Non-incendive grease composition

Abstract

The present invention provides a non-incendive grease composition containing (a) a diurea compound represented by the following formula (1) as a thickening agent, (b) a base oil having a kinematic viscosity at 40°C of 300 mm 2 / s or more, (c) at least one selected from the group consisting of rice bran 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. 1 -NHCONH-R 2 -NHCONH-R 3 (1) (in the formula, R 2 represents an aromatic hydrocarbon group having 6 to 15 carbon atoms, 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, the proportion of the aliphatic hydrocarbon group in the total of R 1 and R 3 is 50 to 100 mol%.

Description

Technical Field

[0001] This invention relates to non-flammable grease compositions for bearings and gears in ironmaking equipment, etc. More specifically, this invention relates to non-flammable grease compositions suitable for use in areas where high-temperature oxide scale or other debris flaking off the surface of steel sheets during processing could ignite and spread, potentially causing a fire, or in areas where water is used during the rolling or processing of steel. Background Technology

[0002] Grease is used in the lubrication of bearings and gears in plastic processing equipment such as ironmaking equipment and forging equipment.

[0003] In the steelmaking or rolling process, bearings are processed with steel exposed to high temperatures. As a result, the grease softens due to the heat and leaks from the bearing, or deteriorates due to heat. To address these problems, in addition to selecting heat-resistant greases, grease is frequently replenished to the bearings through centralized grease supply.

[0004] Furthermore, water cooling is required during the steel rolling process, so the bearings will also come into contact with water. To prevent the grease sealed within the bearing from being washed away by water, the grease must be water-resistant. The grease also needs to possess water-content shear stability, meaning it will not soften even when subjected to shearing with water inside the bearing.

[0005] Furthermore, grease discharged from bearings drips and accumulates beneath the equipment. Fires caused by the ignition and spread of grease due to the contact of hot, flying oxide scale with the accumulated grease are considered a problem. To prevent such fires, the discharged grease is usually removed. However, due to grease dripping in confined spaces and in areas normally inaccessible for processing high-temperature steel, grease can only be removed during scheduled maintenance when the equipment is stopped. It is difficult to maintain a consistently grease-free environment.

[0006] In the event of a fire, extinguishing it is relatively easy if it is detected immediately. However, with the increasing automation of equipment, fewer operators may not be able to detect a fire immediately. If the fire is detected late, extinguishing it may become difficult. Therefore, to prevent the spread of combustion in the grease used, non-flame-retardant properties are required. Conventional non-flame-retardant greases use high-viscosity mineral oil as the base oil and lithium soap as the thickener, along with additives that are difficult to decompose thermally (Non-Patent Literature 1). However, for equipment exposed to high temperatures or piping supplying grease to such equipment, lithium grease still cannot meet the required heat resistance.

[0007] Therefore, research is underway to switch to urea greases, which have better heat resistance than lithium soap greases. However, in the case of urea greases, the thickener itself has a lower thermal decomposition temperature than lithium soap, making it difficult to produce non-flammable greases even when combined with base oils and additives that are difficult to evaporate.

[0008] For example, Patent Document 1 discloses a urea grease for equipment that has load-bearing properties and is non-flammable.

[0009] Existing technical documents

[0010] Non-patent literature

[0011] Non-patent literature 1: Lubrication Economics, November 2016, No. 619 46

[0012] Patent documents

[0013] Patent Document 1: Japanese Patent Application Publication No. 2022-030575 Summary of the Invention

[0014] The problem that the invention aims to solve

[0015] The purpose of this invention is to provide a non-flammable grease composition with excellent non-flammability and water resistance.

[0016] Another object of the present invention is to provide a bearing or gear encapsulated with the above-described non-flammable grease composition.

[0017] Methods for solving problems

[0018] 1. A non-flame-retardant grease composition comprising:

[0019] (a) A diurea compound of formula (1) below, used as a thickener.

