Alkoxylated phosphate esters for lubricant compositions

Abstract

The present invention concerns a composition suitable for working and shaping metals, in particular providing a lubricating effect, including polymers of the following formula: [R—O(—CH(CH.sub.3)—CH.sub.2O—).sub.n(CH.sub.2—CH.sub.2O—).sub.p—].sub.1+xP(═O)(OH).sub.2-x in which: R is a linear or branched, preferably linear, saturated or unsaturated hydrocarbon group, comprising between 8 and 12 carbon atoms; n is a number, which may or may not be an integer, between 6 and 20; p is a number, which may or may not be an integer, between 4 and 25; and x is a number between 0 and 1, and in particular between 0.1 and 0.9.

Claims

1. A lubricating formulation, comprising an emulsion and a polymer composition comprising polymers of formula (I) below:
[R—O(—CH(CH.sub.3)—CH.sub.2O—).sub.n(CH.sub.2—CH.sub.2O—).sub.p—].sub.1+xP(═O)(OH).sub.2-x  (I) wherein: R is a linear or branched, saturated or unsaturated hydrocarbon-based group comprising from 8 to 12 carbon atoms n is a number, integer or not, between 6.5 and 20 p is a number, integer or not, between 4 and 25 x is a number between 0 and 1 wherein the emulsion has an emulsion stability index greater than 95.

2. The lubricating formulation as claimed in claim 1, wherein the R group is a saturated or monounsaturated alkyl group.

3. The lubricating formulation as claimed in claim 2, wherein the polymers are polymers of following formula (la):
[CH.sub.3—(CH.sub.2).sub.11—O—(CH(CH.sub.3)—CH.sub.2O—).sub.n(—CH.sub.2—CH.sub.2O—).sub.p].sub.1+x—P(═O)(OH).sub.2-x  (Ia) wherein n, p and x are as defined.

4. The lubricating formulation as claimed in claim 1, wherein n is between 6.5 and 15.

5. The lubricating formulation as claimed in claim 1, wherein p is between 4.5 and 20.

6. The lubricating formulation as claimed in claim 1, wherein n is equal to 7.5 and p is equal to 5.

7. The lubricating formulation as claimed in claim 6, wherein the polymers are polymers of following formula (Ib):
[CH.sub.3—(CH.sub.2).sub.11—O—(CH(CH.sub.3)—CH.sub.2O).sub.7.5(—CH.sub.2—CH.sub.2O—).sub.5].sub.1+x—P(═O)(OH).sub.2-x  (Ib) wherein x is as defined.

8. The lubricating formulation according to claim 1 wherein the formulation is a lubricating formulation for cutting metals.

9. The lubricating formulation according to claim 1 wherein the formulation is a lubricating formulation for working or shaping aluminum.

10. The lubricating formulation according to claim 1, wherein x is a number between 0.1 and 0.9.

11. The lubricating formulation according to claim 2, wherein the R group is a linear, saturated or monounsaturated alkyl group.

12. The lubricating formulation according to claim 4, wherein n is between 7 and 10.

13. The lubricating formulation according to claim 5, wherein p is between 4.5 and 10.

14. The lubricating formulation according to claim 9 wherein the formulation is a lubricating formulation for cutting aluminum.

15. The lubricating formulation according to claim 1, wherein 5% to 30% by mass of the polymer is incorporated in an oil to form a mixture.

16. The lubricating formulation according to claim 15, wherein 5% to 15% of the mixture is mixed with 85% to 95% of water to form an emulsion.

Description

EXAMPLES

Example 1

(1) Composition Comprising a Polymer of Formula (Ib)

(2) Step 1: Alkoxylation (Propoxylation then Ethoxylation)

(3) The following reactants were used, in the proportions indicated in percentages by mass relative to the total mass of the reactants:

(4) Lauryl alcohol CH.sub.3—(CH.sub.2).sub.11—OH: 21.4%

(5) Potassium hydroxide: 0.1%

(6) Propylene oxide: 47.3%

(7) Ethylene oxide: 31.1%

(8) Acetic acid: 0.1%

(9) The lauric acid and the potassium hydroxide were charged to a recirculating reactor equipped with an internal stirrer. They were dehydrated under vacuum at 130° C. for 30 minutes (final moisture <0.030%).

