WO1993002164A1

WO1993002164A1 - Glycol/water microemulsion metalworking fluids

Info

Publication number: WO1993002164A1
Application number: PCT/US1992/004958
Authority: WO
Inventors: Philip R. Miller; Kevin M. Delaney; Michelle R. Wilson; Eugene F. Rothgery; Edward P. Bobby
Original assignee: Olin Corporation
Priority date: 1991-07-15
Filing date: 1992-06-12
Publication date: 1993-02-04
Also published as: AU2293292A

Abstract

The present invention relates to a microemulsion metalworking composition concentrate characterized by an aqueous continous phase and an organic dispersed phase comprising water insoluble polyalkylene glycol droplets having a submicron particle size. The concentrate consists essentially of water, an emulsifier which is a water-soluble, base-neutralized phosphate ester, and a water insoluble polyalkylene oxide alcohol. Also disclosed is the use of these concentrates, as is or upon further dilution with water, in a metalworking operation which comprises contacting a metal part to be machined or formed with a lubricating effective amount of the concentrate or water-diluted concentrate. Also disclosed is a mixture useful as an intermediate in the preparation of the above concentrate which consists essentially of the phosphate ester and the water insoluble polyalkylene oxide alcohol.

Description

GLYCOL/WATER MICROE ULSION METALWORKING FLUIDS

The present invention relates generally to glycol/water microemulsions and, more specifically, to oil-free, polyalkylene glycol/water microemulsions for use in metalworking fluids. The prior art is replete with lubricant- containing formulations useful as metalworking fluids, such as those used for machining and forming ferrous and non-ferrous metals. Typically, machining operations require ever increasing operating speeds in order to increase productivity. Such increasing demands require enhanced lubricant formulations and lubricant additives.

Environmental concerns are playing an increasingly significant role in the selection of new lubricant fluids. For example, when working with aqueous fluids, important considerations include the degree of removal of contaminants from the water phase of the fluid before waste disposal, and the treatability and environmental impact of any organics remaining in the water phase, as well as the ability to dispose of or re-cycle the materials removed from the waste-water stream. Three types of water dilutable lubricants are commonly used in the industry- today. The first two types are the so-called "soluble oil" and the "semi-synthetic" fluids, both of which typically contain naturally-occurring oils such as mineral oil, vegetable oil, and/or animal oil. For example, U.S. Patent 4,654,155 discloses a vegetable or animal oil-containing lubricant composition which also contains a phosphate ester, an amine, one or more polyol and/or polyalkylene glycol esters and a polyalkylene glycol polymer. Unfortunately, these hydrocarbon oil-containing lubricants are subject to a variety of problems during use, as well as disposal problems after use, due to the presence of the naturally-occurring oils therein. In some geographic regions, used oil is considered hazardous waste.

The third type of lubricant falls in the classification of the so-called "synthetic" fluid which is typically free of naturally-occurring oils. By way of illustration, Canadian Patent 1,082,679 discloses synthetic fluid lubricants in solution form and containing polyoxyalkylene glycols, phosphate esters, water-soluble amines, and water. Unfortunately, the use of water-soluble polyalkylene glycols, such as those disclosed in the working examples of this Canadian Patent, makes recovery of these glycols difficult since they are difficult to separate from water after use. Although these water-soluble polyalkylene glycols are moderately biodegradable and can be treated by municipal treatment plants, these plants are, in many locations, operating at or near capacity, typically causing increased treatment costs or even refusal to accept additional loading. Heretofore, a solution to the above-discussed problems has not been known based upon the knowledge of the present inventors. The present invention provides such a solution. In one aspect, the present invention relates to a microemulsion metalworking composition concentrate characterized by an aqueous continuous phase and an organic dispersed phase comprising water insoluble polyalkylene glycol droplets having a submicron particle size, said concentrate consisting essentially of: a) from about 25 to about 70 percent by weight of water based upon the weight of the concentrate; b) as an emulsifier, between about one and about 20 weight percent, based upon the weight of the concentrate, of a water-soluble, base-neutralized phosphate ester prepared by reacting a base with a phosphate ester in a molar ratio of base to phosphate ester of between about 1:1 and about 5:1, wherein the phosphate ester is the reaction product of phosphorous pentoxide and a polyalkylene oxide mono-ol in a molar ratio of polyalkylene oxide mono-ol to phosphorus pentoxide of between about 1.5:1 and about 3:1, said polyalkylene oxide mono-ol having the formula:

