JP2017128702A - Grease composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water resistant urea-based grease composition of which the grease structure is hardly broken under used environment where water is mixed with the grease and of which the lubrication life can extend by maintaining a lubrication film stable even when water is mixed with the grease by stirring.SOLUTION: The grease composition is provided that contains: an urea compound as a thickener; a base oil; alkali earth metal salicylate and/or alkali earth metal phenate, as a first component of an additive; metal soap which is metal stearate, as a second component of the additive; and calcium sulfonate and/or zinc naphthenate as a third component of the additive. The grease composition is provided that preferably contains further alkyl organic acid and/or alkyl organic ester. The grease composition is provided in which the urea compound of the thickener is preferably diurea or tetraurelia.SELECTED DRAWING: None

Description

  The present invention relates to a grease composition, and more specifically to a urea grease.

  Conventionally, various urea greases have been proposed depending on the application. For example, Patent Document 1 discloses that a urea-based grease contains 0.2 to 15% by weight of a metal salicylate having a specific structure, and is a water-resistant urea-based grease composition used in an environment in contact with water. Has been proposed. Patent Document 2 discloses a urea grease composition for a constant velocity joint, characterized in that urea grease contains a specific molybdenum dialkyldithiocarbamate, a specific triphenylphosphothioate, and a metal stearate. Things have been proposed.

JP 2000-198994 A JP-A-2005-008745

  Here, mixing of water is not preferable at all for lubrication of grease. For this reason, also in mechanical design, the idea which prevents mixing of the water from the exterior as much as possible is made | formed by the improvement of a seal structure. However, depending on the machine parts, there are many places where water is unavoidable due to the usage environment. For example, various bucket pins, gears or crane sliding parts of construction machinery used outdoors, bearings of various rolling mills of steelworks, wheel bearings and constant velocity joints of automobiles, bearings of water pumps or outboard motors and washing The machine bearings and the like are in an environment where they come into contact with water, and water is often mixed to cause abnormal wear or flaking of machine parts, resulting in damage in many cases. In the above-mentioned Patent Document 1, this is an issue. In a use environment where water is mixed in the grease, the grease structure is difficult to break, and even when water is mixed in the grease by stirring, the water particles are fine. The present invention aims to provide a urea-based grease that exists in a stable state and has a property of maintaining a stable lubricating film. However, there are greases proposed in Patent Documents 1 and 2 that have a satisfactory water-resistant life, but even in this case, there is a problem that the water-resistant lubricating wear performance is insufficient.

  Accordingly, an object of the present invention is to provide a urea-based grease having excellent water-resistant lubrication wear performance while realizing a long water-resistant life.

  As a result of diligent research to achieve the above object, it has been found that the above-mentioned problems can be solved by adding additives of three different components to grease containing urea as a thickener. Was completed.

More specifically, the present invention provides the following [1] to [9].
[1]
As a thickener, a urea compound,
Base oils {e.g. lubricating oils or mixed oils belonging to groups 1 to 5 in the base oil category defined by the American Petroleum Institute (API)},
As the first component of the additive, alkaline earth metal salicylate and / or alkaline earth metal phenate,
As a second component of the additive, metal soap that is a metal stearate,
A grease composition containing calcium sulfonate and / or zinc naphthenate as a third component of the additive.
[2]
The grease composition according to [1], which contains both calcium sulfonate and zinc naphthenate as the third component.
[3]
The grease composition according to [1] or [2], further comprising an alkyl organic acid and / or an alkyl organic acid ester.
[4]
The grease composition according to any one of [1] to [3], wherein the thickener is diurea or tetraurea.
[5]
The grease composition according to any one of [1] to [4], wherein a blending amount of the urea compound is 0.5 to 50 parts by mass with respect to 100 parts by mass of the entire grease composition.
[6]
The grease composition according to any one of [1] to [5], wherein a blending amount of the first component is 0.1 to 10 parts by mass with respect to 100 parts by mass of the entire grease composition.
[7]
The grease composition according to any one of [1] to [6], wherein the BN of the first component is 5 to 600 mgKOH / g.
[8]
The grease composition according to any one of [1] to [7], wherein the blending amount of the second component is 0.1 to 10 parts by mass with respect to 100 parts by mass of the entire grease composition.
[9]
The grease composition according to any one of [1] to [8], wherein a blending amount of the third component is 0.1 to 10 parts by mass with respect to 100 parts by mass of the entire grease composition.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the urea-type grease which has the outstanding water-resistant lubricous abrasion performance, implement | achieving a long water-resistant life.

