JPH1112589A - Grease composition for constant-velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a plunging type grease composition for a constant-velocity joint, capable of efficiently lubricating the constant-velocity joint, effectively reducing the friction and preventing the generation of the vibration. SOLUTION: This grease composition for a constant-velocity joint comprises (a) a base oil, (b) a urea-based thickener, (c) molybdenum dithiocarbamate, (d) an ester-based synthetic oil, (e) At least one kind of oxidized wax compound chosen from the group consisting of the oxidized wax not containing a metal and an oxidized wax ester not containing the metal, and (f) a sulfur-phosphorus- based extreme-pressure agent not containing the metal, in which the content of sulfur is 10-30%, and that of the phosphorus is 0.5-5%. The components (b), (c), (d), (e) and (f) are preferably included within the range of 1-25 wt.%, 0.1-10 wt.%, 0.5-10 wt.%, 0.5-15 wt.% and 0.1-10 wt.% based on the whole composition respectively.

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 organic molybdenum to urea grease is also used. In the recent automobile industry, in terms of weight reduction and securing of living space, F
The number of vehicles in F rapidly increases, and the constant velocity joint (CVJ), which is indispensable for this, is widely used. In this CVJ,
Plunging type constant velocity joints, especially tripod type constant velocity joints (TJ), perform complicated rolling and sliding motions when rotating at a certain angle, so that rolling resistance occurs in the axial direction, and when starting and accelerating, Of the vehicle body and a beat sound and / or a muffled sound inside the vehicle at a specific speed. In order to solve this problem, various types of constant velocity joints (CVJs) have been improved in their structure. However, it is difficult to improve the joints in terms of space, weight, and cost. 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 a dithiocarbamate, an ester-based synthetic oil, an oxidized wax compound, and a specific sulfur-phosphorus-based extreme-pressure agent is a grease for a conventional constant-velocity joint in an axial force test using an actual constant-velocity joint. In contrast to this, it was confirmed that generation of vibration could be significantly prevented, and the present invention was 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 synthetic oil, (e) metal-free oxidized wax and metal-free oxidized wax ester At least one oxidized wax compound selected from the group consisting of: (f) a sulfur content of 10 to 30;
%, A metal-free sulfur-phosphorus extreme pressure agent having 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. The component (e) used in the present invention includes:
At least one selected from the group consisting of metal-free oxidized waxes and metal-free oxidized wax esters
Although various oxidized wax compounds are used, metal-free oxidized waxes are particularly preferred. Examples of such metal-free oxidized wax include those known as rust inhibitors, for example, ALOX 600 (oxidized wax manufactured by ALOX Corporation), ALOX 800, ALOX 102, and the like. Examples of the metal-free oxidized wax esters include methyl oxide, ethyl ester, propyl ester, isopropyl ester, butyl ester, pentyl ester, and hexyl ester of the above-mentioned oxidized wax, for example, ALOX 350 (ALOX Corporation) known as a rust inhibitor. Oxidized wax esters), ALOX 152, ALOX 162, and the like.

[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, an anticorrosive and the like 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,
(e) an oxidized wax compound: 0.5 to 15% by weight;
(f) Component sulfur-phosphorus extreme pressure agent: 0.1 to 10% by weight.

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) An oxidized wax compound as a component: 1 to 10% by weight, and a sulfur-phosphorus extreme pressure agent as a component (f): 0.5 to 5% by weight. If the content of the component (b) is less than 1% by weight, the thickening effect is reduced and it is difficult to grease, and if the content is more than 25% by weight,
The obtained composition becomes too hard, and it is difficult to obtain the desired effect. The content of the component (c) is less than 0.1% by weight, the content of the component (d) is less than 0.5% by weight, and the content of the component (e) is 0.5.
If the content of component (f) is less than 0.1% by weight,
It is difficult to obtain the desired effect sufficiently, while the content of component (c) is more than 10% by weight, the content of component (d) is more than 10% by weight, and the content of component (e) Is not more than 15% by weight and the content of the component (f) is more than 10% by weight.

[0011]

Next, the present invention will be described with reference to examples and comparative examples. [Examples 1 to 4, Comparative Examples 1 to 6] 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 Example 1 2 3 4 1) Diurea grease 93.5 93.5 92.5 92.5 2) Molybdenum dithiocarbamate 3.0-2.0 2.0 3) Molybdenum dithiocarbamate-3.0 2.0 2.0 4) Ester oil 1.0 1.0 1.0 1.0 5) Oxidation Wax 2.0 2.0 2.0-6) Oxidized wax ester --- 2.0 7) Sulfur-phosphorus extreme pressure agent 0.5 0.5 0.5 0.5 8) Consistency 60w 301 303 300 299 9) Dropping point (℃) 220 225 223 220 10) Shaft Force test -12 -14 -14 -10

[0014]

[Table 2] Table 1 (continued) Comparative Example 1 2 3 4 5 6 ^* 1) Diurea grease 96.0 99.0 98.0 98.0 99.5-2) Molybdenum dithiocarbamate 2.0-----3) Molybdenum dithiocarbamate 2.0---- − 4) Ester oil − 1.0 − − − − 5) Oxidized wax − − 2.0 − − − 6) Oxidized wax ester − − − 2.0 − − 7) Sulfur-phosphorus extreme pressure agent − − − − 0.5 − 8) Butter Degree 60w 301 300 305 297 304 303 9) Dropping point (℃) 219 223 226 223 226 227 227 10) Axial force test -2 +10 +5 +9 +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) Oxidized wax (trade name: ALOX 600 ALOX Corporati
on) 6) Oxidized wax ester (Product name: ALOX 350 ALOX C
orporation) 7) Sulfur-phosphorus extreme pressure agent (trade name: Anglamol 99 manufactured by Lubrizol Japan) * Commercially available grease containing molybdenum dithiocarbamate

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI C10M 129: 68 159: 06 137: 14) C10N 10:12 30:06 40:04

Claims (4)

[Claims] (1) a base oil, (b) a urea thickener,
(c) molybdenum dithiocarbamate, (d) an ester-based synthetic oil, (e) at least one oxidized wax compound selected from the group consisting of a metal-free oxidized wax and a metal-free oxidized wax ester, and (f) A grease composition for constant velocity joints comprising a metal-free sulfur-phosphorus extreme pressure agent having a sulfur content of 10 to 30% and a phosphorus content of 0.5 to 5%. 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. 5 to 10% by weight, the content of the oxidized wax compound is 0.
5 to 15% by weight, the content of sulfur-phosphorus extreme pressure agent is 0.1 to
The grease composition for a constant velocity joint according to claim 1, which is 10% by weight. 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.