KR20120005632A - Urea grease composition for constant velocity joints - Google Patents

Abstract

PURPOSE: A urea grease composition for a constant velocity joint is provided to maximally use extreme pressure and abrasion properties for securing the mechanical stability of grease. CONSTITUTION: A urea grease composition for a constant velocity joint contains 0.5-5wt% of melamin ecyanurate component, 0.5-7wt% of tricresyl phosphate, 0.2-6wt% of 2-ethylhexyl zinc dithiophsphate, and 0.5-6wt% of sulfurized bis(dibutyl carbamodithioato)di-mu-oxodioxodi molybdenum. The urea grease composition is marked with chemical formula 1. In the chemical formula 1, R1 and R2 are aromatic hydrocarbon with 6-7 carbon, a cyclohexyl group with 6-7 carbons, or aliphatic hydrocarbon with 6-20 carbons.

Description

Urea Grease Composition for Constant Velocity Joints}

The present invention relates to a urea grease composition for a constant velocity joint, and more particularly, to exhibit the effects of extreme pressure and wear characteristics to the maximum, thereby reducing the wear of machinery and parts without impairing the mechanical stability of grease, thereby making a constant velocity joint or ball for automobiles. A urea grease composition for constant velocity joints useful in the joints and steel industry and other industrial gears and bearings.

Typically, a motor vehicle is driven by power transmitted from an engine to a wheel through a drive shaft. At this time, the wheel is moved left and right by the steering wheel (steering wheel) responsible for the change of direction, the axis that transmits this movement (power) is a constant velocity joint. This constant velocity joint is a very important part of the car, which is connected to the drive shaft between the car engine and the wheels. The constant velocity joint is made of a metal-to-metal connection part, so that grease is injected into the connection part to prevent abrasion due to friction of the metal and sealed with a rubber boot.

As for grease, the adoption of a constant velocity joint up to a four-wheeled vehicle is increasing rapidly. In particular, as the driving conditions of the constant velocity joint become more difficult by reducing the size and weight of the constant velocity joint in order to increase the output of the front wheel drive vehicle, the durability of the constant velocity joint is increasingly required. For example, constant velocity joints are connected to turbo engines or high power engines, and are exposed to high speeds, high loads and high angles, resulting in rapid temperature rise due to internal heat generation. It should be able to cope with the above speed and torque increase, have excellent durability at high temperature, and have the capability to effectively prevent wear of machinery and components by maximizing wear and extreme pressure performance. Maximizing wear and extreme pressure performance is also necessary from the standpoint of improving the durability of constant velocity joints and preventing aging of the lubricating grease itself, which promotes aging of the grease itself due to excessive load (extreme pressure) and wear due to temperature rise. As a result, the service life of the constant velocity joints is severely shortened.

On the other hand, in the steel business, there is a strong demand for high-quality grease with long-term lubricity and high heat resistance due to the necessity of preventing environmental pollution, saving resources, saving energy, and labor costs. The performance of steel mills varies slightly depending on various conditions. I need Greece.

According to Korea Patent Publication No. 0562129, "base oil 68 ~ 92.8% by weight; 5 to 25% by weight of a urea thickener represented by Formula 1; 1.0 to 2.0 wt% molybdenum dialkyldithiocarbamate; Zinc dialkyldithiophosphate 0.5-1.5 wt% organomolybdenum complex compound 0.1-1.0 wt%; 0.1 to 1.0% by weight of 2,5-dimercapto-1,3,4-thiadiazole; And 0.5 to 1.5% by weight of a sulfur-based fatty ester.

However, the use of a combination of extreme pressure additives and anti-wear agents improves durability and water resistance, improves extreme pressure and friction resistance, and increases axial force reduction efficiency. Due to the significant impact, high water usage, and contact with scaled environments, there was a lack of wear resistance, friction and sealing properties.

Korea Patent Registration No. 0562129 “Grease composition for constant velocity joint”

Accordingly, the present invention is to fundamentally solve the conventional problems as described above, showing the effects of extreme pressure and wear characteristics to the maximum, so that the mechanical stability of the grease can be reduced without damaging the wear of the machine and parts, the constant velocity joint for automobile The aim is to provide urea grease compositions for constant velocity joints useful in ball joints and other industrial gears and bearings, including the steel industry.

In order to achieve the above object, the present invention provides a urea grease composition for use in a constant velocity joint: melamine cianurate, tricresyl phosphate, zinc dialkyldithiophosphate (2) to urea grease. -ethylhexyl zinc dithiophosphate), an organic molybdenum compound of sulfide-ized bis (dibutylcamabothiothio) It is characterized by comprising.

