Non-fire-spreading grease composition

Abstract

To provide a non-fire-spreading grease composition with excellent non-flammability and water resistance, and also to provide a bearing or gear containing the non-fire-spreading grease composition.SOLUTION: The non-fire-spreading grease composition according to the present invention comprises the following materials (a) to (d): (a) as a thickening agent, a diurea compound represented by the following formula (1): R1-NHCONH-R2-NHCONH-R3 (1) (wherein R2 represents an aromatic hydrocarbon group having 6 to 15 carbon atoms, and R1 and R3 may be the same or different and represent an aliphatic hydrocarbon group having 8 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 15 carbon atoms, the proportion of aliphatic hydrocarbon groups in the total of R1 and R3 is 50 to 100 mol%); (b) a base oil having a kinematic viscosity of 300 mm2 / s or more at 40°C; (c) at least one selected from the group consisting of rice wax, carnauba wax, and montanic acid derivatives; and (d) at least one selected from the group consisting of organic sulfonic acid metal salts, sodium sebacate, and glycerin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a non-fire-spreading grease composition that can be used for bearings and gears in steelmaking equipment, etc. More specifically, the present invention relates to a non-fire-spreading grease composition that can be used in locations where there is a risk of fire caused by hot scale, etc., that flakes off from the surface during steel processing and scatters, igniting and spreading the fire in the grease, or where water is used during rolling and processing of steel materials. [Background technology]

[0002] Grease is used to lubricate bearings and gears in steelmaking equipment, forging equipment, and other plastic processing equipment. In the steelmaking or rolling equipment used in the steelmaking process, bearings are subjected to high-temperature steel processing, which can cause the grease to soften and leak from the bearings or deteriorate due to the heat. To address these issues, heat-resistant grease is selected and grease is frequently replenished to the bearings using a centralized lubrication system. Furthermore, since water cooling is required for the processing of steel materials in the rolling process, the bearings are also exposed to water. Grease must be water washable so that the grease sealed in the bearings is not washed away by water. Grease also needs to have water-containing shear stability so that it does not soften when subjected to shear forces together with water inside the bearings. Furthermore, fires caused by grease drained from bearings dripping and accumulating below the equipment, which then ignites and spreads when the scattered high-temperature scale comes into contact with the accumulated grease, are becoming a problem. To prevent such fires, it is usually necessary to remove the drained grease. However, grease that has dripped into narrow spaces or in areas that are inaccessible under normal circumstances because they process high-temperature steel, can only be removed during scheduled maintenance when the equipment is stopped. It is difficult to keep the area free of accumulated grease at all times. Even if a fire breaks out, it is easy to extinguish if it is discovered immediately. However, in highly automated facilities, there are fewer personnel, and the fire is not always discovered immediately. If the fire is discovered late, it may become difficult to extinguish, so the grease used is required to have fire-resistant properties to prevent the fire from spreading. Conventional fire-resistant greases use high-viscosity mineral oil as the base oil and lithium soap as the thickener, and are blended with additives that are resistant to thermal decomposition (Non-Patent Document 1). However, lithium grease does not provide sufficient heat resistance for equipment exposed to high temperatures or for the piping that supplies grease to such equipment. For this reason, consideration is being given to switching to urea grease, which has better heat resistance than lithium soap grease.However, with urea grease, the thermal decomposition temperature of the thickener itself is lower than that of lithium soap, making it difficult to make non-fire-spreading grease even when blending base oils and additives that are less likely to evaporate. For example, Patent Document 1 discloses a urea grease for equipment that has load-bearing properties and anti-flame spreading properties. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Lubrication Economy 2016 November Issue No.619 46 [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-030575 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a non-fire-spreading grease composition that is excellent in fire-spreading properties and water resistance. Another object of the present invention is to provide a bearing or gear in which the non-fire-spreading grease composition is packed. [Means for solving the problem]