_Rl

where R is selected from the group consisting of saturated and unsaturated alkyl radicals having one to about twelve carbon atoms, aryl radicals and alkylaryl radicals wherein the alkyl substituent comprises from one to about nine carbon atoms and is saturated or unsaturated; and where R is selected from the group consisting of saturated and unsaturated alkyl radicals have one to about six carbon atoms; and where n is an integer from 10 to about 30 such that the average molecular weight of the mono functional polyalkylene glycol polymer ranges from about 900 to about 1800 (preferably between about 1000 and about 1500), said base being employed in an amount sufficient to adjust the pH of the concentrate from about 6 to about 11 and preferably being selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, and alkyl amine moieties and other amines, such as, for example, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, n-propylethanolamine, methyldiethanolamine, aminomethyl propanol and an amine selected from the group consisting of heterocyclic amines, including morpholine and its analogs; c) from about 1 to about 20 (preferably from about 5 to about 10) percent by weight, based on the weight of the concentrate, of a water insoluble polyalkylene oxide alcohol having a number average molecular weight of between about 750 and about 4,000 (preferably between about 900 and about 1,100). Below the lowest molecular weight of 750, the alcohols tend to be water soluble and thus do not form microemulsions, whereas above a molecular weight of 4,000, the compositions tend to separate out. In another aspect, the present invention relates to the use of the above concentrates, as is or upon further dilution with water, in a metalworking operation which comprises contacting a metal part to be machined or formed with a lubricating effective amount of the concentrate or water-diluted concentrate.

In still another aspect, the present invention relates to a mixture useful as an intermediate in the preparation of the above concentrate, said mixture consisting essentially of: a) a phosphate ester which is the reaction product of phosphorous pentoxide and a polyalkylene oxide mono-ol in a molar ratio of polyalkylene oxide mono-ol to phosphorus pentoxide of between about 1.5:1 and about 3:1, said polyalkylene oxide mono-ol having the formula:

R¹

I RO-( C H₂- C H-0)_n H

where R is selected from the group consisting of saturated and unsaturated alkyl radicals having one to about twelve carbon atoms, aryl radicals and alkylaryl radicals wherein the alkyl substituent comprises from one to about nine carbon atoms and is saturated or unsaturated; and where R is selected from the group consisting of saturated and unsaturated alkyl radicals have one to about six carbon atoms; and where n is an integer from 10 to about 30 such that the average molecular weight of the mono functional polyalkylene glycol polymer ranges from about 900 to about 1800 (preferably between about 1000 and about 1500), said base being employed in an amount sufficient to adjust the pH of the concentrate from about 6 to about 11 and being selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, and alkyl amine moieties and other amines, such as, for example, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanola ine, n-propylethanolamine, methyldiethanolamine, aminomethyl propanol and an amine selected from the group consisting of heterocyclic amines, including morpholine and its analogs; and b) a water insoluble polyalkylene oxide alcohol having a number average molecular weight of between about 750 and about 4,000 (preferably between about 900 and about 1,100), the molar ratio of said phosphate ester to said polyalkylene oxide alcohol in said mixture being between about 3:1 and about 1:3.

These and other aspects will become apparent upon reading the following detailed description of the invention.

In accordance with the present invention, it has now been surprisingly found that a metalworking fluid composition, in the form of a microemulsion, is provided having a dispersed phase that is easily split om water and provides excellent cooling and lubricity properties while being free of petroleum, animal and vegetable oils. The metalworking fluid comprises a water-insoluble polyalkylene oxide alcohol lubricant which is microemulsified with a water-soluble, base neutralized, phosphate ester emulsifier.

