US2615847A - Alkaryl sulfonate detergents - Google Patents

Description

Patented Oct. 28, 1952 ALKARYL SULFONATE DETERGENTS Kenneth M. Thompson, Aidan, Pa., assignor to The Atlantic Refining Company, Philadelphia, Pa", a corporation of Pennsylvania No Drawing. Application January 27, 1950,

Serial No. 140,949

The present invention relates to alkylated aryl sulfonate detergents,'and relates more particu-' larly to the lowering of the cloud point and the improvement in color of aqueous solutions of alkylated aryl sulfonates.

j It has been common practice heretofore to manufacture and sell concentrated aqueous solutions of alkylated aryl sulfonates, the alkyl group of which contains from 9 to 15 carbon atoms, and preferably about 12 carbon atoms., These solutions usually contain inorganic salts such as sulfates of the alkali metals in minor amounts, which salts were produced in the course of manufacture of the sulfonates and were not removed from the final product. Depending upon the molecular weight of the alkyl group and the concentration of the sulfonates in the solution, the' solubility and hence the cloud point varies. With increase in molecular weight or with concentration, the cloud point likewise increases. 'Since it is desirable to ship the sulfonate solutions in as high a concentration as is possible while retaining homogeneity within a reasonable temperature range, handling difliculties occur when the temperature of the solution drops below the .cloud point, particularly over an extendedperiod of time. At temperatures below the cloud point, as determined by the A. S. T. M. MethodDQ'I-'l, the sulfonates tend to precipitate from aqueous solution, thus giving rise to non-uniformity of the solution. This is particularly troublesome in handling sulfonate solutions in bulk, i. e., transportation in tank cars or storage in unheated tanks.

In accordance with the present invention there is provided a method not only for overcoming the above difiioulty, but also for improving the color or the sulfonate products; Such method comprises adding to the alkylated aromatic hydrocarbon or hydrocarbon mixture in which the alkyl group contains from 9 to 15 carbon atoms, a minor amount of xylene, i. e., from 5% to 25% by volume, subjecting the mixture to sulfonation, and recovering the resulting mixed sulfonic acids, or their corresponding alkali metal, ammonium, or amine salts.

The xylene to be employed may be one or a mixture of the isomeric xylenes, commercially available xylenes in which the meta isomer predominates being preferred for economic reasons; The alkylated aromatic hydrocarbons containing known methods.

5 Claims. 7 (01. 252-461) from 9 to carbon atoms in the alkyl group may be produced by any one of a number of well- The aromatic hydrocarbon used is preferably benzene, although toluene, xylene, cumene, naphthalene, and the lower alkyl naphthalenes are also suitable for alkylation. Such alkylation may be accomplished by treating an excess of an aromatic hydrocarbon such as benzene with a halogenated aliphatic hydrocarbon of 9 to 15 carbon atoms in the presence of a suitable alkylation catalyst of the Frie'del-Crafts 2,387,572; and 2,469,378.

The alkylated benzene may also be produced by alkylating benzene with an alcohol or mono olefin of 9 to 15 carbon atoms, using sulfuric acid catalyst, or Friedel-Crafts catalysts as the case may be.

A further method for producing the alkyl benzene or mixture of alkyl benzenes having 9 to 15 carbons in the alkyl group is to polymerize an olefin such as propylene, or a gas stream con- Y taining propylene, with a supported phosphoric acid catalyst at elevated temperature and pressure, for example, 300 F. to 600 F. and 200 to 600 lbs/sq. in. pressure, thereby obtaining a mixture of 'propylenepolymers containing from 6 to 18 or more carbon atoms per molecule, and then fractionally distilling the mixture to separate a polymer fraction of desired boiling range or carbon atom content. Such fraction may comprise propylenepolymersof from 9 to 15 carbon atoms,,

or from 9 to 12 carbon atoms, or from 12 to 15 carbon atoms. Most desirable is a close out fraction averaging about12 carbon atoms. Benzene or other aromatic hydrocarbon is'then alkylated with the propylene polymer fraction in the presence of a'l riedel-Crafts cataly's't such as AlCla, ZnClz, l-IF, or with a sulfuric acidcatalyst to obtainan alkyl benzene or mixture of alkyl benzenes, which, if necessary, may be fractionally distilled to yield the, desired sulfonation stock.

Alkylation processes of this type are disclosed in United States'Patents Nos. 1,992,160; 2,232,118; 2,430,673;'2,477,382; and 2,477,383.