FIG. 1 is a diagram showing an outline of a water-resistant lubrication life tester.

  The grease composition according to this embodiment is obtained by blending a specific additive with urea grease. Hereinafter, although the specific component of the grease composition according to the present embodiment, the blending amount of each component, the production method, the physical properties, and the use will be described in detail, the present invention is not limited to these.

≪Grease composition (component) ≫
[Base oil]
The base oil used for the grease composition of this embodiment is not particularly limited. For example, mineral oils, synthetic oils, animal and vegetable oils, and mixed oils thereof used in ordinary grease compositions can be appropriately used. Specific examples include those of groups 1 to 5 in the base oil category of API (American Petroleum Institute). Here, the API base oil category is a broad class of base oil materials defined by the American Petroleum Institute to create lubricant base oil guidelines.

  In the present invention, the type of mineral oil is not particularly defined, but as a preferred example, a lubricating oil fraction obtained by subjecting crude oil to atmospheric distillation and vacuum distillation is subjected to solvent removal, solvent extraction, hydrogen List mineral oils such as paraffinic or naphthenic oils obtained by applying a suitable combination of one or more purification methods such as hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment. Can do.

  In the present invention, the type of the synthetic oil is not particularly defined, but a poly α-olefin (PAO) or a hydrocarbon synthetic oil (oligomer) can be mentioned as a preferred example. PAO is an α-olefin homopolymer or copolymer. For example, α-olefin is a compound having a C—C double bond at its terminal, such as butene, butadiene, hexene, cyclohexene, methylcyclohexene, octene, nonene, decene, dodecene, tetradecene, hexadecene, octadecene, eicosene and the like. Illustrated. Examples of the hydrocarbon-based synthetic oil (oligomer) include a homopolymer or a copolymer of ethylene, propylene, or isobutene. These compounds can be used alone or as a mixture of two or more. In addition, these compounds may have any structure of possible isomeric structures as long as the C—C double bond is at the terminal, and may have a branched structure or a linear structure. Two or more of these structural isomers and double bond positional isomers may be used in combination. Among these olefins, the use of straight chain olefins having 6 to 30 carbon atoms is more preferable because the flash point is low at 5 or less carbon atoms and the viscosity is high and the utility is low at 31 or more carbon atoms.

  In the present invention, GTL (Gas Liquid) synthesized by the Fischer-Tropsch method of natural gas liquid fuel technology may be used as the base oil. Since GTL has a very low sulfur content and aromatic content and a very high paraffin composition ratio compared to a mineral base oil refined from crude oil, GTL has excellent oxidation stability and very low evaporation loss. It can be suitably used as a base oil.

[Thickener]
The urea thickener used in the present embodiment is not particularly limited as long as it is a known urea thickener, but preferably a diurea thickener and a monourea obtained by reacting 1 mol of diisocyanate and 2 mol of primary monoamine. Diurea thickener obtained by reacting 2 mol of isocyanate and 2 mol of primary diamine, or tetraurea thickener obtained by reacting 2 mol of diisocyanate with 2 mol of primary monoamine and 1 mol of primary diamine, or 2 mol of diisocyanate and A triurea monourethane thickener obtained by reacting 1 mol of primary monoamine, 1 mol of primary diamine and 1 mol of higher alcohol. More preferred is a diurea or tetraurea thickener. These may be used alone or in combination of two or more.

  Examples of the isocyanate used as a raw material include 4,4′-diphenimethane diisocyanate (MDI), tolylene diisocyanate (TDI), 3,3′-dimethyl-4,4′-biphenylene diisocyanate (TODI), and hexamethylene diisocyanate. (HDI), naphthalene diisocyanate (NDI), octadecyl isocyanate (ODI) and the like. Examples of primary amines include octylamine (caprylamine), isooctylamine, laurylamine, myristylamine, palmitylamine, stearylamine, isostearylamine, behenylamine, oleylamine, linoleylamine, tallow amine, coconut Amine, hydrogenated beef tallow amine, soybean amine, cyclohexylamine, aniline, p-chloroaniline, phenethylamine, o-toluidine, m-toluidine, p-toluidine, 2-naphthylamine and the like can be mentioned. Examples of the diamine include ethylene diamine, trimethylene diamine (propylene diamine), tetramethylene diamine (butylene diamine), pentamethylene diamine, hexamethylene diamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, and the like. Examples of the salts include N-cocoalkyl-1,2-ethylenediamine, N-tallow alkyl-1,2 -Ethylenediamine, N-cured tallow alkyl-1,2-ethylenediamine, N-coconut alkyl-1,3-propylenediamine, N-tallow alkyl-1,3-propylenediamine, N-cured tallowalkyl-1,3-propylenediamine N-coconut alkyl-1, Examples include 4-butylenediamine, N-tallow alkyl-1,4-butylenediamine, N-cured tallow alkyl-1,4-butylenediamine, and the like. Examples of the higher alcohol include lauryl alcohol, cetyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lanolin alcohol, hexyl decanol, octyldodecanol, and isostearyl alcohol.

(Other thickeners)
In the grease composition of this embodiment, a thickener other than the urea compound (other thickeners) may be used together with the above thickener (urea). These other thickeners include tribasic calcium phosphate, alkali metal soaps, alkali metal composite soaps, alkaline earth metal soaps, alkaline earth metal composite soaps, alkali metal sulfonates, alkaline earth metal sulfonates, other metal soaps, Examples include terephthalamate metal salts, monourea, triurea monourethane, polyurea other than diurea or tetraurea, silica (silicon oxide) such as clay and silica airgel, and fluororesin such as polytetrafluoroethylene. 1 type (s) or 2 or more types can be used together. In addition to these, any substance that can impart a viscosity effect to a liquid substance can be used.

[Additive]
The grease composition of this embodiment is obtained by adding specific additives (first component, second component, third component) to the grease containing the above thickener (urea). By adding these additives to the urea-based grease composition, it is possible to achieve both a long-term water-resistant life and excellent water-resistant lubricating wear performance.

(First ingredient)
The first component of the additive used in this form is an alkaline earth metal salicylate and / or an alkaline earth metal phenate.

  First, examples of the alkaline earth metal salicylate include alkali metal salicylates known as metal detergents, and alkaline earth metal salts of alkyl salicylic acid are preferable. Here, as the alkaline earth metal, a magnesium salt and / or a calcium salt is preferable, and a calcium salt is particularly preferable. Moreover, as said alkyl group, a C4-C30 thing is suitable and a C6-C18 linear or branched alkyl group is more suitable. In addition, these may be linear or branched, and may be primary alkyl groups, secondary alkyl groups, or tertiary alkyl groups.

  Next, as the alkaline earth metal phenate, mention may be made of alkali metal salicylates known as metal detergents, including alkaline earth metal salts of Mannich reactants of alkylphenols, alkylphenol sulfides, alkylphenols, especially magnesium salts and And / or calcium salts and the like, and calcium salts are particularly preferred.

  Here, the alkaline earth metal salicylate and / or the alkaline earth metal phenate-based metal detergent has a total base number (BN) defined by JIS K2501 (perchloric acid method) of 5 to 600 mgKOH / The metal detergent which is g is preferable, the metal detergent which is 50 to 500 mgKOH / g is more preferable, and the metal detergent which is 100 to 400 mgKOH / g is still more preferable. If BN is within this range, when water is mixed in the urea grease of the present invention, the grease is more uniformly dispersed in the base oil and the state is more easily maintained, and the grease structure is weakened and softened due to the influence of moisture. In addition, there is an effect of further improving functions such as generation of rust accompanied by free water due to insufficient water dispersibility and reduction in lubricity. The additive component of the metal detergent may comprise a salt of one type of organic acid or a salt of more than one type of organic acid, which is a neutral metal detergent, an overbased metal system. It can be a detergent or a mixture of both.

(Second component)
The second component of the additive used in this embodiment is a metal soap, specifically a metal stearate. Here, examples of the water-insoluble stearic acid metal salt include salts of alkali metal (for example, lithium), alkaline earth metal (for example, magnesium, calcium, barium), aluminum, zinc, etc., and calcium and / or Magnesium salts are particularly preferably used. In addition, you may use the said component in combination of 1 type or multiple types.

(Third component)
The third component of the additive used in this form is calcium sulfonate and / or zinc naphthenate.

  First, calcium sulfonate is a general calcium sulfonate, for example, calcium salt of petroleum sulfonic acid, calcium salt of alkyl aromatic sulfonic acid, overbased calcium salt of petroleum sulfonic acid, overbased of alkyl aromatic sulfonic acid. Calcium salt and the like. The said component can be used individually or in mixture.

  Next, zinc naphthenate is a common zinc naphthenate, for example derived from a selected crude oil fraction, typically by reacting the fraction with a sodium hydroxide solution followed by acidification and purification. And a complex mixture of naphthenic acids. The preferred molecular weight of naphthenic acid before the reaction with the zinc compound is in the range of 150 to 500, more preferably 180 to 330.

[Arbitrary ingredients]
The grease composition of this embodiment further includes an optional antioxidant, rust inhibitor, oiliness agent, extreme pressure agent, antiwear agent, solid lubricant, metal deactivator, polymer, non-metallic detergent, and colorant. In addition, an additive such as a water repellent can be added in an amount of about 0.1 to 20 parts by mass with respect to the entire optional composition, with the total grease composition being 100 parts by mass. For example, as an antioxidant, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butylparacresol, p, p′-dioctyldiphenylamine, N-phenyl-α-naphthylamine And phenothiazine. For example, examples of the rust preventive include oxidized paraffin, carboxylic acid metal salt, sulfonic acid metal salt, carboxylic acid ester, sulfonic acid ester, salicylic acid ester, succinic acid ester, sorbitan ester, various amine salts, and the like. For example, oily agents, extreme pressure agents, and antiwear agents include zinc sulfide dialkyldithiophosphate, zinc sulfide diallyldithiophosphate, zinc sulfide dialkyldithiocarbamate, zinc sulfide diallyldithiocarbamate, sulfide dialkyldithiophosphate molybdenum, sulfide diallyldithiophosphate molybdenum. , Sulfurized dialkyldithiocarbamate molybdate, diallyldithiocarbamate molybdate, organic molybdate complex, sulfurized olefin, triphenyl phosphate, triphenyl phosphorothioate, tricresin phosphate, other phosphate esters, sulfurized oils and fats. Examples of the solid lubricant include molybdenum disulfide, graphite, boron nitride, melamine cyanurate, PTFE (polytetrafluoroethylene), tungsten disulfide, and graphite fluoride. For example, the metal deactivator includes N, N′disalicylidene-1,2-diaminopropane, benzotriazole, benzimidazole, benzothiazole, thiadiazole and the like. For example, examples of the polymer include polybutene, polyisobutene, polyisobutylene, polyisoprene, and polymethacrylate. For example, succinimide etc. can be mentioned as a nonmetallic detergent.

  In particular, the grease composition according to the present embodiment preferably contains an alkyl organic acid and / or an alkyl organic acid ester. Here, the alkyl organic acid or the alkyl organic acid ester is formic acid, acetic acid, propionic acid, butyric acid (butyric acid), isobutyric acid, valeric acid (valeric acid), isovaleric acid, caproic acid, enanthonic acid (heptylic acid). ), Caprylic acid, 2-ethylhexanoic acid, pelargonic acid, trimethylhexanoic acid, capric acid, undecylic acid, lauric acid, Lindelic acid, tridecylic acid, myristic acid, tuzuic acid, fisetreic acid, myristoleic acid, pentadecylic acid, Palmitic acid, palmitoyl acid, margaric acid, stearic acid, isostearic acid, petrothelic acid, elaidic acid, oleic acid, vaccenic acid, linoleic acid, linolenic acid, eleostearic acid, eicosadienoic acid, icosatrienoic acid, stearidonic acid, nonadecylic acid, Tubercrose stearic acid, arachidic acid Arachidonic acid, Paulic acid, Eicosapentaenoic acid, Henocosylic acid, Behenic acid, Erucic acid, Docosapentaenoic acid, Docosahexaenoic acid, Tricosylic acid, Lignoceric acid, Nervonic acid, Serotic acid, Montanic acid, Melicic acid, and / or from these And the ester compound. By containing the said component, it becomes possible to improve water-resistant lubrication wear resistance, ensuring a long water-resistant lubrication life.

≪Grease composition (mixing amount of each component) ≫
Next, the blending amounts of the base oil, the thickener and the additive in the grease composition according to this embodiment will be described. In addition, about the compounding quantity of arbitrary components, what is necessary is just to mix | blend suitably with the above-mentioned compounding quantity, if necessary.

[Base oil]
As a compounding quantity of a base oil, the whole grease composition is 100 mass parts, Preferably it is 50-95 mass parts, More preferably, it is 60-90 mass parts, More preferably, it is 70-85 mass parts.

[Thickener]
The blending amount of the entire thickener is preferably 3 to 50 parts by weight, more preferably 5 to 40 parts by weight, and even more preferably 7 to 30 parts by weight, based on 100 parts by weight of the entire grease composition. . Moreover, the compounding amount of the urea compound is preferably 0.5 to 50 parts by mass with respect to 100 parts by mass of the entire grease composition. If the amount of the urea compound is less than 0.5 parts by mass, it will be difficult to maintain sufficient hardness as grease, and it will be easy to flow out of the lubrication site regardless of the mixing of water. Lubricating performance cannot be demonstrated. On the other hand, when the amount is more than 50 parts by mass, the grease becomes too hard, the supply of the base oil becomes insufficient, and the lubricating performance may be lowered. In addition, the cost increases.

[Additive]
(First ingredient)
The compounding amount of the metal-based detergent that is the alkaline earth metal salicylate and / or alkaline earth metal phenate as the first component as an additive is preferably from 0.1 to 10 mass, based on 100 parts by mass of the entire grease composition Part, more preferably 0.3 to 7 parts by mass, still more preferably 0.5 to 5 parts by mass. If the amount of the metallic detergent is less than 0.1 parts by mass, the hardness of the grease will not change (it will not be softened), but the particles of water mixed in the grease can be sufficiently dispersed. Therefore, it may be difficult to maintain a stable lubricating film. If the amount is more than 10 parts by mass, the dispersibility of water is improved, but the grease tends to soften due to shearing, and it tends to flow out of the lubrication site, so that the intended lubrication performance may not be exhibited. is there.

(Second component)
The blending amount of metal soap, which is a water-insoluble metal stearate as a second component as an additive, is preferably 0.1 to 10 parts by mass, more preferably 0, based on 100 parts by mass of the entire grease composition. 3 to 7 parts by mass, and more preferably 0.5 to 5 parts by mass. If the blending amount of the metal soap is less than 0.1 parts by mass, water mixed in the grease cannot be sufficiently dispersed, and it may be difficult to maintain a stable lubricating film. On the other hand, when the amount is more than 10 parts by mass, the dispersibility of water is improved, but only the cost is increased and no further effect can be expected.

(Third component)
The amount of the third component, calcium sulfonate and / or zinc naphthenate, as the additive is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 7 parts, based on 100 parts by mass of the entire grease composition. It is a mass part, More preferably, it is 0.5-5 mass part. When the amount of these additives is less than 0.1 parts by mass, it may be difficult to exert the above-described effects. When the amount is more than 10 parts by mass, suppression of the occurrence of rust can be expected, Grease tends to soften and flow out due to shear, and it may be difficult to obtain the desired lubricating performance.

≪Physical properties of grease composition≫
[Mixing consistency]
The grease composition of this embodiment preferably has a consistency of No. 00 to No. 4 (175 to 430), more preferably No. 2 to No. 3 (220 to 295) in the blending consistency test. . The consistency indicates the external hardness of the grease. Here, as the consistency, the value of the penetration consistency measured according to JIS K 22207 is used.

[Drip point]
The grease composition of this embodiment is not related in terms of performance at the dropping point, but it is preferable that the thickener structure of the urea grease is 180 ° C. or higher as an indicator that the original bonding has been achieved. The dropping point refers to a temperature at which the viscous grease loses the thickener structure as the temperature increases. Here, the measurement of the dropping point can be carried out according to JIS K 22208.

