US 3846481 A
Salt of aromatic carboxylic acid and di-(n-octadecyl)amine as new composition of matter and the use thereof as pour point depressant in hydrocarbon oils. Also included is the use of a mixture of the salt with salt of aliphatic carboxylic acid and di-(n-octadecyl)amine.
Description (OCR text may contain errors)
United States Patent [191 Gaydasch Nov. 5, 1974 I ARYL CARBOXYLIC ACID SALTS OF DI(N-OCTADECYL)AMINE  Inventor: Alexander Gaydasch, Chicago, Ill.  Assignee: Universal 011 Products Company, Des Plaines, Ill.
 Filed: Aug. 28, 1972  App]. No.: 284,393
 US. Cl 260/50l.1, 252/77, 252/50, 44/71, 208/14  Int. Cl. C070 87/123  Field of Search 260/501.l
[5 6] References Cited UNITED STATES PATENTS 2,900,411 8/1959 Harwood et al. 260/501.1
FOREIGN PATENTS OR APPLICATIONS 1,138,296 9/1965 Germany OTHER PUBLICATIONS Primary Examiner-Bernard Helfin Assistant Examiner-Michael W. Glynn Attorney, Agent, or Firm-James R. I-loatson, Jr.;
BCKQQLQL- ram raiy ll am. Hikes II [5 7] ABSTRACT Salt of aromatic carboxylic acid and di-(noctadecyl)amine as new composition of matter and the use thereof as pour point depressant in hydrocarbon oils. Also included is the use of a mixture of the salt with .salt of aliphatic carboxylic acid and di-(n-,
4 Claims, No Drawings ARYL CARBOXYLIC ACID SALTS OF DI(N-OCTADECYL)AMINE BACKGROUND OF THE INVENTION The problems associated with the loss of fluidity of hydrocarbon oils at low temperatures are of considerable concern. Such loss of fluidity interferes with the satisfactory storing and transporting of the oil, as well as in mixing or blending of different oil fractions and in filtering operations. This problem is of increasing concern with the discovery of oil in subarctic areas, with the use of jet fuels at altitudes where temperatures of -50F. or lower may be encountered, etc.
Such hydrocarbon oils are sometimes referred to as heavier oils and contain components which, upon encountering low temperatures, crystallize to form solid precipitates. These crystals become active centers for further crystallization, with the result that the oil congeals and loses its free flowing properties. The oils are DESCRIPTION OF THE INVENTION The novel composition of matter of the present invention appears to be unique in two respects. In the first place, to the best of applicants knowledge, it has not been proposed heretofore to use a salt of an aromatic carboxylic acid as a pour point depressant. Furthermore, the di-(n-octadecyl)amine appears to be unique in forming salts which are of higher potency for such use.
As hereinbefore set forth, the novel composition of the present invention is a salt of aromatic carboxylic acid and di-(n-octadecyl)amine. In the aromatic carboxylic acid, the aliphatic moiety containing the carboxylic acid grouping, hereinafter referred to as carboxylic acid moiety, may contain from 1 to 26 or more carbon atomsbut preferably contains from 1 to carbon atoms. Although the aromatic moiety may comprise naphthyl, anthracyl, etc., it preferably comprises phenylalkyl. A preferred aromatic carboxylic acid in this embodiment is benzoic acid. Other preferred aromatic carboxylic acids include those wherein the alkylcarboxylic moiety contains 2-26 carbon atoms, such as phenylacetic acid, phenylpropionic acid, phenylbutyric acid, phenylpentanoic acid, phenylhexanoic acid, phenylheptanoic acid, phenyloctanoic acid, phenylnonanoic acid and phenyldecanoic acid. Still other acids include phenyldodecanoic, phenyltetradecanoic, phenylhexadecanoic, phenyloctadecanoic, phenyleicosanic and phenyldocosanoic acids.
The carboxylic acid moiety may contain a hydroxy group, an alkoxy group, or it may be part of an ester. The hydroxy carboxylic acids include phenyl hydroxy carboxylic acids having a hydroxyalkyl of from 3 to 26 carbon atoms.