"Regardless of its method of production, the

alkyl benzene having an alkyl group of from 9 to 15 carbon atoms, ora mixture of alkyl benzene's withinthis'range; and preferably a mixture having an average of 12 carbons in the alkyl group, is then mixed with 5% to 25% by volume of xylene. Such mixture is then subjected to sulfonation with an agent such as sulfuric acid of 98% to 100% concentration, preferably at 150 F.160 FL, using about 1 volume of acid per volume of the alkyl benzene-xylene mixture. After the sulfonation is completed, the reaction mixture is diluted with a solvent such as benzene, and the spent sulfuric acid is settled out. the alkyl benzene sulfonic acids remaining in solution in the immiscible benzene layer. The benzene solution of sulfonic acids is then extracted with water or aqueous alcohol to dissolve and remove the sulfonic acids. The water or aqueous alcohol solution is separated from the benzene, neutralized with a suitable base such as aqueous sodium hydroxide, and the resulting sodium sulfonate solution is evaporated to remove water, or aqueous alcohol, and traces of benzene to give an aqueous solution of sulfonates of 30% to 50% concentration, and containing usually about to of inorganic salt, i. e., sodium sulfate. The sodium sulfonates comprise a mixture of the higher alkyl benzene sulfonates having from 9 to 15, and preferably about 12 carbon atoms in the alkyl group, together with the xylene sulfonate. higher alkyl benzenes and from 5% to 25% of xylene, it has been found that not only is the solubility of the ultimate sulfonate product substantially increased at high concentrations, but also the color of the product is improved. On the other hand, it has been found that when the higher alkyl benzenes are separately sulfonated, and the xylene is Separately sulfonated, and the resulting products are mixed, the solubility of the resultant product, as measured by cloud point, is not as great, and no color improvement is obtained. Moreover, the product resulting from the joint sulfonation of the mixture of higher alkyl benzenes and xylene shows no decrease in deters gency for W001 or cotton, and no decrease in foam, calcium ion tolerance, or increase in wet-, ting time and surface tension over that normally obtained from the higher alkyl benzene sulfonates, per se. In other words, the joint sulfonation of the higher alkyl benzenes and from 5% to 25% of xylene yields a product of improved solubility and color, and with no substantial change in the other properties common to the higher alkyl benzene sulfonates.

The present invention may be further illus. trated by the following examples, which, however, are not to be construed as limiting the scope thereof.

1. A gas stream comprising about 80% propylene, with minor amounts of propane, ethane, ethylene, and methane was contacted with a catalyst consisting of phosphoric acid impregnated on kieselguhr at 500 F. and 400 lbs/sq. in. pressure, at a rate of 0.1 lb. mole of propylene per lb. of catalyst per hour. ture of propylene polymers containing from 6 to 15 carbon atoms was fractionally distilled to remove an overhead fraction comprising primarily propylene dimers and trimers. The distillation residue or bottoms boiling between 340 F. and 550 F. and comprising mainly propylene tetramers with minor amounts of trimers and pentamers, was admixed with 6 molar equivalents of benzene, and the mixture treated with AlCh catalyst at 150 F.-160 F. to effect alkylation of the benzene with the propylene polymers. After removal of spent catalyst and treatment of the By sulfonating a mixture of The resulting mixcrude alkylate with caustic soda solution and with water, the crude alkylate was fractionally distilled to remove excess benzene and low boiling alkyl benzenes. The distillate residue or bottoms boiling between 450 F. and 680 F. and comprising for the most part a mixture of dodecyl benzenes, with minor amounts of lower and higher alkyl benzenes (nonyl, decyl, and pentadecyl benzenes) constituted the basic material for the preparation of the sulfonate detergents. A portion of basic material, i. e., alkyl benzenes averaging 12 carbons in the alkyl group, was set aside for the production of the corresponding sulfonate, while the remainder was mixed with varying percentages of xylene, i. e., 5%, 10%, 15%, and-20%, for the production of the mixed sulfonates.

In each case, ,1 volume of the hydrocarbons to be sulfonated was contacted with 1 volume of 98% concentration sulfuric acid at F.- F. for 35 minutes-to effect sulfonation. The sulfonat-ion reaction mixture was then diluted with 6 volumes pf benzene and permitted to settle and stratify into an upper layer comprising benzene containing the hydrocarbon sulfonic acids, and minor amounts of' unsulfonated hydrocarbons and entrained sulfuric acid. The lower layer consisted essentially of spent sulfuric acid, together with traces of benzene and unsulfonated hydrocarbon. After separation of the respective layers, the benzene solution of hydrocarbonsulfonic acids was mixed with'3 volumes of 40% methanol, and the mixture permitted to settle. The lower layer comprising aqueous methanol and the extracted sulfonic acids and traces of sulfuric acid was separated from, the upper benzene layer containing unsulfonated, hydrocarbon. The aqueous methanol solution was then neutralized with 25% concentration aqueous sodium hydroxide to a pH of about 3, washed with 3 volumes of benzen to remove traces of unsulfonated hydrocarbon, and the washed, partially neutralized aqueous methanol solution was finally neutralized with additional aqueous sodium hydroxide to a pH of 7 or slightly higher. The neutral solution of sulfonates was evaporated to remove water, methanol, and traces of benzene, giving an aqueous solution containing about 35%. of solids (85%. ofwhich was active sulfonate and 15% was inorganic salt, mostly sodium sulfate).

