US2364502A - Fuel compositions - Google Patents

Description

Patented Dec. 5, 1944 FUEL COMPOSITIONS John C. Zimmer, Union, and Jones I. Wasson,

Townley, N. J., assignors to Standard 011 Development Company, a corporation of Delaware No Drawing. Application December 30, 1941, Serial No. 424,929

13 Claims.

supply lines and engine parts, particularly in the presence of moisture due to atmospheric condensation or water contamination from storage, etc. They may lead to bad engine conditions, to lowering of anti-knock value in a spark ignition engine motor fuel, and to certain forms of deterioration in the appearance of the fuel.

Undesira-ble changes in motor fuel compositions may arise from a number of different causes, and it is diflicult to correct deleterious effects of all causes by any single stabilizing agent. For example, anti-oxidants have been used to increase the resistance of a fuel to oxidation which might cause change of color and formation of gum. But this correction, by itself, is not always sufficient, for it has been found that low boiling hydrocarbon liquids free from gum-forming bodies are subject to discoloration by sunlight, and even many of the well-known anti-oxidants become discolored by sunlight or tend to make the oil product cloudy.

Another form of undesirable change occurring particularly in spark-ignition engine fuels is due to the instability of metallo-organic anti-knock addition agents, as for example, tetraethyl lead, for these agents have the tendency to decompose and form a precipitate in the fuel, especially when exposed to sunlight or when stored in contact with certain metals frequently used in the construction of fuel containers.

Still another type of deterioration encountered with hydrocarbon fuel distillates is their discoloration by the action of metals, which action is accentuated when the oils are heated to elevated temperatures.

An object of the present invention is to protect fuel compositions against the undesirable effects of sunlight.

Another objectis to counteract the undesirable effects of corrosive impurities or corrosive acidforming substances incorporated in the hydrocarbon fuel oils.

A specific object is to preserve the clarity and stability of motor fuels containing metallo-organic anti-knock agents with improvement and preservation of the efiectiveness of these agents. A further specific object is to confer on the fuel distillates an inertness to metals which aids in preventing discoloration or contamination of the fuel, the surface of the metal contacting the fuel being made passive at the same time to corrosion by impurities in the fuel.

The type of agent utilized for the purpose of this invention is characterized by metal salts of resinous condensation products formed by reacting an alkyl phenol with formaldehyde and hydrogen chloride, then reacting the resulting phenolic condensation product with ammonia or an equivalent strong base, e. g., an amino compound, an organic nitrogen base, or other organic bases which may contain other base-forming metalloids, such as phosphorus. Liquid ammonia is a highly preferred base reactant. Next in order of importance come the aliphatic amines and aromatic amines, primary, secondary and tertiary. An important factor in the preparation and use of the described metal alts is that their effectiveness and oil-solubility are increased with the length of the alkyl substituent inthe phenol nucleus employed in forming the resin and by having a number of the alkylated phenol molecules condensed into the resin molecule.

Even though the initial phenolic eactant contains a long alkyl or aliphatic substituent group, which in ordinary types of reaction lowers the reactivity of the phenolic compounds, the reaction for preparing the resins mentioned goes with great ease. The complete reaction in preparing the resins may be considered as involving two stages: first, the substitution of a halogenated aliphatic radical in the aromatic nucleus of the phenolic compound; and second, a, splitting out of the halogen by condensation of the substituted phenolic compound with the base reactant.- Very little halogen, and preferably none, is left in the final resinous product, and on the average two or more alkyl phenol molecules become combined with a single molecule of the base reactant in forming the resin.

The preparation of the preferred resins and their metal salt derivatives are illustrated by the following:

Procedure Into a solution of 18 parts by weight of paraformaldehyde and 100 parts by weight of strong phenol (para, tetramethylbutyl phenol) in benzol solution (50% by weight) were added in the course of one-half hour, while stirring well, the temperature increasing from about C. to 50 C. The stirring was continued at 50 0., for an hour after the alkylated phenol had been added, and during this time a feeble current of hydrogen chloride was conducted into the solution. The alkyl phenol-formaldehyde-hydrogen chloride condensation product formed remained in solution'in the benzol and was separated from the aqueous hydrochloric acid mother liquid.