The polyalkylene oxide alcohols useful as the lubricant component of the present invention are generally prepared by anionic or cationic catalysis using, for example, an alkali metal salt of a lower alkanol initiator, as is well-known in the art. These polyalkylene oxide alcohol lubricants preferably have a cloud point of less than 50°F. An illustrative example is a potassium hydroxide catalyzed butanol initiated polypropylene glycol. Suitable lower alkanol initiators are selected from the group consisting of saturated and unsaturated alkyl radicals having from one to about twelve carbon atoms, preferably from one to about six carbon atoms, aryl radicals and alkylaryl radicals wherein the alkyl substituent comprises from one to about nine carbon atoms and is saturated or unsaturated, preferably wherein the alkyl substituent comprises from one to about four carbon atoms an is saturated. The various polyalkylene glycols, including mono-ols, diols, triols, and the like, are well known in the art and are commercially available, for example, under various trademarks, including Olin Corporation's POLY-G trademark. Union Carbide Corporation's UCON trademark, and BASF Corporation's PLURACOL trademark. Other useful lubricants include random and block copolymers of ethylene oxide and propylene oxide with the proviso that the cloud point, or inverse solubility temperature, is sufficiently low to separate from water. These polymers are well known in the art and are commercially available, for example, under Olin

Corporation's POLY-G and POLYTERGENT trademarks and BASF Corporation's PLURONIC trademark and Union Carbide Corporation's UCON trademark.

The phosphate ester emulsifier is prepared by reacting phosphorc s pentoxide with a polyalkylene oxide mono-ol in tne molar ratio range described above, followed by base neutralization. The phosphate esters are insoluble in water until being base neutralized by reaction with an alkali such as sodium hydroxide, potassium hydroxide, onoethanolamine, diethanolamine, triethanolamine, etc. This reaction can be performed, if desired, in situ when blending the metalworking fluid concentrate. Base neutralization is preferably effected to provide a pH of the metalworking composition concentrate of at least 7 or higher. Of great importance in forming a stable microemulsion is the selection of the appropriate combination of polyalkylene glycol lubricant and polyalkylene glycol phosphate ester emulsifier.

Other conventional metalworking fluid additives may be used so long as they do not adversely affect the emulsion stability or lubricity of the fluid. Such additives include corrosion inhibitors,extreme pressure additives, defoamers, biocides, fungicides, hydrotropes, chelating agents, colorants or dyes and pH buffering agents.

Examples of suitable corrosion inhibitors include, but are not limited to, amine carboxylates, amine borate esters, and combinations of these. Other suitable corrosion inhibitors would be obvious to one skilled in the art and are commercially available.

The amount of corrosion inhibitor is generally from about 1 part to about 20 parts by weight in the concentrate, depending on the effectiveness of the corrosion inhibitor selected and the dilution factor the concentrate is designed for.

Examples of suitable extreme pressure additives include, but are not limited to, chlorinated fatty acids,for example, Keil Corporation's CW-105A or other chlorine containing molecules; disodium dimercaptothiadiazole, for example, R.T. Vanderbilt Corporation's NATD or other sulfur containing compounds; and/or amine phosphates, for example. Mazer Chemical Inc.'s MAPHOS or other phosphorous containing additives. Other EP additives would be obvious to one skilled in the art.

Suitable defoamers may be used in the present invention. Such defoamers are generally proprietary products and/or blends of several components and are known only by their commercial trade names. Suitable, preferably organic and preferably non-dimethylsiloxane, defoamers for use in the present invention include Foam Ban MS products from Ultra Additives. Other suitable defoamers would be obvious to one skilled in the art.

The amount of defoamer in the concentrate is generally from about 0.25 to about 10 parts by weight, again dependant on its effectiveness and designed dilution factor.

Examples of biocides and fungicides include, but are not limited to, TRIADINE® 10 bactericide-fungicide, sodium OMADINE® bactericide-fungicide and TRIADINE® 3 bactericide all from Olin Corp. These have been found to be stable and efficacious in the concentrate of the present invention, but other additives can negatively affect stability and hence, stability on each formulation should always be evaluated. Other bactericides and fungicides suitable for use are obvious to one skilled in the art and are commercially available. Not all, however, are suitable for use in concentrates, but can still be added to the metalworking fluid tankside. Bactericide and fungicide usage should be consistent with EPA guidelines for the product selected.

Other conventional surfactants, hydrotropes and emulsifiers may be added so long as they do not adversely affect the properties of the emulsion. Suitable additives of this ty - would be obvious to one skilled in the art. EXAMPLE 1 Preparation of a Microemulsion Lubricant

116.53 grams of a 1040 molecular weight butanol initiated polypropylene glycol (mono-ol) (POLY-G®WI-285) was placed in a dry three neck flask under a nitrogen atmosphere. 5.46 grams of 97% phosphorous pentoxide was added over a period of ten minutes and a four degree temperature rise was observed. The mixture was then heated for a total of ten hours at 90°C. The product obtained was an amber viscous liquid.

