2. Description of the Prior Art Exhaust emission standards for engines, including internal combustion engines, combustion turbines, furnaces, steam boilers and the like, have become increasingly stringent in recent times. A known way of improving emissions is to use a mixture of fuel and water in the combustion chamber.

The water reduces peak combustion temperatures, which is believed to reduce NOx formation. Hydrocarbon and particulate emissions per unit of output power may also be reduced. Incorporation of water in fuel has been found to be particularly beneficial in diesel engines.

Water can be added to fuel as a water-in-fuel emulsion, or the emulsion may be used as the entire fuel. However, such emulsions tend to become unstable on storage, tending to separate into two layers over time. Various attempts have been made to improve the stability of water-in-fuel emulsions.

WO 03/016439 describes an emulsion fuel which is made by

combining filtered water with a middle distillate fuel along with an additional additive of water, ammonium hydroxide, a fatty acid mixture and a polyanhydride such as polyisobutylene succinic anhydride (PIBSA). For best results the water and fuel are first combined together and then mixed with PIBSA, ammonium hydroxide, and oleic acid.

WO 00/15740 describes a water-blended fuel composition which comprises (A) a hydrocarbon boiling in the gasoline or diesel range; (B) water; (C) a minor emulsifying amount of at least one fuel-soluble salt made by reacting (C) (I) at least one acylating agent having about 16 to 500 carbon atoms with (C) (II) ammonia and/or at least one amine; and (D) about 0.001 to about 15% by weight of the water- blended fuel composition of a water-soluble, ashless, halogen-, boron-, and phosphorus-free amine salt, distinct from component (C).

It is an object of the invention to provide a fuel emulsion composition which is relatively stable and low cost to manufacture.

SUMMARY OF THE INVENTION According to a first aspect of the present invention there is provided a method of manufacturing a fuel emulsion composition, the method comprising combining: (A) a hydrocarbon fuel phase having dissolved therein a fuel-soluble surfactant having at least one hydrocarbyl substituent of molecular weight (Mn) at least 500 and at least one hydrophilic moiety having acidic or

basic functionality; and (B) an aqueous solution phase of a water-soluble acid or base selected such that it is complementary to the functionality of the hydrophilic moiety of the fuel- soluble surfactant; and mixing the two phases sufficiently to create an emulsion having a hydrocarbon fuel continuous phase and an aqueous disperse phase.

We have found that by selecting a suitable aqueous acid or base, the method permits the manufacture of water-in-fuel emulsions of high stability. In a preferred embodiment, thermodynamically stable microemulsions may be formed.

The composition may optionally further comprise one or more additives, including any or all of: at least one organic cetane improver, an antifreeze, and an alcohol.

The fuel emulsion compositions may be burned in suitable combustion apparatus. Suitable apparatus includes, but is not limited to, external combustion burners, such as those used in oil fired central heating, internal combustion engines, and jet engines.

The term"complementary"is used herein to denote that the acid or base in the aqueous phase is selected so as to tend to neutralise the acidic or basic functionality of the hydrophilic moieties of the surfactant. Thus if the surfactant has acidic moieties, for example carboxylic acid groups, or reactive equivalents thereof, the aqueous phase will contain a basic material, for example an amine,

ammonia, or an alkali metal hydroxide. If the surfactant has basic moieties, for example amine functionality or a reactive equivalent, the aqueous phase will contain an acidic material, for example formic acid or 2-choloracetic acid.

The phrase"acidic or basic functionality"is used herein to denote that the fuel-soluble surfactant carries at least one moiety which has either acid functionality (for example a carboxylic acid group or reactive equivalent thereof) or basic functionality (for example amine functionality, which may be primary, secondary or tertiary). In a preferred embodiment, the surfactant carries a plurality of such moieties. In this case, it is preferred that all of the hydrophilic moieties are of one type (either all acidic or all basic). However, minor quantities of the opposite type may be present provided that the surfactant is sufficiently soluble in the fuel phase. The surfactant will therefore either carry an overall charge (notably when emulsified) or will carry one or more moieties which are capable of becoming charged under the reaction conditions (through dissociation or protonation) to give the surfactant molecule an overall charge.

The phrase"reactive equivalent"of a material is used herein to denote any compound or composition, other than the material itself, which reacts or behaves like the material under the reaction conditions. Thus, reactive equivalents of a carboxylic acid include acid-producing derivatives such as anhydrides, acyl halides, and mixtures

thereof. Reference herein to any material shall include reactive equivalents of that material unless explicitly stated otherwise.

