Dinuclear molybdenum complex and use of same in lubricating compositions

Abstract

The present invention relates to a dinuclear molybdenum complex with ligands selected from fatty tertiary amines of formula (I):
R—N[(CH.sub.2).sub.nR.sup.2][(CH.sub.2).sub.nR.sup.3]  (I)
wherein R represents a linear or branched alkyl comprising 3 to 30 carbon atoms, preferably 3 to 20, advantageously 7 to 17 carbon atoms; n, identical or different, represents 2 or 3; R.sup.2 and R.sup.3, identical or different, represent an O, OR, NR′.sub.2, COOR′, or COO group, where R′, identical or different, represents a hydrogen atom or an alkaline or alkaline earth metal, preferably R′ is H, preferably R.sup.2 and R.sup.3, identical or different, represent an OH or NH.sub.2 group.

Claims

1. A molybdenum dinuclear complex with ligands selected from fatty tertiary amines having the formula (I):
R—N[(CH.sub.2).sub.nR.sup.2][(CH.sub.2).sub.nR.sup.3]  (I) in which: R represents an alkyl, either linear or branched, comprising from 3 to 30 carbon atoms; n, being identical or different, represents 2 or 3; R.sup.2 and R.sup.3, being identical or different, represent a group: O, OR, NR′.sub.2, COOR′, or COO, where R′, being identical or different, represents a hydrogen atom or an alkali metal, or an alkaline earth metal.

2. The complex according to claim 1, in which the compound having the formula (I) is selected from the following compounds: ##STR00011## R being as defined in claim 1.

3. The complex according to claim 1 that corresponds to the formula (II): ##STR00012## in which R and n are as defined above and each of the (multiple) X, being identical or different, represents O, OR, NR′.sub.2, COOR′, or COO, where R′, being identical or different, represents a hydrogen atom or an alkali metal or an alkaline earth metal.

4. The molybdenum complex preparation method for preparing a complex according to claim 1 comprising the mixing of a molybdenum compound and a compound having the formula (I).

5. A lubricating composition comprising: at least one base oil; at least one dinuclear molybdenum complex according to claim 1.

6. The lubricating composition according to claim 5 that further comprises at least one anti-wear additive.

7. A lubricating composition according to claim 5 comprising from 0.001 to 0.1% by weight of the dinuclear molybdenum complex, relative to the total weight of the composition.

8. A method for lowering the coefficient of friction of a lubricating composition, the method including lowering the coefficient of friction with a complex according to claim 1 in the lubricating composition which further comprises at least one base oil.

9. A method for stabilizing the molybdenum in a lubricating composition, the method comprising the use of a compound having the formula (I)
R—N[(CH.sub.2).sub.nR.sup.2][(CH.sub.2).sub.nR.sup.3]  (I) in which: R represents an alkyl, either linear or branched, comprising from 3 to 30 carbon atoms; n, being identical or different, represents 2 or 3; R.sup.2 and R.sup.3, being identical or different, represent a group: O, OR, NR′.sub.2, COOR′, or COO, where R′, being identical or different, represents a hydrogen atom or an alkali metal, or an alkaline earth metal.

10. A lubrication method for lubricating an engine, the method including the lubrication of component parts of the engine with the composition according to claim 5.

11. A molybdenum protection method, for protecting the molybdenum in a lubricating composition comprising at least one base oil, from degradation, the method comprising of the complexation of the molybdenum in the form of a dinuclear complex with at least one compound having the formula (I):
R—N[(CH.sub.2).sub.nR.sup.2][(CH.sub.2).sub.nR.sup.3]  (I) in which: R represents an alkyl, either linear or branched, comprising from 3 to 30 carbon atoms; n, being identical or different, represents 2 or 3; R.sup.2 and R.sup.3, being identical or different, represent a group: O, OR, NR′.sub.2, COOR′, or COO, where R′, being identical or different, represents a hydrogen atom or an alkali metal, or an alkaline earth metal.

12. A Fuel Eco enhancing method for enhancing the Fuel Eco properties of a lubricating composition comprising at least one base oil, the method comprising of the addition, in the said lubricating composition, of a dinuclear complex according to claim 1.

13. The method according to claim 12, wherein the dinuclear molybdenum complex is used in an amount ranging from 100 ppm to 1000 ppm molybdenum, by weight relative to the total weight of the lubricating composition.

14. The complex according to claim 1, wherein R represents an alkyl, either linear or branched, comprising from 3 to 20 carbon atoms.

15. The complex according to claim 1, wherein R represents an alkyl, either linear or branched, comprising from 7 to 17 carbon atoms.

16. The complex according to claim 1, wherein R.sup.2 and R.sup.3 which are identical or different, represent an OH or NH.sub.2 group.

17. The method according to claim 8, for maintaining a low coefficient fraction over time.

18. The method according to claim 12, wherein the dinuclear molybdenum complex is used in an amount ranging from 400 ppm to 800 ppm molybdenum.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1 provides the molbdenum content for compositions according to the invention and for comparative compositions after 1 month.

DETAILED DESCRIPTION

(2) The present application will be described here below with the aid of non-limiting examples.

Example 1: Preparation of Dinuclear Molybdenum Complexes

(3) The dinuclear molybdenum complexes are obtained by mixing MoO3 with the following amines at ambient temperature for a period of 2 weeks. The weight of amine used in implementation is equal to 3×(0.5/n) %, with n corresponding to the number of nitrogen in the molecule.

(4) TABLE-US-00002 TABLE 2 Example 1.1 (comparative) Duomeen CD (N-Coco-1,3-diaminopropane. N-cocoalkyl-1,3-diaminopropane) Example 1.2 (comparative) Triameen T (N-tallow alkyldipropylene triamine) Example 1.3 (invention) Stearyldiethanolamine Example 1.4 (invention) Triameen YT (N tallow alkyl dipropylene branched triamine)

(5) The lubricating compositions are then produced from each of the complexes obtained by mixing a base oil of the type Poly-alpha-olefin (PAO), with the complex (in a manner so as to have 400 ppm of Mo in the lubricating composition) and 1% by weight of ZnDTP. The mixture is heated for 30 min at 60° C.

Example 2: Impact of the Ligand on the Stability of Molybdenum

(6) The lubricating compositions obtained in Example 1 were stored over a period of several months in order to assess their stability.

(7) The quantity of Mo was measured after 1 month, the results are provided in FIG. 1 which clearly shows the stability of the compositions of the invention as compared to the comparative compositions.

Example 3: Study of the Coefficient of Friction as a Function of Time

(8) The tests were carried out, for each of the compositions of Example 1, on a tribometer with a ball (Ø12 mm)-plane contact, both made of 10006 steel. The conditions used for these tests are as follows: a normal load of 7N, which corresponds to a maximum contact pressure of 540 MPa, a temperature of 110° C., a speed of 5 Hz, an amplitude of 5 mm. 5 A/R cycles are performed in 1 s, which corresponds to 18,000 cycles per hour.

(9) The results of the coefficient of friction for 10,000 cycles are as follows:

(10) Example 1.1:0.045

(11) Example 1.2:0.045

(12) Example 1.3:0.04

(13) Example 1.4:0.03

(14) These results show a reduction in the coefficient of friction by the compositions of the invention. This low coefficient of friction is maintained over time.