KR20050085578A - Urea grease composition - Google Patents

Abstract

A urea grease composition containing from 2 to 30% by weight, based on the total weight of the lubricating base oil and the urea grease composition, wherein the thickener is selected from the following (1) to (3):

(1) a mixture of compound (a) and compound (b) containing 20 to 80 mol% of compound (a) with respect to the total amount of compound (a) and compound (b);

(2) a mixture formed by mixing the compound (c) and the mixture (1); or

(3) compound (c) alone,

Wherein the compound is represented by the formula:

(a) R ₁ NHCONHR ₂ NHCONHR ₁ ;

(b) R ₃ NHCONHR ₂ NHCONHR ₃ ; And

(c) R ₁ NHCONHR ₂ NHCONHR ₃

Wherein R ₂ is a diphenylmethane group, R ₁ is a C6-10 saturated alkyl group, R ₃ is a C14-40 saturated and / or unsaturated alkyl group, wherein the unsaturated alkyl group represents at least 20 mol% of the R ₃ alkyl group Make up).

Description

Urea Grease Composition {UREA GREASE COMPOSITION}

The present invention relates to a urea grease composition.

Urea greases are known as heat resistant greases because they generally have a higher dropping point and better thermal stability than general-purpose lithium-soap greases containing lithium-soap as a thickener.

Recently, urea greases have been found to have better wear resistance and lubricity than various metal soaps and inorganic materials as greases used as thickening agents.

It is believed that good wear resistance is because urea grease can form all forms of urea film and oxide film on lubricated sliding surfaces.

Urea grease is typically a linear type of bearings, ball joints, wheel bearings, alternators and cooling fans, mechanical ball screws and machine tools for vehicle constant velocity joints. Rapid growth is achieved with greases that apply to a wide variety of typical grease-lubricated sites, including guides, sliding surfaces of various construction equipment, and gear steel equipment, including bearings and various other industrial machinery.

The use of urea grease is in line with the current trends in micronization, weight reduction and anti-environmental use, including a wide range of CVJs (constant velocity joints), which have strong demands to reduce friction and wear on sliding surfaces. There is an ever-increasing number of special applications, such as automotive components and steel equipment requiring high heat resistant and wear resistant lubricating greases.

Although the characteristics of urea grease are developed year by year, the latest urea grease still has some improvements, depending on the intended application.

For example, household appliances and office automation equipment, in particular, need to have appropriate acoustic features, while it becomes essential to have low-noise features, abrasion resistance and low friction features that are indispensable for vehicle parts.

As a routine example of the noise generated by household appliances and office automation equipment, the use of vacuum cleaners, as these equipment advances, shrinks in size and increases suction power, as the bearings rotate at high speeds of 30,000 to 40,000 rpm, This results in high wind noise and tumbling noise, and the demand for noise reduction is severely increasing.

In addition, it is desirable to minimize the noise produced by the bearings of video cameras, video tape recorders and electronic equipment, acting as error signals and adversely affecting the electronic components.

Therefore, if grease capable of securing low noise and high lubrication can be applied to these bearings, it is very effective, so development of grease with improved characteristics is required.

Moreover, the softness of the vehicle is also improved year by year in the context of the acceleration of energy saving and economic fuel, so that the quality level required for the individual parts constituting the vehicle is increased year by year.

On the sliding surface of such a component, therefore, application of grease capable of securing low noise and high lubrication is highly desirable, and development of grease with improved characteristics is required.

Examples of lubricated parts of vehicles include cooling fan bearings in radiators, compressor and alternator bearings in air conditioning and heating units, constant velocity joints, overall joints in propulsion shafts, gears and bearings in steering units, ball screws and rack guides. Sliding bearings, and ball bearings of various kinds.

Low noise and low friction, smooth lubrication is directly related to energy saving, economical fuel and vehicle softness, and grease with excellent properties is very useful for this application. Therefore, more effective grease is required.

On the other hand, examples of lubricated parts in other industries where direct low noise requirements are limited compared to vehicles, household appliances and office automation equipment include many types of auto-assembled robots, ball screws and linear guides in machine tools, and a variety of construction equipment. Sliding zones, and bearings of various steel fixtures.

Although the direct low noise demand for grease is limited to these applications, the noise from the grease is not only the physical noise resulting from the agitation and the flow of grease, but also from the lubricated surface (noise and oil film caused by substances external to the boundary surface). Noise caused by metal-to-metal contact arising from breakage of the metal.

In fact, it can be said that substandard grease contaminated with inferior lubrication and external materials are likely to cause breakage and wear of the oil film and unacceptable noise at the interface. Therefore, its acoustic characteristics do not improve unless lubrication is enhanced. In other words, a grease with favorable acoustic properties means that its lubrication is also improved.

The low noise characteristics of grease can be further explained by the use of bearings, for example. In general, the lubrication mechanism of grease on a rolling-element bearing is such that the grease packed in the bearing temporarily vibrates and dissipates by rotation, after which a small amount of grease or oil is moved and channeled. It is supplied to the sliding zone while repeating, thereby lubricating the sliding zone. Here, the sound caused by the vibration occurring between the tumbling element of the bearing and the rolling surface appears as bearing noise.