In the second stage of the resin formation, the separated benzol solution of the condensation product was placed in a beaker, and a dilute liquid ammonia solution in isopropyl alcohol was added to this solution while stirring until a fair excess, about 10%, of ammonia was present. This mixture was then transferred to a bomb and heated therein for about 16 to 20 hoursat 110 C. without further agitation. The pressure developed during heating ranged from about 20 lbs. to 40 lbs/sq. in. The material in the bomb reacted vigorously with considerable evolution of heat. After the reaction was complete in the bomb, the reaction mixture comprising ammonium chloride, an ammonium derivative of the phenolformaldehyde-hydrogen chloride condensation product, and isopropyl alcohol, was transferred to an open vessel wherein it was diluted with .erally, the exact mechanism of the reaction is not entirely understood. In the first stage, the

alkyl phenol may be regarded as condensing with the reaction .product of the hydrogen halide and aldehyde, i. e., with chloromethy1 alcohol, or, as

condensing with formaldehyde, and the con-.

densation product thereof being condensed with the hydrogen halide. product of this first stage reaction may be considered as containing chloromethy1 alkyl phenols represented by the simplified formula:

R-A1(OH) 'CH2C1 wherein R represents alkyl substituents of the phenol in the aromatic nucleus, Ar. Chlorine analysis of this product indicates that approximately one chloromethy1 (-CH2C1) group is introduced on the average into one of the alkyl phenol molecules,R-Ar(OH In the second stage of the reaction, the condensation product of the alkyl phenol, the formaldehyde, and the hydrogen halide, constituted in the form of a chloromethy1, alkyl, phenol splits off the halogen in undergoing a further condensation with the organic base, such as ammonia, and thus the alkyl phenol radical becomes united with the metalloid inthe base radical through methylene groups (-CH 2-) thereby forming complex resinous compounds containing the following type of grouping:

' wherein, as before, Rem-(OH) represents an alkyl phenol group with the trivalent nitrogen atom Either way, the resulting N attached to the aromatic nucleus through the methylene group (-CHz-), the nitrogen atom having its remaining valences satisfied by hydrogen or organic radicals,v (R'), e. g., alkyl, cycloalkyl, aryl, or by more than hydroxy alkyl benzyl radical, as for example, in the following types of compounds:

In the simplest reaction with ammonia the primary amine apparently may be formed, but from the analysis of the complex resinous products it is found that the more complex secondary and tertiary amines are formed. Analysis of separated fractions of the product obtained by solvent extraction indicates that on an average about two and more of the phenolic radicals are combined with one nitrogen atom in the base radical so that principally the product may be considered as having a compositional formula corresponding to that of secondary amines. It is not necessary to fractionate the resinous product in order to form the desired metal salt derivatives to be used as the fuel blending agents, but a fractionation may be made if so desired.

The resinous base derivatives of the alkyl phenol-aldehyde-hydrogen halide condensation products may be represented by the generalized compositional formula:

wherein n is an integer representing the number of chloromethy1, alkyl, phenol molecules condensed with m molecules of the base, n being greater than m and, on an average, equal to about two times m.

A procedure used for forming the metal derivatives consists in dissolving the resin in a solvent such as naphtha or light mineral oil, adding to the solution a slight excess over the combining weight of a metal base which is to be re acted, and agitating the mixture while heating for a sufiicient period to complete the reaction. The concentration of the resin in the solvent may be up to the limit of solubility of the resin and preferably about 5 to 25% in a light solvent such as naphtha or benzene. The reaction is carried out at a temperature of about 78 C. with benzene, and with a less volatile mineral .011, e. g., petroleum lubricating oil, the reaction may be carried out at temperatures as high as C. After the salt is formed, the remaining unreacted metal may be separated out by filtration. The salts of metals having strongly alkaline bases may be formed thus directly, as for example in the case of an alkali metal, such as sodium hydroxide, or very basic alkaline earth metals, such as barium hydroxide. Other metals which form weaker bases, however, may be used in forming the desired salts by first forming the sodium weight of the resin is of the order of 450 grams per mole of sodium hydroxide and of the order of 900 grams per mole of barium hydroxide, thus indicating that two or more moles of alkyl phenol were required to form the combining weight of the resin which, by nitrogen analysis, contained on the average of one mole of the nitrogen base, hence only a fraction, such as about one-half the original phenolic hydroxy groups might remain in the resin unreacted with the metal compound in the salt formation, and some of these hydroxy groups might be changed in some other manner to be made non-reactive.

