US3126260A

US3126260A - Qgganic liquid composition

Info

Publication number: US3126260A
Authority: US
Priority date: 1959-05-28
Publication date: 1964-03-24
Anticipated expiration: 1981-03-24
Also published as: BE591231A; DE1284009B; NL239642A; GB895086A; FR1258027A; NL103681C

Description

United States Patent Ofifice 3,126,260 Patented Mar. 24, 1964 3,126,260 ORGANIC LIQUID COMPOSITION Johan L. Van der Minne, Pieter H. J. Hermanie, and Corneiis Donwes, all of Amsterdam, Netherlands, assignors to Sheil Oil Company, New York, N.Y., a corporation of Delaware No Drawing. Fiied May 23, 1960, Ser. No. 30,755 (Ilaiins priority, application Netherlands May 28, 1959 Claims. ((11. 44-62.)

This invention relates to novel flammable liquid compositions and to novel additives therefor, and particularly to hydrocarbon liquids of increased electrical conductivity.

The danger of spark discharge over flammable liquids, because of the accumulation of static electrical charges therein, has been of increasing concern in recent years. Many explosions and fires in oil refineries, depots and tankers have been attributed to it. It is generally known that liquid hydrocarbons in particular have a very low electrical conductivity and that electrostatic charging of the liquid may therefore take place when the liquid moves relative to a surface or interface. Such a movement occurs whenever the liquid is pumped through a tube or pipe or when suspended waterdrops settle from the hydrocarbon liquid and is therefore unavoidable in the usual handling of hydrocarbon liquids.

This danger particularly arises when the air, which is in contact with the hydrocarbon, contains between approximately 1 and 7% by volume of hydrocarbon vapor. Thus, at room temperature (approximately 20 C.) heavy gasolines and light kerosenes are extremely dangerous,

At lower temperatures the danger becomes greater with lighter fractions, such as light gasolines, and at higher temperatures the danger becomes greater with heavier fractions, such as heavy kerosenes.

Electrostatic charging occurs to a particularly high degree if hydrocarbons are pumped at high speeds. Heavy gasolines and kerosenes are often used as jet fuels for aircraft turboprop engines and jet aircraft engines. When fueling aircraft the fuels are generally pumped through relatively narrow hoses which makes it necessary to pump them at high speeds. Pumping through filters, as is frequently done when fueling aircraft, may also give rise to high electrostatic charges. It will be clear that in this case the danger of explosions occurring is considerable. However, some danger still exists when hydrocarbons are pumped at lower speeds, such as occurs when storage tanks are filled in refineries, and this danger is greatly increased in the presence of water.

It is known that the formation of electrostatic charges in hydrocarbons can be prevented by increasing their electrical conductivity. It has already been proposed to add a salt for this purpose.

Belgian patent specification No. 563,850 disclosed the addition of a salt of a polyvalent metal, such as chromium, and an alkylated salicylic acid containing at least 1 alkyl substituent having 8 or more carbon atoms to an organic liquid having a dielectric constant of 8 or less. The advantage of the use of the metal salt for increasing the electrical conductivity of these liquids is that they conform to the following five specifications:

(l) The increase of the specific conductivity of petro leum fractions to a value of at least 10- ohmcmf which is necessary to prevent explosion when pumping under unfavorable conditions.

(2) The use of a concentration of less than approximately 10- mol/liter, preferably approximately 10* mol/liter or even lower in order to avoid considerable fouling of engines, nozzles, burner wicks, etc.

(3) Insusceptibility to hydrolysis or extraction by water with which the organic liquids, for example, petroleum fractions, may come into contact during storage or pumpmg.

(4) Slight adsorption of the additive at interfaces, for example, a hydrocarbon-water interface or a hydrocarhon-metal interface to prevent a decrease in the concentration.

(5) Ready solubility of the additive even at low temperatures.

In practice it has been found, however, that the electrical conductivity of the liquids containing the abovementioned metal salts, for example, petroleum fractions, begins to decrease after some time. During the same period this decrease in the electrical conductivity is higher in the presence of water. The cause of the reduction of the electrical conductivity is not known.

It is accordingly a principal object of this invention to provide improved flammable liquids, especially in respect to the electrical conductivity thereof. It is another object of the invention to provide an improved electrical conductivity additive composition. A more particular object of the invention is to provide such an additive composition wich can be added to flammable liquids to provide an increase in electrical conductivity of greater permanence in storage. It is a still further object of the invention to provide such an additive composition, which, when added to flammable liquids, will provide an increase in electrical conductivity of greater permanence even in the preesnce of water. Other objects will be apparent in the description of the invention.

