Industrial Fluid

Abstract

An industrial fluid is disclosed. The fluid comprises an oleaginous component, an aqueous component, and a surfactant dispersed in the aqueous component. The average micelle diameter follows a Gaussian distribution having a mean, , and wherein the standard deviation is less than or equal to 0.2. The industrial fluid is also substantially free from defoamers or anti-foam compounds.

Claims

1. Industrial fluid comprising an emulsion of: An oleaginous component; An aqueous component; and A surfactant; Wherein the fluid comprises micelles of the oleaginous or the aqueous component with the surfactant, and wherein the average micelle diameter follows a Gaussian distribution having a mean and standard deviation u, and wherein the standard deviation is less than or equal to 0.2.

2. Industrial fluid as claimed in claim 1, wherein the industrial fluid does not contain defoamers or anti-foam compounds.

3. Industrial fluid as claimed in claim 1 or 2, wherein the surfactant is bound within micelles of the oleaginous or the aqueous component, such there is substantially no unbound surfactant present in the fluid.

4. Industrial fluid as claimed in any of claims 1 to 3, wherein the micelle is a normal-phase micelle, and the oleaginous component forms the centre of the micelle.

5. Industrial fluid as claimed in claim 4, wherein the surface comprises at least one surfactant monomer layer.

6. Industrial fluid as claimed in any of claims 1 to 5, wherein the mean average micelle diameter is 0.3 m and the standard deviation is 0.06 m.

7. Industrial fluid as claimed in any of claims 1 to 6, wherein the average micelle diameter is 0.3 m.

8. Industrial fluid as claimed in any of claims 1 to 7, wherein the structure of the surfactant dictates the structure of the micelle.

9. Industrial fluid as claimed in any of claims 1 to 3, wherein the micelle is an inverse-phase micelle, and at least some of the aqueous component forms the centre of the micelle.

10. Industrial fluid as claimed in any preceding claim, wherein in use, the emulsion is undiluted, diluted or an additive to a carrier fluid.

11. Industrial fluid as claimed in any preceding claim, wherein the industrial fluid is a lubricating fluid and wherein the oleaginous component comprises a lubricating composition.

12. Industrial fluid as claimed in claim 11, wherein the lubricating composition is a fully formulated lubricant.

13. Industrial fluid as claimed in claim 12, wherein the lubricating composition is a Group I, II, II, IV or V base oil.

14. Industrial fluid as claimed in claim 11, wherein the lubricating composition comprises a blend of components, at least one of which has lubricating properties.

15. Industrial fluid as claimed in any preceding claim, wherein the surfactant is an ionic surfactant, a non-ionic surfactant or a mixture thereof.

16. Industrial fluid as claimed in any of claims 1 to 10, wherein the industrial fluid is used in a destructive metalworking process.

17. Industrial fluid as claimed in any of claims 1 to 10, wherein the industrial fluid is used in a deformation metalworking process.

18. Industrial fluid as claimed any of claims 1 to 16 wherein the industrial fluid is used in an automotive application.

19. Industrial fluid as claimed in any of claims 1 to 16 wherein the industrial fluid is used in an industrial, marine or subsea process.

20. Industrial fluid as claimed in any of claims 1 to 10, wherein the industrial fluid is an energy dissipating fluid.

21. Industrial fluid as claimed in any of claims 1 to 10, wherein the industrial fluid is an energy generating fluid.

22. Industrial fluid as claimed in any of claims 1 to 10 wherein the industrial fluid is a fuel.

23. Industrial fluid as claimed in claim 22, wherein the industrial fluid is an energy transmission fuel.

24. A method of forming an industrial fluid, comprising: Forming a first fluid comprising a surfactant; Forming a second fluid comprising an oleaginous compound; Mixing the first fluid and the second fluid under a shear force to produce an intermediate fluid; and Mixing an aqueous fluid and the intermediate fluid under laminar flow to create an industrial fluid.

25. Method of making an industrial fluid in accordance with any of claims 1 to 23 using the method as claimed in claim 24.

26. An industrial fluid made using the method of claim 24.

Description

[0021] The following non-limiting examples are in relation to industrial fluids used in metalworking processes.

[0022] Metalworking fluid is a lubricant used in either a destructive metalworking process (one where chips are produced, such as milling) or a deformation metalworking process (one where a material is deformed or shaped such that no chips are produced, for example as steel rolling). Metalworking fluids are formulated both for the specific type of metal they are used on (such as steel) and for the process they are used for (such as wire drawing). A typical metalworking fluid composition suitable for a destructive process (milling) is characterised by the illustrative composition:

[0023] 10 to 50 wt % of lubricating composition;

[0024] 3.0 to 8.0 wt % of surfactant;

[0025] 5.0 to 10 wt % corrosion inhibitor;

[0026] 0 to 1.0 wt % yellow metal;

[0027] 0 to 8.0 wt % esters; and

[0028] water to balance.

