SK286548B6 - Urea grease composition - Google Patents

Abstract

A urea grease composition and gears containing such composition, which composition comprises a urea grease and as additives: (A) a molybdenum dialkyldithiocarbamate sulfide represented by formula (I), wherein R1 and R2 each independently represents a group selected from the group consisting of alkyl groups having from 1 to 24 carbon atoms; m is 0 or an integer of from 1 to 3; and n is an integer of from 1 to 4; provided that the sum of m and n is 4, and (B) a triphenyl phosphate represented by formula (II).

Description

Technical field

The present invention relates to urea-based petrolatum compositions and gears containing such compositions.

BACKGROUND OF THE INVENTION

The price of oil has risen sharply after the so-called oil shock and ideas for saving resources and energy have consistently emerged in each sector, reflecting its impact.

Compact and lightweight general motor vehicles have been developed in the motor vehicle industry and the number of vehicles using constant speed links (CVS - constant velocity joints) has increased. CVJ is also used in all-wheel-drive vehicles and in four-wheel-drive vehicles with independent suspension type, and demand continues to grow. A CVJ, also called a universal constant speed joint, is a joint that transmits rotation while maintaining constant angular velocity and torque, and has different types depending on different applications. Lubricants used on CVJs are exposed to more demanding conditions as the motor vehicle achieves higher power and higher speed and the CVJs themselves become compact, and therefore grease is required to reduce friction and wear of sliding parts. In addition, a sealing element is required to prevent grease leakage and foreign objects and water from entering the outside. Chloroprene rubber and polyester resins are generally used as the material.

Grease, which is excellent in reducing friction and increasing wear resistance, suppresses the vibration and noise of the vehicle body during starting and acceleration and while driving. Moreover, the durability of the sealing element can be increased due to the lowering effect. However, excessive temperature increase increases the aging of the sealing element and degradation of the lubricant significantly shortens the life of the CVJ.

On the other hand, the continuous operation of mechanical equipment has further developed in the steel industry. With the technical revolution, there has been a strong demand for high product quality, improvements in production process capacity, ensuring instrument reliability, and the like. Lubrication conditions are very demanding as the greases used in these mechanical devices are in difficult environments, i.e. at high temperature, in contact with water, with a high potential for foreign substances such as lime scale and the like to be exposed to twenty-four. hours a day. Grease is required which has excellent sealing resistance and which reduces friction and wear in order to prolong the life of mechanical parts and prevent sudden failure of the device. Furthermore, the components to be lubricated in the mechanical engineering industry include machine tools and the like that suffer from considerable friction, and excessive wear causes a reduction in the accuracy of the machine, so that mechanical parts must be replaced. As described, reducing friction and wear is an important object of the present invention.

Lithium based greases using sulfur-based compounds, such as sulfur fat and oil, sulfur olefins and the like, lead naphthenate, metal dithiophosphates, metal dithiocarbamate additives, and the like, have therefore been advantageously used in the described components requiring lubrication. More recently, lithium complex greases and urea greases, which are better in heat resistance than lithium greases, have been increasingly used.

As representative of the prior art, U.S. Pat. No. 4,514,312 petrolatum utilizing aromatic amine phosphate as an organic additive containing no sulfur in urea petrolatum. Further, U.S. Pat. No. 4,840,740 discloses petrolatum comprising urea petrolatum, an organic molybdenum compound and zinc dithiophosphate. Japanese Patent Publication (JP-B) no. No. 04-34590 (1992) discloses urea petrolatum containing, as an essential component, a high pressure additive based on sulfur and phosphorus consisting of the following components:

1. Molybdenum sulfide dialkyldithiocarbamate a

2. one or a combination of two or more components selected from the group consisting of sulphurized fat and oil, sulphurized olefin, tricresyl phosphate, trialkylthiophosphate and zinc dialkyldithiophosphate.

Although it is recognized that some of the prior art greases have the effects of reducing friction and wear, full satisfaction has not been achieved. Moreover, it is a disadvantage that the sealants deteriorate at high temperature. For example, the aromatic amine phosphate and lead naphthenate degrade polyester resins and the sulfurized fat and oil degrades chloroprene rubber and the sulfurized olefin significantly degrades chloroprene rubber and polyester resins.

In addition, Japanese Patent Application (JP-A) no. No. 08-157859 (1996) discloses the use of molybdenum sulfide dialkyldithiocarbamate and triphenylphosphoricionate as an additive, and Japanese Patent Application (JP-A) No. 08/7859. 62-2275197 (1987) discloses the use of 12-hydroxy fatty acid lithium soap, a lithium phosphate formed from a phosphate such as trimethyl phosphate or triphenyl phosphate, as a thickening agent. Further, Japanese Patent Application (JP-A) no. 03-231993 (1991) discloses a petrolatum composition utilizing a phosphate oil in a urea compound.

