KR0147700B1 - Extreme pressure and low friction properties grease composition - Google Patents

Abstract

Lithium metal soap containing boric acid as a thickener in base oil is used, and molybdenum dithiocarbamate (Mo-DTC) is mixed as extreme pressure and anti-wear agent, and antimony dithiocarbamate (Sb-DTC) is mixed as extreme pressure and antioxidant. The present invention relates to a grease composition having extreme pressure and low friction, by adding zinc dithiophosphate (Zn-DTP), which is an anti-wearing agent and a low-friction imparting agent, to a small amount of molybdenum disulfide (MoS2) having antifreeze corrosion resistance.

Description

Compositions with extreme pressure and low friction

FIG. 1 is a graph showing the results of comparing the axial force test for each load torque of a grease composition according to the present invention and a conventional commercial grease.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to greases having extreme pressure and low friction, and in particular, molybdenum dithiocarbamate (hereinafter referred to as Mo-DTC), which gives extreme pressure and wear resistance to base oils, and antimony, which has good oxidation resistance. Lithium metal soap containing boric acid with excellent heat resistance as a thickener to ordinary extreme pressure grease compositions composed of Sb-Dithiocarbamate (hereinafter referred to as Sb-DTC) and zinc dithiophosphate which imparts wear resistance and low friction ( Zn-Dithiophosphate (hereinafter referred to as Zn-DTP) and an uncorrosive anticorrosion agent, the present invention relates to a grease composition which greatly improves extreme pressure, abrasion resistance, and low friction caused by mixing molybdenum disulfide (MoS ₂ ).

Until now, extreme pressure additives composed of phosphorus, sulfur, and molybdenum disulfide in areas requiring extreme pressure and low friction, such as constant velocity joints of cars, ball joints, propella shafts, and gears of industrial machines These greases have been mainly used, and such greases have problems such as a severe frictional resistance due to poor lubrication due to deterioration of lubrication conditions due to the development of industrial machines, miniaturization and lightening of automobiles.

In particular, the constant velocity joints for automobiles are used as a combination of fixed joints mounted on the wheel side and plunging joints applied to the deflation side, and the fixed joints are ball joints. In the circular groove of the inner ring, the ball makes rolling movement while making a large angle with high torque transmission, and the cage makes sliding, which reduces the durability of the joint by friction resistance between each component. It has been a factor.

The plunging joint has a function of absorbing the axial displacement of the joint center according to the displacement of the vehicle under high torque and inflation, but the defect that the axial force is generated by the rolling and sliding frictional resistance due to the axial movement there was.

In general, the tripod joint, a representative form of the plunging joint, has three axial forces per rotation of the joint due to the sliding and rolling motion of a spherical roller that moves axially at an arbitrary angle on three housing driving surfaces equal to 120 °. This happens.

As such, the axial force generated in the plunging joint is generated as the joint angle and the transmission torque become larger, and when it coincides with the natural frequency of the engine and the body suspension, it causes resonance and causes vibration and noise of the vehicle body, which causes the ride comfort. In order to prevent vibration and noise while improving durability by improving the defects of the constant velocity joint, it is strongly proposed in accordance with the trend of advanced vehicles.

Therefore, there is a need for a grease having a low friction which is very effective for improving the durability of the joint, reducing vibration, noise and axial force.

Therefore, the present invention is composed of conventional base oils, thickeners and molybdenum dithiocarbamate (Mo-DTC) and antimony dithiocarbamate (Sb-DTC) and excellent in extreme pressure and abrasion resistance and oxidation resistance, but less lubrication, friction resistance Molybdenum dithiocarbamate, an extreme pressure agent with excellent base oil and abrasion resistance, to improve defects with severe friction resistance due to severe and weak anti-corrosive resistance, base oil, thickener and phosphorus, sulfur and molybdenum disulfide. Lithium metal soap containing boric acid having excellent heat resistance as a thickener, and abrasion resistance and low frictional force in a common extreme pressure grease composition composed of (Mo-DTC) and antimony dithiocarbamate (Sb-DTC), an extreme pressure additive having good oxidation stability. a mixture of the zinc dithio phosphate (Zn-DTP) and the fine movement inhibitor of molybdenum disulfide (MoS ₂₎ for imparting extreme pressure wear resistance Antioxidant castle as well as to provide low friction and kojeo fine corrosion resistance and grease composition excellent in heat resistance, when it contains a silye described in detail as follows.

As the base oil used in the present invention, all greases using mineral oil, synthetic oil, or mixed oil, which are commonly used, may be used. The viscosity thereof is about 15 cSt at a temperature of 100 ° C, and boric acid is used as a thickener in lithium soap. It is characterized in that the addition of boric acid is because the dropping point is higher than the conventional lithium soap by 30 ° C is higher than the conventional lithium soap, thus giving the advantage of superior heat resistance than conventional lithium soap.

In this case, the content of the thickener is preferably 3-18% by weight of the total grease composition. If the content is less than 3% by weight, the grease is too thin and the water resistance is poor. Too hard, there is a problem in that it is difficult to refuel and generates a lot of residue.

The content of boric acid is preferably 0.1-0.5% by weight with respect to the total thickener, if the content is less than 0.1% by weight there is no heat-resistant effect, if it exceeds 0.5% by weight is difficult to manufacture grease and the effect is the same problem.

