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
  • C10M169/02—Mixtures of base-materials and thickeners
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  • 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
  • C10M2205/0206—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers used as base material
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  • 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
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  • 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
  • C10M2207/04—Ethers; Acetals; Ortho-esters; Ortho-carbonates
  • C10M2207/0406—Ethers; Acetals; Ortho-esters; Ortho-carbonates used as base material
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  • 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
  • C10M2207/10—Carboxylix acids; Neutral salts thereof
  • C10M2207/12—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms
  • C10M2207/121—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of seven or less carbon atoms
  • C10M2207/123—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of seven or less carbon atoms polycarboxylic
  • C10M2207/1236—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of seven or less carbon atoms polycarboxylic used as thickening agent
• • 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
  • C10M2207/10—Carboxylix acids; Neutral salts thereof
  • C10M2207/12—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms
  • C10M2207/125—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of eight up to twenty-nine carbon atoms, i.e. fatty acids
  • C10M2207/127—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of eight up to twenty-nine carbon atoms, i.e. fatty acids polycarboxylic
  • C10M2207/1276—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of eight up to twenty-nine carbon atoms, i.e. fatty acids polycarboxylic used as thickening agent
• • 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
  • C10M2207/10—Carboxylix acids; Neutral salts thereof
  • C10M2207/12—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms
  • C10M2207/125—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of eight up to twenty-nine carbon atoms, i.e. fatty acids
  • C10M2207/128—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of eight up to twenty-nine carbon atoms, i.e. fatty acids containing hydroxy groups; Ethers thereof
  • C10M2207/1285—Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of eight up to twenty-nine carbon atoms, i.e. fatty acids containing hydroxy groups; Ethers thereof 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
  • C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
  • C10M2207/28—Esters
  • C10M2207/283—Esters of polyhydroxy compounds
• • 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
  • C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
  • C10M2213/06—Perfluoro polymers
  • C10M2213/0606—Perfluoro polymers 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
  • C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
  • C10M2213/06—Perfluoro polymers
  • C10M2213/062—Polytetrafluoroethylene [PTFE]
  • C10M2213/0626—Polytetrafluoroethylene [PTFE] 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
  • C10M2215/00—Organic non-macromolecular compounds containing nitrogen as ingredients in lubricant compositions
  • C10M2215/02—Amines, e.g. polyalkylene polyamines; Quaternary amines
  • C10M2215/06—Amines, e.g. polyalkylene polyamines; Quaternary amines having amino groups bound to carbon atoms of six-membered aromatic rings
  • C10M2215/064—Di- and triaryl 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
  • C10M2215/00—Organic non-macromolecular compounds containing nitrogen as ingredients in lubricant compositions
  • C10M2215/08—Amides
  • C10M2215/0813—Amides used as thickening agents
• • 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
• • 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
  • C10N2030/08—Resistance to extreme temperature
• • 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
  • C10N2030/68—Shear stability
• • 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
  • C10N2040/02—Bearings
• • 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
• • 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
  • C10N2040/14—Electric or magnetic purposes
  • C10N2040/17—Electric or magnetic purposes for electric contacts
• • 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
• • 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
  • C10N2070/00—Specific manufacturing methods for lubricant compositions

Definitions

• the present invention relates to a lubricating grease composition and a method for producing the same. More particularly, the present invention relates to a lubricating grease composition comprising a base oil mixture of a non-fluorine-based base oil and a fluorine-based base oil, which are incompatible with each other; and a method for producing the composition.
• Conventional fluorine-based greases comprise a perfluoropolyether oil as a base oil, a homopolymer of tetrafluoroethylene [PTFE], a copolymer of tetrafluoroethylene and hexafluoropropene [HFP], or the like as a thickener, and small amounts of additives, such as rust inhibitors. They are used under severe conditions requiring, for example, low-temperature characteristics, high-temperature durability, oxidation stability, and chemical resistance.
• PTFE tetrafluoroethylene
• HFP hexafluoropropene
• the base oil and thickener both contain fluorine, and thus have such problems as high cost; poor compatibility with materials to be lubricated, such as resins, metals, rubber, etc.; failure to form oil films necessary for lubrication under high-load conditions, causing abrasion, and resulting in increased friction coefficients, so that the torque transmission efficiency is lowered; and poor rust prevention and corrosion resistance.