SUMMARY OF THE INVENTION

The present invention relates to urea petrolatum which is excellent in friction and wear resistance properties and also has good compatibility with a sealant such as chloroprene rubber and polyester resin. In particular, the present invention relates to a urea grease composition suitable for application to parts to be greased with petroleum jelly, such as constant speed joints, ball joints and ball bearings in motor vehicles and bearings and gears of various industrial equipment such as steel and industrial machines and machine tools.

The present invention relates to a urea petrolatum composition comprising urea petrolatum and as additive (A) a dialkyl di-dithiocarbamate molybdenum sulfide, which is represented by the formula:

NC S- 2θ2θ | γ | δη _; wherein R ¹ and R ² each independently represent a group selected from the group consisting of alkyl groups of 1 to 24 carbon atoms; m is 0 or an integer from 1 to 3; and n is an integer from 1 to 4; provided that the sum of m and n is 4 and (B) triphenylphosphate, which is represented by the formula:

The compounds corresponding to component (A) above have a high melting point. Examples of such compounds include dietylsulfid-molybdenum dithiocarbamate, dibutyl-molybdenum dithiocarbamate, molybdenum diizobutylsulfidditiokarbamát, di (2-ethylhexyl) sulfide-molybdenum dithiocarbamate, diamyl sulfide-molybdenum dithiocarbamate, diisoamyl sulfide-molybdenum dithiocarbamate, dilauryl sulfide-molybdenum dithiocarbamate, molybdenum distearylsulfidditiokarbamát. They are preferably admixed in powder form and the amount added is from 0.5 to 10% by weight, preferably from 0.5 to 5% by weight, based on the total weight. When the amount added is less than 0.5% by weight, the effect of the improvement in frictional and wear resistance is generally insufficient, and when more than 10% by weight is added, in most cases no further improvement is achieved.

Since triphenylphosphate has a melting point of 50 ° C and is solid at room temperature, it is preferred that the powder is mixed with a basic petrolatum at a temperature of at least 50 ^° C. The amount of component (B) is preferably from 0.1 to 10% by weight, 0.1 to 5% by weight based on the total weight. When less than 0.1% by weight is used, it is generally not possible to achieve an improvement in friction and wear resistance, and when more than 10% by weight is used, it is usually not possible to obtain a higher lubricity.

For the urea compound, any known urea-type thickener can be used. For example, dimurea, trimurea and tetramurea may be used.

Mineral oil and / or synthetic oil may be used as the base oil. When a urea compound is used as a thickening agent, it is preferably applied in an amount of from 2 to 35% by weight based on the total weight of the base oil and the urea compound.

Various additives such as antioxidants, anticorrosive agents, high pressure reagent, polymers and the like can also be added to the composition of the present invention.

The urea petrolatum compositions of the invention are particularly suitable for use in gears, more specifically in constant speed joints. Thus, the present invention further relates to gears, more particularly to constant speed joints containing such petrolatum.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be specifically described by way of examples and comparative examples, but is not to be construed as limited to the examples given. Additives were added to the baseline grease at mixing ratios according to Tables 1 to 5 (all percentages by weight). The mixtures were processed in triple-roll mills to give petrolatum according to the Examples and Comparative Examples.

Vaseline formulations are described later. Purified mineral oil having a viscosity of 15 mm ² / s at 100 ° C was used as the base oil.

I. Vaseline based on dimurea

One mole of diphenylmethane-4,4'-diisocyanate and 2 moles of octylamine were reacted in the base oil, and the obtained urea compound was dispersed evenly to give petrolatum. The amount of urea compound was 10% by weight based on the total weight of the base oil and the urea compound.

Vaseline based on tetramurea

Two moles of diphenylmethane-4,4'-diisocyanate, 2 moles of octylamine and 1 mole of ethylenediamine were reacted in the base oil and the urea compound obtained was dispersed evenly to give petrolatum. The amount of urea compound was 15% by weight based on the total weight of the base oil and the urea compound.

Vaseline based on lithium complex

The hydrogenated beaver oil fatty acid was dissolved in the base oil to which aqueous lithium hydroxide solution was added to neutralize and the mixture was dehydrated during the reaction. After dehydration, azealic acid was added. The reaction was carried out with an aqueous solution of lithium hydroxide in an amount necessary for neutralization. Lithium azealate and lithium 12-hydroxystearate were mixed and uniformly dispersed to give petrolatum. The amount of 12-hydroxystearate as a thickener was 7.5% by weight and the amount of lithium azealate was 2.5% by weight based on the total weight of the base oil and thickener.

For friction coefficient, water resistance and sealant compatibility, the following test was performed with the results shown in the table.

