US2697656A - Surface-active agents and oil compositions containing them - Google Patents

Description

United States Patent SURFACE-ACTIVE AGENTS AND OIL COMPOSI- TIONS CONTAINING THEM Richard D. Stayner and Robert A. Stayner, Berkeley,

No Drawing. Application December 22, 1951, Serial No. 262,996

Claims. (Cl. 52--0.5)

This invention relates to new and useful oil-soluble surface-active agents and compositions containing them. More particularly, this invention relates to oil-soluble surface-active agents of an ionic nature which contain both an ionic carboxyl group and a cationic quaternary ammonium group within the same molecule and to improved hydrocarbon oil compositions containing them.

In accordance with the present invention, it has been discovered that new and useful oil-soluble ampholytic surface-active agents having both cationic and anionic characteristics may be prepared by reacting a di-(alkylarylrnethylene)-alkanolamine, a di-(alkylarylmethylene)- alkylamine, an alkylarylmethylene dialkanolamine or an alkylarylmethylene dialkylamine with an alkali metal or alkaline earth salt or an alkyl ester of a monohalogenated aliphatic carboxylic acid. The novel products thus obtained may be illustrated by the following structural formula:

wherein at least one but not more than two of the groups R1, R2 and R3 are long-chain alkylarylmethylene groups having from 9 to 18 carbon atoms in each long-chain alkyl substituent, the remainder being members of the class consisting of short-chain alkyl and hydroxyalkyl groups containing from 1 to 7 carbon atoms and R4 is an alkylene group of from 1 to 7 carbon atoms.

The above compounds are generally useful as surfaceactive agents. They are oil-soluble and are useful in hydrocarbon oil compositions such as lubricating oils and fuel oils as dispersing agents and rust inhibitors. their unusual amphoIytic or ,amphoteric nature, these compounds combine some of the beneficial aspects of both r cationic and anionic surface-active agents.

According to the invention, the compounds as illustrated in the above structural formula contain at least one alkylaryl group, each of which is connected by a methylene linkage to the nitrogen. Examples of suitable aryl groups include benzene, naphthalene, anthracene, toluene, xylene, mesitylene, etc. with benzene and toluene being preferred for their availability and the high degree of effectiveness characteristic of the compounds containing them. The alkyl substituents on the aryl nucleus may be straight-chain or branched-chain in, nature and may vary from 9 to 18 carbon atoms in length. For present purposes propylene polymers containing from 9 to 18, and more specifically from 12 to 15, carbon atoms per mole cule are preferred because of their ready availability and their chemical stability derived, apparently, from the characteristically moderate chain-branching of the propylene polymers in general.

In the above structural formula illustrating the invention, the N-alkyl or N-hydroxyalkyl portion may be'con- Due to veniently derived from any primary alkyl or hydroxy.

.89 amine, butanolam ne, d meth ylarmne hydrochloride, d1-

2,697,656 Patented Dec. 21, 1954 ice isopropylamine hydrochloride, etc. Methylamine, dimethylamine, dimethylamine hydrochloride, ethylamine, ethanolamine and di-ethanolamine are presently preferred.

The nature of the alkylene group R4 in the structural formula is determined by the particular monohalogenated aliphatic carboxylic acid salt or ester employed in the preparation of the compounds according to the invention. Suitable halogenated acid salts or esters include sodium monochloroacetate, potassium monobromopropionate, sodium a-bromo n-butyrate, potassium a-bromo valerate, calcium iodoacetate, magnesium chloroacetate, methyl monochloroacetate, isopropyl monobromo-n-butyrate, etc. For their effectiveness and ready availability sodium monochloroacetate and methyl chloroacetate are presently preferred.

The N,N-di-(alkylbenzyl) and N-alkylbenzyl glycines constituting the preferred embodiment of the invention may be illustrated by the formula:

wherein R is a long-chain alkyl group of from 9 to 18 carbon atoms, R is a member of the group consisting of hydrogen and methyl, x is an integer of from 1 to 3 and R" is a member selected from the class consisting of methyl, ethyl and hydroxyethyl groups.