In this example an industrial fluid in accordance with embodiments of the present invention may comprise all of the above elements except for water, creating an emulsion that requires water in order to be diluted for use, or the industrial fluid may be created as a final emulsion and used in an undiluted form. Suitable surfactants include, but are not limited to, C.sub.16-C.sub.18 fatty alcohol ethoxylateswith an ethoxylation range of 0-9 moles (fatty alcohol polyglycol ethers); C.sub.16-C.sub.18 fatty alcohol ethoxylate and propoxylate; C.sub.6/C.sub.8/C.sub.16-18 alkyl polyoxyethylene ether carboxylic acids with a 2 to 9 mole ethoxylation range; alkyl ether ethoxylate mono phosphate esters-alkyl chain C.sub.18, with a 2 to 5 mole ethoxylation range; ethoxylated oleine with a 6/9 mole ethoxylation range; and polyethylene glycol esters of C.sub.16-C.sub.18 fatty acids. Combinations of various surfactants, as mentioned above, may be particularly advantageous.

[0029] Suitable corrosion inhibitors include, but are not limited to amine/alkali salts of short chain carboxylic mono acids, di acids and tri acids, short chain acidic phosphate esters, including alkoxylated esters, semi-succinate half esters, amide-carboxylic acid salts, fatty amides, and amine and alkali sulphonates or their derivatives. Yellow metals include benzotriazole or its derivatives and tolutriazole or its derivatives. Suitable esters include, but are not limited to TMP (trimethylol propane) mono, di and tri esters of C.sub.8-C1.sub.8 fatty acids, glycol esters of predominantly olely fatty acids, methyl or isopropyl esters of predominantly olely fatty acids or triglycerides, natural triglycerides, such as rapeseed, and modified natural oils such as blown rapeseed. Biocides (typically amine compounds) may also be included if desired. These include, but are not limited to, formaldehyde releasing agents including ortho-formal, hexahydratriazine and derivatives, methylene bis morpholene, oxazoladine and derivatives, isothiazolinones and derivatives, and iodo propyl butyl carbamate-fungicide.

[0030] Other additives used in other lubricant systems, and other suitable examples of those materials listed above, will be apparent to those skilled in the art.

[0031] In the present invention it has been appreciated that the method and apparatus disclosed in US2013/0201785, available from Clariant AG under the name NanoCon when applied to the field of industrial fluids offers many advantages over traditional emulsification methods. This is particularly the case for water miscible fluids, such as those used in metalworking. In order to test whether ensuring that substantially all the surfactant is bound within the structure of a micelle does indeed reduce the foaming of an industrial fluid, a sample of a commercially available sub-micron emulsion, NanoGel CCT (available from Clariant Produkte (Deutschland) GmbH) was examined NanoGel CCT comprises caprylic/capri triglyceride, water, glycerine. Laureth-23, sodium dicocoylethlyenediamine PEG-15 sulfate, sodium lauroyl lactylate, behenyl alcohol, glyceryl stearate and glyceryl stearate citrate. The oleaginous components are comprised within micelles each having three surface layers of surfactant, accounting for substantially all of the surfactant within the emulsion. Sample 1 comprised 10 wt % NanoGel CCT and 90 wt % water, and Sample 2 comprised 5 wt % NanoGel CCT and 95% water. These were evaluated against a Control Sample 1 comprising 10 wt % Alusol 41 BF metalworking lubricant (available from Castrol Limited) and 90 wt % water.

[0032] Initial examination of Sample 1 and Sample 2 revealed that virtually no foaming was observed on mixing the NanoGel CCT with water. The samples then underwent several tests to determine their overall suitability for use in industrial fluids.

Tapping Torque

[0033] A tapping torque test under ASTM 5619-00 (2011) was carried out to compare Sample 1, Sample 2 and the Control Sample 1. This test determines the amount of torque required to form a thread in a pre-drilled hole in an aluminium alloy (AlZnMgCu0.5). Results were as in Table 2, taking the performance of the Control Sample 1 as a performance index of 100:

TABLE-US-00002 TABLE 2 Tapping Torque Test Sample Control Sample 1 Sample 1 Sample 2 Performance Index 100 93.5 99.4
As can be seen, the inclusion of 5 wt % of NanoGel CCT in water offers a small reduction in torque compared with the Control Sample. However, the inclusion of 10 wt % in water offers a significant reduction in torque compared with the Control Sample.

