JP2005239898A - Grease composition for constant velocity joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grease composition for constant velocity joints which achieves flaking resistance, seizure resistance and wear resistance at a high level in a good balance without using a lead compound and satisfactorily maintains these properties for a long period of time. <P>SOLUTION: The grease composition for constant velocity joints includes a base oil for a lubricating oil, a thickener, carbon black with an average particle size of ≤500 nm and an organic molybdenium compound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a grease composition for a constant velocity joint.

  A constant velocity joint is a joint used for applications such as a driving force transmission shaft from an automobile mission to a tire. The types of constant velocity joints include fixed constant velocity joints such as barfield joints, zeppa joints, and undercut free joints, and slide type constant velocity joints such as double offset joints, tripod joints, and cross groove joints.

Constant velocity joints are required to have performances such as flaking resistance, seizure resistance, wear resistance, and low friction. Therefore, in order to ensure these performances, as grease for constant velocity joints, additives such as molybdenum disulfide and lead compounds are blended with base grease consisting of lubricating base oil, lithium soap and urea-based thickener. Are mainly used (see, for example, Patent Documents 1 and 2).
Japanese Patent Laid-Open No. 04-304300 Japanese Patent Laid-Open No. 06-57283

  In recent years, the load applied to a constant velocity joint is increasing as the performance and size and weight of automobiles are increased. However, the above-mentioned conventional grease is not necessarily sufficient in terms of flaking resistance, seizure resistance, wear resistance, low friction, etc., and high performance and long life in constant velocity joints with heavy loads. There is room for improvement to achieve this.

  Further, as described above, lead compounds are sometimes used as additives in conventional greases, but it is desirable that lead compounds be not used as much as possible from the viewpoint of safety to the human body and the environment.

  The present invention has been made in view of such circumstances, and without using a lead compound, it can achieve a high level of anti-flaking, seizure and wear resistance in a balanced manner, and It is an object of the present invention to provide a grease composition for a constant velocity joint that can sufficiently maintain these characteristics over a long period of time.

  In order to solve the above problems, the grease composition for constant velocity joints of the present invention comprises a lubricating base oil, a thickener, carbon black having an average particle size of 500 nm or less, and an organic molybdenum compound. It is characterized by that.

  In this way, the above-mentioned specific carbon black and organomolybdenum compound are added to the lubricant base oil together with a thickener to achieve all of anti-flaking, seizure and wear resistance in a well-balanced manner. Moreover, those characteristics can be sufficiently maintained over a long period of time. Therefore, according to the grease composition for a constant velocity joint of the present invention, it is possible to effectively realize high performance and long life of the constant velocity joint without using a lead compound.

  The grease composition for constant velocity joints of the present invention preferably further contains at least one selected from a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and a zinc-based extreme pressure agent. As a result, the flaking resistance, seizure resistance, and wear resistance can be further improved.

  The grease composition for constant velocity joints of the present invention is a complex of a fatty acid salt and a carbonate, wherein the fatty acid is overbased with a carbonate, and at least one selected from organic acid salts. It is preferable to further contain. Thereby, flaking resistance and seizure resistance can be further improved.

  According to the present invention, flaking resistance, seizure resistance and abrasion resistance can be achieved at a high level and well balanced without using lead compounds, and these characteristics can be sufficiently maintained over a long period of time. A grease composition for a constant velocity joint is provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  Examples of the lubricating base oil of the grease composition for constant velocity joints of the present invention include mineral oil and / or synthetic oil. As mineral oil, a mineral oil obtained by a method usually used in a lubricating oil production process in the petroleum refining industry, more specifically, a lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil is subjected to solvent removal. Mineral oil refined by one or more treatments such as rubble, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, clay treatment, and the like.

  Specific examples of synthetic oils include poly α-olefins such as polybutene, 1-octene oligomer, 1-decene oligomer, or hydrides thereof; ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditrile. Diesters such as decyl adipate and di3-ethylhexyl sebacate; polyol esters such as trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate; alkyl naphthalene; alkylbenzene, polyoxy Polyalkylethers; dialkyldiphenyl ethers; silicone oils; or mixtures thereof.

Kinematic viscosity at 100 ° C. of the lubricating base oil is preferably 2 to 40 mm ² / s, more preferably 3 to 20 mm ² / s. The viscosity index of the lubricating base oil is preferably 90 or higher, more preferably 100 or higher.

  Thickeners include soap-type thickeners such as metal soaps and composite metal soaps, benton, silica gel, and urea-type thickeners (urea compounds, urea / urethane compounds, urethane compounds, etc.). Any thickening agent such as an agent can be used. From the viewpoint of heat resistance, a urea compound, a urea / urethane compound, a urethane compound or a mixture thereof is preferable.

  Specific examples of the soap-based thickener include sodium soap, calcium soap, aluminum soap, lithium soap and the like.

  Examples of the urea-based thickener include urea compounds such as diurea compounds, triurea compounds, tetraurea compounds, and polyurea compounds (excluding diurea compounds, triurea compounds, and tetraurea compounds), and urethanes such as urea / urethane compounds and diurethane compounds. Examples thereof include a compound or a mixture thereof, and among them, a diurea compound, a urea / urethane compound, a diurethane compound or a mixture thereof is preferable.

  Preferable examples of the urea thickener include compounds represented by the following general formula (1). The compound represented by the general formula (1) includes a diurea compound, a urea / urethane compound, and a diurethane compound.

A-CONH-R ¹ -NHCO-B (1)
In general formula (1), R ¹ represents a divalent organic group, preferably a divalent hydrocarbon group. Specific examples of the divalent hydrocarbon group include a linear or branched alkylene group, a linear or branched alkenylene group, a cycloalkylene group, an arylene group, an alkylarylene group, and an arylalkylene group. Is mentioned. The carbon number of the divalent organic group represented by R ¹ is preferably 6 to 20, and more preferably 6 to 15.

Preferable examples of the divalent organic group represented by R ¹ include an ethylene group, a 2,2-dimethyl-4-methylhexylene group, and groups represented by the following formulas (2) to (11). Among them, the groups represented by the formulas (3) and (5) are preferable.

In general formula (1), A and B may be the same or different and each represents a group represented by —NHR ² , —NR ³ R ⁴ or —OR ⁵ . Here, R ² , R ³ , R ⁴ and R ⁵ may be the same or different and each is a monovalent organic group, preferably a monovalent hydrocarbon group having 6 to 20 carbon atoms.

Examples of the monovalent hydrocarbon group having 6 to 20 carbon atoms represented by R ² , R ³ , R ⁴ and R ⁵ include a linear or branched alkyl group, a linear or branched alkenyl group. Group, cycloalkyl group, alkylcycloalkyl group, aryl group, alkylaryl group, arylalkyl group and the like. More specifically, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl Linear or branched alkyl groups such as: hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, nonadecenyl Straight chain or branched alkenyl groups such as eicocenyl group; cyclohexyl group; methylcyclohexyl group, dimethylcyclohexyl group, ethylcyclohexyl group, diethylcyclohexyl group, propylcyclohexyl group, isopropylcyclohexyl group Sil group, 1-methyl-3-propyl cyclohexyl group, butyl cyclohexyl group, amyl cyclohexyl group, amyl methyl cyclohexyl group, hexyl cyclohexyl group, heptyl cyclohexyl group, octyl cyclohexyl group, nonyl cyclohexyl group, decyl cyclohexyl group, undecyl cyclohexyl group Alkylcycloalkyl groups such as dodecylcyclohexyl group, tridecylcyclohexyl group and tetradecylcyclohexyl group; aryl groups such as phenyl group and naphthyl group; toluyl group, ethylphenyl group, xylyl group, propylphenyl group, cumenyl group and methylnaphthyl group Alkylaryl groups such as ethyl naphthyl group, dimethyl naphthyl group and propyl naphthyl group; aryls such as benzyl group, methylbenzyl group and ethylbenzyl group Alkyl group, etc. Among these, from the viewpoint of heat resistance and acoustic anti-, alkyl group, cycloalkyl group, alkylcycloalkyl group, an aryl group and an alkylaryl group.