[0020] R 1 -NHCONH-R 2 -NHCONH-R 3 (1)

[0021] In the formula, R 2 R represents an aromatic hydrocarbon group with 6 to 15 carbon atoms. 1 and R 3 They can be the same or different, representing aliphatic hydrocarbon groups with 8-20 carbon atoms or aromatic hydrocarbon groups with 6-15 carbon atoms. Aliphatic hydrocarbon groups are indicated by R. 1 and R 3 The proportion in the total is 50-100 mol%.

[0022] (b) The kinematic viscosity at 40°C is 300 mm. 2 Base oils with a strength of 0.5 or higher

[0023] (c) Select at least one from the group consisting of rice bran wax, carnauba wax, and lignite acid derivatives, and

[0024] (d) Select at least one from the group consisting of an organic sulfonate metal salt, sodium sebacate, and glycerol.

[0025] 2. The grease composition according to 1 above, wherein the content of (c) is 0.1 to 2.0 by mass relative to the total mass of the grease composition.

[0026] 3. The grease composition according to 1 above, wherein the content of (d) is 0.1 to 1.0 by mass relative to the total mass of the grease composition.

[0027] 4. The grease composition according to claim 1 above, wherein the organic sulfonate metal salt is a zinc salt or a calcium salt.

[0028] 5. The grease composition according to 1 above, wherein the content of (a) is 2.5 to 8.0% by mass relative to the total mass of the grease composition.

[0029] 6. The lubricating grease composition according to claim 1 above, wherein the temperature is 0°C and the shear rate is 10s. -1 The apparent viscosity at that time was below 150 Pa·s.

[0030] 7. The grease composition according to claim 1 above is used for centralized grease supply.

[0031] 8. A bearing or gear having a grease composition as described in any one of 1 to 7 above sealed in.

[0032] Invention Effects

[0033] The urea grease composition of the present invention exhibits excellent non-flammability and water resistance. A particular aspect of the present invention also demonstrates excellent pressure delivery characteristics based on centralized grease supply.

[0034] While not wishing to be bound by any theory, the reasons for believing that the grease composition of the present invention has non-flame-retardant properties are as follows.

[0035] That is, it is believed that in the past, even if the base oil was combined with high-viscosity mineral oil with a high flash point, the thickener in urea grease would undergo thermal decomposition, and the decomposition gas produced would ignite, igniting the base oil and thus causing combustion.

[0036] By adding a compound with functional groups such as sulfonic acid group, carboxyl group, and hydroxyl group, as component (d) of the present invention, the thermal decomposition of urea as a thickener is promoted, so that the decomposition gas of the thickener, which is the cause of continued combustion, is consumed in the initial stage of combustion after ignition. When the heat source temperature decreases, the supply of decomposition gas is reduced, thereby extinguishing the fire.

[0037] However, compounds with functional groups such as sulfonic acid groups, carboxyl groups, and hydroxyl groups emulsify greases in the presence of water, promoting water-induced softening of the grease. In particular, aliphatic ureas, used as thickeners, soften in the presence of water through shearing.

[0038] By incorporating component (c) of the present invention, which protects the urea compound as a thickener, the aqueous shear stability can be improved by inhibiting the contact between the thickener and water.

[0039] (c) The components are high molecular compounds, so they are not easy to ignite. Detailed Implementation

[0040] (a) Thickener

[0041] The thickener used in this invention is a diurea compound represented by the following formula (1).

[0042] R 1 -NHCONH-R 2 -NHCONH-R 3 (1)

[0043] In the formula, R 2 R represents an aromatic hydrocarbon group with 6 to 15 carbon atoms. 1 and R 3 They can be the same or different, representing aliphatic hydrocarbon groups with 8-20 carbon atoms and aromatic hydrocarbon groups with 6-15 carbon atoms. Aliphatic hydrocarbon groups are indicated by R... 1 and R 3 The proportion of 50 to 100 moles in the total is 50 to 100 moles.

