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
  • C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
  • C10M169/06—Mixtures of thickeners and additives
• • 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
  • C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, 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
  • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
  • C10M2201/06—Metal compounds
  • C10M2201/065—Sulfides; Selenides; Tellurides
  • C10M2201/066—Molybdenum sulfide
• • 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
  • C10M2203/00—Organic non-macromolecular hydrocarbon compounds and hydrocarbon fractions as ingredients in lubricant compositions
  • C10M2203/10—Petroleum or coal fractions, e.g. tars, solvents, bitumen
  • C10M2203/1006—Petroleum or coal fractions, e.g. tars, solvents, bitumen used as base material
• • 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
  • C10M2203/00—Organic non-macromolecular hydrocarbon compounds and hydrocarbon fractions as ingredients in lubricant compositions
  • C10M2203/10—Petroleum or coal fractions, e.g. tars, solvents, bitumen
  • C10M2203/102—Aliphatic fractions
  • C10M2203/1025—Aliphatic fractions used as base material
• • 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
  • C10M2203/00—Organic non-macromolecular hydrocarbon compounds and hydrocarbon fractions as ingredients in lubricant compositions
  • C10M2203/10—Petroleum or coal fractions, e.g. tars, solvents, bitumen
  • C10M2203/106—Naphthenic fractions
  • C10M2203/1065—Naphthenic fractions used as base material
• • 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
  • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
  • C10M2205/02—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
  • C10M2205/028—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms
  • C10M2205/0285—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms used as base material
• • 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
  • C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
  • C10M2207/28—Esters
  • C10M2207/282—Esters of (cyclo)aliphatic oolycarboxylic acids
• • 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
  • C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
  • C10M2207/28—Esters
  • C10M2207/282—Esters of (cyclo)aliphatic oolycarboxylic acids
  • C10M2207/2825—Esters of (cyclo)aliphatic oolycarboxylic acids used as base material
• • 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
  • C10M2219/04—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions containing sulfur-to-oxygen bonds, i.e. sulfones, sulfoxides
  • C10M2219/044—Sulfonic acids, Derivatives thereof, e.g. neutral salts
  • C10M2219/0445—Sulfonic acids, Derivatives thereof, e.g. neutral salts used as thickening agents
• • 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
  • C10M2219/04—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions containing sulfur-to-oxygen bonds, i.e. sulfones, sulfoxides
  • C10M2219/046—Overbasedsulfonic acid salts
  • C10M2219/0466—Overbasedsulfonic acid salts used as thickening agents
• • 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
  • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
  • C10N2020/01—Physico-chemical properties
  • C10N2020/02—Viscosity; Viscosity index
• • 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
  • C10N2030/76—Reduction of noise, shudder, or vibrations
• • 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
  • C10N2040/04—Oil-bath; Gear-boxes; Automatic transmissions; Traction drives
  • C10N2040/046—Oil-bath; Gear-boxes; Automatic transmissions; Traction drives for traction drives
• • 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
  • C10N2050/00—Form in which the lubricant is applied to the material being lubricated
  • C10N2050/10—Semi-solids; greasy

Definitions

• the present invention relates to a lubricating grease which is intended primarily for use in constant velocity universal joints, especially ball joints or tripod joints, which are used in the drivelines of motor vehicles. Further, the present invention relates to a constant velocity joint comprising the grease composition in accordance with the present invention.
• NVH noise, vibration and harshness
• Constant velocity joints also have sealing boots of elastomeric material which are usually of bellows shape, one end being connected to the outer part of the CVJ and the other end to the interconnecting or output shaft of the CVJ.
• the boot retains the grease in the joint and keeps out dirt and water.
• the two main types of material used for CVJ boots are polychloroprene rubber (CR) and thermoplastic elastomer (TPE), especially ether-ester block co-polymer thermoplastic elastomer (TPC-ET).
• CR polychloroprene rubber
• TPE thermoplastic elastomer
• TPC-ET ether-ester block co-polymer thermoplastic elastomer
• Typical CVJ greases have base oils which are blends of naphthenic (saturated rings) and paraffinic (straight and branched saturated chains) mineral oils. Synthetic oils may also be added. It is known that said base oils have a large influence on the deterioration (swelling or shrinking) of both boots made of CR and TPC-ET. Both mineral and synthetic base oils extract the plasticisers and other oil soluble protective agents from the boot materials. Paraffinic mineral oils and poly- ⁇ -olefin (PAO) synthetic base oils diffuse very little into especially boots made of rubber material causing shrinkage, but on the other hand naphthenic mineral oils and synthetic esters diffuse into boot materials and act as plasticisers and can cause swelling.