The above-mentioned Belgian patent specification also states that the said chromium alkyl salicylates may be used together with salts of di-octylsulfosuccinic acid, in particular the calcium salt. This insures that the electrical conductivity of an organic liquid, to which both a chromium alkyl salicylate and a di-octylsulfosuccinic acid salt have been added is higher than the sum of the electrical conductivities obtained by employing the two compounds separately. The electrical conductivity also decreases after some time when the calcium salt of di-octyl succinic acid is used in combination with a chromium alkyl salicylate. When the organic liquid to which these compounds have been added is contacted with water, the electrical conductivity is reduced. The longer this liquid is in contact with water the lower will be the electrical conductivity.

It has now been found that the decrease of the electrical conductivity of organic liquids having a dielectric constant of 8 or less and containing a salt of a polyvalent metal, such as chromium, and an alkylated salicylic acid containing at least 1 alkyl substituent having 8 or more carbon atoms, is counteracted by the addition of certain polymeric compounds.

According to the invention, soluble polymers or copolymers directly or indirectly prepared and containing one or more acid groups, including anhydrides or salts of these polymeric compounds, are added to the organic liquids.

The invention therefore relates to organic liquid compositions having increased electrical conductivity containing a polyvalent metal salt of an alkylated salicylic acid, containing at least one alkyl substituent having 8 or more carbon atoms, and a polymeric material which is soluble in the organic liquid and which contains at least one acid group.

By an acid group is meant a carboxyl group or oxy-acidderived group containing sulfur or phosphorus, and the corresponding anhydrides, and salts of such groups.

The polymeric compounds of the invention have a stabilizing effect on the electrical conductivity of organic liquids of the above type in which salt of polyvalent metals and an alkylated salicylic acid are present. In many cases they even improve the electrical conductivity of such compositions, It has even been observed that the polymeric compound used in combination with the abovementioned metal salts of alkyl salicylic acid produces an unexpected synergistic effect, in other words, that the electric conductivity of the organic liquid containing both additives is greater than the sum of the electrical conductivities resulting from the use of each of the two additives separately. Another phenomenon observed is that the electrical conductivity of the composition produced according to the invention becomes higher after some time, even in those cases in which they come in contact with water. The molecular weight of the polymeric compounds added may be a factor since it has been found that the addition of a polymeric compound having a relatively low molecular weight, for example, 50,000, insures that the maximum electrical conductivity is attained in a shorter period than when a polymeric compound having a relatively high molecular weight, for example, 400,000, is added.

The molecular weight of the polymeric compounds of the invention may vary within wide limits. The molecular weight is preferably at least 1x10 and in particular at least 5X10. The molecular weight is preferably not more than 2 l0 and in particular not more than As stated above, the polymeric compound of the invention should be soluble in the organic liquids of which it is desired to increase the electrical conductivity. In this connection it is advisable to use compounds with side chains containing saturated hydrocarbon groups having at least 8 carbon atoms. This chain may be branched or straight and may contain polar groups, for instance hydroxyl groups.

If a copolymer is used one of the monomers may be an unsaturated carboxylic acid, preferably an unsaturated aliphatic carboxylic acid or an anhydride thereof. Readily available commercial acids are acrylic acid and methacrylic acid. It is, however, also possible to use other compounds as starting materials such as alpha-ethylacrylic acid, crotonic acid, isocrotonic acid, tiglic acid, angelic acid, vinyl acetic acid, vinyl propionic acid, maleic acid and fumaric acid. Mixtures of unsaturated carboxylic acids may also be used.

The unsaturated organic carboxylic acids or anhydrides thereof may be directly or indirectly copolymerized with branched or straight mono-olefins, particularly alphaolefins, having at least 10 carbon atoms or with esters of unsaturated organic carboxylic acids and saturated alcohols or with esters of saturated organic carboxylic acids and unsaturated alcohols, which esters contain a saturated branched or straight carbon chain containing at least 8 carbon atoms. This carbon chain may contain one or more polar groups, for example a hydroxyl group.