(1) Friction coefficient

The friction coefficient after 15 minutes was measured under the following conditions using a Falex tester (according to IP / 241/69).

Rotation speed: 290 rpm load: 890 N (200 lb) temperature: Time: room temperature 15 minutes Amount of Vaseline: about 1 g of petroleum jelly was applied to the test piece

(2) Wear resistance

According to the 4-ball wear test according to ASTM D2226

Rotation speed:

load:

temperature:

Time:

1200 rpm

392N (40kgf) ° C minutes

Compatible with sealant

Sealants that were of chloroprene rubber or polyester resin were immersed in the appropriate grease compositions and tested under the following conditions according to the physical test for vulcanized rubber according to JIS K6301. The tensile strength and elongation before and after the test were measured and the percentage change was obtained.

Temperature: 140 ° C

Immersion time: 96 hours

Table 1

Example 1 2 3 4 statement Basic Vaseline Urea Vaseline Tetramurea Vaseline 96.5 94.5 96.0 94.0 A-1 ¹ 3.0 3.0 5.0 (% -Wt.) additive A-2 ² 5.0 B ³ 0.5 0.5 1.0 1.0 Together 100.00 100.00 100.00 100.00 Coefficient of friction (μ) 0,092 0,089 0,090 0,084 Wear resistance (mm) 0.42 0.40 0.41 0.41 The result Chloroprene Tensile strength change (%) -6.4 -5.3 +1.3 -5.3 test rubber Change in extension (%) -2.9 +0.9 +18.7 +5.2 Polyester Tensile strength change (%) +2,5 -4.5 -20.7 -6.8 vica Change in extension (%) +14.0 -7.8 -15.1 -11.4

Table 2

Example 5 6 7 statement Basic- Zelina Thiourea petrolatum Tetramurea Vaseline 95.0 96.0 93.0 (% -Wt.) additive A-1 ⁴ A-2 ⁵ B ⁵ 3.0 2.0 2.0 1.0 1.0 2.0 3.0 2.0 Together 100.00 100.00 100.00 Friction coefficient (μ) Wear resistance (mm) 0,083 0.41 0,088 0.42 0,082 0.38 The result test Chloroprene rubber Change in tensile strength (%) Change in elongation (%) -6.3 +5.6 -8.1 +5.2 -3.9 +4.1 Polyester ca Change in tensile strength (%) Change in elongation (%) -14.6 -1.9 -16.5 -10.6 -4.8 -5.9

¹ A-1 is a molybdenum sulfide dialkyldithiocarbamate, MOLYVANA A, available from Vanderbilt Co.

² A-2 is a dialkyldithiocarbamate molybdenum sulfide, SAKURALUBE 600, available from Asahi Denka Kogyo KK

³ B is triphenylphosphate ⁴ A-1 is molybdenum sulfide dialkyldithiocarbamate, MOLYVANA A, available from Vanderbilt Co.

⁵ A-2 is a dialkyldithiocarbamate molybdenum sulfide, SAKURALUBE 600, available from Asahi Denka Kogyo KK

⁶ B is triphenylphosphate

Table 3

Comparative example 1 2 3 4 5 Basic grease Thiourea Vaseline Lithium complex petroleum jelly 99.5 98.0 97.0 98.0 95.0 Formulation (% -wt.) additive Al ⁷ A-2 ⁸ B ⁹ Vanlube 592 ¹⁰ Lubrizol 1360 ¹¹ Lubrizol 5006 ¹² Lubrizol 5340L ¹³ Tri-Phosphate Dailube L-30 ¹⁴ 0.5 2.0 3.0 2.0 3.0 2.0 Together 100.00 100.00 100.00 100.00 100.00

Table 4

Comparative example 6 7 8 9 10 Basic grease Thiourea Vaseline Lithium complex petroleum jelly 99.5 94.0 95.0 96.5 95.0 statement (% -Wt.) additive Al ¹⁵ A-2 ¹⁶ B ¹⁷ Vanlube 592 ¹⁸ Lubrizol 1360 ¹⁹ Lubrizol 5OO6 ²⁰ Lubrizol 5340L ²¹ Tricresyl phosphate Dailube L-30 ²² 3.0 1.0 0.5 3.0 1.0 2.0 3.0 2.0 3.0 0.5 3.0 2.0 Together 100.00 100.00 100.00 100.00 100.00

Table 5

Comparative example 1 2 3 4 5 Friction coefficient (μ) Wear resistance (mm) 0,144 0.56 0,126 0.58 0,116 0.44 0,120 0.51 0,103 0.41 Test result Chloroprene rubber Change in tensile strength (%) Change in elongation (%) -5.3 -0.4 -12.1 -4.1 -18.4 -2.2 -9.4 +29.5 -16.9 +34.1 Polyester resin Change in tensile strength (%) Change in elongation (%) -1.9 -3.2 -14.2 +8.8 -4.9 -0.5 -36.0 -38.6 +2.7 +34.3

⁷ Al is molybdenum sulfide dialkyldithiocarbamate, MOLYVANA A, available from Vanderbilt Co.