The metal salt derivatives of the resins are to be blended in small weight proportions of about 0.01 to 0.5% by weight with gasoline, naphthas, kerosene, heating oils, or similar hydrocarbon distillates boiling within the range of about IOU-700 F., depending upon the inherent stability of the fuel, its content of substan'ces'having corrosive tendencies, the particular effectiveness of 'the resin salt stabilizing agent used, the presence and amount of other addition agents in the oil, and conditions to which the fuel composition has to be subjected.

For example, a commercial gasoline containing cracked hydrocarbon was satisfactorily stabilized in color, and with tetraethyl lead blended in the gasoline, not only was the color of the gasoline kept from changing, but the tetraethyl lead was kept from decomposing and precipitating by the addition of the described metal salt derivatives of the resins.

Comparative tests were made as illustrated in the following example:

Eaiample Samples of a gasoline containing 3 cc. of tetraethyl lead per gallon were treated with from 0.02% to 0.05% by weight of the barium salt formed as described, and exposed to intensified sunlight radiation along with untreated samples of the gasoline. The untreated gasoline showed a plainly visible precipitate in an hour, while the samples containing the barium salt stabilizing agent remained clear for periods of three to four days.

. Tests were made on the rust inhibiting ability of the salts described using the A. S. T. M. corroticularly when there is a tendency for moisture to collect within the containers.

Unlike classes of compounds including certain phenols and amino phenols, such as amino phenol, alkyl amino phenol, etc., which have been extensively investigated as oxidation and gum inhibitors, the resins and salt derivatives herein described for stabilizing fuel compositions against sunlight deterioration and corrosiveness appear to be less eifective for inhibiting oxidation. This does not mean that they are entirely devoid of ability to inhibit oxidation of a hydrocarbon oil, but, nevertheless, they serve excellently in accomplishing the objects of the present invention.

The substances described as metal salt derivatives of amino-methyl-alkyl-phenol resins are formed in a manner which prevents the resins from condensing toan infusible and insoluble stage, as occurs in ordinary phenol and formaldehyde condensation reactions. It is noteworthy that the resins are soluble in hydrocarbon oils up to concentrations of about andhigher. It has been found preferable to have the phenol reactants contain alkyl substituents having at least 3 or 4 carbon atoms; the alkyl phenol having isoalkyl substituents containing from 4-12 carbon atoms are particularly preferred. Satisfactory products have been obtained when the sion test method at 140 F. and a still more severe testing method wherein polished steel is contacted with the oil. One sample of the oil was treated with an alkylated phenol oxidation inhibitor. Another sample containing the oxidation inhibitor and 0.05% of the barium salt of the described resin was tested and it was observed that the sample containing the barium salt of the resin contained a minimum amount of rust, whereas the sample untreated by the barium salt of the resin at th conclusion of the test contained a heavier amount of rust.

Accordingly, the stabilizing agents of the present invention serve usefully to render the surfaces of metals in contact with a fuel composition passive and resistant to corrosion when the fuel contains impurities. This inhibiting action is particularly obtained with iron, copper and aluminum, and their alloys. This rust and corrosion preventing action may be beneficially employed while the fuel is undergoing processing, fractionation or refining in order to retard corrosion of the metal apparatus in which the fuel is treated, or may be employed to overcome corrosion of pipe-lines through which fuel is transported, also during storage of fuels in metal containers, paralkyl phenol having up to 18 or more carbon.

atoms, as with an octa-decyl group.