In order to show the effect of separately sulfonating xylene and then adding. the resulting sodium xylene sulfonate to the separately prepared basic material, 1. e., sodium dodecyl' benzene sulfonate, a quantity of xylene was sulfonated by conventional procedure and the sodium xylene sulfonate was added to give the equivalent of 5%, 10%, 15%, and 20% based upon 7 the dodecyl benzene sulfonate. The results with respect to cloud point and color are given in the following tables, the total solids concentration in the aqueous sulfonate solutions. being. 35% by weight.

Cloud Point of Solution, F.

Vol. PercentXylene- Y mint ssl i rfi ti n and-addition Color of Solution Separate sulfona- Joint sulfonation tion and addition Vol. Percent Xylene Lumino- NPA meter It is to be noted that in the Luminometer scale, color decreases with increase in numerical value, whereas in the NPA scale, color decreases with decrease in numerical value. From the above data it is apparent that joint sulfonation is superior to separate sulfonation and addition, both with respect to decrease in cloud point (or increase in solubility) and improvement in color. This efiect is even more noticeable with progressive increase in the solids concentration (sulfonate) from 35% to 50% by weight.

2. To a propylene polymer alkylated benzene having an average alkyl chain length of about 12 carbon atoms was added 15% by volume of commercial xylene, the mixture was sulfonated with 98% sulfuric acid, and the sodium sulfonates were recovered as an aqueous concentrate containing 55% solids. The concentrate was then diluted with water to successively lower concentrations and the cloud points were determined. The results are tabulated below. Of the solids content, active sodium sulfonate constituted 88.1% and inorganic salts 11.9%.

Percent Solids llfoint,

In lieu of xylene or mixtures of the xylenes, there may be employed ethyl benzene having the same molecular weight and the same number of alkyl carbon atoms. With ethyl benzene in amounts of to 25% by volume, much the same results are obtained as with xylene with respect to the lowering of cloud point of the higher alkyl aromatic sulfonates.

The detergents of the present invention may be marketed in the form of concentrated aqueous solutions containing from to 50% or more of solids. These solutions may be spray dried or drum dried to give solid detergents, or may be mixed with various amounts of alkali metal sulfates, phosphates, polyphosphates, silicates, or other materials and reduced to dry solids, if desired.

I claim:

ofk-afmono-alkylated aryl: hydrocarbon in which theialkyl: group contains'from 9 to' 15 carbonat'o'm'sand'. a quantity of an alkylated aryl hydrocarbon from'the groupconsisting of xylene and ethyl benzenefisuch'zthat vupon sulfonation and neutralization of the mixture, the salt of the sulfonicacid 'derivedfrom the last-mentioned alkylated arylhydrocarbon will constitute between 5% and 25% of the total salts ofthe sulfonic acids;and recover ing -the resulting sulfonic compounds from the sulfonation mixture.

2. A detergent comprising an aqueous solution of water soluble salts of alkylated aryl sulfonic acids and inorganic salts, the water soluble salts of the alkylated aryl sulfonic acids constituting a mixture of 95% to 75% of a water soluble salt of a mono-alkylated aryl sulfonic acid in which the alkyl group contains from 9 to 15 carbon atoms and 5% to 25% of a water soluble salt of an alkylated aryl sulfonic acid from the group consisting of salts of xylene sulfonic acid and salts of ethyl benzene sulfonic acid, said water soluble salts being prepared by subjecting to the action of a sulfonating agent a mixture of a mono-alkylated aryl hydrocarbon in which the alkyl group contains from 9 to 15 carbon atoms and a quantity of an alkylated aryl hydrocarbon from the group consisting of xylene and ethyl benzene, such that upon sulfonation and neutralization of the mixture, the salt of the sulfonic acid derived from the last-mentioned alkylated aryl hydrocarbon will constitute between 5% and 25% of the total salts of the sulfonic acids, and recovering the resulting sulfonic compounds from the sulfonation mixture.