• PAO poly- ⁇ -olefin
• the exchange of plasticiser or plasticiser compositions for the naphthenic mineral oil can significantly reduce the boot performance, especially at low temperatures, and may cause the boot to fail by cold cracking, ultimately resulting in failure of the CVJ. If significant swelling or softening occurs, the maximum high speed capability of the boot is reduced due to the poor stability at speed and/or excessive radial expansion.
• US 6,656,890 B1 suggests a special base oil combination comprising 10 to 35% by weight of one or more poly- ⁇ -olefins, 3 to 15% by weight of one or more synthetic organic esters, 20 to 30% by weight of one or more naphthenic oils, the remainder of the combination being one or more paraffinic oils, and, further, a lithium soap thickener, and a sulphur-free friction modifier, that may be a organo-molybdenum complex, and molybdenum dithiophosphate, and a zinc dialkyldithiophosphate and further additives such as corrosion inhibitors, anti-oxidants, extreme pressure additives, and tackiness agents.
• SRV abbreviation for the German words Schwing Institute, Reibung, Verschlei ⁇
• a grease composition primarily for use in constant velocity joints, which has a good compatibility with boots made of rubber or thermoplastic elastomer, and which also gives enhanced endurance, low wear and low friction in use in CVJ.
• the base oil composition used in the grease composition in accordance with the present invention comprises poly- ⁇ -olefines, napthenic oils, paraffinic oils, and/or synthetic organic esters.
• a base oil composition as disclosed in US 6,656,890 B1 may preferably be used, the disclosure of which is incorporated insofar herein by reference,.
• any further kind of base oil composition especially a blend of mineral oils, a blend of synthetic oils or a blend of a mixture of mineral and synthetic oils may be used.
• the base oil composition should preferably have a kinematic viscosity of between about 32 and about 250mm 2 /s at 40°C and between about 5 and about 25mm 2 /s at 100 0 C.
• the mineral oils preferably are selected from the group comprising at least one naphthenic oil and/or at least one paraffinic oil.
• the synthetic oils usable in the present invention are selected from a group comprising at least one poly- ⁇ -olefin (PAO) and/or at least one synthetic organic ester.
• the organic synthetic ester is preferably a di-carboxylic acid derivative having subgroups based on aliphatic alcohols.
• the aliphatic alcohols have primary, straight or branched carbon chains with 2 to 20 carbon atoms.
• the organic synthetic ester is selected from a group comprising sebacic acid-bis(2-ethylhexylester) ("dioctyl sebacate” (DOS)), adipic acid-bis-(2-ethylhexylester) (“dioctyl adipate” (DOA)), and/or azelaic acid- bis(2-ethylhexylester) (“dioctyl azelate (DOZ)).
• DOS dioctyl sebacate
• DOA dioctyl adipate
• DOZ azelaic acid- bis(2-ethylhexylester)
• poly- ⁇ -olefins are selected having a viscosity in a range from about 2 to about 40 centistokes at 100 0 C.
• the naphthenic oils selected for the base oil composition have preferably a viscosity in a range between about 3 to about 370 mm 2 /s, more preferably about 20 to about 150 mm 2 /s at 40 0 C, whereas if paraffinic oils were present in the base oil composition, preferably the paraffinic oils have a viscosity in a range between about 9 to about 170 mm 2 /s at 40°C.
• the at least one calcium sulphonate soap and/or calcium sulphonate complex soap used as a thickener in the grease composition in accordance with the present invention is, in principle, a reaction product of aliphatic or fatty acids and/or hydroxy aliphatic and/or fatty acids.
• the fatty acids or hydroxy fatty acids are selected preferably from a group comprising 12 to 30, preferably 12 to 24, most preferably 12 to 18 carbon atoms.
• the aliphatic and/or fatty acids may be selected from a group comprising dodecanoic acid, palmitic acid, stearic acid, oleic acid, ricinoleic acid and/or 12-hydroxystearic acid.
• the calcium sulfonate that may be used in the preparation of the calcium sulfonate grease and/or the calcium sulfonate complex grease is selected from the group comprising at least one calcium sulfonate and/or at least one overbased calcium sulfonate.