At this time, the melamine cyanurate component is 0.5 to 5.0% by weight based on the whole grease, 0.5 to 7% by weight of the tricresyl phosphate component, 0.2 to 6% by weight of the zinc dialkyldithiophosphate component, and sulfurized bis (die Butyl camoda thiothio) di-, μ,-oxodioxodiomolybdenum is characterized by consisting of 0.5 to 6% by weight.

In addition, urea-based grease thickener is a urea compound represented by the following formula

Formula 1)

In the formula, R1 and R2 are each independently or at the same time characterized in that an aromatic hydrocarbon having 6 or 7 carbon atoms, cyclohexyl group having 6 or 7 carbon atoms or aliphatic hydrocarbon having 6 to 20 carbon atoms.

On the other hand, the terms or words used in the present specification and claims are not to be construed as limiting the ordinary or dictionary meanings, the inventors should use the concept of the term in order to explain the invention in the best way. It should be interpreted as meanings and concepts corresponding to the technical idea of the present invention based on the principle that it can be properly defined. Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all of the technical ideas of the present invention, and various alternatives may be substituted at the time of the present application. It should be understood that there may be equivalents and variations.

As described in the above configuration and operation, the present invention exhibits the effects of extreme pressure and wear characteristics to the maximum, and can reduce the wear of machinery and parts without compromising the mechanical stability of grease. And other industrial gears and bearings.

The present invention relates to a urea grease composition for a constant velocity joint.

The grease composition according to the present invention is a melamine cyanurate, tricresyl phosphate, tricresyl phosphate, 2-diethylhexyl zinc dithiophosphate, or an organic molybdenum compound in urea grease. Bis (dibutylcamabosaithioeto) di-, μ, -oxodioxodiomolybdenum (molybdenum, bis (dibutylcarbamodithioato) di-m-oxodioxodi-, sulfurized). The urea grease used in the present invention may use any of conventional diurea grease, triurea grease, tetraurea grease and polyurea grease.

As the base oil of the grease composition of the present invention, general mineral oil, synthetic oil, or mixed oil may be used, and may contain 2 to 35% by weight of urea, which is a thickener. At this time, the melamine cyanurate of the four additives added to the grease composition is used in 0.5 to 5% by weight, more preferably in 1 to 3% by weight. If the amount used is less than 0.5% by weight, there is no effect of increasing wear and extreme pressure performance.

In addition, among the four additives added to the grease composition, tricresyl phosphate is used in an amount of 0.5 to 7% by weight, more preferably in an amount of 2 to 3% by weight. If the amount is less than 0.5% by weight, there is no effect of increasing wear and extreme pressure performance, and when the amount is more than 7% by weight, there is no further effect.

Of the four additives added to the grease composition, zinc dialkyldithiophosphate is used in an amount of 0.2 to 6 wt%, more preferably in an amount of 2-3 wt%. If the amount is less than 0.2% by weight, there is no effect of increasing wear and extreme pressure performance, and when the amount is more than 6% by weight, there is no further effect.

In addition, among the four additives added to the grease composition, sulfurized bis (dibutylcamathioiso) di-, μ, -oxodioxodiomolybdenum is used in an amount of 0.5 to 6 wt%, and 1 to 3 wt% More preferably used as. If the amount used is less than 0.5% by weight, there is no effect of increasing wear and extreme pressure performance. If the amount is more than 6% by weight, there is no further effect.

At this time, the grease composition of the present invention can be used by further adding an antioxidant, a rust preventive agent, a polymer and other components as necessary in addition to the above composition.

Hereinafter, the present invention will be described in detail with reference to the following examples. At this time, the conventional grease used in the present invention prior to the embodiment is a urea-based compound represented by the following formula and the manufacturing method is as follows.

Formula 1)

Wherein R 1 and R 2 are each independently or simultaneously an aromatic hydrocarbon having 6 or 7 carbon atoms, a cyclohexyl group having 6 or 7 carbon atoms, or an aliphatic hydrocarbon having 6 to 20 carbon atoms. The urea-based grease thickener of Formula 1 may be prepared by reacting 1 equivalent of diisocyanate with 2 equivalents of alkyl, cyclo or arylamine in the presence of a lubricating base oil. In this case, the urea-based grease thickener may be prepared by varying the type of amine used as a raw material, or by adjusting the mixing ratio of amines to be mixed when using more amines. As the amine used in the present invention, aliphatic amines and cycloaliphatic amines, and mixtures thereof can be used. Here, examples of the diisocyanate may be 4,4-methylenebis (phenylisocyanate), and examples of the amine include an aromatic amine having 6 to 7 carbon atoms or cyclohexylamine, or an aliphatic amine having 6 to 20 carbon atoms. Can be used

<Examples 1-6 and Comparative Examples 1-8>

According to the composition of Table 1 and Table 2, the additive was added to the conventional grease prepared in Preparation Example, and the three-roll milling of the grease composition of each of Examples and Comparative Examples. The base oil used in the Example and the comparative example was refined mineral oil whose viscosity is 17 cSt at 100 degreeC.

