JPH10147791A - Grease composition for uniform joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a grease compsn. which efficiently lubricates uniform joints and effectively reduces friction to prevent the occurrence of vibration by compounding a base oil, a urea-base thickener, molybdenum dithiocarbamate, a synthetic ester oil, a Ca salt of an oxidized wax, and an S-P extreme-pressure agent. SOLUTION: This compsn. comprises a base oil (e.g. a mineral oil) pref. in an amt. of 30.0-97.8wt.%, a urea-base thickener (e.g. a diurea compd. obtd. by reacting diphenylmethane 4,4'-diisocyanate with octylamine and stearylamine) pref. in an amt. of 1-25wt.% molybdenum dithiocarbamate pref. in an amt. of 0.1-10wt.%, a synthetic ester oil (pref. at least one oil selected from among di-2-ethylkexyl adipate, sebacate, and phthalate) pref. in an amt. of 0.5-10wt.% a Ca salt of an oxidized was pref. in an amt. of 0.5-15wt.% and an S-P extreme- pressure agent contg. 10-30wt.% S and 0.5-5wt.% P and contg. no metal pref. in an amt. of 0.1-10wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a grease composition for a constant velocity joint. Very high surface pressures are applied to constant velocity joints to be lubricated, and abnormal vibrations often occur because the joints perform complicated rolling movements. Accordingly, the present invention particularly relates to a grease composition for a constant velocity joint capable of efficiently lubricating such a constant velocity joint, effectively reducing friction and preventing generation of vibration.

[0002]

2. Description of the Related Art Conventionally, lubricating greases used in such constant velocity joints include grease using calcium complex soap as a thickening agent, and lithium soap as a thickening agent. There is a grease containing a sulfur-phosphorus extreme pressure agent selected from the group consisting of zyl phosphate and zinc dithiophosphate. Recently, grease obtained by adding molybdenum dithiocarbamate to urea grease has been used.
In the recent automobile industry, FF vehicles are rapidly increasing in terms of weight reduction and securing living space, and constant velocity joints (CVJs), which are indispensable for this, are widely used. This C
Among the VJs, plunging type constant velocity joints, especially tripod type constant velocity joints (TJ), double offset type constant velocity joints (DOJ), etc., have complicated rolling sliding motions at the time of rotation at a certain angle. To do
A sliding resistance is generated in the axial direction, which is a source of vibration during idling, rolling of the vehicle body during starting and acceleration, and beat and / or muffled sound in the vehicle at a specific speed. To solve this problem, various constant velocity joints (C
Although the structure of VJ) itself has been improved, it is difficult to improve the space, weight, and cost occupied by the joint, and grease excellent in vibration reduction performance is required.

[0003]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a grease composition that reduces vibration of a constant velocity joint. It is another object of the present invention to provide a grease composition for a plunging type constant velocity joint which can efficiently lubricate a constant velocity joint, effectively reduce friction and prevent generation of vibration.

[0004]

The present inventors have conducted various studies on the development of grease compositions for reducing friction of constant velocity joints and preventing vibration, and as a result, have found that base oils, urea-based thickeners, molybdenum A grease composition containing dithiocarbamate, an ester-based synthetic oil, and a specific sulfur-phosphorus-based extreme pressure agent is different from a conventional grease for a constant velocity joint in an axial force test using an actual constant velocity joint. It has been confirmed that generation of vibration can be significantly prevented, and the present invention has been completed. The above object of the present invention can be effectively achieved by a grease composition for a constant velocity joint containing the following components. (a) base oil, (b) urea thickener, (c) molybdenum dithiocarbamate, (d) ester-based synthetic oil, (e) calcium salt of oxidized wax, and (f) sulfur content is 10 to 10.
A metal-free sulfur-phosphorus extreme pressure agent containing 30% and a phosphorus content of 0.5 to 5%.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As the base oil of the component (a) used in the present invention, commonly used lubricating oils such as mineral oils, ether-based synthetic oils and hydrocarbon-based synthetic oils, or mixed oils thereof are used. But are not limited to these.
Examples of the urea-based thickener of the component (b) used in the present invention include, but are not limited to, diurea compounds and polyurea compounds. The diurea compound is obtained, for example, by reacting a diisocyanate with a monoamine. Examples of the diisocyanate include phenylene diisocyanate, diphenyl diisocyanate, phenyl diisocyanate, diphenylmethane diisocyanate, octadecane diisocyanate, decane diisocyanate, and hexane diisocyanate.
Examples of the monoamine include octylamine, dodecylamine, hexadecylamine, octadecylamine, oleylamine, aniline, p-toluidine, cyclohexylamine and the like.