Examples of alpha-olefins are decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexacene, heptadecene, octadecent, nonadecene, eicosene, heneicosene, docosene, tricosene, tetracosene, pentacosene, hexacosene, heptacosene, octacosene, nonacosene, triacontene, hentriacontene, dotriacontene, tritriacontene, tetratriacontene, pentatriacontene, hexatriacontene, heptatriacontene, octatriacontene, nonatriacontene and tetracontene. These olefins are preferably obtained by cracking paralfin waxes. Mixtures of the said olefins may also be used for the production of the copolymers of the invention.

The above esters may be esters of an unsaturated carboxylic acid such as acrylic acid or methacrylic acid with primary, secondary or tertiary alcohols having branched or straight carbon chains, for example lauryl or stearyl alcohol or esters of a saturated carboxylic acid for example, lauric acid or stearic acid with an unsaturated alcohol such as vinyl alcohol.

According to the invention the following copolymers may be used:

stearyl methacrylate/methacrylic acid;

beta-hydroxyethyl methacrylate/stearyl methacrylate/ methacrylic acid;

beta-hydroxyethyl methacrylate/lauryl methacrylate/ methacrylic acid;

lauryl methacrylate/methacrylic acid;

lauryl methacrylate/stearyl methacrylate/methacrylic acid;

lauryl methacrylate/beta-diethylamino-ethyl methacrylate/methacrylic acid;

stearyl methacrylate/beta-diethylamino-ethyl methacrylate/methacrylic acid;

stearyl methacrylate/Z-methyl-5-vinylpyridine/methacrylic acid;

lauryl methacrylate/stearyl methacrylate/2-methyl-5 vinylpyridine/methacrylic acid;

lauryl methacrylate/N-vinylpyrrolidone/methacrylic acid;

stearyl methacrylate/N-vinylpyrrolidone/methacrylic acid;

stearyl methacrylate/crotonic acid;

stearyl methacrylate/ vinyl acetic acid;

lauryl methacrylate/stearyl methacrylate/crotonic acid;

lauryl methacrylate/stearyl methacrylate/ vinyl acetic acid;

stearyl methacrylate/beta/diethylamino-ethyl methacrylate/crotonic acid;

lauryl methacrylate/stearyl methacrylate/beta-diethylamino-ethyl methacrylate/vinyl acetic acid;

stearyl methacrylate/N-vinylpyrrolidone/crotonic acid;

stearyl methacrylate/ N-vinylpyrrolidone/ vinyl acetic acid,

cetene-l/maleic anhydride;

stearyl methacrylate/cetene-l/vinyl acetic acid;

lauryl methacrylate mixtures of tetradecene, pentadecene,

hexadecene, heptadecene and octadecene/methacrylic acid.

The polymeric compounds of the invention need not be directly produced, but they may also be indirectly prepared. The corresponding compounds containing ester groups or a nitrile group may, for example, first be prepared. They may subsequently be entirely or partly saponified. It is also possible to introduce the acid groups in a polymeric compound.

The polymeric compounds of the invention are preferably derived from nitrogen-free monomers.

The alkaline earth metal salts, particularly the calcium salts of the above-mentioned polymeric compounds may be used and are preferred. The salts of monovalent or polyvalent organic nitrogen bases are also suitable for use.

The polymeric compounds of the invention need only be used in a very small concentration to obtain the desired effect. A quantity of, for example, approximately 0.0000l% by weight, preferably at least 0.0002% by weight, added to the organic liquid of which it is desired to increase the electrical conductivity is sufiicient. A very suitable quantity is, for example, 0.001% by weight, although larger quantities may also be employed. A quantity of not more than approximately 0.02% by weight is generally required for the present object of the invention.

Salts of a metal with an atomic number higher than 21 and lower than 29 and an alkylated salicyclic acid are preferably used for increasing the electrical conductivity of the organic liquids of the above-mentioned type. According to the invention the alkylated salicylic acid should contain at least 1 alkyl substitutent having 8 or more carbon atoms. The number of carbon atoms in the alkyl substituent is preferably between 10 and 22, for example, between 14 and 18. In addition to this alkyl substituent, other substitucnts may also be present. Salts of trivalent metals are preferred. Such salts of chromium are elfective for increasing the electrical conductivity of, for example, hydrocarbons. The chromium salts may be neutral or basic salts. They may be used in a pure state or may contain contaminations resulting from the preparation, such as phenols and phenates. This preparation is described in the above-mentioned Belgian patent specification.