• lubricating grease compositions comprising a base oil mixture of a non-fluorine-based base oil and a fluorine-based base oil are as follows:
• Patent Document 1 discloses a grease comprising a hydrogenated mineral oil and/or synthetic lubricating oil, a fluoropolyether oil, and an organic or inorganic thickening agent, wherein the weight ratio of the lubricating oil and the fluoropolyether oil to the thickening agent is 97:3 to 80:20, and the weight ratio of the lubricating oil to the fluoropolyether oil is 95:5 to 60:40.
• the grease is evaluated for abrasion resistance, load resistance, and bearing durability.
• an ester oil mixed with an aliphatic lithium complex soap (a lithium complex soap of azelaic acid and 12-hydroxystearic acid) is used.
• Patent Document 2 discloses a ball-and-roller bearing for an electromagnetic clutch and an idler pulley, the bearing being filled with a grease mixture of a fluorine-based grease comprising a perfluoropolyether oil as a base oil and PTFE as a thickener, and a grease other than fluorine-based grease.
• the ball-and-roller bearing has a longer seizure life at a high temperature exceeding 180° C. and enhanced resistance to rust.
• Hydrocarbon-based and ester-based oils, etc. are used as the base oil for non-fluorine-based grease, and lithium, sodium, barium, calcium, and other metal complex soaps are used as metal complex soap thickeners.
• Patent Document 2 disclose a method for producing a lithium complex soap thickener by a two-step saponification reaction comprising saponifying 12-hydroxystearic acid and lithium hydroxide, and then adding dibasic acid and lithium hydroxide, followed by saponification.
• Patent Document 3 discloses a grease mixture, using for a ball-and-roller bearing, comprising a metal complex soap-based grease and a fluorine-based grease at a specific ratio, the metal complex soap-based grease containing 8 to 35 mass % of thickener, and the fluorine-based grease containing a perfluoropolyether oil as a base oil and 15 to 42.5 mass % of PTFE as a thickener, wherein the total amount of the thickeners is 20 to 30 mass %.
• Hydrocarbon-based and ester-based oils, etc. are used as the base oil for non-fluorine-based grease, and lithium, sodium, barium, calcium, and other metal complex soaps are used as metal complex soap thickeners.
• Patent Document 3 disclose a method for producing a lithium complex soap thickener by a two-step saponification reaction comprising saponifying 12-hydroxystearic acid and lithium hydroxide, and then adding dibasic acid and lithium hydroxide, followed by saponification.
• Patent Document 4 discloses a ball-and-roller bearing for a fuel cell in which a fluorine-based grease comprising a fluorine oil as a base oil and a fluororesin as a thickener, and a grease other than fluorine-based grease are enclosed; and a pressure-feeder for a fuel cell system providing the ball-and-roller bearing.
• Patent Document 4 merely indicates that hydrocarbon-based and ester-based oils, etc. are used as the base oil for non-fluorine-based grease, and that lithium, sodium, barium, calcium, and other metal complex soaps are used as metal complex soap thickeners.
• Patent Document 5 discloses a lubricating grease composition comprising a straight-chain perfluoropolyether oil, a synthetic lubricating oil other than the straight-chain perfluoropolyether oil, and a thickener, wherein lithium soaps or lithium complex soaps, such as saturated or unsaturated aliphatic monocarboxylic acid lithium salts or aliphatic dicarboxylic acid lithium salts, are used.
• lithium soaps or lithium complex soaps such as saturated or unsaturated aliphatic monocarboxylic acid lithium salts or aliphatic dicarboxylic acid lithium salts
• Patent Document 6 which was also filed by the present applicant, discloses a lubricating grease composition comprising a perfluoropolyether oil, and, as a thickener, at least one selected from an aliphatic dicarboxylic acid metal salt, a monoamide monocarboxylic acid metal salt, and a monoester carboxylic acid metal salt.
• the lubricating grease composition reportedly has excellent abrasion resistance to mating materials, leakage resistance, washing properties, etc., and satisfies the cost requirements.
• the monoamide carboxylic acid metal salts used in Patent Document 6 are obtained as amide and metal salt of the each dicarboxylic group of dicarboxylic acids. It is reported that primary, secondary, or unsaturated aliphatic amines are used as amines to be amidated, and Li, Na, K, Ca, Ba, Mg, Cu, Fe, Co, Zn, Al, and other salts are used as metal salts.
