JP5113807B2 - Grease composition for constant velocity joints - Google Patents

Description

  The present invention relates to a grease composition that is adapted to a lubricating part of a constant velocity joint of an automobile.

  Constant velocity joints (hereinafter abbreviated as CVJ) are members that transmit the power of the engine to the tires evenly and rotate the left and right wheels at a constant speed. This CVJ has grown rapidly on the wave of FF in automobiles. When the tripart joint (TJ) and the double offset joint (DOJ) slide while transmitting torque, a sliding resistance is generated in the axial direction. If this resistance is large, vibrations from the engine and the road surface are transmitted to the vehicle body, which becomes a vibration source of the vehicle body and noise in the vehicle. In order to solve this problem, mechanical measures for CVJ itself have been taken, but the use of low friction grease reduces the frictional resistance of CVJ and is effective in preventing vehicle vibration and noise.

  Therefore, especially the grease filled in the plunging type constant velocity joint is strongly required to reduce the frictional resistance of the sliding portion. Grease having a low friction coefficient can reduce the friction of CVJ and prevent the occurrence of vibration.

  In order to cope with such problems, there are increasing examples of using urea grease having excellent heat resistance and friction characteristics in the market. As typical prior art, there are Patent Document 1 and Patent Document 2.

  The technology of Patent Document 1 is a grease composition for constant velocity joints in which (a) molybdenum disulfide (b) molybdenum dialkyldithiocarbamate disulfide and (c) lead dialkyldithiocarbamate are blended with urea grease.

  The technology of Patent Document 2 discloses a grease for a constant velocity joint obtained by using molybdenum dithiocarbamate and molybdenum dithiophosphate in combination with urea grease, or mixing zinc dithiophosphate with these organic molybdenum compounds. Yes.

  However, the greases in these prior arts have a low frictional force grease that is sufficiently satisfactory because the induced thrust force of the plunging type constant velocity joint is small compared to the case of filling with commercially available grease, but the shaft vibrates. I could not say it.

JP-A-6-57283 Japanese Patent Publication No. 5-79280

  An object of the present invention is to provide a grease composition for a constant velocity joint having a low coefficient of friction that reduces vibration of CVJ.

  As a result of intensive studies to further improve the technique of Patent Document 2 (Japanese Patent Publication No. 5-79280), the present inventors have suppressed vibration of CVJ by combining a specific sulfur compound with the conventional technique. In other words, it has been found that a grease having a lower coefficient of friction can be obtained, and the present invention has been completed.

（式中、Ｒ^１は一級または二級のアルキル基およびアリール基よりなる群から選ばれた基である。）
で示されるモリブデンジアルキルジチオフォスフェートまたはモリブデンジアリールジチオフォスフェートの少なくとも１種および、
（Ｃ）無灰ジチオカーバメート、または、無灰ジチオカーバメートとジンクジチオカーバメートの混合物、を
（Ａ）、（Ｂ）、および（Ｃ）のそれぞれの配合量が全量に対して０．１〜１０重量％となるよう混合したことを特徴とする等速ジョイント用グリース組成物に関する。 The present invention is a grease composed of a base oil and a thickener of a diurea compound.
(A) molybdenum dialkyldithiocarbamate and (B) the following general formula (I)

(Wherein R ¹ is a group selected from the group consisting of a primary or secondary alkyl group and an aryl group.)
At least one of molybdenum dialkyldithiophosphate or molybdenum diaryldithiophosphate represented by
(C) ashless dithiocarbamate or a 0.1 mixture of ashless dithiocarbamate and zinc dithiocarbamate Mae bets, the (A), the respective amount of (B), and (C) of the total amount The present invention relates to a grease composition for a constant velocity joint which is mixed so as to be 10% by weight.

  As the base oil that can be used in the present invention, mineral oils and synthetic oils such as ester oils, ether oils, hydrocarbon oils or mixtures thereof can be used.

As a thickener, a diurea compound is used.

