KR20220125792A - grease composition - Google Patents

Abstract

Lubricating grease used to lubricate a machine element having a reciprocating sliding ball interposed therebetween, and to maintain flaking resistance in a machine element having a reciprocating sliding ball interposed therebetween, even under high loads. is provided Accordingly, the present invention provides a grease composition comprising a base oil (a), a diurea compound (b), an amide compound (c), and a thiophosphorus compound or thiophosphoric acid ester compound (d), the diurea compound (b) includes a compound represented by formula (1) R ₁ -NHCONH-R ₂ -NHCONH-R ₃ (1), wherein R ₁ and R ₃ are acyclic aliphatic having 8 to 20 carbon atoms. A hydrocarbon group is shown, and R< ₂ > represents a diphenylmethane group.

Description

grease composition

The present invention relates to a grease composition.

Mechanical elements having reciprocating sliding balls interposed therebetween include linear guides, ball screws, and constant velocity joints, and the environments in which they are used vary. Rolling and sliding can occur simultaneously in machine elements, and the lubricating environment can be harsh. Under these conditions, contact between the surfaces of the rolling member may easily occur, and wear or seizure may occur when the contact is significant.

Extreme pressure agents are usually added to lubricants such as lubricants and greases to prevent wear or seizure and to protect machine components. Well-known extreme pressure agents include sulfur-based extreme pressure agents, phosphorus-based extreme pressure agents, sulfur-phosphorus organic compounds, and molybdenum compounds. Among these extreme pressure agents, organic extreme pressure agents are particularly popular because they exhibit excellent extreme pressure performance, and they are currently widely used in lubricating oil compositions.

For example, Japanese Patent JP200111481A discloses a urea thickener, molybdenum sulfide dialkyldithiocarbamate, molybdenum disulfide, sulfur-phosphorus extreme pressure agent to improve lubricity in areas prone to wear and likely to cause problems such as abnormal vibration. A grease composition for a sliding constant velocity joint comprising, for example, zinc dithiophosphate or thiophosphate, and a fatty acid amide is disclosed. According to this document, the generation of thrust induced in the constant velocity joint causes problems such as reduced durability of the constant velocity joint, abnormal vibration of the vehicle, and deterioration of ride comfort, but the use of the technology disclosed in this patent document reduces wear and , suppress vibration and improve durability.

Japanese Patent JP2003321694A discloses that a grease composition contains a urea thickener and an organic sulfonate to prevent flaking from metal fatigue caused by thinning of the oil film despite an attempt to thicken the oil film, and Disclosed is a technique for extending the flaking service life due to the present invention.

Japanese Patent JP200382374A discloses that a rolling bearing grease composition contains a urea thickener and benzotriazole and/or derivatives to prevent flaking from metal fatigue caused by thinning of the oil despite an attempt to thicken the oil film Disclosed is a technique for extending a king service life.

Japanese patent JP2008239687A discloses a technique in which a bearing grease composition contains a urea thickener, an alkyl phosphorothioate compound, and an aliphatic amine.

Japanese Patent JP201725189A states that the grease composition contains urea thickener, molybdenum dithiocarbamate, zinc dithiocarbamate, and zinc sulfonate to prevent metal-to-metal contact during lubrication even under high speed/high surface pressure conditions. Techniques for forming and maintaining friction reducing additive films are disclosed.

The lubricant and grease compositions of Japanese Patent JP200111481A, Japanese Patent JP2003321694A, Japanese Patent JP200382374, Japanese Patent JP2008239687, and Japanese Patent JP201725189A exhibit excellent wear resistance and film-forming ability under certain conditions or for certain mechanical elements, but in various No composition has been provided that can stably maintain the overall balance between abrasion resistance and film-forming ability during reciprocating sliding under high loads. In particular, the reciprocal sliding effect on flaking under various high loads has not been studied and may not be sufficient.

In view of this situation, an object of the present invention is even when rolling stops briefly during reversal of reciprocating sliding, oil film cannot be sufficiently produced, metal-to-metal contact occurs, and frictional wear tends to become excessive. Even maintaining and improving the service life of machine parts. It is also an object of the present invention to form a strong additive film, to keep the already formed film stable even after repeated operations, and to provide stable lubricating properties. In other words, it is an object of the present invention to provide a grease composition which can be used to lubricate a machine element having reciprocating sliding balls interposed therebetween and to maintain flaking resistance even under high loads. .

As a result of extensive research carried out to achieve the above-mentioned object, the present inventors have prepared an amide compound, a thiophosphorous acid compound or a thiophosphoric acid ester compound, and a specific diurea (diurea) compound. ) compound can be used on machine elements having reciprocating sliding balls interposed therebetween to improve the flaking resistance. The present invention is the result of this discovery.