• Patent Document 1 JP-A-7-268370
• Patent Document 2 JP-A-2003-239997
• Patent Document 3 JP-A-2004-028326
• Patent Document 4 JP-A-2004-190688
• Patent Document 5 JP-A-2003-096480
• Patent Document 6 JP-A-2001-354986
• An object of the present invention is to provide a lubricating grease composition prepared by adding a metal soap-based thickener to a fluorine-based base oil, the composition having improved abrasion resistance and ensuring cost reduction; and a method for producing the composition.
• a lubricating grease composition comprising a fluororesin powder and a complex metal soap thickener of aliphatic dicarboxylic acid and monoamide monocarboxylic acid contained in a base oil mixture of a non-fluorine-based base oil and a fluorine-based base oil, which are incompatible with each other.
• the lubricating grease composition can be produced by kneading a non-fluorine-based grease and a fluorine-based grease preferably using a three-roll mill; the non-fluorine-based grease being prepared by stirring a non-fluorine-based base oil, aliphatic dicarboxylic acid, and monoamide monocarboxylic acid under heating, and adding metal hydroxide thereto to form a complex metal soap in the non-fluorine-based base oil; and the fluorine-based grease being prepared from a fluorine-based base oil and a fluororesin powder.
• a complex metal soap a complex barium metal soap is preferably used.
• the lubricating grease composition of the present invention has excellent abrasion resistance, load resistance, heat resistance (degree of oil separation), and shear stability (consistency change). Particularly, compared with the lubricating grease composition disclosed in Patent Document 6, the lubricating grease composition of the present invention has improved abrasion resistance and ensures cost reduction.
• the lubricating grease composition (perfluoropolyether oil: 80 wt. %, lithium azelate: 15 wt. %, and PTFE: 5 wt. %) of Example 15 of Patent Document 6 has a abrasion scar diameter of 0.9 mm. This value is inferior to the abrasion scar diameter (0.6 mm) of grease compositions of Comparative Examples 2 and 3 of the present specification, described later (poly- ⁇ -olefin oil containing a 12-hydroxystearic acid lithium soap or a lithium complex soap of azelaic acid and 12-hydroxystearic acid: 80 wt.
• grease compositions of Examples of the present invention have a abrasion scar diameter of 0.4 to 0.8 mm, showing further improved abrasion resistance. Additionally, the expensive fluorine-based base oil is partially substituted by the non-fluorine-based base oil, leading to effective cost reduction.
• the non-fluorine-based base oil is at least one of, for example, synthetic hydrocarbon oils such as poly- ⁇ -olefin, ethylene- ⁇ -olefin oligomer, polybutene or hydrogenates thereof, alkyl benzene, and alkyl naphthalene; ether-based synthetic oils such as polyalkylene glycol, polyphenyl ether, and alkyl-substituted diphenyl ether; ester-based synthetic oils such as trimellitic acid ester, pyromellitic acid ester, neopentyl glycol ester, trimethylolpropane ester, pentaerythritol ester, and dipentaerythritol ester; synthetic oils such as polyol ester, aromatic polycarboxylic acid ester, aliphatic dibasic acid ester, phosphoric acid ester, phosphorous acid ester, and carbonic acid ester; paraffinic mineral oil, naphthenic mineral oil or purified
• non-fluorine-based base oils those having a kinematic viscosity at 40° C. (according to JIS K2283 corresponding to ASTM D445) of about 5 to 1,500 mm 2 /sec., preferably about 10 to 500 mm 2 /sec., are generally used.
• Non-fluorine-based base oils having a kinematic viscosity of less than this range are largely evaporated, and do not comply with the requirements for the standard of JIS ball-and-roller bearing grease, class 3 specified as heat-resistant grease (i.e., the amount of evaporation is 1.5% or less).
• non-fluorine-based base oils having a kinematic viscosity of more than this range have a pour point (according to JIS K2283) of 10° C. or more; bearings cannot be rotated by an ordinary method at the time of low-temperature starting; and they must be heated to make them usable.
• a pour point according to JIS K2283
• fluorine-based base oils those having a kinematic viscosity at 40° C. (according to JIS K2283) of about 10 to 1,500 mm 2 /sec., preferably about 20 to 500 mm 2 /sec., are generally used. More specifically, those represented by the general formula:
• Rf is perfluoromethyl, perfluoroethyl, perfluoropropyl, or other perfluoro lower alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms.