The phenyl or other aryl ring or rings may contain one or-more substituents attached thereto including alkyl of l to 12 or more carbon atoms, alkoxy containing from 1 to 12 carbon atoms, hydroxy, carbamyl, car- 2 balkyloxy, amido, amino alkyl, halogen and particularly chlorine and bromine. When one substituent is present, it preferably is in a position para to the carboxylic acid moiety. When two ormore substituents are present, they preferably are in a position 3,4 or 3,5 on the phenyl nucleus. Illustrative examples in this embodiment include meta or para toluic acid, meta or para chlorobenzoic acid, meta or para bromobenzoic acid, meta or para hydroxybenzoic acid, anisic acid, gallic acid, etc.
As hereinbefore set forth, the novel compound of the present invention is a di-(n-octadecyl)amine salt of the aromatic carboxylic acid. While the pure amine may be prepared through extensive and expensive process of purification, for economical reasons it is preferred to use the commercially available hydrogenated N,N- ditallowamine as the source of di-(n-octadecyl)amine. The hydrogenated ditallowamine comprises primarily alkyl groups (up to 96 percent) of 18 carbons atoms each, although they may contain a minor amount of alkyl groups containing 14, 16 and 20 carbon atoms each. One such hydrogenated N,N-ditallowamine is available commercially under the trade name Armeen ZHT.
The salt is prepared in any suitable manner and generally by intimately mixing the amine and acid under conditions to avoid conversion to amide, ester or other condensation products. In a preferred embodiment, substantially equal molar proportions of the amine and acid are used. However, when desired, an excess of the amine may be employed, in which case the proportions may be in the range of from about 1.0 to about 1.2 mole proportions of amine per mole proportion of acid. In one method the reactants are admixed and stirred in the absence of a solvent, in which case it is preferred to warm one or both of the reactants, especially when solid at room temperature. For example, hydrogenated N,N-ditallowamine and benzoic acid are both solid at room temperature and preferably are warmed to a temperature of from about to about 200 F. for ease of handling and reacting. In another method, the salt is formed in the presence of a suitable solvent. Suitable solvents include aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, cumene or mixtures thereof, paraffinic hydrocarbons as hexane, heptane, octane, nonane, decane, undecane, dodecane, etc., or a mixture thereof, or a mixture of aromatic, paraffinic and/or naphthenic hydrocarbons as, for example, in naphtha, kerosene, light fuel oil, diesel oil, Vaseline, lubricating oil, or other suitable mixtures. In still another method, the solvent is an alcohol, ketone, nonylphenols, etc. or a combination of the solvents mentioned.
The amine and acid are intimately stirred at a temperature of from about 100 to about F. although the temperature may be up to about 200 F. For economical reasons, the temperature of heating will be as low as required for the convenient handling and mixing of the reactants to obtain a homogeneous solution, uniform suspension or a paste. The time of mixing will be sufficient to insure complete reaction and may range from 15 minutes to 1 hour or more.
In most cases, the final product will comprise substantially 100 percent by weight of the salt. However, when an excess of amine is employed, the product will contain unreacted amine. When the salt is prepared under a relatively high temperature, the product also may contain a minor amount of amide, ester or both.
The salt may be utilized as such, although generally it is preferred to utilize the salt as a suspension, paste or a solution in a suitable solvent for ease in handling, measuring and incorporating in the substrate. Any suitable solvent may be employed and advantageously is selected from the solvents hereinbefore set forth.
Illustrative but not limiting examples of salts comprised in the present invention include salts of di-(noctadecyl)amine salts of preferably hydrogenated ditallowamine, the economical source of di-(noctadecyl)amine with benzoic acid (also named dioctadecylammoniumbenzoate or hydrogenated ditallowammoniumbenzoate), toluic acid, p-
chlorobenzoic acid, p-bromobenzoic acid, phydroxybenzoic acid, anisic acid, phenylacetic acid, phenylpropionic acid, phenylbutyric acid, phenylpentanoic acid, phenylstearic acid, phenylhexanoic acid, naphthoic acid, anthroic acid, etc.
As hereinbefore set forth, the dioctadecylamine salt of aromatic carboxylic acid is believed to be a new composition of matter. This salt is an effective additive for use in depressing the pour point of hydrocarbon oils. Also as hereinbefore set forth, the di-(noctadecyl)amine'salt of the aromatic carboxylic acid has not been proposed heretofore for such use. The di- (n-octadecyl)amine salt of the aromatic carboxylic acid appears to offer advantages for such use as previously set'forth.