The concentration of the metal salt of the alkyl salicylic acid required to protect sufiiciently organic liquids such as liquid hydrocarbons against an electrostatic phenomena may be extremely small. A concentration of the metal salt equivalent to at least 1 10* gram atoms of the metal per liter of the liquid base is generally sufficient, although l l gram atoms will sufiice in certain cases. Since it is not desirable to employ an excess of the additive in inorganic liquids, such as liquid hydrocarbons, it is preferable to use not more than 1 10- or more preferably at most 1 '10- gram atoms of the metal in the form of the metal salt per liter of the liquid base. Particularly suitable concentrations are in the range of from 1 10- to 1 10' gram atoms of the metal per liter of liquid base.

In many cases it is desirable to employ the above-described metal salts of the alkylated salicylic acid along with other compounds which synergistically increase the favorable effect of these metal salts on the electrical conductivity. The salts of di-octylsulfosuccinic acid, particularly the calcium salt, are especially suitable for use in combination With the metal salts according to the invention. These salts of di-octylsulphosuccinic acid may be employed in quantities in the range of from approximately l to approximately 1 l0 gram atoms of metal per liter, prefenably from l 10-' to 1X10 gram atoms of metal per liter of the liquid base.

By the expression organic liquid is meant single organic liquids as well as mixtures of liquid organic compounds, it being understood that such mixtures may contain components having a dielectric constant of more than 8, provided the dielectric constant of the mixture is 8 or lower.

The invention is particularly applicable to liquid hydrocarbons. It is of very great importance in connection with volatile organic liquids, for example, organic liquids containing not more than 15, and in particular not more than 12, carbon atoms in the molecule, or liquid mixtures of organic compounds containing an average of not more than 15, and particularly of not more than 12, carbon atoms in the molecule, it being understood that the separate components of such mixtures may contain more than carbon atoms in the molecule. Examples of organic liquids to which the invention is applicable are aliphatic hydrocarbons or mixtures thereof, such as hexane, heptane and corresponding unsaturated hydrocarbons; aromatic hydrocarbons or mixtures thereof, such as ben zene and toluene; cyclic aliphatic hydrocarbons, such as decalin; mixtures of various aliphatic, cyclic aliphatic and aromatic hydrocarbons; halohydrocarbons; ketones; esters; ethers such as diethyl ether and dioxane; carbon disulfide; thioethers and thioalcohols.

The invention may be particularly applied to light petroleum fractions boiling in the gasoline and kerosene boiling range, for example, fuels for spark-ignition internal combustion engines and fuels for gas turbines used for the propulsion of aircraft. -It may also be applied to such heavier fractions that boil within the gas oil boiling range.

The following polymeric compounds are used in the examples given below:

A. Stearyl methacrylate/methacrylic acid;

B. Beta-hydroxyethyl methacrylate/stearyl methacrylate/ methacrylic acid;

C. The polyethylene-imine salt of the copolymer beta- .hydroxyethyl methacrylate/lauryl methacrylate /stearyl methacrylate/methacrylic acid;

D. The calcium salt of the copolymer lauryl methacrylate/methacrylic acid;

anhydride.

"E. Cetene-l/di-normal-butyl ester of maleic acid/maleic Each of these polymeric compounds is hereinafter referred to by the foregoing letter designation.

The polymeric compound A was produced as follows:

An amount of stearyl methacrylate corresponding to 338 parts by weight and 17.2 parts by weight of methacrylic acid were dissolved in 1200 parts by weight of carbon tetrachloride. 1.5 parts by Weight of dodecyl mercaptan were added to the resultant solution. 1.73 parts by weight of azo-isobutyronitrile were then added with stirring while the solution was kept at a temperature of 75 C., after which the mixture was stirred for 1 hour and 45 minutes. The mixture was poured out into 3000 parts by weight of methanol after being cooled to a temperature of 20 C. The polymeric compound was separated from the solvent and then freed from the latter by evaporation in vacuo at a temperature of 0 C. The yield was 318 parts by weight, the molar ratio of the monomers stearyl methacrylate and methacrylic acidin the resultant copolymer being 3.621.

