil composition.
• a concentrate or additive package
• the concentrate will typically be formulated to contain the additive(s) in proper amounts to provide the desired concentration in the final lubricating oil composition when the concentrate is combined with a predetermined amount of base oil.
• the concentrate is conveniently made in accordance with the method described in U.S. 4,938,880. That patent describes making a pre-mix of ashless dispersant and metal detergents that is pre-blended at a temperature of at least about 200°C. Thereafter, the pre-mix is cooled to at least 85°C and the additional components are added.
• the final crankcase lubricating oil composition may employ from 2 to 20 mass % and preferably 4 to 15 mass % of the concentrate (or additive package), the remainder being base oil.
• Ashless dispersants maintain in suspension oil-insoluble matter resulting from oxidation of the oil during wear or combustion. They are particularly advantageous for preventing precipitation of sludge and formation of varnish, particularly in gasoline engines.
• Ashless dispersants comprise an oil-soluble polymeric hydrocarbon backbone bearing one or more functional groups that are capable of associating with particles to be dispersed.
• the polymer backbone is by amine, alcohol, amide, or ester polar moieties, often via a bridging group.
• the ashless dispersant may be, for example, selected from oil-soluble salts, esters, amino-esters, amides, imides, and oxazolines of long chain hydrocarbon substituted mono and dicarboxylic acids or their anhydrides; thiocarboxylate derivatives of long chain hydrocarbons; long chain aliphatic hydrocarbons having a polyamine attached directly thereto; and Mannich condensation products formed by condensing a long chain substituted phenol with formaldehyde and polyalkylene polyamine.
• the oil-soluble polymeric hydrocarbon backbone of these dispersants is typically derived from an olefin polymer or polyene, especially polymers comprising a major molar amount ( i . e . greater than 50 mole %) of a C 2 to C 18 olefin ( e . g . ethylene, propylene, butylene, isobutylene, pentene, octene-1, styrene), and typically a C 2 to C 5 olefin.
• the oil-soluble polymeric hydrocarbon backbone may be a homopolymer ( e . g .
• polypropylene or polyisobutylene or a copolymer of two or more of such olefins (e . g . copolymers of ethylene and an alpha-olefin such as propylene or butylene, or copolymers of two different alpha-olefins).
• copolymers include those in which a minor molar amount of the copolymer monomers, for example, I to 10 mole %, is an ⁇ , ⁇ -diene, such as a C 3 to C 22 non-conjugated diolefin (for example, a copolymer of isobutylene and butadiene, or a copolymer of ethylene, propylene and 1,4-hexadiene or 5-ethylidene-2-norbornene).
• a minor molar amount of the copolymer monomers for example, I to 10 mole %
• a minor molar amount of the copolymer monomers for example, I to 10 mole %
• a minor molar amount of the copolymer monomers for example, I to 10 mole %
• a minor molar amount of the copolymer monomers for example, I to 10 mole %
• a minor molar amount of the copolymer monomers for example,
• the viscosity modifier functions to impart high and low temperature operability to a lubricating oil composition.
• the VM used may have that sole function, or may be multifunctional.
• Multifunctional viscosity modifiers that also function as dispersants are also known.
• Suitable viscosity modifiers are polyisobutylene, copolymers of ethylene and propylene and higher alpha-olefins, polymethacrylates, polyalkylmethacrylates, methacrylate copolymers, copolymers of an unsaturated dicarboxylic acid and a vinyl compound, inter polymers of styrene and acrylic ester, and partially hydrogenated copolymers of styrene/isoprene, styrene/butadiene, and isoprene/butadiene, as well as the partially hydrogenated homopolymers of butadiene and isoprene and isoprene/divinylbenzene.
• Metal-containing or ash-forming detergents may be present and these function both as detergents to reduce or remove deposits and as acid neutralizers or rust inhibitors, thereby reducing wear and corrosion and expending engine life.
• Detergents generally comprise a polar head with a long hydrophobic tail, the polar head eompdsing a metal salt of an acid organic compound.
• the salts may contain a substantially stoichiometric amount of the metal in which they are usually described as normal or neutral salts, and would typically have a total base number (TBN), as may be measured by ASTM D-2896 of from 0 to 80. It is possible to include large amounts of a metal base by leading an excess of a metal compound such as an oxide or hydroxide with an acid gas such as carbon dioxide.