• m+n is 3 to 200
• m:n is 10:90 to 90:10
• CF 2 CF 2 O group and CF 2 O group are randomly bonded to the main chain. This can be obtained by complete fluorination of a precursor produced by photooxidation polymerization of tetrafluoroethylene.
• m+n is 3 to 200
• m:n is 10:90 to 90:10
• CF(CF 3 )CF 2 O group and CF 2 O group are randomly bonded to the main chain. This can be obtained by complete fluorination of a precursor produced by photooxidation polymerization of hexafluoropropylene.
• p+q+r is 3 to 200
• q and r may be 0, (q+r)/p is 0 to 2
• CF(CF 3 )CF 2 O, CF 2 CF 2 O group and CF 2 O group are randomly bonded to the main chain. This can be obtained by complete fluorination of a precursor produced by photooxidation polymerization of hexafluoropropylene and tetrafluoroethylene.
• s+t is 2 to 200
• t may be 0, t/s is 0 to 2
• CF(CF 3 )CF 2 O group and CF 2 CF 2 O group are randomly bonded to the main chain.
• This can be obtained by complete fluorination of a precursor produced by photooxidation polymerization of hexafluoropropylene and tetrafluoroethylene.
• it can be obtained by anionic polymerization of hexafluoropropylene oxide or tetrafluoroethylene oxide in the presence of a cesium fluoride catalyst, and then by fluorine gas treatment of the obtained acid fluoride compound having a terminal —CF(CF 3 )COF group.
• the non-fluorine-based base oil and fluorine-based base oil are used in such a proportion that the former base oil is generally used at a ratio of about 5 to 95 wt. %, preferably about 10 to 90 wt. %, with respect to about 95 to 5 wt. %, preferably about 90 to 10 wt. %, of the latter base oil.
• the proportion of the non-fluorine-based base oil is less than this range, load resistance increases, while abrasion resistance, heat resistance, shear stability, etc. decrease. Conversely, when the proportion is higher than this range, abrasion resistance increases, while heat resistance, load resistance, shear stability, etc. decrease.
• the complex metal soap used as a thickener is formed as a complex metal soap of aliphatic dicarboxylic acid and monoamide monocarboxylic acid.
• the formation of the complex metal soap is carried out during preparation of the lubricating grease composition, as described later.
• saturated or unsaturated dicarboxylic acids having 2 to 20 carbon atoms are used.
• saturated dicarboxylic acids include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonamethylenedicarboxylic acid, decamethylenedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tridecanedicarboxylic acid, tetradecanedicarboxylic acid, pentadecanedicarboxylic acid, hexadecanedicarboxylic acid, heptadecanedicarboxylic acid, octadecanedicarboxylic acid, etc.
• adipic acid Preferably used are adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonamethylenedicarboxylic acid, decamethylenedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tridecanedicarboxylic acid, tetradecanedicarboxylic acid, pentadecanedicarboxylic acid, hexadecanedicarboxylic acid, heptadecanedicarboxylic acid, octadecanedicarboxylic acid, etc.
• unsaturated dicarboxylic acids examples include maleic acid, fumaric acid, 2-methylenesuccinic acid, 2-ethylenesuccinic acid, 2-methyleneglutaric acid, and other alkenyl succinic acids. These saturated or unsaturated dicarboxylic acids are used singly or in combination of two or more.
• Monoamide monocarboxylic acids are obtained by amidation of the monocarboxylic groups of the above dicarboxylic acids.
• amines to be amidated include aliphatic primary amines, such as butylamine, amylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, laurylamine, myristylamine, palmitylamine, stearylamine, and behenylamine; aliphatic secondary amines, such as dipropylamine, diisopropylamine, dibutylamine, diamylamine, dilaurylamine, monomethyl laurylamine, distearylamine, monomethyl stearylamine, dimyristylamine, and dipalmitylamine; aliphatic unsaturated amines, such as allylamine, diallylamine, oleylamine, and dioleylamine; alicyclic amines, such as cycl
• Preferably used are hexylamine, heptylamine, octylamine, nonylamine, decylamine, laurylamine, myristylamine, palmitylamine, stearylamine, behenylamine, dibutylamine, diamylamine, monomethyl laurylamine, monomethyl stearylamine, oleylamine, etc.
• aliphatic dicarboxylic acids and monoamide monocarboxylic acids are used to form complex metal soaps together with lithium, sodium, potassium, calcium, barium, magnesium, copper, iron, cobalt, zinc, aluminum, and other metals; complex barium soaps are preferred.