The term"hydrocarbyl substituent"or"hydrocarbyl group" is used in its ordinary sense, well known to those skilled in the art. It refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Non-limiting examples of hydrocarbyl groups are given in WO 00/15740, pages 5-6, the contents of which are incorporated herein by reference. The term"hydrocarbylene group"refers to a divalent analog of a hydrocarbyl group.

The term"hydrocarbon fuel"is used herein to refer to hydrocarbonaceous petroleum distillate fuels (for example petrol (gasoline), diesel, and gas oil) and mixtures thereof. The term also refers to non-hydrocarbonaceous materials that include but are not limited to oils, fuels derived from vegetables (for example olive, corn, rapeseed, alfalfa), fuels derived from animal material (for example tallow), fuels derived from minerals (for example from shale, coal, anthracite and the like) and mixtures thereof and combinations thereof. The hydrocarbon fuel may include mixtures of one or more hydrocarbonaceous and one or more non-hydrocarbonaceous materials, for example diesel and corn oil. The hydrocarbon fuel may optionally be admixed with other additives, for example ethanol, acetone or ether.

The term"fuel soluble"means materials that are soluble

in the hydrocarbon fuel to the extent of at least one gram per 100 millilitres of fuel at 25°C. It also refers to materials that end up mostly in the fuel phase when a mixture of the material and equal volumes of fuel and water are mixed together, leaving the water phase substantially (greater than 90%) free of the material.

The term"water soluble"refers to materials that are soluble in water to the extent of at least one gram per 100 millilitres of water at 25°C.

"Molecular weight (Mn) "is used herein to refer to the number average molecular weight of the hydrocarbyl chain.

This number is based on the molecular weight of atoms which are part of the hydrocarbyl chain, but not of atoms in side groups or branches. For example, if all hydrocarbyl chains were 42 carbon atoms long, Mn would be 42 x 12 = 504. Because the surfactant has either acidic or basic functionality, one way of assessing Mn is by suitable titration by a method well known to those skilled in the art. For example, polyhydroxystearic acid may be titrated against KOH solution.

The term"biomass pyrolysis product"is used herein to refer to the product obtained when organic materials, for example straw, pulped willow, or sugar cane stalks, is heated to about 450°C to 600°C in the partial absence of air, and the resulting organic vapours are condensed. The process is described in Bridgwater A. V. , 1999"An Introduction to Fast Pyrolysis of Biomass for Fuels and Chemicals"in"Fast Pyrolysis of Biomass : a Handbook"

(edited by Bridgwater et al), CPL Press, UK, 1-13, the contents of which are incorporated herein by reference.

The product is a red-brown liquid consisting of a single phase polar solution of chemicals including up to 30% water. The biomass degradation products in solution include acetic and formic acids. Typical physical properties are: Viscosity 25-1000 cP pH 2-4 Density 1110-1250 gl~l The product typically contains lignin-derived materials and other surface-active agents. Most biomass pyrolysis products are corrosive and do not burn well. However, by incorporating them in an emulsion in accordance with the invention they may be burned for power generation in an environmentally acceptable manner. The biomass pyrolysis product may be used without modification to form the emulsion, or it may optionally be diluted with water and/or treated with additives known in the art per se to modify the properties of the resulting emulsion. Biomass products are considered"carbon-neutral"in that C02 released during combustion has been recently fixed from the atmosphere. Substitution of petroleum-derived fuels by biomass-derived fuels thus reduces the contribution to global warming from energy production.

The term"polyelectrolyte"refers to a substance that contains polyions, which are macromolecules bearing a large number of ionisable groups. The ionisable groups

are located at different points along the chain of the macromolecule. Typically, the polyelectrolyte is a polymer having regular repeat units, each of which includes one of the hydrophilic moieties. The hydrophilic moieties may be attached as pendant groups, for example carboxylic acid groups, or they may form part of the chain of the macromolecule, for example a secondary or tertiary amine group. Non-limiting examples of polyelectrolytes are given in the Kirk-Othmer concise encyclopaedia of chemical technology, 3rd edition, page 923, the content of which is incorporated herein by reference.