Although very satisfactory procedures for preparing the resins and their salt derivatives have been described with reference to a condensation nitrogen base with a condensation product and an alkyl phenol, formaldehyde and hydrogen chloride, it is to be understood that other procedures maybe employed for preparing resins of similar character, but the prescribed procedure is preferred. In these procedures, the order of the reaction steps may be changed and equivalent reactants may be used. For example, it may be desired to alkylate the intermediate or final resin condensation product to introduce alkyl substituents into the aromatic groups; it may be desired to first react formaldehyde or its equivalent with ammonia, or with a primary, secondary, or tertiary amine to form alkyl-alkylol amines for condensation with the phenol or alkyl phenol; or it may be desired to alkylate the base or the derivative of the phenol condensation product, e. g., with an alkylatin agent such as di-ethyl sulfate, an alcohol, or ketone, by known alkylating methods and with reduction by hydrogen, if needed or desired.

As previously explained, it is the metal salts of the complex resinous condensation products which are particularly efiective for the purpose of the present invention. Hence, simpler products formed by reaction of'only one alkyl phenol with one molecule of formaldehyde and one molecule of, the base should be converted into the desired more complex compounds by a suitable polymerization or condensation so that on the average more than one alkyl phenol group is combined with one atom of the metalloid in the base reactant to form the desired resins. Alkyl phenol units in the resin may be joined together or condensed with one another to be linked to a terminal amino radical represented generally by the generalized formula:

wherein y hydrocarbon radicals denoted by R and the a: hydrogen atoms satisfy remaining valences of the nitrogen, 31 and :1: adding up to 2, as for example, in 'NHz, -N(I-I) (R') or -N(R')z, the hydrocarbon radicals in each instance being similar or dissimilar. On the basis of chemical analysis of the resins on the average of at least about 2 alkyl phenol groups are com- I bined with 1 atom of nitrogen, so that about two atoms of oxygen are also present for each atom of nitrogen, yet in the metal salt derivatives that are formed from these resins only about half the oxygen present may exist in hydroxyl groups which undergo reaction with the metal hydroxide.

Together with small amounts of the described blending agents for stabilizing the fuel compositions against deterioration by sunlight and for counteracting corro'siveness, various other additives may be used in the fuel compositions. For example, thickening agents, dyes, gum fluxes, ignition promoting agents, anti-oxidants, oiliness agents, other corrosion inhibitors, various other anti-knock agents, such as iron carbonyl tin tetraethyl, metallic chelated compounds, etc., depending on the requirements of the fuel.

The present invention is not to be limited to any theory of reaction in the formation of the metal salt derivatives of the resins, nor to any theory on their structural compositions nor on the mechanism by which these agents function. Although there have been shown anddescribed certain specific embodiments of this invention, many. modifications thereof are possible and are intended to be included within the scope thereof.

We claim:

1. A composition of matter comprising a hydrocarbon fuel distillate stabilized by a small quantity of base metal salt of a resinous ammonium condensation product of an alkyl phenolformaldehyde hydrogen halide condensation product, said product containing a nitrogen base radical attached to the aryl nuclei of alkyl phenol radicals through a methylene group and containing more than one akylphenol radical combined with each nitrogen atom, said meta1 replacing the hydroxyl hydrogen in at least one phenolic group in said salt.

2. A motor fuel comprising a hydrocarbon gasoline base fuel blended with a small proportion of a .base metal salt of a resinous ammonium condensation product of, an alkyl phenol-formaldehyde-hydrogen halide condensation product having the general formula RAr(OH)CH2X, in which R represents alkyl substituents of the phenol in the aromatic nucleus Ar, and X represents halogen in which alkyl substituents of the phenol contain at least. four carbon atoms and in which a nitrogen atom is linked through methylene groups to cyclic carbon nuclei of at least 2 alkyl phenol groupsjsaid metal replacing the hydroxyl hydrogen in at least one phenolic group in said salt. a v

3. A stabilized hydrocarbon oil composition comprising a hydrocarbon liquid boiling within the range of about IOU-700 F. blended with a small amount of a resin salt in which chloromethylalkyl phenols having the general formula RAr (OH) CHaC], in which R represents alkyl substituents of-the phenol in the aromatic nucleus Ar, are chemically condensed through a methylene linkage with a less than molar proportion of a nitrogen base into a resin and an alkaline earth metal replaces a substantial amount of hydrogen atoms in phenolic hydroxy groups of the resin.