[0044] The diurea compound is a reaction product of diisocyanate and monoamine. The thickener used in this invention is:

[0045] - The amine in the raw material is an aliphatic amine or an aliphatic urea compound; or

[0046] - The amine of the raw material is an aromatic-aliphatic urea compound, which is a mixture of aromatic amines and aliphatic amines (more specifically, a mixture of aromatic-aromatic ureas, aromatic-aliphatic ureas and aliphatic-aliphatic ureas, in other words, a mixture of diurea compounds as shown in formulas (1-1), (1-2), and (1-3) below:

[0047] R 1-NHCONH-R 2 -NHCONH-R 3 (1-1)

[0048] R 1 -NHCONH-R 2 -NHCONH-R 3 (1-2)

[0049] R 3 -NHCONH-R 2 -NHCONH-R 3 (1-3)

[0050] in the formula, R 1 R 3 as described above.

[0051] More preferably, the aromatic-aliphatic urea compound.

[0052] For the diurea compound, 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 straight-chain alkyl group having 8 to 20 carbon atoms, more preferably a straight-chain 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) and the proportion of the aliphatic hydrocarbon group in the total of R 1 and R 3 is 50 to 100 mol% of the diurea compound. More preferably, the proportion of the aliphatic hydrocarbon group in the total of R 1 and R 3 is 70 to 90 mol% of the diurea compound.

[0053] For the diurea compound, R 1 and R 3 may be the same or different and represent a straight-chain 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 the proportion of the straight-chain alkyl group having 8 carbon atoms in the total of R 1 and R 3 is 80 mol% of the diurea compound.

[0054] The content of the thickening agent in the composition of the present application can be any content that gives the desired consistency according to the use, for example, in the case where the grease composition of the present application is used as a centralized feeding grease, it is preferably 2.0 to 9.0 mass%, more preferably 2.5 to 8.0 mass%, further preferably 3.0 to 8.0% based on the total mass of the composition. By setting the content to such a range, non-flammability, pressure feeding property and water resistance can be further satisfied. In the case where it is not used for centralized feeding, it is preferably 6.0 to 17.0 mass%, more preferably 6.0 to 12.0 mass%, further preferably 6.0 to 10.0 mass%. By setting the content to such a range, water resistance and lubrication life of the bearing can be further improved.

[0055] [(b) base oil]

[0056] The base oil used in the present application has a kinematic viscosity at 40°C of 300 mm 2 / s or more. The base oil of the present application preferably has a kinematic viscosity at 40°C of 300 to 1000 mm 2 / s, more preferably 400 to 550 mm 2 / s. If the kinematic viscosity at 40°C is 300 mm 2 / s or more, sufficient non-flammability can be exhibited.

[0057] As the base oil, mineral oil, synthetic oil or a mixture thereof can be used. As the mineral oil, paraffin-based mineral oil, naphthenic-based mineral oil and the like can be mentioned. As the synthetic oil, ester-based synthetic oil such as diester, polyol ester, synthetic hydrocarbon oil such as poly-alpha olefin, polybutene, ether-based synthetic oil such as alkyl diphenyl ether, polypropylene glycol, silicone oil, fluorinated oil and the like can be mentioned. Note that the synthetic oil can be so-called biomass oil which is produced using biological resources such as plants and animals as raw materials. For example, biomass ester oil which is synthesized using various fatty acids derived from plant oil as raw materials, biomass hydrocarbon oil which uses plant oil such as palm oil, corn oil, soybean oil and the like can be used. Among them, in the case where the grease composition of the present application is used as a centralized feeding grease, from the viewpoint of economy, mineral oil is preferred. In the case where it is not used for centralized feeding, from the viewpoint of improving the lubrication life of the bearing, synthetic hydrocarbon oil, ester oil or ether oil is preferred.

[0058] In the case where it is used as a centralized feeding grease, the content of the base oil in the grease composition of the present application is preferably 75.0 to 97.0 mass%, more preferably 82.0 to 96.0%. The content of the base oil is preferably in such a range from the viewpoint of pressure feeding property and non-flammability.