The aqueous disperse phase is predominantly composed of water and the dissolved acid or base. It may optionally include surfactants, and inorganic salts, for example sodium chloride. Other optional components include antifreezing additives, such as ethylene glycol, and other combustible organic compounds, such as ethanol. It may include combustible organic compounds derived from synthetic sources, or renewable sources, such as fermentation.

The additives of the invention may be used in combination with one or more co-additives known in the art, for example the following : detergents, antioxidants, corrosion inhibitors, dehazers, demulsifiers, metal deactivators, antifoaming agents, cetane improvers, co- solvents, fuel borne catalysts, package compatibilisers, middle distillate cold flow improvers, lubricity additives, static dissipators, stabilisers, biocides, re- odorants, dyes and markers.

The term"middle distillate cold flow improversN compri5es the following: wax anti-settling additives (WASA), wax anti-settling flow improvers (WAFI), pour point depressants (PPD), cloud point depressants (CPD) and cold filter plugging point additives (CFPP).

Without wishing to be bound by theory, it is believed that key features of the fuel phase soluble surfactant are: i) One or more fuel soluble polymer chains of molecular weight (Mn) at least 500. We believe that chains of at least this length, and solubility in the fuel phase, provide an effective steric stabilisation barrier between emulsion droplets, which have adsorbed the surfactant at the fuel/water interface.

This is achieved when, at the approach of two such droplets, the intercalation of the polymer chains is so unfavourable as to prevent the droplets contacting to coalesce. The polymer chains may be composed of a single monomer type, for example 12-hydroxystearic acid, or of a mixture of monomers. The chain length of the stabilising polymer chains, and their monomer composition, may be determined by experiment, for example by synthesising surfactants with a variety of chain lengths and monomer compositions, and measuring the stability of emulsions formed using them, or they may be derived from theoretical considerations. ii) One or more hydrophilic moieties, preferably located towards or at one end of the surfactant, these moieties

being of at least one species which, under appropriate conditions, dissociates or protonates to form charged species. They may be, for example, carboxylic acid groups. These moieties may either exhibit basic or acidic functionality. According to a preferred aspect of the present invention all hydrophilic moieties of t- :, he fuel phase soluble surfactant exhibit either basic or acidic functionality exclusively.

The water-soluble acid or base alters the pH of the aqueous phase, such that it is complementary to the ionised state of the hydrophilic moieties of the fuel phase soluble surfactant. According to the present invention, for example, chloroacetic acid may be selected as the water-soluble acid, where primary amine groups comprise the hydrophilic moieties of the fuel soluble surfactant. The water-soluble acid or base may be polymeric, for example polyacrylic acid.

The emulsion fuel compositions of the present invention show great stability to coalescence over time. Without wishing to be bound by this theory, it is believed that this stability derives from the dissociation of the hydrophilic moieties of the fuel phase surfactant, at the fuel water interface, creating an adsorbed surfactant species with charged groups. The fuel phase soluble surfactant molecules are oriented at the interface with the hydrophilic moieties towards the aqueous phase, and with the hydrophobic fuel soluble polymer chains oriented away from the aqueous phase. Surfactant molecules so oriented at the oil/water interfaces of emulsions are in

dynamic equilibrium with surfactant molecules in solution in the continuous phase. It is believed that the equilibrium for the charged surfactant species created-by dissociation strongly favours the species remaining adsorbed at the interface, maintaining the coherence of the steric stabilisation barrier.

Any upper limit for Mn of the hydrocarbyl substituent is practical rather than critical. Providing that the surfactant is sufficiently soluble in the fuel, and does not cause viscosity of the fuel emulsion to be unacceptable for its intended end use, Mn may be of any value over 500. For example Mn may be up to 1,000, 000.

Preferred ranges for the hydrocarbyl substituent are 500 to 10,000, notably 500 to 3,000. In one preferred embodiment, the hydrocarbyl chain has Mn in the range 1,000 to 2,500. In another preferred embodiment the hydrocarbyl chain is polyhydroxystearic acid prepared from commercial 12-hydroxystearic acid, which may contain minor amounts of oleic and stearic acids, and has a molecular weight (Mn) of about 1,600.

Where the hydrophilic moieties are provided by a polyelectrolyte the molecular weight (Mn) of the polyelectrolyte chain is preferably between 100 and 100,000, preferably between 200 and 10,000.