4. The method of enhancing and preserving the efiectiveness of a lead alkyl anti-knock agent in .a motor fuel blend which comprises adding to said blend about 0.01% to 0.5% by weight of a base metal salt containing a nitrogen base radical attached to a plurality of aromatic nuclei of alkyl phenol radicals through methylene groups, said metal replacing the hydroxyl hydrogen in at least one phenolic group in said salt.

5. A hydrocarbon fuel base containing a corrosive acid-forming. substance and blended with a small concentration of a salt constituted of at least two alkyl phenol radicals linked to a nitrogen atom in an amino radical through methylene groups with a base forming metal replacing hydrogen in at least a portion of phenolic hydroxy groups, said salt being present in an amount sufficient to suppress corrosiveness;

6. A composition as described in claim 5, in which said hydrocarbon fuel is a Diesel fuel oil.

7. A composition as described in claim 5, in which said hydrocarbon fuel is a heating oil.

8. A petroleum fuel oil containing in solution a small concentration of a salt constituted of a plurality of alkyl phenol radicals linked through methylene groups to a metalloid atom selected from the class consisting of nitrogen and phosphorus in a basic group with a base-forming metal replacing hydrogen in phenolic hydroxy groups of the alkyl phenol radicals.

9. A hydrocarbon gasoline base fuel containing a small amount of tetra-ethyl lead and a small concentration of salt constituted of a plurality of alkyl phenol radicals attached to a nitrogen atom through a methylene group linkage with barium replacing hydrogen in phenolic hydroxy groups of said alkyl phenol radicals, said salt being present in sufficient amount to protect the tetraethyl lead against deterioration by sunlight.

l0. The method of improving the stability of petroleum fuel oils which comprises blending therewith about 0.01% to 0.5% by weight of a metal salt produced by condensing an alkyl phenol-formaldehyde-halogen halide condensation product having the general formula in which R represents alkyl substituents of the phenol in the aromatic nucleus Ar, and X represents halogen, with a nitrogen base having the general formula HNRR", in which R and R" are selected from the class consisting of hydrogen and a hydrocarbon radical of the class of alkyl, aryl and cyclo alkyl, whereby a resinous product is formed having the general formula [RAr(Ol-I) CH2]N(Y)Z in which R. represents alkyl substituents of the .phenol in the aromatic nucleus Ar, and Y and Z are selected from the class consisting of the RAr(OH)CHz-group, hydrogen and a hydrocarbon radical of the class of alkyl, aryl, cyclo alkyl, and the like, and converting said resinous product to the corresponding base-forming metal salt by replacing the hydroxyl hydrogen atom of at least one phenolic hydroxyl group by a base-forming metal.

- formula mm'a", in which R and R" are selected from the class consisting of hydrogen and a hydrocarbon radical of the class of alkyl, aryl and cyclo alkyl, whereby a resinous product is formed having the general formula [RAr(OH) CHs-J-NiY) z in which R represents allgvl substituents of the phenol in the aromatic nucleus Ar, and Y and Z are selected from the class consisting of the RAr(0H) CHz-group, hydrogen and a hydrocarbon radical of the class'ofalkyl, aryl cyclo alkyl, and the like.

12. A hydrocarbon oil boiling within the range of 100 700 F., tending to deteriorate during storage, stabilized by having dissolved therein a small amount or a base forming metal salt of a resinous product having the general formula in which R represents alkyl substituents of the phenol in the aromatic nucleus Ar, the metal of said salt replacing a substantial amount of the hydrogen atoms in the aromatic hydroxy groups of said resinous product.

13. A motor fuel comprising a major proportion of cracked petroleum gasoline, about 3 cc. of-

tetraethyl lead per gallon and about .02-.05% of the barium salt of a resinous product having the general formula [CsH1':-CaH3(OH)CH2]zNH, the barium of said salt replacing a substantial amount of the hydrogen atoms in the phenolichydroxy groups or said resinous product.

JOHN C. ZIMMER. JONES I. WASSON.