TW202340438A - Water based semi-synthetic metal working fluid composition containing a cyclic polyfunctional amine - Google Patents

Abstract

The present invention describes a water based semi-synthetic metal working fluid comprising a base oil, an organic acid, emulsifiers, a concentrate additive, water and a microbial growth control agent which comprises a cyclic polyfunctional amine.

Description

Water-based semi-synthetic metalworking fluid composition containing cyclic polyfunctional amines

The present invention relates to a method of controlling microbial growth in metalworking fluids, which comprises adding a specific class of cyclic polyfunctional amines to the metalworking fluid. Other embodiments are directed to semisynthetic metalworking fluid compositions that include microbial growth control agents that include this particular class of cyclic polyfunctional amines.

Metalworking fluids (MWF) are used for lubrication in metal cutting and tool forming. These fluids provide cooling for metalworking tools, remove cutting debris from the tool/workpiece interface and help provide an acceptable machined finished surface. Amines are common MWF components used in a variety of applications due to their anti-corrosion, neutralizing, and pH-adjusting properties. Organic amines are commonly used as corrosion inhibitors because MWF degrades over time due to the growth of microorganisms, which can negatively impact fluid performance and feed on active ingredients in the fluid.

Such microbial growth in MWF can cause serious problems in metal processing in many forms, including: overall acidification of MWF, changes in MWF viscosity, shortened MWF storage life, and corrosion of tools and materials. In addition, the functionality of equipment and processes such as feed nozzles, storage tanks, piping and recirculation system facilities may also be affected by microbial growth in MWF. This acidification will increase the cost of MWF, accelerate the corrosion rate and reduce the efficiency of metal processing. Therefore, there is an unmet need in the MWF industry for components that do not support microbial growth and maintain performance over time.

Therefore, there is an unmet need in the MWF industry for components that do not support microbial growth and maintain performance over time. The most common solution is to add biocides and amine alcohols to a given MWF either continuously or in a batch process. However, biocides and some secondary amine alcohols are subject to regulatory controls, and most biocidal chemicals will release formaldehyde over time, which is harmful to human health.

Existing MWFs are generally classified as pure oil, soluble oil, semi-synthetic fluid, or synthetic fluid, each of which exhibits different functions of cooling, lubrication, rust prevention, and cleaning. Soluble oil MWF contains 50-70 wt.% neat oil, with the remainder of the MWF being anti-wear/extreme pressure additives and emulsifiers. Neat and soluble oils generally do not provide the same degree of cooling as water-based metalworking fluids. Synthetic fluids generally do not provide good lubricity properties because their lubrication function is affected by reverse dissolution of the polyalkylene glycol that occurs at temperatures above the cloud point. Semi-synthetic materials offer the possibility of providing both good lubricity and cooling for applications where this is required. A typical semi-synthetic flow system consists of oil, organic acids, emulsifiers, lubricants, amines, water and other ingredients. In such semi-synthetic MWF, the amount of water is generally up to 50-60 wt.%, with about 10-40 wt.% base oil, about 10-20 wt.% emulsifier, about 10-20 wt.% amine , and other functional additives, such as acids, lubricants, solubilizers, biocides, etc. Semi-synthetic MWF is typically diluted with additional water at the end user's site to a base oil concentration of 1-20 wt.%, more typically 5-7 wt.%, based on the weight of the diluted formulation. concentration.

In semi-synthetic fluids, emulsifiers are often added to form stable oil-in-water dispersions. Emulsifier particles are positioned around the oil droplets to give the particles a negative charge, allowing them to bind to water molecules. The size of such emulsified oil droplets is extremely important to fluid performance because it is generally easier for smaller emulsion sizes to penetrate the interface of the cutting zone. Emulsifiers also contribute to the stability of semi-synthetic fluids.

