Water based metal working fluid composition

Abstract

This invention is a composition of an ester resulting from the reaction of an oligomer of ethylene oxide in presence or a catalyst, with fatty acids. The resulting water based metal working fluid additive is useful as it imparts property of stable micro-emulsion and helps improving the wear life, coefficient of friction and other tribological properties among other uses.

Claims

1. Stable micro emulsion based metal working fluid composition comprising reaction products from a reaction of fatty acid ranging from 26.0-29% w/w with an oligomer of ethylene oxide ranging from 56.0-58% w/w in the presence of water, a promoter and a catalyst, wherein the said composition is readily biodegradable and exhibits self-emulsifying property.

2. Stable micro emulsion based metal working fluid composition as claimed in claim 1, wherein the said promoter is at a concentration ranging from 13.8-15.2% w/w and a catalyst ranging from 0.01-0.15% w/w.

3. Stable micro emulsion based metal working fluid composition as claimed in claim 1, is prepared by a process comprising the steps of: a) charging an oligomer of ethylene oxide into a round bottom flask b) charging fatty acid and a catalyst c) maintaining the temperature at 150-180 C. and stirring for 1-2 hrs d) adding promoter to the reaction mixture and raising the temperature to 200-250 C. and stirring for 4-5 hours.

4. Stable micro emulsion based metal working fluid composition as claimed in claim 1, wherein the said composition has an acid number in the range of 15-25 mg KOH/g.

5. Stable micro emulsion based metal working fluid composition as claimed in claim 1, wherein the said fatty acid is derived from the group consisting of Jatropha gossypifolia seed oil; Hevea brasiliensis seed oil, Ricimus communis seed oil, Gossypium arboreum seed oil and Glycine max seed oil.

6. Stable micro emulsion based metal working fluid composition as claimed in claim 2, wherein said promoter is an acid having 4-8 carbon atoms.

7. Stable micro emulsion based metal working fluid composition as claimed in claim 2, wherein said catalyst is hypophosphorus acid.

8. Stable micro emulsion based metal working fluid composition as claimed in claim 1, wherein the said oligomer contains 6-20 carbon atoms.

9. Stable micro emulsion based metal working fluid composition as claimed in claim 8, wherein the molecular weight of the said oligomer is in the range of 280-540 Da.

10. Stable micro emulsion based metal working fluid composition as claimed in claim 1, wherein the said micro-emulsion is achieved between ester to water at a ratio in the range of 2:98-8:92.

11. Stable micro emulsion based metal working fluid composition as claimed in claim 1, wherein the total molecular weight of the said composition is in the range of 650-1200 Da.

12. A method of use of a stable micro emulsion based metal working fluid composition as claimed in any one of the preceding claims as a lubricant between interacting metal surfaces including at least one step of rolling, drawing, stamping, cutting, bending and compressing.

13. Stable micro emulsion based metal working fluid composition as claimed in claim 5, wherein the said fatty acid is ricinoleic acid derived from Ricimus communis seed.

14. Stable micro emulsion based metal working fluid composition as claimed in claim 13, wherein the said fatty acid contains 5-20 carbon atoms.

15. Stable micro emulsion based metal working fluid composition as claimed in claim 14, wherein the molecular weight of said fatty acid is in the range of 280-650 Da.

Description

BRIEF DESCRIPTION OF FIGURES

(1) FIG. 1Degradation curve for the sample

(2) FIG. 2Degradation curve for the sample

(3) FIG. 3Degradation curve for toxicity control

(4) FIG. 4Comparative analysis for Tapping Torque (Aluminium Microtap Medium)

(5) FIG. 5Comparative analysis for Tapping Torque (Steel Microtap Medium)

DETAILED DESCRIPTION OF THE PRESENT INVENTION

(6) The present invention provides a novel composition obtained by reacting oligomer of ethylene oxide having repeating units with fatty acids in the presence of acidic catalyst in a two stage process.