• Overbased calcium sulfonates are preferred in accordance with the present invention, especially overbased calcium sulfonates having a metal ratio of about 6 to 35.
• a calcium sulfonate soap that may be used as a thickener may be prepared from the reaction of the aforesaid calcium sulfonate components and aliphatic and/or fatty acids and/or hydroxy and/or fatty acids in the presence of other agents, especially converting agents, comprising, among others, water, alcohols, for instance biphenol, isobutanol, n- pentanol, or mixtures thereof or mixtures of alcohols with water, alkylene glycols, monoloweralkyl ethers of alkylene glycols such as monomethylether of ethylene glycol, lower aliphatic carboxylic acids, for example acetic acid and propionic acid, ketones, aldehydes, amines, phosphorus acids, alkyl and aromatic amines, imidazoilines, alkanolamines, boron acids, including boric acid, tetraboric acid, metaboric acid, and esters of such boron acids, and, also, carbon
• Calcium sulphonate complex soaps that may be used as a thickener in accordance with the present invention may be used prepared from at least one aliphatic and/or fatty acid or hydroxyaliphatic and/or fatty acid, at least one of the calcium sulphonate compounds mentioned above together with a complexing agent, for example a borate of one or more dicarboxylic acids or a mixture of short and/or medium chained carboxylic acids.
• a complexing agent for example a borate of one or more dicarboxylic acids or a mixture of short and/or medium chained carboxylic acids.
• a calcium sulphonate complex soap as a thickener in accordance with the present invention allows the grease composition according to the present invention to operate up to a temperature of about 180 0 C, whereas simple calcium sulphonate soaps that may be used as a thickener in accordance with the present invention, the grease composition will only operate up to a temperature of about 120 0 C. However, mixtures of all of the aforesaid soaps may also be used.
• the at least one molybdenum containing additive that is present in the grease composition in accordance with the present invention is preferably selected from a group comprising at least one molybdenum dithiocarbamate, at least one molybdenum dithiophosphate, MoS 2 , at least one S-free and P-free organic molybdenum compound, and/or at least one tri-nuclear molybdenum compound.
• the at least one tri-nuclear molybdenum compound is of the following general formula
• the number of carbon atoms present in the tri-nuclear molybdenum compound among all the ligands, organo groups is at least 21 carbon atoms, preferably at least 25, more preferably at least 30, and most preferably at least 35.
• Tri-nuclear molybdenum compounds usable in the present invention are disclosed in US 6,172,013 B1 , the disclosure of which is incorporated in the present invention insofar by reference. The presence of at least 0.25% by weight of the tri-nuclear molybdenum compound is preferred and significantly lowers the friction coefficient as well as the wear when used in CVJs.
• the at least one molybdenum dithiophosphate (MoDTP) and/or molybdenum dithiocarbamate (MoDTC) is preferably present in the grease composition according to the present invention in an amount in a range between about 0.3 % by weight, more preferred about 0.5 % by weight, most preferred about 1.0 % by weight, to about 3.5 % by weight, most preferred about 3 % by weight, in each case referred to the total amount of the grease composition.
• any further molybdenum containing compound may be present in the grease composition according to the present invention as component c), of which organic molybdenum compounds are preferred.
• the grease composition according to the present invention may contain one or more MoDTC and/or MoDTP, and especially mixtures thereof.
• the MoDTP according to the present invention is of the following general formula:
• X or Y represents S or O and each of R 1 to R 4 inclusive may be the same or different and each represents a primary (straight chain) or secondary (branched chain) alkyl group having between 6 and 30 carbon atoms.
• the MoDTC according to the present invention is of the following general formula: [(R 5 )(R 6 )N-CS-S] 2 -Mo 2 O m S n (III)
• the molybdenum containing additive is selected from a group comprising at least one molybdenum dithiocarbamate and at least one tri-nuclear molybdenum compound.
• the grease composition comprises 0.2 % by weight to 5.0 % of at least one tri-nuclear molybdenum compound, preferably 0.25 % by weight to 3 % by weight, most preferably 0.3 % by weight to 2 % by weight, and much more preferably 0.3 % by weight to 1.25 % by weight.
• the grease composition comprises 0.25 to 5 % by weight of at least one solid or liquid molybdenum dithiocarbamate, preferably 0.5 % by weight to 3 % by weight, most preferably 0.8 % by weight to 2 % by weight.