Semi-synthetic fluids will degrade over time, in part due to the growth of microorganisms that negatively impact fluid performance as they feed on the active ingredients in the fluid. Such microbial growth in MWF can cause serious problems in metal processing in many forms, including: overall acidification of MWF, changes in MWF viscosity, shortened MWF storage life, and corrosion of tools and materials. In addition, the functionality of equipment and processes such as feed nozzles, storage tanks, piping and recirculation system facilities may also be affected by microbial growth in MWF. This acidification will increase the cost of MWF, accelerate the corrosion rate and reduce the efficiency of metal processing. The most common solution to control microbial growth is the addition of biocides and amine alcohols to a given MWF either continuously or in a batch process. However, biocides and some secondary amine alcohols are subject to regulatory controls, and most biocidal chemicals will release formaldehyde over time, which is harmful to human health.

Accordingly, there is a need for new semi-synthetic metalworking formulations with new biocide compositions that provide improved cooling, lubricity, concentration stability, and long shelf life without the environmental conditions posed by current fluids Health and Safety Issues.

The present invention addresses at least some of the above needs.

The present invention relates to a method of controlling microbial growth in a metalworking fluid, wherein the method includes adding at least one of a specific class of cyclic polyfunctional amines to the metalworking fluid. The present invention also describes a water-based semi-synthetic metalworking fluid that includes a base oil, an organic acid, an emulsifier, a concentrated additive, water, and a microbial growth control agent including a novel cyclic polyfunctional amine.

Depending on the composition, metalworking fluids are classified as neat oils, soluble oils, semi-synthetic fluids, or synthetic fluids. Soluble oil MWF contains 50-70 wt.% oil, with the remainder being anti-wear/extreme pressure additives and emulsifiers. Semi-synthetic MWF contains large amounts of water, typically up to 50-60 wt.%. Semi-synthetic fluids have balanced lubricity and cooling properties and are therefore attractive for use as MWFs.

This invention relates to semi-synthetic metalworking fluids and new materials useful as antimicrobial agents for use in such fluids. The materials of the present invention are cyclic polyfunctional amines corresponding to the following formula (I): Formula (I) wherein each R, T, U, V, W, X, Y and Z group in the above formula (I) are independently selected from hydrogen or hydrocarbon groups; and the value of x is 0 to 10. Hydrocarbyl groups useful in the practice of this invention may be substituted (generally substituted with N, O, or S atoms) or unsubstituted, linear, branched, or cyclic hydrocarbyl groups, such as alkyl, aryl, aralkyl , or similar groups; monovalent moieties, including one or more heteroatoms; polyether chains containing one or more oxyalkylene repeating units (such as -R ₁ O-), where R ₁ is 2 to 5 carbons Alkylene group of atoms; other oligomers or polymer chains of at least 2 repeating units. In one embodiment, R, T, U, V, W, X, Y, and Z are H or linear, branched or cyclic hydrocarbon groups, such as 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms. Alkyl groups such as methyl or ethyl. In another embodiment, R, T, U, V, W, X, Y, and Z are H. In the practice of the present invention, the value of x is usually in the range of 1 to 10, preferably in the range of 2 to 5, more preferably in the range of 2 to 3 and most preferably in the range of 0-1.

Such cyclic polyamines are commercially available or are produced by transamination of cyclic amines as is generally known in the art. Examples of high molecular weight, cyclic polyamines conforming to the above formula (I) suitable for use in the present invention include bis(2-(piperidine-1-yl)ethyl)amine (BPEA), (3-(piperidine-1-yl)ethyl)amine (BPEA), (3-(piperidine-1-yl)ethyl)amine, 1-yl)propyl)amine, bis(4-(piperidine-1-yl)butyl)amine, bis(5-(piperidine-1-yl)pentyl)amine, bis(6-(piperidine-1-yl)butyl)amine -1-yl)hexyl)amine, bis(1-(piperidine-1-yl)propan-2-yl)amine, bis(2-(piperidine-1-yl)propyl)amine, and mixtures thereof.

A preferred embodiment of the cyclic polyamine compound suitable for preparing the composition of the present invention includes, for example, bis(2-(piperidine-1-yl)ethyl)amine (BPEA); high molecular weight BPEA oligomers; and its mixture. The MWF of the present invention includes water, one or more base oils, one or more organic acids, one or more emulsifiers, one or more lubricants, and one or more amines, wherein the amines serve as pH regulators and/or microbial growth control agents. function, wherein at least one amine contains at least a cyclic polyamine of formula (I).