The compound represented by the general formula (1) is, for example, a diisocyanate represented by OCN-R ¹ -NCO, a compound represented by R ² NH ₂ , R ³ R ⁴ NH, or R ⁵ OH, or a mixture thereof. Is reacted in a base oil at 10 to 200 ° C. Note that R ¹ , R ² , R ³ , R ⁴ , and R ⁵ in the formula representing the raw material compound are R ¹ , R ² , R ³ , R ⁴ , and R ⁵ as synonymous.

Among the compounds represented by the general formula (1), from the viewpoint of heat resistance, compounds in which A and B in the formula are —NHR ^2, that is, compounds represented by the following general formula (12) are particularly preferable. Here, in the general formula (12), R ¹ represents a divalent organic group, and R ² represents a monovalent organic group, and is equivalent to R ¹ and R ² described above.

  The content of the thickener is preferably 2% by mass or more, more preferably 5% by mass or more, based on the total amount of the composition. When the content of the thickener is less than 2% by mass, the effect of adding the thickener becomes insufficient, and it becomes difficult to make the grease composition sufficiently greasy. The content of the thickener is preferably 30% by mass or less, more preferably 20% by mass or less, based on the total amount of the composition. When the content of the thickener exceeds 30% by mass, the grease composition becomes excessively hard and it becomes difficult to obtain sufficient lubrication performance.

  The grease composition for constant velocity joints of the present invention contains carbon black having an average particle size of 500 nm or less and an organic molybdenum compound as essential components in addition to the above-described lubricating base oil and thickener.

  Here, the carbon black means a diameter of 3 to 500 nm obtained by instantaneous carbonization of raw material hydrocarbons (oil, gas, etc.) at a high temperature (for example, 300 to 1800 ° C., preferably 800 to 1800 ° C.) for several ms. This means black particles of a degree and is distinguished from graphite. For example, the graphite crystal structure is hexagonal hexagonal plate-like flat (or trigonal polymorph), whereas carbon black is a kind of amorphous carbon with a complex collection of microcrystals. Consisting of a certain unit particle, the microcrystal has a turbulent layer structure in which several layers of aromatic planar molecules having an average diameter of 20 to 30 mm are gathered. Further, the carbon black unit particles are linked together to form an aggregate (structure), and an acidic functional group or the like may exist on the surface of the particles. If graphite is used instead of carbon black, the flaking resistance, seizure resistance and wear resistance are insufficient.

  As described above, the average particle size of the carbon black used in the present invention is 500 nm or less, preferably 100 nm or less. When the average particle diameter of carbon black exceeds 500 nm, the flaking resistance, seizure resistance and wear resistance are insufficient. Further, the lower limit of the average particle diameter is not particularly limited, but those having a size of usually 10 nm or more, preferably 15 nm or more are used from the viewpoints of manufacturability and availability. In addition, the average particle diameter here is an average particle diameter (average diameter) of the unit particles of carbon black described above, and means an average value measured by an electron microscope.

  The method for producing carbon black used in the present invention is not particularly limited as long as the average particle diameter is within the above range. Typical manufacturing methods include furnace method, acetylene method, lamp method, thermal method, channel method and the like.

  The content of carbon black is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, based on the total amount of the composition. If the carbon black content is less than the lower limit, the effect of improving the flaking resistance, seizure resistance and wear resistance due to the addition of carbon black tends to be insufficient. The content of carbon black is preferably 15% by mass or less, more preferably 10% by mass or less, based on the total amount of the composition. Even if the content of the carbon black exceeds the above upper limit, there is a tendency that the effect of improving the flaking resistance, seizure resistance and wear resistance commensurate with the content cannot be obtained.

  Examples of the organomolybdenum compound used in the present invention include phosphoric acid or thiophosphoric acid ester derivatives represented by the following general formula (13) and dithiocarbamic acid ester derivatives represented by the following general formula (14). It is done.

In the general formulas (13) and (14), R ⁶ may be the same or different, each represents a hydrocarbon group having 1 or more carbon atoms, X may be the same or different, and each represents an oxygen atom or sulfur. Represents an atom, and a, b and c each represents an integer of 1 to 6;

Examples of the hydrocarbon group represented by R ⁶ in the general formulas (13) and (14) include an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, and a carbon group having 6 to 11 carbon atoms. Examples thereof include an alkylcycloalkyl group, an aryl group having 6 to 18 carbon atoms, an alkylaryl group having 7 to 24 carbon atoms, and an arylalkyl group having 7 to 12 carbon atoms.

  Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group (including all branched isomers), a butyl group (including all branched isomers), and a pentyl group (all branched isomers). Isomers), hexyl groups (including all branched isomers), heptyl groups (including all branched isomers), octyl groups (including all branched isomers), nonyl groups (all Including branched isomers), decyl group (including all branched isomers), undecyl group (including all branched isomers), dodecyl group (including all branched isomers), tridecyl group (including All branched isomers), tetradecyl group (including all branched isomers), pentadecyl group (including all branched isomers), hexadecyl group (including all branched isomers), heptadecyl Groups (including all branched isomers), octadecyl groups (all branches) Nonadecyl group (including all branched isomers), icosyl group (including all branched isomers), heicosyl group (including all branched isomers), docosyl group (all A branched isomer), a tricosyl group (including all branched isomers), a tetracosyl group (including all branched isomers), and the like.

  Specific examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.

  Specific examples of the alkylcycloalkyl group include a methylcyclopentyl group (including all substituted isomers), an ethylcyclopentyl group (including all substituted isomers), and a dimethylcyclopentyl group (including all substituted isomers). ), Propylcyclopentyl group (including all branched isomers and substituted isomers), methylethylcyclopentyl group (including all substituted isomers), trimethylcyclopentyl group (including all substituted isomers), butylcyclopentyl group (Including all branched isomers and substituted isomers), methylpropylcyclopentyl group (including all branched isomers and substituted isomers), diethylcyclopentyl group (including all substituted isomers), dimethylethylcyclopentyl Group (including all substituted isomers), methylcyclohexyl group (including all substituted isomers) Ethylcyclohexyl group (including all substituted isomers), dimethylcyclohexyl group (including all substituted isomers), propylcyclohexyl group (including all branched isomers and substituted isomers), methylethylcyclohexyl group (all ), Trimethylcyclohexyl group (including all substituted isomers), butylcyclohexyl group (including all branched isomers and substituted isomers), methylpropylcyclohexyl group (including all branched isomers) , Including substituted isomers), diethylcyclohexyl group (including all substituted isomers), dimethylethylcyclohexyl group (including all substituted isomers), methylcycloheptyl group (including all substituted isomers), ethyl Cycloheptyl group (including all substituted isomers), dimethylcycloheptyl group (including all substituted isomers) ), Propylcycloheptyl group (including all branched isomers and substituted isomers), methylethylcycloheptyl group (including all substituted isomers), trimethylcycloheptyl group (including all substituted isomers), Butylcycloheptyl group (including all branched and substituted isomers), methylpropylcycloheptyl group (including all branched and substituted isomers), diethylcycloheptyl group (including all substituted isomers) And dimethylethylcycloheptyl group (including all substituted isomers) and the like.

  Specific examples of the aryl group include a phenyl group and a naphthyl group.