  If the content of each of the greases (A), (B), and (C) is too large, the effect is the same or worsens, so the content is 10% by weight or less. (A) and (B) are preferably 3 to 5% by weight or less, but (C) is most preferably around 1% by weight. However, it is preferable to use at least 0.1% by weight of any of (A), (B), and (C).

  Further, in addition to these additives, any additive such as an antioxidant, a rust inhibitor, and a dispersing agent may be used in combination as appropriate so as not to hinder the present invention.

  Specific examples of the component (A) molybdenum dialkyldithiocarbamate include molybdenum sulfide diethyldithiocarbamate, molybdenum dipropyldithiocarbamate, molybdenum dibutyldithiocarbamate, molybdenum dipentyldithiocarbamate, molybdenum dipentyldithiocarbamate, molybdenum dihexyldithiocarbamate, and molybdenum dioctyldithiosulfide. Carbamate, molybdenum didecyl dithiocarbamate, molybdenum didodecyl dithiocarbamate, molybdenum di (butylphenyl) dithiocarbamate, molybdenum di (nonylphenyl) dithiocarbamate, sulfurized oxymolybdenum diethyldithiocarbamate, sulfurized oxymolybdenum dipropyldithiocarbamate, sulfurized oxymolybdenum dibutyl Dithiocarba , Sulfurized oxymolybdenum dipentyldithiocarbamate, sulfurized oxymolybdenum dihexyldithiocarbamate, sulfurized oxymolybdenum dioctyldithiocarbamate, sulfurized oxymolybdenum didecyldithiocarbamate, sulfurized oxymolybdenum didodecyldithiocarbamate, sulfurized oxymolybdenum di (butylphenyl) dithiocarbamate, sulfurized oxymolybdenum disulfide (Nonylphenyl) dithiocarbamate and mixtures thereof can be mentioned.

Specific examples of R ¹ in the formula (I) of the component (B) include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, Dodecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosyl group, docosyl group, tetracosyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, ethylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, phenyl group, tolyl group, xylyl Group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, decylphenyl group, dodecylphenyl group, tetradecylphenyl group, hexadecylphenyl group Group, octadecylphenyl group, benzyl group, phenethyl group and the like. Each R ¹ in the formula may be the same or different.

  Specific examples of the component (B) include, for example, molybdenum sulfide diethyldithiophosphate, molybdenum dipropyldithiodisulfate, molybdenum dibutyldithiophosphate, molybdenum dipentyldithiophosphate, molybdenum dihexyldithiophosphate, molybdenum sulfide. Dioctyl dithiophosphate, molybdenum sulfide didecyl dithiophosphate, molybdenum sulfide didodecyl dithiophosphate, molybdenum di (butylphenyl) dithiophosphate, molybdenum di (nonylphenyl) dithiophosphate, oxymolybdenum diethyldithiophosphate, oxymolybdenum disulfide Propyl dithiophosphate, sulfurized oxymolybdenum dibutyldithiophosphate, Oxymolybdenum dipentyldithiophosphate, sulfurized oxymolybdenum dihexyldithiophosphate, sulfurized oxymolybdenum dioctyldithiophosphate, sulfurized oxymolybdenum didecyldithiophosphate, sulfurized oxymolybdenum didodecyldithiophosphate, sulfurized oxymolybdenum di (butylphenyl) dithiophosphate And sulfurized oxymolybdenum di (nonylphenyl) dithiophosphate.

  The grease of the present invention is used for a constant velocity joint having a lower friction coefficient than the technology of the conventional patent document 2 (Japanese Patent Publication No. 5-79280) by using together an additive containing a limited sulfur compound. In particular, a grease composition suitable for plunging type constant velocity joints could be provided.

  Although an example and a comparative example explain the present invention, the present invention is not limited at all by this.

  Examples and Comparative Examples shown in Tables 1 and 2 show that the base greases described below include, as additives, at least one of molybdenum dithiocarbamate and molybdenum dialkyldithiophosphate or molybdenum diaryldithiophosphate and ashless dithiocarbamate or zinc dithiol. After adding a sulfur compound selected from a mixture with carbamate, it is uniformly finished with three rolls.