[0006] 1. (a) A diurea compound represented by the following formula (1) as a thickener: R 1 -NHCONH-R 2 -NHCONH-R 3 (1) (In the formula, R 2 represents an aromatic hydrocarbon group having 6 to 15 carbon atoms, and R 1 and R 3 may be the same or different and represent an aliphatic hydrocarbon group having 8 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 15 carbon atoms; R 1 and R 3 The proportion of aliphatic hydrocarbon groups in the total is 50 to 100 mol %.) (b) Kinematic viscosity at 40°C is 300 mm 2 / s or more base oil, (c) at least one selected from the group consisting of rice wax, carnauba wax, and montanic acid derivatives, and (d) at least one selected from the group consisting of organic sulfonic acid metal salts, sodium sebacate, and glycerin; A non-fire-spreading grease composition comprising: 2. The grease composition according to 1 above, wherein the content of (c) is 0.1 to 2.0 mass % relative to the total mass of the grease composition. 3. The grease composition according to 1 above, wherein the content of (d) is 0.1 to 1.0 mass % relative to the total mass of the grease composition. 4. The grease composition according to 1 above, wherein the metal salt of organic sulfonic acid is a zinc salt or a calcium salt. 5. The grease composition according to 1 above, wherein the content of (a) is 2.5 to 8.0 mass % relative to the total mass of the grease composition. 6.0℃, shear rate 10S -1 2. The grease composition according to 1 above, having an apparent viscosity of 150 Pa·s or less. 7. The grease composition according to 1 above, which is for centralized lubrication. 8. A bearing or gear in which the grease composition according to any one of 1 to 7 above is packed. [Effects of the Invention]

[0007] The urea grease composition of the present invention has excellent fire resistance and water resistance. In a specific embodiment of the present invention, it also has excellent pumpability by centralized lubrication. Although not wishing to be bound by any theory, it is believed that the reason why the grease composition of the present invention has fire-resistant properties can be explained as follows. In other words, even if conventional urea grease contains a base oil containing a high-viscosity mineral oil with a high flash point, it is believed that the thickener thermally decomposes, the generated decomposition gas ignites, and the base oil catches fire, causing combustion. By adding a compound having a functional group such as a sulfonic acid group, a carboxyl group, or a hydroxyl group, such as component (d) of the present invention, the thermal decomposition of the urea thickener is promoted, and the decomposition gas of the thickener, which is the cause of continued combustion, is consumed in the early stages of combustion immediately after ignition, and the supply of decomposition gas decreases as the heat source temperature drops, thereby extinguishing the fire. However, compounds with functional groups such as sulfonic acid groups, carboxyl groups, and hydroxyl groups emulsify grease in the presence of water, promoting the softening of grease by water. In particular, aliphatic urea, which is a thickener, softens when shear is applied in the presence of water. By adding component (c) of the present invention, component (c) protects the urea compound, which acts as a thickener, and prevents the thickener from coming into contact with water, thereby improving water-containing shear stability. Component (c) is a polymeric compound and therefore does not easily ignite. DETAILED DESCRIPTION OF THE INVENTION

