AU737863B2 - A lubricant composition - Google Patents

Description

WO 98/22558 PCT/AU97/00778 A LUBRICANT COMPOSITION The present invention relates to a lubricant composition, and to a process for producing the lubricant composition.

Lubricants are extensively used for metal drilling, tapping and cutting operations to lubricate the tools and to guard the tools against rusting and/or excess wear.

Commonly used lubricants include petrochemical and vegetable oils. Whilst having suitable lubricating and corrosion inhibiting qualities, these known compositions are disadvantageous in that they give off toxic fumes when subjected to high temperatures in the machinery.

In addition, known compositions are unsuitable for use in cold climates since they solidify in cool storage conditions and must be warmed to be applied to machinery.

Another problem associated with such compositions is that they are difficult to remove from machinery during cleaning.

In addition, there is increasing recognition that in addition to lubricating, corrosion inhibiting and heat stability properties, lubricant compositions should be biodegradable and resistant to bacterial build up.

Accordingly, it is an object of the present invention to provide a lubricant composition that inhibits corrosion, is heat stable, biodegradable, resistant to bacterial build up and non-toxic.

WO 98/22558 PCT/AU97/00778 -2- According to the present invention there is provided a lubricant composition comprising a wax ester having a monounsaturated fatty acid content of between 60 wt% and wt9 of the total fatty acid content of the wax ester.

It is preferred that the monounsaturated fatty acid content be between 75 and 95wt% of the total fatty acid content of the wax ester.

It is preferred that the wax ester be obtained from fish oil.

It is particularly preferred that the fish oil be extracted from a deep sea marine species, such as Orange Roughy (Hoplostethus atlanticus) or Dory.

The oil extracted from Orange Roughy and other deep sea marine species is significantly different from the oil extracted from other more common fish species. It is very high in monounsaturated constituents, and contains very low levels of polyunsaturated fatty acids. In addition, the oil stored in these species is stored as a wax ester and not as a triglyceride. Therefore, the fish oil of deep sea marine species is the most convenient source of wax esters having a monounsaturated fatty acid content of between and 95wt% of the total fatty acid content.

It is preferred that the lubricant composition further comprises an emulsifier.

It is preferred that the emulsifier be present in the lubricant composition in an amount up to It is particularly preferred that the emulsifier be present in an amount up to 3wt%, and more particularly in an amount of between 0.5wt% and 3wt% of the lubricant composition.

WO 98/22558 PCT/AU97/00778 3 It is preferred that the emulsifier has a hydrophilic/lipophilic balance of between 5 and 9.

It is preferred that the emulsifier be biodegradable as determined by AS 1792-1976.

It is preferred that the emulsifier be non-toxic.

The emulsifier may be formed in situ, eg, by reaction of polyethylene glycol and the oil to form polyethylene glycol esters or neutralisation with an alkali of any free fatty acids to form soaps.- Typically, the emulsifier comprises one or more of polyethylene glycol 200 mono oleate, polyethylene glycol 400 dioleate, and laurylpolyethylene glycol ether.

It is preferred that the lubricant composition further comprise a second marine oil component.

It is particularly preferred that the second marine oil component comprises diacylglyceryl ether.

Diacylglyceryl ether is obtainable from shark liver oil oil from the liver of the shark species Etmopterus granulosus and other species.

Diacylglyceryl ethers are similar in structure to triacylglycerols but have one of the ester groups replaced by an ether, which makes the diacylglyceryl ethers much more stable. It has been found that the inclusion of this component in the lubricant composition provides a lubricant composition with advantageous properties.

It is preferred that the diacylglyceryl ether be present in the lubricant composition in an amount of up to 3wt%.

WO 98/22558 PCT/AU97/00778 -4- It is particularly preferred that the diacylglyceryl ether be present in an amount of between 0.5wt% and 3wt%.

It is also preferred that the lubricant composition contain no or at most a low concentration of polyunsaturated fatty alcohols or acids as these are potential sites for oxidation and the development of rancidity.

It is particularly preferred that the lubricant composition contains less than 10wt% of polyunsaturated fatty alcohols or acids.

It is more particularly preferred that the lubricant composition contains less than 5wt% of polyunsaturated fatty alcohols or acids.

According to the present invention there is also provided a process for producing the lubricant composition from a fish oil, the process comprising the steps of: subjecting the fish oil to vacuum steam distillation, and (ii) mixing the fish oil with an emulsifier in the appropriate proportion.

It is preferred that the process further comprises a step in which the free fatty acids are removed from the fish oil. This may be achieved, for example, by washing the oil with a dilute alkali solution such as dilute sodium or potassium hydroxide solution. The free fatty acid removal' step is required when producing a lubricant composition from poor quality fish oil. As a general rule, this step is not normally required.