An important advantage of the present invention lies in the process whereby the above preferred group of compounds may be prepared. Suitable alkylbenzenes, alkyltoluenes, or alkylxylenes such as nonylbenzene, dodecylbenzene, dodecyltoluene, etc. may be chloromethylated by suitable means, as, for example, by reacting them with formaldehyde or para-formaldehyde and hydrogen chloride in the presence of a catalyst such as an anhydrous mixture of zinc chloride and acetic acid. The resulting alkylbenzyl chloride is a very stable and highly reactive intermediate which may be condensed with any of the aforementioned primary and secondary amines to produce the N,N di-(alkylbenzyl)- and N-alkylbenzyl tertiary amines used in the preparation of the compounds of this invention. It reacts much more cleanly with the primary and secondary amines than would the corresponding long-chain alkyl halides and the N,N-di-(alkylbenzyl)-.' and N-alkylbenzyl glycines derived from the resulting tertiary amines are remarkably free of undesirable by-products of side reactions.

The condensation of the alkylbenzyl chloride with the primary or secondary amine or amine salt to form the corresponding tertiary amines as referred to above may be carried out according to any suitable method known .to the art. For present purposes it is preferred that the alkylbenzyl chloride and amine be condensed with the aid of a mild neutralization agent, such as sodium bicarbonate, while warming the reaction mixture slightly, usually in the temperature range of from to 200 F.

The N,N-di-(alkylbenzyl)-N-alkanolor alkyl tertiary amines or N-alkylbenzyl-N,N-dialkanolor dialkyl tertiary amines resulting from the foregoing preparations may then be reacted with a suitable salt or ester of a monohalogenated aliphatic carboxylic acid of the type described above, such as, sodium monochloroacetate .or methyl chloroacetate, to form the oil-soluble ampholytic surface-active agents of this invention. If desired, the

reaction may be carried out in the presence of an inorganic iodide, such as potassium iodide, which acts as a promoter and the mixture may be warmed sli htly to a temperature in the ran e of from 100 to 200 F.

For convenience of handling, solvents for the above reaction mixtures may be employed. Suitable solvents Example I.Preparation of N,N-di-(dodecylbenzyl)- ethanolamine 140 parts of dodecylbenzyl chloride was added dropwise to a mixture of 15% parts of ethanolamine and 42 parts of sodium bicarbonate in an isopropanol-water solution. The addition was carried out over a period of one hour at a temperature of from 120 to 125 F. Following the addition, the stirred mixture was refluxed for two hours, filtered to remove inorganic salts and then diluted with mixed hexanes. The diluted solution was next washed with water, dried over anhydrous calcium sulfate and concentrated under reduced pressure to give 143 parts of N,N-di-(dodecylbenzyl)-ethanolamine in the form of yellow oil.

Example 2.Preparation of N,N-di-(ddecylbenzyl)- N-Z-hydroxyethyl glycine An isopropanol solution of 52 parts of N,N-di-(dodecylbenzyl)-ethanolamine prepared in Example 1 was refluxed with 13 parts of sodium chloroacetate and 3 parts of potassium iodide for 12 hours. The mixture was then filtered to remove inorganic salts and the solution washed with water and extracted with mixed hexanes. The mixed hexane solution was then evaporated under reduced pressure to give the N,N-di-(dodecylbenzyl)-N-2- hydroxyethyl glycine in the form of a viscous, yellow liquid.

Example 3.Preparation of N-nonylbenzyl-dz'ethanolamine The alcoholic portion was alkalized to pH 10.0 with per cent sodium hydroxide solution and the product extracted with 200 parts of mixed hexanes. The hexane solution was then washed with water and concentrated under reduced pressure to give 46 parts of N-nonylbenzyldiethanolamine as a viscous, yellow liquid. Analysis: per cent N (calc.)=4.37; per cent N (found)=4.11.

Example 4.--Preparati0n of N-nonylbenzyl-N,N-di-(2- hydroxyethyl) -glycz'ne A mixture of 41 parts of N-nonylbenzyl-diethanolamine (prepared in Example 3), 23 parts of methyl chloroacetate, 5 parts of potassium iodide and 100 parts of ethyl alcohol was stirred and refluxed for hours. A solution of 16 parts of sodium bicarbonate in 150 parts of water was added portionwise and the mixture was again refluxed for 3 hours. The pH was adjusted to 9.5 with caustic and the solution was refluxed two hours, cooled, diluted with 200 parts of methanol'and then extracted with mixed hexanes. The alcoholic portion was washed with water and the product concentrated under reduced pressure to give 24 parts of N-nonylbenzyl-N,N- di-(Lhydroxyethyl)-glycine as a yellow-colored, viscous liouid. Analvsis: per cent N (calc.)=3.70; per cent N (found)=3.68.