(7) Stage I: In a 4 necked round bottom flask equipped with an overhead stirrer, thermometer socket, stopper and distillation condenser was charged with an oligomer of ethylene oxide ranging from 50-60% w/w, fatty acid ranging from 25-30% w/w and 0.12% of 50% of catalyst, temperature was maintained between 150-180 C. and reaction mixture was stirred for 1-2 hrs. The catalyst used in the above reaction is hypophosphorus acid.

(8) Completion of Stage I: It was determined by the acid value, after an hour of the reaction acid value was checked and acid value of less than 25 mg KOH/g determines the completion of the reaction.

(9) Stage II: Promoter ranging from 13.8-15.2% w/w was added to the reaction mixture obtained from stage I and the reaction was continued to about 4-5 hours at a temperature ranging from 200-250 C. until the acid value was in the range of 15-25 mg KOH/g. Typically promoter have 4-10 carbon atom, preferably 4-8 carbon atom and most preferably up to 7 carbon atom, e.g., 4-6; to form an ester corresponding to the formula:

(10) ##STR00002##

(11) R1 and R2 groups are selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, primelic acid; suberic acid, azelaic acid, sebacic acid, undecanoic acid and dodecanoic acid, 2-hydroxy butanoic acid, 2-hydroxy pentanoic acid, 4-hydroxy hexanoic acid, 12-hydroxy octadecenoic acid, 15-hydroxy hexadecanoic acid, 6-hydroxy decanoic acid, linoleic acid, linolinic acid, 2-Hydroxy octadecenoic acid, 2-Hydroxytetracosanoic acid, 2-hydroxy-15-tetracosenoic acid, they are typically fatty acids having 15-24 carbon atoms, preferably 15-22 carbon atoms and most preferably up to 20 carbon atoms, e.g., 15-18 carbon atoms. The ethylene oxide which reacts with the fatty acid can be polyethylene or polypropylene or polybutylene or polyamides or polyesters or polysulfones or polyacrylates or polymethylacrylates or epoxies or polyacetylene or fluorinated polymers copolymers and mixtures thereof. They are typically oligomers having 4-30 carbon atoms, preferably 10-25 carbon atoms and most preferably up to 22 carbon atoms, e.g., 10-19 carbon atoms.

(12) The weight average molecular weight of the ester obtained from the above process can vary from 650-1200 Da wherein the weight average molecular weight for the fatty acid can vary from 280-650 Da and for the oligomer it can vary from 280-540 Da.

(13) Another embodiment of the present invention is to provide a novel composition possessing self-emulsification property.

(14) Another embodiment of the present invention is to provide a novel composition which provides a stable micro emulsion which imparts lubrication equivalent to that of imparted by a mineral oil.

(15) Another embodiment of the present invention is to provide a novel composition, which is readily biodegradable and selected from group of plants consisting of Jatrophagossypifolia seed oil; Heveabrasiliensis seed oil, Ricimuscommunis seed oil Gossypiunarboreum seed oil, Glycine max seed oil.

(16) Briefly, and in general terms, by way of example and not limitation, one aspect of the present invention resides in a water based metal working fluid compositions providing stable micro-emulsion when mixed with water.

(17) Additionally, by way of example and not limitation, another aspect of the present invention resides using water based metal working fluid compositions for improving the wear life, coefficient of friction and other tribological properties of surfaces lubricated with a liquid or solid lubricant.

(18) The technology of the instant application is further elaborated with the help of following examples. However, the examples should not be construed to limit the scope of the invention.

EXAMPLES

Example1: 4 Ball Wear Scar Test

(19) Procedure:

(20) Three 12.7 mm diameter steel balls are clamped together and covered with the test lubricant, a fourth steel ball of same diameter (referred as top ball) is placed with a force of 392 N in to the cavity formed by the three clamped balls. The temperature of the test lubricant is maintained at 75 C. and the top ball is rotated at 1200 rpm for 60 minutes.

(21) Results:

(22) Wear scar formed on the three clamped steel balls is measured using microscope and the average of three values are reported (ASTM4172).