  Specific examples of the alkylaryl group include tolyl groups (including all substituted isomers), xylyl groups (including all substituted isomers), ethylphenyl groups (including all substituted isomers), propyl Phenyl group (including all branched isomers, substituted isomers), methylethylphenyl group (including all substituted isomers), trimethylphenyl group (including all substituted isomers), butylphenyl group (all Branched isomers, including substituted isomers), methylpropylphenyl group (including all branched isomers and substituted isomers), diethylphenyl group (including all substituted isomers), dimethylethylphenyl group (all ), Pentylphenyl group (including all branched isomers, including substituted isomers), hexylphenyl group (including all branched isomers, including substituted isomers), heptylpheny Group (including all branched isomers and substituted isomers), octylphenyl group (including all branched isomers and substituted isomers), nonylphenyl group (including all branched isomers and substituted isomers) ), Decylphenyl group (including all branched isomers and substituted isomers), undecylphenyl group (including all branched isomers and substituted isomers), dodecylphenyl group (all branched isomers, Substituted isomers), tridecylphenyl group (including all branched isomers and substituted isomers), tetradecylphenyl group (including all branched isomers and substituted isomers), pentadecylphenyl group (including All branched isomers, including substituted isomers), hexadecylphenyl group (including all branched isomers and substituted isomers), heptadecylphenyl group (including all branched isomers, substituted isomers) ), Octadecylphenyl group (all Branched isomers and substituted isomers thereof), and the like.

  Examples of the arylalkyl group include a benzyl group, a phenethyl group, a phenylpropyl group (including all branched isomers), a phenylbutyl group (including all branched isomers), and the like.

  Specific examples of the compounds represented by the general formulas (13) and (14) include molybdenum phosphate, molybdenum thiophosphate, molybdenum dithiophosphate, molybdenum dithiocarbamate, and the like.

  The phosphoric acid or thiophosphoric acid ester derivative represented by the above general formula (13) and the dithiocarbamic acid ester derivative represented by the following general formula (14) are usually phosphoric acid ester, thiophosphoric acid ester, dithiocarbamic acid ester and It is a compound obtained by reacting an inorganic molybdenum compound (such as molybdenum trioxide, molybdic acid or a salt thereof) together with a sulfur source as necessary.

  In addition, since molybdenum can take various valences, the compound obtained by the above reaction is usually a mixture. Among these, the most typical compounds include compounds represented by the following formulas (15) and (16).

(R ⁶ and X in the formulas (15) and (16) have the same definition as R ⁶ and X in the formula (13), respectively.)
In the present invention, as the organic molybdenum compound, only one of the compounds represented by the general formulas (13) and (14) may be used, or both may be used in combination. From the viewpoint of stability, it is preferable to use the compound represented by the general formula (14). The content of the organomolybdenum compound is preferably 0.1% by mass or more, more preferably 0.8% by mass based on the total amount of the composition. It is 5 mass% or more. When the content of the organomolybdenum compound is less than 0.1% by mass, the grease does not have sufficient anti-flaking, seizure and wear resistance; the upper limit is 20% by mass, preferably 10% by mass . On the other hand, when the amount exceeds 20% by mass, flaking resistance, seizure resistance, and wear resistance sufficient to meet the addition amount cannot be obtained.

  The grease composition for constant velocity joints of the present invention may comprise the above lubricating base oil, a thickener, carbon black having an average particle size of 500 nm or less, and an organic molybdenum compound. It is preferable to further contain at least one selected from a pressure agent, a phosphorus extreme pressure agent and a zinc extreme pressure agent.

  Examples of the sulfur extreme pressure agent include dihydrocarbyl polysulfide, sulfide ester, sulfide mineral oil, thiazole compound, and thiadiazole compound.

  Dihydrocarbyl polysulfide is a sulfur compound generally referred to as polysulfide or sulfurized olefin, and is specifically represented by the following general formula (17).

_{^{R 7 -S x -R 8 (17}} )
In the general formula (17), R ⁷ and R ⁸ may be the same or different, and are each a linear or branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, carbon An alkylaryl group having 6 to 20 carbon atoms or an arylalkyl group having 6 to 20 carbon atoms is represented, and x represents an integer of 2 to 6, preferably 2 to 5.

Specific examples of the alkyl group represented by R ⁷ and R ⁸ include n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, straight chain or Branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, linear or branched undecyl Group, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched hexadecyl group, linear or branched heptadecyl group, Examples thereof include a linear or branched octadecyl group, a linear or branched nonadecyl group, and a linear or branched icosyl group.

Specific examples of the aryl group represented by R ⁷ and R ⁸ include a phenyl group and a naphthyl group.

Specific examples of the alkylaryl group represented by R ⁷ and R ⁸ include a tolyl group (including all structural isomers), an ethylphenyl group (including all structural isomers), straight-chain or branched Propylphenyl group (including all structural isomers), straight chain or branched butylphenyl group (including all structural isomers), straight chain or branched pentylphenyl group (including all structural isomers), straight Chain or branched hexylphenyl group (including all structural isomers), linear or branched heptylphenyl group (including all structural isomers), linear or branched octylphenyl group (including all structural isomers) Straight chain or branched nonylphenyl group (including all structural isomers), straight chain or branched decylphenyl group (including all structural isomers), straight chain or branched undecylphenyl group (all A straight chain) Is a branched dodecylphenyl group (including all structural isomers), xylyl group (including all structural isomers), ethylmethylphenyl group (including all structural isomers), diethylphenyl group (all structural isomers) ), Di (straight or branched) propylphenyl group (including all structural isomers), di (straight or branched) butylphenyl group (including all structural isomers), methyl naphthyl group (Including all structural isomers), ethyl naphthyl group (including all structural isomers), linear or branched propyl naphthyl group (including all structural isomers), linear or branched butyl naphthyl group (including all structural isomers) Including all structural isomers), dimethylnaphthyl group (including all structural isomers), ethylmethylnaphthyl group (including all structural isomers), diethylnaphthyl group (including all structural isomers), di (Straight or straight May include a branched) propyl naphthyl group (including all structural isomers), a di (straight or branched) butyl naphthyl group (including all structural isomers), and the like.

Specific examples of the arylalkyl group represented by R ⁷ and R ⁸ include a benzyl group, a phenylethyl group (including all isomers), a phenylpropyl group (including all isomers), and the like. Can do.

R ⁷ and R ⁸ are each an alkyl group having 3 to 18 carbon atoms, an aryl group having 6 to 8 carbon atoms, an alkylaryl group having 7 to 8 carbon atoms, or a carbon number derived from propylene, 1-butene or isobutylene. It is preferably a 7-8 arylalkyl group.

  Specifically, preferred alkyl groups include isopropyl groups, branched hexyl groups derived from propylene dimers (including all branched isomers), and branched forms derived from propylene trimers. Nonyl group (including all branched isomers), branched dodecyl group derived from propylene tetramer (including all branched isomers), branched structure derived from propylene pentamer Pentadecyl group (including all branched isomers), branched octadecyl group (including all branched isomers) derived from propylene hexamer, sec-butyl group, tert-butyl group, 1 -Branched octyl group derived from butene dimer (including all branched isomers), Branched octyl group derived from isobutylene dimer (including all branched isomers) , A fraction derived from 1-butene trimer Dodecyl group (including all branched isomers), branched dodecyl group derived from isobutylene trimer (including all branched isomers), derived from 1-butene tetramer Examples include branched hexadecyl groups (including all branched isomers), branched hexadecyl groups (including all branched isomers) derived from isobutylene tetramer, and the like. Moreover, a phenyl group can be mentioned as a preferable aryl group. Preferred alkylaryl groups include tolyl groups (including all structural isomers), ethylphenyl groups (including all structural isomers), xylyl groups (including all structural isomers), and the like. it can. Preferred arylalkyl groups include benzyl and phenethyl groups (including all isomers).

Furthermore, R ⁷ and R ⁸ are more preferably a branched alkyl group having 3 to 18 carbon atoms derived from ethylene or propylene, because they are more excellent in anti-flaking and seizure resistance. it is particularly preferred ethylene or a branched alkyl group having from 6 to 15 carbon atoms derived from propylene.

  Moreover, as dihydrocarbyl polysulfide, those having an arbitrary sulfur content can be used, but from the viewpoint of anti-flaking and seizure resistance, the sulfur content is usually 10 to 55% by mass, preferably 20 to 20%. It is preferable to use 50% by mass.