Example 5.Preparation of N-dodecylbenzyl-N,N- dimethylamine ture was refluxed two hours, filtered and acidified to pH 2.0 w th concentrated hydrochloric acid. The solution was extracted with two part portions of mixed hexanes and then alkalized to pH 8.5 with caustic solution. The product was taken up in mixed hexanes, washed with water, concentrated by evaporation of most of the solvent and then distilled collecting the fraction boiling at 266 to 293 F. at 2 mm. There was obtained 34 parts of N-dodecy1benzyl-N,N-dimethylamine as a colorless liquid.

Example 6.Preparati0n 0f N-dodecylbenzyl-N,N- dimethylglycine A stirred mixture of 4.7 parts of chloroacetic acid, 2.8 parts of potassium hydroxide and 100 parts of ethanol was warmed slowly to F. until the solution became clear, and then 3.1 parts of potassium iodide and 12.5 parts of N-dodecylbenzyl-N,N-dimethylamine (prepared in Example 5) were added. The mixture was stirred and refluxed for six hours, filtered and made alkaline with caustic. The alcoholic solution was washed first with two 100-part portions of mixed hexanes and then with two 100-part portions of water. The product was dissolved in 50 parts of benzene and then concentrated under reduced pressure to give 12 parts of N-dodecylbenzyl- N,N-dirnethylglycine as a colorless grease. Analysis: per cent N (ca1c.)=3.75; (found)=3.50.

The proportions given in the foregoing examples are on a weight basis unless otherwise specified.

' As mentioned above, the present invention is also concerned with the preparation of improved hydrocarbon fuels and, more particularly, with hydrocarbon fuels having improved properties as burner, diesel and jet fuels.

In the production of burner fuels, diesel and jet fuels, it is desirable, economically, to employ considerable quantities of cracked refinery stocks. Such stocks are becoming more and more available due to the everincreasing use of thermal and catalytic cracking processes in petroleum refinery operations. When employed in burner fuels and diesel and jet fuels, these stocks have the disadvantage of forming particles of sludge or gum which tend to deposit and cause plugging of filters, screens and lines. The necessity for frequent interruptions of burner and diesel engine service to replace or unplug clogged filters and screens constitutes a serious problem.

Burner, diesel and jet fuel systems ordinarily contain certain amounts of water due to vapor condensation. The presence of this water tends to accelerate the formation of filter plugging gum and sludge in such fuels, particularly those containing cracking stocks, and also cause rusting of exposed ferrous metal surfaces which ust in turn eventually loosens and clogs the filters and mes.

As part of the present inventionit has been discovered that by the addition of a small amount of an oil-soluble ampholytic surface-active agent of the type described above to normally liquid hydrocarbon fuels, anv tendency of the fuel to form filter clogging particles of sludge or gum is substantially overcome. Such hydrocarbon fuel compositions, in addition, have the effect of inhibiting rusting of ferrous metal surfaces with which they come in contact, thus substantially eliminating rust particles that may also lead to clogging of fuel oil systems.

The hydrocarbon fuel base stocks suitable for use in the improved fuel oil compositions of the present invention may be described broadly as petroleum distillates b i ing in the ran e of from about 350 F. to about 750 F. Such distillates are ordinarily characterized by an APT ravity of at least 20 degrees and usuallv at least 25 de rees. The base stocks may be either straightrun distillates or cracked distillates. The present invention finds its greatest utility in hydrocarbon fuels of the preceding tvoes which contain substantial amounts of cracked distillates. Without the additives of this invention, such fuels form ap reciable amounts of filter plugging sludge and gum which render them unsuitable for use in operations where interrupted service is desired, as is the case with most present-day operations.