Twelve parts of the product of the above . reaction was blended with ten parts triethanolamine, five parts of a 1040 molecular weight butanol initiated polypropylene glycol, and seventy three parts water. The resultant mixture was clear and amber colored. A dilution containing 10% of this blend in water was also clear, indicating that a microemulsion had been formed. After six months the solution was still clear, indicating the microemulsion was stable.

EXAMPLE 2

Preparation of Microemulsions Using an Alkylaryl

Initiated Polypropylene Glvcol Emulsifier

243.3 grams of a 811 molecular weight nonylphenol initiated polypropylene glycol (mono-ol) was placed in a dry, nitrogen padded three neck flask.

14.62 grams of 97% phosphorous pentoxide was added over a ten minute period. An exotherm of 5°C was noted. The mixture was heated for four hours at 90°C. Twelve parts of the product of the above reaction was blended with ten parts triethanolamine. five parts of a 1000 molecular weight polypropylene glycol, diol and seventy three parts water. The resultant mixture was clear and amber colored.

EXAMPLE 3 Preparation of Another Microemulsion Lubricant

37.5 grams of a 1040 molecular weight butanol initiated polypropylene glycol (POLY-G®WI-285) was placed in a dry three neck flask under a nitrogen atmosphere. This material was then heated to 50°C and 1.8 grams of 97% phosphorous pentoxide was added over a period of ten minutes with stirring resulting in a temperature rise to 65°C. The mixture was heated for a total of 150 minutes at 70°C. The product obtained was an amber viscous liquid. Twelve parts of the product of the above reaction was blended with ten parts triethanolamine, five parts of a 1040 molecular weight butanol initiated poly r.opylene glycol, and seventy three parts water. The resultant mixture was clear and amber colored. A dilution containing 10% of this blend in water was also clear, indicating that a microemulsion had been formed.

EXAMPLE 4 Using a Lower Molecular Weight Monol

225.0 grams of a 750 molecular weight butanol initiated polypropylene glycol (mono-ol)(POLY-G®WI-165) was placed in a dry, nitrogen padded three neck flask. 14.63 grams of 97% phosphorous pentoxide was added over a ten minute period. An exotherm of 14°C was noted. The mixture was heated for four hours at 90°C.

Twelve parts of the product of the above reaction was blended with ten parts triethanolamine, one part of a 1000 molecular weight polypropylene glycol, diol and seventy seven parts water. The resultant mixture was slightly hazy, but stable.

A diluted working fluid containing 10% of the above blend in water is also a microemulsion.

EXAMPLE 5

A pilot plant scale up was done using the following operating procedure:

Unit Consumptions:

POLY-G®WI-285 191.4 lbs.

P 0₅ 8.63 lbs.

Procedure:

1. To ensure that the reactor is completely dry, heat the vessel to 150°F and pull a full vacuum for 1 hour.

2. After 1 hour, cool the reactor by setting the tempered water to 100°F under a full vacuum.

Allow 1 hour for the reactor to cool.

3. Vacuum charge the reactor with 191.4 lbs. of WI-285 through the sample point. Break the vacuum with nitrogen. 4. Add a pre-weighed amount of ₂°5 ^{to tne} reactor after agitation has begun.

5. After addition of all reactants is complete, purge the reactor with nitrogen for 15 minutes and seal.

6. Set the temperature controller to cascade at 200°F. Once the reactor has reached temperature, post react for 4 hours.

7. When the acid number meets specification (50 mgKOH/gm max), cool to 130°F and filter the product through a 30 micron filter. 5 The resulting product was an amber colored viscous liquid. Stable microemulsions were found with up to 1000 MW mono-ol, up to 4000 molecular weight diols and up to 3000 molecular weight triols.

EXAMPLE 6

!0 pilot plant synthesis was done using the procedure as in Example 5, substituting POLY-G®WI-625 (an 1800 molecular weight butanol initiated polypropylene glycol), having the following unit consumptions:

15 POLY-G®WI-625 0.975 lbs.

P₂0₅ 0.025 lbs.

Stable microemulsions were formed with up to 750 MW mono-ol up to 4000 MW diol and up to 3000 MW triol.