Specifically, the present invention is as follows.

Aspect (1) of the present invention provides a grease composition comprising a base oil (a), a diurea compound (b), an amide compound (c), and a thiophosphorus compound or thiophosphoric acid ester compound (d) and the diurea compound (b) includes a compound represented by Formula (1),

R ₁ -NHCONH-R ₂ -NHCONH-R ₃ (1)

In the above formula, R ₁ and R ₃ represent an acyclic aliphatic hydrocarbon group having 8 to 20 carbon atoms, and R ₂ represents a diphenylmethane group.

Aspect (2) of the present invention is the grease composition according to aspect (1) of the present invention, wherein the diurea compound (b) is an acyclic aliphatic hydrocarbon group in which R ₁ and R ₃ in Formula 1 have 8 to 12 carbon atoms. or a diurea compound (b) which is an acyclic aliphatic hydrocarbon group having 14 to 20 carbon atoms.

Aspect (3) of the present invention is a grease composition according to aspect (1) or (2) of the present invention, further comprising a saturated or unsaturated fatty acid having 4 to 18 carbon atoms, or a metal salt thereof (e) .

Aspect (4) of the present invention is the grease composition according to any one of aspects (1) to (3) of the present invention, further comprising an amine compound (f) represented by formula (2);

R₄-NH-R₅-NH₂ (2)

In the above formula, R ₄ represents a saturated or unsaturated hydrocarbon group having 5 to 18 carbon atoms, and R ₅ represents a saturated or unsaturated hydrocarbon group having 2 to 3 carbon atoms.

Aspect (5) of the present invention is the grease composition according to any one of aspects (1) to (4) of the present invention, wherein the amide compound (c) is an amide compound represented by formula (3) or formula (4) ( c) comprising;

R ₆ -CO-NH ₂ (3)

R ₆ -CO-NH-R ₇ -NH-CO-R ₆ (4)

In the above formula, R ₆ represents a saturated or unsaturated hydrocarbon group having 15 to 17 carbon atoms, and R ₇ represents a methylene group or an ethylene group.

Aspect (6) of the present invention is the grease composition according to any one of aspects (1) to (5) of the present invention, wherein the thiophosphorus compound comprises a thiophosphorus compound represented by the formula (5), The phosphoric acid ester compound includes a thiophosphoric acid ester compound represented by the formula (6),

(R ₈ S) ₃ P (5)

(R ₉ O) ₃ PS (6)

wherein R ₈ represents a saturated or unsaturated hydrocarbon group having 8 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms, R ₉ is a saturated or unsaturated hydrocarbon group having 8 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms.

1 is a schematic diagram showing an overview of the flaking resistance tester.

The present invention is a grease composition that can be used to lubricate a machine element having reciprocating sliding balls interposed therebetween and to maintain flaking resistance even under high loads in a machine element having reciprocating sliding balls interposed therebetween. can provide

In the present application, "hydrocarbon group" refers to an atomic group obtained when some hydrogen atoms are removed from a hydrocarbon.

When the name of a compound appears in this application, the name includes all isomers of the compound.

In the present application, the amine compound forming the diurea compound described below is referred to as the starting amine compound. The starting amine compound and the amine compound (f) may be the same or different. When the amount of the amine compound (f) is referred to herein, the amount does not include the starting amine compound.

The grease composition of the present invention comprises a base oil (a), a diurea compound (b), an amide compound (c), and a thiophosphorus compound or thiophosphoric acid ester compound (d).

In the present invention, the diurea compound (b) includes a compound represented by formula (1),

R ₁ -NHCONH-R ₂ -NHCONH-R ₃ (1)

In the above formula, R ₁ and R ₃ represent an acyclic aliphatic hydrocarbon group having 8 to 20 carbon atoms, and R ₂ represents a diphenylmethane group.

The diurea compound (b) of the present invention is generally prepared by reacting an isocyanate with a primary amine (starting amine compound). It should be understood that the morphology of the thickener fibers in the diurea thickener depends on the combination of the isocyanate and the primary amine (starting amine compound), and the flow characteristics of the resulting grease composition vary considerably.