[0059] The content of the base oil in the grease composition of the present application is preferably 70.0 to 93.0 mass% and more preferably 75.0 to 93.0% in the case where the grease composition is not used for centralized lubrication. The content of the base oil is preferably in such a range from the viewpoint of pressure feedability and non-flammability.

[0060] [(c) Rice bran wax, carnauba wax, montanic acid derivative]

[0061] At least one selected from the group consisting of rice bran wax, carnauba wax, and montanic acid derivative used in the present application is classified as a wax.

[0062] In the present specification, a wax refers to an organic substance having an alkyl group that is solid or semi-solid at normal temperature (25°C) and melts (i.e., does not dissolve in a base oil) in a temperature range from 35°C to around 110°C, with low melt viscosity.

[0063] Rice bran wax refers to a wax obtained by refining wax oil separated during refining of rice bran and rice oil, and has a CAS number of 8016-60-2. The main component of rice bran wax is an ester of fatty acid (C16 (about 5%), C22 (about 20%), C24 (about 60%), and the remainder is other) and alcohol. The rice bran wax preferably has an acid value of 10 mgKOH / g or less (e.g., 7 mgKOH / g or less, 5 mgKOH / g or less, 3 mgKOH / g or less) and a saponification value of 70 to 95 mgKOH / g and a melting point of 77 to 83°C. More preferably, the saponification value is 80 to 95 mgKOH / g, and the non-flammability is improved. As the rice bran wax, a partially saponified rice bran wax (e.g., Ca partially saponified rice bran wax, which has a CAS number of 1850357-57-1) can be used. The partially saponified rice bran wax preferably has an acid value of 6 to 15 mgKOH / g or less and a saponification value of 63 to 85 mgKOH / g and a melting point of 96 to 107°C. Note that the ratio of the above fatty acid can be determined by gas chromatography analysis. In addition, the acid value can be determined by ISO 2114. The saponification value can be determined by ISO 3681. As the rice bran wax, an unsaponified rice bran wax is preferably used.

[0064] Carnauba wax is a wax obtained from the leaves of palm trees and refined, with CAS number 8015-86-9. The main components of carnauba wax are 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 being other components) and alcohols. Carnauba wax preferably has an acid value below 12 mg KOH / g, a saponification value of 78-95 mg KOH / g, and a melting point of 80-86℃. It should be noted that the ratios of the above fatty acids can be determined by gas chromatography. Additionally, the acid value can be determined according to ISO 2114, and the saponification value can be determined according to ISO 3681.

[0065] Lignite acid derivatives are waxes derived from lignite acid and are classified as mineral oil-based waxes. Long-chain esters mainly include free higher alcohols, resins, and sulfur compounds. Examples include acid waxes with an acid value of 110-160 mg KOH / g, ester waxes possessing both non-polar and polar portions, partially saponified ester waxes (a mixture of ester compounds of lignite acid and saponified calcium hydroxide), saponified waxes of sodium and calcium salts of lignite acid, and lignite waxes with added ethylene oxide. From the viewpoint of heat resistance, a dropping point of 75°C or higher is preferred, more preferably 80°C or higher. From the viewpoint of solubility in base oils, a dropping point of 105°C or lower is preferred. An acid value of 0-160 mg KOH / g is preferred, more preferably 0-40 mg KOH / g. If the acid value is within this range, the acid component has a smaller impact on the oxidative deterioration of the grease, and is therefore preferred. Commercially available examples include LICOWAX OP FLAKES manufactured by Clariant Japan Co., Ltd.

[0066] As component (c) of the present invention, rice bran wax is preferred. Unsaponified rice bran wax is more preferred. Rice bran wax with a saponification value of 80-95 mg KOH / g is even more preferred, particularly unsaponified rice bran wax. Rice bran wax with an acid value of 2-3 mg KOH / g and a saponification value of 80-95 mg KOH / g is even more preferred, particularly unsaponified rice bran wax. As described above, component (c) of the present invention protects the urea thickener in the grease from the influence of water, improves the water-content shear stability of the grease, and prevents the grease from softening. Rice bran wax is particularly preferred in terms of pumpability and water-content shear stability.