(23) Lubricants are compared by using the average size of scar diameter

(24) TABLE-US-00001 Sl. No. Test Sample Scar diameter 1. Instant composition 0.438 mm 2. Standard 0.650 mm

Example2: HFRR Test (High Frequency Reciprocating Rig)

(25) Procedure:

(26) Test sample is loaded in the test reservoir, to the test sample a test disk is completely submerged by a vibrating arm holding a steel ball and which is loaded with 1 kg of mass. The ball is caused to rub against the disk with a 1 mm stroke length at a frequency of 50 Hz for 60 minutes at a temperature of 100 C.

(27) Results:

(28) TABLE-US-00002 Test Results (ASTM D 6079) Coefficient of Wear scar Film Sl. No. Test Sample friction diameter Potential 1. Instant composition 0.015 0.386 mm 99.94 2. Standard 0.031 0.453 mm 63.54

Example3: Test for Hardness Water Stability

(29) Destabilization of the emulsion causes oil separation and loss of fluid concentration hence a test for checking the stability was conducted by dissolving 5 gm sample (instant invention) in 95 ml water. The resulting emulsion was kept for 21 days at room temperature and the stability/separation of the same was checked every day.

(30) Results:

(31) TABLE-US-00003 Sl. No. ppm Instant composition Standard 1 200 Clear micro-emulsion Clear micro-emulsion 2 400 Clear micro-emulsion Clear micro-emulsion 3 600 Clear micro-emulsion Clear micro-emulsion 4 800 Clear micro-emulsion Semi Translucent emulsion 5 1000 Clear micro-emulsion Translucent emulsion 6 1200 Clear micro-emulsion Translucent emulsion 7 1500 Clear micro-emulsion Thick emulsion 8 3000 Clear micro-emulsion Thick emulsion

Example4: Test for Determining TAN

(32) To determine the acid or base number, the sample is dissolved in a mixture of toluene and isopropyl alcohol

(33) Containing a small amount of water, and the resulting single phase solution is titrated at room temperature with standard alcoholic base or alcoholic acid solution respectively, to the end point indicated by the colour change of the added p-naphtholbenzein solution (Orange in acid and green-brown in base). To determine the strong acid number, a separate portion of the sample is extracted with hot water and the aqueous extract is titrated with potassium hydroxide solution, using methyl orange as an indicator.

(34) Result:

(35) TABLE-US-00004 Sl. No. Test Sample Method Results 1. Instant composition ASTM D974 15.54 2. Standard ASTM D974 60.06

Example5: Test for Determining Colour

(36) Using a standard light source, a liquid sample is placed in the test container and compared with coloured glass disks ranging in value from 0.5 to 8.0. When an exact match is not found and the sample colour falls between two standard colours, the higher of the two colours is reported.

(37) Result:

(38) TABLE-US-00005 Sl. No. Test Sample Method Results 1. Instant composition ASTM 1500 <2.0 2. Standard ASTM 1500 <7.0

Example6: Test for Determining Tapping Torque (Aluminium Microtap Medium)

(39) A tapping torque machine Megatap-II was used for tapping torque measurements. The instantaneous tapping torque was measured throughout the depth of the cut. The machine was interfaced with a personal computer to facilitate data analysis, M-41.25 mm spiral pointed taps were used. The aluminium substrate TTT system 3.2583 M4 F/3.7 having dimension of 1254718 mm/30 mm, 140 drilled array at 6 mm was used for the experiment. All test material were cleaned, tapping occurred at a rotational speed of 1200 r/min. Holes to be tapped were chosen at random to minimize systematic spatial bias.