0 EXAMPLE 7

The metalworking fluid of the present invention was evaluated for its anti-corrosion properties using the Standard Test Method for Iron Chip Corrosion for Water Soluble Metalworking Fluids (ASTM D4627-86) . 5 Briefly, this test is conducted by placing cast iron chips in a petri dish containing a filter paper and diluted metalworking fluid. The dish is covered and allowed to stand overnight. The amount of rust stain on the filter paper is an indication of the corrosion control provided by the fluid. The metalworking fluid concentrate is usually successively diluted to a point where rust does occur. Table I shows the results and comparative results utilizing the above described method:

Table i

Component Concentrate Formulation (Wt.%)

_B_ wi-285 Phosphate Ester

POLY-G WI-285

1000 MW Diol

TEA 99%

MEA ADDCO CP-502

HOSTACOR TP-2098

NASUL 412

Pelargonic Acid

ANTARA LK-500 EMULPHOR EL-620

PEG 600 Monooleate

UCON MLX-1281

Water

Results:

Dilution with Water

2% concentrate R R R NT % concentrate NR R NR NT % concentrate NR NR NR NT 03 concentrate NT NT NT R R-= Rust NR- No Rust NT» Not Tested

* Produced in accordance with U.S. Patent No. 4,654,155

EXAMPLE 8

The metalworking fluid of the present invention was evaluated for its waste treatment characteristics. An acid alum split procedure was used as follows:

1) Make up solutions containing 5000 ppm of solids content (approximately 1% by weight of the concentrate) with 110 ppm hardness water.

2) Add hydrochloric acid to a pH of 2.

3) Add 150 ppm of alum (1.0 ml. of 15,000 ppm solution) . 4) Transfer to a separatory funnel, let stand for 3 hours.

5) Drain off water layer (bottom phase) and analyze for total organic carbon (TOC) content. Results are shown in Table II below.

Table II

Component Concentrate Formulation (Wt )

Results

TOC, wt.% 0.14 0.16 0.12 0.28

It should be noted that ethanolamines, for example TEA, are not split from the water phase using the acid alum split. A fluid containing 15% TEA-99% would contribute 0.07% TOC to the final result. Many corrosion inhibitors also contain alkanolamines as well. Therefore formulations A,B and C, excluding the TEA, contribute only about 25% as much organic as D. Alkanolamines can be removed from the water phase using flocculants.

* Produced in accordance with U.S. Patent No. 4,654,155.

EXAMPLE 9

The metalworking fluid of the present invention ^• was evaluated for its lubrication properties using a tapping torque test machine. Briefly, this test measures the torque required to tap a thread in a blank specimen nut using various lubricants. Data is reported as an efficiency value of the test fluid relative to a reference oil (%Efficiency=torque of reference oil/torque of sample fluid X 100) . The reference oil consists of a mineral oil containing 5-6% by weight of lard oil and is run at 400 RPM to minimize tap wear. Specimen nuts can be of any metal and taps can be designed for cutting (metal removal) or forming (metal deformation) . Machining speed can also be varied. Several examples are shown in Table III below.

Results, % efficiency

2024A1,forming,1200RPM 208 211 NT NT NT

15 380Cast Al,cut,1200RPM NT NT 592 486 440

1215Steel,cut,1200RPM NT 291 289 NT NT

All results shown above were determined on 5% dilutions of the formulations.

Claims

WHAT IS CLAIMED IS:

1. A microemulsion metalworking composition concentrate characterized by an aqueous continuous phase and an organic dispersed phase comprising water insoluble polyalkylene glycol droplets having a submicron particle size, said concentrate consisting essentially of:

(a) from about 25 to about 70 percent by weight of water based upon the weight of the concentrate; (b) as an emulsifier, between about one and about 20 weight percent, based upon the weight of the concentrate, of a water-soluble, base-neutralized phosphate ester prepared by reacting a base with a phosphate ester in a molar ratio of base to phosphate ester of between about 1:1 and about 5:1, wherein the phosphate ester is the reaction product of phosphorous pentoxide and a polyalkylene oxide mono-ol in a molar ratio of polyalkylene oxide mono-ol to phosphorus pentoxide of between about 1.5:1 and about 3:1, said polyalkylene oxide mono-ol having the formula:

R¹

I RO-( C H₂- C H-0)_n H

where R is selected from the group consisting of saturated and unsaturated alkyl radicals having one to about twelve carbon atoms, aryl radicals and alkylaryl radicals wherein the alkyl substituent comprises from one to about nine carbon atoms and is saturated or unsaturated; and where R is selected from the group consisting of saturated and unsaturated alkyl radicals have one to about six carbon atoms; and where n is an integer from 10 to about 30 such that the average molecular weight of the mono functional polyalkylene glycol polymer ranges from about 900 to about 1800, said base being employed in an amount sufficient to adjust the pH of the concentrate to be between about about 6 and about 11; and (c) from about 1 to about 20 percent by weight, based on the weight of the concentrate, of a water insoluble polyalkylene oxide alcohol having a number average molecular weight of between about 750 and about 4,000.