It is also preferred that the process comprises a filtration step. Filtration may be conducted with, for WO 98/22558 PCT/AU97/00778 5 example, activated charcoal.

It is also preferred that the process comprises mixing of the fish oil with diacylglyceryl ether. The diacylglyceryl ether may be added together with the emulsifier or separately.

The present invention will now be described in further detail with reference to the following examples.

Example 1 Analysis of the Wax Ester Composition of a Typical Orange Roughy Oil Orange Roughy oil comprises approximately 18wt% of the weight of the fish. A major part of the oil is found in the swim bladder. Wax esters constitute approximately 88 97wt% of the Orange Roughy oil and the remainder of the oil is largely triacylglycerol.

The fatty acid and fatty alcohol chain length distribution of a typical Orange Roughy oil is presented in Table 1.

WO 98/22558 WO 9822558PCT/AU97/00778 -6 Table 1 Percentage Composition Component Fatty acid Fatty alcohol (Wt96) (carbon chain length:degree of unsatur ation) 14:1 0.2 14:0 1.12.

15:0 16:1 8.8 1.1 16:0 4.4 21.9 17:1 A. 1 0.8 17:0 0.2 18:2 6.8 18:1 47.3 14.1 18:1 3.8 3.1 18:0 3.0 7.4 20:5w3 0.7 20:1 13.8 23.7 20:1 0.5 1.2 20:0 0.1 0.8 22:6w3 22:1 4.5 11.9 22:1 1.0 3.3 22:1 0.3 24:1 0.1 0.4 24:1 0.4 2.9 0.1 24:0_ 0.1 other 1.6 3.1 total 100.0 100.0 WO 98/22558 PCT/AU97/00778 7 Example 2 Analysis of the Diacylglyceryl Ether Content of a Typical Shark Liver Oil Oil extracted from the liver of the shark species Etmopterus granulosus was separated into its two major components, squalene and diacylglyceryl ether.-, The carbon chain length distribution of the fatty acids and the acyl groups of the diacylglyceryl ether were analysed. The distribution of these groups is set out in Table 2.

Table 2 Component Fatty Acid Alkyl chain (wt%) 14:0 0.8 1.8 14:1 0.4 15:0 0.3 1.7 16:0 12.7 14.7 6:1 (n-5)c 0.2 16:1 (n-7)c 1.3 5.1 16:1 (n-9)c 17:0 0.2 1.4 17:0 branched i 0.3 2.2 17:0 branched a 0.5 1.4 17:1 branched a 0.4 17:1 branched i 18:0 1.7 18:1 (n-5)c 0.7 18:1 (n-7)c 2.6 18:1 (n-9)c 22.4 50.2 18:2 0.4 3.4 20:0 0.2 WO, 98/22558 WO 9822558PCTIAU97/00778 -8 Component Fatty Acid Alkyl chain (wt%) 20:1 23.1 20:5 (n-3)/20:4 0.3 22:1 27.6 24:1 other 0.8 0.1 total 100 100 Example 3 Lubricant Compositions The formulations of preferred lubricant compositions are set out in Table 3.

Table 3 No No. Component Wt96 mI 1 0 orange Roughy oil 97 -polyethylene glycol 3 2 orange Roughy oil 96 polyethylene glycol 200 2 monooleate 2 diacylglyceryl ether 3 0 Orange Roughy oil 99 polyethylene glycol 400 dioleate 1 4 0 D~ory oil *polyethylene glycol monooleate 4 *diacyiglyceryl ether 1 *Orange Roughy oil 94 *polyethylene glycol 200 6 monooleate 6 *Orange Roughy oil 96 *polyethylene glycol 400 dioleate 2 *diacylglyceryl ether 2 WO 98/22558 PCT/AU97/00778 9 Product Testing Results The product numbered 6 in Table 3 was submitted to testing in a variety of operations. The results of the tests are set out in Table 4.

Table 4 A. Test 316 Stainless steel (180 BHN) drilling, tapping and counter boring.

Results Tool life extended by 25wt% compared with known lubricants Rocol, Devcon safe tap and black oil.

B. Test Copper, aluminium, mild steel and stainless steel (316).

Results Good heat stability and flow characteristics. No bacterial indications compared with the known lubricant Shell microcool, which presented bacterial problems within three weeks of first use.

C Test Mild steel, brass, aluminium.

Results Performed well on all metals with good workability and finished metal brightness.

D Test Mild Steel thread cutting in reinforcing bars used in concrete framework.

Results Visibly superior thread finish compared with known cutting fluids. Tool life of cutter was increased by an estimated 200- 300wt%.

E Test Mild steel.