Contamination of the grease with the precision work of the bearings and foreign substances and particles of the thickener in the grease are the factors that contribute to the bearing noise. Acoustic properties vary considerably depending on the type and type of condensing agent incorporated into the grease, as well as the dirt and dust entering the grease. In addition, these materials tend to impede smooth lubrication.

In general, in the case of urea grease, urea compounds obtained by the reaction of amines and isocyanates are used as thickeners and they are dispersed in oil and remain greased.

Urea greases are generally superior to soap greases in wear resistance because the urea compound (s) used herein as a thickener are likely to adsorb on the metal surface. However, many of the urea compounds obtained by the reaction between the above-mentioned amines and isocyanates are in a hard granular state, thereby undermining acoustic properties and adversely affecting smooth lubrication.

JP-A-1-139696, JP-A-2-77494 and JP-A-6-17080 are related to the acoustic characteristics of urea grease.

JP-A-1-139696 is interrupted by a thickener containing a mixture of diurea compounds (a) and (b) represented by the following formulas (a) and (b):

(a) R ₁ NHCONHR ₂ NHCONHR ₃

(b) R ₄ NHCONHR ₅ NHCONHR ₆

Wherein R ₂ is a diphenylmethane group, R ₁ and R ₃ each represent a C8 linear or branched saturated alkyl group, R ₅ represents a tolylene group or a tolylene group, and R ₄ and R ₆ each Alkyl-substituted aromatic groups or halogen-substituted aromatic groups).

JP-A-2-77494 denotes the above formulas (a) and (b) (wherein, R ₂ represents a totolylene group, and R ₁ and R ₃ each represent a C18 linear or branched saturated alkyl group or an unsaturated alkyl group). And R ₅ represents a diphenylmethane group and R ₄ and R ₆ represent a C8 linear or branched saturated alkyl group) containing a mixture of diurea compounds (a) and (b) Via a thickening agent.

JP-A-6-17080 represents the above formulas (a) and (b) (wherein R ₂ represents a tolylene group and R ₁ and R ₃ represent a C16-18 linear or branched saturated alkyl group or unsaturated alkyl group) , R ₅ represents a diphenylmethane group, R ₄ and R ₆ represent a C8 linear or branched saturated alkyl group), and a mixture of diurea compounds (a) and (b) It describes a thickening agent.

The following is another example of a literature on acoustic properties.

JP-A-3-28299 is an essential component containing a base oil containing an alkyldiphenyl ether oil and the above formula (a) (wherein R ₂ represents a C6-15 aromatic hydrocarbon group, R ₁ and R ₃ represents a C8-18 linear alkyl group and provides a concentration of a thickening agent which is a diurea compound represented by a ratio of C8 alkyl groups in the combination of R ₁ and R ₃ to 60 to 100 mol%). Describe the composition.

For page 8 of JP-A-2-80493, Table 2, for circulation conical roller bearings produced by mixing oxidized- and / or acid-modified polyolefins with 0.5 to 5% by weight with urea grease. The compositions are described and Table 2 further describes urea thickeners prepared from C8 octylamine, C18 stearylamine (octadecylamine) and MDI (diphenylmethane-4,4'-diisocyanate), and this action Explain that I create a beneficial effect on mechanical stability, wet shear stability, and the possibility of pressure transfer.

JP-A-3-243696 is a chemical formula (a) wherein R ₂ is a 3,3'-dimethyl-4,4'-biphenylene group, and R ₁ and R ₃ are C8-18 alkyl groups Diurea compounds represented by a mixture of oleyl groups). The technique described in this document has the drawback that the consistency yield is so low that one cannot obtain a grease with a consistency of about 250 without increasing the amount of thickener, and that the degree of oil separation is high at high temperature.

JP-A-58-185693 describes here diurea greases which are improved by incorporating one or more additives selected from alkenylsuccinic acid imides, metal salts of alkylbenzenesulfonic acids, or metal salts of petroleum sulfonic acid. The document further describes, as examples of these monoamines, the use of diisocyanates and monoamines for diurea grease, listed aliphatic amines such as stearylamine and oleylamine, and aromatic amines such as cyclohexylamine. The document indicates that the acoustic properties of the grease are favorable.

Another case is cited below where the production method has been examined to improve the acoustic properties of urea grease.

For example, JP-A-2-4895 describes a process for preparing urea grease that allows for improvement of acoustic properties, wherein when isocyanate and amine are added to the base oil and reacted with each other at a temperature of 60 to 120 ° C, A mixture of urea compounds was produced and the base oil was subjected to dispersion treatment using a kneading machine and further heated to 160-180 ° C. or less at a temperature-increasing rate of 0.5-2 ° C. per minute.

JP-A-3-190996 describes a process for producing greases which are said to have good acoustic properties, wherein isocyanate-dissolved or dispersed base oils and amine-dissolved or dispersed base oils are caused to react with each other. In order to mix them through a collision by pressurizing them in the reaction vessel, or to press them and put them in a rotary compressor, thereby causing each other to react.