2. The composition concentrate of claim 1 characterized in that the polyalkylene oxide mono-ol is the reaction product of propylene oxide and butanol.

3. The composition concentrate of claim 1 characterized in that component (c) is selected from the group consisting of butoxypolypropylene glycol having a number average molecular weight of between about 900 and about 1,100, polypropylene glycol diol having a number average molecular weight of between about 900 and about 1,100, and glycerine-initiated polypropylene glycol triol having a number average molecular weight of between about 1,300 and about 1,700, and combinations thereof.

4. The composition concentrate of claim 1 characterized in that said base is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, and organic amines, and combinations thereof.

5. A method of using the composition concentrate of claim 1 which is characterized by contacting a lubricating effective amount of said concentrate, alone or in admixture with water, with a metal part to be machined or formed.

6. A mixture useful as an intermediate in the preparation of a metalworking fluid concentrate, . said mixture consisting essentially of:

(a) a phosphate ester which is the reaction product of phosphorous pentoxide and a polyalkylene oxide mono-ol in a molar ratio of polyalkylene oxide mono-ol to phosphorus pentoxide of between about 1.5:1 and about 3:1, said polyalkylene oxide mono-ol having the formula:

R¹

I RO-( C H₂- C H-0)_n H

where R is selected from the group consisting of saturated and unsaturated alkyl radicals having one to about twelve carbon atoms, aryl radicals and alkylaryl radicals wherein the alkyl substituent comprises from one to about nine carbon atoms and is saturated or unsaturated; and where R is selected from the group consisting of saturated and unsaturated alkyl radicals have one to about six carbon atoms; and where n is an integer from 10 to about 30 such that the average molecular weight of the mono functional polyalkylene glycol polymer ranges from about 900 to about 1800; and,

(b) a water insoluble polyalkylene oxide alcohol having a number average molecular weight of between about 750 and about 4,000, the molar ratio of said phosphate ester to said polyalkylene oxide alcohol in said mixture being between about 3:1 and about 1:3.

AMENDED CLAIMS [received by the International Bureau on 8 December 1992 (08.12.92) original claims 1-6 deleted; new claims 7-18 added (7 pages)]

7. A microemulsion metalworking composition concentrate comprising an aqueous continuous phase and an organic dispersed phase comprising water insoluble polyalkylene glycol droplets having a submicron particle size, said concentrate consisting essentially of:

(a) from about 25 to about 70% by weight, based upon the weight of the concentrate, of water;

(b) from about 1 to about 20% by weight, based on the weight of the concentrate, of a water-soluble, base-neutralized phosphate ester emulsifier prepared by:

(i) forming a phosphate ester by reacting phosphorous pentoxide and a polyalkylene oxide mono-ol in a molar ratio of polyalkylene oxide mono-ol to phosphorus pentoxide of between about 1.5:1 and about 3:1, said polyalkylene oxide mono-ol having the formula:

Rl

I

RO-(CH₂-CH-0)_n-H where R is selected from the group consisting of saturated and unsaturated alkyl radicals having one to about twelve carbon atoms, aryl radicals and alkylaryl radicals wherein the alkyl substituent comprises from one to about nine carbon atoms and is saturated or unsaturated; and where R is selected from the group consisting of saturated and unsaturated alkyl radicals have one to about six carbon atoms; and where n is an integer from 10 to about 30 such that the average molecular weight of the poly¬ alkylene glycol mono-ol ranges from about 900 to about 1,800; and

(ii) then reacting said phosphate ester with a base to form a water-soluble, base-neutralized phosphate ester, the molar ratio of base to phosphate ester being between about 1:1 and about 5:1, and said base being employed in an amount sufficient to adjust the pH of the concentrate to be between about 6 and about 11; and (c) from about 1 to about 20% by weight, based on the weight of the concentrate, of a water-insoluble polyalkylene glycol having a number average molecular weight of between about 750 and about 4,000.