The polymeric compound B was produced as follows:

An amount of stearyl methacrylate corresponding to 338 parts by weight, -26 parts by weight of beta-hydroxyethyl methacrylate and 8.6 parts by weight of methacrylic acid were dissolved in 400 parts by weight of nitrobenzene. After addition of 40 parts by weight of benzoylperoxide, copolymerization took place at a temperature of C. Twenty parts by weight of benzoyl peroxide were added at half hourly intervals. The reaction mixture was cooled and poured out in 1200 parts by weight of methanol two hours after a total quantity of 60 parts by weight of benzoyl peroxide had been added. After removal of the methanol layer, the layer containing the desired polymeric compound was poured out in a mixture of 800 parts by weight of methanol and 400 parts by weight of benzene. The polymeric compound thereupon separated. After the resultant product was air-dried, the yield was 334 parts by weight and the molar ratio of the monomers beta-hydroxy-ethyl methacrylate, stearyl methacrylate and methacrylic acid was 10:2: 1.

The polymeric compound C was produced as follows:

An amount of stearyl methacrylate corresponding to 3718 parts by weight, 2794 parts by weight of lauryl methacrylate, 260 parts by weight of beta-hydroxy-ethyl methacrylate and 103.3 parts by Weight of methacrylic acid were dissolved in 27,500 parts by weight of benzene. The copolymerization was initiated by bringing the solution to a temperature of 80 C. and adding 52 parts by Weight of benzoyl peroxide. A second solution was also prepared by adding 312 parts by weight of beta-hydroxyethyl-methacrylate and 86 parts by Weight of methacrylic acid to 1592 parts by weight of benzene. Forty-five minutes after copolymerization began in the first solution the second solution was added portionwise to the first solution. The reaction mixture was then poured out in methanol. The resultant copolymer was dissolved in benzene, after which the solvent was removed by evaporation in vacuo at a temperature of 0 C. Thus, 6620 parts by Weight of copolymer were obtained in which the molar ratio of the monomers stearyl methacrylate, lauryl methacrylate, beta-hydroxy-ethyl methacrylate and methacrylic acid was 5:5:2z2.

The polyethylene-imine salt of this copolymer was prepared. To this end parts by weight of the copolymer were dissolved in 380 parts by weight of benzene and then mixed with a solution of 1.5 parts by weight of polyethylene-imine in 67 parts by Weight of water. The solvents were removed by heating the reaction mixture until a temperature of 125 C. was reached. Any solvent present in the reaction mixture was subsequently removed by evaporation in vacuo at a temperature of 75 C. The yield of the resultant polyethylene-imine salt was parts by weight.

The polymeric compound D was produced as follows:

An amount of lauryl methacrylate corresponding to 254 parts by weight was copolymerized with 86 parts by weight of methacrylic acid by heating the solution of the two substances in 1300 parts by weight of xylene for 22 hours at 130 C. after 1.5 parts by weight of ditert. butylperoxide had been added. The solvent was then removed by distillation of the reaction mixture in vacuo, the temperature rising to 150 C. The resultant copolymer containing the monomers lauryl methacrylate and methacrylic acid in a molar ratio of 4:1 was neutralized with calcium hydroxide by adding 0.75 part by weight of calcium hydroxide to 15 parts by weight of copolymer, dissolved in 30 parts by weight of xylene and 2 parts by weight of methanol. After boiling under reflux for one hour the greater portion of the solvents was removed by distillation. The remainder of the solvents was removed by vacuum distillation after filtration of the solution. A yield of 15.3 parts by weight of calcium salt having a calcium content of 1.54% by weight was obtained.

The polymeric compound E was produced as follows:

Cetene-l and maleic anhydride, dissolved in xylene in a molar ratio of 1:1, were copolymerized at a temperature of 130 C. The copolymerization was initiated by adding di-tert. butyl peroxide in a quantity of 0.1% by weight, based on the mixture of the monomers. The copolymerization lasted 24 hours. During the copolymerization a further quantity of 1% by weight di-tert. butyl peroxide was added portionwise to the reaction. The resultant copolymer of cetene-l and maleic anhydride, which had a molecular weight of 5000 and contained 1 mol of cetene-l per mol of maleic anhydride, was partly esterified with n-butyl alcohol. To this end 20 parts by weight of n-butyl alcohol and one part by weight of beta-naphthalene sulfonic acid were added to 50 parts by weight of the resultant copolymer dissolved in 100 parts by weight of benzene. The resultant solution was distilled, the water present in the distillate being removed and the remainder of the distillate being continuously returned in the boiling solution. The liquid was cooled and washed with water after 0.7 part by weight of water had separated. The volatile components were removed by evaporation under vacuum, which yielded 68 parts by weight of the polymeric compound E, the molar ratio of the monomers cetene-l, di-butyl ester of maleic acid and maleic anhydride being 10:911.