(10) The propylene oxide was then introduced slowly, while cooling (exothermic reaction) in order to maintain the temperature at 130° C.±2° C.

(11) At the end of this propoxylation, the reaction medium was maintained at the temperature of 130° C.±2° C. until a constant pressure was obtained in the reactor, indicating the end of the consumption of the propylene oxide. The ethylene oxide was then introduced slowly, here too while cooling owing to exothermicity in order to maintain the temperature at 130° C.±2° C.

(12) At the end of this ethoxylation, the reaction medium was maintained at the temperature of 130° C.±2° C. until a constant pressure was obtained in the reactor, indicating the end of the consumption of the ethylene oxide.

(13) The medium was then cooled to 50° C. and neutralized by addition of acetic acid.

(14) Step 2: Formation of the Phosphate Ester

(15) The following reactants were used, in the proportions indicated in percentages by mass relative to the total mass of the reactants:

(16) lauryl alcohol alkoxylate formed in step 1: 94.25%

(17) H.sub.3PO.sub.2, 50% aqueous solution: 0.2%

(18) P.sub.2O.sub.5: 4.85%

(19) Water: 0.5%

(20) Hydrogen peroxide: 0.2%

(21) The lauryl alcohol alkoxylate formed in step 1 was charged at 40° C. to a reactor equipped with a magnetic stirrer and under a nitrogen atmosphere, and the aqueous solution of H.sub.3PO.sub.2 was immediately introduced so as to prevent an untimely oxidation at the end of the reaction.

(22) The P.sub.2O.sub.5 was added gradually, over a period of 5 hours, while maintaining the temperature at 60° C. After the end of the addition of P.sub.2O.sub.5, the reaction was left to continue at 80° C. for two hours.

(23) At the end of these two hours, water was added and the medium was left to cool to 60° C. Once this temperature was reached, the hydrogen peroxide solution was added.

Example 2

(24) Properties of the Polymer Compositions of Example 1

(25) The polymer composition synthesized in the preceding example was used for the preparation of emulsions under the conditions below:

(26) The composition as obtained at the end of example 1 (which is a polymer concentrate) was diluted in deionized water with a concentrate/added water weight ratio of 10/90 in a 100 ml graduated cylinder, while buffering the pH to 9 (MEA solution). The buffered aqueous medium was then mixed with a naphthenic oil (Nytex 810 from the company Nynas), with an aqueous medium/oil weight ratio of 20/80, whereby a first emulsion E1 was formed.

(27) At the same time, a second emulsion E2 was produced under the same conditions, but by replacing the deionized water with hard water comprising 347 mg/l of CaCO.sub.3 and 41.1 mg/l of MgCO.sub.3.

(28) Emulsifying Properties

(29) The short-term stability (after 30 minutes) and the long-term stability (after 7 days, at 40° C.) the emulsion of the emulsions E1 and E2 was evaluated as follows:

(30) Depending on the stability of an emulsion, several phases may appear in addition to the phase constituting the emulsion: a cream phase and/or an oil phase (generally supernatant) and/or an aqueous phase (generally below the emulsion). The stability may be assessed by measuring the respective volumes of the various phases, and an emulsion stability index I.sub.stability is defined as follows:
I.sub.stability=100 volume of the cream phase (expressed in ml)−5×volume of the oil oil phase (expressed in ml)−5×volume of the aqueous phase (expressed in ml)

(31) The emulsion is all the more stable, the higher its stability index is:

(32) The emulsion is said to be: “very stable” from 95 “acceptable” between 80 and 95 “not very stable” below 80 and down to 60 “unstable” below 60