[0008] (a) Thickener The thickener used in the present invention is a diurea compound represented by the following formula (1). R 1 -NHCONH-R 2 -NHCONH-R 3 (1) In the formula, R 2 represents an aromatic hydrocarbon group having 6 to 15 carbon atoms, and R 1 and R 3 may be the same or different and represent an aliphatic hydrocarbon group having 8 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 15 carbon atoms; R 1 and R 3 The proportion of the aliphatic hydrocarbon groups in the total is 50 to 100 mol %. The diurea compound is a reaction product of a diisocyanate and a monoamine, and the thickener used in the present invention is - an aliphatic urea compound in which the raw amine is an aliphatic amine, or - Aromatic-aliphatic urea compounds in which the raw amine is a mixture of aromatic amine and aliphatic amine (more specifically, a mixture of aromatic-aromatic urea, aromatic-aliphatic urea, and aliphatic-aliphatic urea, in other words, a mixture of diurea compounds represented by the following formulas (1-1), (1-2), and (1-3) R 1 -NHCONH-R 2 -NHCONH-R 3 (1-1) R 1 -NHCONH-R 2 -NHCONH-R 3 (1-2) R 3 -NHCONH-R 2 -NHCONH-R 3 (1-3) In the formula, R 1 ~R 3 is as defined above.) is. Aromatic-aliphatic urea compounds are more preferred. The diurea compound is represented by the formula (1), R 1 and R 3 may be the same or different and represent an aliphatic hydrocarbon group having 8 to 20 carbon atoms (preferably a linear alkyl group having 8 to 20 carbon atoms, more preferably a linear alkyl group having 8 or 18 carbon atoms) or an aromatic hydrocarbon group having 6 to 15 carbon atoms (preferably an aryl group having 6 or 7 carbon atoms); R 1 and R 3Preferably, the diurea compound has an aliphatic hydrocarbon group content of 50 to 100 mol % of the total of R. 1 and R 3 It is more preferable that the diurea compound has an aliphatic hydrocarbon group content of 70 to 90 mol % of the total of the above. The diurea compound is represented by the formula (1), R 1 and R 3 may be the same or different and represent a linear alkyl group having 8 carbon atoms or an aryl group having 6 carbon atoms, R 2 is a group derived from diphenylmethane-4,4'-diisocyanate, and R 1 and R 3 The most preferred diurea compound is one in which the proportion of linear alkyl groups having 8 carbon atoms in the total of the above is 80 mol %. The thickener content in the composition of the present invention may be any content that achieves the desired consistency depending on the application. For example, when the grease composition of the present invention is used as a grease for centralized lubrication, it is preferably 2.0 to 9.0 mass%, more preferably 2.5 to 8.0 mass%, and even more preferably 3.0 to 8.0 mass%, based on the total mass of the composition. By setting the content within this range, fire resistance, pumpability, and water resistance can be more satisfactorily achieved. When the grease composition is not for centralized lubrication, the content is preferably 6.0 to 17.0 mass%, more preferably 6.0 to 12.0 mass%, and even more preferably 6.0 to 10.0 mass%. By setting the content within this range, water resistance and lubrication life of bearings can be further improved.

[0009] (b) Base oil The base oil used in the present invention has a kinematic viscosity of 300 mm at 40°C. 2 The kinematic viscosity of the base oil of the present invention at 40°C is preferably 300 to 1000 mm 2 / s, more preferably 400 to 550 mm 2 / s. The kinematic viscosity at 40°C is 300mm 2 / s or more, sufficient fire-resistance can be achieved. The base oil can be a mineral oil, a synthetic oil, or a mixture thereof. Examples of mineral oils include paraffinic mineral oils and naphthenic mineral oils. Examples of synthetic oils include ester-based synthetic oils such as diesters and polyol esters; synthetic hydrocarbon oils such as poly-α-olefins and polybutene; ether-based synthetic oils such as alkyl diphenyl ethers and polypropylene glycols; silicone oils; and fluorinated oils. The synthetic oil may also be a so-called biomass oil produced from biological resources derived from animals and plants. For example, biomass ester oils synthesized from various fatty acids and alcohols derived from vegetable oils, or biomass hydrocarbon oils derived from vegetable oils such as palm oil, corn oil, and soybean oil, can also be used. Among these, when the grease composition of the present invention is used as a grease for centralized lubrication, mineral oils are preferred from an economical standpoint. When not for centralized lubrication, synthetic hydrocarbon oils, ester oils, or ether oils are preferred from the standpoint of improving the lubrication life of bearings. When the grease composition of the present invention is used as a grease for centralized lubrication, the base oil content is preferably 75.0 to 97.0 mass%, more preferably 82.0 to 96.0 mass%, which is preferable in terms of pumpability and non-flame spread. The base oil content of the grease composition of the present invention is preferably 70.0 to 93.0 mass %, more preferably 75.0 to 93.0 mass %, when the grease composition is not for centralized lubrication. A base oil content within this range is preferable in terms of pumpability and non-flame spread properties.