EXAMPLE I To a gasoline having an initial boiling point of 80 C. and a final boiling point of 110 0, there was added such a quantity of a xylene solution of a chromium C -C alkyl salicylate, containing C -C -alkyl phenol, which solution contained 2.10% by weight of chromium, that the chromium content in the gasoline was 1.44 10- gram atoms of chromium per liter. The electrical conductivity of part of the mixture was measured immediately after. The change in the electrical conductivity was then determined by again measuring it 7 days and 35 days afterwards.

Ten percent by volume of water was added to another part of the mixture after which the whole mixture was shaken. The electrical conductivity of the gasoline layer was determined after settling. Seven days afterwards the liquids were again shaken and the electrical conductivity of the gasoline layer formed determined, and this was repeated after 35 days, calculated from the time when water was added to the mixture.

Still another part of the solution of the chromium alkyl salicylate in the gasoline was divided into separate portions. A polymeric compound in a quantity of 0.001 by weight was added to each of the portions. The polymeric compounds used are mentioned in Table I. The electrical conductivity of these portions was measured. The change in the electrical conductivity was then determined by again measuring it after 7 days and 35 days.

A fourth part of the solution of the chromium alkyl salicylate in the gasoline was also divided into separate portions. A polymeric compound was added to each of these portions in a quantity of 0.001% by weight, the same polymeric compounds as referred to in the preceding paragraph being used. After addition of 10% by volume of water to each portion and shaking the liquid mixture the electrical conductivity of the gasoline layer was determined after settling. Seven days afterwards the liquids were again shaken and the electrical conductivity of the resultant gasoline layer of each portion was determined, and this was repeated after 35 days calculated from the time when water was added to each portion.

The results obtained are assembled in the following table.

Table I Electrical conductivity in units (1 unit =10- ohm- -cmfl) after- Composition 0 days 7 days 35 days Without ol eric compound Dryiiff i 400 200 13 After shaking with water. 400 150 With polymeric compound A Dry 442 515 555 After shaking with watcr. 430 850 6, 250 With polymeric compound B Dry 595 1,000 1,180 After shaking with water 567 1, 440 6, 350 With polymeric compound 0 Dry 3, 300 4, 900 4, 500 After shaking with water. 3, 300 6, 800 5, 700 With polymeric compound D Dry 1, 280 5, 000 5, After shaking with W&tGI' 1, 320 8, 000 7, 000 With polymeric compound E Dry 465 940 1, 200 After shaking with Water"--- 473 1, 900 2, 500

The above table shows that without the addition of a polymeric compound of the invention the electrical conductivity of a gasoline to which 1.44 10- gram atoms of chromium as chromium C -C alkyl salicylate have been added decreases after some time and this decrease is more pronounced when the gasoline is in contact with water than when it is kept dry. This decrease is counteracted by the addition of a polymeric compound according to the invention. In many cases there is even an increase of the electrical conductivity in proportion to the time. This increase is even larger when the gasoline with the chromium alkyl salicylate and the polymeric compounds according to the invention is contacted with water. It should be noted that the polymer compounds C and D cause an immediate increase in the electrical conductivity of the gasoline, containing the chromium alkyl salicylate.

When the portions of the gasoline to which 1.44 10- gram atoms of chromium in the form of chromium C C alkyl salicylate and the polymeric compounds A, B, C, D and E, each in a quantity of 0.001% by weight, have been added, were shaken with 10% by volume of a 0.5% by weight of aqueous solution of a calcium hydroxide instead of with 10% by Volume of water, the results summarized in Table II were obtained.

Table II Electrical conductivity in units (1 unit=10 ohm -cm.- alter- Table II shows that the contact of the gasoline with the caustic alkaline solution considerably increases the favorable effect of a polymeric compound of the invention on the electrical conductivity of the gasoline containing the chromium Cry-C alkyl salicylate.

9 EXAMPLE 11 To the solution of chromium alkyl salicylate in gasoline, as described in paragraph 1 of Example I, there was added a solution of the calcium salt of di-octylsulfosuccinic acid containing 2.00% by weight of calcium in the same gasoline as the one to which the chromium alkyl salicylate was added in such a quantity that the calcium content of the gasoline was 11.78 10 gram atoms per liter. The electrical conductivity of this composition was measured.