The polyurea compound is obtained, for example, by reacting a diisocyanate with a diamine. Examples of the diisocyanate include those similar to those used for producing a diurea compound, and examples of the diamine include ethylenediamine, propanediamine, butanediamine, hexanediamine, octanediamine, phenylenediamine, tolylenediamine, and xylenediamine. Can be A particularly preferred urea thickener is a diurea compound obtained by reacting an aliphatic amine such as octylamine or stearylamine, or a mixture thereof with a diisocyanate compound.

Preferred examples of molybdenum dithiocarbamate as the component (c) used in the present invention include those represented by the following formula (1). (R ¹ R ² N-CS-S) ₂ -Mo ₂ OmSn (wherein R ¹ and R ² independently represent an alkyl group having 1 to 24 carbon atoms, preferably 3 to 18 carbon atoms, and m is 0 ~ 3, n
Is 4 to 1 and m + n = 4. Examples of the ester-based synthetic oil (d) used in the present invention include di-2-ethylhexyl adipate, di-2-ethylhexyl sebacate and diphthalate, which are known as rubber plasticizers and lubricating oils. -2-ethylhexyl. Of these, di-2-ethylhexyl adipate is particularly preferred. Examples of the calcium salt of the oxidized wax of the component (e) used in the present invention include those known as rust inhibitors.

[0008] The sulfur-phosphorus extreme pressure agent of component (f) used in the present invention has excellent sulfur content by adjusting the sulfur content to 10 to 30% and the phosphorus content to 0.5 to 5%. It is possible to exhibit abrasion prevention performance and seizure prevention performance. If the sulfur component is more than the above range, the joint is likely to corrode, and if the phosphorus component is more than the above range, the effect of preventing the joint from being worn cannot be obtained. If both are less than the above ranges, it will be difficult to sufficiently exhibit the wear prevention performance and the seizure prevention performance.

The grease composition for a constant velocity joint of the present invention can contain an antioxidant, a rust inhibitor and an anticorrosive in addition to the above components. The grease composition for a constant velocity joint of the present invention is preferably a base oil of the component (a): 30.0 to 97.8% by weight, based on the total weight of the grease composition.
(b) Component urea thickener: 1 to 25% by weight, (c)
Component molybdenum dithiocarbamate: 0.1 to 10% by weight, component (d) ester-based synthetic oil: 0.5 to 10% by weight,
It contains 0.5 to 15% by weight of a calcium salt of an oxidized wax as the component (e), and 0.1 to 10% by weight of a sulfur-phosphorus extreme pressure agent as the component (f).

The grease composition for a constant velocity joint of the present invention is more preferably 55.0 to 94.0% by weight of the base oil of the component (a), and (b) based on the total weight of the grease composition. Component urea thickener: 3 to 20% by weight, component (c) molybdenum dithiocarbamate: 0.5 to 5% by weight, component (d) ester synthetic oil: 1 to 5% by weight, (e) Calcium salt of oxidized wax as a component: 1 to 10% by weight, and sulfur-phosphorus extreme pressure agent as a component (f): 0.5 to 5% by weight.
When the content of the component (b) is less than 1% by weight, the thickening effect is reduced and the grease is hardly formed. When the content is more than 25% by weight, the obtained composition becomes too hard, and the desired effect is obtained. It becomes difficult. The content of component (c) is less than 0.1% by weight, the content of component (d) is less than 0.5% by weight, the content of component (e) is less than 0.5% by weight, the content of component (f) Content is 0.1% by weight
Below, it is difficult to achieve the desired effect sufficiently,
On the other hand, the content of the component (c) is more than 10% by weight, the content of the component (d) is more than 10% by weight, and the content of the component (e) is 1%.
When the content is more than 5% by weight and the content of the component (f) is more than 10% by weight, the effect is not increased.

[0011]

Next, the present invention will be described with reference to examples and comparative examples. [Examples 1 to 5, Comparative Examples 1 to 4] 431.8 g of base oil in a container
And diphenylmethane-4,4'-diisocyanate 52.
Take 3 g and heat the mixture to 70-80 ° C. In a separate container, 431.7 g of base oil, 27.0 g of octylamine, and 57.2 g of stearylamine were heated, heated to 70 to 80 ° C., added to the previous container, and reacted for 30 minutes while stirring well. Thereafter, with stirring, the temperature was raised to 160 ° C., and the mixture was allowed to cool to obtain a base urea grease. Table 1 shows the base grease.
In the formulation shown in Table 2, additives were added, base oil was added as appropriate, and the resulting mixture was passed through a three-roll mill to obtain a consistency No. 1.5.
Adjusted to grade.

Kind of base oil Mineral oil Viscosity 40 ° C. 123 mm ² / s 100 ° C. 13.4 mm ² / s Viscosity index 103 The physical properties of these greases were evaluated by the test methods described below, and the obtained results were shown in Table 1. Also described in 1. <Consistency> According to JIS K 2220 5.3 <Drop point> According to JIS K 2220 5.4 <Axial force test> An axial force test was performed on an actual joint under the following conditions to measure the axial force. Test conditions Rotation speed 150 rpm Torque 300 N-m Joint angle 12 ° Operating time 8 minutes Joint type tripod joint Measurement item The joint axial force was measured and evaluated by the rate of change based on a commercially available urea grease.

[0013]

[Table 1] Table 1 Examples 1 2 3 4 5 1) Diurea grease 93.5 93.5 92.5 92.5 92.5 2) Molybdenum dithiocarbamate 3.0-2.0 2.0 2.0 3) Molybdenum dithiocarbamate-3.0 2.0 2.0 2.0 4) Ester oil 1.0 1.0 1.0 − − 5) Ester oil − − − 1.0 − 6) Ester oil − − − − 1.0 7) Oxidized wax calcium salt 2.0 2.0 2.0 2.0 2.0 8) Sulfur-phosphorus extreme pressure agent 0.5 0.5 0.5 0.5 0.5 9) Consistency 60w 303 298 300 299 306 10) Dropping point (℃) 223 222 218 220 224 11) Axial force test -13 -12 -15 -9 -10

[0014]

[Table 2] (Continued)Comparative example 1 2 3 4 5 * 1) Diurea grease 96.0 99.0 98.0 99.5 2) Molybdenum dithiocarbamate 2.0---3) Molybdenum dithiocarbamate 2.0---4) Ester oil-1.0--5) Ester oil----6) Ester oil---- 7) Oxidized wax calcium salt − − 2.0 − 8) Sulfur-phosphorus extreme pressure agent---0.5  9) Consistency 60w 301 300 299 304 303 10) Dropping point (℃) 219 223 220 226 227 11) Axial force test -2 +10 +8 +12 standard

1) Diurea grease using a diurea compound in which octylamine and stearylamine are mixed and used as a monoamine. 2) Molybdenum dithiocarbamate (trade name: Molyvan)
A RTVanderbilt) 3) Molybdenum dithiocarbamate (trade name: Molyvan
822 RTVanderbilt) 4) Di-2-ethylhexyl adipate (trade name: Sansosizer DOA Shin Nihon Rika) 5) Di-2-ethylhexyl sebacate (trade name: Sansociser DOS Shin Nihon Rika) 6 ) Di-2-ethylhexyl phthalate (trade name: SANSOSIZER DOP manufactured by Shin Nihon Rika Co., Ltd.) 7) Calcium salt of oxidized wax (trade name: ALOX 165 ALO)
X Corporation) 8) Sulfur-phosphorus extreme pressure agent (trade name: Mobilad G-305 Mobil Chemical Co.) (or brand name: Lubrizol 810 Nippon Lubrizol) * Commercially available grease containing molybdenum dithiocarbamate

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10M 129: 56) C10N 10:04 10:12 30:06 40:04 50:10

Claims (4)

[Claims] (1) a base oil, (b) a urea thickener,
(c) molybdenum dithiocarbamate, (d) ester-based synthetic oil, (e) calcium salt of oxidized wax, and (f) a sulfur content of 10 to 30% and a phosphorus content of 0.5 to 5%. A grease composition for constant velocity joints comprising a sulfur-phosphorus extreme pressure agent containing no metal. 2. The total composition has a urea thickener content of 1 to 25% by weight, a molybdenum dithiocarbamate content of 0.1 to 10% by weight, and an ester synthetic oil content of 0.1% by weight. 2. The composition according to claim 1, wherein the content of calcium salt of the oxidized wax is 0.5 to 15% by weight, and the content of the sulfur-phosphorus extreme pressure agent is 0.1 to 10% by weight. Grease composition for speed joints. 3. The synthetic ester-based oil according to claim 1, wherein the adipate is di-2-adipate.
Ethylhexyl, di-2-ethylhexyl sebacate,
The grease composition for a constant velocity joint according to claim 1, wherein the grease composition is at least one selected from the group consisting of: and di-2-ethylhexyl phthalate. 4. The synthetic ester-based oil according to claim 1, wherein the di-2-adipate is
Ethylhexyl, di-2-ethylhexyl sebacate,
The grease composition for a constant velocity joint according to claim 2, wherein the grease composition is at least one selected from the group consisting of: and di-2-ethylhexyl phthalate.