US3161486A - Antistatic additives and their preparation - Google Patents

Description

United States Patent 3,161,486 ANTESTATIQJ ADDlTlVES AND THEIR PREPARATIQN Dilworth T. Rogers, Summit, and John P. McDermoti,

Springfield, N.J., assignors to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed May 18, 1961, Ser. No. 110,898 '17 Claims. (C1. 44-51) The instant invention concerns a process for treating antistatic additives to enhance their ability to promote electrical conductivity. In particular, this invention relates to a method of concentrating the colloidal fractions of antistatic additives in a liquid disperse system to obtain the more active antistatic fractions and compositions containing these fractions. This application is a continuationin-part of Serial No. 784,087, filed December 31, 1958, now Patent No. 2,992,909, and Serial No. 9,690, filed February 19, 1960, now Patent No. 3,084,038.

The generation, accumulation, and retention of excessive electrical charges during the processing, handling, storage, and transportation of combustible organic fluids have been a potential and suspected source of many explosions and fires. Particularly hazardous in this respect are combustible organic liquids boiling between 75 F. and 750 F., such as hydrocarbon oils and petroleum distillate fuels and organic volatile liquids preferably containing not more than an average of 12 carbon atoms per molecule, since with these liquids the danger of ignition or explosion occurring as a result of electrical charges is particularly great. Hazardous operations are not restricted to volatile liquids, but may also occur when, for example, a fluid product having a tendency to generate, accumulate, or store electrical charges is pumped or discharged into a tank or storage area containing a combustile vapor. In order to reduce the hazards of ignition and explosions, various antistatic additives have been incorporated in fluid products and particularly in these combustible organic liquids in minor amounts suflicient to increase the electrical conductivity of these liquids usually to greater than 1x10 mhos per centimeter. These additives are normally employed in minor amounts or in concentrations of from 1.0 to about 0.00001%- by weight and preferably from about 0.1 or even 0.05 to 0.000l% by weight.

Some of the additives suggested to increase the electrical conductivity when employed in amounts suflicient to promote electrical conductivity in many cases adversely affect the Water tolerance, thermal stability and other characteristic properties of the organic liquid, such as aviation turbojet fuels in which they are incorporated. Additionally, certain ash-forming metallic additives are particularly disadvantageous when utilized in certain fuels where the amount of ash formation is required to be at an absolute minimum, e.g., in the operation of a turbojet engine. It is, therefore, an object of this invention to describe a process of treating antistatic additives to enhance their electrical conductivity effects when incorporated in organic-liquids. A further object is to provide a method of concentrating the more active colloidal fraction of antistatic additives for subsequent incorporation in hydrocarbon oils. An additional object is to disclose a method of segregating the active fraction of metallic antistatic additives so as to reduce the amount of additive required for antistatic protection in jet engine fuels and thus reduce ash formation during the operation of jet engines on this fuel. I

It has been discovered that the colloidal fraction of antimoting electrical conductivity than the noncolloidal fraction of these additives. When a colloidal system containing a disperse phase of an antistatic additive in a dispersion 8,161,486 Patented Dec. 15, 1964 tion or all of the colloidal fraction, the more antistaticv active portion of the additive may be obtained. The colloidal fraction obtained may then be employed at a lower concentration level in combustible organic liquids or hydrocarbon oils to yield the desired electrical conductivity previously only obtained by higher concentrations of the total colloidal and noncolloidal fractions. The numerous advantages and beneficial results of treating combustible organic liquids or concentrates containing antistatic additives, or combinations thereof with other ingredients, or the antistatic additives themselves, to obtain the active colloidal fraction or to increase the concentration level of the active colloidal fraction above that of the original concentration is apparent to those skilled in the art.

The additives which may be dialyzed or otherwise treated to increase the concentration of the colloidal fraction and obtain enhanced electrical conductivity characteristics are impossible to divide on the basis of individual compounds, generic groups and substances, since the distinctions between colloidal substances and crystalloidal substances are not rigid (Textbook of Physical Chemistry, 2nd edition, Glasstone, page 1231). The colloidal systems with which the present invention is concerned include those systems wherein the dispersion medium is an organic liquid and wherein the antistatic additive comprises a noncolloidal and a colloidal fraction or forms a colloidal and a noncolloidal fraction in said liquid. These colloidal fractions are in general made up of submicroscopic particles having an average particle'diameter of less than 1 micron, for example, average diameters ranging between 0.001 micron and 1 micron, i.e., 10- and 10" centimeters, and preferably between 0.2 micron and 0.005 micron. In general, the nature of the particular substance employed is not of primary importance, for example, whether metallic or nonmetallic. importance with metal or ash-forming compounds since concentration of the active portion will reduce the amount of possible ash deposits in jet engine operation.