[0010] [(c) Rice wax, carnauba wax, montanic acid derivatives] At least one wax selected from the group consisting of rice wax, carnauba wax, and montanic acid derivatives used in the present invention is classified as a wax. In this specification, wax refers to an organic substance having an alkyl group that is solid or semi-solid at room temperature (25°C), melts in a temperature range from 35°C to around 110°C (without dissolving in a base oil), and has a low melt viscosity. Rice wax refers to a wax refined from wax oil separated during the refining of rice bran and rice bran oil, and has a CAS number of 8016-60-2. Rice wax is primarily composed of esters of fatty acids (C16 (approximately 5%), C22 (approximately 20%), C24 (approximately 60%), and the remainder others) with alcohol. Rice wax preferably has an acid value of 10 mg KOH / g or less (e.g., 7 mg KOH / g or less, 5 mg KOH / g or less, or 3 mg KOH / g or less), a saponification value of 70 to 95 mg KOH / g, and a melting point of 77 to 83°C. A saponification value of 80 to 95 mg KOH / g is more preferable for improved flame resistance. Partially saponified rice wax (e.g., the CAS number for Ca partially saponified rice wax is 1850357-57-1) can also be used as the rice wax. The partially saponified rice wax preferably has an acid value of 6 to 15 mgKOH / g or less, a saponification value of 63 to 85 mgKOH / g, and a melting point of 96 to 107°C. The ratio of the fatty acids can be measured by gas chromatography. The acid value can be measured according to ISO 2114. The saponification value can be measured according to ISO 3681. It is preferable to use unsaponified rice wax as the rice wax.

[0011] Carnauba wax refers to wax extracted and refined from the leaves of carnauba palm trees, and its CAS number is 8015-86-9. Carnauba wax is primarily composed of esters of fatty acids (C20 (approximately 7%), C22 (approximately 7%), C24 (approximately 25%), C26 (approximately 10%), C28 (approximately 15%), C30 (approximately 4%), C32 (approximately 6%), and the remainder are others) with alcohol. Carnauba wax preferably has an acid value of 12 mg KOH / g or less, a saponification value of 78 to 95 mg KOH / g, and a melting point of 80 to 86°C. The ratio of the fatty acids can be measured by gas chromatography. The acid value can be measured according to ISO 2114. The saponification value can be measured according to ISO 3681.

[0012] Montanic acid derivatives are waxes derived from montanic acid and are classified as mineral oil-based waxes. They primarily contain long-chain esters and free higher alcohols, resins, sulfur compounds, etc. Examples of such waxes include acid waxes with an acid value of 110 to 160 mgKOH / g, ester waxes with both non-polar and polar moieties, partially saponified ester waxes that are mixtures of montanic acid ester compounds and saponified products with calcium hydroxide, saponified waxes of sodium and calcium salts of montanic acid, and montan waxes to which ethylene oxide has been added. From the viewpoint of heat resistance, the dropping point is preferably 75°C or higher, more preferably 80°C or higher. From the viewpoint of solubility in base oil, the dropping point is preferably 105°C or lower. The acid value is preferably 0 to 160 mgKOH / g, more preferably 0 to 40 mgKOH / g. An acid value within this range is preferred because it minimizes the impact of oxidative degradation of the grease caused by the acid component. Commercially available products include LICOWAX OP FLAKES manufactured by Clariant Japan Co., Ltd.

[0013] Rice wax is preferred as component (c) of the present invention. Unsaponified rice wax is more preferred. Rice wax having a saponification value of 80 to 95 mgKOH / g, particularly unsaponified rice wax, is more preferred. Rice wax having an acid value of 2 to 3 mgKOH / g and a saponification value of 80 to 95 mgKOH / g, particularly unsaponified rice wax, is even more preferred. As described above, component (c) of the present invention protects the urea thickener from water in the grease, improves the grease's water-containing shear stability, and prevents the grease from softening. Rice wax is particularly preferred in terms of pumpability and water-containing shear stability. Two or more types may be used in combination. In this case, it is preferable to use rice wax, particularly unsaponified rice wax. The content of each of rice wax, carnauba wax, and montanic acid derivative is 0.1 to 3.0% by mass, and more preferably 0.1 to 2.0% by mass. Within such ranges, pumpability, fire resistance, and water-containing shear stability are more satisfactory. When two or more types are used in combination, a total content of 0.2 to 2.0% by mass is preferred from the viewpoint of pumpability.

[0014] [(d) organic sulfonic acid metal salt, sodium sebacate, glycerin] As mentioned above, the component (d) of the present invention can extinguish a fire even if the grease catches fire by promoting the thermal decomposition of the thickener urea. Of these, the organic sulfonic acid metal salt is preferred. The organic sulfonate metal salt used in the present invention includes organic sulfonate metal salts such as sodium organic sulfonate, lithium organic sulfonate, barium organic sulfonate, zinc organic sulfonate, and calcium organic sulfonate. Preferred are organic zinc sulfonates and organic calcium sulfonates. As the organic sulfonic acid constituting the organic sulfonate metal salt, alkylsulfonic acid and dinonylnaphthalenesulfonic acid are preferred, and dinonylnaphthalenesulfonic acid is preferred from the viewpoint of non-flammability. Therefore, as the organic sulfonate metal salt of the present invention, zinc alkylsulfonate, calcium alkylsulfonate, zinc dinonylnaphthalenesulfonate, or calcium dinonylnaphthalenesulfonate is particularly preferred. Zinc dinonylnaphthalenesulfonate is particularly preferred.

[0015] When the composition of the present invention contains an organic metal sulfonate, the content thereof is preferably 0.1 to 3.0 mass %, more preferably 0.1 to 1.0 mass %, based on the total mass of the composition, in order to achieve more satisfactory flame resistance and water-containing shear stability.

[0016] When the composition of the present invention contains sodium sebacate, the content thereof is preferably 0.1 to 3.0 mass %, more preferably 0.1 to 1.0 mass %, based on the total mass of the composition, in order to achieve more satisfactory fire resistance and water-containing shear stability.

[0017] When the composition of the present invention contains glycerin, the content thereof is preferably 0.1 to 5.0 mass %, more preferably 0.1 to 1.0 mass %, based on the total mass of the composition, in order to achieve more satisfactory flame resistance and water-containing shear stability. Two or more of these may be used in combination. In this case, it is preferable to use a metal salt of an organic sulfonate, particularly a zinc organic sulfonate or a calcium organic sulfonate, and more particularly a zinc alkylsulfonate, a calcium alkylsulfonate, a zinc dinonylnaphthalenesulfonate, or a calcium dinonylnaphthalenesulfonate. When two or more types are used in combination, it is preferable that the total amount be 0.2 to 1.0 mass % in terms of water-containing shear stability.

[0018] The ratio of component (c) to component (d) is not particularly limited, but for example, a mass ratio of (c):(d) of 3:10 to 5:1 is preferred from the viewpoint of water-containing shear stability, and a ratio of 2:1 to 4:1 is more preferred.

[0019] [Other additives] The grease composition of the present invention may further contain conventional additives such as antioxidants, metal corrosion inhibitors, rust inhibitors, antiwear agents, extreme pressure agents, solid lubricants, or oiliness agents. Examples of antioxidants include phenolic antioxidants and amine antioxidants. Examples of phenolic antioxidants include 2,6-di-tert-butyl-p-cresol (BHT), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol, tert-butylhydroxyanisole (BHA), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 4,4'-methylenebis(2,3-di-tert-butylphenol), and 4,4'-thiobis(3-methyl-6-tert-butylphenol). Examples of the amine antioxidant include Nn-butyl-p-aminophenol, 4,4'-tetramethyl-di-aminodiphenylmethane, α-naphthylamine, N-phenyl-α-naphthylamine, and phenothiazine. Examples of metal corrosion inhibitors include thiadiazoles, benzimidazoles, benzotriazoles, etc. Examples of benzotriazoles include N,N-bis(2-ethylhexyl)-(4 or 5)-methyl-1H-benzotriazole 1-methylamine. Examples of the rust inhibitor include succinic acid derivatives, such as alkenyl succinic anhydride, alkenyl succinic acid ester, and alkenyl succinimide.

[0020] Examples of anti-wear agents and extreme pressure agents include phosphorus-based compounds (tricresyl phosphate, tri-2-ethylhexyl phosphate, etc.), sulfur-based compounds (dibenzyl disulfide, various polysulfides, etc.), sulfur-phosphorus-based compounds (triphenyl phosphorothioate), organometallic extreme pressure agents (dialkyldithiophosphate salts of zinc, molybdenum, tin, bismuth, etc., dialkyldithiocarbamate salts of zinc, molybdenum, tin, nickel, copper, bismuth, etc.), and others (ashless dithiocarbamates). Examples of solid lubricants include organic molybdenum, molybdenum disulfide, graphite, polytetrafluoroethylene, and melamine cyanurate. The oily agent may include higher alcohols, ester oils, etc. The higher alcohol may include stearyl alcohol. The content of such optional additives is, for example, 0.1 to 15.0 mass %, preferably 0.1 to 10.0 mass %, based on the total mass of the composition.

[0021] The grease composition of the present invention is, among others, (a) a mixture of diurea compounds represented by the following formulas (1-1), (1-2), and (1-3) as a thickener; R 1 -NHCONH-R 2 -NHCONH-R 3 (1-1) R 1 -NHCONH-R 2 -NHCONH-R 3 (1-2) R 3 -NHCONH-R 2 -NHCONH-R 3 (1-3) (In the formula, R 2 represents a group derived from diphenylmethane-4,4'-diisocyanate, and R 1 is a linear alkyl group having 8 carbon atoms, and R 3 is an aryl group having 6 carbon atoms, and R 1 and R 3 The proportion of linear alkyl groups having 8 carbon atoms in the total is 80 mol %. (b) Kinematic viscosity at 40°C is 400 to 550 mm 2 mineral oil, (c) rice wax having an acid value of 2 to 3 mg KOH / g and a saponification value of 80 to 95 mg KOH / g; and (d) zinc dinonylnaphthalenesulfonate, A grease composition containing In particular, a grease composition in which the content of (c) is 0.1 to 2.0 mass% relative to the total mass of the grease composition and / or the content of (d) is 0.1 to 1.0 mass% relative to the total mass of the grease composition is preferred.

[0022] [Consistency] The consistency of the grease composition of the present invention is adjusted depending on the intended use, but is preferably 220 to 430, more preferably 280 to 430. When the grease composition of the present invention is used as a centralized lubrication grease for bearings in steelmaking or forging equipment, a consistency of 310 to 385 is preferred from the viewpoints of facilitating pressure-feeding of the grease and preventing grease leakage. When the grease composition of the present invention is used for purposes other than centralized lubrication, a consistency of 265 to 385, more preferably 285 to 365, is preferred from the viewpoints of improving water resistance and lubrication life of the bearings. In this specification, the term "consistency" refers to 60-stroke worked consistency. The consistency can be measured according to JIS K2220 7.