The aliphatic urea grease using the diurea compound (b) of Formula 1 as a thickener may be a urea grease composed of an alicyclic amine and an aromatic amine, or a urea grease composed of a mixture of an aliphatic amine and an alicyclic amine and/or an aromatic amine, , they should be understood as having different flow characteristics. It should also be understood that greases using the diurea compound (b) of formula (1) as a thickener tend to have excellent intervention properties at the lubricating interface, and play an important role in protecting machine elements. The grease using the diurea compound (b) of compound 1 as a thickener has good base oil solubility and is interposed at the lubricating interface with the base oil, so that the different flow forms of the fibers interact with each other to provide good flow behavior and provide effective lubrication It should also be understood as making It should also be understood that these effects are pronounced in aliphatic urea greases containing unsaturated aliphatic amines.

The grease composition of the present invention containing the diurea compound (b), the amide compound (c), and the thiophosphite compound or thiophosphate ester compound (d) has a remarkable effect in improving the anti-flaking performance described below, , fatty acids or fatty acid salts, and the addition of an amine compound (f) different from the starting amine compound used to form the diurea compound (b) improves the anti-flaking performance of a machine element having a reciprocating sliding ball interposed therebetween. It should also be understood to have the effect of further improving.

This has the effect of thickening the lubricating film due to the improved supply of the grease composition to the lubricating interface obtained from the excellent flow characteristics exhibited by the aliphatic diurea thickener in the fluid lubrication range with high reciprocating sliding speed, diurea compound (b) Besides the lubricating film of In the boundary lubrication region and the mixed lubrication region where the oil film near the end point of the reciprocating motion approaches zero, thiophosphite compound or thiophosphite contained in the grease composition abundantly supplied to the lubricating interface due to the excellent flow characteristics of the grease It should also be understood that the formic acid ester compound (d) and the amine compound (f) are adsorbed on the metal surface, and a strong coating formed on the interface due to a tribochemical reaction exhibits excellent anti-flaking performance.

The grease composition of the present invention contains a base oil (a). There is no specific limitation on the base oil used in the present invention as long as the effect of the present invention is not impaired. The base oil (a) may be a mineral oil, a synthetic oil, an animal oil or a vegetable oil, or any mixture thereof. Specific examples are those of the American Petroleum Institute (API) Group 1 to Group 5 base oil category. The API base oil category is a broad classification of base oil substances defined by the American Petroleum Institute to create guidelines for lubricating base oils.

There is no particular limitation on the mineral oil used in the present invention. However, preferred examples are lubricating oil fractions obtained by atmospheric distillation and vacuum distillation of crude oil by one or more refining methods such as solvent degassing, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment. Paraffinic or naphthenic mineral oil obtained by applying to These may be used alone or in combination of two or more.

There is no particular limitation on the synthetic oil used in the present invention. However, preferred examples include poly α-olefin (PAO) and hydrocarbon synthetic oil (oligomer). PAOs are α-olefin homopolymers or copolymers. The α-olefin is a compound having a C-C double bond at the terminal, and specific examples include butene, butadiene, hexene, cyclohexene, methylcyclohexene, octene, nonene, decene, dodecene, tetradecene, hexadecene, octadecene, and eico. Includes Sen. Examples of hydrocarbon synthetic oils (oligomers) include ethylene, propylene, and isobutene homopolymers or copolymers. These may be used alone or in combination of two or more. These compounds may have any isomeric structure, as long as they have a C-C double bond at the terminal, and may have a branched structure or a linear structure. These structural isomers and positional isomers having a double bond may be used in combinations of two or more. Of these olefins, linear olefins having 6 to 30 carbon atoms are preferred because the flash point is low when the number of carbon atoms is 5 or less, the viscosity is high when the number of carbon atoms is 31 or more, and such olefins are impractical.

In the present invention, a gas-to-liquid (GTL) base oil synthesized using the Fischer-Tropsch method for converting natural gas into a liquid fuel may be used as the base oil (a). Compared to mineral base oils refined from crude oil, GTL base oils have very low sulfur and aromatics content, and very high paraffin content. Consequently, it has excellent oxidative stability and very low evaporative losses, making it ideal for use as the base oil (a) in the present invention.

The grease composition of the present invention contains the diurea compound (b) represented by the formula (1),

R ₁ -NHCONH-R ₂ -NHCONH-R ₃ (1)

In the above formula, R ₁ and R ₃ represent an acyclic aliphatic hydrocarbon group having 8 to 20 carbon atoms, and R ₂ represents a diphenylmethane group.

R ₁ and R ₃ may be any acyclic aliphatic hydrocarbon group, and may be a linear or branched saturated or unsaturated aliphatic hydrocarbon group. R ₁ and R ₃ may have the same structure or different structures.

The diurea compound (b) of the present invention can be obtained by using the reaction of the following formula (7).