The microbial growth control agent may further comprise one or more additional antimicrobial materials, such as glycol ether amines, which may be used in combination with the materials disclosed above to achieve certain microbial growth control objectives. The concentration of microbial growth control agent/pH adjuster in MWF (including cyclic polyamines of formula (I)) may range from 1, 4, 6, 8, or 10 percent up to 30% by weight of the formulation. , 25, 15, or 12 percent. Preferably, the cyclic polyamine of formula (I) accounts for 2, preferably 3, or even 5 percent up to 25, preferably 20, or even 15 percent by weight of MWF.

The semi-synthetic MWF of the present invention also includes base oil. The base oil can be any base oil commonly known in the art for use in MWF. Preferably, the base oil is a base oil selected from pine oil, naphthenic oil, paraffin-based oil, or ester oil, or a combination thereof. The concentration of base oil in MWF can range from 5, 7, 10, or 15 percent by weight of the formulation up to 50, 45, 40, or 35 percent of the formulation.

The water used in the formulations of the present invention is preferably deionized water and may account for at least 20, preferably 25, 30, or even 35 percent up to 70, 65, or even 35 percent by weight of the formulation. 60, 55, or even 50 percent. It is anticipated that such formulations may be further diluted with additional water prior to use, thus altering these ranges accordingly. For example, prior to use, such formulations may be diluted such that the base oil concentration is 1 to 20 percent, more typically 5 to 7 weight percent, based on the weight of the diluted formulation.

The semi-synthetic MWF of the present invention also includes one or more organic acids as solubilizers and/or corrosion inhibitors. Preferred organic acids include 2-ethylhexanoic acid, azelaic acid, pine oil fatty acid, 12-hydroxy-(cis)-9-octadecenoic acid, dicarboxylic acid, and 9-octadecenoic acid. The concentration of organic acid in MWF can range from 2, 3, 4, or 5 percent by weight of the formulation up to 12, 10, 8, or 7 percent of the formulation.

The semi-synthetic MWF of the present invention also includes one or more emulsifiers. Emulsifiers can be anionic, cationic, or nonionic. Examples of suitable anionic surfactants or emulsifiers are alkali metal, ammonium and amine soaps; the fatty acid portion of such soaps preferably contains at least 10 carbon atoms. Soaps can also be formed "in situ"; that is, fatty acids can be added to the oil phase and alkaline materials can be added to the water phase.

Other examples of suitable anionic surfactants or emulsifiers are alkali metal salts of alkyl-arylsulfonic acids, sodium dialkylsulfosuccinates, sulfated or sulfonated oils (eg sulfated castor oil); sulfonates Beef tallow, and alkali metal salts of short-chain petroleum sulfonic acids.

Suitable cationic surfactants or emulsifiers are salts of long-chain primary, secondary or tertiary amines, such as oleylamide acetate, acetamide acetate, behenylamine lactate, aminoethyl-aminoethyl Acetate salts of stearylamine, dilauryl triethylenetetramine diacetate, 1-aminoethyl-2-heptadecenyl imidazoline acetate; and quaternary salts such as cetylpyridinium bromide onium, cetylethylmorpholinium chloride, and diethyl bis-dodecyl ammonium chloride.