3. A detergent composition in which the active ingredients comprise a mixture of 95% to 75% of a water soluble salt of a mono-alkylated benzene sulfonic acid in which the alkyl group contains from 9 to 15 carbon atoms and 5% to 25% of a water soluble salt of xylene sulfonic acid, said water soluble salts being prepared by subjecting to the action of'a sulfonating agent a mixture of a mono-alkylated benzene hydrocarbon in which the alkyl group contains from 9 to 15 carbon atoms, and a quantity of xylene such that upon sulfonation and neutralization of the mixture the l. A detergent in which the active ingredients comprise a mixture of 95% to of a water soluble salt of a mono-alkylated aryl sulfonic acid in which the alkyl group contains from 9 to 15 carbon atoms and 5% to 25% of a water soluble F to the action of a sulfonating agent a mixture 75 salts being prepared by subjecting to salt of the xylene sulfonic acid will constitute between 5% and 25% of the total salts of the sulfonic acids, and recovering the resulting sulfonic compounds from the sulfonation mixture.

4. A. detergent composition in which the active ingredients comprise a mixture of to 75% of a water soluble salt of a mono-alkylated benzene sulfonic acid in which the alkyl group contains from 9 to 15 carbon atoms and 5% to 25%,of a water soluble salt of ethyl benzene sulfonic acid, said water soluble salts being prepared by subjecting to the action of a sulfonating agent a mixture of a mono-alkylated benzene hydrocarbon in which the alkyl group contains from 9 to 15 carbon atoms, and a quantity of ethyl benzene such that upon sulfonation and neutralization of the mixture the salt of the ethyl benzene sulfonic acid will constitute between 5% and 25% of the total salts of the sulfonic acids, and recovering the resulting sulfonic compounds from the sulfonation mixture.

5. A detergent composition in which the active ingredients comprise a mixture of 95% to 75%01. water soluble salts of mono-alkylated benzene sulfonic acids in which the alkyl groups averag 12 carbon atoms, and 5% to 25% of a water solu ble salt of xylene sulfonic acid, said water soluble gill-2847; 7 of a'sul-fonatmg' agent a mixhlre of mono alkyb REFERENCES CITED med benzene hydrocarbons in which alkyl The following references are of record in the groups average 12 carb'on' atoms, and a; quantity of this patent: of xylene such that upon -sulfonailon and newtral-izatidn of the mixture, the salt 01 thexylen'e 5 UNITED STATES PATENTS sulfoniiz acid will constitute between 5% and Number Name Date 25% of the total salts of the sulfonic acids, and 1,944,367 Pott Jan. 23, 1934 recovering the resulting sulfonic'compaunds from 2,161,174- Kyriqles June 2, 1939 the sul-fonation mixturea 2,232,117 gyrides Feb. 18, 1941 THONIPSON. 10 2,298,696 Harris Oct. 13, 1942

Claims (1)

1. A DETERGENT IN WHICH THE ACTIVE INGREDIENTS COMPRISE A MIXTURE OF 95% TO 75% OF A WATER SOLUBLE SALT OF A MONO-ALKYLATED ARYL SULFONIC ACID IN WHICH THE ALKY GROUP CONTAINS FROM 9 TO 15 CARBON ATOMS AND 5% TO 25% OF A WATER SOLUBLE SALT OF AN ALKYLATED ARYL SULFONIC ACID FROM THE GROUP CONSISTING OF SALTS OF XYLENE SULFONIC ACID AND SALTS OF ETHYL BENZENE SULFONIC ACID, SAID WATER SOLUBLE SALTS BEING PREPARED BY SUBJECTING TO THE ACTION OF A SULFONATING AGENT A MIXTURE OF A MONO-ALKYLATED ARYL HYDROCARBON IN WHICH THE ALKYL GROUP CONTAINS FROM 9 TO 15 CARBON ATOMS AND A QUANTITY OF AN ALKYLATED ARYL HYDROCARBON FROM THE GROUP CONSISTING OF XYLENE AND ETHYL BENZENE, SUCH THAT UPON SULFONATION AND NEUTRALIZING OF THE MIXTURE, THE SALT OF THE SULFONIC ACID DERIVED FROM THE LAST-MENTIONED ALKYLATED ARYL HYDROCARBON WILL CONSTITUTE BETWEEN 5% AND 25% OF THE TOTAL SALTS OF THE SULFONIC ACIDS, AND RECOVERING THE RESULTING SULFONIC COMPOUNDS FROM THE SULFONATION MIXTURE.