(40) Result:

(41) Aluminium Medium:

(42) TABLE-US-00006 Sl. No. Test Sample Results 1. Instant composition 56 Ncm 2. Standard 117 Ncm
Steel Medium:

(43) TABLE-US-00007 Sl. No. Test Sample Results 1. Instant composition 176 Ncm 2. Standard 332 Ncm

Example7: Test for Determining Biodegradability Using OECD 301-B CO2 Evolution

(44) The principle of the widely used CO2 evolution test (OECD 301 B), also known as the Sturm test, was the determination of the ultimate biodegradability of organic compounds by aerobic microorganisms, using a static aqueous test system and the evolution of CO2 as the analytical parameter. The biogenous CO2 formed during the microbial degradation was trapped in two external adjacent vessels. Samples were taken at regular intervals to determine and to calculate the amount of CO2 produced. This evolved CO2 was compared with the calculated theoretical amount (ThCO2); and the degree of biodegradation was expressed as a percentage.

(45) Result:

Guidelines of OECD 301-B: CO2 Evolution

(46) TABLE-US-00008 Sl. No. Test Sample Results Requirement Conformity 1. Biodegradation % 96.1 >60 Yes (elaborated from table 1 to table 3)

(47) TABLE-US-00009 TABLE 1 Biodegradation for Test sample Cumulative CO.sub.2 Produced CO.sub.2 (sample- Test (mg) Blank (mg) blank.sub.) (mg) % Degradation Days Vsl-1 Vsl-2 Vsl-1 Vsl-2 Avg- Vsl-1 Vsl-2 Vsl-1 Vsl-2 Avg.- Total %- 3 16.18 18.46 2.45 4.74 3.59 12.58 14.87 52.90 62.51 57.70 57.70 7 12.60 10.30 3.46 10.33 6.90 5.70 3.40 23.98 14.31 19.14 76.85 10 11.09 8.80 6.51 6.51 6.51 4.58 2.29 19.23 9.62 14.43 91.27 14 16.77 16.77 23.63 7.62 15.62 1.14 1.14 4.81 4.81 4.81 96.08 17 9.31 9.31 16.18 2.42 9.31 0.00 0.00 0.00 0.00 0.00 96.08 Vsl = vessel, Avg = Average

(48) For sample [Theoretical or ThCO.sub.2=23.79 mg and Total Organic Carbon or TOC content=63%]

(49) TABLE-US-00010 TABLE 2 Biodegradation for reference Cumulative CO.sub.2 Produced CO.sub.2 (sample- Test (mg) Blank (mg) blank.sub.) (mg) % Degradation Days Vsl-1 Vsl-2 Vsl-1 Vsl-2 Avg- Vsl-1 Vsl-2 Vsl-1 Vsl-2 Avg.- Total %- 3 9.31 4.74 2.45 4.74 3.59 5.72 1.14 54.74 10.95 32.84 32.84 7 8.04 12.62 3.46 10.33 6.90 1.14 5.72 10.95 54.74 32.84 65.68 10 8.80 8.80 6.51 6.51 6.51 2.29 2.29 21.89 21.89 21.89 87.58 14 16.77 16.77 23.63 7.62 15.62 1.14 1.14 10.95 10.95 10.95 98.53 17 9.31 9.31 16.18 2.45 9.31 0.00 0.00 0.00 0.00 0.00 98.53

(50) For reference [Theoretical or ThCO.sub.2=10.45 and Total Organic Carbon or TOC content=27.66%]

(51) TABLE-US-00011 TABLE 3 Biodegradation of toxicity Cumulative CO.sub.2 Produced CO.sub.2 (sample- Test (mg) Blank (mg) blank.sub.) (mg) % Degradation Days Vsl-1 Vsl-2 Vsl-1 Vsl-2 Avg- Vsl-1 Vsl-2 Vsl-1 Vsl-2 Avg.- Total %- 3 18.46 23.04 2.45 4.74 3.59 14.87 19.45 43.43 56.80 50.12 50.12 7 17.19 12.62 3.46 10.33 6.90 10.30 5.72 30.07 16.71 23.39 73.50 10 8.80 13.38 6.51 6.51 6.51 2.29 6.86 6.68 20.05 13.36 86.87 14 21.34 16.77 23.63 7.62 15.62 5.72 1.14 16.71 3.34 10.02 96.89 17 9.31 9.31 16.18 2.45 9.31 0.00 0.00 0.00 0.00 0.00 96.89

REFERENCE

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