The hydrocarbon oils which are improved by the addition of pour point depressants may be classified as those having pour points of above about F. The oil may have an initial boiling point as low as 175 F. and end boiling point of above 1,000 F. under vacuum or practically not distillable but, as hereinbefore set forth, contains components which are responsible for the loss of fluidity. Illustrative examples of such oils include middle distillates, specialty oils, lubricating oils, residual oils, crude oils, etc. These oils may be untreated or resulting from conventional fractionation, solvent extraction, caustic treating, acid treating, dewaxing, desulfurizing, thermal cracking, catalytic cracking, reforming or other processing operations, etc. The middle distillates include oils within the boiling range of from about 250 to 750 F. and include kerosene, jet fuel, diesel oil, burner oil, gas oil, fuel oil, light cycle oil, specialty oils such as solvent oils, cleaning oils for use in cleaning metallic equipment, electrical insulating oil which is used in transformers or circuit breakers. hydraulic oils, etc. The lubricating oils may be conventional lubricating oils having boiling points, for example, within the range of 650 to 1050 F. or more or selected fractions thereof for special uses. The residual oils may result from fractionation to remove lower boiling compcnentsor heavier oils resulting from processing operations and may have initial boiling points of 600 F. or more. As mentioned earlier, problems are encountered in the transportation and storage of crude oils and reduced crude oils at low temperatures and especially in cold climates.
Different hydrocarbon oils respond differently to additives. Accordingly, as will be shown in the appended examples, some oils show a good response to the di-(noctadecyl)amine salt of the aromatic carboxylic acid in lowering the pour point of the oil. With other oils a mixture of the -di-(n-octadecyl)amine salt of aromatic carboxylic acid and the di-(n-octadecyl)amine salt of aliphatic carboxylic acid is more effective as synergistic mixtures in lowering the pour point of the oils. In general, the aliphatic carboxylic acid contains from i to 26 and preferably from l to 10 carbon atoms. These aliphatic carboxylic acids may be selected from the aliphatic carboxylic acids hereinbefore set forth and are not repeated herein in the interest of brevity. The di-(noctadecyl)amine salt of the aliphatic carboxylic acid is prepared in substantially the same manner as described for the preparation of the di-(n-octadecyl)amine salt of the aromatic carboxylic acid. The aromatic acid salt and the aliphatic acid salt will be used in suitable proportions, preferably containing at least 40 percent by weight of the aromatic carboxylic acid salt. Accordingly, these proportions may comprise from 40 to percent by weight of the aromatic carboxylic acid salt and from 5 to 60 percent by weight of the aliphatic acid salt. It is understood that mixtures of the aromatic carboxylic acid salts and/or of the aliphatic carboxylic acid salts may be utilized.
The di-(n-octadecyl)amine salt of aromatic carboxylic acid or of the mixture of salts is incorporated in the oil in a sufficient concentration to lower the pour point of the oil to a satisfactory degree. For economical reasons, the additive is used in as low a concentration as is satisfactory for the purpose and may be within the range of from about 0.001 to about 1 percent but generally is within the range of from about 0.005 to about 0.1 percent by weight of the oil. It is understood that the pour point depressant may be used in conjunction with other additives normally incorporated in the hydrocarbon oil, which will vary with the particular hydrocarbon oil and may comprise one or more of antioxidant, corrosion or rust inhibitor, viscosity index improver, cetane improver, metal deactivator, dye, etc.
The following examples are introduced to illustrate further the novelty and utility of the present invention but not with the intention of unduly limiting the same.
EXAMPLE I The salt of this example is the hydrogenated ditallowamine salt of benzoic acid which is the source of dioctadecylammoniumbenzoate. As hereinbefore set forth, the hydrogenated ditallowamine is available commercially under the trade name of Armeen 2HT and comprises principally C alkyl groups.