NCO-R ₂ -OCN + R ₁ -NH ₂ + R ₃ -NH ₂ → R ₁ -NHCONH-R ₂ -NHCONH-R ₃ (7)

R ₁ and R ₃ are preferably an acyclic aliphatic hydrocarbon group having 8 to 12 carbon atoms or an acyclic aliphatic hydrocarbon group having 14 to 20 carbon atoms. More preferably, one of R ₁ and R ₃ is an acyclic aliphatic hydrocarbon group having 8 to 12 carbon atoms, and the other is an acyclic aliphatic hydrocarbon group having 14 to 20 carbon atoms. When R ₁ and R ₃ have these structures, a grease composition having much better wear resistance and flaking resistance can be obtained.

The diurea compound (b) of the present invention may be used alone or in combination of two or more.

The grease composition of the present invention contains an amide compound (c). There is no specific limitation on the amide compound (c) used in the present invention as long as the effect of the present invention is not impaired. Preferred examples of the amide compound (c) that can be used in the present invention are an aliphatic amide compound represented by the following formula (3) or an aliphatic bisamide compound represented by the following formula (4). When the amide compound (c) has one of these structures, a grease compound having much better wear resistance and flaking resistance can be obtained.

R ₆ -CO-NH ₂ (3)

R ₆ -CO-NH-R ₇ -NH-CO-R ₆ (4)

In these formulas, R ₆ represents a saturated or unsaturated hydrocarbon group having 15 to 17 carbon atoms, and R ₇ represents a methylene group or an ethylene group.

Specific examples of the aliphatic amide compound and the aliphatic bisamide compound include palmitic acid amide, palmitoleic acid amide, maggaric acid amide, stearic acid amide, oleic acid amide, baxenic acid amide, linoleic acid amide, linolenic acid amide, eleostearic acid amide, arachidic acid amide, eicosadienoic acid amide, medic acid amide, arachidonic acid amide, erucic acid amide, behenic acid amide, methylene bis palmitic amide, methylene bis palmitoleic amide, methylene bismargaric amide, methylene Bistearic acid amide, methylene bisoleic acid amide, methylene bisbakenoic acid amide, methylene bislinoleic acid amide, methylene bislinolenic acid amide, methylene bis-eleostearic acid amide, ethylene bispalmitic acid amide, ethylene bispalmitoleic acid amide, ethylene bismargalinamide, ethylene bisstearic acid amide, ethylene bisoleic acid amide, ethylene bisvalkenoic acid amide, ethylene bislinoleic acid amide, ethylene bislinolenic acid amide, and ethylene bis-eleostearic acid amide. These may be used alone or in combination of two or more.

The grease composition of the present invention contains a thiophosphorus acid compound or a thiophosphoric acid ester compound (d). As long as the effects of the present invention are not impaired, there is no specific limitation on the thiophosphorus acid compound or thiophosphoric acid ester compound (d) used in the present invention. A thiophosphorus acid compound may also be combined with a thiophosphoric acid ester compound.

The thiophosphorus compound or thiophosphoric acid ester compound (d) used in the present invention is preferably a thiophosphorus compound represented by the following formula (5) or a thiophosphoric acid ester compound represented by the following formula (6) to be. When the thiophosphorus compound or the thiophosphoric acid ester compound has one of these structures, a grease composition having much better abrasion resistance and flaking resistance can be obtained.

(R ₈ S) ₃ P (5)

R ₈ represents a saturated or unsaturated hydrocarbon group having 8 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms.

(R ₉ O) ₃ PS (6)

R ₉ represents a saturated or unsaturated hydrocarbon group having 8 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms.

Specific examples of the thiophosphorus acid compound and the thiophosphoric acid ester compound (d) include alkyl thiophosphites such as trilauryl trithiophosphite and aromatic thiophosphates such as triphenyl phosphorothioate. When an alkyl thiophosphite is used, a grease composition having even better abrasion resistance and flaking resistance can be obtained. These may be used alone or in combination of two or more.

The grease composition of the present invention may also contain any of the following components. When the grease composition of the present invention contains a fatty acid or a metal salt thereof (e), or an amine compound (f), better abrasion resistance and flaking resistance can be obtained. When the grease composition of the present invention contains a fatty acid or a metal salt (e) thereof, and an amine compound, even better abrasion resistance and flaking resistance can be obtained.

The grease composition of the present invention may contain a fatty acid or a metal salt (e) thereof. There is no particular limitation on the fatty acid or its metal salt (e) used in the present invention, as long as the effect of the present invention is not impaired. The fatty acid or metal salt thereof used in the present invention is preferably a saturated or unsaturated fatty acid having 4 to 18 carbon atoms, or a metal salt thereof. When the grease composition of the present invention contains a fatty acid or a metal salt (e) thereof, much better abrasion resistance and flaking resistance can be obtained.

Specific examples of fatty acids include butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, capric acid, lauric acid, myristic acid, pendadecylic acid, palmitic acid, margaric acid, stearic acid, crotonic acid, myristoleic acid, palmitoleic acid, sapienoic acid, oleic acid, linoleic acid, linolenic acid, pinolenic acid, eleostearic acid, stearidonic acid, and eicosapentaenoic acid. These may be used alone or in combination of two or more. Since unsaturated fatty acids are more readily adsorbed on the metal surface than saturated fatty acids, they are preferable from the viewpoint of obtaining a grease composition having excellent wear resistance and flaking resistance. As for the number of carbon atoms, a higher number of carbon atoms may be more preferable. Oleic acid is an example of such a fatty acid.

There is no particular limitation on the metal element used to form the salt with these fatty acids, so long as the effect of the present invention is not impaired. Specific examples of the metal element include alkali metals such as lithium, sodium, potassium, rubidium, and cesium; beryllium; magnesium; alkaline earth metals such as calcium, strontium, and barium; aluminum; and zinc. These may be used alone or in combination of two or more. Among them, calcium and aluminum salts are preferable from the viewpoint of obtaining a grease composition having excellent wear resistance and flaking resistance.

The grease composition of the present invention may contain an amine compound (f). There is no restriction on the amine compound (f) used in the present invention as long as the effects of the present invention are not impaired. The amine compound (f) used in the present invention is preferably an amine compound represented by the following formula (2). When the grease composition of the present invention contains such an amine compound, much better abrasion resistance and flaking resistance can be obtained.

R ₄ -NH-R ₅ -NH ₂ (2)

R ₄ represents a saturated or unsaturated hydrocarbon group having 5 to 18 carbon atoms, and R ₅ represents a saturated or unsaturated hydrocarbon group having 2 to 3 carbon atoms.

Specific examples of the amine compound (f) include N-coconut alkyl-1,2-ethylenediamine, N-tallow alkyl-1,2-ethylenediamine, N-cured tallow alkyl-1,2-ethylenediamine, N-coconut Alkyl-1,3-propanediamine, N-tallow alkyl-1,3-propanediamine, N-cured tallow alkyl-1,3-propanediamine, N-coconut alkyl-1,3-propylenediamine, N-tallow tallow Alkyl-1,3-propylenediamine, N-cured tallow alkyl-1,3-propylenediamine, N-coconut alkyl-1,4-butylenediamine, N-tallow alkyl-1,4-butylenediamine, and N-cured tallow alkyl-1,4-butylenediamine. These may be used alone or in combination of two or more. Of these, N-tallow alkyl-1,3-propanediamine is preferred from the viewpoint of obtaining a grease composition having excellent wear resistance and flaking resistance.

The grease composition of the present invention may contain a thickener (other thickener) other than the urea compound in addition to the above-mentioned (urea) thickener. Examples of other thickeners include tricalcium phosphate, alkali metal soaps, alkali metal complex soaps, alkaline earth metal soaps, alkaline earth metal complex soaps, alkali metal sulfonates, alkaline earth metal sulfonates, other metal soaps, terephthalamate metal salts, monourea, polyureas other than triurea monourethane, diurea or tetraurea, clay, silica (silicon oxide) such as silica airgel, and fluororesin such as polytetrafluoroethylene. These may be used alone or in combination of two or more. In addition to these thickeners, any substance capable of providing a viscous effect to the liquid substance may be used. When any of the above-mentioned fatty acids or metal salts (e) thereof are used, the fatty acids or metal salts thereof (e) may be doubled as a thickener. When the fatty acid or metal salt (e) thereof is doubled as a thickener, the amount used may be different from the amount of the fatty acid or metal salt thereof (e) mentioned above.

Without prejudice to the present invention, the grease compositions of the present invention may contain additives such as antioxidants, rust inhibitors, oiliness agents, extreme pressure agents, antiwear agents, solid lubricants, metal deactivators, polymers, non-metal detergents, colorants. , and a water repellent. These may be used alone or in combination of two or more.

Examples of antioxidants are 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butylparacresol, p,p'-dioctyldiphenylamine, N-phenyl-α-naph thylamine, and phenothiazine.

Examples of rust inhibitors include paraffin oxides, carboxylic acid metal salts, sulfonic acid metal salts, carboxylic acid esters, sulfonic acid esters, salicylates, succinates, sorbitan esters, and various amine salts.

Examples of oily agents, extreme pressure agents, and antiwear agents include zinc sulfide dialkyl dithiophosphate, zinc sulfide diallyl dithiophosphate, zinc sulfide dialkyl dithiocarbamate, zinc sulfide diallyl dithiocarbamate, molybdenum sulfide dialkyl Dithiophosphate, molybdenum sulfide diallyl dithiophosphate, molybdenum sulfide dialkyl dithiocarbamate, molybdenum sulfide diallyl dithiocarbamate, organic molybdenum complex, olefin sulfide, triphenyl phosphite, triphenyl phosphorothionate, tri cresine phosphite, other phosphates, and sulfurized oils and fats.

Examples of solid lubricants include molybdenum disulfide, graphite, boron nitride, melamine cyanurate, PTFE (polytetrafluoroethylene), tungsten disulfide, and graphite fluoride. Examples of metal deactivators include N,N'-disalicyllidine-1,2-diaminopropane, benzotriazole, benzimidazole, benzothiazole, and thiadiazole. Examples of the polymer include polybutene, polyisobutene, polyisobutylene, polyisoprene, and polymethacrylate.

One example of a non-metallic detergent is succinimide.

There is no particular limitation on the method used to prepare the grease composition of the present invention. However, the grease composition of the present invention may be prepared by weighing the respective raw materials and mixing them together using any well-known method. As for the amount of optional ingredients to be added, the above-mentioned amounts may be used if necessary.

The amount of the base oil (a) used per 100 mass% of the total grease composition is preferably 70 to 98 mass%, more preferably 75 to 97 mass%, and still more preferably 80 to 95 mass%.

The amount of the diurea compound (b) of the present invention used per 100 mass% of the total grease composition is preferably 1 to 25 mass%, more preferably 3 to 20 mass%, and even more preferably 5 to 15 mass%. %to be. When a thickener other than the diurea compound (b) is added, the total amount of the thickener other than the diurea compound (b) and the diurea compound (b) used per 100 mass% of the total grease composition is preferably 2 to 50 mass% %, more preferably 4 to 40 mass%, and still more preferably 6 to 30 mass%. When the amount of the diurea compound (b) is within this range, the grease composition has a suitable hardness for grease, does not flow off from the lubricating site, has excellent interposition properties on the interface to be lubricated, and achieves the desired lubricating performance. do.

The amount of the amide compound (c) of the present invention used per 100 mass% of the total grease composition is preferably 0.1 to 10 mass%, more preferably 0.2 to 5 mass%, and even more preferably 0.3 to 3 mass%. to be.

The amount of the thiophosphorus acid compound or thiophosphoric acid ester compound (d) of the present invention used per 100 mass% of the total grease composition is preferably 0.1 to 10 mass%, more preferably 0.2 to 5 mass%, and Even more preferably, it is 0.3-3 mass %.

The amount of the fatty acid of the present invention or its metal salt (e) used per 100% by mass of the total grease composition is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, and even more preferably 0.3 to 3% by mass.

The amount of the amine compound (f) of the present invention used per 100 mass% of the total grease composition is preferably 0.1 to 10 mass%, more preferably 0.2 to 5 mass%, and even more preferably 0.3 to 3 mass%. to be.

The amount of any additional additives used per 100 mass % of the total grease composition is preferably 0.1 to 20 mass parts.

The grease composition of the present invention is formulated in Nos. 2 to 0 (265 to 385), preferably Nos. 4 to 00 (175 to 430), more preferably Nos. 3 to 0 (220 to 385). ), and even more preferably in the range of Nos. 2 to 1 (265 to 340). Viscosity indicates the physical hardness of grease. The method used to measure the consistency here follows the "Grease consistency test method" of JIS K2220 7.

The dropping point is not related to the performance of the grease composition of the present invention, but is preferably 180° C. or higher as an indicator that the urea grease thickener structure has reached its original bonding. As the temperature rises, the dropping point is the temperature at which the viscous grease loses its thickener structure. The method used to measure the dropping point is "Grease Dropping Point Test Method" of JIS K2220 8.