[0067] Two or more types can also be used together. In this case, it is preferable to include rice bran wax, especially unsaponifiable rice bran wax.

[0068] The contents of rice bran wax, carnauba wax, and lignite acid derivatives are 0.1~3.0% by mass, more preferably 0.1~2.0% by mass. Within this range, it is possible to further satisfy the requirements for pressurization performance, non-flammability, and water-content shear stability. When two or more are used together, if the total content is 0.2~2.0% by mass, pressurization performance is preferred.

[0069] [(d) Organic sulfonate metal salts, sodium sebacic acid, glycerol]

[0070] As described above, component (d) of the present invention can extinguish fires even if the grease catches fire by promoting the thermal decomposition of urea as a thickener. Preferably, an organosulfonic acid metal salt is used.

[0071] Examples of organic sulfonate metal salts used in this invention include organic sulfonate sodium, organic sulfonate lithium, organic sulfonate barium, organic sulfonate zinc, or organic sulfonate calcium.

[0072] The preferred materials are zinc organic sulfonate and calcium organic sulfonate.

[0073] As the organic sulfonic acid constituting the organosulfonic acid metal salt, alkyl sulfonic acids and dinonylnaphthalene sulfonic acid are preferred, and from the viewpoint of non-flame-retardant properties, dinonylnaphthalene sulfonic acid is preferred. Therefore, as the organosulfonic acid metal salt of the present invention, zinc alkyl sulfonate, calcium alkyl sulfonate, zinc dinonylnaphthalene sulfonate, or calcium dinonylnaphthalene sulfonate are particularly preferred. Zinc dinonylnaphthalene sulfonate is particularly preferred.

[0074] When the composition of the present invention contains an organosulfonic acid metal salt, its content is preferably 0.1 to 3.0% by mass, more preferably 0.1 to 1.0% by mass, based on the total mass of the composition. Within this range, non-flammability and water-containing shear stability are further satisfied.

[0075] When the composition of the present invention contains sodium sebacic acid, its content is preferably 0.1 to 3.0% by mass, more preferably 0.1 to 1.0% by mass, based on the total mass of the composition. Within this range, the non-flammability and water-containing shear stability are further satisfied.

[0076] When the composition of the present invention contains glycerol, the content is preferably 0.1 to 5.0% by mass, more preferably 0.1 to 1.0% by mass, based on the total mass of the composition. Within this range, non-flammability and water-containing shear stability are further satisfied.

[0077] Two or more can also be used together. In this case, it is preferable to include an organosulfonate metal salt, particularly zinc organosulfonate or calcium organosulfonate, and more particularly zinc alkylsulfonate, calcium alkylsulfonate, zinc dinonylnaphthalenesulfonate or calcium dinonylnaphthalenesulfonate.

[0078] When two or more are used together, if the total amount is 0.2 to 1.0% by mass, it is preferred in terms of water-containing shear stability.

[0079] The ratio of component (c) to component (d) is not particularly limited. For example, a mass ratio of (c):(d) of 3:10 to 5:1 is preferred in terms of water-containing shear stability. A ratio of 2:1 to 4:1 is more preferred.

[0080] [Other Additives]

[0081] The grease composition of the present invention may further contain conventional additives, such as antioxidants, metal corrosion inhibitors, rust inhibitors, wear-resistant agents, extreme pressure agents, solid lubricants, or oiliness agents.

[0082] 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 amine-based antioxidants include N-n-butyl-p-aminophenol, 4,4'-tetramethyl-di-aminodiphenylmethane, α-naphthylamine, N-phenyl-α-naphthylamine, and phenothiazine.