It is preferred that the droplet size of the disperse phase is below 5 ym. However, the lower size limit is not critical; for microemulsions, the droplet size may be as small as a few nanometres, for example 5 nm. More

typically, the droplet size will be as small as about 0.1 jim Another aspect of the invention provides a fuel emulsion composition obtainable by the method, in which a plurality of hydrophilic moieties are provided on a polyelectrolyte linked to the hydrocarbyl substituent.

Other aspects and benefits of the invention will appear in the following specification and claims.

DETAILED DESCRIPTION Manufacture of fuel emulsion compositions of the current invention is illustrated by reference to the following examples.

Example 1 The fuel emulsion of this example is formulated as: Unleaded petrol 78. 8% Water 20. 0% Sodium hydroxide 0. 2% Solsperse 3000 1. 0% (Solsperse is a trade mark of Avecia Ltd, Blackley, Manchester, England) In this example, Solsperse 3000, an acid functional polymeric dispersing agent having a hydrocarbyl group comprising poly (12-hydroxystearic acid) of Mn greater than 500, is used as the fuel phase soluble surfactant. The aqueous phase base is sodium hydroxide. The continuous fuel phase is formed by unleaded petrol.

The composition was manufactured by dissolving the Solsperse 3000 in the unleaded petrol, using a mechanical stirrer. In a separate vessel, the sodium hydroxide was dissolved in the water. Pouring the sodium hydroxide solution into the vessel containing the unleaded petrol and Solsperse 3000 then mixed the two liquids, while

stirring continued. An emulsion, which was milky in appearance, was instantly formed, in which the unleaded petrol formed a continuous phase, and the sodium hydroxide solution the disperse phase.

Transferring to a high shear mixer, and agitating for two hours further processed the emulsion fuel composition. The resulting emulsion was a white in colour, and showed no sign of separation on standing.

The emulsion fuel was combustion tested as the fuel source for an Austin Rover Mini Metro Vanden Plas, registration C648 XCG. The engine was started normally, and was run for several minutes, with the vehicle stationary.

The composition provided in Example 1 was stable on storage at room temperature for a period of one year: there was no apparent tendency for the disperse phase droplets to coalesce and separate the composition into two unmixed layers. Samples in sealed 15 ml glass vials were placed, for 24 hours, in a domestic freezer, (Bosch Duo System, barcode 3833 13227053) set to its coldest setting.

When returned to room temperature the sample showed no sign of separation. Further samples were placed in a water bath at or near boiling for one hour. The samples showed no sign of separation. A sample was subjected to freeze/ thaw cycling consisting of three alternate cycles each of 30 minutes freezing (as above), and heating (as above).

The sample showed no sign of separation.

The use of high shear mixing equipment causes the size of

the disperse phase droplets to be reduced. Smaller droplets have the benefit of a reduced tendency to settle to the bottom of the composition, and so help to keep the emulsion fuel homogenous over time. Suitable high shear mixing equipment includes, but is not limited to, rotor/ stator mixers, of the type manufactured by Silverson Machines Ltd of England, and beadmills, for example the K60, manufactured by Buhler AG. Other devices, such as microfluidzers, may also be used. Ultrasonic methods may also be employed.

In a preferred embodiment of the present invention, 90% of the droplets of the aqueous disperse phase are less than 5 Am in diameter, more preferably, 90% are less than 3 Am in diameter. According to one preferred embodiment of the present invention 90% of the droplets of the aqueous disperse phase are less than 1 Am in diameter. In another preferred embodiment, 90 % of the aqueous disperse phase droplets are less than 0.5 Am in diameter. It is preferred that the disperse phase droplets have a narrow size distribution. In one embodiment of the present invention a thermodynamically stable microemulsion is formed.

The size distribution of the aqueous disperse phase droplets may be examined by optical microscopy, or by light scattering methods, for example laser scattering in the Mastersizer, manufactured by Malvern instruments.