• examples of the fluororesin powder include PTFE powder, HFP powder, perfluoroalkylene resin powder, etc.
• the fluororesin powder generally has an average primary particle size of about 500 ⁇ m or less, preferably about 0.1 to 30 ⁇ m.
• tetrafluoroethylene is subjected to emulsion polymerization, suspension polymerization, solution polymerization, or like method to produce polytetrafluoroethylene, and the resulting polytetrafluoroethylene is treated by pyrolysis, degradation by electron-beam irradiation, physical pulverization, or like method, so that the number average molecular weight Mn is about 1,000 to 1,000,000.
• the copolymerization of tetrafluoroethylene and hexafluoropropene and the reduction of molecular weight are carried out in the same manner as with polytetrafluoroethylene, so that the number average molecular weight Mn is about 1,000 to 600,000.
• the molecular weight can be controlled by a chain transfer agent during copolymerization reaction.
• a non-fluorine-based base oil, aliphatic dicarboxylic acid, and monoamide monocarboxylic acid are placed in a reaction kettle that allows stirring under heating, and the mixture is stirred while heating to about 80 to 180° C., at which stirring is possible, the reaction is efficiently promoted, and the base oil does not deteriorate.
• metal hydroxide is added to form a complex metal soap in the non-fluorine-based base oil.
• a predetermined amount of amine-based antioxidant, etc. is added thereto, and the mixture is kneaded through a three-roll mill or a high-pressure homogenizer, thereby preparing a non-fluorine-based grease.
• non-fluorine-based base oils other than the non-fluorine-based base oil initially used may be added.
• a fluorine-based base oil and a fluororesin powder are mixed in a mixing kettle, and the mixture is then kneaded through a three-roll mill or a high-pressure homogenizer, thereby preparing a fluorine-based grease.
• the lubricating grease composition of the present invention can be prepared by mixing two kinds of greases, i.e., a non-fluorine-based grease that is a complex metal soap thickener-containing non-fluorine-based base oil, and a fluorine-based grease that is a fluororesin powder-containing fluorine-based base oil.
• the lubricating grease composition of the present invention can also be prepared by adding a fluorine-based base oil and fluororesin to the non-fluorine-based grease prepared in the above manner, and mixing them in a mixing kettle, followed by kneading with a three-roll mill.
• the non-fluorine-based base oil is used in an amount of about 5 to 90 wt. %, preferably about 10 to 80 wt. %, in the base grease;
• the fluorine-based base oil which is used together with the non-fluorine-based base oil at the above-described ratio, is used in an amount of about 5 to 90 wt. %, preferably about 10 to 80 wt. %, in the base grease;
• the complex metal soap is used in an amount of about 1.5 to 30 wt. %, preferably about 5 to 25 wt. %, in the base grease;
• the fluororesin powder is used in an amount of about 0.1 to 50 wt. %, preferably about 5 to 35 wt. %, in the base grease.
• Non-fluorine-based base oil thickeners having little or no compatibility with the fluorine-based base oil can be added, thereby resulting in increased abrasion resistance, lower friction coefficient, and improved rust prevention and corrosion inhibition effect.
• Fluorine-based base oil heat resistance is improved.
• Fluororesin powder the compatibility between the fluorine-based base oil and the complex metal soap increases.
• the lubricating grease composition may contain, if necessary, antioxidants, rust inhibitors, corrosion inhibitors, extreme pressure additives, oiliness agents, solid lubricants, and other additives used in conventional lubricants.
• antioxidants include phenol-based antioxidants, such as 2,6-di-tert-butyl-4-methylphenol and 4,4′-methylenebis(2,6-di-tert-butylphenol); amine-based antioxidants, such as alkyl diphenylamine having a C 4 -C 20 alkyl group, triphenylamine, phenyl- ⁇ -naphthylamine, alkylated phenyl- ⁇ -naphthylamine, phenothiazine, and alkylated phenothiazine; phosphoric acid-based antioxidants, sulfur-based antioxidants, and the like.
• rust inhibitors include fatty acids, fatty acid metal salts, fatty acid amines, alkylsulfonic acid metal salts, alkylsulfonic acid amine salts, oxided paraffin, polyoxyethylene alkyl ethers, and the like.
• corrosion inhibitors include benzotriazole, benzoimidazole, thiadiazole, and the like.