[0083] Examples of metal corrosion inhibitors include thiadiazole, benzimidazole, and benzotriazole series. Examples of benzotriazole series include N,N-bis(2-ethylhexyl)-(4 or 5)-methyl-1H-benzotriazole-1-methylamine.

[0084] Examples of rust inhibitors include succinic acid derivatives. Examples of succinic acid derivatives include alkenyl succinic anhydride, alkenyl succinate, and alkenyl succinimide.

[0085] Examples of wear-resistant and extreme pressure agents include phosphorus compounds (tricresyl phosphate, tri-2-ethylhexyl phosphate, etc.), sulfur compounds (dibenzyl disulfide, various polysulfides, etc.), sulfur-phosphorus compounds (triphenyl thiophosphate), organometallic extreme pressure agents (zinc, molybdenum, tin, bismuth, etc. salts of dialkyl dithiophosphate, zinc, molybdenum, tin, nickel, copper, bismuth, etc. salts of dialkyl dithiocarbamate), and others (ashless dithiocarbamates).

[0086] Examples of solid lubricants include organic molybdenum, molybdenum disulfide, graphite, polytetrafluoroethylene, and melamine cyanurate.

[0087] Examples of oiling agents include higher alcohols and ester oils. Examples of higher alcohols include stearyl alcohol.

[0088] The content of such arbitrary additives is based on the total mass of the composition, for example, 0.1 to 15.0% by mass, preferably 0.1 to 10.0% by mass.

[0089] As the lubricating grease composition of the present invention, it preferably contains:

[0090] (a) A mixture of diurea compounds represented by the following formulas (1-1), (1-2), and (1-3) as thickeners.

[0091] R 1 -NHCONH-R 2 -NHCONH-R 3 (1-1)

[0092] R 1 -NHCONH-R 2 -NHCONH-R 3 (1-2)

[0093] R 3 -NHCONH-R 2 -NHCONH-R 3 (1-3)

[0094] In the formula, R 2 R represents a group derived from diphenylmethane-4,4'-diisocyanate. 1 R is a straight-chain alkyl group with 8 carbon atoms. 3 An aryl group with 6 carbon atoms and a straight-chain alkyl group with 8 carbon atoms in R 1 and R 3 The proportion of the total is 80 mol%.

[0095] (b) The kinematic viscosity at 40°C is 400~550 mmHg. 2 / s of mineral oil,

[0096] (c) Rice bran wax with an acid value of 2-3 mg KOH / g and a saponification value of 80-95 mg KOH / g, and

[0097] (d) Zinc dinonylnaphthalenesulfonate.

[0098] A particularly preferred grease composition is one in which the content of (c) is 0.1 to 2.0% by mass relative to the total mass of the grease composition, and / or the content of (d) is 0.1 to 1.0% by mass relative to the total mass of the grease composition.

[0099] [Concentration]

[0100] The consistency of the grease composition of the present invention is adjusted according to the intended use, preferably 220-430, more preferably 280-430. When the grease composition of the present invention is used as a centralized grease for bearings in steel and forging equipment, a consistency of 310-385 is preferred from the viewpoint of facilitating grease delivery and preventing grease leakage. When the grease composition of the present invention is used for purposes other than centralized grease supply, a consistency of 265-385 is preferred from the viewpoint of improving water resistance and bearing lubrication life, more preferably 285-365. Furthermore, in this specification, the term "consistency" refers to the penetration depth after 60 working cycles. Consistency can be measured according to JIS K22207.

[0101] The composition of the present invention is used at 0°C and a shear rate of 10 s. -1 The apparent viscosity is preferably below 150 Pa·s. This ensures unimpeded grease delivery regardless of external temperature, especially during cold weather when grease fluidity tends to decrease. It should be noted that the apparent viscosity can be adjusted by the kinematic viscosity of the base oil and / or the amount of thickener.

[0102] The non-flame-retardant grease composition of the present invention can be manufactured by reacting an amine with an isocyanate in a base oil and then dispersing it by heating. Furthermore, additives can be added during the manufacturing process.