• the resulting overbased detergent comprises neutralized detergent as the outer layer of a metal base (e . g . carbonate) micelle.
• a metal base e . g . carbonate
• Such overbased detergents may have a TBN of 150 or greater, and typically from 250 to 450 or more.
• Detergents that may be used include oil-soluble neutral and overbased sulfonates, phenates, sulfurized phenates, thiophosphonates, salicylates, and naphthenates and other oil-soluble carboxylates of a metal, particularly the alkali, e . g . sodium, potassium, lithium and magnesium.
• Preferred are neutral or overbased calcium and magnesium phenates and sulfonates, especially calcium.
• friction modifiers include oil-soluble amines, amides, imidazolines, amine oxides, amidoamines, nitriles, alkanolamides, alkoxylated amines and ether amines; polyol esters; and esters of polycarboxylic acids.
• Dihydrocarbyl dithiophosphate metal salts are frequently used as anti-wear and antioxidant agents.
• the metal may be an alkali or alkaline earth metal, or aluminum, lead, tin, molybdenum, manganese, nickel or copper. They may be prepared in accordance with known techniques by first forming a dihydrocarbyl dithiophosphoric acid (DDPA), usually by reaction of one or more alcohol or a phenol with P 2 S 5 and then neutralizing the formed DDPA with a zinc compound.
• DDPA dihydrocarbyl dithiophosphoric acid
• a dithiophosphoric acid may be made by reacting mixtures of primary and secondary alcohols.
• multiple dithiophosphoric acids can be prepared where the hydrocarbyl groups on one are entirely secondary in character and the hydrocarbyl groups on the others are entirely primary in character.
• any basic or neutral zinc compound may be used but oxides, hydroxides and carbonates are most generally employed. Commercial additives frequently contain an excess of zinc due to use of an excess of the basic zinc compound in the neutralization reaction.
• the lubricating oil compositions of the invention preferably contain no more than 0,8 wt %, such as from 50 ppm to 0.06 wt %, of phosphorus.
• the lubricating oil composition preferably has no more than 0.5 wt %, preferably from 50 ppm to 0.3 wt %, of sulfur, the amounts of sulfur and of phosphorus being measured in accordance with ASTM D5185.
• Oxidation inhibitors or antioxidants reduce the tendency of basestocks to deteriorate in service, which deterioration can be evidenced by the products of oxidation such as sludge and varnish-like deposits on the metal surfaces and by viscosity growth.
• oxidation inhibitors include hindered phenols, alkaline earth metal salts of alkylphenolthioesters having preferably C 5 to C 12 alkyl side chains, calcium nonylphenol sulfide, ashless oil-soluble phenates and sulfurized phenates, phosphosulfurized or sulfurized hydrocarbons, phosphorous esters, metal thiocarbamates, oil-soluble copper compound as described in U.S. 4,867,890, and molybdenum-containing compounds.
• Rust inhibitors selected from the group consisting of nonionic polyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, and anionic alkyl sulfonic acids may be used.
• Copper- and lead-bearing corrosion inhibitors may be used, but are typically not required in the lubricating oil compositions of the present invention.
• thiadiazole polysulfides containing from 5 to 50 carbon atoms, their derivatives and polymers thereof.
• Derivatives of 1,3,4-thiadiazoles such as those described in U.S. Patent Nos. 2,719,125; 2,719,126; and 3,087,932, are typical Other similar material are described in U.S. Patent Nos, 3,821,236; 3,904,537; 4,097,387; 4,107,059; 4,136,043; 4,188,299; and 4,193,882.
• additives are thio and polythio snlfenamides of thiadiazoles such as those described in GB-A-1,560,830. Benzotriazoles derivatives also fall within this class of additive. When these compounds are included in the lubricating oil compositionS, they are preferably present in an amount not exceeding 0.2 wt.% active ingredient.
• a small amount of a demulsifying component may be used.
• a preferred demulsifying component is described in EP-A-330 522. It is obtained by reacting an alkylene oxide with an adduct obtained by reacting a bis-epoxide with a polyhydric alcohol.