A part of this composition was divided into three portions. A quantity of 0.001% by weight of the polymeric compounds A, C and D was added to each of these portions. The electrical conductivity of these portions was determined. A part of each portion was then intimately mixed with 1% by volume of water. The electrical conductivity of the gasoline layer was determined one day and two days afterwards. Another part of each portion was also intimately mixed with 1% by volume of an aqueous solution containing 30% by weight of sodium hydroxide and 5% by weight of sodium nitrite. The electrical conductivity of the gasoline layer was determined one day and two days afterwards.

Similar experiments were carried out with another part of the composition prepared as described in the first paragraph of this example, it being understood that a quantity of 0.0002% by weight of the polymeric compounds A, C and D was used instead of 0.001% by weight.

The following table summarizes the results obtained Table III Electrical conductivity in units (1 unit ohm- -cm Polymer After intimate com- After intimate mixing with Composition pound mixing with sodium percent water hydroxideby weight Dry sodium nitrite solution After After After After lday 2days lday Zdays Without polymeric) compound 4,400 720 470 140 320 With polymeric compoundA 0.001 3,550 3,300 3,500 1,700 1,930 With polymeric compoundC i 0.001 4,400 4,000 5,500 2,300 2,150 With polymeric compound D 0.001 5,500 7,800 7,300 3,050 3,200 With polymeric compoundA 0.0002 4,600 2,900 3,200 2,200 2,450 With polymeric compoundC 0.0002 3,650 2,600 2,450 990 1,010 With p olymeric ccmpoundD 0.0002 5,900 3,850 4,100 1,870 1,870

The 'aforegoing shows that the presence of a polymeric compound counteracts the decrease in the electrical conductivity of the gasoline to which chromium C C alkyl salicylate and the calcium salts of di-octyl sulfosuccinic acid are added even if the gasoline is contacted with an aqueous solution containing :a sodium hydroxide and sodium nitrite.

EXAMPLE III Similar experiments as described in Example II were carried out with a gasoline having an initial boiling point of 80 C. and a final boiling point of 110 C., to which a chromium C -C alkyl salicylate had been added in the quantity indicated in the first paragraph of Example I. The polymeric compounds A and C were added in different concentrations to the gasoline and the electrical conductivity of the resultant compositions was measured in a dry and in a wet state. The following table summarizes the results obtained.

Table IV Electrical conductivity in units Polymer (1 unit=10- ohm- -cm- Composition compound 5 percent by weight Dry After After After 1 day 2 days 5 days Without polymeric compound 305 150 143 104 With polymeric com- 10 pound A 0. 00002 260 320 350 285 D 0. 00020 365 325 470 450 0. 00200 410 610 650 7 40 0.02000 740 1, 220 1, 330 1, 260

We claim as our invention:

1. An organic liquid composition having increased electrical conductivity consisting essentially of an organic liquid normally having a dielectric constant of not more than 8 and a conductivity additive composition consisting essentially of (1) a salt of a polyvalent metal and an alkylated salicylic acid containing at least one alkyl substituent having eight or more carbon atoms and (2) an organic liquid-soluble nitrogen-free copolymer of an unsaturated aliphatic carboxylic compound, selected from the group consisting of acids, acid anhydrides and alkaline earth metal salts, and from one to three organic comonomers selected from the group consisting of alpha-olefins having at least 10 carbon atoms, esters of unsaturated organic carboxylic acids and unsaturated alcohols and esters of saturated organic carboxylic acids and unsaturated alcohols, said esters containing a saturated aliphatic chain of at least 8 carbon atoms, and said copolymer having a molecular weight of from 1x10 to 2x10 the amount of the additive composition being such as to provide at least l l0 gram atoms of polyvalent metal per liter and from 0.00001 to 0.02% by weight of polymeric material, basis the organic liquid.