[0103] The non-flammable grease composition of the present invention can be used in bearings or gears. It is particularly suitable for use as a centralized grease supply composition, and especially suitable for use as a grease composition for ironmaking equipment. Furthermore, it is preferred to use it in bearings or gears for ironmaking equipment.

[0104] Example

[0105] The components used to prepare the test grease are as follows.

[0106] (b) Base oil

[0107] • Mineral oil: Kinematic viscosity at 40°C: 460 mmHg 2 / s

[0108] • Mineral oil: Kinematic viscosity at 40°C: 300 mm³ 2 / s

[0109] • Mineral oil: Kinematic viscosity at 40°C: 132 mm³ 2 / s

[0110] (c) Additives

[0111] • Rice bran wax A: TOWAX 3F17 (Toagosei Co., Ltd.)

[0112] Acid value: 5.4 mgKOH / g; Saponification value: 77.3 mgKOH / g; Melting point: 80.1℃

[0113] • Rice bran wax B: Rice bran wax A-1 (CERARICA NODA Co., Ltd.)

[0114] Acid value: 2.6 mg KOH / g; Saponification value: 81.1 mg KOH / g; Melting point: 79.1℃

[0115] • Ca-partially saponified rice bran wax: LICOCARE RBW300 (Clariant Japan Co., Ltd.)

[0116] Acid value: 11.0 mg KOH / g; Saponification value: 75.0 mg KOH / g; Melting point: 102℃

[0117] • Carnauba wax: Carnauba wax 2 (Toa Kasei Corporation)

[0118] Acid value: 11.6 mgKOH / g; Saponification value: 91.2 mgKOH / g; Melting point: 82.3℃

[0119] • Linaloic acid derivatives: LICOWAX OP FLAKES (Clariant Japan Co., Ltd.)

[0120] Acid value: 12 mg KOH / g, Saponification value: 112 mg KOH / g, Melting point: 100℃

[0121] • Lanolin wax: Industrial grade LANOLIN TSC (Nippon Seika Co., Ltd.)

[0122] Acid value 125 mg KOH / g, saponification value 175 mg KOH / g, melting point 60℃

[0123] • Oxidized polyethylene wax: LICOWAX PED522 (Clariant Japan Co., Ltd.)

[0124] Acid value 25 mg KOH / g, melting point 101℃

[0125] (d) Additives

[0126] • Organic sulfonate metal salts

[0127] Alkyl sulfonate calcium: Sulfol Ca-45 (MORESCO Co., Ltd.)

[0128] Zinc dinonylnaphthalenesulfonate: NA-SUL ZS (KING INDUSTRIES)

[0129] Dinonylnaphthalenesulfonate calcium: NA-SUL 729 (KING INDUSTRIES)

[0130] • Sodium sebacate: IRGACOR DSSG (BASF Japan Co., Ltd.)

[0131] • Glycerin: Refined Glycerin V (Kao Corporation)

[0132] [Urea Grease]

[0133] In a base oil, 2 moles of aniline and octylamine are reacted relative to 1 mole of diphenylmethane-4,4'-diisocyanate. The mixture is then heated, and during cooling, at least one of the following groups of rice bran wax, carnauba wax, and lignite derivatives is added according to the formulation shown in the table below to obtain a base grease.

[0134] The additives and additional base oil were added to the base grease according to the proportions shown in the table to achieve the specified thickening dosage. The mixture was then dispersed using a 3-roll mill to obtain the grease compositions of the examples and comparative examples. The respective formulations are shown in the table below.

[0135] It should be noted that in the table, for thickeners, "ratio" indicates the molar ratio of aromatic amine (aniline) to aliphatic amine (octylamine), and all other figures indicate the mass based on the total mass of the composition.

[0136] It should be noted that the kinematic viscosity of the base oil at 40°C was determined according to JIS K2220 23. The grease composition obtained above was tested using the method shown below. The results are shown in the table below.