Example 2 Fuel phase soluble surfactant synthesis: i) Synthesis of polyhydroxystearic acid (PHSA) 724.8 g 12-hydroxystearic acid and 75.2 g of xylene were charged into a one litre vessel fitted with overhead stirrer, thermometer, nitrogen inlet and Dean and Stark apparatus. The mixture was heated with stirring to 215°C for 12 hours with nitrogen surface flow. The product was isolated by bubbling nitrogen through the mixture at 180°C. ii) Synthesis of surfactant 300 g of PHSA (above) and 30 g of polyethyleneimine (Epomin SP200) and 50 g of xylene were charged into a 500 ml vessel fitted with overhead stirrer, thermometer and nitrogen inlet. The mixture was heated with stirring to 130°C for 1.5 hours with nitrogen surface flow. This is an example of a surfactant in which the hydrophilic moieties are provided by a polyelectrolyte, in this example a polyelectrolyte with a plurality of amine functional groups. Formulations of the emulsions (parts by weight) are given in Table 1. Component Emulsion 2A Emulsion 2B Biodiesel blend 158 159 Surfactant 2 1 Citric acid 4 4 Water 36 36

Table 1 The surfactant was dissolved in the biodiesel blend and the citric acid was dissolved in the water. The two phases were combined and mixed before further processing through an Avestin high pressure homogeniser.

Emulsions were examined at 100x magnification using an oil immersion lens. All were mobile deflocculate dispersions.

Particle size data (ym, Table 2) were obtained before and after storage for 8 days at 60°C using dynamic light scattering. Emulsion 8 days 60°C 2A Mean = 0. 54 2B Mean = 0.70 Table 2 Microemulsions In the following examples the hydrophilic moieties are polyelectrolytes. The water soluble acids are contained

in the pyrolysis product. Example 4 demonstrates the formation of microemulsion where both phases are renewable products.

Example 3-Pyrolysis product in Gas oil Surfactant 1. 5% 0.30g Pyrolysis product 10. 0% 2. 00g Gas oil 88. 5% 17.70g The surfactant was dissolved in the gas oil by gentle stirring, and the pyrolysis product was added by pipette.

The mixture was shaken by hand. Microscopy at x1000 oil immersion showed spontaneous formation of a microemulsion.

Particle size analysis after 21 weeks storage at room temperature: Mean 0.178 microns S. D 0.086 microns Mode 0.141 microns Measurements were made with a Horiba LB 500 dynamic light scattering instrument.

Fuel phase soluble surfactant synthesis (for Example 3): i) Synthesis of polyhydroxystearic acid (PHSA) 724.8 g of 12-hydroxy stearic acid and 75.2 g of xylene were charged into a one litre vessel fitted with overhead

stirrer, thermometer, nitrogen inlet and Dean and stark apparatus. The mixture was heated with stirring to 2s5°C for 6.5 hours with nitrogen surface flow. 33.9 g of water was evolved. The product was isolated by bubbLing nitrogen through the mixture at 180°C. ii) Synthesis of surfactant 400 g of PHSA (above) and 100 g of polyethyleneimine (BASF Lupasol FG 800 mw) and 50 g of xylene were charged into a one litre vessel fitted with overhead stirrer, thermometer, nitrogen inlet and Dean and Stark apparatus.

The mixture was heated with stirring to 200°C for 3.5 hours with nitrogen surface flow. 11.94 g of water was evolved. The product was isolated by bubbling nitrogen through the mixture at 180°C. The surfactant comprises a hydrocarbyl substituent (PHSA) of Mn > 500, linked to a polyelectrolyte (polyethyleneimine) by an amide linkage from reaction of the carboxylic acid on the PHSA with an amine on the polyethyleneimine. The polyamine functionality of the polyethyleneimine makes the surfactant basic.

Example 4-Pyrolysis product in Tallow Surfactant 4.03 % 153.08g Pyrolysis product 20.15 % 765. 40g Tallow 75.82 % 2880. OOg The surfactant was dissolved in tallow at 60°C with high

shear mixing. The pyrolysis product was added v. ith stirring. Microscopy at x1000 oil immersion showed spontaneous formation of a microemulsion.

Particle size analysis (60°C) after 15 weeks storage at room temperature: Mean 0.147 microns S. D 0.034 microns Mode 0.143 microns Measurements were made with a Horiba LB 500 dynamic light scattering instrument The fuel phase surfactant from Example 2 was used.

Further Examples 1) Hydrolysis of PIBSA 1961.4 g 2300 Mw PIBSA (59% active) was charged to a round bottom flask fitted with a stirrer, nitrogen inlet, temperature probe and heating mantle. The temperature was raised to 45°C and 38.6 g of water was added over a ten minute period. The mixture was heated to 90°C for two hours with stirring and nitrogen surface flow.