[Shear stability when containing water]
In the grease composition of the present embodiment, in the blend consistency test after the roll stability test, the consistency after the test is preferably 395 or less, and the difference between before and after the test is within 90, More preferably, the penetration after test is 355 or less, and the difference between before and after the test is within 70. If the consistency after the test exceeds 395, the grease is likely to leak from the lubrication site such as a bearing, and the lubrication grease may not be supplied to the sliding portion. Further, if the difference between before and after the test exceeds 90, the thickener structure cannot be said to be stable against shearing in the first place, and the softening becomes intense and the outflow may be accelerated by long-time use. Here, the shear stability when containing water was carried out in accordance with the roll stability test method prescribed in ASTM D1831. Specifically, distilled water was blended in advance with the test grease at a ratio of 10% (distillation was 10% of water with respect to 90% of the grease) and dispersed uniformly. 50 g of this grease was weighed and subjected to a roll stability test, and sheared at 40 ° C. for 24 hours. Thereafter, the grease was taken out and the blending consistency was measured at 25 ° C. In addition, the blend penetration before and after the test is a value obtained by subtracting the blend penetration before the test from the blend penetration after the test.

[Water-resistant lubrication life test]
The grease composition of the present embodiment has a lubrication life in the water-resistant lubrication life test of preferably 180 minutes or more, more preferably 240 minutes or more, and further preferably 300 minutes or more. Here, the method of the water-resistant lubrication life test is as follows. FIG. 1 is a diagram showing an outline of a water-resistant lubrication life tester. As shown in the figure, this testing machine is a testing machine that evaluates the lubrication life of the bearing while injecting water into the housing. This method is an improvement of the water-washing water resistance tester specified in JIS K 2220 5.12. Specifically, unlike JIS, circulating water is not injected (300 ml / min) into the test ball bearing outer ring retainer (seal plate), but by injecting distilled water directly into the housing, it is clean and reliable. In addition, a more accurate amount of water can be injected, the test reliability is improved, and an accurate lubrication life can be measured. As a specific method, 5.0 g of the test grease is filled in the test bearing, and after the bearing is assembled in the housing, it is operated at 3,000 rpm while injecting distilled water heated to 40 ° C. into the 100 ml / min housing. To do. The injected water is discharged out through the test bearing. The service life of the grease was such that the bearing became high torque due to poor lubrication of the test grease, and when the current of the motor driving the bearing exceeded 200% during stable rotation, the control device was activated and the drive motor was stopped. The time was regarded as the life, and the weight of the bearing before and after the test was weighed and calculated as the amount of bearing wear.
(Test conditions)
Test bearing: No. 22208EAE4 (Spherical roller bearing)
Grease filling amount: 5.0 g
Rotation speed: 3,000rpm
Radial load: 15kgf
Water temperature: 40 ° C
Water volume: 100ml / min

≪Use of grease composition≫
The grease composition of the present embodiment can be used for machines, bearings, gears, etc. that are generally used, but also in severer environments in grease lubrication, for example, where moisture may be mixed. Excellent performance can be demonstrated. For example, in an automobile, a water pump, a cooling fan motor, a starter, an alternator, and various actuator parts around the engine, a propeller shaft, a constant velocity joint (CVJ), a power train such as a wheel bearing and a clutch, an electric power steering (EPS), It can be suitably used for lubricating various parts such as an electric power window, a braking device, a ball joint, a door hinge, a handle part, and a brake expander. In addition, construction machinery such as excavators, bulldozers, cranes, steel industry, paper industry, forestry machinery, agricultural machinery, chemical plants, power generation equipment, railway vehicles, etc. It is also preferable to use it. Other applications include seamless pipe screw joints and outboard motor bearings, which are also suitable for these applications.

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these examples.

≪Raw material≫
The raw materials used in Examples 1 to 7 and Comparative Examples 1 to 3 are as follows.