[0023] The composition of the present invention is -1 It is preferable that the apparent viscosity at 150 Pa·s or less. This allows the grease to be pumped smoothly regardless of the outside temperature, especially in cold weather when the fluidity of the grease tends to decrease. The apparent viscosity can be adjusted by the kinematic viscosity of the base oil and / or the amount of thickener.

[0024] The non-fire-spreading grease composition of the present invention can be produced by reacting an amine with an isocyanate in a base oil, followed by heating and dispersing the mixture. Furthermore, additives can be added during the production process. The non-fire-spreading grease composition of the present invention can be used by being enclosed in bearings or gears. In particular, it is suitable for use as a grease composition for centralized lubrication, and is particularly suitable for use as a grease composition for steelmaking equipment. Furthermore, it is preferable to use it by being enclosed in bearings or gears for steelmaking equipment. [Example]

[0025] The ingredients used to prepare the test greases were as follows: (b) Base oil Mineral oil: kinematic viscosity at 40°C: 460mm 2 / s Mineral oil: kinematic viscosity at 40°C: 300mm 2 / s Mineral oil: kinematic viscosity at 40°C: 132mm 2 / s

[0026] (c) Additives Rice Wax A: TOWAX 3F17 (Toa Kasei Co., Ltd.) Acid value 5.4mgKOH / g, saponification value 77.3mgKOH / g, melting point 80.1℃ Rice Wax B: Rice Wax A-1 (Cerarica NODA Co., Ltd.) Acid value 2.6mgKOH / g, saponification value 81.1mgKOH / g, melting point 79.1℃ Ca partially saponified rice wax: LICOCARE RBW300 (Clariant Japan Co., Ltd.) Acid value 11.0mgKOH / g, saponification value 75.0mgKOH / g, melting point 102℃ Carnauba wax: Carnauba WAX2 (Toa Kasei Co., Ltd.) Acid value 11.6mgKOH / g, saponification value 91.2mgKOH / g, melting point 82.3℃ Montanic acid derivative: LICOWAX OP FLAKES (Clariant Japan Co., Ltd.) Acid value 12mgKOH / g, saponification value 112mgKOH / g, melting point 100℃ Lanolin wax: Industrial lanolin TSC (Nippon Fine Chemical Co., Ltd.) Acid value 125mgKOH / g, saponification value 175mgKOH / g, melting point 60℃ Oxidized polyethylene wax: LICOWAX PED522 (Clariant Japan Co., Ltd.) Acid value 25mgKOH / g, melting point 101℃

[0027] (d) Additives ·Organosulfonic acid metal salts Calcium alkylsulfonate: Sulfol Ca-45 (MORESCO Corporation) Zinc dinonylnaphthalene sulfonate: NA-SUL ZS (KING INDUSTRIES) Calcium dinonylnaphthalene sulfonate: NA-SUL 729 (KING INDUSTRIES) Sodium sebacate: IRGACOR DSSG (BASF Japan Ltd.) Glycerin: Seisei Glycerin V (Kao Corporation)

[0028] [Urea grease] In a base oil, 1 mole of diphenylmethane-4,4'-diisocyanate was reacted with 2 moles of aniline and octylamine, and the mixture was heated. During cooling, at least one selected from the group consisting of rice wax, carnauba wax, and montanic acid derivatives was added in the formulation shown in the table below to obtain a base grease. The additives and additional base oil were added to the base grease in the proportions shown in the table to obtain the desired thickener amount, and the mixture was dispersed using a three-roll mill to obtain the grease compositions of the examples and comparative examples. The respective blending proportions are shown in the table below. In the table, the "ratio" for the thickener indicates the molar ratio of aromatic amine (aniline) to aliphatic amine (octylamine), and the other numbers indicate mass % based on the total mass of the composition. The kinematic viscosity of the base oil at 40°C was measured in accordance with JIS K2220 23. The grease compositions obtained above were tested by the following methods. The results are shown in the table below.

