2,979,521 United States Patent Office Patented Apr. 11, 1961 1 2 . Sulfuric acid monohydrate is H2SO4 or SOHO. The term "sulfuric acid monohydrate' identifies HSO and 2,979,521. excludes water in excess of the one mole combined with PREPARATION OF GLYCEROL SULFURIC ACDS the one mole of SO3 to form H2SO. Frederick William Gray, Belleville, N.J., assignor to Col . It is necessary at this point to define a few more terms gate-Pamolive Company, Jersey City, N.J., a corpor used in the specification and claims. ration of Delaware . The term "glycerol sulfuric acid' describes any of the glycerol mono-, di- and tri-sulfuric acids, and mixtures No Drawing. Original application Feb. 9, 1955, Ser. thereof. The degree of sulfation of such acids and No. 487,209, now Patent No. 2,868,812, dated Jan. O mixtures is indicated by a number between 0 and 3. 13, 1959. Divided and this application May 7, 1958, Thus, a degree of sulfation of 2.1 might indicate a mix Ser. No. 733,480 ture composed of glycerol di- and tri-sulfuric acids, or 7 Claims. (C. 260-458) more likely one of glycerol disulfuric acid with small amounts of the mono- and tri-sulfuric acids. The present invention relates to processes for the pro 5 "Non-gaseous sulfur trioxide' is the sulfur trioxide in duction of glycerol sulfuric acids. oleum or fuming sulfuric acid, which, if removed, would Included in the invention are methods of producing the leave sulfuric acid monohydrate. It is also liquid sulfur glycerol trisulfuric acid and glycerol sulfuric acid inter trioxide. The term does not include solid sulfur trioxide. mediate useful in the production of the trisulfuric acid. In manufacturing a monoglyceride sulfate detergent of These materials are of particular suitability for the pro 20 higher content of active detersive ingredient than that duction of monoglyceride sulfate detergents and deter generally produced one molecular proportion fatty tri gent intermediates from fatty triglycerides. glyceride, usually coconut oil, hydrogenated tallow or In subsequent descriptions, the words fatty triglyceride, hydrogenated soya oil, and preferably coconut oil, is glycerol trisulfuric acid and sulfuric acid monohydrate, reacted with a mixture of two molecular proportions of as used in the specification and claims have the following 25 glycerol trisulfuric acid and from 4.0 to 4.8, preferably meaning. from 4.2 to 4.6, molecular proportions, of sulfuric acid Fatty triglycerides are those whose acyl groups. aver monohydrate, at a temperature between 30 C. and age from 12 to 18 carbon atoms and are of a degree of 65 C., preferably with the final portion of the reaction unsaturation insufficient to substantially interfere with being conducted at a temperature between 50 C. and the manufacture of the detergent compositions described 30 65 C., to produce a detergent composition intermediate. in this application. Only a relatively small part of the In a preferred process the fatty triglyceride, preferably acyl groups present in such triglycerides may be of a coconut oil, is added, with agitation, within about ten to chain length outside the 12 to 18 carbon atom range. fifteen minutes to a mixture or solution of glycerol tri Such triglycerides are usually employed in the forms of sulfuric acid and/in sulfuric acid monohydrate at a tem coconut or palm kernel oils. However, tallows, greases, 35 perature between 30° C. and 45° C. (higher if the tri lard, cottonseed oil, soybean oil, palm oil and corn oil, glyceride is solid at those temperatures) after which the or fractions or mixtures of any thereof, may be used if reaction mixture is aged with agitation at from 50° C. they are first hydrogenated to remove undesirable unsatu to 65 C., desirably 50° C. to 60° C., for 2 to 2 hours, rated linkages. It is desirable that saturated triglycerides preferably 1 to 1/2 hours. If the reaction mixture is be employed, and since even coconut and palm kernel AO one that becomes excessively viscous a non-interfering oils contain some unsaturated triglycerides, it is some non-aqueous solvent, e.g., ethylene chloride, may be times preferable to hydrogenate these oils too before added to thin it and so enable the reaction to proceed reacting them according to the invented process. In this more readily. The speed of reaction may be increased specification, except for the examples given the term by increasing the degree of contact of the reactants, e.g., "coconut oil" is inclusive of hydrogenated, as well as 45 by improving mixing techniques, and consequently the non-hydrogenated coconut oil. mixing times may be correspondingly decreased. Glycerol trisulfuric acid, . Upon reacting the specified amounts of glycerol tri sulfuric acid, fatty triglyceride and sulfuric acid mono hydrate the following reaction is believed to occur. 