Examples of suitable nonionic surfactants or emulsifiers are the condensation products of higher fatty alcohols and ethylene oxide, such as the reaction products of oleyl alcohol and 10 ethylene oxide units; the condensation products of alkylphenols and ethylene oxide. Products, such as the reaction product of isooctyl phenol with 12 ethylene oxide units; the condensation product of higher fatty acid amide with 5 or more ethylene oxide units; polyethylene glycol esters of long-chain fatty acids, such as tetrahydrofuran Ethylene glycol monopalmitate, hexaethylene glycol monolaurate, nonaethylene glycol monostearate, nonaethylene glycol dioleate, 13ethylene glycol monoarachidate, 23 ethylene glycol Glycol monobehenate, triethylene glycol dibehenate, polyol higher fatty acid esters such as sorbitan tristearate, polyol higher fatty acid esters and their internal anhydrides (mannan Ethylene oxide condensation products of sugar alcohol-anhydride, known as mannitol anhydride, and sorbitol-anhydride, known as sorbitan anhydride), such as glycerol monopalmitate reacted with 10 ethylene oxide molecules, Neopenterythritol monooleate reacted with 12 ethylene oxide molecules, sorbitan monostearate reacted with 10-15 ethylene oxide molecules, and 10-15 ethylene oxide molecules Reacted mannitol anhydride monopalmitate; long-chain polyethylene glycol in which one hydroxyl group is esterified with a higher fatty acid and the other hydroxyl group is etherified with a low molecular weight alcohol, such as methoxypolyethylene glycol 550 monostearic acid Ester (550 means the average molecular weight of polyglycol ether). Combinations of two or more of these surfactants may be used; for example, cationic and nonionic may be blended or anionic and nonionic may be blended.

Particularly suitable emulsifiers include C16-18 alcohols which have been ethoxylated or propoxylated; ethoxylated C12-C15 alcohols; sodium alkane sulfonates and alkyl ether carboxylates.

The concentration of emulsifier in MWF can range from 4, 5, 6, 8, or 10 percent up to 25, 20, 15, or 12 percent by weight of the formulation.

The semi-synthetic MWF of the present invention may also include one or more concentrated additives. When present, preferred concentrated additives include diethylene glycol butyl ether, ethylene glycol monobutyl ether, and propylene glycol butyl ether. If present, the concentration of concentrated additives in the MWF may range from 0.3, 0.5, 1.0, or 1.5 percent by weight of the formulation up to 2.5, 2.0, or 1.8 percent by weight of the formulation.

The semi-synthetic MWF of the present invention may also include other additives to provide additional functions, as is generally known in the art.

Microbial growth controlled by the biocides disclosed herein generally consists of contamination by a mixture of bacteria and fungi. Some typical fungal and bacterial containments include, but are not limited to, Aeromonas hydrophila (ATCC 13444), Candida albicans (ATCC 752), Desulfovibrio desulfuricans (ATCC 7757), Escherichia coli (ATCC 8739), Flavobacterium ferrugineum (ATCC 13524), Fusarium oxysporum (ATCC 7601), Klebsiella pneumoniae ) (ATCC 13883), Proteus mirabilis (ATCC 4675), Pseudomonas aeruginosa (ATCC 8689), Pseudomonas oleovorans (ATCC 8062) and Saccharomyces cerevisiae 10 (ATTC 2338). The strains listed above may vary throughout the world, and the present innovation is fully contemplated as a broad spectrum microbial growth control agent and/or biocide that can be used against any common MWF microbial contaminant. Example

Experiments to test the efficacy of formulations including the microbial growth control agents disclosed herein can be conducted as follows. Table 1 contains a description of the materials used in these examples. Table 1 - Diluted Metalworking Fluid Composition Material Type Source mineral oil Oily agent SCRC EcoSurf SA-7 emulsifier Dow Dowfax 20A42 emulsifier Dow Secondary alkane sulfonate anionic surfactant SCRC Terpinenic acid corrosive agent SCRC sebacic acid corrosive agent SCRC Bis(piperethyl)amine pH regulator Dow Monoisopropanolamine pH regulator Dow AMP-95 (2-amino-2-methyl-1-propanol) pH regulator Angus Chem Processing water Water containing common bacterial agents found in metal processing processes N/A tap water Water containing 50 ppm metals N/A Aluminum Strip(#ADC12) metal TCI

A series of formulations were prepared according to Table 2, with the different amines listed in Table 3. Table 2 Material Concentrated formulation mineral oil 12.5wt.% EcoSurf SA-7 7.5wt.% Dowfax 20A42 5.5wt.% Secondary alkane sulfonate 4.5wt.% Terpinenic acid 4.5wt.% sebacic acid 4.5wt.% Amines (as indicated in Table 3) 10.7wt.% water 50.3wt.% table 3 Project Amine type Diluted water type Example 1 (IE1) Bis(piperethyl)amine Processing water Example 2 (IE2) Bis(piperethyl)amine tap water Example 3 (IE3) Bis(piperethyl)amine deionized water Comparative Example 1 (CE1) Monoisopropanolamine Processing water Comparative Example 2 (CE2) AMP-95 Processing water Comparative Example 3 (CE3) Dicyclohexylamine Processing water Comparative Example 4 (CE4) Monoisopropanolamine tap water Comparative Example 5 (CE5) AMP-95 tap water Comparative Example 6 (CE6) Dicyclohexylamine tap water Comparative Example 7 (CE7) Monoisopropanolamine deionized water