⁸ A-2 is a dialkyldithiocarbamate molybdenum sulfide, SAKURALUBE 600, available from Asahi Denka Kogyo KK

⁹ B is triphenylphosphate.

¹⁰ Vanlube 592 is a trade name of RT Vanderbilt Co. Inc. and a viscous liquid (190 SUS / 100 ° C) containing an aromatic amine phosphate.

¹¹ Lubrizol 1360 zinc dialkyldithiophosphate.

¹² Lubrizol 5006 is a sulfurized fat and oil.

¹³ Lubrizol 5340L is a sulfur olefin.

¹⁴ Dailube L-30 is lead naphthenate from Dainippon Ink and Chemicals, Inc.

¹⁵ Al is molybdenum sulfide dialkyldithiocarbamate, MOLYVANA A, available from Vanderbilt Co.

¹⁶ A-2 is a dialkyldithiocarbamate molybdenum sulfide, SAKURALUBE 600, available from Asahi Denka Kogyo KK

¹ 'B is triphenylphosphate.

¹⁸ Vanlube 592 is a trade name of RT Vanderbilt Co. Inc. and a viscous liquid (190 SUS / 100 ° C) containing an aromatic amine phosphate.

¹⁹ Lubrizol 1360 zinc dialkyldithiophosphate.

²⁰ Lubrizol 5006 is a sulfurized fat and oil.

²¹ Lubrizol 5340L is a sulfur olefin.

²² Dailube L-30 is lead naphthenate from Dainippon Ink and Chemicals, Inc.

Table 6

Comparative example 6 7 8 9 10 Friction coefficient (μ) Wear resistance (mm) 0,123 0.41 0,119 0.42 0,123 0.44 0,119 0.40 0,117 0.41 Test result Chloroprene rubber Change in tensile strength (%) Change in elongation (%) -53.0 -31.5 -74.8 -81.3 -13.2 +23.9 -10.0 0.8 -16.6 +7.6 Polyester resin Change in tensile strength (%) Change in elongation (%) -17.7 -8.2 -52.7 -54.0 -43.2 -70.6 +9.0 +23.3 +7.2 +28.8

The friction coefficients in Examples 1 to 7 are all smaller than those of Comparative Examples 1 to 10. With respect to water resistance, Comparative Examples 5, 6, 7, 9 and 10 provide the same degree of good results as the Examples of the invention. However, these comparative examples are worse in compatibility with chloroprene rubber and / or polyester resin.

For example, Comparative Example 5 gives a major change in the elongation of chloroprene rubber and polyester resin. Comparative Example 6 gives a great change in tensile strength and elongation of chloroprene rubber and polyester resin. Comparative Examples 9 and 10 give a relatively large change in the elongation of the polyester resin. Examples 1 to 7 give an excellent coefficient of friction and wear resistance, as well as excellent compatibility with the sealant of chloroprene rubber and polyester resin.

The petrolatum of the present invention has a low coefficient of friction and is excellent in wear resistance. As a result, the vibration and noise of CVJ motor vehicles are reduced. In addition, the grease of the present invention reduces friction in ball joints and wheel bearings of motor vehicles and other various industrial machines and can extend the life of machine components.

The petrolatum of the present invention is excellent in the property of compatibility with chloroprene rubber and polyester resin and slows down the degradation of the device sealant even at high temperatures.

Claims (5)

PATENT CLAIMS 1. A urea-based petroleum jelly composition comprising urea petrolatum and, as additives (A), a dialkyldithiocarbamate molybdenum sulfide, which is represented by the formula: NC S - Mo2O _m S _n R ² £ -J 2 wherein R ¹ and R ² each independently represent a group selected from the group consisting of alkyl groups of 1 to 24 carbon atoms; m is 0 or an integer from 1 to 3; and n is an integer from 1 to 4; provided that the sum of m and n is 4 and (B) triphenylphosphate, which is represented by the formula: The urea-based vaseline composition according to claim 1, characterized in that said component (A) and said component (B) are mixed in an amount of from 0.5 to 10% by weight with respect to the total weight of the urea-based petroleum composition. The urea grease composition according to claim 1 or 2, wherein said urea grease comprises a base oil and a urea compound as a thickener, wherein the proportion of urea compound is from 2 to 35% by weight based on the total weight of the base oil and compound. urea. Transmission comprising a urea-based petrolatum composition according to any one of claims 1 to 3. The transmission according to claim 4, characterized in that it is a constant speed joint.