• extreme pressure additives include phosphorus-based compounds, such as phosphoric acid esters, phosphorous acid esters, and phosphoric acid ester amine salts; sulfur-based compounds, such as sulfides and disulfides; sulfur-based compound metal salts, such as dialkyldithiophosphoric acid metal salts and dialkyldithiocarbamic acid metal salts; chlorine-based compounds, such as chlorinated paraffin and chlorinated diphenyl; and the like.
• phosphorus-based compounds such as phosphoric acid esters, phosphorous acid esters, and phosphoric acid ester amine salts
• sulfur-based compounds such as sulfides and disulfides
• sulfur-based compound metal salts such as dialkyldithiophosphoric acid metal salts and dialkyldithiocarbamic acid metal salts
• chlorine-based compounds such as chlorinated paraffin and chlorinated diphenyl; and the like.
• oiliness agents include fatty acids or esters thereof, higher alcohols, polyhydric alcohols or esters thereof, aliphatic esters, aliphatic amines, fatty acid monoglycerides, montan wax, amide-based wax, and the like.
• oiliness agents include fatty acids or esters thereof, higher alcohols, polyhydric alcohols or esters thereof, aliphatic esters, aliphatic amines, fatty acid monoglycerides, montan wax, amide-based wax, and the like.
• other solid lubricants include molybdenum disulfide, graphite, boron nitride, silane nitride, melamine cyanurate, and the like. Such other solid lubricants have an average primary particle size of 30 ⁇ m or less, preferably 0.1 to 20 ⁇ m.
• thickeners that have generally been used as thickeners, such as silica, clay, graphite, zinc oxide, urea compounds, polyethylene, polypropylene, polyamide, organic pigments, metal soaps, etc., can be suitably added.
• a lithium soap of 12-hydroxystearic acid accounting for 10 wt. % of the base grease as a thickener, was synthesized.
• 2 wt. % of amine-based antioxidant NA-LUBE AO-120 was added, and the mixture was kneaded twice by a three-roll mill, thereby producing a grease D.
• a lithium complex soap of azelaic acid and 12-hydroxystearic acid accounting for 20 wt. % of the base grease as a thickener, was synthesized.
• 3 wt. % of oiliness agent trimethylolpropane alkyl ester; 40° C. viscosity: 30 mm 2 /sec.
• 2 wt. % of amine-based antioxidant NA-LUBE AO-120
• a fluorine-based base oil (40° C. viscosity: 230 mm 2 /sec.) having a molecular structure represented by the general formula: RfO[CF(CF 3 )CF 2 O] m Rf was mixed with a PTFE powder (average particle diameter: 0.3 ⁇ m) in an amount accounting for 32 wt. % of the base grease. The mixture was kneaded twice by a three-roll mill, thereby producing a grease I.
• a fluorine-based base oil (40° C. viscosity: 230 mm 2 /sec.) having a molecular structure represented by the general formula: RfO[CF(CF 3 )CF 2 O] m Rf was mixed with a PTFE powder (average particle diameter: 0.3 ⁇ m) in an amount accounting for 18 wt. % of the base grease. The mixture was kneaded twice by a three-roll mill, thereby producing a grease II.
• a fluorine-based base oil (40° C. viscosity: 85 mm 2 /sec.) having a molecular structure represented by the general formula: RfO(CF 2 CF 2 O) m (CF 2 O) n Rf was mixed with a PTFE powder (average particle diameter: 0.3 ⁇ m) in an amount accounting for 27 wt. % of the base grease. The mixture was kneaded twice by a three-roll mill, thereby producing a grease III.
• One or two kinds of the non-fluorine-based greases A to E and the fluorine-based greases I and II prepared in the above Reference Examples were mixed at predetermined weight ratios. Each of the resulting mixtures was sufficiently stirred in a mixing kettle, and then kneaded twice by a three-roll mill, thereby producing lubricating grease compositions.
• the produced lubricating grease compositions were measured for the following items:
• Abrasion resistance Shell four-ball test, according to ASTM D2266
• the lubricating grease composition of the present invention which has excellent characteristics as described above, i.e., excellent heat resistance, shear stability, abrasion resistance to mating materials, and load resistance, as well as satisfies the cost requirements, can be suitably used to lubricate and protect the contact portion between individual sliding parts of ball-and-roller bearings, sliding bearings, sintering bearings, gears, valves, cocks, oil seals, electric contacts, etc.
• the lubricating grease composition can be suitably applied in various parts of various devices, machines, and apparatuses listed below.

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