Suitable additives which benefit from the present discovery include: the organic soaps of polyvalent metals, such as the fatty acid metals; Group VI metals like chromium; Group III metals like aluminum; transition metals like cobalt, iron, nickel, and the like; the antistatic first and second additives disclosed in British Patent 749,898, published June 6, 1956, for example, the metal salts of alkylated salicyclic acids, such as chromic diiso'p ropyl salicylate, and combinations thereof. Particularly enhanced by the complexes disclosed in the parent applications, such as the chromium, aluminum, iron, cobalt, nickel complexes and the like. These metal complexes are prepared by reacting the'aliphatic C C monocarboxylic acid metal salt, e.g., chromium acetate, with a high molecular weight monocarboxylic acid, e.g., oleic acid, or with an alkyl phenol sulfide, e.g.,'dodecyl phenol sulfide, to yield complexes which form a collidal system in organic liquids,

e.g., isooctane.

The method discovered by the applicants is not restricted to metallic additive compounds, but includes Of course, this method will be of.

salts of the alkali or alkaline earth nonmetallic antistatic compounds such as the amine salts of fatty acids, like guanidine tallate, as described in US. application 16,966, filed March 23, 1960, now Patent No. 3,062,630; alkyl hydroxy aromatic sulfide; alkylated phenol sulfides, like dodecyl phenol sulfide; quaternary ammonium compounds, like tetraaliphatic quaternary ammonium additives like dimethyldialkyl ammonium chlorides, di-dimethyldioleyl ammonium phytate, as described in US. application 783, 187, filed December 29, 1958, now abandoned, tetraisoamyl ammonium picrate and the like, and combinations thereof. Other antistatic additives include lecithin, alkaloids, amines such as betaine alkanol amines, asphaltenes, alkali and alkaline earth petroleum sulfonates, amine and ammonium and quaternary ammonium salts of dialkyl phosphoric acid, P 8 treated hydrocarbons such as the barium salt of P 5 treated polyisobutylene and the like, and other additives such as those described in US. application 695,469, filed November 8, 1957, now abandoned, and in US. Patents 2,951,751, issued September 6, 1960, and 2,974,027, issued March 7, 1961. As is apparent, the applicants invention is not dependent upon the particular additive compound, but may be beneficially employed with all additives that enhance electrical conductivity and which are subject to separation into two fractions, e.g., a dialyzable and undialyzable fraction.

Normally, the colloidal or undialyzable fractions of these antistatic additives, for example, the metallic complexes, range from 1 to about 60% by weight of the total complex, but may be as high as 99.5 wt. percent and as low as 0.5 wt. percent for nonmetallic additives. The colloidal fraction is more effective than the total complex employed at similar concentration levels and many be from to 100 times more effective than the noncolloidal or dialyzable fraction. This represents a significant unexpected improvement in electrical conductivity.

The organic liquids in which the antistatic additives are employed to promote electrical conductivity and which may also form the dispersion medium of the colloidal systems or be the dialyzing liquid are organic liquids and preferably hydrocarbon oils boiling in the range between 75 F. and 750 F. Examples of organic liquids are aliphatic hydrocarbons or mixtures thereof, such as hexane, heptane, isooctane, petroleum naphtha, andgasoline; aromatic hydrocarbons or mixtures thereof, such as benzene, toluene and the xylenes; cycloaliphatic hydrocarbons, such as deealin; mixtures of various aliphatic, cycloaliphatic and aromatic hydrocarbons; halog enated hydrocarbons or mixtures thereof, such as chloroform, carbon tetrachloride, trichloroethylene, bromobenzene, and tetrachloroethylene and ethers, such as diethyl ether and dioxane; and other liquids such as carbon disulfide, synthetic ester lubricating oils, natural oils derived from animal, vegetable or marine sources.