Results Improvement in the finish of the worked metal workpiece. Extended tool life. No toxic fumes produced. Decrease in occurrence of industrial dermatitis which had been experienced with known cutting oils.

WO 98/22558 PCT/AU97/00778 10 In summary, the lubricant composition of the invention is shown to inhibit corrosion, extend tool life, is heat stable, non-toxic, biodegradable and resistant to bacterial build up.

Example 4 Process for Producing Lubricant Composition 2 of Table 3 Orange Roughy oil was subjected to washing with a dilute solution of sodium hydroxide (1M) to remove the free fatty acids.

The washed Orange Roughy oil was subjected to filtration through activated charcoal to remove traces of impurities.

The filtered Orange Roughy oil was subjected to vacuum steam distillation to further purify the oil.

Finally the fish oil was mixed with equal amounts polyethylene glycol 200 monooleate and diacylglyceryl ether obtained from shark liver oil to provide the final lubricant composition.

This composition was found to exhibit similar characteristics to the lubricant composition tested in Example 3.

Many modifications may be made without departing from the spirit and scope of the invention.

Claims (19)

1. A method of using a lubricant composition in a metal drilling, tapping or cutting operation, including the step of applying the lubricant composition to the metal undergoing the drilling, tapping or cutting operation wherein the lubricant composition includes a naturally occurring wax ester having a monounsaturated fatty acid content of between 60 wt% and 95 wt% of the total fatty acid content of the wax ester.

2. A method according to claim 1 wherein the monounsaturated fatty acid content of the lubricant is between 75 wt% and 95 wt% of the total fatty acid content of the wax ester. 15 3. A method according to claim 1 or claim 2 wherein the wax ester is obtained from fish oil

4. A method according to claim 3 wherein the fish oil is extracted from a deep sea marine species. A method according to claim 4 wherein the fish oil is extracted from orange roughy fish or dory fish.

6. A method according to any one of the preceding claims in which the lubricant further includes an emulsifier.

7. A method according to claim 6 wherein the 25 emulsifier comprises up to 25 wt% of the total composition.

8. A method according to claim 7 wherein the emulsifier comprises up to 3 wt% of the total composition.

9. A method according to any one of claims 6 to 8 wherein the emulsifier has a hydrophilic/lipophilic balance of between 5 and 9. A method according to any one of claims 6 to 9 wherein the emulsifier is biodegradable and/or non-toxic.

11. A method according to any one of claims 6 to wherein the emulsifier is formed in situ.

12. A method according to any one of claims 6 to 11 wherein the emulsifier includes polyethylene glycol 200 H:\mbourke\Keep\Speci\49350-97 SPECI.doc 27/06/01 12 mono oleate, polyethylene glycol 400 dioleate, laurylpolyethylene glycol ether or combinations thereof.

13. A method according to any one of the preceding claims in which the lubricant further includes a second marine oil component.

14. A method according to claim 13 wherein the second marine oil component includes diacyclglyceryl ether. A method according to claim 13 or claim 14 wherein the second marine oil component comprises up to 3% by weight of the total weight of the composition.

16. A method according to any one of the preceding claims in which the lubricant includes less than 10 wt% of •polyunsaturated fatty alcohols or acids.

17. A method of producing a lubricant composition for 15 use in a metal drilling, tapping or cutting operation from a fish oil, the process including the steps of: e. subjecting the fish oil to vacuum steam distillation, and (ii) mixing the fish oil with an emulsifier in the appropriate proportions, wherein the lubricant composition comprises a naturally occurring wax ester having a monounsaturated fatty acid content of between wt% and 95 wt% of the total fatty acid content of the wax ester *D 25 18. A method according to claim 17 further including the step of removing the free fatty acids from the fish oil.

19. A method according to claim 17 or 18 which further includes a filtration step.

20. A method according to any one of claims 17 to 19 further including the step of mixing fish oil with diacylglyceryl ether.

21. A method according to any one of claims 17 to in which the lubricant produced is used in the method of any one of claims 1 to 16.

22. A method of lubricating tools used in metal drilling, tapping or cutting operations including the H:\mbourke\Keep\Speci\49350y-97 SPECI.doc 27/06/01 13 step of applying to the tool the lubricant composition produced by the method of any one of claims 17 to 21.

23. A method of using a lubricant composition substantially as herein before described with reference to any one of the foregoing examples.

24. A method for producing a lubricant composition substantially as herein before described with reference to any one of the foregoing examples. A method of lubricating tools substantially as herein before described with reference to any one of the foregoing examples. Dated this 27th day of June 2001 DEEP SEA OILS LIMITED 15 By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia 9 9 0* H:\mbourke\Keep\Speci\4935-97 SPECIdoc 27/06/01