In addition, JP-A-3-231993 describes a process for preparing low noise urea grease, which is formula (a) wherein R ₁ and R ₃ are C8-18 saturated alkyl groups, R ₂ is a tolylene group, A mixture consisting of 2 to 30% by weight of a urea compound represented by a diphenylmethane group or a dimethyldiphenylene group) and 98 to 70% by weight of a base oil, in order to completely dissolve the urea compound in the base oil. And a second step of heating to below < RTI ID = 0.0 >

As noted above, in many cases tolylene diisocyanate (TDI) or 3,3'-dimethyl-4,4'-biphenylenediisocyanate (TODI) is used as starting material to obtain urea grease compositions with good acoustic properties Has been.

Regarding their preparation method, the flocculation of the urea compound is prevented by dissolving two or more greases by using a kneading machine, performing a reaction in a high-pressure container, or heating and mixing them.

As urea grease production rises and the demand for low noise grease increases, there is a need for a clean working environment for grease production and better acoustic properties in the final product.

Many users require inexpensive high performance grease, use expensive TODI as a raw material, and require complicated production methods, urea grease will not be commercially competitive.

Moreover, from a health and safety perspective, the increase in grease production requires additional management, which deals with TDI as raw material and involves the installation of special equipment. As a result, it is necessary to consider the strengthening of the production equipment to improve the acoustic properties and the extended production process time.

The present invention has now found a specific urea grease composition with little oil separation at high temperatures and with a satisfactory consistency yield, with significant acoustic and lubrication properties. In addition, the urea grease composition can be produced in conventional grease-making facilities without requiring special equipment such as a high pressure cooker or kneading machine to disperse the thickener.

The urea grease composition of the present invention has good lubricating performance, can be easily spread, and is strongly adsorbed on the friction surface. In addition, the hindered concentrating action of the urea compound in the grease composition is an external substance and is not an obstacle here. Therefore, the urea grease composition of the present invention does not cause noise, and furthermore, its viscoelasticity can improve the strength of the oil film, and can synergize with the additive to form a more effective lubricating film on the sliding surface. Therefore, favorable grease lubrication can be obtained.

According to the present invention, a urea grease composition containing 2 to 30% by weight of a thickening agent relative to the total weight of the lubricating base oil and the urea grease composition, wherein the thickening agent is selected from the following (1) to (3): Composition:

(1) a mixture of compound (a) and compound (b) containing 20 to 80 mol% of compound (a) with respect to the total amount of compound (a) and compound (b);

(2) a mixture formed by mixing the compound (c) and the mixture (1); or

(3) compound (c) alone,

Wherein the compound is represented by the formula:

(a) R ₁ NHCONHR ₂ NHCONHR ₁ ;

(b) R ₃ NHCONHR ₂ NHCONHR ₃ ; And

(c) R ₁ NHCONHR ₂ NHCONHR ₃

(Wherein R ₂ is a diphenylmethane group, R ₁ is a C8 saturated alkyl group, R ₃ is a C14-20 saturated and / or unsaturated alkyl group, where the alkyl group is a component comprising at least 20 mol% of an oleyl component) ).

Preferably, the unsaturated alkyl group constitutes at least 25 mol%, more preferably at least 30 mol% of the R ₃ alkyl group.

In a preferred embodiment of the invention R ₁ is a saturated C8 alkyl group and / or R ₃ is a C14-20 saturated and / or unsaturated alkyl group, wherein the unsaturated alkyl group constituting at least 20 mol% of the R ₃ alkyl group is an oleyl group.

In a preferred embodiment of the present invention a urea grease composition containing from 2 to 30% by weight relative to the total weight of the lubricating base oil and the urea grease composition, wherein the thickener is selected from the following (1) to (3): Grease Composition:

(1) a mixture of compound (a) and compound (b) containing 20 to 80 mol% of compound (a) with respect to the total amount of compound (a) and compound (b);

(2) a mixture formed by mixing the compound (c) and the mixture (1); or

(3) compound (c) alone,

Wherein the compound is represented by the formula:

(a) R ₁ NHCONHR ₂ NHCONHR ₁ ;

(b) R ₃ NHCONHR ₂ NHCONHR ₃ ; And

(c) R ₁ NHCONHR ₂ NHCONHR ₃

Wherein R ₂ is a diphenylmethane group, R ₁ is a C6-10 saturated alkyl group, R ₃ is a C14-20 saturated and / or unsaturated alkyl group, wherein the unsaturated alkyl group is at least 20 mol% of the R ₃ alkyl group Make up).

In the present invention, urea having significant characteristics and performance when the thickener is incorporated into the lubricating base oil in an amount of 2 to 30% by weight, preferably 5 to 20% by weight, relative to the total weight of the urea grease composition as described above. Grease is obtained. When the content of the urea compound is less than 2% by weight as a thickener, the thickening effect is small and it is impossible to form grease. On the other hand, when the content of the urea compound exceeds 30% by weight as a thickener, the grease becomes too hard and a lubricating effect cannot be obtained.

When the proportion of the urea grease composition composed of the compound (a) in the mixture (1) is 20 mol% or less or more than 80 mol% with respect to the total amount of the compound (a) and the compound (b), the effect of using the mixture is almost No improvement in noise performance or oil separation.

The lubricating base oil used in the urea grease composition of the present invention may typically be one or more of vegetable oils, mineral oils, and / or synthetic oils.

Base oils of mineral origin may be those produced by mineral oils such as solvent purification or hydroprocessing.

Base oils of synthetic origin are typically hydrocarbon oils such as C ₁₀ -C ₅₀ hydrocarbon polymers, for example liquid polymers of alpha-olefins (poly (α-olefins)), ester type synthetic oils, silicone oils and / or ether types It may be a synthetic oil. They may be mixtures of these oils.

Examples of commonly used mineral oils include those sold by members of the Royal DutCh / Shell Group under the names "HVI", "MVIN", or "HMVIP".

Polyalphaolefins and base oils of the type produced by hydroisomerization of waxes, such as those sold by members of the Royal DutCh / Shell Group under the name "XHVI" (registered trademark), are also Can be used.

In a preferred embodiment, the urea grease composition of the present invention further comprises a zinc compound as an additive.

Specific examples of zinc compounds typically used in the urea grease compositions of the present invention are zinc diethyldithiocarbamate, zinc dipropyldithiocarbamate, zinc dibutyldithiocarbamate, zinc dipentyldithiocarbamate, zinc Dihexyldithiocarbamate, zinc didecyldithiocarbamate, zinc diisobutyldithiocarbamate, zinc di (2-ethylhexyl) dithiocarbamate, zinc diamyldithiocarbamate, zinc dilauryldithio Zinc dithiocarbamates such as carbamate, zinc distearyl-dithiocarbamate and zinc diphenyldithiocarbamate, and the like, and zinc ditolyldithiocarbamate, zinc disylyldithiocarbamate, zinc diethylphenyl Dithiocarbamate, zinc dipropylphenyldithiocarbamate, zinc dibutylphenyldithiocarbamate, zinc diphenylphenyldithiocarbamate, zinc dihexylphenyldi Ocarbamate, Zinc Dioctylphenyldithiocarbamate, Zinc Dinonylphenyldithiocarbamate, Zinc Didecylphenyldithiocarbamate, Zinc Didoceylphenyldithiocarbamate, Zinc Ditetradecylphenyldithiocarbamate and Zinc dihexadecylphenyldithiocarbamate. Similarly, specific examples of zinc dithiophosphate include zinc diethyldithiophosphate, zinc dipropyldithiophosphate, zinc dibutyldithiophosphate, zinc dipentyldithiophosphate, zinc dihexyldithiophosphate, zinc didecyldithiate. Ophosphate, zinc diisobutyldithiophosphate, zinc di (2-ethylhexyl) dithiophosphate, zinc diamyldithiophosphate, zinc dilauryldithiophosphate, zinc distearyldithiophosphate, zinc diphenyldithio Phosphate, zinc ditolyldithiophosphate, zinc disilyldithiophosphate, zinc diethylphenyldithiophosphate, zinc dipropylphenyldithiophosphate, zinc dibutylphenyldithiophosphate, zinc dipentylphenyldithiophosphate, zinc didiphosphate Hexylphenyldithiophosphate, zinc diheptylphenyldithiophosphate, zinc dioctylphenyldithi Phosphate, zinc dinonyl include phenyl dithio phosphate, didecyl phenyl zinc dithio phosphate, zinc didodecyl phenyl dithio phosphate, zinc di-tetradecyl phenyl phosphate and zinc dithio-di-phenyl-hexahydro dithio-phosphate. Metal elements such as S or P in these organometallic zinc compounds react with iron at the friction surface to form extreme pressure films such as iron phosphide or iron sulfide; The additive decomposes itself and inter-reacts with other additives to form a protective film.

Furthermore, the urea grease composition of the present invention surprisingly exhibits significant lubricating properties due to the synergistic effect of the S-P type additives with the urea thickener of the present invention, which has a significant penetration and adsorption at the interface.

The urea grease composition of the present invention may advantageously comprise a molybdenum compound as an additive.

Specific examples of molybdenum compounds typically used in the urea grease compositions of the present invention include molybdenum diethyldithiocarbamate, molybdenum dipropyldithiocarbamate, molybdenum dibutyldithiocarbamate, mol Ribdenium dipentyldithiocarbamate, molybdenum dihexyldithiocarbamate, molybdenum didecyldithiocarbamate, molybdenum diisobutyldithiocarbamate, molybdenum di (2-ethylhexyl) Molybdenum such as dithiocarbamate, molybdenum diamyldithiocarbamate, molybdenum dilauryldithiocarbamate, molybdenum distearyldithiocarbamate and molybdenum diphenyldithiocarbamate, and the like Denium dithiocarbamate, and molybdenum ditolyldithiocarbamate, molybdenum disylyldithiocarbamate, molybdenum diethylphenyldithiocarbamate, molybdenum di Propylphenyldithiocarbamate, molybdenum dibutylphenyldithiocarbamate, molybdenum diphenylphenyldithiocarbamate, molybdenum dihexylphenyldithiocarbamate, molybdenum dioctylphenyldithiocarbamate , Molybdenum dinonylphenyl-dithiocarbamate, molybdenum didecylphenyldithiocarbamate, molybdenum didodecylphenyldithiocarbamate, molybdenium ditetradecylphenyldithiocarbamate and molybdenum Dihexadecylphenyldithiocarbamate, and molybdenum dipentyldithiophosphate, molybdenum dipropyl dithiophosphate, molybdenum dibutyldithiophosphate, molybdenum dipentyldithiophosphate, molybdenum dithiophosphate Hexyldithiophosphate, molybdenum didecyldithiophosphate, molybdenum diisobutyldithiophosphate, molybdenum di (2-ethylhexyl) dithiophosphate Yate, molybdenum diamyldithiophosphate, molybdenum dilauryldithiophosphate, molybdenum distearyldithiophosphate, molybdenum diphenyldithiophosphate, molybdenum ditolyldithiophosphate, molybdenum Denium disylyldithiophosphate, molybdenum diethylphenyldithiophosphate, molybdenum dipropylphenyldithiophosphate, molybdenum dibutylphenyldithiophosphate, molybdenum dipentylphenyldithiophosphate, molybdenum Dihexylphenyldithiophosphate, molybdenum diheptylphenyldithiophosphate, molybdenum dioctylphenyldithiophosphate, molybdenum dinonylphenyldithiophosphate, molybdenium didecylphenyldithiophosphate, molybdenum Didodecylphenyldithiophosphate, molybdenum ditetradecylphenyldithiophosphate and molybdenum dihexaphenyl Molybdenum dithiophosphate, such as dithiophosphate, and molybdenum compounds described in JP 5-66435 Bl, that is, molybdenum complexes, diethanolamine and molybdenum sources that are reaction products of fatty oils. .

These above-mentioned molybdenum compounds are easily and clearly adsorbed to the metal surface constituting the sliding surface, decomposed by the heat generated on the friction surface to produce Mo0 ₃ and MoS ₂ , and this MoS ₂ component is incorporated into the metal. Diffuses and has a mechanism of action to protect the friction surface.

In addition, surprisingly, the urea grease compositions of the present invention exhibit significant lubricating properties due to the synergistic effects of these molybdenum compounds and the physical and chemical properties such as adsorption and penetration of the urea thickeners of the present invention.

To further improve performance, additives such as antioxidants, preservatives and extreme pressure agents can typically be added to the urea grease of the present invention.

Antioxidants including, for example, alkylphenols, minor free phenols, alkylamines, diphenylamines and triazines; Anticorrosion agents include calcium sulfonate, sodium sulfonate, barium sulfonate and amino derivatives or metal salts of carboxylic acids; Extreme pressure agents including sulfurized oils or fats, sulfurized olefins, phosphate esters, tricresyl phosphate, trialkyl thiophosphates and triphenyl phosphate thionates can be used conventionally.

Lubricants for bearings may advantageously comprise the urea grease composition of the present invention.

Accordingly, the present invention further provides a method for lubricating a bearing comprising packing the bearing with the urea grease composition of the present invention.

In addition, lubricants for application to the sliding surface of the machine in relative motion may advantageously comprise the urea grease composition of the present invention.

Accordingly, the present invention further provides a method for lubricating the sliding surface of a machine in relative motion, comprising lubricating the sliding surface with the urea grease composition of the present invention.

The present invention furthermore provides the use of the urea grease composition of the invention as a noise-reducing grease composition and in particular the use of said grease composition for reducing noise in bearing applications.

The invention is described below with reference to the following examples, which do not in any way limit the scope of the invention.

Example 1-5

MDI (diphenylmethane-4,4'-diisocyanate) and 60 parts by weight of the base oil at a synthesis ratio indicated in Table 1 were placed in a grease pot and heated to approximately 50 ° C; After dissolving the MDI, octylamine dispersed in 20 parts by weight of the base oil was added slowly with vigorous stirring. After approximately 10 minutes, oleylamine dispersed in 20 parts by weight of the base oil was added and stirring continued.

The reaction of the diisocyanate with the amine increased the temperature of the contents of the grease pot, and the reaction was completed by heating to 168 ° C. and holding at this temperature for approximately 30 minutes, then cooling to room temperature, after which to obtain grease Processing was done in a triple roll mill.

Examples 6 and 7

Mixture of octylamine and oleylamine dissolved in 40 parts by weight of MDI and 60 parts by weight of base oil in a grease pot, heated to approximately 50 ° C., and dissolved MDI at the synthesis ratios indicated in Table 1. Is slowly added to the solution and the mixture is vigorously stirred. To finish the reaction, the contents of the grease pan were heated to 168 ° C., held at this temperature for approximately 30 minutes, then cooled to room temperature, with a triple roll mill to obtain grease. Processed.

Example 8-10

In Table 2 the synthesis ratios are shown. 50 parts by weight of the grease of Example 1 and 50 parts by weight of the grease of Example 6 are mixed evenly with a spatula to provide the grease of Example 8.