The process is particularly useful where the recovered active fraction is to be incorporated in gasoline, aviation turbojet fuel, kerosene, diesel fuel, lubricating oils, greases, asphalt, waxes, cutting oils, fuel oils and other petroleum distillate fuels and products. Gasoline include both motor gasolines and aviation gasolines such as those defined by AST-M Specifications D9l057-T and D-439-58T. Aviation turbojet fuels are described in length in US. Military Specifications MIL-F-25524A, MIL-F-5624D, MILF25558B, and MILF25656(1), and in ASTM Specifications for Aviation Turbine Fuels D-1655-59T. Diesel fuels and fuel oils as referred to in connection with the invention are defined in ASTM Specifications D97559T and D39648T.

The treatment of the liquid colloidal system containing the antistatic additive may be accomplished in a liquid concentrate containing a'major portion of the additive agent, e.g., from 50 to 75 or 95 wt. percent, or on the additive without liquid diluent. The dialysis medium can be any liquid, such as water or aqueous solution;

but organic liquids, for example, as previously described, in which the additive material forms a dialyzable or colloidal fraction, are preferred. Thus, the dialysis liquid may be a substituted or nonsubstituted, saturated or unsaturated normally liquid aliphatic, alicyclic, alkyl, alkylene, alkyne, aromatic, alkylaryl, an arene, such as an alcohol, an aldehyde, an ester, a ketone, an ether, a hydrocarbon and the like or a combination of these liquids. The best liquid medium to use will depend in part on the additive to be employed, the amount of colloidal fraction formed in a particular liquid, the nature of the liquid, the end use of the additive, and other factors within selection of the chemist. It has been found that it is best to employ as the liquid dialysis medium a similar liquid in which the undialyzable fraction is subsequently employed. For example, where the process is employed to concentrate an additive for subsequent incorporation into a substantially liquid parafiinic jet fuel like LIP-4, it is preferred to employ a dialyzing liquid of similar chemical structure and characteristics, such as a hydrocarbon oil like isooctane or JP-4. Thus, for employment of the additives in distillate petroleum products, a liquid hydrocarbon medium should be used such as a saturated C C hydrocarbon like isooctane, hexane, heptane, or a paraffinic hydrocarbon mixture having a boiling point range of from to 450 R, such as gasoline, JP4, and the like. After dialysis or comparable treatment, the active colloidal fraction may be incorporated directly into the desired combustible organic liquid or in an additive concentrate in combination with other additives conventionally employed in such liquids, such as rust inhibitors, antioxidants, dyes, dye stabilizers, detergents, polymeric dispersant s, surfactants, scavenging agents, antiknocks, and the like.

The concentration of the colloidal fraction may be accomplished by any means which permits the separation of the colloidal fraction of the antistatic colloidal system from the noncolloidal or molecular fraction. The most common methods employed depend upon the differences in diffusion characteristics between the larger colloidal particles which are retained by a semipermeable membrane and those molecular or crystalloid fractions which readily diffuse through the membrane. Thus, separation by dialysis is the most common and simplest method with the rate and method of dialysis being dependent on many factors, such as the area of the dialyzer, the membrane employed, the size of the pores, the temperature, the electrical charges, relative concentrations of the solution on either side of the membrane, and the like.

In the separation of fractions by diffusion methods, semipermeable membranes in the form of sacks, sausage skins, seamless thimbles, or the like may be employed. Suitable membranes includes various natural animal and artificial membranes which contain pores so that dissolved molecules and ions can pass through, but which retain the colloidal fractions. Some suitable mem branes include cellophane, collodion membranes, natural, synthetic and latex type rubbers, cellulose acetate, paper, plastic, and the like. Membrane selection must. also be based on considerations as to the effect of the dialysis liquid on the membrane. For example, an aromatic dialysis liquid like toluene with a, rubber membrane might initially be suitable, but in time changes in the pore size of the membrane beyond the critical limits desired might occur. Ordinarily, dialysis is a slow process, but the use of electrodialysis has facilitated the rate of separation. In this method, the colloidal solution is placed between the two dialyzing membranes with water or other liquid compartments containing electrodes on each side. The rapidremoval of charged particles is then accelerated by the use of an applied voltage, e.g.,

of from about 50 to 300 volts.

Separations may, also be accomplished by ultrafiltragrained tion means whereby the colloidal solution or system is filtered through a semipermeable membrane of specially treated filter paper or the like with the passage of the liquid dispersion medium accelerated by pressure or suction. Additional means include the use of ultracentrifuge methods whereby high speed, i.e., above 30,000 r.p.m., Svedberg ultracentrifuges allow the separation of the colloidal and noncolloidal fractions of a colloidal system.