(Base oil)
Base oil A: paraffinic mineral oil obtained by refining dewaxing solvent belonging to Group 1 classified by the American Petroleum Institute (API) (kinematic viscosity at 100 ° C. is 11.25 mm ² / s, viscosity) A naphthenic mineral oil belonging to Group 5 (with a kinematic viscosity at 100 ° C. of 10.71 mm ² / s and a viscosity index of 30) was mixed at a ratio of 80 parts by mass to 20 parts by mass. Is.
(Thickener)
Urea A: A diurea thickener synthesized from 4,4'-diphenylmethane diisocyanate, octylamine and laurylamine.
Urea B: A diurea thickener synthesized from 4,4'-diphenylmethane diisocyanate, octylamine and oleylamine.
Urea C: Tetraurea thickener synthesized from 4,4'-diphenylmethane diisocyanate, stearylamine and hexamethylenediamine.
(Additive)
Additive A: calcium salicylate (INFINEUM, M7125) (BN 350 mg KOH / g)
Additive B: calcium salicylate (manufactured by INFINEUM, M7121) (BN225 mgKOH / g)
Additive C: Calcium finate (manufactured by LUBRIZOL, Lz6490) (BN145 mgKOH / g)
Additive D: calcium 12 hydroxystearate (manufactured by Sakai Chemical Industry Co., Ltd., SC-12H)
Additive E: Calcium stearate (manufactured by NOF Corporation, calcium stearate)
Additive F: calcium sulfonate (manufactured by KING, Na-sul 729) (BN 0.26 mg KOH / g)
Additive G: Calcium sulfonate (manufactured by LUBRIZOL, Lz5342) (BN307mgKOH / g)
Additive H: Zinc naphthenate (DAILUBEZ510 manufactured by DIC)
Additive I: Alkyl organic acid / alkyl organic acid ester and zinc / calcium complex salt (manufactured by KING, K-CORR G-1086A)
Additive J: sodium sulfonate (manufactured by LUBRIZOL, Lz5318A) (BN448 mgKOH / g)

≪Manufacturing method≫
According to the composition shown in Table 1, grease compositions according to Examples 1 to 7 and Comparative Examples 1 to 3 were obtained by a known method.

≪Test≫
About an Example and a comparative example, each test was done by the above-mentioned test method about a dropping point, a mixing consistency test, a roll stability test, and a water-resistant lubrication life test. Table 1 also shows the properties of the greases obtained in Examples and Comparative Examples. The consistency of the greases of Examples and Comparative Examples is No. 2 or No. 2.5 consistency. The dropping point is a value comparable to urea grease at 220 ° C. or higher for any grease. The index of water resistance can be determined from the results of a roll stability test and a water-resistant lubrication life test conducted on a sample in which 10% of water is mixed in the grease. It showed better lubricity than the comparative grease. Specifically, the greases according to all the examples had a long water-resistant lubrication life of more than 400 minutes, and in the water-resistant lubrication wear test, a bearing wear amount significantly lower than 20 mg could be realized. In addition, according to the verification test in the same system, “Example 6” containing an alkyl organic acid or an alkyl organic acid ester and containing both calcium sulfonate and zinc naphthenate has the most excellent water-lubrication wear resistance, Then, “Example 5” containing both calcium sulfonate and zinc naphthenate has excellent water-lubricating wear resistance, followed by “Example 1” and “implementation” containing either calcium sulfonate and zinc naphthenate. The result was that Example 4 ”had excellent water lubrication and wear resistance. On the other hand, the grease according to the comparative example was inferior in either or both of the water-resistant lubrication life and the water-resistant lubrication wear resistance.

Claims (9)

As a thickener, a urea compound,
Base oil,
As the first component of the additive, alkaline earth metal salicylate and / or alkaline earth metal phenate,
As a second component of the additive, metal soap that is a metal stearate,
A grease composition containing calcium sulfonate and / or zinc naphthenate as a third component of the additive.   The grease composition according to claim 1, comprising both calcium sulfonate and zinc naphthenate as the third component.   Furthermore, the grease composition of Claim 1 or 2 containing an alkyl organic acid and / or an alkyl organic acid ester.   The grease composition according to any one of claims 1 to 3, wherein the thickener is diurea or tetraurea.   The grease composition according to any one of claims 1 to 4, wherein a blending amount of the urea compound is 0.5 to 50 parts by mass with respect to 100 parts by mass of the entire grease composition.   The grease composition according to any one of claims 1 to 5, wherein a blending amount of the first component is 0.1 to 10 parts by mass with respect to 100 parts by mass of the entire grease composition.   The grease composition according to claim 1, wherein BN of the first component is 5 to 600 mg KOH / g.   The grease composition according to any one of claims 1 to 7, wherein a blending amount of the second component is 0.1 to 10 parts by mass with respect to 100 parts by mass of the entire grease composition.   The grease composition according to any one of claims 1 to 8, wherein a blending amount of the third component is 0.1 to 10 parts by mass with respect to 100 parts by mass of the entire grease composition.

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