[0137] [Lithium soap grease]

[0138] 12OH stearic acid is dissolved in a base oil by heating, and lithium hydroxide dissolved in warm water is added and allowed to react. Heating continues until the water in the grease disappears, and after cooling, a base grease is obtained. Additives are then added to the above base grease in a prescribed thickening amount, and the additives are dispersed using a three-roll mill to prepare a grease composition.

[0139] Test Methods

[0140] ○ Stability test of water-containing rollers (according to ASTM D 1831)

[0141] This test applies shear stress to the grease composition in an environment containing moisture. The test evaluates the water-containing shear stability (water resistance) of the grease composition.

[0142] [Experimental Conditions]

[0143] • Grease filling amount: 45g

[0144] • Ion-exchanged water: 5g

[0145] • Speed: 165 rpm

[0146] • Test temperature: 80℃

[0147] • Test duration: 24 hours

[0148] [evaluate]

[0149] ◎: Working cone penetration after testing: below 400

[0150] 〇: Working cone penetration after test: 401~415

[0151] △: Working cone penetration after testing: below 416~439

[0152] ×: Working cone penetration after testing: 440 or higher (liquefaction)

[0153] ○ Non-flammability evaluation

[0154] 100g of the lubricating grease composition was placed in a metal container (stainless steel tray) measuring 155mm long × 126mm wide × 27mm deep. A steel ball (26.98mm in diameter) heated to a specified temperature (950℃) was placed inside. The mixture was ignited and burned, and the time from ignition to extinguishing was measured as the combustion time. If the combustion time exceeded 300 seconds, the mixture was deemed not to have non-flammability, and the test was terminated by extinguishing the fire.

[0155] [evaluate]

[0156] ◎: Burning time is within 150 seconds

[0157] 〇: Burning time exceeding 150 seconds but within 180 seconds

[0158] △: Burning time exceeds 180 seconds but is within 300 seconds

[0159] ×: Continue burning for more than 300 seconds

[0160] ○ Compressibility evaluation (JIS K 2220 19.)

[0161] The experiment was conducted at 0°C and a shear rate of 10S. -1 The apparent viscosity of the grease composition is measured to evaluate its pumpability.

[0162] [evaluate]

[0163] ◎: Apparent viscosity below 120 Pa·s

[0164] 〇: Apparent viscosity exceeding 120 and below 150 Pa·s

[0165] ×: Apparent viscosity exceeds 150 Pa·s

[0166] [Table 1]

[0167]

[0168] [Table 2]

[0169]

[0170] [Table 3]

[0171]

[0172] [Table 4]

[0173] .

Claims

1. A non-flame-retardant lubricating grease composition comprising: (a) A diurea compound of formula (1) below, used as a thickener. R 1 -NHCONH-R 2 -NHCONH-R 3 (1) In the formula, R 2 R represents an aromatic hydrocarbon group with 6 to 15 carbon atoms. 1 and R 3 They can be the same or different, representing aliphatic hydrocarbon groups with 8-20 carbon atoms or aromatic hydrocarbon groups with 6-15 carbon atoms. Aliphatic hydrocarbon groups are indicated by R. 1 and R 3 The proportion in the total is 50-100 mol%. (b) The kinematic viscosity at 40°C is 300 mm. 2 Base oils with a strength of 0.5% or higher (c) Select at least one from the group consisting of rice bran wax, carnauba wax, and lignite acid derivatives, and (d) Select at least one from the group consisting of an organic sulfonate metal salt, sodium sebacate, and glycerol.

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

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

4. The grease composition according to claim 1, wherein, The metal salts of organic sulfonic acids are zinc or calcium salts.

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

6. The grease composition according to claim 1, wherein, 0℃, shear rate 10s -1 The apparent viscosity at that time was below 150 Pa·s.

7. The grease composition according to claim 1, used for centralized grease supply.

8. A bearing or gear, wherein the grease composition of any one of claims 1 to 7 is contained.

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