The four-part wear resistance, four-part fusion load, oxidation stability, reason degree, low temperature torque, etc. of the grease compositions prepared in Examples and Comparative Examples were evaluated by the following test methods, and the results are shown in Tables 1 and 2 below. It was.

(1) Four Ball Wear

4-Ball Wear Diameter was measured according to ASTM D 2226.

Speed: 1200 rpm

Load: 40 kgf

Temperature: 75 ℃

Time: 60 minutes

(2) Four Ball Extreme Pressure

Four Ball Fusion Pressure (Four Ball Extreme Pressure) was measured according to ASTM D 2596.

Rotational Speed: 1820 rpm

Load: step by step

Time: 10 seconds

(3) Low Temperature Torque

Low temperature torque was measured according to KS M 2130.

Temperature: -30 ℃

(4) Oil Separation

Oil Separation was measured according to KS M 2050.

(5) Oxidation Stability

Oxidation Stability was measured according to KS M 2049.

(6) Dropping Point

Dropping Point was measured according to KS M ISO 2176.

(6) Working Stability

Working Stability was measured according to KS M ISO 2137.

Mixed: 100,000

The four-part wear resistance, four-part fusion load, oxidation stability, reason degree, low temperature torque, etc. of the grease compositions prepared in Examples and Comparative Examples were evaluated by the following test methods, and the results are shown in Tables 1 and 2 below. It was.

(1) Four Ball Wear

4-Ball Wear Diameter was measured according to ASTM D 2226.

Speed: 1200 rpm

Load: 40 kgf

Temperature: 75 ℃

Time: 60 minutes

(2) Four Ball Extreme Pressure

Four Ball Fusion Pressure (Four Ball Extreme Pressure) was measured according to ASTM D 2596.

Rotational Speed: 1820 rpm

Load: step by step

Time: 10 seconds

(3) Low Temperature Torque

Low temperature torque was measured according to KS M 2130.

Temperature: -30 ℃

(4) Oil Separation

Oil Separation was measured according to KS M 2050.

(5) Oxidation Stability

Oxidation Stability was measured according to KS M 2049.

(6) Dropping Point

Dropping Point was measured according to KS M ISO 2176.

(6) Working Stability

Working Stability was measured according to KS M ISO 2137.

Mixed: 100,000

Table 1 (Invention experiment here)

Table 2 (Comparative Example Experiment)

As can be seen in Table 1 and Table 2, when comparing the data of the comparative example with the data of the example, the grease composition of the comparative example is 20 to 30% compared to the example of the four-wheel wear resistance expressed by the four-ball wear diameter It can be seen that the performance of the sand gloss fusion load is greatly reduced by around 50%, and it is also found that the performance is lowered by about 10% around the same even in the tests of low temperature torque, reason, oxidation stability, dropping point, and miscibility. The grease composition of the embodiment of the present invention produced a much superior effect on the four-sided wear resistance, especially four-sided fusion load than the composition of the comparative example.

As such, the present invention exhibits the effects of extreme pressure and wear characteristics to the maximum, thereby reducing the wear of machinery and components without compromising the mechanical stability of grease, such as automotive constant velocity joints, ball joints, and other industrial gears or bearings, including the steel industry. Provides a useful effect.

It is apparent to those skilled in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. It is therefore intended that such variations and modifications fall within the scope of the appended claims.

Claims (3)

In urea grease compositions used in constant velocity joints:
Melamine cianurate, tricresyl phosphate, 2-diethylhexyl zinc dithiophosphate, and sulfonated bis (dibutylcarboxaysy) as an organic molybdenum compound in urea grease Oeto) diurea, a composition comprising a di-, μ, -oxodioxodiomolybdenum (molybdenum, bis (dibutylcarbamodithioato) di-m-oxodioxodi-, sulfurized). The method of claim 1,
The melamine cyanurate component is 0.5 to 5.0% by weight based on the whole grease, 0.5 to 7% by weight of the tricresyl phosphate component, 0.2 to 6% by weight of the zinc dialkyldithiophosphate component, and sulfurized bis (dibutyl) The urea grease composition which consists of 0.5-6 weight% of camabodithioate) di-, (micro),-oxodioxo dimolybdenum. The method of claim 1,
The urea-based grease is a urea-based compound represented by the following formula
Formula 1)

Wherein R 1 and R 2 each independently or simultaneously comprise an aromatic hydrocarbon having 6 or 7 carbon atoms, a cyclohexyl group having 6 or 7 carbon atoms, or an aliphatic hydrocarbon having 6 to 20 carbon atoms.