• the molybdenum dithiocarbamate is selected from a group comprising at least one solid molybdenum dithiocarbamate.
• the grease composition further comprises at least one anti-oxidation agent, at least one corrosion inhibitor, at least one anti-wear agent, at least one wax, at least one friction modifier and/or at least one extreme pressure agent.
• At least one zinc compound additive is used as a friction modifier.
• the most preferred zinc compound additive is selected from the group comprising at least one of zinc dithiophosphates (ZnDTP) and/or zinc dithiocarbamates (ZnDTC), and ZnDTPs are most preferred.
• the zinc dithiophosphate is preferably selected from the group of zinc dialkyldithiophosphate of the following general formula:
• R 7 , R 8 , R 9 and R 10 represent a combination of primary and secondary alkyl groups, each having 3 to 8 carbon atoms.
• the zinc dithiocarbamate may be preferably selected from zinc dialkyldithiocarbamate of the following general formula:
• R 11 , R 12 , R 13 , and R 14 may be same or different and each represents an alkyl group having 1 to 24 carbon atoms or an aryl group having 6 to 30 carbon atoms.
• the EP agent is preferably a metal-free polysulfide or a mixture thereof, e.g. sulphurised fatty acid methyl ester agents, with preferably a viscosity of about 25mm 2 /s at 40 0 C, being present preferably in an amount between about 0.1 to about 3 % by weight, preferably 0.3 to about 2 % by weight, referred to the total amount of the grease composition.
• the total inactive sulphur amount of the EP agent at room temperature preferably ranges from about 8 to about 50 % by weight, preferably to about 45 % by weight.
• the active sulphur amount as measured in accordance with ASTM D1662 may be about up to 1 % by weight, preferably up to about 8 % by weight at 100 0 C, and preferably up to about 20 % by weight at 140 0 C, the weight percent being referred to the amount of the EP agent itself.
• Such EP agents exhibit excellent effects with respect to the prevention of scuffing of contacting CVJ internal components. If the sulphur content exceeds the upper limit defined above, it may promote the initiation of rolling contact fatigue and wear of the contacting metal components and may lead to degradation of the CVJ boot material.
• the grease composition of the present invention may comprise an amine, preferably an aromatic amine, more preferably phenyl- ⁇ -naphthylamine or di- phenylamine or derivatives thereof.
• the anti-oxidation agent is used to prevent deterioration of the grease composition associated with oxidation.
• the grease composition according to the present invention may range between about 0.1 to about 2 % by weight, referred to the total amount to the grease composition, of an anti-oxidant agent in order to inhibit the oxidation degradation of the base oil composition, as well as to lengthen the life of the grease composition, thus prolonging the life of the CVJ.
• the last operation before the assembly of CVJ is a wash to remove machining debris, and it is therefore necessary for the grease to absorb any traces of remaining water and to prevent the water from causing corrosion and adversely effecting the performance of the CVJ, thus a corrosion inhibitor is required.
• the grease composition according to the present invention may comprise at least one metal or dimetal salt selected from the group consisting of metal salts of oxidised waxes, metal salts of petroleum sulphonates, especially prepared by sulphonating aromatic hydrocarbon components present in fractions of lubricating oils, and/or metal salts of alkyl aromatic sulphonates, such as dinonylnaphthalene sulphonic acids, alkylbenzene sulphonic acids, or overbased alkylbenzene sulphonic acids.
• the metal salts include sodium salts, potassium salts, calcium salts, magnesium salts, zinc salts, quaternary ammonium salts, the calcium salts being most preferred. Calcium salts of oxidised waxes also ensure an excellent effect. Especially preferred is disodium sebacate as corrosion inhibitor.
• Anti-wear agents according to the present invention prevent a metal-to-metal contact by adding film-forming compounds to protect the surface either by physical absorption or chemical reaction.
• ZnDTP-compounds may also be used as anti-wear agents.
• anti- corrosion agents according to the present invention preferably calcium sulphonate salts are used, preferably an amount between about 0.5 to about 3% by weight, referred to the total amount of the grease composition.
• the grease composition of the present invention may comprise any kind of waxes, preferably oiliness waxes, known in the state of the art to be used in grease composition or mixtures thereof, of which montan waxes, especially ester montan waxes being a reaction product of at least one acid montan wax with an ester, and polyolefin waxes including micronized montan and/or polyolefin waxes, or mixtures thereof are most preferred.