Other means of treating the antistatic colloidal system to increase the amount of the active colloidal fraction include methods whereby one of the fractions is removed by precipitation, flocculation, or coagulation; the use of ion exchange resins; molecular sieves; sonic methods; and the like. Due to economy and simplicity, dialyzing means employing semipermeable membranes are preferred.

The exact nature and objects of the invention may be more fully understood by reference to the following examples.

EXAMPLE 1 Complexes were prepared by reacting chromic acetate with oleic acid and dodecyl phenol sulfide directly or in the presence of solvents at temperatures between about 180 F. and about 300 F. as follows:

A. A solution of 10.0 g. (0.018 mole) of dodecylphenol sulfide and 0.37 g. (0.0015 mole) of chromic acetate in 200 ml. of absolute ethanol was heated on a steam bath until all the alcohol was removed. A clear, dark, reddish-green viscous product was obtained.

B. A mixture of 10.0 g. (0.018 mole) of dodecylphenol sulfide and 0.37 g. (0.0015 mole) of chrornic acetate was stirred on a steam bath for 12 hours during which time the mixture gradually became clear. A dark, reddish-green viscous product was obtained.

Complexes were prepared by reacting chromic acetate and oleic acid as follows:

C. A solution of 2.47 grams of chromic acetate (0.01 mole) in 50 ml. of ethanol was added to a solution of 16.9 grams of oleic acid (0.06 mole) in 50 ml. of ethanol. The resulting solution was evaporated to dryness on the steam bath, whereupon 17.9 grams of a reddish-green, tacky solid were obtained.

EXAMPLE 2 The metallic antistatic complexes of Example 1 were then dialyzed to separate the colloidal and noncolloidal fractions of the complexes. Dialysis was accomplished by placing the antistatic metal complex in a finger-shaped, rubber, semipermeable membrane suspended in isooctane in a Soxhlet extractor and slowly refluxing to continuously extract the noncolloidal fraction I which passes through the membrane. The colloidal, or undialyzable, fraction II is retained within the rubber membrane finger. These fractions were then incorporated along with the total complex in various samples of JP-4 fuel and the electrical conductivity of the fuel determined to test the eifec'tiveness of the additive fractions in comparison with the total fraction. In this method the dialysisliquid is i-sooctane, While theadditive comprising a colloidal and noncolloidal fraction is being employed in concentrate form.

The fuel employed in carrying out these tests was representative of the aviation turbojet fuel classified as JP-4 fuel and defined by US. Military Specification MIL-F-5624D. It had an API gravity of 48.7 a Reid, vapor pressure of about 2.5 pounds per square inch and a boiling range between about 100 and about 500 F.

I Weight Specific Ratio, v Composition percent of Oonduc- (base) to Original tivity, 11 cr (base+ Additive (mho/cm additive) Base .TP-4 None 0. 04

Base JP-4:

Plus 0.002 wt. percent Additive A 100 5. 9 118 Plus 0.002 wt. percent Additive A, Fraction I 92 1.1 28 Plus 0.002 wt. percent Additive A, Fraction II 8 140 3, 500 Plus 0.002 wt. percent Additive B a. 100 5. 9 118 Plus 0.002 wt. percent Additive B, Fraction I 74 0.2 5 Plus 0.002 wt. percent Additive B, Fraction II 26 89 2, 235 .Plus 0.002 Wt. percent Additive O 100 45.3 1,510 Plus 0.002 wt. percent Additive 0, Fraction I 45 0.3 10 Plus 0.002 wt. percent Additive 0, Fraction II 53 287 9, 560

The tests werecarried out by applying a fixed, directcurrent voltage across a standard conductivity cell'containing the sample to be tested.- A standardhigh-resistance element was connected in series with the cell 1 and the current which flowed inthe circuit during the test was computed by measuring the voltage across the resistance element and applyingrO hmsvlaw. The resistance of the sample, the specific resistance and the specific conductivity were in turn computed. The results of these tests are shown below for the base fuel and for the samples of the base fuel containing the various additives.