2) DEEA Solution 23.8 g of diethyl ethanolamine was mixed with 1976.2 g of water to give a clear solution of 1. 19% DEEA in water.

3) Preparation of oleyl amide solution.

47.08 g of oleic acid and 100 g of polyethyleneimine (Epomin SP006,600 Mw) were charged into a round bottom flask fitted with overhead stirrer, nitrogen inlet, temperature probe and Dean and Stark apparatus with condenser. 40 g of xylene was added and the mixture refluxed for six hours between 136°C and 145°C with a nitrogen surface flow. The xylene was stripped out using nitrogen flow and subsequent vacuum distillation while the product was still warm. On cooling a clear liquid product was obtained.

1 g of product was dissolved in water to give a 1% solution.

4) Definition of components Biodiesel blend is a 95: 5 blend of diesel with methyl ester of rapeseed oil. _ PIBSA is 2300 Mw 59% active as above.

2-EHN is 2-ethylhexylnitrate.

DEEA is diethyl ethanolamine.

Emulsion compositions are given in Table 3. Component Emulsion Emulsion Emulsion Emulsion Emulsion Emulsion A B C D E F Diesel 156. 34 156. 30 156. 34 Gas-oil 155. 52 Biodiesel 156. 34 blend Jet-A 156. 34 Kerosene Hydrolysed 2. 0 1. 0 1. 0 1. 0 1. 0 PIBSA PIBSA 1. 0 Oleic acid 2. 0 1. 0 1. 0 1. 0 1. 0 1. 0 2-EHN 1. 42 1. 42 1. 42 1. 42 1. 42 1, 2 0. 24 0. 24 0. 24 0. 24 0.24 propanediol Oleyl amide 0.04 solution DEEA 40 40 40 40 40 40 Solution DEEA 0. 48

Table 3 5) Method for examples Emulsion A was made by mixing hydrolysed PIBSA oleic acid, 2-EHN, propanediol and diesel to form the fuel phase, with DEEA solution +excess DEEA forming the aqueous phase. In all the other examples hydrolyse PIBSA or PIBSA + were mixed with 2-EHN, propanediol and fuel to form fuel phase.

Oleic acid, oleyl amide solution were mixed with the DEEA solution to form the aqueous phase. This was added to the fuel phase and the two were mixed using an Ystral homogeniser. In all cases a milky white emulsion was

formed. Microscopy showed all were deflocculate mobile dispersions with extensive Brownian motion.

6) Initial particle size data Particle size data for selected emulsions were obtained using an Horiba LB500 dynamic light scattering instrument, and are given in Table 4. All measurements were made at 25°C. Emulsion Mean (m) S. D. B 0. 54 0. 19 C 0. 49 0. 2 D 0. 48 0. 18 E 0. 58 0. 16 F 0. 43 0. 24 Table 4 7) Room temperature storage data Emulsions A and B were stored in glass jars and examined for separation and sedimentation. After 7 days, surface separation of clear fuel was negligible. Emulsion A had a faint layer of sediment which comprised 1. 6% of the sample volume. Emulsion B was slightly more opaque at the base than the bulk sample but a layer of sediment was not defined.

8) 24 hour storage at 60°C particle size data Samples of emulsions were stored in glass jars for 24 hours at 60°C. Particle size data for selected emulsions were obtained using an Horiba LB500 dynamic light scattering instrument, and are given in Table 5. All measurements were made at 25°C. Emulsion Mean (ym) S. D. B 0. 53 0. 14 C 0. 56 0. 22 D 0. 84 0. 62 E 0. 53 0. 20 F 0. 45 0. 25 Table 5 9) Heavy fuel oil example 159 g of heavy fuel oil and 1 g of polyisobutenyl succinic anhydride (82% active, 950 Mw) were blended using an Ystral homgeniser to create a fuel phase and the temperature raised to about 50°C. An aqueous phase was prepared by diluting 5.88 g of ammonia solution (0.25% strength) with 34.12 g of water. The aqueous phase was added to the fuel phase while mixing. The emulsion formed was examined using a 1000x oil immersion lens and found to be deflocculate with dispersed water droplets ranging from about 1 to 5 Am in diameter, with the bulk of droplets in the range 1 to 3 Am.

While the present invention has been described with reference to specific examples, it should be understood that modifications and variations of the invention may be constructed without departing from the scope of the invention defined in the following claims.