The salt was prepared by commingling 6.1 g. (0.05 mole) of benzoic and 25.15 g. (0.05 mole) of Armeen 2l-lT. The mixture was warmed to -195 F. and stirred to form the salt, with the resultant production of a clear liquid. The liquid was poured over aluminum foil in thin layer and allowed to solidify at room temperature as an ivory colored product, having a melting point of 132.8-134.6 F. The salt then was broken into small pieces and stored for use.
EXAMPLE I! Other hydrogenated ditallowamine salts of aromatic carboxylic acids are prepared in substantially the same manner as described in Example 1 except that different aromatic carboxylic acids are used to give the salts as shown in the following table.
TABLE I Aromatic Carboxylic Acids Salts p-toluic acid hydrogenated ditallowamine salt of p-chlorobenzoic acid p-hydroxybenzoic acid anisic acid phenylacetic acid phenylpropionic acid phenylbutyric acid phenylvaleric acid phenylcaproic acid phenylcapric acid phenyllauric acid phenylstearic acid abietic type acids, as
present in tall oil After suitable mixing of the reactants, the salt is recovered for use as pour point depressant.
It is understood that the specific salts set forth above are illustrative only and that other aromatic carboxylic acids may be used in preparing the salts with di-(noctadecyl)amine-containing hydrogenated ditallowamine.
EXAMPLE III As hereinbefore set forth, in some oils a mixture of the salt of the aromatic carboxylic acid and of a salt of an aliphatic carboxylic acid, the amine in both instances being hydrogenated ditallowamine, gives improved pour point depression. In some oils the amine salt of aromatic carboxylic acid is of only very moderate benefit, but the mixture thereof with the amine salt of aliphatic carboxylic acid gives considerably better results. The exact reasons for the differences in response in different oils is not completely understood as it is the phenomenon of synerg'ism, but it is known that different oils do respond differently to specific additives.
Accordingly, mixtures of the di(n-octadecyl)amine salt of benzoic acid with dioctadecylaminc-containing hydrogenated ditallowamine salts of the following aliphatic carboxylic acids, in approximately equal weight proportions, will offer advantages in certain oils.
trialky lacetic acids, such as Versatic 911 crotonic acid butyric acid Z-ethylhexanoic acid oleic acid ricinoleic acid isostearic acid hydroxystearic acid dimerized polyunsaturated fatty acids (D-SO MEX,
It is understood that the specific salts set forth above are illustrative only and that other aliphatic carboxylic acids may be used in preparing the salt with di-(noctadecyl)amine. In many oils, the mixture will produce synergistic results. However, it is understood that the particular mixture will be selected with regard to the particular hydrocarbon oil in which it is to be used.
EXAMPLE IV In place of the aliphatic carboxylic acid salts for use in admixture with the aromatic carboxylic acid salts, naphthenic acid salts may be used. The naphthenic acids are cycloalkyl acids and are chemically related to the alkyl carboxylic acids. As an example, a mixture comprises substantially equal weight percents each of the dioctadecylamine salt of naphthoic acid and the di- (n-octadecyl)amine salt of cyclohexane carboxylic acid. In another mixture, the di-(n-octadecyl)amine salt of benzoic acid is used in place of the di-(noctadecyl)amine salt of naphthoic acidl In many cases, the naphthenic acids are available as mixtures of acids including one or more of cyclopentane carboxylic acid, cyclopentylacetic acid, cyclohexane carboxylic acid, alkyl and particularly methyl derivatives of these acids, etc. For economical reasons, the mixed naphthenic acids preferably are utilized to form the di-(noctadecyl)amine salts for subsequent admixture with the di-(n-octadecyl)amine salt of aromatic carboxylic acid.
EXAMPLE V EXAMPLE VI This example reports the results of using the di(noctadecyl)amine-containing hydrogenated ditallowamine salt of benzoic acid, prepared in substantially the same manner as described in Example I, as a pour point depressant in a commercial diesel fuel. The diesel fuel has a boiling range of 4966l5 F. and a pour point of 16 F. t
The pour points reported in this and the following examples were determined in an Autopour instrument. The pour point is determined by the automatic recording of a temperature at which a 5/8 inch plastic discus immersed to a depth of /s inch in the oil sample, could not be turned a few degrees around its axis by preadjusted gentle twisting and swinging force. The oil sample is thermoelectrically cooled at a rate of 2 F. per minute, while a force to cause slight swing (like a pendulum) and a twist is applied every two minutes. The autopour gives better reproducible values than ASTM Method D-97 and appears to be receiving increasing acceptance in the petroleum industry.