Very small amounts of the additives, in the order of 1% by weight or less, have been found to be entirely effective for a prevention of line and filter clogging and also the inhibition of rusting when Water is present in the system. Amounts in the range of from 0.001 to 0.20% by weight of the total fuel are particularly suitable and proportions in the range of from 0.005 to 0.015% by weight are most preferred in the more specific embodiments of the invention.

s .-In order to facilitate'evaluation of the improved fuel oil compositions of the present'invention and avoid an enormous outlay of time and material, a rapid test method for determining filter plugging characteristics was developed. The results of this test method have been found to correlate well with actual field tests, using regular fuel oil burners and diesel and jet engines. The test is carried out by mixing 500 milliliters of a fuel composition containing 0.01% by weight of additive with 500 milliliters of water containing 102 parts per million hardness calculated as calcium and magnesium carbonates, two-thirds being calcium carbonate. The fuel oil composition and water are shaken in a separatory funnel for 30 seconds, at the end of which they are allowed to. stand for minutes. At this point a phase separation occurs and an upper oil layer and a-lower water layer are obtained, usually separated by an opaque cutf attheir interface. This interface cuff is then filtered through a fritted glass crucible with the aid of a vacuum. Only as much oil and water are filtered as are necessary to assure complete extraction of the cuff, usually about milliliters. However, in cases of severe emulsions the entire content of the separatory funnel may have to be filtered. The resultant discoloration of the crucible mat by the particles of gum and sludge deposited is used as a comparative measure of the hydrocarbon fuels tendency to plug filters and screens.

In the comparison, the filter is compared with a standard series of 11 filters prepared in a similar manner from fuels of known filter-plugging tendency. The standard filters are numbered 0 to 10, the higher numbers being identified with the higher deposits. For convenience, the rating given a particular test sample is termed its Interface Filter Deposit Rating (IFD) and denotes the number of the filter in the standard series with which it compares in amount of filter deposit.

Table I, which follows, shows the IFD values of a number of fuel oil compositions according to the present invention as compared with a standard diesel, burner or jet fuel. The base fuel employed in each case was a mixture of equal parts of straight run distillate from a waxy base crude boiling in the range of from 384 F. to 675 F. and a Thermofor catalytic cracked fraction boiling in the range of from 376 F. to 566 F.

The data in Table I above clearly shows the marked superiority of the improved hydrocarbon fuel compositions according to the present invention over a conventional diesel, jet or burner fuel. Run 1 shows that no filter deposit is obtained from fuel oil compositions containing a representative agent, whereas the fuel oil base stock itself gives an extremely high filter deposit.

The fuel oil compositions of the present invention were also tested for their rust-inhibiting properties. The tests were carried out in accordance with the procedure outlined in ASTM method D665-47T. Steel spindles were immerged in an agitated distilled water and fuel oil mixture containing 0.001% by weight of additive and in an agitated sea water and fuel oil mixture containing 0.005% by weight of additive. The base stock fuel was tested in a similar fashion. The results of these tests are as From the above tests it will be readily observed that the improved fuel oil compositions of this invention p'ossess remarkable rust-inhibiting properties as compared to ordinary diesel, jet or burner fuels.

The fuel oil compositions according to the present invention may also contain other fuel oil additives in addition to the oil-soluble ampholytic surface-active agents of this invention. Such additives include: lecithin; oil-soluble alkylaryl polyglycol ethers such as didodecylphenyl-dodecaethylene glycol ether; oil-soluble sulfonates such as the lead salts of petroleum sulfonic acids containing from about 20 to 30 carbon atoms per molecule; oil-soluble naphthenates such as the alkali metal and lead salts of petroleum naphthenic acids; alaali metal and lead salts of alkylphenyl disulfides.

We claim:

1. Oil-soluble surface active compounds having the formula:

wherein at least one but not more than two of the groups R1, R and R are long-chain alkylbenzyl groups having a long-chain alkyl substituent on each benzene nucleus containing from 9 to 18 carbon atoms, the remainder being members of the class consisting of short-chain alkyl and hydroxyalkyl groups containing from 1 to 7 carbon atoms.

2. Oil-soluble surface active N,N-di-(alkylbenzyl)-N- alkanol glycines having a long-chain alkyl substituent on each benzene nucleus containing from 9 to 18 carbon atoms and an alkanol substituent on the nitrogen containing from 1 to 7 carbon atoms.

3. Oil-soluble surface active N,N-di-(alkylbenzyl)-N- alkyl glycines having a long-chain alkyl substituent on each benzene nucleus containing from 9 to 18 carbon atoms and an alkyl substituent on the nitrogen containing from 1 to 7 carbon atoms.