The grease compositions of the present invention can of course be used in machinery, bearings, gears, and ball screws where excellent performance as grease lubrication can be exhibited even in harsh environments. Engine peripheral components such as water pumps, cooling fan motors, starters, alternators, and actuators as well as propeller shafts, constant velocity joints (CVTs), powertrain components such as wheel bearings and clutches, electric power steering (EPS) It may be suitable for lubricating various automotive parts including parts, electric power window parts, braking devices, ball joints, door hinges, handle parts, and brake expanders. The grease composition of the present invention preferably slides back and forth in construction machinery such as power shovels, bulldozers, and mobile cranes, steelmaking, papermaking, forestry machinery, agricultural machinery, chemical plants, power generation equipment, and train vehicles. used on shafts and fittings. Other applications include seamless pipe and screw joints for outboard motor bearings. The grease compositions of the present invention are particularly suitable for these applications.

detailed description of the drawings

1 is a schematic diagram showing an overview of the flaking resistance tester. The following parts are marked as shown below:

1: motor

2: axis of rotation

3: crank arm (1)

4: strain gauge

5: crank bent portion

6. Crank Arm (2)

7: Accessory retaining nut

8: main substance

9: Cone accessory part

10: nut

11: collar

12: Bearing fixing block

13: test rolling bearings

14: bearing unit

15: load control device

16: auxiliary rolling bearing

17: swing shaft

Example

The following is a detailed description of the present invention with respect to Examples and Comparative Examples. It should be noted, however, that the present invention is not limited in any way to these examples.

raw material

The following raw material components were used in Examples and Comparative Examples.

base oil (a)

·Base oil A: a mineral oil having a kinematic viscosity of 99.05 mm ² /s at 40°C and a kinematic viscosity of 11.13 mm ² /s at 100°C.

·Base oil B: a mineral oil having a kinematic viscosity of 480.2 mm ² /s at 40°C and a kinematic viscosity of 31.56 mm ² /s at 100°C.

Base oil C: highly with a kinematic viscosity of 43.88 mm ² /s at 40° C., a kinematic viscosity of 7.774 mm ² /s at 100° C., a viscosity index of 146, %CA of 1 or less, %CN of 11.9, and %CP of 85 or more. refined oil.

·Base oil D: a poly α-olefin oil having a kinematic viscosity of 396.5.3 mm ² /s at 40° C. and a kinematic viscosity of 39.99 mm ² /s at 100° C.

Base oil E: an alkyl diphenyl ether oil having a kinematic viscosity of 102.2 mm ² /s at 40° C. and a kinematic viscosity of 12.64 mm ² /s at 100° C.

Diurea compound (b)

Diurea compound (b) was prepared by reacting the following raw materials using the production method described below.

Diurea compound A:

Diphenylmethane-4,4'-diisocyanate (MDI)

octylamine

oleylamine

Diurea compound B:

Diphenylmethane-4,4'-diisocyanate (MDI)

octylamine

Amide compound (c)

Amide compound A: Oleic acid amide (Armoslip CP from Lion Specialty Chemicals)

Thiophosphorus acid compound and thiophosphoric acid ester compound (d)

-Thiophosphorus acid compound A: trilauryltrithiophosphite (JPS-312 from Johoku Chemical)

-Thiophosphoric acid ester compound A:

Triphenylphosphorothioate (Irgalube TPPT from BASF)

Fatty acids or metal salts thereof (e)

Fatty acid A: oleic acid (NAA-35 from NOF)

Fatty Acid Metal Salt A: Calcium Stearate (Calcium Stearate GP from NOF)

Fatty acid metal salt B: aluminum stearate (aluminum stearate 300 from NOF)

amine compound (f)

Amine compound A: N-tallow alkyl-1,3-propanediamine (Lipomin DA-T from Lion Specialty Chemicals)

Example 1

After dissolving the contents by heating the base oil and MDI in the container, octylamine, oleylamine, and the base oil were dissolved, and the raw material mixture prepared by mixing them together was added to the container and reacted to synthesize diurea compound A . The mixture was then heated to 170° C. with stirring, and this temperature was maintained for about 30 minutes to complete the reaction. Thereafter, the mixture was rapidly cooled, and various additives were added during the cooling process in the mixing ratio shown in Table 1, and the obtained mixture was mixed with stirring, cooled to 80° C., and passed through a homogenizer to obtain a grease.

Examples 2 to 18, Comparative Examples 1 to 5

A grease composition was prepared in the same manner as in Example 1, except that the raw materials to be mixed together were those shown in Tables 1 to 4. Diurea compound B was prepared by changing the raw material in diurea compound A to those listed above.

Evaluation of grease composition

The following measurements and tests were performed to compare the properties and performance of Examples and Comparative Examples.

The miscibility and immiscibility of the grease compositions of Examples and Comparative Examples were measured in accordance with JIS K2220 7 "Grease consistency test method". The results are shown in Tables 1-4.

The dropping points of the grease compositions of Examples and Comparative Examples were measured according to "Grease Dropping Point Test Method" of JIS K2220 8. The results are shown in Tables 1-4.