• Montan waxes in the sense of the present invention preferably comprises esters of C 22 -C 34 -fatty acids and probably wax alcohols having 24 to 28 carbon atoms.
• Esters may be present in the montan wax in accordance with the present invention in an amount in a range of about 35% by weight to about 70% by weight. Further, free fatty acids as well as free wax alcohols as well as montan resins may be present.
• Useful montan waxes are offered for example by the company Clariant GmbH, 86005 Augsburg, Germany, especially montan waxes offered and sold under the trade name "Licowax”.
• Usable polefin waxes in the sense of the present invention are especially polypropylene and/or polyethylene waxes or mixtures thereof, also including modified polyolefin waxes, obtained especially by copolymerization of ethylene with useful co-monomers like vinyl esters or acrylic acid.
• the wax has preferably a viscosity of at least about 50 mPa * s at 100 0 C, more preferred of at least about 100 mPa*s at 100 0 C, and most preferred of at least about 200 mPa*s at 100°C, measured in accordance with DIN 53 018.
• the wax used in the grease composition may be supplied as a powder or flakes, and is added to the grease composition with a long perod of stirring, preferably at elevated temperatures, especially at temperatures about 80 0 C to about 100 0 C.
• the grease composition claimed comprises 0.3 wt.-% to 2 wt.-%, preferably to 1.25 wt.-%, of at least one trinuclear molybdenum compound and 0.8 wt.-% to 3 wt.-%, preferably to 2 wt.-%, of at least one molybdenum dithiocarbamate.
• the grease composition claimed comprises 65 wt.-% to 86.9 wt.-% of a base oil composition, 16 wt.-% to 20 wt.-% of at least one calcium sulphonate soap and/or calcium sulphonate complex soap, 0.3 wt.- % to 2 wt. -% of at least one trinuclear molybdenum compound and 0.3 wt.-% to 3 wt.-% of at least one molybdenum dithiocarbamate.
• the grease composition according to the present invention comprises 16 wt.-% to 20 wt.-% of at least one calcium sulphonate soap and/or calcium sulphonate complex soap, 0.3 wt.-% to 0.7 wt.-% of at least a tri-nuclear molybdenum compound, 0.75 wt.-% to 1.8 wt.-% of at least one molybdenum diothiocarbamate, and 66.45 wt.-% to 86.9 wt.-% of a base oil composition.
• the grease composition claimed may further comprise other agents as mentioned above.
• the present invention refers to the use of a grease composition in accordance with the present invention in constant velocity joints, and, further, to a constant velocity joint comprising a grease composition as claimed.
• the constant velocity joint especially encompasses a boot, the boot being filled with the grease composition in accordance with the present invention, at least in part, the boot having a first attachment region which is assigned to a joint, and a second attachment region which is assigned to a shaft.
• the boot may be fixed with usual clamp devices on the joint and/or shaft.
• SRV tests are carried out using an Optimol Instruments SRV tester.
• Flat disc lower specimen made of the 100Cr6 standard bearing steel from Optimol Instruments Pr ⁇ ftechnik GmbH, Westendstrasse 125, Kunststoff, properly cleaned using a solvent are prepared and contacted with the grease composition to be examined.
• the SRV test is an industry standard test and is especially relevant for the testing of greases for CVJ.
• the test consists of an upper ball specimen with a diameter of 10 mm made from 100Cr6 bearing steel reciprocating under load on the flat disc lower specimen indicated above.
• W r V/L [ ⁇ m 3 /m]
• L the total sliding distance in the tests.
• the commercial greases used in comparative examples A and B are Axel CaSX 51646, obtained from Axel Christiernsson B. V., Heijningen, Netherlands, (comparative example A) and Super Grease 2 obtained from Tianjin Lubricant and Grease Co. Ltd. (Jinzhi), Sinopec Corp., Tianjin, P. R. China (comparative example B).
• the base oil composition used has a kinematic viscosity of about 165 mm 2 /s at 40 0 C and about 16 mm 2 /s at 100 0 C.
• the base oil blend may be a mixture of one or more paraffinic oils in a range between about 10 to about 60 % by weight, preferably about 20 to 40% by weight, one or more naphthenic oils in a range between about 30 to about 80 % by weight, preferably about 55 to about 80% by weight, and, if necessary, one or more poly- ⁇ -olefins (PAO) in a range between about 5 to about 40 % by weight, referred to the total amount of the oil mixture.
• PAO poly- ⁇ -olefins
• the oil blend may further contain DOS in a range between about 2 to about 10 % by weight, referred to a total amount of the oil mixture.
• the concrete oil blend used in the examples is made of 73% by weight of naphthenic oil SR130, produced by AB Nyna ' s Petroleum, Sweden, 25% by weight of paraffinc oil NS650, obtained by Kuwait Petroleum Europoort B. V, Europoort, Netherlands, and 2% by weight of DOS.
• the naphthenic oils are selected with a range of viscosity between about 20 to about 180 mm 2 /s at 40°C, paraffinic oils between about 25 to about 400 mm 2 /s at 40°C, and PAO between about 6 and about 40 mm 2 /s at 100 0 C.
• the calcium sulphonate soap used in the examples of the present invention is an overbased calcium sulphonate soap obtained from a reaction of overbased calcium sulphonate with a metal ratio of about 6 to 35 with 12-hydroxystearic acid in the presence of a solvent neutral oil, calcium carbonate, isopropyl alcohol and phosphoric acid.
• a possible method for producing the calcium sulphonate soap used is described in US 5,126,062.
• TMS Tri-molecular molybdenum compound
• the tri-molecular molybdenum compound used in the grease compositions according to the present invention is a sulphur-containing tri-nuclear molybdenum compound obtainable under the trade name C9455B by lnfineum International Ltd., UK. Its structure is defined in US 6, 172,013 B1.
• molybdenum dithiocarbamate sold under the trade name Sakuralube 200 ( MoDTC S-200) in the liquid state, produced by Asahi Denka Co. Limited, Japan, is used as well as a S-free and P-free organic molybdenum additive sold under the trade name S- 701 by Asahi Denka Co. Limited, Japan, being a molybdenum amine complex with the general formula R 2 N-Mo x OyH, as well as usual MoS 2 .
• a zinc compound additive namely zinc dithiophosphate ZnDTP, sold by lnfineum International Ltd., Oxfordshire, UK 1 under the trade name C9425, is used, being a zinc dialkyldithiophosphate with primary and/or secondary alkyl groups, especially having 3 to 8 C-atoms, preferably having 4 to 5 C-atoms, diluted with mineral oil.
• the results from the SRV-measurements of the friction coefficient as well as the welding load measurements of Examples A1 to A8 may be derived from Fig. 1. and Fig. 2.
• the lowest friction coefficient, and, however, the highest wear is measured when adding a simple MoS 2 , whereas a very low wear as measured with respect to Example A3 with an increased friction coefficient compared with Example A1 being a grease composition not in accordance with the present invention only composed of the base oil and a calcium sulphonate soap.
• Examples A2 and A5 show good results with respect to the wear.
• Examples B1 to B3 the amount of the TNMoS is amended, wherein in Examples B4 to B7 the amount of MoDTC solid is amended.
• Examples B8 to B10 refer to mixtures of 0.5 wt.-% TNMoS to different amounts of MoDTC solid.
• Example B3 shows the lowest friction coefficient, however, the results for the wear are only in the midrange of the results obtained. Further, low friction coefficients were measured with respect to Examples B9 to B10, of which Example B9 shows one of the lowest wear measured. Said test results show that especially combinations of different molybdenum containing compounds are preferable, and that the ranges of the molybdenum compounds used are very sensitive with respect to the friction coefficient and wear measured.
• composition C4 being a composition of 1.5 wt.-% of MoDTC solid in the solid state and the tri-nuclear molybdenum compound in an amount of 0.5 wt.-% is most preferred, because both the friction coefficient as well as the wear are considerably lower when compared to the results of the other compositions.
• the grease composition in accordance with the present invention has an advantageous and significant influence on the friction coefficient and the wear, leading to a good extreme pressure performance.
• Especially preferred are combinations of two or three different molybdenum containing compounds being added to the grease composition in an amount up to 3.5 weight % in total, of which the addition of a tri-nuclear molybdenum compound as well as a molybdenum dithiocarbamate, preferably in the solid state, in combination are most preferred.

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• 2008
  • 2008-04-01 ES ES08734931.2T patent/ES2436776T3/es active Active
  • 2008-04-01 CN CN200880128562.7A patent/CN101981169B/zh active Active
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