4. Oil-soluble surface active N-alkylbenzyl-N,N-dialkanol glycines having a long-chain alkyl substituent on the benzene nucleus containing from 9 to 18 carbon atoms and alkanol substituents on the nitrogen containing from 1 to 7 carbon atoms each.

5. N,N-di-(dodecylbenzyl)-N-methyl glycine.

6. N-dodecylbenzyl-N,N-di-Z-hydroxyethyl glycine.

7. N,N-di-(dodecylbenzyl)-N-2-hydroxyethyl glycine.

8. A process which comprises heating at a temperature between about and 200 F. 2 molar proportions of an alkylbenzyl chloride having from 9 to 18 carbon atoms in the alkyl portion thereof with 1 molar proportion of ethanolamine in the presence of sodium bicarbonate, heating at a temperature between about 100 and 200 F. the N,N-di-(alkylbenzyl)-ethanolamine thus obtained with sodium monochloroacetate in the presence of potassium iodide to give an oil-soluble, surface-active N,N-di-(alkylbenzyl)-N-2-hydroxyethyl glycine having a long-chain alkyl substituent on each benzene nucleus containing from 9 to 18 carbon atoms.

9. A hydrocarbon oil composition containing a small amount suflicient to inhibit line and filter clogging and corrosion of a compound having the following formula:

wherein at least one but not more than two of the groups R1, R2 and R3 are long-chain alkylbenzyl groups having a long-chain alkyl substituent on each benzene nucleus containing from 9 to 18 carbon atoms, the remainder being members of the class consisting of short-chain alkyl and hydroxyalkyl groups containing from 1 to 7 carbon atoms.

10. A hydrocarbon fuel oil composition comprising a major proportion of a normally liquid hydrocarbon fuel oil and a small amount sufiicient to inhibit line and filter clogging and corrosion of an N,N-di-(alkylbenzyl)-N- alkanol glycine having a long-chain alkyl substituent on each benzene nucleus containing from 9 to 18 carbon atoms and an alkanol substituent on the nitrogen containing from 1 to 7 carbon atoms.

11. A hydrocarbon fuel oil composition comprising a major proportion of a normally liquid hydrocarbon fuel oil and a small amount sufficient to inhibit line and filter clogging and corrosion of an N-alkylbenz yl-N,N-dialka- 1101 glycine having a long-chain alkyl substituent on the benzene containing from 9 to 18 carbon atoms and alkanol substituents on the nitrogen containing from 1 to 7 carbon atoms each.

12. A hydrocarbon fuel oil composition comprising a major proportion of a normally liquid hydrocarbon fuel oil and a small amount sufiicient to inhibit line and filter clogging and corrosion of an N,N-di-(alky1benzyl)- N-alkyl glycine having a long-chain alkyl substituent on each benzene nucleus and containing from 9 to 18 carbon atoms and an alkyl substituent on the nitrogen containing from 1 to 7 carbon atoms.

13. A hydrocarbon fuel oil composition comprising a major proportion of a normally liquid hydrocarbon fuel oil boiling in the range of from about 350 F. to about 750 F. and a small amount not exceeding 1% by weight of N,N-di-(dodecylbenzyl)-N-methyl glycine, said fuel oil containing a substantial proportion of cracked petroleum distillate.

14. A hydrocarbon fuel oil composition comprising a major proportion of a normally liquid hydrocarbon fuel oil boiling in the range of from about 350 F. to about 750 F. and a small amount not exceeding 1% by weight of N,N di (dodecylbenzyl)-N-2-hydroxyethyl glycine,

' 8 said 'fuel oil containing a substantial proportion of cracked petroleum distillate.

15. A hydrocarbon fuel oil composition comprising a major proportion of a normally liquid hydrocarbon fuel oil boiling in the range of from about 350 F. to about 750 F. and a small amount not exceeding 1% by weight of N-dodecylbenzyl-N,N-di-Z-hydroxyethyl glycine, said fuel oil containing a substantial proportion of cracked petroleum distillate.

Claims (1)

1. OIL-SOLUBLE SURFACE ACTIVE COMPOUNDS HAVING THE FORMULA: