CN1723268B - Urea grease composition - Google Patents

Abstract

A urea grease composition comprising a lubricating base oil and a thickener of 2-30% by weight relative to the total weight of the urea grease composition, wherein the thickener is selected from the group consisting of: (1) comprising compound (a) and A mixture of compound (b), which contains 20-80mol% of compound (a) relative to the total amount of compound (a) and compound (b); (2) obtained by mixing compound (c) and mixture (1) or (3) separate compound (c), wherein each compound is represented by general formula (a) R ₁ NHCONHR ₂ NHCONHR ₁ , (b) R ₃ NHCONHR ₂ NHCONHR ₃ and (c) R ₁ NHCONHR ₂ NHCONHR ₃ Represents, wherein R ₂ is a diphenylmethane group, R ₁ is a C6-10 saturated alkyl group and R ₃ is a C14-40 saturated and/or unsaturated alkyl group, wherein the unsaturated alkyl group accounts for at least 20 mol of the R ₃ alkyl group %.

Description

Urea grease composition

This invention relates to urea grease compositions.

Urea grease is known as a heat resistant grease because it has a higher dropping point and better thermal stability than common lithium soap greases that contain lithium soap as a thickener.

In recent years, it has been found that urea grease has better wear resistance and lubricity than grease with various metal soaps and inorganic materials as thickeners.

It is believed that the excellent wear resistance of urea grease is due to its ability to form both urea and oxide films on lubricated sliding surfaces.

Urea greases have grown rapidly due to the ease with which the grease can be applied to typical grease lubricated areas, including bearings, ball joints, wheel bearings, alternators and cooling fans of various vehicle constant velocity couplings , ball screws and linear guides of machine tools, various sliding areas of construction equipment, bearings and gears of steel equipment and various other industrial machinery and equipment.

The usage of urea grease is steadily rising in specific applications such as various vehicle components including CVJs (Constant Velocity Joints), in response to the current trend towards miniaturization, weight reduction and environmental The trend in demand in steel equipment for frictional greases strongly demands durability and reduced frictional losses in the sliding zone.

Although the properties of urea greases are evolving every year, the latest urea greases leave room for improvement depending on the desired application.

For example, home appliance equipment and office automation equipment are particularly required to have appropriate sound characteristics, while vehicle parts are required to have essential low-noise performance, anti-wear performance and low-friction performance.

Taking vacuum cleaners as a familiar example of noise generated by household electrical equipment and office automation equipment, noise reduction is becoming increasingly critical as the size of the equipment decreases and suction forces increase in such equipment, where bearings in the 30,000- Rotating at a high speed of 40,000rmp, resulting in high aerodynamic noise and rolling noise.

In addition, it is desirable to minimize the noise generated by the bearings of video cameras, video tape recorders and electronic equipment, since these noises can act as false signals and adversely affect electronic components.

Therefore, it would be very effective if a grease capable of ensuring low noise and high lubricity is applied to the above-mentioned bearings, and thus the development of grease with improved properties is desired.

Also, under conditions where progress in energy saving and fuel saving is further accelerated, the slipperiness of vehicles is also improving day by day, so that the required quality level of individual components constituting the vehicle is also increasing day by day.

Therefore, it is highly desirable to apply a grease capable of ensuring low noise and high lubricity to the sliding areas of these parts, and thus the development of a grease with improved properties has been demanded.

Examples of vehicle components that require lubrication include various types of bearings such as cooling fan bearings for radiators, compressor bearings and alternator bearings for air conditioners, constant velocity couplings, universal joints for power cardan shafts, Gears and bearings of steering gears, ball screws, sliding areas and ball joints of rack guides.

Smooth lubrication with low noise and low friction is directly related to energy saving, fuel saving and vehicle smoothness, and greases exhibiting excellent properties in these applications are very useful. Therefore, there is a need for more efficient greases.

On the other hand, examples of parts requiring lubrication in other industrial fields include bearings of various automatic assembly robots, ball screws and linear guides of machine tools, various sliding areas of construction equipment, and various bearings of steel equipment, which There is a limit in immediate requirements for low noise compared to vehicles, home electric equipment, and office automation equipment.

Noise from grease is not only physical noise caused by agitation and flow of grease, but also noise generated at the interface between lubricated surfaces, although the immediate requirement for low noise in grease has limitations in such applications (Noise caused by foreign substances on the interface and metal-to-metal contact caused by oil film damage).

Of course, it can be considered that substandard greases that are poor in lubrication and contaminated with foreign substances tend to cause oil film breakage and wear at the interface as well as unacceptable noise generation. Therefore, its noise reduction characteristics will not be improved unless lubricity is improved. That said, a grease with good noise-reducing properties means that its lubricity is also improved.

Bearings are used as an example to further explain the low-noise properties of grease. In general, the lubrication mechanism of grease on rolling element bearings is that the grease filled in the bearing temporarily oscillates and disperses due to rotation, and thereafter, with the repetition of agitation and channeling, traces of grease or Oil is fed into the sliding area, thereby lubricating the sliding area. Among them, the sound generated by the vibration between the rolling elements of the bearing and the rolling surface is manifested as bearing noise.

The working accuracy of the bearing, the pollution of the grease by foreign substances and the particles of the thickener in the grease are all factors that cause noise. The sound characteristics vary significantly with the form and type of dirt and dust not only penetrating the grease but also with the form and type of thickener introduced. In addition, these substances often become obstacles to smooth lubrication.

In general, for urea greases, urea compounds obtained by reacting amines and isocyanates can be used as thickeners and they are dispersed in oil and maintain a grease state.

Urea greases are generally superior to soap greases in terms of wear resistance because the urea compound used as a thickener tends to adsorb to metal surfaces. However, many of the aforementioned urea compounds obtained by reacting amines and isocyanates are hard and granular, thus impairing noise-reducing properties and adversely affecting smooth lubrication.

JP-A-1-139696, JP-A-2-77494 and JP-A-6-17080 relate to the acoustic properties of urea greases.

JP-A-1-139696 discloses a thickener comprising a mixture of diurea compounds (a) and (b) respectively represented by the following general formulas (a) and (b):

(a) R ₁ NHCONHR ₂ NHCONHR ₃

(b) R ₄ NHCONHR ₅ NHCONHR ₆

wherein _R2 is a diphenylmethane group, each of _R1 and _R3 represents a C8 linear or branched saturated alkyl group, _R5 represents a tolylene or bis-tolylylene group, and each of _R4 and _R6 represents an alkyl group A substituted aromatic group or a halogen substituted aromatic group.

JP-A-2-77494 discloses a thickener comprising a mixture of diurea compounds (a) and (b) represented by the aforementioned general formulas (a) and (b), however, wherein _R represents bis-toluene R ₁ and R ₃ each represent a C18 linear or branched saturated or unsaturated alkyl group, R ₅ represents a diphenylmethane group, and R ₄ and R ₆ represent a C8 linear or branched saturated alkyl group.

JP-A-6-17080 discloses a thickener comprising a mixture of diurea compounds (a) and (b) represented by the aforementioned general formulas (a) and (b), however, wherein _R represents tolylene , R ₁ and R ₃ each represent a C16-18 straight-chain or branched saturated or unsaturated alkyl group, R ₅ represents a diphenylmethane group, and R ₄ and R ₆ represent a C8 straight-chain or branched saturated alkyl group .

The following are other examples of literature on acoustic properties.

JP-A-3-28299 discloses a grease composition in which a base oil comprising an alkyl diphenyl ether oil as an essential component is mixed with a thickener of a diurea compound represented by the aforementioned general formula (a), However, where _R2 represents a C6-15 aromatic hydrocarbon group, _R1 and _R3 represent a C8-18 straight-chain alkyl group, provided that the proportion of C8 alkyl group in the combination of _R1 and _R3 is 60-100mol% .

Table 2 on page 8 of JP-A-2-80493 discloses a composition for tapered roller bearings by mixing urea grease with 0.5-5 wt% oxidation-modified polyolefin and/or acid modified polyolefins, and further disclosed in Table 2 that the urea thickener is derived from C8 octylamine, C18 stearylamine (octadecylamine) and MDI (diphenylmethane-4,4' - diisocyanates) and demonstrated that these reagents have a favorable effect on mechanical stability, wet shear stability and pressure transfer capability.

JP-A-3-243696 discloses a diurea compound represented by the aforementioned general formula (a), wherein R ₂ is 3,3'-dimethyl-4,4'-diphenylene, R ₁ and R ₃ is a mixed group of C8-18 alkyl and oleyl. The disadvantages of the technique disclosed in this document are that the yield is too low to obtain a grease having a consistency of about 250 without increasing the amount of thickener and the degree of oil separation at high temperature is too great.

JP-A-58-185693 discloses a kind of diurea lubricating grease, it is selected from alkenyl succinic acid imide, alkylbenzene sulfonic acid metal salt or petroleum sulfonic acid metal salt by introducing one or more additives to improve performance. This document further discloses the preparation of diurea greases using diisocyanates and monoamines, and cites aliphatic amines, such as stearylamine and oleylamine, and aromatic amines, such as cyclohexylamine, as examples of the aforementioned monoamines. The document also states that the grease has satisfactory sound properties.

Other proposals examining production methods to improve sound characteristics are cited below.

For example, JP-A-2-4895 discloses a production method of urea grease capable of improving the sound characteristics of urea grease in which isocyanate and amine are added to base oil and allowed to react with each other at a temperature of 60-120°C , and then use a kneader to disperse the mixture of the obtained urea compound and base oil, and then heat it to 160-180° C. at a heating rate of 0.5-2° C./min.

JP-A-3-190996 discloses a method for preparing a grease said to have good sound characteristics, wherein a base oil in which isocyanate is dissolved or dispersed and a base oil in which amine is dissolved or dispersed are passed through a reactor under pressure They are mixed by impingement to cause them to react with each other, or they are pressurized and introduced under a rotating impeller so as to cause them to react with each other.

In addition, JP-A-3-231993 discloses a method for producing low-noise urea grease, the method comprising heating 2 to 30% by weight of the urea compound represented by the aforementioned general formula (a), wherein R _{and R} are C8 -18 saturated alkyl, R ₂ is tolylene, diphenylmethane or dimethyl diphenylene, and a mixture of 98-70wt% base oil to 170-230 ° C to completely dissolve the urea compound in A first step in the base oil, and a second step of cooling the solution obtained in the first step at a rate of at least 5 °C/sec.

As described in the above documents, in many cases toluene diisocyanate (TDI) or 3,3'-dimethyl-4,4'-diphenylene diisocyanate (TODI) is used as Starting material for urea grease compositions.

As for their preparation methods, agglomeration of urea compounds can be avoided by using a kneader, allowing the reaction to proceed in an autoclave, or heating and then mixing two or more types of greases to dissolve them.

As urea grease production rises and the demand for low-noise greases grows, there is also a need for a cleaner working environment for grease production and better sound characteristics of the final product.

Many users need a grease with low price and high performance, and urea grease that uses expensive TODI as a raw material and requires a complicated production process will not be commercially competitive.

Further from a health and safety standpoint, the increase in grease production requires more attention to be paid to the handling of TDI as a raw material and the installation of special equipment. As a result, it is required to consider increasing production facilities for improving sound characteristics and prolonging production process time.

The present inventors have discovered specific urea grease compositions which have a satisfactory yield, low oil separation at elevated temperatures and excellent sound and lubricity properties. Furthermore, the urea grease compositions can be produced in conventional grease manufacturing facilities without the need for specialized equipment such as autoclaves or kneaders to disperse the thickener.

The urea grease composition according to the present invention has good lubricating ability and can spread easily on friction surfaces and strongly adsorb to friction surfaces. Furthermore, the interfered thickening function of the urea compound in the grease composition is not hindered therein like foreign substances. Therefore, the urea grease composition of the present invention does not cause noise under the synergistic effect of additives, and additionally enhances oil film strength due to its viscoelasticity and can form a more effective lubricating film on sliding surfaces. Therefore, ideal grease lubrication can be obtained.

According to the present invention there is provided a urea grease composition, which comprises a lubricating base oil and a thickener of 2-30 wt% relative to the total weight of the urea grease composition, wherein the thickener is selected from:

(1) a mixture comprising compound (a) and compound (b), the mixture containing 20-80 mol% of compound (a) relative to the total amount of compound (a) and compound (b);

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

(3) compound (c) alone,

wherein the respective compounds are represented by the following general formula:

(a) R ₁ NHCONHR ₂ NHCONHR ₁ ,

(b) R ₃ NHCONHR ₂ NHCONHR ₃ and

(c) R ₁ NHCONHR ₂ NHCONHR ₃ means,

Wherein _R2 is a diphenylmethane group, _R1 is a C6-10 saturated alkyl group and _R3 is a C14-20 saturated and/or unsaturated alkyl group, wherein the unsaturated alkyl group accounts for at least 20 mol% of the _R3 alkyl group.

Preferably, unsaturated alkyl groups represent at least 25 mol %, more preferably at least 30 mol % of the _R3 alkyl groups.

In a preferred embodiment according to the present invention, R ₁ is C8 alkyl and/or R ₃ is C14-20 saturated and/or unsaturated alkyl, wherein at least 20 mol% of R ₃ alkyl is unsaturated alkyl It is oil based.

In a preferred embodiment according to the present invention, the urea grease composition comprises lubricating base oil and 2-30wt% thickener relative to the total weight of the urea grease composition, wherein the thickener is selected from:

(1) a mixture comprising compound (a) and compound (b), the mixture containing 20-80 mol% of compound (a) relative to the total amount of compound (a) and compound (b);

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

(3) compound (c) alone,

wherein the respective compounds are represented by the following general 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, wherein the alkyl group should be required to include at least 20 mol% of oil-based components.

In the present invention, when the above-mentioned thickener is introduced into the lubricating base oil in an amount of 2-30 wt %, preferably 5-20 wt %, relative to the total weight of the urea grease composition, a lubricant with outstanding characteristics and performance can be obtained. Urea grease. When the content of the urea compound as a thickener is less than 2% by weight, the thickening effect is low and it is impossible to form grease. On the other hand, when the content of the urea compound as a thickener exceeds 30% by weight, the grease becomes too hard and thus cannot obtain a lubricating effect.

In the urea grease composition, when the ratio of the compound (a) in the mixture (1), relative to the total amount of the compound (a) and the compound (b), is less than 20 mol% or exceeds 80 mol%, then using the mixture will There was little effect, and there was no improvement in the noise reduction performance and the degree of oil separation.

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

The base oil of mineral origin may be a mineral oil, for example produced by solvent refining or hydrotreating.

Base oils of synthetic origin can be typical hydrocarbon oils such as C10-C50 hydrocarbon polymers such as alpha-olefin liquid polymers (poly(alpha-olefins)), ester-type synthetic oils, silicone oils and/or ether-type synthetic Oil. A mixture of these may also be used.

Examples of mineral oils which are conveniently available include those sold under the trade names "HVI", "MVIN" or "HMVIP" by companies of the Royal Dutch/Shell Group.

Polyalphaolefins and base oils of the type prepared by hydroisomerization of waxes, such as those sold under the trade name "XHVI" (trade mark) by companies of the Royal Dutch/Shell Group, may also 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 that can be conveniently used in the urea grease compositions of the present invention include zinc dithiocarbamates, for example, zinc diethyldithiocarbamate, zinc dipropyldithiocarbamate, zinc dithiocarbamate, Zinc butyl dithiocarbamate, zinc diamyl dithiocarbamate, zinc dihexyl dithiocarbamate, zinc didecyl dithiocarbamate, zinc diisobutyl dithiocarbamate, di Zinc (2-ethylhexyl) dithiocarbamate, zinc diamyl dithiocarbamate, zinc dilauryl dithiocarbamate, zinc dioctadecyl dithiocarbamate, and diphenyl Zinc dithiocarbamate, etc., and zinc xylyldithiocarbamate, zinc bis(dimethylphenyl)dithiocarbamate, zinc bis(ethylphenyl)dithiocarbamate, Zinc bis(propylphenyl)dithiocarbamate, zinc bis(butylphenyl)dithiocarbamate, zinc bis(pentylphenyl)dithiocarbamate, bis(hexylphenyl)dithiocarbamate Zinc substituted carbamate, zinc bis(octylphenyl)dithiocarbamate, zinc bis(nonylphenyl)dithiocarbamate, zinc bis(decylphenyl)dithiocarbamate, bis(decylphenyl)zinc dithiocarbamate, Zinc dialkylphenyl)dithiocarbamate, zinc bis(tetradecylphenyl)dithiocarbamate, and zinc bis(hexadecylphenyl)dithiocarbamate. Similarly, specific examples of zinc dithiophosphate include diethyl zinc dithiophosphate, dipropyl zinc dithiophosphate, dibutyl zinc dithiophosphate, dipentyl zinc dithiophosphate, dihexyl Zinc Dithiophosphate, Didecyl Zinc Dithiophosphate, Diisobutyl Zinc Dithiophosphate, Di(2-Ethylhexyl) Zinc Dithiophosphate, Diamyl Zinc Dithiophosphate, Dilauryl Zinc dithiophosphate, zinc bis(octadecyl)dithiophosphate, zinc diphenyldithiophosphate, and zinc bis(crelyl)dithiophosphate, bis(dimethylphenyl)dithiophosphate Zinc thiophosphate, zinc di(ethylphenyl)dithiophosphate, zinc di(propylphenyl)dithiophosphate, zinc di(butylphenyl)dithiophosphate, bis(pentylphenyl) ) zinc dithiophosphate, bis(hexylphenyl)zinc dithiophosphate, bis(heptylphenyl)zinc dithiophosphate, bis(octylphenyl)zinc dithiophosphate, bis(nonylphenyl) base) zinc dithiophosphate, bis(decylphenyl)zinc dithiophosphate, bis(dodecylphenyl)zinc dithiophosphate, bis(tetradecylphenyl)zinc dithiophosphate and zinc bis(hexadecylphenyl)dithiophosphate. Metallic elements such as S or P in the above organometallic zinc compounds can react with iron on the friction surface to form an extreme pressure film of iron phosphide or iron sulfide; the additive itself decomposes and interacts with other additives to form a protective film.

Furthermore, surprisingly, due to the synergistic effect of the aforementioned S-P type additives with the inventive urea thickener having outstanding penetration to the interface and adsorptive properties, the inventive urea grease composition exhibits outstanding lubricating performance.

The urea grease composition of the invention advantageously includes therein a molybdenum compound as an additive.

Specific examples of molybdenum compounds that can be conveniently used in the urea grease compositions of the present invention include molybdenum dithiocarbamates, for example, molybdenum diethyldithiocarbamate, molybdenum dipropyldithiocarbamate, molybdenum dithiocarbamate, Molybdenum butyl dithiocarbamate, molybdenum diamyl dithiocarbamate, molybdenum dihexyl dithiocarbamate, molybdenum didecyl dithiocarbamate, molybdenum diisobutyl dithiocarbamate, di Molybdenum (2-ethylhexyl)dithiocarbamate, molybdenum diamyldithiocarbamate, molybdenum dilauryldithiocarbamate, molybdenum dioctadecyldithiocarbamate, and diphenyl Molybdenum dithiocarbamate, etc., and molybdenum bis(tolyl)dithiocarbamate, molybdenum bis(dimethylphenyl)dithiocarbamate, molybdenum bis(ethylphenyl)dithiocarbamate Molybdenum, molybdenum bis(propylphenyl)dithiocarbamate, molybdenum bis(butylphenyl)dithiocarbamate, molybdenum bis(pentylphenyl)dithiocarbamate, bis(hexylphenyl)molybdenum dithiocarbamate Molybdenum dithiocarbamate, molybdenum bis(octylphenyl)dithiocarbamate, molybdenum bis(nonylphenyl)dithiocarbamate, molybdenum bis(decylphenyl)dithiocarbamate, Molybdenum (dodecylphenyl)dithiocarbamate, molybdenum bis(tetradecylphenyl)dithiocarbamate, and molybdenum bis(hexadecylphenyl)dithiocarbamate; and Molybdenum phosphate, such as diamyl molybdenum dithiophosphate, dipropyl molybdenum dithiophosphate, dibutyl molybdenum dithiophosphate, dipentyl molybdenum dithiophosphate, dihexyl molybdenum dithiophosphate, di Decyl molybdenum dithiophosphate, diisobutyl molybdenum dithiophosphate, di(2-ethylhexyl)molybdenum dithiophosphate, dipentyl molybdenum dithiophosphate, dilauryl molybdenum dithiophosphate, Molybdenum bis(octadecyl)dithiophosphate, molybdenum diphenyldithiophosphate, and molybdenum bis(crelyl)dithiophosphate, bis(dimethylphenyl)molybdenum dithiophosphate, bis( Ethylphenyl)molybdenum dithiophosphate, bis(propylphenyl)molybdenum dithiophosphate, bis(butylphenyl)molybdenum dithiophosphate, bis(pentylphenyl)molybdenum dithiophosphate, Di(hexylphenyl)molybdenum dithiophosphate, bis(heptylphenyl)molybdenum dithiophosphate, bis(octylphenyl)molybdenum dithiophosphate, bis(nonylphenyl)molybdenum dithiophosphate , bis(decylphenyl)molybdenum dithiophosphate, bis(dodecylphenyl)molybdenum dithiophosphate, bis(tetradecylphenyl)molybdenum dithiophosphate and bis(hexadecyl Phenyl)molybdenum dithiophosphate, and the molybdenum compound described in JP5-66435B1, are the reaction products of fatty oil, diethanolamine and molybdenum source.

The above-mentioned molybdenum compound is easily and actively adsorbed on the metal surface constituting the sliding surface, and is decomposed by the heat generated on the friction surface to produce MoO ₃ and MoS ₂ , and this MoS ₂ component diffuses into the metal to have an action mechanism of protecting the friction surface .

Furthermore, surprisingly, due to the synergistic effect of the chemical properties of these molybdenum compounds with the physicochemical properties of the urea thickeners of the invention, such as adsorption and permeability, the urea greases of the invention exhibit outstanding lubricating properties.

In order to improve the performance of the urea grease of the present invention, it is convenient to add additives such as antioxidant, anticorrosion agent and anti-extreme pressure agent therein.

For example, antioxidants include alkylphenols, hindered phenols, alkylamines, diphenylamines, and triazine antioxidants; corrosion inhibitors include calcium sulfonate, sodium sulfonate, barium sulfonate, and amino derivatives or metal carboxylates Salts; and extreme pressure agents include sulfurized oils or greases, sulfurized olefins, phosphoric acid esters, tricresyl phosphates, trialkylthiophosphates, triphenylphosphorothionates.

Lubricants for bearings advantageously contain the urea grease composition of the invention.

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

Furthermore, lubricants for sliding surfaces of machines in relative motion advantageously comprise the urea grease composition according to the invention.

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

The present invention further provides the use of the urea grease composition of the present invention as a noise-reducing grease composition, especially the use of the grease composition for reducing bearing noise.

Hereinafter, the present invention will be described with reference to examples, but these examples are not intended to limit the scope of the present invention.

Example

Example 1-5

Add MDI (diphenylmethane-4,4'-diisocyanate) and 60 parts by weight of base oil in the grease tank according to the compounding ratio shown in Table 1, and heat to nearly 50°C; The octylamine dispersed in 20 parts by weight of base oil was slowly added under rapid stirring. After about 10 minutes, the oleylamine dispersed in 20 parts by weight of base oil was added and stirring continued.

The temperature of the contents of the grease kettle will increase due to the reaction of the diisocyanate with the amine, and the reaction is then completed by heating to 168°C and holding at this temperature for about 30 minutes, followed by cooling to room temperature and then grinding on a three-roll mill Grease is obtained by processing in the machine.

Examples 6 and 7

Add MDI and 60 parts by weight of base oil according to the compounding ratio shown in Table 1 into the grease kettle, heat to about 50°C, and then dissolve the octane in 40 parts by weight of base oil after dissolving MDI. A mixture of amine and oleylamine was slowly added to the solution, and the mixture was stirred vigorously. The contents of the grease kettle were heated to 168°C and held at this temperature for about 30 minutes to complete the reaction, followed by cooling to room temperature and then processing in a three-roll mill to obtain grease.

Example 8-10

The compounding ratio is shown in Table 2. The grease of Example 8 was obtained by uniformly mixing 50 parts by weight of the grease of Example 1 and 50 parts by weight of the grease of Example 6 with a spatula.

The grease of Example 9 was obtained by uniformly mixing 50 parts by weight of the grease of Example 2 and 50 parts by weight of the grease of Example 6 with a spatula.

The grease of Example 10 was obtained by uniformly mixing 50 parts by weight of the grease of Example 3 and 50 parts by weight of the grease of Example 6 with a spatula.

Examples 11-16

Add MDI (diphenylmethane-4,4'-diisocyanate) and 60 parts by weight of base oil in the compounding ratio shown in Tables 3 and 4 to the grease tank, heat to about 50°C, and then dissolve After the MDI, 20 parts by weight of octylamine dissolved in the base oil was slowly added under rapid stirring. After about 10 minutes, the amines shown in Table 3 other than the octylamine mixed in the composition and 20 parts by weight of base oil were added, and stirring was continued.

The temperature of the contents of the grease kettle was raised by the reaction of the diisocyanate with the amine and the reaction was then completed by heating to 168°C and holding at this temperature for about 30 minutes, followed by cooling to 80°C and adding the The listed additives are then processed in a three-roll mill to obtain the grease.

Comparative example 1-15

Add the diisocyanate and 60 parts by weight of base oil in the compounding ratio shown in Table 5-7 to the grease tank, dissolve the diisocyanate at the following temperature, and slowly add the dispersed in 40 parts by weight under rapid stirring amines in the base oil.

The contents of the grease kettle were heated to 168°C and held at this temperature for about 30 minutes to complete the reaction, then cooled to room temperature and processed in a three-roll mill to obtain the grease.

In Comparative Examples 13-15, after cooling to room temperature, the additives listed in Table 7 were added, followed by processing in a three-roll mill to obtain grease.

In Table 1 and Table 3-7,

MDI is diphenylmethane-4,4'-diisocyanate; heating temperature is about 50°C

TDI is 2,4/2,6 (80%/20%) toluene (trilene)-4,4'-diisocyanate; heating temperature is about 30°C

TODI is 3,3'-bis(toluene)-4,4'-diisocyanate; the heating temperature is about 75°C.

The viscosities at 100°C of the oils shown in the implementation and comparative examples were 10.12 mm ² /s for mineral oil, 12.69 mm ² /s for alkyl diphenyl ether oil, and 12.70 mm for poly(α-olefin) oil. ² /s.

In the thickener mol% column of Table 1 and 2

(a) represents R ₁ NHCONHR ₂ NHCONHR ₁

(b) represents R ₃ NHCONHR ₂ NHCONHR ₃ and

(c) stands for 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) refers to the diurea compound of embodiment 1,

(2) refers to the diurea compound of embodiment 2,

(3) refers to the diurea compound of Example 3, and

(4) refers to the diurea compound of Example 6.

Additives in Table 3, Table 4 and Table 7:

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

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

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

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

Additive E is a molybdenum complex compound described in JP5-66435B1,

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

Additive G is obtained through 2,4-bis(n-lipoctyl)-6-(4-hydroxy-3,5-di-t-butylamine)-1,3,5-triazine and octyldiphenyl A slurry formed by compounding amine with mineral oil at a concentration of 50% in a ratio of 1:2.

Table 4

table 5

Comparative example 1 2 3 4 5 6 MDI(g) 11.08 7.95 12.93 11.88 - -

Comparative example 1 2 3 4 5 6 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 120s 52 56 2229 ＞10000 151 191

Table 7

The properties of the examples and comparative examples in the table were tested by using the following methods.

Consistency: JIS K2220

Dropping point: JIS K2220

Oil separation degree: JIS K2220 method at 150°C for 24 hours.

Noise test: A bearing noise test was carried out for each grease by using an NSK noise tester (obtained from NSK LTD) according to the method described in JP532357B1.

Bowden Friction Test: The coefficient of friction is measured using a device having the following technical parameters, which evaluates the friction of the friction surface between a reciprocating bed and a pin (pin) that receives a load perpendicular to the plate mounted on the bed, the device There is a mechanism for applying a load perpendicular to the bed.

1. Form: reciprocating sliding friction tester

2. Test piece: fixed edge: steel ball or rod

Movement side: steel plate specification about 3×40×100mm

3. Sliding speed: 0.05-20mm/s

4. Sliding distance: 20-50mm

5. Load: 0.1-10Kg

6. Temperature: room temperature to 200°C

7. Driving method: Feed screw sliding, lead 2mm

8. Drive motor: AC servo motor 400W

These experimental results show that:

(1) According to the present invention, a urea grease composition having outstanding noise reduction and lubricating properties can be produced by using ordinary grease production equipment without requiring a special device for dispersing a thickener such as a kneader or an autoclave ;

(2) The urea grease composition according to the present invention has an outstanding consistency coefficient, and a small amount of thickener becomes viscous grease; and

(3) The urea grease according to the present invention has a high dropping point and does not exhibit oil separation at high temperatures.

Claims (10)

1. urea grease composition, it comprises lubricating base oil and with respect to the thickening material of the 2-30wt% of the gross weight of urea grease composition, wherein said thickening material is selected from:

(1) mixture of inclusion compound (a) and compound (b), this mixture contains the compound (a) with respect to the 20-80mo1% of the total amount of compound (a) and compound (b);

(2) by mixing cpd (c) and the formed mixture of mixture (1); Or

(3) independent compound (c),

Wherein compound is represented by following general formula separately:

(a)R ₁NHCONHR ₂NHCONHR ₁；

(b) R ₃NHCONHR ₂NHCONHR ₃With

(c)R ₁NHCONHR ₂NHCONHR ₃，

R wherein ₂Be the diphenylmethyl alkyl, R ₁Be C6-10 saturated alkyl and R ₃Be the saturated and/or unsaturated alkyl of C14-40, wherein unsaturated alkyl accounts for R ₃At least the 20mol% of alkyl.

2. according to the urea grease composition of claim 1, wherein unsaturated alkyl accounts for R ₃At least the 30mol% of alkyl.

3. according to the urea grease composition of claim 1, wherein oil base accounts for R ₃At least the 20mol% of alkyl.

4. according to each urea grease composition of claim 1-3, wherein said composition further comprises the zn cpds as additive.

5. according to the urea grease composition of claim 4, wherein said zn cpds is selected from zinc dithiocarbamate and zinc dithiophosphate.

6. according to each urea grease composition of claim 1-3, wherein said composition further comprises the molybdenum compound as additive.

7. according to the urea grease composition of claim 6, wherein said molybdenum compound is selected from molybdenum dithiocarbamate, the molybdenum mixture of the reaction product in molybdenum dithiophosphate and fatty oil, diethanolamine and molybdenum source.

8. according to each urea grease composition of claim 1-3, wherein thickening material exists with the amount with respect to the 5-20wt% of the gross weight of urea grease composition.

9. the method for lubricating bearings, this method comprise utilizes each urea grease composition filled bearing of claim 1-8.

10. lubricate the method for the slipping plane of the machine in relative movement, this method comprises utilizes each the lubricated described slipping plane of urea grease composition of claim 1-8.