In a sample of the diesel fuel to which 0.025 percent by weight of the di-(n-octadecyl)amine-containing hydrogenated ditallowamine salt of benzoic acid was added, the pour point of the oil was decreased from 16 F. to 44 F., thus showing a pour point depression of 60 F.
EXAMPLE VII The oil used in this example is a commercial highly aromatic light cycle oil having a boiling range of 358-709 F. and a pour point of 2 F. Upon the addition of 0.01 percent by weight of the di(n-octadecyl)amine-containing hydrogenated ditallowamine salt of benzoic acid, the pour point of the oil was decreased to less than 50 F., the temperature beyond which further cooling of the oil sample in the Autopour instrument becomes impractically lengthy.
EXAMPLE VIII .acid in a concentration of 100 ppm reduced the pour point to F., a decrease of only 1 F. However, a mixture of 100 ppm of the di-(n-octadecyl)amine salt of benzoic acid and 100 ppm of the di-(noctadecyl)amine salt of 2-ethylhexanoic acid decreased the pour point of the diesel fuel to -44 F., thus showing a pour point depression of 60 F.
The dioctadecylamine salt of isostearic acid, in a concentration of 100 ppm, reduced the pour point of the diesel fuel to 15 F., a depression of only 1 F. However, a mixture of 100 ppm of the di-(nocta decyl)amine salt of benzoic acid and 100 ppm of the di-(n-octadecyl)amine salt of isostearic acid served to reduce the pour point to 38 F. or a depression of 54 F. a
The di-(n-octadecyl)amine salts of naphthenic acid, in a concentration of 125 ppm, reduced the pour point of the diesel fuel to 15 F., a depression of only 1 F. However a mixture of 125 ppm of the di-(noctadecyl)amine salt of benzoic acid and 125 ppm of the di-(n-octadecyl)amine salt of the naphthenic acid reduced the pour point to F., a depression of 41 F The di-(n-octadecyl)amine salt of trialkylacetic acid (Versatic 911), in a concentration of 125 ppm did not reduce the pour point of the diesel fuel at all. However, a mixture of 125 ppm of the di-(n-octadecyl)amine of benzoic acid and 125 ppm of the di-(noctadecyl)amine salt of the trialkylacetic acid reduced the pour point to 46 F., thus showing a depression of 62 F.
From the above examples,'it has been seen that, in this particular diesel fuel, none of the amine salts in economically small amounts were either of no benefit or only of benefit to a very small degree. However, a mixture of the salt of an aromatic carboxylic acidand the salts of the alkyl carboxylic acids served to considerably lower the pour point of the diesel fuel.
EXAMPLE IX This example describes the use of a salt of the present invention in lubricating oil. The lubricating oil is neutral stock, having a viscosity at F. of 102 SUS and is of amber color. The oil has a pour point of 20 F. The incorporation therein of 0.25 percent by weight of the di-(n-octadecyl)amine salt of benzoic acid lowered the pour point to 34 F. for a depression of 54 F. At a concentration of 0.1 percent by weight the depression in pour point was 39 F.
EXAMPLE X The hydrocarbon oil used in this example is Arabian crude petroleum having a pour point of 1 8 F. The addition thereto of 0.05 percent by weight of the di-(noctadecyl)amine salt of benzoic acid lowered the pour point to 40 F., thus showing a depression in pour point of 22 F.
I claim as my invention:
1. A salt of di-(n-octadecyl)amine and a phenyl carboxylic acid selected from the group consisting of benzoic and phenylalkylcarboxylic acids wherein said alkylcarboxylic acid moiety contains from 2 to 26 carbon atoms.
2. The salt of claim 1 in which said alkyl carboxylic acid moiety contains from 1 to 10 carbon atoms.
3. The salt of claim 1 being di-(n-octadecyl)amine salt of benzoic acid;
4. A salt of hydrogenated ditallowamine and a phenyl carboxylic acid selected from the group consisting of benzoic and phenylalkylcarboxylic acids wherein said alkylcarboxylic acid moiety contains from 1 to 26 carbon atoms.