  The base grease used in the examples and comparative examples will be described below.

I. Diurea grease In a mineral oil (5400 g) with a kinematic viscosity at 100 ° C. of about 15 mm ² / s, 1 mol of 4,4′-diphenylmethane diisocyanate (295.1 g) is reacted with 2 mol of octylamine (304.9 g). The resulting urea compound was uniformly dispersed and treated to obtain a grease having a consistency (25 ° C., 60 W): 283 and a dropping point: 265 ° C. This grease is prepared by adjusting the urea compound content to 10% by weight.

II. Tetraurea grease In mineral oil (5220 g) with a kinematic viscosity at 100 ° C. of about 15 mm ² / s, 2 moles of 4,4′-diphenylmethane diisocyanate (446.05 g) and 1 mole of octylamine (115.26 g), 1 Mole of laurylamine (165.13 g) and 1 mol of ethylenediamine (53.56 g) were reacted, and the resulting urea compound was uniformly dispersed and treated to achieve a consistency (25 ° C., 60 W): 325, dropping point: A grease of 253 ° C. was obtained. This grease is prepared by adjusting the urea compound content to 13% by weight.

III. Lithium soap grease In a mineral oil (5400 g) having a kinematic viscosity at 100 ° C. of about 11 mm ² / s, lithium 12-hydroxystearate (600 g) is dissolved as lithium soap, uniformly dispersed and treated, and a consistency (25 (C, 60 W): 271, a grease having a dropping point of 198 ° C. was obtained. This grease has a lithium soap content adjusted to 10% by weight.

IV. Aluminum complex soap grease Dissolve benzoic acid (26.37 g) and stearic acid (55.80 g) in mineral oil (712 g) with a kinematic viscosity at 100 ° C. of about 11 mm ² / s, and then commercially available cyclic aluminum oxide isopi 48.94 g of a rate lubricant (trade name: Algomer manufactured by Kawaken Fine Chemical Co., Ltd.) is added and reacted, and the resulting soap is uniformly dispersed and treated to achieve consistency (25 ° C., 60 W): 272, drops Point: A grease of> 270 ° C. was obtained. This grease has a lithium soap content adjusted to 11% by weight. The molar ratio of benzoic acid (BA) and stearic acid (FA)
BA / FA = 1.1
And the molar ratio of aluminum (Al) to benzoic acid (BA) and stearic acid (FA):
(BA + FA) /Al=1.9
It is what.

  The grease compositions of Examples and Comparative Examples whose compositions are shown in Tables 1 and 2 were subjected to a Falex test under the following conditions, and the friction coefficient was measured (IP241 / 69). The test time was 15 minutes, and the friction coefficient at the end (after 15 minutes) was determined. The results are also shown in Tables 1-2.

Test conditions Rotational speed: 290 r. p. m
Load: 200 lb
Temperature: Room temperature Time: 15 minutes Grease: About 1g of grease is applied to the test piece

[Note] in the following Tables 1 and 2 are as shown in 1) to 5) in the table.
1) Vanderbilt product name Moriban A
2) Asahi Denka Kogyo Co., Ltd. Product name Sakura Lube 300
3) Vanderbilt product name Moriban L
4) Vanderbilt brand name Van Lube 7723
5) Vanderbilt company name Van Lube 869

Claims (1)

To grease composed of base oil and diurea compound thickener,
(A) molybdenum dialkyldithiocarbamate and (B) the following general formula (I)

(Wherein R ¹ is a group selected from the group consisting of a primary or secondary alkyl group and an aryl group.)
At least one of molybdenum dialkyldithiophosphate or molybdenum diaryldithiophosphate represented by
(C) ashless dithiocarbamate or a 0.1 mixture of ashless dithiocarbamate and zinc dithiocarbamate Mae bets, the (A), the respective amount of (B), and (C) of the total amount A grease composition for a constant velocity joint, wherein the grease composition is mixed so as to be 10% by weight.