Molybdenum dithiocarbamate (Mo-DTC), a well-known organic molybdenum compound as the extreme pressure and abrasion resistant agent used in the present invention, also plays a role of friction alleviation in addition to the extreme pressure and abrasion resistance. Since it is the same or worse, it is preferable to add 1-10% by weight, more preferably 3-5% by weight, and also antimony dithiocarbamate (Sb-DTC) which is a conventional extreme pressure additive and an antioxidant In the present invention, it is preferable to add 5% by weight or less, and the effect becomes the same even when adding more, and zinc dithiophosphate (Zn-DTP) which gives abrasion resistance and low friction which is a characteristic of the present invention is 5 It is good to add less than or equal to 1% by weight, and even if it is added to less than or equal to 1 weight, there is a sufficient effect. For molybdenum disulfide (MoS ₂ ) to be represented, it is appropriate to add 2-5% by weight, and preferably 3% by weight.

In addition to the above additives, copper corrosion inhibitors and antirust additives may be used.

In the present invention constituted as described above, a mixture of molybdenum dithiocarbamate (Mo-DTC), a metal complex compound that plays a role of friction relaxation while being an extreme pressure and anti-wear agent, and antimony dithiocarbamate (Sb-DTC), an extreme pressure and an antioxidant, In conventional grease, proper use of Lithum metal soap containing boric acid, a heat-resistant thickener, zinc dithiophosphate (Zn-DTP) that imparts abrasion resistance and low friction, and molybdenum disulfide (MoS ₂ ) having excellent antifreeze corrosion resistance It has excellent abrasion resistance and extreme pressure that could not be seen, as well as excellent low friction and anti-corrosive corrosion resistance, and excellent heat resistance. When applying this grease to the constant velocity joint, the axial force is significantly reduced and there is no flaking and no slide. The resistance is reduced, which has the advantage of suppressing abnormal sounds and vibrations.

In order to confirm the performance of the composition of the present invention, the composition of the present invention was prepared as in Examples 1 and 2 and subjected to a performance verification test in comparison with a conventional grease.

Example 1

22.2 kg of paraffinic mineral oil having a viscosity of 15 cSt and a viscosity index of 99 at 100 ° C. in a 100 kg experimental reactor was dissolved in 5.4 kg of 12 hydroxy stearic acid, followed by heating and dissolving lithium hydroxide (LiOH). 0.756 kg and 13.5 g of boric acid (Boric Acid) were added to the reactor in an aqueous solution of 15% by weight, and then the mixture was dehydrated while heating and stirring with a silicone oil having excellent thermal stability as a heat medium.

When the temperature of the mixture rises to about 135 ° C in the reactor, it is kept at this temperature for more than 20 minutes for complete reaction and dehydration, and then the temperature of the mixture is raised to 201 ° C while stirring with the addition of 22.2 kg of base oil.

Hold at this temperature for about 10 minutes, then add the remaining 22.2 kg of base oil and cool the mixture while stirring.

When the temperature of the mixture is cooled to about 100 ° C., 3 wt% molybdenum dithiocarbamate (Mo-DTC), 0.5 wt% zinc dithiophosphate (Zn-DTP), and antimony dithiocarbamate (Sb-DTC) 3 Wt%, 2.5-dimercapto-1, 3, 4-thiadia sol derivatives, copper corrosion inhibitors, and 50% neutral barium dinonylsulfonate 1.5% by weight of anti-rust additives were added, respectively. ) Was homogenized.

The same method as in Example 1 was carried out, but 3 wt% molybdenum disulfide (MoS2) was added.

Table 1 shows the important properties of Examples 1 and 2 of the present invention and the conventional commercial grease.

[Confirmation Experiment 1]

The samples of Table 1 were subjected to the glomerular pressure test of the load resistance test and the glomerular wear test of the abrasion resistance test.

The quadripolar pressure test was conducted at 1770 ± 60rpm, time 10 seconds, and sample temperature 27 ± 8˚C according to ASTM D2596 test method.The sandblast test was performed at 1200 ± 50rpm, time 60 minutes, temperature according to ASTM D2266 test method. The experiment was conducted at 75 ± 1.7˚C and 40 ± 0.2kg load, and the results are shown in Table 2.

[Confirmation experiment 2]

Samples in Table 1 were filled in a constant velocity joint, and the endurance test was carried out in the constant velocity joint endurance tester according to the prescribed conditions, and the peeling phenomenon of the internal parts of the joint was checked for damage.

The experimental results are shown in Table 3.

[Test 3]

The sample shown in Table 1 was filled in the tripod joint which is a plunging joint, and the axial force test was performed.

In the axial force test, the treeport joint was first tamed at 600rpm at 7.5 ° operating angle for 1 hour, and then measured at 200rpm for 30 minutes for 3 minutes and the average value was displayed. The result was measured for each load torque. As shown.

Claims (2)

Lithium soap containing boric acid as a thickener in base oil, molybdenum dithiocarbamate (Mo-DTC), a common extreme pressure and anti-wear agent, and antimony dithiocarbamate (Sb-DTC), a common extreme pressure and antioxidant A grease composition having extreme pressure and low friction, characterized by mixing zinc dithiophosphate (Zn-DTP) and molybdenum disulfide (MoS ₂ ), which is an antifreeze corrosion inhibitor, for imparting wear resistance and low friction. The thickener is 3-18% by weight of the total grease composition, the boric acid is 0.1-0.5% by weight relative to the thickener, molybdenum dithiocarbamate (Mo-DTC) 1-10% by weight, zinc dithiophosphate ( Zn-DTP) is less than 5% by weight, antimony dithiocarbamate (Sb-DTC) is less than 5% by weight, molybdenum disulfide (MoS ₂ ) is characterized by using 2-5% by weight of extreme pressure and low friction Having a grease composition.