8. The composition concentrate of claim 7 wherein the polyalkylene oxide mono-ol is the reaction product of propylene oxide and butanol.

9. The composition concentrate of claim 7 wherein component (c) is selected from the group consisting of butoxypolypropylene glycol having a number average molecular weight of between about 900 and about 1 100, polypropylene glycol diol having a number average molecular weight of between about 900 and about 1,100, and glycerine-initiated poly¬ propylene glycol triol having a number average molecular weight of between about 1,300 and about 1,700, and combinations thereof.

10. The composition concentrate of claim 7 wherein said base is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, and organic amines, and combinations thereof.

11. A method of lubricating metal parts to be machined or formed during a metalworking operation comprising: (1) contacting said metal parts during said metalworking operation with a lubricating effective amount of a micro¬ emulsion metalworking composition concentrate, either alone or further diluted with water, said concentrate comprising an aqueous continuous phase and an organic dispersed phase comprising water insoluble polyalkylene glycol droplets having a submicron particle size, said concentrate consisting essentially of:

(a) from about 25 to about 70% by weight based upon the weight of the concentrate of water; (b) from about 1 to about 20 weight percent, based on the weight of the concentrate, of a water-soluble, base- neutralized phosphate ester emulsifier prepared by:

where R is selected from the group consisting of saturated and unsaturated alkyl radicals having one to about twelve carbon atoms, aryl radicals and alkylaryl radicals wherein the alkyl substituent comprises from one to about nine carbon atoms and is saturated or unsaturated; and where R is selected from the group consisting of saturated and unsaturated alkyl radicals have one to about six carbon atoms; and where n is an integer from 10 to about 30 such that the average molecular weight of the poly¬ alkylene glycol mono-ol ranges from about 900 to about 1,800; and (ii) then reacting said phosphate ester with a base to form a water-soluble, base-neutralized phosphate ester, the molar ratio of base to phosphate ester being between about 1:1 and about 5:1, and said base being employed in an amount sufficient to adjust the pH of the concentrate to be between about 6 and about 11; and (c) from about 1 to about 20% by weight, based on the weight of the concentrate, of a water-insoluble polyalkylene glycol having a number average molecular weight of between about 750 and about 4,000.

12. The method of claim 11 wherein the polyalkylene oxide mono-ol is the reaction product of propylene oxide and butanol.

13. The method of claim 11 wherein component (c) is selected from the group consisting of butoxypolypropylene glycol having a number average molecular weight of between about 900 and about 1,100, polypropylene glycol diol having a number average molecular weight of between about 900 and about 1,100, and glycerine-initiated polypropylene glycol triol having a number average molecular weight ^f between about 1,300 and about 1,700, and combinations thereof.

14. The method of claim 11 wherein said base is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, and organic amines, and combinations thereof.

15. A mixture useful as an intermediate in the preparation of a metalworking fluid concentrate, said mixture consisting essentially of:

where R is selected from the group consisting of saturated and unsaturated alkyl radicals having one to about twelve carbon atoms, aryl radicals and alkylaryl radicals wherein the alkyl substituent comprises from one to about nine carbon atoms and is saturated or unsaturated; and where R is selected from the group consisting of saturated and unsaturated alkyl radicals have one to about six carbon atoms; and where n is an integer from 10 to about 30 such that the average molecular weight of the mono functional polyalkylene glycol polymer ranges from about 900 to about 1800; and

(b) a water insoluble polyalkylene glycol having a number average molecular weight of between about 750 and about 4,000; the molar ratio of said phosphate ester to said polyalkylene glycol in said mixture being between about 3:1 and about 1:3.

16. The mixture of claim 15 wherein the polyalkylene oxide mono-ol is the reaction product of propylene oxide and butanol.

17. The mixture of claim 15 wherein component (b) is selected from the group consisting of butoxypolypropylene glycol having a number average molecular weight of between about 900 and about 1,100, polypropylene glycol diol having a number average molecular weight of between about 900 and about 1,100, and glycerine-initiated polypropylene glycol triol having a number average molecular weight of between about 1,300 and about 1,700, and combinations thereof.

18. The mixture of claim 15 wherein said base is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, and organic amines, and combinations thereof.