• the demulsifier should be used at a level not exceeding 0.1 mass % active ingredient. A treat rate of 0.001 to 0.05 mass % active ingredient is convenient.
• Pour point depressants otherwise known as lube oil improvers, lower the minimum temperature at which the fluid will flow or can be poured.
• Such additives are well-known. Typical of those additives, which improve the low temperature fluidity of the fluid, are C 8 and C 18 dialkyl fumarate/vinyl acetate copolymers and polyalkylmethacrylates.
• Foam control can be provided by many compounds including an antifoamant of the polysiloxane type, for example, silicone oil or polydimethyl siloxane.
• the term “comprising” means the presence of stated features, integers, steps or components, but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. If the term “comprising” (or cognates) is used herein, the term “consisting essentially of” (and its cognates) is within its scope and is a preferred embodiment; consequently the term “consisting of” (and its cognates) is within the scope of “consisting essentially of” and is a preferred embodiment thereof.
• oil-soluble or “oil-dispersible” do not mean that the compounds are soluble, dissolvable, miscible or capable of being suspended in the oil in all proportions. They do mean, however, that the compounds are, for instance, soluble or stably dispersible in the oil to an extent sufficient to exert their intended effect in the environment in which the composition is employed. Moreover, the additional incorporation of other additives such as those described above may affect the solubility or dispersibility of the compounds.
• major amount means in excess of 50 mass % of the composition.
• minor amount means less than 50 mass % of the composition.
• the surface materials used are as set out below:
• Example 1 BS EN1452 pin on Al-Si alloy plate
• a comparison of friction coefficient for Compositions 1, 2 and 3 is set out in Table 1 and Graph 1.
• a comparison of wear coefficient for Compositions 1, 2 and 3 is set out in Graph 2.
• Composition 2 containing the trinuclear organo-molybdenum compound, exhibits a significantly lower friction coefficient than Composition 1 or 2. Furthermore, the coefficient of friction for Composition 2 continues to reduce as the test proceeds, unlike Composition 1 or 3, for which the friction coefficient increases as the test proceeds.
• a comparison of the percentage improvement in friction coefficient of Composition 2 compared to Composition 1 at equivalent points in the test also illustrates the generally increasing reduction of friction coefficient of Composition 2 compared to Composition 1.
• Table 1 illustrates that Composition 2 performs significantly more effectively at reducing the coefficient of friction than Composition 3, which generally performs less well than Composition 1 (as indicated by the negative prefix).
• Composition 5 exhibits a lower friction coefficient than Composition 4.
• addition of ZDDP to the trinuclear organo-molybdenum containing composition, Composition 2 has a negative impact on the friction reduction associated with the trinuclear molybdenum campound
• the above graph shows that the primary ZDDP of Composition 5 has a less detrimental effect on the friction coefficient than secondary ZDDP of Composition 4.
• Table 2 (Friction Coefficient) Time (min) Comp. 2 Comp.
• Example 2 BS EN1452 pin on a BS EN31 plate
• a comparison of friction coefficient for Compositions 1, 2 and 3 is set out in Table 3 and Graph 4.
• a comparison of wear coefficient for Compositions 1, 2 and 3 is set out in Graph 5.
• composition 2 comprising the trinuclear organo-molybdenum compound
• the percentage improvement figures in Table 3 illustrate that Composition 2 provides an increasingly better friction performance when compared with either Composition 1 or 3, as the test proceeds.
• Graph 4 and Table 3 also illustrates that Composition 3, comprising dinuclear molybdenum actually exhibits coefficients of friction that are higher than Composition 1, with no molybdenum additive.
• Table 3 (Friction Coeficient) Time (min) Comp. 1 Comp. 2 Comp.3 Comp. 2 % Improvement Comp.
• lubricating Composition 4 effects a greater reduction in friction coefficient than either of lubricating Compositions 2 or 5.
• addition of secondary ZDDP additive (Composition 4) to a lubricant containing trinuclar molybdenum improves the coefficient of friction.
• addition of primary ZDDP (Composition 5) to the lubricant in place of secondary ZDDP has a detrimental effect of the coefficient of friction.

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• 2005
  • 2005-06-08 EP EP05105029A patent/EP1624044A1/de not_active Withdrawn

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