50 O C-O-C-R is produced when glycerol is sulfated under proper con CH-OSOE ditions. The degrees of sulfation of glycerol sulfated by 2CH-OSOH --(40 to 4.8)HSO various methods have been determined by titration with 55 E-O-C-R cold sodium hydroxide, and it appears that to secure a C-OSOE O satisfactory detergent product from glycerol, fat and sul fation agent, one should first react the glycerol and sulfa ls. tion agent to produce glycerol trisulfuric acid free of CH-OSO3H CH-OSOE CH-OSOE glycerol mono- and di-sulfuric acids. The aforemen 60 &E-oson &H-osoir H-OSO tioned titration result indicates that the intermediate --(4.0 to 4.8)HSO necessary for the production of a satisfactory fatty acid l O " O O monoester of glycerol monosulfuric acid by the above Hi-o-R, E-05 R, Hi-or, method is glycerol trisulfuric acid and it is referred to as where R, R2, Rs are the same or different fatty radicals such. However it must be borne in mind that this term 65 of from 9 to 19 carbon atoms. The products of the is used to identify the product of processes described in above process, excluding the "monohydrate,” are here this specification. Therefore, should it be found that . after referred to as "disulfated monoacylated glycerol.” any of the products, made by the invented processes, in It is thought that the sulfuric acid is needed to split reality is not glycerol trisulfuric acid, the term never the fat and so aid the metathetic reaction, but this ex theless includes it. It also includes such product when 70 planation of the reaction mechanism is advanced only glycerol trisulfuric acid is called for as a reactant in one as a theory. of the described processes. On reaction with water, the -SOH group linked a,979,521 3 4. through oxygen to the carbon of the disulfated mono or basic aqueous media). However, when the neutraliza acylated glycerol is believed to be hydrolyzed off presum tion process is conducted in a circulating body of already ably, due to its proximity to the acyl group. neutralized material, which acts as a buffer, there is less The resulting compound, monoacylated monosulfated need for rapid neutralization. glycerol (probably with the substituent groups joined to In laboratory experiments detergent composition inter the glycerol terminal carbon atoms) is hereafter referred mediates, especially those derived from coconut oil, have to as “detergent acid.' The mixture of disulfated mono been "hydrolyzed' and neutralized by first plunging said acylated glycerol and sulfuric acid monohydrate in the detergent composition intermediate, made from one mol proportions resulting from the processes of this invention, ecular proportion of glycerol, into from about 200 to 400 is called "detergent composition intermediate.' These O molecular proportions of water at a temperature between terms are used to promote simplicity of expression. Since 0° C. and 50° C., and then neutralizing rapidly with a the identity of the various intermediate compounds has solution of a base, usually sodium hydroxide at an opera not been irrefutably ascertained, and since this invention tive weight concentration, between 20 and 60 percent in is of processes for making detergents and intermediates, the case of sodium hydroxide. Since the heat of dilution the terms used describe the products obtained from the 5 of the detergent composition intermediate is very great, invented processes. It is believed that such products are steps must be taken to prevent an undue temperature rise of the formulas given but the designations used in this when it is diluted. While in actual production it is the specification are not limited thereto. practice to dilute and neutralize in a circulating medium The hydrolysis referred to in a preceding paragraph of already neutralized material, in the laboratory or under may take place when the detergent composition interme 20 certain production conditions such methods are imprac diate is added to water or a water-ice mixture or when it ticable. Hence it is found necessary either to provide is treated with a base in the presence of water. Treatment refrigerated jackets on the processing vessel or, as is with a base will also result in a substitution of the base preferable in the laboratory, to use a mixture of ice and cation for the hydrogen of the remaining -SO3H group, liquid water, usually 2 parts ice and one part liquid water and will render the detergent water soluble. The splitting 25 as the diluting medium, allowing the temperature thereof off of the B-SO3H group and neutralization may also be to rise from 0° C. to approximately room temperature as conducted by adding the detergent composition interme the detergent composition intermediate is added. diate and base to a circulating stream of already neu The preceding descriptions of processes for the manu tralized detergent composition, thereby reducing local con facture of detergent composition intermediates and deter centrations of reactants and permitting the "hydrolysis' 30 gent compositions include the use of glycerol trisulfuric and neutralization to be conducted at a higher temperature acid containing minor amounts of sulfur trioxide (not with a consequent lower viscosity and higher practicable more than 12 parts per 100 parts by weight glycerol tri detergent composition solids concentration limit, while sulfuric acid).