The wear resistance and flaking resistance of the grease compositions of Examples and Comparative Examples were evaluated in bearing flaking and wear tests. The results are shown in Tables 1-4. The following is a description of the evaluation method. 1 is a schematic diagram showing an overview of a bearing flaking and wear tester. A clean test rolling bearing (No. 7205 Angular Contact Ball Bearing) was first weighed, and 3 g of the grease composition was applied to the bearing and loaded into a bearing flaking and wear tester. The nut for the swing shaft was then fixed with a tightening torque of 600 kg·m, and a thrust load was applied to the shaft with a tightening torque. Next, a radial load of 1.0 tons per bearing was applied using a hydraulic piston. The motor was started and the swing shaft reciprocated at 1.7 Hz. After performing the swing operation for 20 hours, the bearings are removed from the apparatus and rinsed with a solvent such as n-hexane to completely remove the grease composition. After measuring the test, the weight of the clean bearing was measured, and the bearing wear amount was obtained by calculating the weight difference compared to the weight of the bearing before the test. After the test, the bearing wear amount, and the area of the sliding surfaces of the outer ring and the inner ring subjected to flaking were measured to evaluate whether the grease composition passed or fell. The pass/fail decision was based on the area where flaking occurred. When the area was less than 50 mm ² , the grease composition passed. When the area was more than that, the grease composition fell off. The area subjected to flaking was determined by observing and specifying the portion in which the flaking occurred under a digital microscope (VHX-6000 from Keyence), and then the area was measured.

Exam conditions

Test Bearing: No. 7205 (Angular Ball Bearing)

Grease amount: 3.0 g

Vibration: 1.7 Hz

Thrust load: 600 Kg·m

Radial load: 1.0 ton

Temperature: 25℃

Time: 20 hours

Evaluation results

Miscibility, dropping point, and bearing flaking and wear tests were performed according to the methods described above. The properties of each grease are shown in Tables 1-4. The grease composition of Examples had the consistency of Nos. 0 to 2, and the grease composition of Comparative Example had the consistency of Nos. 2 and 2.5. At 240 DEG C or higher, the dropping points of the grease compositions of both Examples and Comparative Examples were similar to those of urea grease. Bearing flaking and wear test results are the most important in the present invention, and all of the grease compositions of the present invention passed with a bearing wear amount of less than 150 mg and a total flaking area of less than 50 mm ² . In the case of the grease composition of the comparative example, the bearing wear amount after the bearing flaking and wear test was significant, and the total flaking area on the sliding surfaces of the inner ring and the outer ring exceeded 50 mm ² , indicating that they failed the test.

Claims (6)

base oils (a), diurea compounds (b), amide compounds (c), and thiophosphorous compounds or thiophosphoric acid ester compounds (d) As a grease composition,
The diurea compound (b) includes a compound represented by the formula (1),
R_One-NHCONH-R₂-NHCONH-R₃ (One)
where R_One and R₃represents an acyclic aliphatic hydrocarbon group having 8 to 20 carbon atoms, R₂represents a diphenylmethane group. The method according to claim 1, wherein the diurea compound (b) is an acyclic aliphatic hydrocarbon group having 8 to 12 carbon atoms or an acyclic aliphatic hydrocarbon group having 14 to 20 carbon atoms in Formula 1, wherein R ₁ and R ₃ are A grease composition comprising a diurea compound (b). The grease composition according to claim 1 or 2, further comprising a saturated or unsaturated fatty acid having from 4 to 18 carbon atoms or a metal salt thereof (e). According to any one of claims 1 to 3, further comprising an amine compound (f) represented by the formula (2),
R₄-NH-R₅-NH₂ (2)
where R₄represents a saturated or unsaturated hydrocarbon group having 5 to 18 carbon atoms, R₅represents a saturated or unsaturated hydrocarbon group having 2 to 3 carbon atoms. The amide compound (c) according to any one of claims 1 to 4, wherein the amide compound (c) comprises an amide compound (c) represented by the formula (3) or the formula (4),
R₆-CO-NH₂ (3)
R₆-CO-NH-R₇-NH-CO-R₆ (4)
where R₆represents a saturated or unsaturated hydrocarbon group having 15 to 17 carbon atoms, R₇represents a methylene group or an ethylene group. The thiophosphorus compound according to any one of claims 1 to 5, wherein the thiophosphorus compound comprises a thiophosphorus compound represented by the formula (5), and the thiophosphoric acid ester compound is a thiophosphorus compound represented by the formula (6). a formic acid ester compound;
(R ₈ S) ₃ P (5)
(R ₉ O) ₃ PS (6)
wherein R ₈ represents a saturated or unsaturated hydrocarbon group having 8 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms, R ₉ is a saturated or unsaturated hydrocarbon group having 8 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms.

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