Table I EFFECT OF DIALYSIS UPON THE SPECIFIC CONDUCTIVITY OF METALLIC ADDITIVES IN JP-4 Table II THE EFFECT OF ADDITIVE CONCENTRATION UPON THE CONDUCTIVITY OF JP-4 Specific Ratio, Condue- 0' (Base) to tivity, o", a (Base-{- mholoc r mx Additive) Concentration, Wt. Percent of Additive A, Fraction II None 0. O4 5. 0 21 530 sec 9, 000

The foregoing demonstrates that the colloidal fraction obtained by dialysis is extremely effective over a wide range of concentrations and yields conductivity results approximately proportional to the additive concentration employed.

EXAMPLE 4 v A further demonstration of the efficacy of the present process and its ability to concentratethe most effective and the active portion of both metallic and nonmetallic antistatic additives is shown by thefoll'owing data of Table III. I An aLkyl C -C hydroxyl aromatic sulfide, for example, an alkyl phenol sulfide, and a tetraaliphatic C C quaternary ammonium phyta-te Were'dialyzed'and tested.

phenol sulfide were dialyzed by placing these compounds in a natural rubber, finger-type membrane in a Soxhlet extraction apparatus and employing isooctane as the continuous liquid dialysis medium. The results of conductivity measurements were determined as before with the following results. Fraction I represents the dialyzed fraction, while Fraction II represents the undialyzable fraction retained by the membrane.

Table III EFFECT OF DIALYSIS UPON THE SPECIFIC CONDUC- TIVITY OF NONNIETALLIO ADDITIVES IN JI-4 The foregoing data indicate the broad value of the instant process to all antistatic additives. For example, dodecyl phenol sulfide was demonstrated to be a wholly ineffective additive to promote electrical conductivity. Upon. concentration of the active colloidal or undialyzable fraction of this additive, this fraction was very effective in en-- hancing the specific conductivity of JP-4. The two di-- verse nonmetallic additives, as shown above, allow sig-- nificant and unexpected enhancement of the electrical conductivity when Fraction II was incorporated into JP-4. It; should be noted that the effectiveness of the undialyzed fraction was not dependent on the amount dialyzed since in one case Fraction II constituted 0.5 wt. percent, while in the other Fraction II constituted 98.6 wt. percent of the total additive dialyzed.

EXAMPLE 5 tivity of the fuel more than a comparative concentration.

of the total additive.

EXAMPLE 6 An antistatic additive having unexpected electrical conductivity characteristics is obtained by incorporating about 10 to 50 wt. percent of chromium octyl salicylate in hexane to form a colloidal system, and subsequently dialysingsaid colloid-containing solution employing a cellulose containing, semipermeable membrane with hexane as the dialysis liquid. The solution fraction retained by the membrane when incorporated in carbon disulfide at a concentration level of about 0.01 wt. percent enhances the electrical conductivity of the fuel more than the comparative concentration of the total additive.

It is, of course, recognized and within the scope of the invention that the concentrated or active colloidal fractions obtained by the applicants process may be subsequently employed alone or in volatile organic and in aqueous solutions to treat the surface of various solid articles which have a tendency to accumulate, generate, orstore static charges. Thus, for example, the active colloidal fraction of tetraaliphatic ammonium pliytates such as di-dimethyldioleyh ammonium phytate may be utilized to treat the surfaces of articles such as vinyl-containing resins, synthetic textile fibers and yarns or films contain ing polyester resins, vinyl chloride, polyethylene, vinylidine chloride, cellulose, natural animal or vegetable fiberslike wool, cotton, natural and synthetic rubber and the like, and combinations thereof. Treatment of these surfaces to aid in dissipating the electrical charge that accumulates by frictional contact or movement may be accomplished by painting, spraying, dipping, impregnating, immersing, coating or otherwise placing the active fraction on the surface to be protected.

In summary, the applicants have discovered that the separation of the colloidal fraction of an antistatic additive produces a fraction which has enhanced ability to promote electrical conductivity. The instant discovery is not dependent upon the particular type of additive or upon the separating means employed, but rather on the discovery that a certain fraction, when separated from the total additive, has unexpected antistatic effectiveness.

What is claimed is:

l. A process for concentrating the active fraction of antistatic additives which additives form colloidal and noncolloidal fractions, said process comprising dialyzing said antistatic additive in order to effect at least partial separation of the noncolloidal fraction and then recovering the concentrated colloidal fraction, said concentrated fraction having an enhanced ability to promote electrical conductivity.

