Grease composition

Abstract

GREASE COMPOSITION. The present invention relates to a lubricating grease used to lubricate mechanical elements having an alternating sliding sphere interposed between them and maintaining resistance to flaking even under a high load in mechanical elements having an alternating sliding sphere interposed between them. The present invention, therefore, provides a grease composition comprising a base oil (a), a diurea compound (b), an amide compound (c) and a thiophosphorous compound or a thiophosphoric acid ester compound (d), wherein the diurea compound (b) includes a compound represented by Formula (1), R1-NHCONH-R2-NHCONH-R3 (1) wherein R1 and R3 represent an acyclic aliphatic hydrocarbon group having from 8 to 20 carbon atoms, and R2 represents a diphenylmethane group.

Description

1 / 28 “GREASE COMPOSITION” TECHNICAL FIELD OF THE INVENTION

[001] The present invention relates to a grease composition. BACKGROUND OF THE INVENTION

[002] Mechanical elements with an alternating sliding ball interposed between them include linear guides, ball screws, and constant velocity joints, and the environments in which they are used are diverse. Rolling and sliding can occur simultaneously in the mechanical elements, and the lubrication environment can be hostile. Under these conditions, contact between the surfaces of the rolling members can occur easily, and wear or seizure can occur when the contact is significant.

[003] An extreme pressure agent is often added to a lubricant, such as lubricating oil and grease, to prevent wear and seizing and to protect mechanical elements. Well-known extreme pressure agents include sulfur-based extreme pressure agents, phosphorus-based extreme pressure agents, sulfur-phosphorus-based organic compounds, and molybdenum compounds. Among these extreme pressure agents, organic extreme pressure agents have become especially popular as they exhibit excellent extreme pressure performance and are currently widely used in lubricating oil compositions.

[004] For example, document JP200111481A discloses a grease composition for a constant velocity sliding joint comprising a urea thickener, molybdenum sulfide dialkyldithiocarbamate, molybdenum disulfide, a sulfur-phosphorus based extreme pressure agent such as zinc dithiophosphate or thiophosphate, and a fatty acid amide to improve lubricity in wear-prone parts that may cause problems such as abnormal vibrations. According to this document, the occurrence of thrust force Petition 870240002348, dated 09 / 01 / 2024, page 9 / 39 2 / 28 induced wear in a constant velocity joint causes problems such as reduced durability of the constant velocity joint, abnormal vehicle vibration, and deterioration of driving comfort, but the use of the technique disclosed in this patent document reduces wear, suppresses vibration, and improves durability.

[005] Document JP 2003321694A discloses a technique in which a grease composition contains a urea thickener and an organic sulfonate to prevent metal fatigue scaling caused by thinning of an oil film despite attempts to thicken the oil film and to extend the service life from metal fatigue scaling.

[006] Document JP200382374A discloses a technique in which a bearing grease composition contains a urea thickener and a benzotriazole and / or derivative to prevent fatigue scaling of the metal caused by thinning of an oil film despite attempts to thicken the oil film and prolong scaling life.

[007] Document JP2008239687A discloses a technique in which a bearing grease composition contains a urea thickener, an alkyl phosphorothioate compound and an aliphatic amine.

[008] Document JP201725189A discloses a technique in which a grease composition contains a thickener of urea, molybdenum dithiocarbamate, zinc dithiocarbamate and zinc sulfonate to prevent metal-to-metal contact in lubrication even under high speed / high surface pressure conditions and to form and maintain an additive film that reduces friction.

[009] The lubricants and grease compositions in documents JP200111481A, JP2003321694A, JP200382374, JP2008239687 and JP201725189A exhibit good wear resistance and film-forming ability under specific conditions or for specific mechanical elements, but a composition capable of maintaining a stable overall balance between wear resistance and film-forming ability. Petition 870240002348, dated 09 / 01 / 2024, page 10 / 39 3 / 28 Film formation during alternating sliding under various high loads was not provided. In particular, the effects of alternating sliding on scaling under various high loads were not studied and may be insufficient.

[010] In view of this situation, it is an objective of the present invention to maintain and improve the service life of mechanical parts even when the bearing momentarily stops during the reversal of reciprocating sliding, an oil film cannot be sufficiently generated, metal-to-metal contact occurs, and wear due to friction tends to be excessive. It is also an objective of the present invention to form a strong additive film, to stably maintain the film that has already been formed even after repeated operation, and to provide stable lubricating properties. In other words, it is an objective of the present invention to provide a grease composition that can be used to lubricate mechanical elements having a reciprocating sliding sphere interposed between them and to maintain resistance to scaling even under a high load. SUMMARY OF THE INVENTION

[011] As a result of extensive research carried out to achieve the aforementioned objectives, the present inventors have discovered that a grease composition containing an amide compound, a thiophosphorous acid compound or a thiophosphoric acid ester compound and a specific diurea compound can be used in mechanical elements with an alternating sliding sphere interposed between them to improve peel resistance. The present invention is a product of this discovery. Specifically, the present invention is as follows.

[012] Aspect (1) of the present invention is a grease composition comprising a base oil (a), a diurea compound (b), an amide compound (c) and a thiophosphorous compound or a thiophosphoric acid ester compound (d), wherein the diurea compound (b) includes a compound represented by Formula Petition 870240002348, dated 09 / 01 / 2024, p. 11 / 39 4 / 28 (1) R1-NHCONH-R2-NHCONH-R3 (1)

[013] where Ri and R3 represent an acyclic aliphatic hydrocarbon group having 8 to 20 carbon atoms, and R2 represents a diphenylmethane group.

[014] Aspect (2) of the present invention is a grease composition according to aspect (1) of the present invention, wherein the diurea compound (b) includes a diurea compound (b) in which R1 and R3 in Formula 1 are an acyclic aliphatic hydrocarbon group having from 8 to 12 carbon atoms or an acyclic aliphatic hydrocarbon group having from 14 to 20 carbon atoms.

[015] 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 from 4 to 18 carbon atoms or a metallic salt (e) thereof.

[016] Aspect (4) of the present invention is a 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)

[017] where R4 represents a saturated or unsaturated hydrocarbon group having from 5 to 18 carbon atoms and R5 represents a saturated or unsaturated hydrocarbon group having from 2 to 3 carbon atoms.

[018] Aspect (5) of the present invention is a grease composition according to any one of aspects (1) to (4) of the present invention, wherein the amide compound (c) includes an amide compound (c) represented by Formula (3) or Formula (4) R6-CO-NH2 (3) R6-CO-NH-R7-NH-CO-R6 (4)

[019] where R6 represents a saturated or unsaturated hydrocarbon group Petition 870240002348, dated 09 / 01 / 2024, p. 12 / 39 5 / 28 having 15 to 17 carbon atoms and R7 represents a methylene group or an ethylene group; and

[020] Aspect (6) of the present invention is a grease composition according to any one of aspects (1) to (5) of the present invention, wherein the thiophosphorous compound includes a thiophosphorous compound represented by Formula (5) and the thiophosphoric acid ester compound includes a thiophosphoric acid ester compound represented by Formula (6) (R8S)3P (5) (R9O)3PS (6)

[021] where R8 represents a saturated or unsaturated hydrocarbon group having from 8 to 18 carbon atoms or an aryl group having from 6 to 18 carbon atoms, and where R9 represents a saturated or unsaturated hydrocarbon group having from 8 to 18 carbon atoms or an aryl group having from 6 to 18 carbon atoms. BRIEF DESCRIPTION OF THE DRAWINGS

[022] Figure 1 is a diagram showing an overview of a peel resistance tester. DETAILED DESCRIPTION OF THE INVENTION

[023] The present invention is capable of providing a grease composition that can be used to lubricate mechanical elements having an alternating sliding sphere interposed between them and maintain resistance to flaking even under a high load in mechanical elements having an alternating sliding sphere interposed between them.

[024] In the present application, “hydrocarbon group” refers to a group of atoms obtained when some of the hydrogen atoms have been removed from a hydrocarbon.

[025] When the name of a compound appears in this application, the name Petition 870240002348, dated 09 / 01 / 2024, page 13 / 39 6 / 28 includes all isomers of the compound.

[026] In this application, an amine compound that forms a diurea compound described below is referred to as a starting amine compound. A starting amine compound and an amine (f) compound may be the same or different. When the quantity of amine (f) compound is mentioned in this descriptive report, the quantity does not include the starting amine compound.

[027] A grease composition of the present invention comprises a base oil (a), a diurea compound (b), an amide compound (c) and a thiophosphorous compound or a thiophosphoric acid ester compound (d).

[028] The diurea compound (b) in the present invention includes a compound represented by Formula (1) R1-NHCONH-R2-NHCONH-R3 (1)

[029] where Ri and R3 represent an acyclic aliphatic hydrocarbon group having 8 to 20 carbon atoms, and R2 represents a diphenylmethane group.

[030] A diurea compound (b) in the present invention is generally produced by the reaction of an isocyanate with a primary amine (starting amine compound). It should be understood that the morphology of the thickening fibers in a diurea thickener depends on the combination of isocyanate and primary amine (starting amine compound) and that the flow characteristics of the resulting grease composition vary significantly.

[031] It should be understood that an aliphatic urea grease using a diurea compound (b) in Formula 1 as a thickener may be a urea grease composed of an alicyclic amine and an aromatic amine or a urea grease consisting of a mixture of an aliphatic amine and an alicyclic amine and / or aromatic amine, and that these have different flow characteristics. It should also be understood that a grease using a diurea compound (b) in Formula 1 as Petition 870240002348, dated 09 / 01 / 2024, p. 14 / 39 7 / 28 Thickener tends to have excellent intervening properties at a lubrication interface and plays an important role in protecting mechanical elements. It should also be understood that a grease using a diurea compound (b) in Formula 1 as a thickener has good solubility of the base oil and intervenes at the lubrication interface along with the base oil, so that the different flow morphologies of the fibers interact with each other to provide good flow behavior and impart effective lubricity. It should also be understood that these effects are pronounced in an aliphatic urea grease containing an unsaturated aliphatic amine.

[032] It should also be understood that a grease composition of the present invention containing a diurea compound (b), an amide compound (c) and a thiophosphite compound or thiophosphate ester compound (d) has a notable effect on improving anti-scaling performance as described below, and that the addition of a fatty acid or fatty acid salt and an amine compound (f) other than the starting amine compound used to form the diurea compound (b) has the effect of further improving the anti-scaling performance of mechanical elements having an alternating sliding sphere interposed between them.

[033] It should also be understood that this has the effect of thickening the lubricant film due to the improved supply of grease composition to the lubricant interface resulting from the excellent flow characteristics exhibited by the aliphatic diurea thickener in the fluid lubrication range where the reciprocating sliding speed is high and that, in addition to the lubricant film of the diurea compound (b), the synergistic thickening effect with the urea grease due to the flow characteristics of the amide compound (c) and the fatty acid or fatty acid salt (e), as well as adsorption to metal surfaces, further improve wear resistance. It should also be understood that, in the mixed lubrication region and in the boundary lubrication region where the oil film near the endpoint of the reciprocating motion Petition 870240002348, dated 09 / 01 / 2024, page 15 / 39 8 / 28 approaches zero, the thiophosphite compound or thiophosphoric acid ester compound (d) and the amine compound (f) included in the grease composition abundantly supplied to the lubrication interface due to the excellent flow characteristics of the grease are adsorbed onto the metal surfaces and the strong coating formed at the interface due to the tribochemical reaction exhibits good anti-scaling performance.

[034] A grease composition of the present invention contains a base oil (a). There are no particular restrictions on the base oil (a) used in the present invention, provided that the effects of the present invention are not impaired. The base oil (a) may be a mineral oil, a synthetic oil, an animal or vegetable oil, or any mixture thereof. Specific examples are those in Groups 1 to 5 in the American Petroleum Institute (API) base oil categories. The API base oil categories are a broad classification of base oil materials defined by the American Petroleum Institute to create guidelines for lubricating base oils.

[035] There are no particular restrictions on the mineral oils used in the present invention. However, preferred examples include paraffin-based or naphthene-based mineral oils obtained by applying one or more refining means, such as solvent degassing, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment, to a lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil. These may be used alone or in combinations of two or more.

[036] There are no particular restrictions on the types of synthetic oils used in the present invention. However, preferred examples include poly α-olefins (PAO) and synthetic hydrocarbon oils (oligomers). A PAO is a homopolymer or copolymer of α-olefins. An α-olefin is a compound with a C-C double bond. Petition 870240002348, dated 09 / 01 / 2024, p. 16 / 39 9 / 28 at the terminal and specific examples include butene, butadiene, hexene, cyclohexene, methylcyclohexene, octene, nonene, decene, dodecene, tetradecene, hexadecene, octadecene, and eicosene. Examples of synthetic hydrocarbon oils (oligomers) include homopolymers or copolymers of ethylene, propylene, and isobutene. These can be used alone or in combinations of two or more. These compounds can have any isomeric structure as long as they have a C-C double bond at the terminal and can have a branched structure or a linear structure. These structural isomers and positional isomers with double bonds can be used in combinations of two or more. Among these olefins, a linear olefin with 6 to 30 carbon atoms is preferred because the flash point is low when the number of carbon atoms is five or less, and the viscosity is high and the olefin impractical when the number of carbon atoms is 31 or higher.

[037] In the present invention, a gas-to-liquid (GTL) base oil synthesized using the Fischer-Tropsch method to convert natural gas into liquid fuel can be used as base oil (a). Compared to a mineral base oil refined from crude oil, a GTL base oil has a very low sulfur and aromatic content and a very high paraffin component ratio. As a result, it has excellent oxidative stability and very low evaporation loss, making it ideal for use as base oil (a) in the present invention.

[038] The grease composition of the present invention contains a diurea compound (b) represented by Formula (1) R1-NHCONH-R2-NHCONH-R3 (1)

[039] where Ri and R3 represent an acyclic aliphatic hydrocarbon group having from 8 to 20 carbon atoms, and R2 represents a diphenylmethane group.

[040] Ri and R3 can be any acyclic aliphatic hydrocarbon group and can be a linear or branched saturated or unsaturated aliphatic hydrocarbon group. R1 and R3 can have the same structure or different structures. Petition 870240002348, dated 09 / 01 / 2024, page 17 / 39 10 / 28

[041] The diurea compound (b) in the present invention can be obtained using the reaction in Formula (7) below. NCO-R2-OCN + R1-NH2 + R3-NH2 ^ R1-NHCONH-R2-NHCONH-R3 (7)

[042] Ri and R3 are preferably an acyclic aliphatic hydrocarbon group having from 8 to 12 carbon atoms or an acyclic aliphatic hydrocarbon group having from 14 to 20 carbon atoms. More preferably, one of Ri and R3 is an acyclic aliphatic hydrocarbon group having from 8 to 12 carbon atoms and the other is an acyclic aliphatic hydrocarbon group having from 14 to 20 carbon atoms. When Ri and R3 have these structures, a grease composition with even better wear resistance and peel resistance can be obtained.

[043] The diurea compound (b) of the present invention can be used alone or in combinations of two or more.

[044] The grease composition of the present invention contains an amide compound (c). There are no particular restrictions on the amide compound (c) used in the present invention, provided it does not impair the effects of the present invention. A preferred example of an amide compound (c) that can be used in the present invention is an aliphatic amide compound represented by Formula (3) below or an aliphatic bisamide compound represented by Formula (4) below. When the amide compound (c) has one of these structures, a grease composition with even better wear resistance and peel resistance can be obtained. R6-CO-NH2 (3) R6-CO-NH-R7-NH-CO-R6 (4)

[045] In these formulas, R6 represents a saturated or unsaturated hydrocarbon group having 15 to 17 carbon atoms and R7 represents a methylene group or an ethylene group.

[046] Specific examples of aliphatic amide compounds and aliphatic bisamide compounds include palmitic acid amide, palmitoleic acid amide, Petition 870240002348, dated 09 / 01 / 2024, p. 18 / 39 11 / 28 margaric acid amide, stearic acid amide, oleic acid amide, vaccenic acid amide, linoleic acid amide, linolenic acid amide, eleostearic acid amide, arachidic acid amide, eicosadienoic acid amide, mead acid amide, arachidonic acid amide, erucic acid amide, behenic acid amide, methylene bispalmitic acid amide, methylene bispalmitoleic acid amide, methylene bismargaric acid amide, methylene bisstearic acid amide, methylene bisoleic acid amide, methylene bisbacenoic acid amide, methylene bislinoleic acid amide, methylene bislinolenic acid amide, methylene bis-eleostearic acid amide, ethylene bispalmitic acid amide ethylene bispalmitoleic acid, ethylene bismargalinamide, ethylene bisstearic acid amide, ethylene bisoleic acid amide, ethylene bisbacenoic acid amide, ethylene bislinoleic acid amide,Ethylene bislinolenic acid amide and ethylene bis-eleostearic acid amide. These can be used alone or in combinations of two or more.

[047] The grease composition of the present invention contains a thiophosphorous acid compound or a thiophosphoric acid ester compound (d). There are no particular restrictions on the thiophosphorous acid compound or thiophosphoric acid ester compound (d) used in the present invention, provided that the effects of the present invention are not impaired. A thiophosphorous acid compound may also be combined with a thiophosphoric acid ester compound.

[048] The thiophosphorous compound or thiophosphoric acid ester compound (d) used in the present invention is preferably a thiophosphorous compound represented by Formula (5) below or a thiophosphoric acid ester compound represented by Formula (6) below. When the thiophosphorous compound or thiophosphoric acid ester compound has one of these structures, a grease composition with even better wear resistance and peel resistance can be obtained. (R8S)3P (5) Petition 870240002348, dated 09 / 01 / 2024, page 19 / 39 12 / 28

[049] R8 represents a saturated or unsaturated hydrocarbon group having from 8 to 18 carbon atoms or an aryl group having from 6 to 18 carbon atoms. (R9O)3PS (6)

[050] R9 represents a saturated or unsaturated hydrocarbon group having from 8 to 18 carbon atoms or an aryl group having from 6 to 18 carbon atoms.

[051] Specific examples of thiophosphorous acid compounds and thiophosphoric acid ester compounds (d) include alkylthiophosphites such as trilauryl trithiophosphite and aromatic thiophosphates such as triphenylphosphorothioate. When an alkylthiophosphite is used, a grease composition with even better wear resistance and peel resistance can be obtained. These can be used alone or in combinations of two or more.

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

[053] The grease composition of the present invention may contain a fatty acid or a metallic salt thereof. There are no particular restrictions on the fatty acids or metallic salts thereof used in the present invention, provided they do not impair the effects of the present invention. A fatty acid or metallic salt thereof used in the present invention is preferably a saturated or unsaturated fatty acid having from 4 to 18 carbon atoms or a metallic salt thereof. When a grease composition of the present invention contains a fatty acid or a metallic salt thereof, even better wear resistance and flaking resistance can be obtained. Petition 870240002348, dated 09 / 01 / 2024, p. 20 / 39 13 / 28

[054] Specific examples of fatty acids include butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, capric acid, lauric acid, myristic acid, pendadecyl 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 can be used alone or in combinations of two or more. Because unsaturated fatty acids are more readily adsorbed onto metal surfaces than saturated fatty acids, they are preferred from the point of view of obtaining a grease composition with excellent wear resistance and flaking resistance. As for the number of carbons, a higher number of carbon atoms is preferable. Oleic acid is an example of such a fatty acid.

[055] There are no particular restrictions on the metallic element used to form a salt with these fatty acids, provided that the effects of the present invention are not impaired. Specific examples of metallic elements 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 combinations of two or more. Among these, calcium and aluminum salts are preferred from the point of view of obtaining a grease composition with excellent wear resistance and flaking resistance.

[056] The grease composition of the present invention may contain an amine compound (f). There are no restrictions on the amine compound (f) used in the present invention, provided that 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 Formula 2 below. When a grease composition of the present invention contains such an amine compound, wear resistance and Petition 870240002348, dated 09 / 01 / 2024, p. 21 / 39 14 / 28 even better resistance to peeling. R4-NH-R5-NH2 (2)

[057] R4 represents a saturated or unsaturated hydrocarbon group having from 5 to 18 carbon atoms and R5 represents a saturated or unsaturated hydrocarbon group having from 2 to 3 carbon atoms.

[058] Specific examples of amine compounds (f) include N-coco alkyl1,2-ethylenediamine, N-beef tallow alkyl-1,2-ethylenediamine, N-beef tallow alkyl-1,2ethylenediamine, N-coco alkyl-1,3-propanediamine, N-beef tallow alkyl-1,3propanediamine, N-hardened beef tallow alkyl-1,3-propanediamine, N-coco alkyl1,3-propylenediamine, N-coco alkyl-1,3-propylenediamine, N-hardened beef tallow alkyl-1,3-propylenediamine, N-coco alkyl-1,4-butylenediamine, N-hardened beef tallow alkyl-1,4-butylenediamine and N-hardened beef tallow alkyl-1,4butylenediamine. These can be used alone or in combinations of two or more. Among these, bovine N-tallow alkyl-1,3-propanediamine is preferred from the point of view of obtaining a grease composition with excellent wear resistance and flaking resistance.

[059] The grease composition of the present invention may include a thickener other than a urea compound (another thickener) in addition to the thickeners (urea) mentioned above. Examples of other thickeners include tricalcium phosphate, alkali metal soaps, alkali metal compound soaps, alkaline earth metal soaps, alkaline earth metal compound soaps, alkali metal sulfonates, alkaline earth metal sulfonates, other metal soaps, metallic salts of terephthalamate, monourea, polyureas other than triurea monourethane, diurea or tetraurea, clays, silicas (silicon oxide), such as silica aerogel, and fluororesins such as polytetrafluoroethylene. These may be used alone or in combinations of two or more. In addition to these thickeners, any substance that can impart a viscous effect to a liquid substance may be used. Petition 870240002348, dated 09 / 01 / 2024, page 22 / 39 15 / 28 When any of the fatty acids or their metallic salts (e) mentioned above is used, the fatty acid or metallic salt thereof may double as a thickener. When a fatty acid or metallic salt thereof (e) doubles as a thickener, the amount used may differ from the amount of fatty acid or metallic salt thereof (e) mentioned above.

[060] The grease composition of the present invention may include additives such as antioxidants, rust inhibitors, oiliness agents, extreme pressure agents, anti-wear agents, solid lubricants, metal deactivators, polymers, non-metallic detergents, colorants and water repellents, provided that they do not impair the present invention. These may be used alone or in combinations of two or more.

[061] Examples of antioxidants include 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butylparacresol, p,p'-dioctyldiphenylamine, N-phenyl-α-naphthylamine and phenothiazine.

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

[063] Examples of oiliness agents, extreme pressure agents and anti-wear agents include zinc sulfide dialkyl dithiophosphates, zinc sulfide diallyl dithiophosphates, zinc sulfide dialkyl dithiocarbamates, zinc sulfide diallyl dithiocarbamates, molybdenum sulfide dialkyl dithiophosphates, molybdenum sulfide diallyl dithiophosphates, molybdenum sulfide dialkyl dithiocarbamates, molybdenum sulfide diallyl dithiocarbamates, molybdenum sulfide organic complexes, olefin sulfides, triphenyl phosphite, triphenyl phosphorothionate, tricresin phosphite, other phosphates and sulfurized oils and fats.

[064] Examples of solid lubricants include molybdenum disulfide, graphite, boron nitride, melamine cyanurate, PTFE (polytetrafluoroethylene), disulfide Petition 870240002348, dated 09 / 01 / 2024, page 23 / 39 16 / 28 tungsten and fluorinated graphite. Examples of metal deactivators include N,N'-disalicylidene-1,2-diaminopropane, benzotriazole, benzimidazole, benzothiazole, and thiadiazole. Examples of polymers include polybutene, polyisobutene, polyisobutylene, polyisoprene, and polymethacrylate.

[065] An example of a non-metallic detergent is succinimide.

[066] There are no particular restrictions on the method used to produce a grease composition of the present invention. However, a grease composition of the present invention can be produced by weighing each raw material and mixing them using any well-known method. As for the quantities of optional components added, the quantities mentioned above can be used if necessary.

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

[068] The amount of diurea compound (b) in the present invention used per 100% by mass of total grease composition is preferably 1 to 25% by mass, more preferably 3 to 20% by mass, and even more preferably 5 to 15% by mass. When a thickener other than diurea compound (b) is added, the total amount of diurea compound (b) and thickener other than diurea compound (b) used per 100% by mass of the overall grease composition is preferably 2 to 50% by mass, more preferably 4 to 40% by mass, and even more preferably 6 to 30% by mass. When the amount of diurea compound (b) is within this range, the grease composition has the right hardness for a grease, does not run off lubrication points, has excellent intervening properties at lubricated interfaces, and achieves the desired lubrication performance. Petition 870240002348, dated 09 / 01 / 2024, p. 24 / 39 17 / 28

[069] The amount of amide compound (c) in the present invention used per 100% by mass of 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.

[070] The amount of thiophosphorous acid compound or thiophosphoric acid ester compound (d) in the present invention used per 100% by mass of total fat 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.

[071] The amount of fatty acid or metallic salt thereof (e) in the present invention used per 100% by mass of total fat 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.

[072] The amount of amine compound (f) in the present invention used per 100% by mass of total fat 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.

[073] The amount of any additional additive used per 100 parts by mass of the overall grease composition is preferably from 0.1 to 20 parts by mass.

[074] The grease composition of the present invention has a consistency in the range of No. 2 to No. 0 (265 to 385), preferably from No. 4 to No. 00 (175 to 430), more preferably from No. 3 to No. 0 (220 to 385), and even more preferably from No. 2 to No. 1 (265 to 340). Consistency indicates the physical hardness of a grease. The method used to measure consistency in the present document is in accordance with the “grease consistency test method” in JIS K2220 7.

[075] The Drop Point is not relevant to the performance of a Petition 870240002348, dated 09 / 01 / 2024, p. 25 / 39 18 / 28 grease composition of the present invention, but preferably 180 °C or higher as an indicator that a urea grease thickening structure has reached its original binding. As the temperature increases, the dropping point is the temperature at which a viscous grease loses its thickening structure. The method used to measure the dropping point is the “grease dropping point test method” in JIS K2220 8.

[076] The grease composition of the present invention can naturally be used in machines, bearings, gears and ball screws where it can exhibit excellent performance as a grease lubrication even in aggressive environments. It is suitable for lubricating various automotive components, including components involving an engine, such as water pumps, cooling fan motors, starter motors, alternators and actuators, as well as transmission rods, constant velocity joints (CVJs), powertrain components such as wheel bearings and clutches, electric power steering (EPS) components, electric window components, braking devices, ball joints, door hinges, door handle components and brake expanders.A grease composition of the present invention is preferably used in rods and fittings that slide back and forth in construction machinery, such as mechanical shovels, tractors and mobile cranes, in the steel industry, in the paper industry, in forestry machinery, in agricultural machinery, in chemical plants, in power generation equipment and in train cars. Other applications include screw joints for seamless pipes and outboard motor bearings. A grease composition of the present invention is especially suitable for these applications. BRIEF DESCRIPTION OF THE DRAWINGS

[077] Figure 1 is a diagram showing an overview of a peel resistance tester. The following parts are marked as indicated. Petition 870240002348, dated 09 / 01 / 2024, page 26 / 39 19 / 28 below: 1: Engine 2: Geometric axis of rotation 3: Crank arm (1) 4: Voltage meter 5: Double portion of the crank 6: Crank arm (2) 7: Installing the retaining nut 8: Key material 9: Cone fitting portion 10: Nut 11: Necklace 12: Bearing retaining block 13: Test bearing 14: Rolling unit 15: Load control device 16: Auxiliary bearing 17: Swing rod EXAMPLES

[078] What follows is a detailed description of the invention with reference to examples and comparative examples. Note, however, that the present invention is in no way limited to these examples. RAW MATERIAL COMPONENTS

[079] The following raw material components were used in the examples and comparative examples. BASE OILS (A)

[080] · Base oil A: A mineral oil with kinematic viscosity at 40 °C Petition 870240002348, dated 09 / 01 / 2024, p. 27 / 39 20 / 28 of 99.05 mm2 / s and kinematic viscosity at 100 °C of 11.13 mm2 / s.

[081] · Base oil B: A mineral oil with a kinematic viscosity at 40 °C of 480.2 mm2 / s and a kinematic viscosity at 100 °C of 31.56 mm2 / s.

[082] · base oil C: A highly refined oil with a kinematic viscosity at 40 °C of 43.88 mm2 / s, a kinematic viscosity at 100 °C of 7.774 mm2 / s, a viscosity index of 146, % CA of 1 or less, % CN of 11.9 and % CP of 85 or more.

[083] · Base oil D: A poly α-olefin oil with a kinematic viscosity at 40 °C of 396.5 mm2 / s and a kinematic viscosity at 100 °C of 39.99 mm2 / s.

[084] · Base oil E: A diphenyl alkyl ether oil with a kinematic viscosity at 40 °C of 102.2 mm2 / s and a kinematic viscosity at 100 °C of 12.64 mm2 / s. DIUREA COMPOUNDS (B)

[085] Diurea compounds (b) were prepared by reacting the following raw materials using the production method described below.

[086] Diurea Compound A:

[087] Octylamine Diphenylmethane-4,4'-diisocyanate (MDI)

[088] Oleylamine

[089] Diurea Compound B:

[090] Octylamine Diphenylmethane-4,4'-diisocyanate (MDI) AMIDE COMPOUNDS (C)

[091] Amide compound A: oleic acid amide (Armoslip CP from Lion Specialty Chemicals) THIOPHOSPHORIC ACID COMPOUNDS AND THIOPHOSPHORIC ACID ESTER COMPOUNDS (D)

[092] Thiophosphorous acid compound A: Trilauryltrithiophosphite (JPS-312 from Petition 870240002348, dated 09 / 01 / 2024, pp. 28 / 39 21 / 28 Johoku Chemical)

[093] Thiophosphoric acid ester compound A: Triphenylphosphorothioate (Irgalube TPPT from BASF) FATTY ACIDS OR METALLIC SALTS THEREOF (E)

[094] Fatty Acid A: Oleic Acid (NAA-35 of NOF)

[095] Fatty Acid Metallic Salt A: Calcium Stearate (NOF Calcium Stearate GP)

[096] Fatty Acid B Metallic Salt: Aluminum Stearate (NOF Aluminum Stearate 300) AMINE COMPOUNDS (F)

[097] Amine Compound A: N-bovine tallow alkyl-1,3-propanediamine (Lipomin DA-T from Lion Specialty Chemicals) EXAMPLE 1

[098] After heating a base oil and MDI in a container to dissolve the contents, a raw material mixture prepared by dissolving and mixing octylamine, oleamine, and a base oil 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. Afterwards, the mixture was rapidly cooled, various additives were added during the cooling process in the proportions of composition shown in Table 1, and the resulting 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

[099] The grease compositions were prepared in the same manner as Example 1, except that the raw materials mixed were those shown in Tables 1 to 4. Diurea Compound B was prepared by changing the raw materials in Diurea Compound A to those listed above. Petition 870240002348, dated 09 / 01 / 2024, pp. 29 / 39 22 / 28 EVALUATION OF GREASE COMPOSITIONS

[0100] The following measurements and tests were performed to compare the properties and performance of the samples and comparative examples.

[0101] The worked and unworked penetration of the grease compositions in the samples and comparative examples were measured according to the “grease consistency test method” in JIS K2220 7. The results are shown in Tables 1 to 4.

[0102] The dropping point of the grease compositions in the examples and comparative examples were measured according to the “grease dropping point test method” in JIS K2220 8. The results are shown in Tables 1 to 4.

[0103] The wear resistance and flaking resistance of the grease compositions in the examples and comparative examples were evaluated in a bearing wear and flaking test. The results are shown in Tables 1 to 4. A description of the evaluation method follows. Figure 1 is a diagram showing an overview of a bearing wear and flaking tester. The weight of a clean test bearing (angular contact ball bearing No. 7205) was measured beforehand, and 3 g of grease composition were applied to the bearing and loaded into the bearing wear and flaking tester. The oscillating rod nut was then tightened with a tightening torque of 600 kg^m, and a thrust load was applied to the rod by the tightening torque. Then, a hydraulic piston was used to apply a radial load of 1.0 ton per bearing. The motor was switched on, and the oscillating rod was spun at 1.7 Hz.After performing the oscillation operation for 20 hours, the bearing was removed from the device and washed with a solvent such as n-hexane to completely remove the grease composition. The weight of the clean bearing after the test was measured, and the weight difference compared to the weight of the bearing before the test was calculated to obtain the amount of bearing wear. The amount of bearing wear after the test and the area of... Petition 870240002348, dated 09 / 01 / 2024, pp. 30 / 39 23 / 28 sliding surfaces of the inner and outer rings experiencing flaking were measured to assess whether the grease composition passed or failed. The pass / fail decision was based on the area where flaking occurred. When the area was less than 50 mm², the grease composition passed. When the area was larger, the grease composition failed. The area experiencing flaking was determined by observing and specifying the portions where flaking occurred under a digital microscope (Keyence VHX-6000), and then the area was measured. TEST CONDITIONS

[0104] Test bearing: No. 7205 (angular ball bearing)

[0105] Amount of grease: 3.0 g

[0106] Oscillation: 1.7 Hz

[0107] Thrust load: 600 Kg^m

[0108] Radial load: 1.0 ton

[0109] Temperature: 25 °C

[0110] Time: 20 hours EVALUATION RESULTS

[0111] The worked penetration, dropping point, and bearing wear and scaling tests were conducted according to the methods described above. The properties of each grease are shown in Tables 1 to 4. The grease compositions in the examples had a consistency of No. 0 and No. 2, and the grease compositions in the comparative examples had a consistency of No. 2 and No. 2.5. The dropping points of the grease compositions in the examples and in the comparative examples at 240 °C or more were comparable to those of urea greases. The results of the bearing wear and scaling test were the most important for the present invention, and all grease compositions of the present invention passed with a bearing wear of less than 150 mg and a total scaling area of ​​less than 50 mm2. In the case of the grease compositions in the examples Petition 870240002348, dated 09 / 01 / 2024, pp. 31 / 39 24 / 28 comparisons, the amount of bearing wear after the bearing wear and scaling test was significant, and the total scaling area on the sliding surfaces of the inner and outer rings exceeded 50 mm2, meaning they failed the test. TABLE 1 Examples 1 2 3 4 5 θ 7 % by mass of base oil Lubricating Oil A 90.80 90.80 47.00 27.15 24.30 24.30 91.20 Lubricating Oil B 47.00 Lubricating Oil C 27.15 24.30 24.30 Lubricating Oil D 36.20 24.30 24.30 Lubricating Oil E 17.10 17.10 % by mass of diurea compound Diurea Compound A 8.2 8.2 5 8.5 9 8.2 Diurea Compound B 9 % by mass of additives Amide Compound A 0.5 0.5 0.5 0.5 0.5 0.5 0.3 Thiophosphorous Acid Compound A 0.5 0.5 0.5 0.3 Thiophosphoric Acid Ester Compound A 0.5 0.5 0.5 Fatty Acid A Fatty Acid Salt A Fatty Acid Salt B Amine Compound A % by total mass of additive 1.0 1.0 1.0 1.0 1.0 1.0 0.6 % by total mass of compound 100 100 100 100 100 100 100 Base Oil Properties KV 40 °C mm% 99.05 99.05 212.49 134.90 115.89 115.89 99.05 KV 100 °C mm2 / s 11.13 111.3 18.39 16.59 14.56 14.56 11.13 Viscosity Index 97 97 96 132 128 128 97 Grease Properties Unmixed Consistency 265 268 357 283 279 276 266 Mixed Consistency 270 273 362 285 289 286 269 Dropping Point °C >270 >270 >270 >270 >270 >270 >270 >270 Bearing Wear After Test in mg 105.0 123.1 102.6 87.9 90.8 106.7 142.8 Braking Evaluation Approved Approved Approved Approved Approved Approved Approved Petition 870240002348, dated 09 / 01 / 2024, pp. 32 / 39 25 / 28 TABLE 2 Examples θ 10 11 12 13 14 % by mass of base oil Lubricating Oil A 90.80 90.80 90.80 91.20 90.80 90.80 90.80 Lubricating Oil B Lubricating Oil C Lubricating Oil D Lubricating Oil E % by mass of diurea compound Diurea Compound A 8.2 8.2 8.2 8.2 8.2 8.2 8.2 Diurea Compound B % by mass of additives Amide Compound A 0.3 0.3 0.3 0.3 0.3 0.3 0.5 Thiophosphorous Acid Compound A 0.3 0.3 0.3 0.25 Acid ester compound Thiophosphoric Acid A 0.3 0.3 0.3 0.25 Fatty Acid A 0.4 0.4 Fatty Acid Salt A 0.4 Fatty Acid Salt B 0.4 Amine Compound A 0.4 % by total mass of additive 1.0 1.0 1.0 0.6 1.0 1.0 1.0 % by total mass of compound 100 100 100 100 100 100 100 Base Oil Properties KV 40 °C mm2 / s 99.05 99.05 99.05 99.05 99.05 99.05 99.05 KV 100 °C mm2 / s 11.13 11.13 11.13 11.13 11.13 11.13 11,13 Viscosity Index 97 97 97 97 97 97 97 Grease Properties Unmixed Consistency 265 268 270 269 265 274 271 Mixed Consistency 270 273 278 276 271 283 278 Dropping Point °C > 270 > 270 >270 > 270 >270 257 >270 Bearing Wear After Test in mg 132.9 129.4 131.0 149.0 139.2 102.0 125.9 Braking Evaluation Approved Approved Approved Approved Approved Approved Approved Petition 870240002348, dated 09 / 01 / 2024, pp. 33 / 39 26 / 28 TABLE 3 Examples 15 16 17 18 % by mass of base oil Lubricating Oil A 24.46 24.35 24.30 88.00 Lubricating Oil B Lubricating Oil C 24.46 24.35 24.30 Lubricating Oil D 24.46 24.35 24.30 Lubricating Oil E 17.21 17.14 17.10 % by mass of diurea compound Diurea Compound A Diurea Compound B 9 9 9 9 m by mass of additives Amide Compound A 0.2 0.2 0.2 1.5 Thiophosphorous Acid Compound A 0.2 0.2 0.2 Thiophosphoric Acid Ester Compound A 1.5 Fatty Acid A 0.2 0.2 Fatty Acid Salt A 0.2 0.2 Fatty Acid Salt B Amine Compound A 0.2 % by total mass of additive 0.4 0.8 1.0 3.0 % by total mass of compound 100 100 100 100 Base Oil Properties KV 40 °C mm2 / s 115.89 115.89 115.89 99.05 KV 100 °C mm2 / s 14.56 14.56 14.56 11.13 Viscosity Index 128 128 128 97 Grease Properties Unmixed Consistency 276 277 284 289 Mixed Consistency 285 283 293 295 Dropping Point °C >270 > 270 247 > 270 Bearing Wear After Test in mg 131.2 125.0 79.5 95.6. Braking Assessment: Approved, Approved, Approved, Approved. TABLE 4 Petition 870240002348, dated 09 / 01 / 2024, pp. 34 / 39 27 / 28 Comparative Examples 1 2 3 4 5 % by mass of base oil Lubricating Oil A 91.80 91.30 91.30 91.30 90.80 Lubricating Oil B Lubricating Oil C Lubricating Oil D Lubricating Oil E % by mass of diurea compound Diurea Compound A 8.2 8.2 8.2 8.2 8.2 Diurea Compound B m by mass of additives Amide Compound A 0.5 Thiophosphorous Acid Compound A 0.5 0.5 Thiophosphoric Acid Ester Compound A Fatty Acid A Fatty Acid Salt A 0.5 Fatty Acid Salt B Amine Compound A 0.5 % by mass of total additive 0.0 0.5 0.5 0.5 1.0% by total mass of compound 100 100 100 100 100 Base oil properties KV 40 °C mm2 / s 99.05 99.05 99.05 99.05 99.05 KV 100 °C mm2 / s 11.13 11.13 11.13 11.13 11.13 Viscosity index 97 97 97 97 97 Grease properties Unmixed consistency 255 257 256 265 272 Petition 870240002348, dated 09 / 01 / 2024, pages 35 / 39 28 / 28 Consistency (mixed) 266 268 266 268 279 Dropping Point °C > 270 >270 >270 > 270 253 Bearing Wear After Test in mg > 250 193.5 198.8 189.9 188.6 Braking Evaluation Failed Failed Failed Failed Failed Petition 870240002348, dated 09 / 01 / 2024, pages 36 / 39

Claims

1 / 2 CLAIMS 1. Grease composition CHARACTERIZED in that it comprises a base oil (a), a diurea compound (b), an amide compound (c), and a thiophosphorous compound or a thiophosphoric acid ester compound (d), wherein the diurea compound (b) includes a compound represented by Formula (1) R1-NHCONH-R2-NHCONH-R3 (1) wherein R1 and R3 represent an acyclic aliphatic hydrocarbon group having from 8 to 20 carbon atoms, and R2 represents a diphenylmethane group and further comprises an amine compound (f) represented by Formula (2) R4-NH-R5-NH2 (2) wherein R4 represents a saturated or unsaturated hydrocarbon group having from 5 to 18 carbon atoms and R5 represents a saturated or unsaturated hydrocarbon group having from 2 to 3 carbon atoms, where the amount of amine compound (f) used per 100% by mass of the overall composition of the grease is from 0.1 to 10% by mass.

2. Grease composition according to claim 1, CHARACTERIZED in that the diurea compound (b) includes a diurea compound (b) wherein R1 and R3 in Formula 1 are an acyclic aliphatic hydrocarbon group having from 8 to 12 carbon atoms or an acyclic aliphatic hydrocarbon group having from 14 to 20 carbon atoms.

3. Fat composition, according to claim 1 or 2, CHARACTERIZED in that it further comprises a saturated or unsaturated fatty acid having from 4 to 18 carbon atoms or a metallic salt thereof (and).

4. Grease composition, according to any one of claims 1 to 3, CHARACTERIZED in that the amide compound (c) includes an amide compound (c) represented by Formula (3) or Formula (4) R6-CO-NH2 (3) Petition 870250019047, dated 11 / 03 / 2025, page 8 / 11 2 / 2 R6-CO-NH-R7-NH-CO-R6 (4) where R6 represents a saturated or unsaturated hydrocarbon group having from 15 to 17 carbon atoms and R7 represents a methylene group or an ethylene group.

5. A grease composition according to any one of claims 1 to 4, CHARACTERIZED in that the thiophosphorous compound includes a thiophosphorous compound represented by Formula (5), and the thiophosphoric acid ester compound includes a thiophosphoric acid ester compound represented by Formula (6) (R8S)3P (5) (R9O)3PS (6) wherein R8 represents a saturated or unsaturated hydrocarbon group having from 8 to 18 carbon atoms or an aryl group having from 6 to 18 carbon atoms and wherein R9 represents a saturated or unsaturated hydrocarbon group having from 8 to 18 carbon atoms or an aryl group having from 6 to 18 carbon atoms. Petition 870250019047, dated 11 / 03 / 2025, p. 9 / 11

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