2. An improved electrical conductivity additive composition consisting essentially of (l) a salt of a polyvalent metal and an alkylated salicylic acid containing at least one alkyl substituent having six or more carbon atoms and (2) an organic liquid-soluble copolymer of an unsaturated aliphatic carboxylic compound, selected from the group consisting of acids, acid anhydrides and alkaline earth metal salts, and from one to three organic comonomers selected from the group consisting of alpha-olefins having at least 10 carbon atoms, esters of unsaturated organic carboxylic acids and saturated alcohols and esters of saturated organic carboxylic acids and unsaturated alcohols, said esters containing a saturated aliphatic chain of at least 8 carbon atoms, and said copolymer having a molecular weight of from 1x 10 to 2 X10 3. An improved electrical conductivity additive composition consisting essentially of (1) a salt of a polyvalent metal and an alkylated salicylic acid containing at least one alkyl substituent having at least 6 carbon atoms and 2) a polymeric material according to the polymers recited in claim 1 the salt of the polyvalent metal being present in an amount suflicient to materially increase the conductivity of an organic liquid normally having a dielectric constant of not more than 8, and the amount of the polymeric material being sufiicient to substantially stabilize the electrical conductivity efi'ect of the salt of polyvalent metal.

4. The composition of claim 1 in which the polymeric material is a copolymer of an unsaturated aliphatic carboxylic acid, an anhydride of an unsaturated aliphatic carboxylic acid and a mono-olefin having an aliphatic chain of at least 10 carbon atoms.

5. The composition of claim 4 in which one of the monomers of the copolymer is selected from the group consisting of acrylic and methacrylic acids.

6. The composition of claim 4 in which one of the monomers of the copolymer is selected from the group consisting of maleic and fumaric acids.

7. The composition of claim 1 wherein the salt of the alkylated salicylic acid contains a metal having an atomic number between 21 and 29.

8. The composition of claim 7 wherein the metal is chromium.

9. The composition of claim 1 in which the alkylated salicylic acid contains at least one alkyl substituent having from 10 to 22 carbon atoms.

10. The composition of claim 1 in which the additive composition also contains the calcium salt of di-octylsulfosuccinic acid in an amount sufiicient to provide a con- 12 centration of from 1 10- to 1 l0- gram atoms of metal per liter, basis the organic liquid.

References Cited in the file of this patent UNITED STATES PATENTS 2,469,737 McNab et a1. May 10, 1949 2,800,452 Bondi et a1. July 23, 1957 2,800,453 Bondi et a1. July 23, 1957 2,892,690 Lowe et a1. June 30, 1959 2,913,439 Bondi et a1 Nov. '17, 1959 3,013,868 Skei et al. Dec. 19, 1961 FOREIGN PATENTS 749,898 Great Britain July 6, 1956

Claims

1. AN ORGANIC LIQUID COMPOSITION HVING INCREASED ELECTRICAL CONDUCTIVITY CONSISTING ESSENTIALLY OF AN ORGANIC LIQUID NORMALLY HAVING A DIELECTRIC CONSTANT OF NOT MORE THAN 8 AND A CONDUCTIVITY ADDITIVE COMPOSITION CONSISTING ESSENTIALLY OF (1) A SALT OF A POLYVALENT METAL AND AN ALKYLATED SALICYLIC ACID CONTAINING AT LEAST ONE ALKYL SUBSTITUENT HAVING EIGHT OR MORE CARBON ATOMS AND (2) AN ORGANIC LIQUID-SOLUBLE NITROGEN-FREE COPOLYMER OF AN UNSATURATED ALIPHATIC CARBOXYLIC COMPOUND, SELECTED FROM THE GROUP CONSISTING OF ACIDS, ACID ANHYDRIDES AND ALKALINE EARTH METAL SALTS, AND FROM ONE TO THREE ORGANIC COMONOMERS SELECTED FROM THE GROUP CONSISTING OF ALPHA-OLEFINS HAVING AT LEAST 10 CARBON ATOMS, ESTERS OF UNSATURATED ORGANIC CARBOXYLIC ACIDS AND UNSATURATED ALCOHOLS AND ESTERS OF SATURATED ORGANIC CARBOXYLIC ACIDS AND UNSATURATED ALCOHOLS, SAID ESTERS CONTAINING A SATURATED ALIPHATIC CHAIN OF AT LEAST 8 CARBON ATOMS, AND SAY COPOLYMER HAVING A MOLECULAR WEIGHT OF FROM 1X10**4 TO 2X10**6, THE AMOUNT OF THE ADDITIVE COMPOSITION BEING SUCH AS TO PROVIDE AT LEAST 1X10**8 GRAM ATOMS OF POLYVALENT METAL PER LITER AND FROM 0.00001 TO 0.02% BY WEIGHT OF POLYMERIC MATERIAL, BASIS THE ORGANIC LIQUID.