US2445975A - Solubilized alkaryl sulfonate composition - Google Patents

Description

atented .luly 27, 19

Norman M. Shepard, Stamford, Conn,

to erican Cyanamid Gomp, New York, N. Y a corporation oil Maine No Drawing. Application May 8, 1946,

- do No. 66%,396

This invention relates to solubilized alkaryl sulfonate compositions such as the alkali metal or ammonium salts of alkyl naphthalene suli'onates, and mor particularly to compositions containing dicyandlamide as a solubilizing agent therefor.

The water-soluble salts of alkaryl sulfonates such as sodium isopropyl naphthalene sulfonate, sodium butyl naphthalene sulfonate and sodium heryl benzene sulfonate are in wide commercial use as wetting and emulsifying agents and as detergents. Large quantities of these and similar compounds are prepared in the form of aqueous solutions containing 10-20% of the allsaryl sulionic acid salt. It is a principal object of the present invention to soluhilize the alkaryl sulfonates in these solutions to prevent crystallization or deposition of the solute at low temperatures.

1 have found that dlcyandiamide is an unusually efi'cctive solubilizing agent for alkaryl sulfonlc acid salts of the type of isopropyl or hutyl naphthalene sulfonates and particularly for alkyl benzene sodium sulfonates wherein the alkyl radical contains about 19-15 carbon atoms. These allryl benzene sulionates are usually prepared by first chlorinating a fraction of kerosene which contains about 10-15 and preferably about 13 carbon atoms followed by condensing the chlorinated kerosene fraction with benzene in the presenc of a Friedel-Crait catalyst. The resulting alhyl benzene is sulionated with strong suliuric acid or other sul'lonatlng agent to produce the wetting agent. Typical compounds of this type are described in U. S. Patent No. 2,220,099.

The allryl naphthalene sulfonates are ordinarily prepared by condensing naphthalene beta sulfonic acid with isopropyl or loutyl alcohol in the presence at excess tree sulfuric acid, preferably under conditions such as to introduce about 1.5-2.5 alkyl groups per molecule of naphthalene. These compounds and their method of preparation are descrlhed in German Patent No. 336,558.

The exact quantity of dicyandiamide to be used as a stabilizing agent will depend on the concentration of the aliraryl sulfonate solution and on the um storage temperatures to which it is likely to be exposed. in general, however, less than about 2.5% of dicyandlamide, hased on the weight of the wetting agent solution, is satisfactory for most practical purposes.

The quantities of dicyandiamide that will stabilize a 16% aqueous solution of a sodium keryl henzene sulfonate, sold commercially as Nacconol NRSF," are given in the following table:

Gms. Dicyandismidc per 100 Gms. oi Cloud Point, Clear Point,

Solution C. C.

Approximately the same quantities of dicyandiamide can be used to prevent crystallization or deposition of a 15% sodium isopropyl naphthalene sulfonate solution at the same temperature.

It will thus be seen that the compositions oi my invention consist essentially of 10-20% water solutions of alkaryl sulfonic acid salts having wetting, detergent and emulsifying properties, stabilized against crystallization or deposition by the incorporation therein of small amounts of dicyandiaxnide on the order or 92-25%, based on the weight of the solution. These quantities oi dicyandiamide are much smaller than the amounts of urea or other solubilizing agents that have heretofore been necessary to obtain the same degree of stabilization.

What I claim is:

1. An aqueous 10-29% solution oi a Wetting agent selected from the group consisting of alhali metal and ammonium salts of allraryl sulfonates containing from 4 to 15 carbon atoms in the allryl radicals thereof, said solution being stabilized against deposition at low temperatures of about 7 C. to 0 C. by a content of 0.2% to 2.5% at dicyandiamide.

2. an aqueous 10-20% solution of a wett agent selected from the group consisting of metal and ammonium halts of keryl benzene sulionates stabilized against deposition at low temperatures of about 7 C. to 0 C. by a content of 02-25% of dicyandiamide.

noat REFENLES @IT The following references are of record in the file of this patent:

UNITED STATES PATENTS