2. A highly effective antistatic composition consisting essentially of the concentrated colloidal fraction of an antistatic additive produced by the process of claim 1.

3. A highly effective antistatic composition consisting essentially of the concentrated colloidal fraction of an antistatic additive produced by the process of claim 1 wherein said antistatic additive is the reaction product of dodecylphenol sulfide and chromic acetate.

4. A highly effective antistatic composition consisting essentially of a concentrated colloidal fraction of an antistatic additive produced by the process of claim 1 wherein said antistatic additive is a chromium salicylate.

5. A highly effective antistatic composition consisting essentially of the concentrated colloidal fraction of an antistatic additive produced by the process of claim 1 wherein said antistatic additive is a quaternary ammonium compound.

6. A process as defined in claim 1 wherein said colloidal fraction is concentrated by dialysis means.

7. A process as defined by claim 1 wherein said colloidal fraction is concentrated by electro dialysis means.

8. A process as defined by claim 1 wherein said colloidal fraction is composed of colloidal particles having average diameters of less than 1 micron.

9. A hydrocarbon turbojet fuel boiling in the range of from F. to 750 F. to which has been added a minor amount sufiicent to promote the electrical conductivity of said fuel of a concentrated, colloidal fraction of a metallic antistatic additive produced by the process of claim 1.

10. A combustible organic liquid boiling in the range of from 75 to 750 F, said liquid containing a minor amount suiiicient to increase the electrical conductivity of said liquid to a value greater than l 10 mhos per centimeter of a concentrated colloidal fraction prepared by selecting an antistatic additive which additive comprises acolloidal fraction and a noncolloidal fraction; dialyzing said antistatic additive in order to effect at least partial separation of the noncolloidal fraction; and r covering the concentrated colloidal fraction.

11. A process for improvin the electrical conductivity of a combustible organic liquid boiling in the range of from 75 to 750 F., said process comprising selecting an antistatic additive which additivecomprises a colloidal fraction and a noncolloidal fraction; dialyzing said'additive in order to effect at least partial separation of the noncolloidal fraction; recovering the concentrated colloidal fraction; adding said'colloidal concentrated fraction to said combustible organic liquid in a minor amount sufficient to increase the electrical conductivity of said liquid to a value greater than l lO- mhos per centimeter;

12. A process for concentrating the active fraction of an antistatic additive, which process comprises dialyzing said antistatic additive employing an organic liquid as the dialysis medium and recovering the concentrated undialyzed fraction, which fraction has an enhanced ability to promote electrical conductivity.

13. A process as defined by claim 12 wherein the organic liquid is a hydrocarbon boiling in the range between 75 and 750 F.

14. A process as defined by claim 12 wherein the said antistatic additive is a chromium-containing compound.

15. A process as defined by claim 12 wherein the said antistatic additive is a quaternary ammonium compound.

16. A process as defined by claim 12 wherein the said antistatic additive is an alkyl hydroxy aromatic sulfide.

1 i) 17. A process as defined by claim 12 wherein said dialy- 1,680,349 Urbain Aug. 14, 1928 2,375,957 Stamberger May 15, 1945 2,648,636 Ellis et a1 Aug. 11, 1953 2,758,966 Raymond Aug. 14, 1956 2,951,751 McDermott Sept. 6, 1960 2,974,027 Di Piazza May 7, 1961 FOREIGN PATENTS 503,833 Canada June 22, 1954

Claims (1)

10. A COMBUSTIBLE ORGANIC LIQUID BOILING IN THE RANGE OF FROM 75* TO 750*F., SAID LIQUID CONTAINING A MINOR AMOUNT SUFFICIENT TO INCREASE THE ELECTRICAL CONDUCTIVITY OF SAID LIQUID TO A VALUE GREATER THAN 1X10**-12 MHOS PER CENTIMETER OF A CONCENTRATED COLLOIDAL FRACTION PREPARED BY SELECTED AN ANTISTATIC ADDITIVE WHICH ADDITIVE COMPRISES A COLLOIDAL FRACTION AND A NONCOLLOIDAL FRACTION; DIALYZING SAID ANTISTATIC ADDITIVE IN ORDER TO EFFECT AT LEAST PARTIAL SEPARATION OF THE NONCOLLOIDAL FRACTION; AND RECOVERING THE CONCENTRATED COLLOIDAL FRACTION.