  Specific examples of the sulfur ester include animal and vegetable fats and oils such as beef tallow, pork tallow, fish tallow, rapeseed oil and soybean oil; unsaturated fatty acids (oleic acid, linoleic acid or fatty acids extracted from the above-mentioned animal and plant fats and the like) And an unsaturated fatty acid ester obtained by reacting various alcohols with each other; and a mixture thereof obtained by sulfiding by an arbitrary method.

  Further, as the sulfurized ester, those having an arbitrary sulfur content can be used, but from the viewpoint of anti-flaking and seizure resistance, the sulfur content is usually 2 to 40% by mass, preferably 5 to 35% by mass. It is preferable to use those.

  Sulfided mineral oil refers to one obtained by dissolving elemental sulfur in mineral oil. The mineral oil used in the present invention is not particularly limited, and specific examples include mineral oil-based lubricant base oils mentioned as examples of the above-described lubricant base oil. In addition, as the elemental sulfur, any form such as a lump, powder, or molten liquid may be used, but a powder or molten liquid can be efficiently dissolved in the base oil. Therefore, it is preferable. When using molten liquid elemental sulfur, the liquids are mixed together, so there is an advantage that the melting operation can be performed in a very short time, but it is handled above the melting point of elemental sulfur. In addition, it is not always easy to handle because it requires a special device such as a heating facility and is dangerous because it is handled in a high temperature atmosphere. On the other hand, powdery simple sulfur is particularly preferable because it is inexpensive and easy to handle and has a sufficiently short dissolution time. Moreover, although there is no restriction | limiting in particular in sulfur content in sulfide mineral oil, Preferably it is 0.05-1.0 mass% normally on the basis of the total amount of sulfide mineral oil, More preferably, it is 0.1-0.5 mass%. .

  As the thiazole compound, compounds represented by the following general formulas (18) and (19) are preferably used.

(In the formulas (18) and (19), R ⁹ and R ¹⁰ each represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms or an amino group, and R ¹¹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. D and e represent an integer of 0 to 3]
Among these, the benzothiazole compound represented by the general formula (19) is particularly preferable. Here, R ¹⁰ in the general formula (19) represents a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or an amino group as described above, but R ¹⁰ represents a hydrogen atom or 1 to 1 carbon atom. It is preferably an 18 hydrocarbon group, more preferably a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. Further, R ¹¹ in the general formula (19) is, representing the previously described hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ¹¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms It is preferably a hydrogen atom or a hydrocarbon group having 1 to 2 carbon atoms. Furthermore, e in the general formula (19) represents an integer of 0 to 3 as described above, and e is preferably 0 to 2. Specific examples of such benzothiazole compounds include benzothiazole, 2-mercaptobenzothiazole, 2- (hexyldithio) benzothiazole, 2- (octyldithio) benzothiazole, 2- (decyldithio) benzothiazole, 2- ( Dodecyldithio) benzothiazole, 2- (N, N-diethyldithiocarbamyl) benzothiazole and the like.

  As the thiadiazole compound, a 1,3,4-thiadiazole compound represented by the following general formula (20), a 1,2,4-thiadiazole compound represented by the following general formula (21), and the following general formula (22) A 1,4,5-thiadiazole compound represented by the formula is preferably used.

[In the above formulas (20), (21) and (22), R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ may be the same or different, and each represents a hydrogen atom or a carbon number of 1 to 20 represents a hydrocarbon group, and c, d, e, f, g and h may be the same or different and each represents an integer of 0 to 8]
Here, R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ in the general formulas (20) to (22) are each a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms as described above. R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ are each preferably a hydrogen atom or a hydrocarbon having 1 to 18 carbon atoms. More preferably, it is 12 hydrocarbon groups. In the above general formulas (7) to (9), c, d, e, f, g, and h each represent an integer of 0 to 3 as described above, but c, d, e, f, g and h are each preferably an integer of 0 to 2. Specific examples of such thiadiazole compounds include 2,5-bis (n-hexyldithio) -1,3,4-thiadiazole, 2,5-bis (n-octyldithio) -1,3,4-thiadiazole. 2,5-bis (n-nonyldithio) -1,3,4-thiadiazole, 2,5-bis (1,1,3,3-tetramethylbutyldithio) -1,3,4-thiadiazole, 3, 5-bis (n-hexyldithio) -1,2,4-thiadiazole, 3,5-bis (n-octyldithio) -1,2,4-thiadiazole, 3,5-bis (n-nonyldithio) -1 , 2,4-thiadiazole, 3,5-bis (1,1,3,3-tetramethylbutyldithio) -1,2,4-thiadiazole, 4,5-bis (n-hexyldithio) -1,2 , 3-thiadiazole, 4 5-bis (n-octyldithio) -1,2,3-thiadiazole, 4,5-bis (n-nonyldithio) -1,2,3-thiadiazole, 4,5-bis (1,1,3,3) -Tetramethylbutyldithio) -1,2,3-thiadiazole and the like.

  Among the above, the sulfur-based extreme pressure agent used in the present invention is more preferably dihydrocarbyl polysulfide or sulfide ester from the viewpoint of flaking resistance, seizure resistance, and wear resistance.

  When these sulfur-based extreme pressure agents are included in the grease composition for constant velocity joints of the present invention, the content is not particularly limited, but is preferably 0.05 to 20% by mass, more preferably, based on the composition. It is 0.1-15 mass%, More preferably, it is 0.5-10 mass%.

  The phosphorus additive is preferably at least one selected from phosphoric acid esters, acidic phosphoric acid esters, amine salts of acidic phosphoric acid esters, phosphorous acid esters and phosphorothioates.

  Among the phosphorous additives, phosphoric acid ester, acidic phosphoric acid ester, amine salt of acidic phosphoric acid ester and phosphorous acid ester are phosphoric acid or phosphorous acid and alkanol, an ester of polyether type alcohol or its derivative It is.

Phosphate esters include tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, tridodecyl phosphate, tritridecyl phosphate, tritetradecyl phosphate , Tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, etc .;
Examples of acidic phosphate esters include monobutyl acid phosphate, monopentyl acid phosphate, monohexyl acid phosphate, monoheptyl acid phosphate, monooctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate, monoundecyl acid phosphate, monododecyl Acid phosphate, monotridecyl acid phosphate, monotetradecyl acid phosphate, monopentadecyl acid phosphate, monohexadecyl acid phosphate, monoheptadecyl acid phosphate, monooctadecyl acid phosphate, monooleyl acid phosphate, dibutyl acid phosphate, dipentyl acid , Dihexyl reed Dophosphate, diheptyl acid phosphate, dioctyl acid phosphate, dinonyl acid phosphate, didecyl acid phosphate, diundecyl acid phosphate, didodecyl acid phosphate, ditridecyl acid phosphate, ditetradecyl acid phosphate, dipentadecyl acid, dipentadecyl acid Hexadecyl acid phosphate, diheptadecyl acid phosphate, dioctadecyl acid phosphate, dioleyl acid phosphate, etc .;
Examples of the amine salt of acidic phosphate ester include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, Salts with amines such as dipentylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, etc .;
Examples of the chlorinated phosphate ester include tris-dichloropropyl phosphate, tris-chloroethyl phosphate, tris-chlorophenyl phosphate, polyoxyalkylene bis [di (chloroalkyl)] phosphate, and the like;
As phosphites, dibutyl phosphite, dipentyl phosphite, dihexyl phosphite, diheptyl phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, didodecyl phosphite, dioleyl Phosphite, diphenyl phosphite, dicresyl phosphite, tributyl phosphite, tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, triundecyl phosphite Phyto, tridodecyl phosphite, trioleyl phosphite, triphenyl phosphite, tricresyl phosphite and the like. Mixtures of these can also be used.

  Phosphorothionate is a compound represented by the following general formula (23).

[Wherein R ¹⁸ , R ¹⁹ and R ²⁰ may be the same or different and each represents a hydrocarbon group having 1 to 24 carbon atoms]
Specific examples of the hydrocarbon group having 1 to 24 carbon atoms represented by R ¹⁸ , R ¹⁹ and R ²⁰ include an alkyl group, a cycloalkyl group, an alkenyl group, an alkylcycloalkyl group, an aryl group, an alkylaryl group, An arylalkyl group etc. are mentioned.

  Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group. And alkyl groups such as hexadecyl group, heptadecyl group and octadecyl group (these alkyl groups may be linear or branched).

  As a cycloalkyl group, C5-C7 cycloalkyl groups, such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, can be mentioned, for example. Examples of the alkylcycloalkyl group include a methylcyclopentyl group, a dimethylcyclopentyl group, a methylethylcyclopentyl group, a diethylcyclopentyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a methylethylcyclohexyl group, a diethylcyclohexyl group, a methylcycloheptyl group, Examples thereof include an alkylcycloalkyl group having 6 to 11 carbon atoms such as a dimethylcycloheptyl group, a methylethylcycloheptyl group, and a diethylcycloheptyl group (the substitution position of the alkyl group with the cycloalkyl group is also arbitrary).

  Examples of the alkenyl group include butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl Alkenyl groups such as groups (these alkenyl groups may be linear or branched, and the position of the double bond is also optional).

  As an aryl group, aryl groups, such as a phenyl group and a naphthyl group, can be mentioned, for example. Examples of the alkylaryl group include tolyl group, xylyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, and decylphenyl. Group, an alkylaryl group having 7 to 18 carbon atoms such as undecylphenyl group and dodecylphenyl group (the alkyl group may be linear or branched, and the substitution position on the aryl group is arbitrary). .

  Examples of the arylalkyl group include arylalkyl groups having 7 to 12 carbon atoms such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, and phenylhexyl group (these alkyl groups may be linear or branched). May be branched).

The hydrocarbon group having 1 to 24 carbon atoms represented by R ¹⁸ , R ^19, and R ²⁰ is preferably an alkyl group, an aryl group, or an alkylaryl group, and an alkyl group having 4 to 18 carbon atoms or a carbon number of 7 The alkylaryl group of -24 and a phenyl group are more preferable.

  Specific examples of the phosphorothioate represented by the general formula (23) include tributyl phosphorothioate, tripentyl phosphorothioate, trihexyl phosphorothioate, triheptyl phosphorothioate, and trioctyl. Phosphorothioate, trinonyl phosphorothionate, tridecyl phosphorothionate, triundecyl phosphorothionate, tridodecyl phosphorothionate, tritridecyl phosphorothionate, tritetradecyl phosphorothionate, tri Pentadecyl phosphorothioate, trihexadecyl phosphorothionate, triheptadecyl phosphorothionate, trioctadecyl phosphorothionate, trioleyl phosphorothionate, triphenyl phosphorothionate, triphenyl Resyl phosphorothioate, trixylenyl phosphorothioate, cresyl diphenyl phosphorothioate, xylenyl diphenyl phosphorothioate, tris (n-propylphenyl) phosphorothionate, tris (isopropylphenyl) phos Forothionate, tris (n-butylphenyl) phosphorothionate, tris (isobutylphenyl) phosphorothionate, tris (s-butylphenyl) phosphorothionate, tris (t-butylphenyl) phosphorothionate, etc. . Mixtures of these can also be used.

  When these phosphorus-based extreme pressure agents are contained in the grease composition for constant velocity joints of the present invention, the content is not particularly limited, but is preferably 0.01 to 15% by mass, more preferably, based on the composition. 0.05-10 mass%, More preferably, it is 0.1-5 mass%.

  Examples of the zinc-based extreme pressure agent include a zinc dithiophosphate compound represented by the following general formula (24), a zinc dithiocarbamate compound represented by the following general formula (25), the following general formula (26) or ( 27) The zinc salt of the phosphorus compound represented by 27).

(In Formula (24), R ²¹ , R ²² , R ²³ and R ²⁴ may be the same or different and each represents a hydrocarbon group having 1 or more carbon atoms.)

(In Formula (25), R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ may be the same or different and each represents a hydrocarbon group having 1 or more carbon atoms.)

[In formula (26), Y represents an oxygen atom or a sulfur atom, respectively, and at least two of three Y are an oxygen atom, R < ²⁹ >, R < ³⁰ > and R < ³¹ > may be the same or different, respectively, Represents an atom or a hydrocarbon group having 1 to 30 carbon atoms]

[In the formula (27), Y represents an oxygen atom or a sulfur atom, and at least three of the four Y are oxygen atoms, and R ³² , R ³³ and R ³⁴ may be the same or different, and each represents hydrogen. Represents an atom or a hydrocarbon group having 1 to 30 carbon atoms.

Examples of the hydrocarbon group represented by R ^{21 to} R ²⁸ in the general formulas (24) and (25) include an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, and the number of carbon atoms. Examples thereof include an alkylcycloalkyl group having 6 to 11 carbon atoms, an aryl group having 6 to 18 carbon atoms, an alkylaryl group having 7 to 24 carbon atoms, and an arylalkyl group having 7 to 12 carbon atoms.

  Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group (including all branched isomers), a butyl group (including all branched isomers), and a pentyl group (all branched isomers). Isomers), hexyl groups (including all branched isomers), heptyl groups (including all branched isomers), octyl groups (including all branched isomers), nonyl groups (all Including branched isomers), decyl group (including all branched isomers), undecyl group (including all branched isomers), dodecyl group (including all branched isomers), tridecyl group (including All branched isomers), tetradecyl group (including all branched isomers), pentadecyl group (including all branched isomers), hexadecyl group (including all branched isomers), heptadecyl Groups (including all branched isomers), octadecyl groups (all branches) Isomers), nonadecyl group (including all branched isomers), icosyl group (including all branched isomers), heicosyl group (including all branched isomers), docosyl group (all A branched isomer), a tricosyl group (including all branched isomers), a tetracosyl group (including all branched isomers), and the like.

  Specific examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.

  Further, as the alkylcycloalkyl group, specifically, a methylcyclopentyl group (including all substituted isomers), an ethylcyclopentyl group (including all substituted isomers), and a dimethylcyclopentyl group (all substituted isomers). ), Propylcyclopentyl group (including all branched and substituted isomers), methylethylcyclopentyl group (including all substituted isomers), trimethylcyclopentyl group (including all substituted isomers), butylcyclopentyl Group (including all branched isomers and substituted isomers), methylpropylcyclopentyl group (including all branched isomers and substituted isomers), diethylcyclopentyl group (including all substituted isomers), dimethylethyl Cyclopentyl group (including all substituted isomers), methylcyclohexyl group (including all substituted isomers) , Ethylcyclohexyl group (including all substituted isomers), dimethylcyclohexyl group (including all substituted isomers), propylcyclohexyl group (including all branched isomers and substituted isomers), methylethylcyclohexyl group (including All substituted isomers), trimethylcyclohexyl group (including all substituted isomers), butylcyclohexyl group (including all branched and substituted isomers), methylpropylcyclohexyl group (all branched isomers) , Including substituted isomers), diethylcyclohexyl group (including all substituted isomers), dimethylethylcyclohexyl group (including all substituted isomers), methylcycloheptyl group (including all substituted isomers), Ethylcycloheptyl group (including all substituted isomers), dimethylcycloheptyl group (including all substituted isomers) ), Propylcycloheptyl group (including all branched isomers and substituted isomers), methylethylcycloheptyl group (including all substituted isomers), trimethylcycloheptyl group (including all substituted isomers) , Butylcycloheptyl group (including all branched isomers and substituted isomers), methylpropylcycloheptyl group (including all branched and substituted isomers), diethylcycloheptyl group (all substituted isomers) And dimethylethylcycloheptyl group (including all substituted isomers) and the like.

  Examples of the aryl group include a phenyl group and a naphthyl group.

  Examples of the alkylaryl group include a tolyl group (including all substituted isomers), a xylyl group (including all substituted isomers), an ethylphenyl group (including all substituted isomers), and a propylphenyl group (all Branched isomers, including substituted isomers, methylethylphenyl group (including all substituted isomers), trimethylphenyl group (including all substituted isomers), butylphenyl group (all branched isomers) , Including substituted isomers), methylpropylphenyl group (including all branched isomers and substituted isomers), diethylphenyl group (including all substituted isomers), dimethylethylphenyl group (all substituted isomers) ), Pentylphenyl group (including all branched isomers and substituted isomers), hexylphenyl group (including all branched and substituted isomers), heptylphenyl group (all Branched isomers, including substituted isomers), octylphenyl group (including all branched isomers and substituted isomers), nonylphenyl group (including all branched isomers and substituted isomers), decyl Phenyl group (including all branched isomers and substituted isomers), undecylphenyl group (including all branched isomers and substituted isomers), dodecylphenyl group (all branched isomers and substituted isomers) ), Tridecylphenyl group (including all branched isomers and substituted isomers), tetradecylphenyl group (including all branched and substituted isomers), pentadecylphenyl group (including all branched isomers) Branched isomers, including substituted isomers), hexadecylphenyl group (including all branched isomers and substituted isomers), heptadecylphenyl group (including all branched isomers and substituted isomers), octadecyl Phenyl group (all branches Sex body, including isomers), and the like.

  Examples of the arylalkyl group include a benzyl group, a phenethyl group, a phenylpropyl group (including all branched isomers), a phenylbutyl group (including all branched isomers), and the like.

Moreover, regarding the zinc salt of the phosphorus compound represented by the general formula (26) or (27), the hydrocarbon group having 1 to 30 carbon atoms represented by R ^{29 to} R ³⁴ in the formula is specifically Includes an alkyl group, a cycloalkyl group, an alkenyl group, an alkylcycloalkyl group, an aryl group, an alkylaryl group, an arylalkyl group, and the like.

  Examples of the alkyl group include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and the like. Group, hexadecyl group, heptadecyl group, octadecyl group and other alkyl groups (these alkyl groups may be linear or branched).

  As said cycloalkyl group, C5-C7 cycloalkyl groups, such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, can be mentioned, for example. Examples of the alkylcycloalkyl group include a methylcyclopentyl group, a dimethylcyclopentyl group, a methylethylcyclopentyl group, a diethylcyclopentyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a methylethylcyclohexyl group, a diethylcyclohexyl group, a methylcycloheptyl group, Examples thereof include an alkylcycloalkyl group having 6 to 11 carbon atoms such as a dimethylcycloheptyl group, a methylethylcycloheptyl group, and a diethylcycloheptyl group (the substitution position of the alkyl group with the cycloalkyl group is also arbitrary).

  Examples of the alkenyl group include butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, An alkenyl group such as an octadecenyl group (these alkenyl groups may be linear or branched, and the position of the double bond is also optional).

  As said aryl group, aryl groups, such as a phenyl group and a naphthyl group, can be mentioned, for example. Examples of the alkylaryl group include tolyl group, xylyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, and decylphenyl. Group, an alkylaryl group having 7 to 18 carbon atoms such as undecylphenyl group and dodecylphenyl group (the alkyl group may be linear or branched, and the substitution position on the aryl group is arbitrary). .

  Examples of the arylalkyl group include arylalkyl groups having 7 to 12 carbon atoms such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, and phenylhexyl group. It may be branched).

The hydrocarbon group having 1 to 30 carbon atoms represented by R ^{29 to} R ³⁴ is preferably an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 24 carbon atoms, more preferably 3 to 3 carbon atoms. An alkyl group having 18 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms.

R ²⁹ , R ³⁰ and R ³¹ may be the same or different and each represents a hydrogen atom or the above hydrocarbon group, and 1 to 3 of R ²⁹ , R ³⁰ and R ³¹ are the above hydrocarbon groups. It is preferable that 1 to 2 is the above hydrocarbon group, and more preferably 2 is the above hydrocarbon group.

R ³² , R ³³ and R ³⁴ may be the same or different, and each represents a hydrogen atom or the above hydrocarbon group. Among R ³² , R ³³ and R ³⁴ , 1 to 3 are the above hydrocarbons. It is preferably a group, 1 to 2 are more preferably the hydrocarbon group, and 2 are more preferably the hydrocarbon group.

  In the phosphorus compound represented by the general formula (26), at least two of the three Y need to be oxygen atoms, but it is preferable that all Y are oxygen atoms.

  Further, in the phosphorus compound represented by the general formula (27), at least three of the four Ys need to be oxygen atoms, but it is preferable that all Ys are oxygen atoms.

  Examples of the phosphorus compound represented by the general formula (26) include phosphorous acid and monothiophosphorous acid; phosphorous acid monoester having one hydrocarbon group having 1 to 30 carbon atoms and monothiophosphorous acid mono Ester; Phosphorous acid diester having two hydrocarbon groups having 1 to 30 carbon atoms, monothiophosphorous acid diester; Phosphorous acid triester having three hydrocarbon groups having 1 to 30 carbon atoms, monothiophosphorous acid Acid triesters; and mixtures thereof. Among these, phosphorous acid monoester and phosphorous acid diester are preferable, and phosphorous acid diester is more preferable.

  Examples of the phosphorus compound represented by the general formula (27) include phosphoric acid, monothiophosphoric acid; phosphoric acid monoester having one hydrocarbon group having 1 to 30 carbon atoms, monothiophosphoric acid monoester; And phosphoric acid diesters and monothiophosphoric acid diesters having two hydrocarbon groups having 1 to 30 carbon atoms; phosphoric acid triesters and monothiophosphoric acid triesters having three hydrocarbon groups having 1 to 30 carbon atoms; and mixtures thereof. It is done. Among these, phosphoric acid monoester and phosphoric acid diester are preferable, and phosphoric acid diester is more preferable.

  The structure of the zinc salt of the phosphorus compound represented by the general formula (26) or (27) varies depending on the number of OH groups or SH groups of the phosphorus compound, and therefore the structure is not limited at all. For example, when 1 mol of zinc oxide is reacted with 2 mol of phosphoric acid diester (one OH group), it is considered that a compound having a structure represented by the following formula (28) is obtained as a main component. (R in the formula represents a hydrocarbon group having 1 to 30 carbon atoms).

  In addition, for example, when 1 mol of zinc oxide and 1 mol of phosphoric acid monoester (two OH groups) are reacted, a compound having a structure represented by the following formula (29) is considered to be obtained as a main component. It is considered that polymerized molecules also exist (R in the formula represents a hydrocarbon group having 1 to 30 carbon atoms).

  The grease composition for constant velocity joints of the present invention is a complex of a fatty acid salt and a carbonate, wherein the fatty acid is overbased with the carbonate (hereinafter referred to as “carbonate dispersed overbase”). And at least one selected from organic acid salts.

  The carbonate-dispersed overbased fatty acid salt is obtained by overbasing a fatty acid salt with a carbonate by dispersing the carbonate in the fatty acid salt.

  With respect to the fatty acid salt constituting the carbonate-dispersed overbased fatty acid salt, the fatty acid may be linear or branched. The fatty acid may be saturated or unsaturated, but is preferably an unsaturated fatty acid from the viewpoint of solubility in the base oil. There is no particular limitation on the number of unsaturated bonds, but it is preferably one. Further, the carbon number of the fatty acid is not particularly limited, but those having 10 to 25 carbon atoms are preferred from the viewpoint of the dispersibility of the carbonate fine particles.

  Specific examples of preferred fatty acids used in the carbonate-dispersed overbased fatty acid salt of the present invention include oleic acid (18 carbon atoms, one unsaturated bond), erucic acid (22 carbon atoms, one unsaturated bond). Linoleic acid (18 carbon atoms, 2 unsaturated bonds), linolenic acid (18 carbon atoms, 3 unsaturated bonds), etc. Among them, oleic acid is more preferable.

  Examples of the fatty acid salt constituting the carbonate-dispersed overbased fatty acid salt include alkali metal salts and alkaline earth metal salts of the fatty acids described above, and alkaline earth metal salts such as magnesium, barium, and calcium. It is preferable that it is a calcium salt.