Concentrated formulations are prepared as follows. Pour the indicated amount of deionized water into the container. Add mineral oil, EcoSurf SA-7, Dowfax 20A42, secondary alkanesulfonate, terpineic acid, and diacid (sebacic acid) to the water. The formulation was stirred by magnetic stirrer at 200 rpm at 60°C for 1 hour. Add the indicated amine as pH adjuster.

The concentrated formulation is then diluted with process water or tap water or deionized water (as indicated in Table 3) by a dilution factor of 20 times based on the amount of the entire concentrated formulation. Test the pH with a pH titrator (Mettler Toledo: #SevenMulti). If the pH of the diluted formulation is below 9.5, introduce additional monoethanolamine (1-2 drops) to increase the pH to at least 9.5.

pH Aging Test: The pH of the prepared diluted formulations was tested with a pH titrator (Mettler Toledo: #SevenMulti) for days 0 and 14. Leave the sample at ambient temperature. Table 4 : pH Aging Test: Sample# Initial pH pH value at 1 week aging pH value at 2 weeks aging pH loss(%) IE1 9.54 9.43 9.43 - 1.2% CE1 9.55 8.72 8.52 - 10.8% CE2 9.54 9.29 9.29 - 2.6% CE3 9.63 9.33 9.30 - 3.4%

After 2 weeks of aging, the pH decrease should be as small as possible. IE1 with bis(piperethyl)amine, CE2 and 3 with AMP-95 and dicyclohexylamine showed similar levels of pH loss controlled within 5%. CE1 with monoisopropanolamine performed poorly, with a pH loss of over 10%.

Aluminum Corrosion Test: Clean Al tape (#ADC12) with alcohol and weigh the tape. The Al strip was immersed in the test solution at 40°C for 48 hours and the vial was capped (half the volume of the Al strip was in solution and half the volume of the Al strip was exposed to air). The corrosion of the Al strip surface was observed, the weight loss of the Al strip was measured and the Al content in the formulation was detected using ICP-OES: Inductively Coupled Plasma Optical Emission Spectrometer (Perkin Elmer: # Optima 5300DV). Table 5 : Aluminum Corrosion Test: Sample# Corrosion Aluminum content measured by ICP-OES IE2 pass through < 1 ppm CE4 pass through < 1ppm CE5 edge < 1ppm CE6 Fail 2.60ppm

The ICP-OES data show consistent results with qualitative observations of aluminum strip corrosion. Larger areas with a yellow color show severe corrosion and higher aluminum content in the test fluid. Add the qualitative description "pass," "marginal," or "fail" to comparatively describe the observed results. ICP-OES data shows that CE6 with dicyclohexylamine leaches out of its own packaging and corrodes more than 1 ppm of aluminum. Sample CE6 has the worst appearance and the largest rust area. For other samples including IE1, CE4 and 5, there was <1 ppm aluminum leaching from the tape.

pH value in case of antimicrobial testing: Samples were run under ASTM E 2275 method. This approach can be summarized as follows: The inoculum was a mixture of ATCC strains of bacteria and fungi as set forth in Table 6. Emulsion Products Mixed Inoculum was prepared by adding 0.1 mL of each bacterial overnight broth culture and 1.0 mL of each yeast broth culture to 10 mL of mold suspension and blending.