[0029] [Lithium soap grease] 12OH stearic acid was dissolved in base oil by heating, and lithium hydroxide dissolved in warm water was added and reacted. The grease was heated until the water in the grease was removed, and then cooled to obtain a base grease. The additives were blended into the base grease, and additional base oil was added to achieve the desired thickener amount. The additives were then added and dispersed using a three-roll mill to prepare a grease composition.

[0030] <Test Method> - Wet roll stability test (based on ASTM D 1831) This test involves applying shear to the grease composition in an environment where moisture has been mixed in. This test was used to evaluate the water-containing shear stability (water resistance) of the grease composition. [Test conditions] Grease content: 45g Ion-exchanged water: 5g Rotation speed: 165 rpm Test temperature: 80℃ Test time: 24 hours [evaluation] ◎: Worked penetration after test: 400 or less ○: Worked penetration after test: 401-415 △: Worked penetration after test: 416 to 439 or less ×: Worked consistency after test: 440 or more (liquefaction)

[0031] Non-fire spread evaluation 100g of the grease composition was placed in a metal container (stainless steel tray) measuring 155mm wide x 126mm long x 27mm deep, and a steel ball (26.98mm in diameter) heated to a specified temperature (950℃) was placed inside, ignited, and burned, and the time from ignition to extinguishing the flame was measured as the burning time. If the burning time exceeded 300 seconds, it was determined that the composition was not fire-resistant, and the fire was extinguished and the test was stopped. [evaluation] ◎: Burning time is less than 150 seconds 〇: Burning time is over 150 seconds and less than 180 seconds △: Burning time is over 180 seconds and less than 300 seconds ×: Continuous combustion for more than 300 seconds

[0032] Pumpability evaluation (JIS K 2220 19.) This test was carried out at 0°C and a shear rate of 10S. -1 This is a test for evaluating the pumpability of a grease composition by measuring the apparent viscosity of the grease composition. [evaluation] ◎: Apparent viscosity is 120 Pa·s or less 〇: Apparent viscosity is over 120 and 150 Pa·s or less ×: Apparent viscosity is over 150 Pa·s

[0033] [Table 1]

[0034] [Table 2]

[0035] [Table 3]

[0036] [Table 4]

Claims

1. (a) a diurea compound represented by the following formula (1) as a thickener: R 1 -NHGNH-R 2 -NHGNH-R 3 (1) (In the formula, R 2 represents an aromatic hydrocarbon group having 6 to 15 carbon atoms, and R 1 and R 3 may be the same or different and represent an aliphatic hydrocarbon group having 8 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 15 carbon atoms; R 1 and R 3 The proportion of aliphatic hydrocarbon groups in the total is 50 to 100 mol %. (b) A kinematic viscosity at 40°C of 300 mm 2 / s or more, (c) at least one selected from the group consisting of rice wax, carnauba wax, and montanic acid derivatives; and (d) at least one selected from the group consisting of organic sulfonic acid metal salts, sodium sebacate, and glycerin; A non-fire-spreading grease composition comprising:

2. 2. The grease composition according to claim 1, wherein the content of (c) is 0.1 to 2.0 mass % relative to the total mass of the grease composition.

3. 2. The grease composition according to claim 1, wherein the content of (d) is 0.1 to 1.0 mass % relative to the total mass of the grease composition.

4. 2. The grease composition according to claim 1, wherein the metal salt of an organic sulfonic acid is a zinc salt or a calcium salt.

5. 2. The grease composition according to claim 1, wherein the content of (a) is 2.5 to 8.0 mass % relative to the total mass of the grease composition.

6. 0°C, shear rate 10S -1 2. The grease composition according to claim 1, having an apparent viscosity of 150 Pa·s or less at 1000 kJ / min.

7. The grease composition according to claim 1, which is for centralized lubrication.

8. A bearing or gear in which the grease composition according to any one of claims 1 to 7 is packed.

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