  Examples of the carbonate constituting the carbonate-dispersed overbased fatty acid salt include alkali metal salts and alkaline earth metal salts, and more specifically lithium salts, sodium salts, potassium salts, magnesium salts, calcium salts. , Barium salts, and the like, and alkaline earth metal salts are preferable, and calcium salts are more preferable.

  In the carbonate-dispersed overbased fatty acid salt, the carbonate exists as fine particles. The particle size in this case is not particularly limited, but the average particle size is preferably 50 nm or more, more preferably 100 nm or more, from the viewpoint of providing more sufficient anti-flaking performance and anti-seizure performance. More preferably, it is still more preferably 300 nm or more, still more preferably 500 nm or more, particularly preferably 1000 nm or more, and most preferably 2000 nm or more. Here, the average particle diameter means an average particle diameter measured by a dynamic light scattering type particle size distribution system and calculated by the Marquat method.

  In the carbonate-dispersed overbased fatty acid salt of the present invention, the mixing ratio of the fatty acid salt and the carbonate is not particularly limited, but from the viewpoint of further improving the flaking resistance and seizure resistance, The carbonate is preferably 10 parts by weight or more, more preferably 20 parts by weight or more, still more preferably 30 parts by weight or more, still more preferably 40 parts by weight or more, and particularly preferably 50 parts by weight or more. From the viewpoint of solubility in a lubricating base oil, the carbonate is preferably 1000 parts by weight or less, more preferably 500 parts by weight or less, and still more preferably 400 parts by weight or less, per 100 parts by weight of the fatty acid salt. The amount is preferably 300 parts by weight or less, particularly preferably 200 parts by weight or less.

  The method for producing the carbonate-dispersed overbased fatty acid salt is arbitrary. Specifically, for example, the above-described fatty acid salt is dissolved in carrier oil, and an alkali metal base, an alkaline earth metal base, or the like is present. It can be produced by blowing carbon dioxide into the system. As the carrier oil here, those exemplified as the lubricating base oil of the grease composition for constant velocity joints of the present invention can be used. Examples of the base of alkali metal or alkaline earth metal include hydroxides and oxides, and more specifically, calcium hydroxide, calcium oxide, magnesium oxide, barium oxide and the like.

  The carbonate-dispersed overbased fatty acid salt in the present invention is usually obtained in a state dissolved in the carrier oil. From the viewpoint of solubility in a lubricating base oil, the total of the fatty acid salt and the carbonate is obtained. The carrier oil is preferably 10 parts by weight or more, more preferably 15 parts by weight or more, still more preferably 20 parts by weight or more, and particularly preferably 25 parts by weight or more with respect to 100 parts by weight. The carrier oil is preferably 1000 parts by weight or less, more preferably 700 parts by weight or less, still more preferably 500 parts by weight or less, particularly preferably 400 parts by weight based on 100 parts by weight of the total amount of the fatty acid salt and carbonate. Less than parts by weight.

  Further, in the production process of carbonate-dispersed overbased fatty acid salt, methanol may be added to the reaction system in order to promote the production of carbonate fine particles.

  Furthermore, as the carbonate-dispersed overbased fatty acid salt of the present invention, a mixture obtained by overbasing a mixture of a fatty acid salt and another organic acid salt such as a sulfonate may be used.

  The content of the carbonate-dispersed overbased fatty acid salt in the present invention is preferably 0.05% by mass, more preferably 0.1% by mass, based on the total amount of the composition. When the content of the carbonate-dispersed overbased fatty acid salt is less than 0.05% by mass, the effect of improving the flaking resistance and seizure resistance due to the addition of the carbonate-dispersed overbased fatty acid salt is insufficient. Tend to be. The content of the carbonate-dispersed overbased fatty acid salt is preferably 10% by mass or less, more preferably 5.0% by mass, based on the total amount of the composition. When the content of the carbonate-dispersed overbased fatty acid salt exceeds 10% by mass, there is a tendency that the effect of improving the flaking resistance and the seizure resistance corresponding to the added amount cannot be obtained. Here, the content of the carbonate-dispersed overbased fatty acid salt is the total amount of the content of the fatty acid salt excluding the carrier oil and the content of the carbonate.

  The base number of the carbonate-dispersed overbased fatty acid salt of the present invention is not particularly limited, but is more excellent in anti-flaking and seizure resistance, so that it is usually 50 mg KOH / g in a state dissolved in a carrier oil. As mentioned above, Preferably it is 100 mgKOH / g or more, More preferably, it is 150 mgKOH / g or more, More preferably, it is 200 mgKOH / g or more, Most preferably, it is 250 mgKOH / g or more. Although there is no restriction | limiting in particular about an upper limit, Generally it is 600 mgKOH / g or less. The base number referred to here is 6. JIS K 2501 “Petroleum products and lubricating oils—neutralization test method”. The base number (mgKOH / g) measured by the hydrochloric acid method based on the above.

  As the organic acid salt, sulfonate, phenate, salicylate, and a mixture thereof are preferably used. The positive components of these organic acid salts include alkali metals such as sodium and potassium; alkaline earth metals such as magnesium, calcium and barium; ammonia and alkylamines having 1 to 3 carbon atoms (monomethylamine, dimethyl). Amines, trimethylamines, monoethylamines, diethylamines, triethylamines, monopropylamines, dipropylamines, tripropylamines, etc.), alkanolamines having an alkanol group having 1 to 3 carbon atoms (monomethanolamine, dimethanolamine, trimethanolamine, Monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine and the like. Among these, an alkali metal or an alkaline earth metal is preferable, and calcium is particularly preferable. When the positive component of the organic acid salt is an alkali metal or alkaline earth metal, higher lubricity tends to be obtained.

  The base number of the organic acid salt is preferably 50 to 500 mgKOH / g, more preferably 100 to 450 mgKOH / g. When the base number of the organic acid salt is less than 100 mgKOH / g, the lubricity improving effect due to the addition of the organic acid salt tends to be insufficient. On the other hand, the organic acid salt having a base number exceeding 500 mgKOH / g is usually Each is not preferable because it is very difficult to manufacture and difficult to obtain. The base number referred to here is 7. JIS K 2501 “Petroleum products and lubricants—neutralization number test method”. The base number [mgKOH / g] by the perchloric acid method measured according to the above.

  The content of the organic acid salt is preferably 0.1 to 30% by mass, more preferably 0.5 to 25% by mass, and further preferably 1 to 20% by mass, based on the total amount of the composition. is there. When the content of the organic acid salt is less than the lower limit, the effect of improving the anti-flaking property and seizure resistance due to the addition of the organic acid salt tends to be insufficient. On the other hand, when the content exceeds the upper limit, the grease composition There is a tendency that the stability of the product is lowered and precipitates are easily formed.

  As the sulfonate, one produced by any method can be used. For example, alkali metal salts, alkaline earth metal salts, amine salts and mixtures of alkyl aromatic sulfonic acids obtained by sulfonating alkyl aromatic compounds having a molecular weight of 100 to 1500, preferably 200 to 700 are used. it can. As the alkyl aromatic sulfonic acid here, generally, a sulfonated alkyl aromatic compound of a lubricating oil fraction of mineral oil, a petroleum sulfonic acid such as so-called mahogany acid, which is by-produced during white oil production, and a detergent Alkylbenzene having a linear or branched alkyl group obtained by by-production from a raw material alkylbenzene production plant or alkylating polyolefin to benzene, or alkylnaphthalene such as dinonylnaphthalene And synthetic sulfonic acids such as those obtained by sulphonation of sulphonate. In addition, the above alkyl aromatic sulfonic acid and an alkali metal base (such as an alkali metal oxide or hydroxide), an alkaline earth metal base (such as an alkaline earth metal oxide or hydroxide), or the above-mentioned So-called neutral (normal salt) sulfonates obtained by reacting with amines (ammonia, alkylamines, alkanolamines, etc.); neutral (normal salt) sulfonates, excess alkali metal bases, alkaline earth metal bases Or so-called basic sulfonates obtained by heating an amine in the presence of water; reacting a neutral (normal salt) sulfonate with an alkali metal base, an alkaline earth metal base or an amine in the presence of carbon dioxide. So called carbonate overbased (superbasic) sulfonates; neutral (normal salt) sulfonates with alkali React with genus bases, alkaline earth metal bases or amines and boric acid compounds such as boric acid or boric anhydride, or carbonate overbased (superbasic) sulfonates with boric acid or boric anhydride And so-called borate overbased (superbasic) sulfonates produced by reacting boric acid compounds; and mixtures thereof.