Feed 50 grams of sample with 0.5 ml of mixed inoculum. This inoculation will attack the emulsion sample with high levels of microorganisms (106-107 community forming units/gram of sample, CFU/g). Challenged samples were mixed and stored in an incubator at 30°C for seven days. For 5 additional rounds of testing, repeat this process by adding the following amounts of inoculum to each sample: 0.5 mL for round 2; 1.0 mL for round 3; 1.0 mL for round 4; and 3.0 mL for round 5. . The pH of the inoculated emulsion samples was tested at the end of the 5 week protocol and compared to the initial pH of the emulsion before the addition of the community. Table 6 microorganism ATCC number germ: Pseudomonas aeruginosa 10145 Pseudomonas putida 12633 Enterobacter aerogenes 13048 Alcaligenes faecalis _ 25094 Proteus hauseri 13315 Burkholderia cepacia 21809 Gluconacetobacter liquefaciens (Asai) 14835 Gluconobacter liquefaciens 23751 yeast: Saccharomyces cerevisiae 2338 Candida lipolytica 18942 Mold: Aspergillus niger 6275 Penicillium ludwigii 9112 Table 7 : Antimicrobial testing: Sample# Initial pH pH at 5 weeks in the presence of microorganisms IE3 9.82 9.70 CE7 9.76 9.46

IE3 with bis(piperethyl)amine showed only a pH reduction of 0.12 in the antimicrobial evaluation. CE7 with monoisopropanolamine showed a pH reduction of 0.30 in the antimicrobial evaluation. Therefore, IE3 is expected to have better microbiological stability than monoisopropanolamine when used in metalworking fluid formulations.

without

without

Claims (13)

A semi-synthetic metalworking fluid comprising: a. At least one base oil; b. At least one microbial growth control agent, the microbial growth control agent comprising an alkylamine having the following structure: wherein each R, T, U, V, W, X, Y and Z in the above formula (I) are independently selected from hydrogen or hydrocarbon groups; and the value of x is independently 0 to 10; c. One or more organic acid, d. one or more emulsifiers, e. one or more concentrated additives, and f. water. The semi-synthetic metalworking fluid of claim 1, wherein each of R, T, U, V, W, X, Y and Z in the microbial growth control agent is H. For example, the semi-synthetic metal working fluid of claim 1, wherein the microbial growth control agent is bis(2-(piperidine-1-yl)ethyl)amine (BPEA). The semi-synthetic metal working fluid of claim 1, wherein the microbial growth control agent further contains another amine. Such as the semi-synthetic metal working fluid of claim 1, wherein the base oil is selected from naphthenic base oil, paraffin base oil, ester oil, and mixtures thereof. The semi-synthetic metal working fluid of claim 1, wherein the emulsifier is selected from the group consisting of ethoxylated or propoxylated C16-18 alcohols, ethoxylated C12-C15 alcohols, sodium alkyl sulfonates, and Alkyl ether carboxylates, and mixtures thereof. Such as the semi-synthetic metal working fluid of claim 1, wherein the solubilizer/corrosion inhibitor is selected from the group consisting of ethylhexanoic acid, azelaic acid, pine oil fatty acid, 12-hydroxy-(cis)-9-octadecenoic acid, Dicarboxylic acid, 9-octadecenoic acid, sebacic acid, and mixtures thereof. Such as the semi-synthetic metal working fluid of claim 1, wherein the concentrated additive is selected from the group consisting of diethylene glycol butyl ether, ethylene glycol monobutyl ether, propylene glycol butyl ether, and mixtures thereof. The semi-synthetic metalworking fluid of claim 1, wherein the microbial growth control agent is present in an amount of 6 to 15% by weight of the semi-synthetic metalworking fluid. Such as the semi-synthetic metalworking fluid of claim 1, wherein the base oil is present in an amount of 10 to 45% by weight of the semi-synthetic metalworking fluid. The semi-synthetic metalworking fluid of claim 1, wherein the emulsifier is present in an amount of 5 to 20% by weight of the semi-synthetic metalworking fluid. The semi-synthetic metalworking fluid of claim 1, wherein the solubilizer/corrosion inhibitor is present in an amount of 3 to 10% by weight of the semi-synthetic metalworking fluid. The semi-synthetic metalworking fluid of claim 1, wherein the water is present in an amount of 20 to 60% by weight of the semi-synthetic metalworking fluid.