50 parts by weight of the grease of Example 2 and 50 parts by weight of the grease of Example 6 are mixed evenly with a spatula to provide the grease of Example 9.

50 parts by weight of the grease of Example 3 and 50 parts by weight of the grease of Example 6 are mixed evenly with a spatula to provide the grease of Example 10.

Example 11-16

MDI (diphenylmethane-4,4'-diisocyanate) and 60 parts by weight of base oil in a grease pot at the synthesis ratios indicated in Tables 3 and 4 were heated to approximately 50 ° C., and the MDI was dissolved, Octylamine dissolved in 20 parts by weight is slowly added with vigorous stirring. After approximately 10 minutes, octylamine and other amines mixed in the composition shown in Table 3 were added together with 20 parts by weight of the base oil and stirring continued.

The temperature of the contents of the grease pot was increased by the reaction of the diisocyanate with the amine, and the reaction was completed by heating to 168 ° C. and holding at this temperature for approximately 30 minutes, then cooling to 80 ° C., listed in Table 3 Additives were then added and treated with a triple-roll mill to obtain grease.

Comparative Example 1-15

The diisocyanate and 60 parts by weight of the base oil are placed in a grease pan at the synthesis ratios indicated in Table 5-7, and the diisocyanate is dissolved at the following temperature, followed by the slow addition of the amine dispersed in 40 parts by weight of the base oil with strong stirring. do.

The contents of the grease pot were heated to 168 ° C., held at this temperature for approximately 30 minutes to complete the reaction, then cooled to room temperature and treated with a triple-roll mill to obtain grease.

The additives shown in Table 7 in Comparative Examples 13-15 were added after cooling to room temperature and then treated with a triple-roll mill to provide grease.

In Table 1 and Table 3-7,

MDI is diphenylmethane-4,4'-diisocyanate; Heating temperature about 50 ℃

TDI is 2,4 / 2,6 (80% / 20%) trilene-4,4'-diisocyanate; Heating temperature

TODI is 3,3'-vitylene-4,4'-diisocyanate; Heating temperature about 75 ° C.

The viscosity at 100 ° C. of the oils presented in the examples and comparative examples is 10.12 mm ² / sec for mineral oil, 12.69 mm ² / sec for alkyl diphenyl ether oil, and 12.70 mm ^{2 for} poly (α-olefin) oil. / Second.

In the thickener (mol%) column of Tables 1 and 2,

(a) represents compound R ₁ NHCONHR ₂ NHCONHR ₁ ;

(b) represents compound R ₃ NHCONHR ₂ NHCONHR ₃ ;

(C) represents compound R ₁ NHCONHR ₂ NHCONHR ₃ ,

Wherein R ₂ is a diphenylmethane group, R ₁ is a C8 saturated alkyl group, and R ₃ is a C18 unsaturated alkyl group;

(1) represents a diurea compound in Example 1,

(2) represents a diurea compound in Example 2,

(3) represents a diurea compound in Example 3,

(6) shows a diurea compound in Example 6.

Additives in Tables 3, 4 and 7:

Additive A is primary Zn-DTP (primary zinc dithiophosphate) with C4 and C5 alkyl groups,

Additive B is secondary Zn-DTP (secondary zinc dithiophosphate) with C3 and C6 alkyl groups,

Additive C is Zn-DTC (zinc dithiocarbamate) with C5 alkyl group,

Additive D is mainly Mo-DTC (molybdenum dithiocarbamate) with a C8 alkyl group,

Additive E is a molybdenum complex compound as described in JP 5-66435 Bl,

Additive F is Mo-DTP (molybdenum dithiophosphate) with prominent C8 alkyl groups,

Additive G is a 2,4-bis (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylamine) -1,3,5-triazine and octyldiphenylamine mineral oil Slurry formed by mixing at a ratio of 1: 2 at a concentration of 50%.

Example One 2 3 4 5 6 7 MDI (g) 10.84 9.88 8.91 10.84 9.88 9.50 9.50 Octylamine (g) 9.15 6.10 3.05 9.15 6.10 4.91 4.91 Oleylamine (g) 4.01 8.02 12.04 4.01 8.02 9.59 9.59 Mineral oil (g) 176 176 176 - - 176 - Alkyl diphenyl ether (g) - - - 176 176 - - Poly (α-olefin) (g) - - - - - - 176 Thickener (%) 12 12 12 12 12 12 12 Thickener (mol%) (a) / (b) = 75/25 (a) / (b) = 50/50 (a) / (b) = 25/75 (a) / (b) = 75/25 (a) / (b) = 50/50 (c) = 100 (c) = 100 Consistency (dmm) 245 241 241 232 245 225 247 Dropping point (℃) > 250 > 250 > 250 > 250 > 250 > 250 > 250 Oil separation (mass%) 0.6 1.1 2.4 0.4 0.8 0.4 0.7 Noise test after 120 seconds 5 12 12 10 8 7 7

Example 8 9 10 Thickener (mol%) (1) + (6) (a) / (b) / (c) = 37.5 / 12.5 / 50 (2) + (6) (a) / (b) / (c) = 25/25/50 (3) + (6) (a) / (b) / (c) = 12.5 / 37.5 / 50 Thickener Content (%) 12 12 12 Consistency (dmm) 232 235 233 Dropping point (℃) > 250 > 250 > 250 Oil separation (mass%) 0.5 0.4 0.4 Noise test after 120 seconds 5 7 7

Example 11 12 13 14 MDI (g) 10.62 10.59 10.59 9.79 Octylamine (g) 8.52 8.52 8.52 6.04 Tetradecylamine (g) 0.15 0.12 0.12 0.20 Hexadecylamine (g) 0.36 0.33 0.33 1.67 C16 amine (double bond one C16 amine) (g) 0.25 0.19 0.19 - Stearylamine (g) 0.50 1.72 1.72 3.75 Oleylamine (g) 3.60 2.52 2.52 2.52 C20 amine (g) - 0.02 0.02 0.03 Mineral oil (g) 126 176 50 50 Alkyl diphenyl ether (g) - - - 76 Poly (α-olefin) (g) 50 - 126 50 Thickener Content (%) 12 12 12 12 Thickener (mol%) (a) / (b) = 70/30 (a) / (b) = 70/30 (a) / (b) = 70/30 (a) / (b) = 50/50 R ₃ unsaturated component (mol%) 78 55 55 30 Additive A (g) 2.0 2.0 - 2.0        B (g) - - 2.0 -        C (g) - - - -        D (g) - - 2.0 4.0        E (g) 4.0 2.0 - -        F (g) - 2.0 2.0 -        G (g) 2.0 2.0 2.0 2.0 Consistency (dmm) 255 243 253 248 Dropping point (℃) > 250 > 250 > 250 > 250 Oil separation (mass%) 1.8 1.3 1.1 0.9 Noise test after 120 seconds 7 5 10 8 ASTMD2246 Shell 4 Ball Impact Resistance Test (120rpm, 40㎏, 75 ℃, 1h) mm 0.55 0.54 0.49 0.51 ASTMD3336 Bearing Service Life Test (150 ° C, 6204, Deep Groove Ball Bearing) > 1000 > 1000 - > 1000 Bowden friction test (room temperature, sliding speed 10㎜ / sec, surface pressure 1000Mpa) Friction coefficient μ 0.128 0.130 0.127 0.129

Example 15 16 MDI (g) 9.00 9.43 Octylamine (g) 3.65 4.85 Tetradecylamine (g) 0.28 0.32 Hexadecylamine (g) 2.32 2.73 C16 amine (double bond one C16 amine) (g) - - Stearylamine (g) 5.20 2.13 Oleylamine (g) 3.50 4.54 C20 amine (g) 0.05 - Mineral oil (g) 176 176 Poly (α-olefin) (g) - - Thickener Content (%) 12 12 Thickener (mol%) (a) / (b) = 30/70 (c) = 100 R ₃ unsaturated component (mol%) 30 45 Additive A (g) - 1.0        B (g) - -        C (g) 2.0 1.0        D (g) - -        E (g) 4.0 3.0        F (g) - 1.0        G (g) 2.0 2.0 Consistency (dmm) 240 235 Dropping point (℃) > 250 > 250 Oil separation (mass%) 2.2 1.5 Noise test after 120 seconds 4 8 ASTMD2246 Shell 4 Ball Impact Resistance Test (120rpm, 40㎏, 75 ℃, 1h) mm 0.52 0.48 ASTMD3336 bearing service life test (150 ° C, 6204, deep groove ball bearing) h - > 1000 Bowden friction test (room temperature, sliding speed 10㎜ / sec, surface pressure 1000Mpa) Friction coefficient μ 0.126 0.129

Comparative example One 2 3 4 5 6 MDI (g) 11.80 7.95 12.93 11.88 - - TODI (g) - - - - 12.13 12.27 TDI (g) - - - - - - Octylamine (g) 12.20 - - - 11.87 - Oleylamine (g) - 16.05 - - - 11.73 p -toluidine (g) - - 11.07 - - - p -chloroaniline (g) - - - 12.12 - - Mineral oil (g) 176 176 176 176 176 176 Thickener Content (%) 12 12 12 12 12 12 Consistency (dmm) 279 258 326 400 325 372 Dropping point (℃) > 250 185 > 250 > 250 > 250 > 250 Oil separation (mass%) 1.2 3.9 2.2 7.6 6.6 3.1 Noise test after 120 seconds 52 56 2,229 > 10,000 151 191

Comparative example 7 8 9 10 11 12 MDI (g) - - - - - - TODI (g) 13.25 12.21 - - - - TDI (g) - - 9.66 6.15 10.76 9.74 Octylamine (g) - - 14.34 - - - Oleylamine (g) - - - 17.85 - - p -toluidine (g) 10.75 - - - 13.24 - p -chloroaniline (g) - 11.79 - - - 14.26 Mineral oil (g) 176 176 176 176 176 176 Thickener Content (%) 12 12 12 12 12 12 Consistency (dmm) 400 408 408 372 369 406 Dropping point (℃) > 250 > 250 182 151 > 250 > 250 Oil separation (mass%) 4.6 3.5 20.5 80.5 3.4 5.3 Noise test after 120 seconds 461 > 10,000 678 424 581 > 10,000

Comparative example 13 14 15 MDI (g) - - 11.88 TODI (g) 12.21 - - TDI (g) - 9.74 - p -chloroaniline (g) 11.79 14.26 12.12 Mineral oil (g) 176 176 50 Poly (α-olefin) (g) - - 126 Thickener Content (%) 12 12 12 Additive A (g) 1.0 1.0 -        B (g) - - 1.0        C (g) 1.0 1.0 1.0        D (g) - - 3.0        E (g) 3.0 3.0 1.0        F (g) 1.0 1.0 -        G (g) 2.0 2.0 2.0 Consistency (dmm) 410 405 415 Dropping point (℃) > 250 > 250 > 250 Oil separation (mass%) 3.6 5.8 10.1 Noise test after 120 seconds > 10,000 > 10,000 > 10,000 ASTMD2246 Shell 4 Ball Impact Resistance Test (120rpm, 40㎏, 75 ℃, 1h) mm - - - ASTMD3336 bearing service life test (150 ° C, 6204, deep groove ball bearing) h 680 380 520 Bowden friction test (room temperature, sliding speed 10㎜ / sec, surface pressure 1000Mpa) Friction coefficient μ

In the table, the properties of the examples and the comparative examples were tested using the following methods.

Consistency: JIS K2220

Dropping point: JIS K2220

Oil Separation: JIS K2220 method was performed under conditions of 150 ° C. temperature for 24 hours.

Noise test: Bearing noise was measured in each grease using an NSK Noise Tester (commercially available from NSK Ltd) as described in JP 53 2357 B1.

Bowden friction test: The coefficient of friction is used to evaluate the friction at the friction surface between the reciprocating layer and the pins subjected to the normal friction load on the plate fitted with the layer, with a mechanism to apply the vertical load to the layer. It measured with the apparatus mentioned above.

1. Form: Interoperable Sliding Friction Tester

2. Test piece: fixed slide: steel sphere or rod

Transfer slide: steel plate 3 x 40 x 100 mm or so

3. Sliding speed: 0.05-20 mm / s

4. Sliding distance: 20-50 mm

5. Load: 0.1 kg to 10 kg

6. Temperature: room temperature to 200 ℃

7. Drive method: injection screw slide, lead 2 mm

8. Drive motor: AC servo motor 400 W

The results of this experiment are described below.

(1) Urea grease composition according to the invention with excellent noise and lubricity, using conventional equipment for producing grease without requiring special equipment such as kneading machines or autoclaves to bring about dispersion of the thickener. It is possible to generate.

(2) The urea grease composition of the present invention provides excellent consistent yields with a small amount of thickening agent that hardens the grease; And

(3) The urea grease of the present invention has a high dropping point and shows no oil separation at high temperatures.

Claims (10)

A urea grease composition containing from 2 to 30% by weight, based on the total weight of the lubricating base oil and the urea grease composition, wherein the thickener is selected from the following (1) to (3): (1) a mixture of compound (a) and compound (b) containing 20 to 80 mol% of compound (a) with respect to the total amount of compound (a) and compound (b); (2) a mixture formed by mixing the compound (c) and the mixture (1); or (3) compound (c) alone, Wherein the compound is represented by the formula: (a) R ₁ NHCONHR ₂ NHCONHR ₁ ; (b) R ₃ NHCONHR ₂ NHCONHR ₃ ; And (c) R ₁ NHCONHR ₂ NHCONHR ₃ Wherein R ₂ is a diphenylmethane group, R ₁ is a C6-10 saturated alkyl group, R ₃ is a C14-40 saturated and / or unsaturated alkyl group, wherein the unsaturated alkyl group represents at least 20 mol% of the R ₃ alkyl group Make up). The urea grease composition of claim 1, wherein the unsaturated alkyl group comprises at least 30 mol% of the R ₃ alkyl group. The urea grease composition according to claim 1 or 2, wherein the oleyl component constitutes 20 mol% or more of the R ₃ alkyl group. The urea grease composition according to any one of claims 1 to 3, wherein the composition further contains a zinc compound as an additive. 5. The urea grease composition of claim 4, wherein said zinc compound is selected from zinc dithiocarbamate and zinc dithiophosphate. The urea grease composition according to any one of claims 1 to 5, wherein the composition further contains a molybdenum compound as an additive. 7. The urea of Claim 6 wherein said molybdenum compound is selected from molybdenum dithiocarbamate, molybdenum dithiophosphate and molybdenum complexes which are reaction products of fatty oils, diethanolamines and molybdenum sources. Grease composition. 8. The urea grease composition according to claim 1, wherein the thickener is present in an amount of from 5 to 20% by weight, relative to the total weight of the urea grease composition. A method for lubricating a bearing comprising packing the bearing with the urea grease composition according to any one of claims 1 to 8. A method of lubricating a sliding surface of a machine in relative motion, comprising lubricating the sliding surface with the urea grease composition according to any one of claims 1 to 8.