Corrosion Inhibition

[0034] The ability of Sample 1 to inhibit corrosion was also investigated, following measurement of the pH of the emulsion of approximately pH 5 (slightly acidic). A standard corrosion inhibition test (immersion of cast iron chips in Sample 2 and then reviewed for staining on filter paper by the iron chips as in DIN 51360 (part 2)) was carried out. On immersion, the cast iron chips began to corrode, but after approximately 15 minutes the corrosion process slowed significantly, leading to a measure of corrosion inhibition. In order to determine whether this was a chemical (composition) or a physical (micelle) process within the NanoGel CCT, the constituent components of NanoGel CCT were mixed as Control Sample 2, and the test repeated. Interestingly the corrosion process continued as normal throughout the immersion of the cast iron chips, indicating that the micelle structure of the NanoGel CCT gave improved corrosion inhibition compared with not using a micelle physical structure within the emulsion.

[0035] The above examples involve the use of normal-phase micelles, that is, where the surfactant forms a surface layer where the hydrophilic heads of the surfactant molecules face outwards; forming an oil-in-water mixture (the oleaginous component is in emulsion in the aqueous component). However, it may be desirable to use an inverse-phase micelle structure, forming a water-in-oil mixture (the aqueous component is in emulsion in the oleaginous component).

[0036] One further advantage of using the micelle structure in an industrial fluid as outlined above is that a precise range of micelle sizes can be achieved. The distribution of the average diameters of the micelles preferably follows a Gaussian profile, with a mean and a standard deviation . It is particularly advantageous for the standard deviation u to be less than or equal to 0.2. For example, for a mean average micelle diameter of 0.3 m, the standard deviation of the average micelle diameter is 0.06 m or less. The average micelle diameter is an average of various diameter measurements taken for a micelle, which in the case of spherical micelles is approximately equal to the micelle diameter (since there is little or no variation of the diameter regardless of where the measurement is taken). Preferably the average micelle diameter is 0.3 m. Suitable measurement techniques to determine both the average micelle diameter and the distribution of average micelle diameters include, but are not limited to, optical measurement techniquesfor example, laser particle size analysis using a Beckman Coulter Laser Diffraction PS Analyzer (LS 13 320), and flow cytometry techniques. The advantage of having a narrow range of average micelle diameters lies in the ability of the metalworking fluid to cover a surface fully. In a fluid where there is a wide range of average micelle diameters the coverage of the fluid across a surface is variable. This is due to regions of equal surface area having different volumes of fluid on them. However, if the average micelle diameter is in a small range the surface coverage is far more efficient and extensive, since regions of equal surface area will have approximately equal volumes of fluid on them. This leads to more even wear and improved surface/interface protection.

[0037] The viscosity index (VI) of various base oils stocks is given in Table 1 above. However, the kinematic viscosity of an oil base stock will also have an effect on whether or not the oil can be emulsified to create an aqueous emulsion. Typically oils suitable for use in the industrial fluids described above will have a kinematic viscosity of less than or equal to 20 cst at 40 C. However, oils may also be used having a higher kinematic viscosity than this, for example, up to 100 cst at 40 C.

[0038] The use of micelles in oleaginous and aqueous emulsions to form lubricating fluids finds use in many applications. For example, in addition to the metalworking fluids described above, such fluids may be used in an automotive application (including but not limited to engine or gearbox/drivetrain lubrication), an industrial process (including but not limited to gear lubrication, cutting applications, power generation and machinery lubrication) or a marine or subsea process (lubrication of drilling and cutting tools). Although the above examples illustrate a particular category of industrial fluids, other categories may also be based upon the emulsion/colloid system described above. Industrial fluids include lubricating, energy dissipating, energy generating, or energy transmission fluids and additives thereof. Energy dissipating fluids may include cooling fluids (such as drilling fluids used in subsea and terrestrial applications and industrial coolants), and energy generating fluids may include, but not be limited to fuels such as gasoline, diesel and kerosene. Energy transmission fluids include hydraulic and transformer fluids. Furthermore the industrial fluid may also find used as an additive to any of these fluids, in a similar manner to which additives are included in automotive lubricants and fuels. Such additives improve the performance, lifetime or operation of such fluids.

[0039] Various embodiments and other examples of industrial fluids will be apparent to the skilled person based upon the appended claims.