  Further, as the phenate, specifically, in the presence or absence of elemental sulfur, an alkylphenol having 1 to 2 alkyl groups having 4 to 20 carbon atoms and an alkali metal base (alkali metal oxide or Hydroxides), alkaline earth metal bases (alkaline earth metal oxides, hydroxides, etc.) or neutrals obtained by reacting with the amines mentioned above (ammonia, alkylamines, alkanolamines, etc.) Phenates; neutral phenates and excess alkali metal bases, alkaline earth metal bases or amines obtained by heating in the presence of water, so-called basic phenates; neutral phenates in the presence of carbon dioxide So-called carbonate overbased (superbase) obtained by reacting with metal bases, alkaline earth metal bases or amines ) Phenates; neutral phenates are reacted with alkali metal bases, alkaline earth metal bases or amines and boric acid compounds such as boric acid or boric anhydride, or carbonate overbased (superbasic) phenates And so-called borate overbased (superbasic) phenates produced by reacting boric acid compounds such as boric acid or boric anhydride; and mixtures thereof.

  Further, as the salicylate, specifically, an alkyl salicylic acid having 1 to 2 alkyl groups having 4 to 20 carbon atoms and an alkali metal base (alkali metal oxide) in the presence or absence of elemental sulfur. And hydroxides), alkaline earth metal bases (such as alkaline earth metal oxides and hydroxides) or the above-described amines (such as ammonia, alkylamines and alkanolamines). So-called basic salicylate obtained by heating neutral salicylate and excess alkali metal base, alkaline earth metal base or amine in the presence of water; neutral salicylate in the presence of carbon dioxide gas So-called carbonate overbases obtained by reacting with alkali metal bases, alkaline earth metal bases or amines (Superbasic) salicylates; neutral salicylates react with alkali metal bases, alkaline earth metal bases or amines and boric acid compounds such as boric acid or boric anhydride, or carbonate overbased (superbases) A so-called borate overbased (superbasic) salicylate produced by reacting a metal salicylate with a boric acid compound such as boric acid or anhydrous boric acid; and a mixture thereof.

  The penetration of the grease composition for constant velocity joints of the present invention is preferably 220 or more, more preferably 265 or more. When the penetration is less than 220, the grease becomes excessively hard and the effect of the present invention tends not to be sufficiently exhibited. Moreover, the said penetration degree becomes like this. Preferably it is 430 or less, More preferably, it is 400 or less. When the blending degree exceeds 430, the grease becomes excessively soft, and it tends to be difficult to enclose the grease composition in the constant velocity joint. In addition, the penetration degree here means the penetration degree immediately after 60 reciprocal mixings measured by 5.3 “Consistency test method” of JIS K2220 “Grease”.

  The grease composition for constant velocity joints of the present invention is a solid lubricant, antioxidant, oiliness agent, rust inhibitor, viscosity index improvement as necessary to further improve the performance unless the properties are impaired. An agent or the like can be contained.

  Specific examples of the solid lubricant include boron nitride, graphite fluoride, polytetrafluoroethylene, molybdenum disulfide, antimony sulfide, and alkali (earth) metal borates.

  Specific examples of the antioxidant include phenol compounds such as 2,6-di-t-butylphenol and 2,6-di-t-butyl-p-cresol; dialkyldiphenylamine, phenyl-α-naphthylamine, p- Amine compounds such as alkylphenyl-α-naphthylamine; sulfur compounds; phenothiazine compounds.

  Specific examples of oily agents include amines such as laurylamine, myristylamine, palmitylamine, stearylamine, oleylamine; higher alcohols such as lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, oleyl alcohol; laurin Higher fatty acids such as acid, myristic acid, palmitic acid, stearic acid, oleic acid; fatty acid esters such as methyl laurate, methyl myristate, methyl palmitate, methyl stearate, methyl oleate; laurylamide, myristylamide, Amides such as palmitylamide, stearylamide, oleylamide; oils and fats.

  Specific examples of the rust inhibitor include metal soaps; polyhydric alcohol partial esters such as sorbitan fatty acid esters; amines; phosphoric acid;

  Specific examples of the viscosity index improver include polymethacrylate, polyisobutylene, and polystyrene.

  To prepare the grease composition for constant velocity joints of the present invention, for example, a lubricant base oil, a thickener, carbon black having an average particle size of 500 nm or less, an organic molybdenum compound, and other additives as required Can be obtained by mixing and stirring and passing through a roll mill or the like. Carbon black having an average particle size of 500 nm or less after a thickener is prepared in a lubricant base oil by adding a raw material component of a thickener to the lubricant base oil in advance and melting and stirring and mixing. In addition, an organic molybdenum compound and other additives as necessary may be mixed and stirred and passed through a roll mill or the like.

  The grease composition for constant velocity joints of the present invention having the above-described structure is excellent in flaking resistance, seizure resistance, wear resistance and low friction properties, and improves the performance and life of constant velocity joints. It can be achieved at a high level. The constant velocity joint to which the grease composition for a constant velocity joint of the present invention is applied is not particularly limited. For example, fixed type constant velocity joints such as a barfield joint, a zeppa joint, an undercut free joint, a double offset joint, and a tripod Examples thereof include slide type constant velocity joints such as joints and cross groove joints.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

[Examples 1-7, Comparative Examples 1-4]
In Examples 1 to 6 and Comparative Examples 1 to 4, a solvent refined paraffinic mineral oil having a kinematic viscosity at 40 ° C. of 126 mm ² / s was used as the lubricating base oil, and diphenylmethane 4,4′-diisocyanate was used as the base oil. The various amines and alcohols shown in Tables 1 to 3 dissolved in the base oil were added thereto. Next, various additives shown in Table 1 were added to the generated gel substance, stirred, and then passed through a roll mill to obtain a grease composition.

  Moreover, in Example 7, lithium 12-hydroxystearate was added to the lubricating base oil as a thickener instead of diisocyanate, alcohol and amine. Next, various additives shown in Table 2 were added, stirred and passed through a roll mill to obtain a grease composition.

  In Tables 1 to 3, dihydrocarbyl polysulfite is sulfurized polyisobutylene (sulfur content 45% by mass), sulfurized fat is sulfurized lard (sulfur content 30% by mass), and antioxidant is amine-based antioxidant. Each means an agent (phenyl-α-naphthylamine).

[Tradical endurance test]
The following bench-top durability tests were performed on the grease compositions of Examples 1 to 7 and Comparative Examples 1 to 3.

  Considering the driving pattern of the car, using a commercially available # 82 sized barfield joint under the condition that the rotation speed, torque, and operating angle are changed to one cycle, the joint will be seized or a frame will be formed in each part. The number of cycles until king occurred was evaluated. The obtained results are shown in Tables 1-3.

Claims (3)

A grease composition for a constant velocity joint, comprising a lubricating base oil, a thickener, carbon black having an average particle size of 500 nm or less, and an organic molybdenum compound. The grease composition for a constant velocity joint according to claim 1, further comprising at least one selected from a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and a zinc-based extreme pressure agent. A complex of a fatty acid salt and a carbonate, wherein the fatty acid further contains at least one selected from a complex in which the fatty acid is overbased by the carbonate, and an organic acid salt. The grease composition for constant velocity joints according to 1 or 2.