(33) The dispersions E1 and E2 are of very stable type, with stability indexes of at least 95, reported in table 1 below:

(34) TABLE-US-00001 TABLE 1 short-term and long-term stability of the emulsions I.sub.stability after I.sub.stability after Emulsion 30 minutes 7 days at 40° C. E1 95 98 E2 96 97
Formation of Foam and/or Soap

(35) The foaming tendency was evaluated according to a test using a centrifugal pump and a 2 l graduated cylinder with a water jacket equipped with a side outlet close to the bottom of the cylinder. The emulsions were introduced into the cylinder up to the 1000 ml graduation mark, and they were pumped via the outlet at the bottom of the cylinder with a flow rate of 250 l/h, and reinjected via the pump into the cylinder, from a height of 390 mm above the 1000 ml graduation mark. The pumping was carried out with a view to obtaining formation of foam reaching the 2000 ml graduation mark, over a maximum duration t.sub.MAX of 5 hours: In the case where the 2000 ml graduation mark was reached before 5 hours: the time (t.sub.2000<t.sub.MAX) taken to reach the 2000 ml graduation mark (namely a foam volume V.sub.max corresponding to the volume between the 1000 ml and 2000 ml indices) was noted and the pumping was immediately stopped at t.sub.2000, then the volume of foam (V.sub.t2000+15min) above the 1000 ml graduation mark at the time t.sub.2000m+15 minutes was measured. In the case where the graduation mark was not reached after 5 hours: the volume of foam (V.sub.5h<V.sub.max) achieved above the 1000 ml graduation mark after five hours (t.sub.MAX) was measured and the pump was stopped after 5 hours, then the volume (V.sub.5h+15min) of foam above the 1000 ml graduation mark was measured 15 minutes after stopping the pump. For both cases, the following are defined: a pumping end time t.sub.P equal to t.sub.2000 in the first case and to t.sub.MAX in the second case a pumping end volume V.sub.P equal to V.sub.MAX in the first case and to V.sub.5h in the second case a volume of foam after resting for 15 minutes V.sub.R equal to V.sub.MAX in the first case and to V.sub.5h in the second case

(36) Two indices reflecting the profile of the foam are calculated as follows: Initial foam level index I.sub.M:
I.sub.M=100−10×(1+log(V.sub.P/t.sub.P) Defoaming index I.sub.D:
I.sub.D=100×(V.sub.P−V.sub.R)/V.sub.P

(37) The possible formation of soap on the walls was also determined visually.

(38) The results obtained for the dispersions E1 and E2 are reported in table 1 below:

(39) TABLE-US-00002 TABLE 2 foaming profiles of the emulsions Emulsion I.sub.M ID Soap formation E1 70 85 Very little E2 75 95 Very little
Wear-Resistant Properties

(40) They were evaluated using the ASTM D2670 method.

(41) The tribometer used is a Falex machine equipped with a “Pin and Vee blocks” system, immersed in the emulsions to be tested, at a temperature maintained at 24° C. (in a water-jacketed tank) and at 700 lbs for 10 min.

(42) The wear is determined by the loss of weight of the “Pin and Vee blocks” system, which reflects the degree of wear. A very small loss of weight of the order of 10 mg was obtained for the two emulsions, which reflects very good lubricating properties.

(43) Inhibition of Corrosion (Aluminum)

(44) The emulsions E1 and E2 were tested on three types of aluminum-based alloys, namely the alloys 2024, 6061 and 7075.

(45) Test specimens formed by each of the alloys were submerged in the emulsions in sealed bottles and maintained at 40° C. under these conditions for four weeks.

(46) The corrosion is evaluated visually, the surface turning to dark grey, or even to black, in the case of corrosion (“staining”). No significant corrosion was detected after four weeks, unlike controls in water.

(47) It is also possible to quantify the mass uptake of the samples after 4 weeks, which reflects the corrosion: less than 0.1% by mass with the emulsions E1 and E2 versus around 30% by mass with water.