HYDROGENATED OLEFIN SULFONATE DETERGENT BARS
United States Patent 3673122
Non-soap hydrogenated olefin sulfonate detergent toilet bars having improved slough loss and wear rate characteristics comprise a mixture of the sodium and magnesium salts of hydrogenated olefin sulfonates containing from 10 to 25 carbon atoms in a ratio of the sodium to the magnesium salt of 2:1 to 1:20 and a plasticizing amount of water.
US Patent References:
HEAT-TREATMENT OF SULFONATED OLEFIN PRODUCTS
Rubinfeld et al. - March 1970 - 3506580
TOILET BAR
Garrett - August 1970 - 3523089
Process for preparing beta-ethylenically unsaturated organic sulfonates
Broussalian - October 1967 - 3346629
HEAT-TREATMENT OF SULFONATED OLEFIN PRODUCTS
Rubinfeld et al. - March 1970 - 3506580
TOILET BAR
Garrett - August 1970 - 3523089
Process for preparing beta-ethylenically unsaturated organic sulfonates
Broussalian - October 1967 - 3346629
Application Number:
04/811153
Publication Date:
06/27/1972
Filing Date:
03/27/1969
View Patent Images:
Export Citation:
Assignee:
Chevron Research Company (San Francisco, CA)
Primary Class:
Other Classes:
510/498, 510/495
International Classes:
C07C303/32; C11D1/14; C11D17/00; C07C309/20; C07C303/00; C11D1/02; C07C309/00; C11D3/065; C11D1/12
Field of Search:
252/138,161,555,556 260/503
Primary Examiner:
Rosdol, Leon D.
Assistant Examiner:
Willis P. E.
Claims:
I claim
1. A non-soap detergent bar consisting essentially of
2. sulfonating straight-chain olefins containing from 10 to 24 carbon atoms with diluted SO3 at an SO3 :olefin mole ratio of 0.95 to 1.25,
3. neutralizing the product of (1) with at least one equivalent of base per mol of SO3 consumed in (1) and hydrolyzing the product of (1) at a temperature of between 100° and 200° C., and
4. hydrogenating from 50 to 100 percent of the unsaturated carbon-carbon double bonds in the product of (2),
5. A non-soap detergent bar as in claim 1 wherein the hydrogenated olefin sulfonates are hydrogenated α-olefin sulfonates.
6. A non-soap detergent bar as in claim 2 wherein the hydrogenated olefin sulfonates contain from 14-20 carbon atoms.
7. A non-soap detergent bar as in claim 3 wherein the hydrogenated olefin sulfonates contain from about 25-60 weight percent hydroxyalkane sulfonates and less than 20 weight percent of disulfonates.
1. A non-soap detergent bar consisting essentially of
2. sulfonating straight-chain olefins containing from 10 to 24 carbon atoms with diluted SO3 at an SO3 :olefin mole ratio of 0.95 to 1.25,
3. neutralizing the product of (1) with at least one equivalent of base per mol of SO3 consumed in (1) and hydrolyzing the product of (1) at a temperature of between 100° and 200° C., and
4. hydrogenating from 50 to 100 percent of the unsaturated carbon-carbon double bonds in the product of (2),
5. A non-soap detergent bar as in claim 1 wherein the hydrogenated olefin sulfonates are hydrogenated α-olefin sulfonates.
6. A non-soap detergent bar as in claim 2 wherein the hydrogenated olefin sulfonates contain from 14-20 carbon atoms.
7. A non-soap detergent bar as in claim 3 wherein the hydrogenated olefin sulfonates contain from about 25-60 weight percent hydroxyalkane sulfonates and less than 20 weight percent of disulfonates.
Description:
BACKGROUND OF THE INVENTION
The present invention is concerned with the field of synthetic non-soap detergent bars and, more particularly, with the preparation of bars or cakes for toilet or bath use from improved mixtures of hydrogenated olefin sulfonates.
Although synthetic detergents have largely replaced soaps for most household laundering and dishwashing uses, they have found little acceptance in the household toilet bar area. Although the detergent literature is replete with examples of synthetic detergent bars and synthetic detergent-soap combination bars, the toilet bar market continues to be dominated by soap bars. The combination bars have had appreciable acceptance but they exhibit the high pH characteristic of soap bars. At the present time, it appears that less than 1 percent of the bar market is satisfied by all synthetic detergent bars.
As disclosed in copending application, U.S. Ser. No. 748,188, filed July 29, 1968, it has been discovered that superior non-soap synthetic detergent bars can be formed employing hydrogenated linear olefin sulfonates as the major active detergent component. In particular, mixtures of straight-chain hydrogenated olefin sulfonates containing from 10 to 24 carbon atoms constitute a superior detergent component for non-soap detergent toilet bars. Although these hydrogenated olefin sulfonate bars comprise a significant advance over the non-soap detergent bars of the prior art, they are not as low in slough loss and wear rate as is desirable.
DESCRIPTION OF THE INVENTION
It has now been discovered that superior non-soap synthetic detergent bars low in slough loss and wear rate can be formed employing improved hydrogenated linear olefin sulfonates as the major active detergent component. In particular, mixtures of sodium and magnesium salts of straight-chain hydrogenated olefin sulfonates containing from 10 to 24 carbon atoms constitute a superior detergent component for non-soap detergent toilet bars. In general, when the ratio of sodium to magnesium salts is in a weight ratio of from 2:1 to 1:20, excellent slough loss and wear rate characteristics are exhibited with little or no appreciable effect on the other outstanding properties of hydrogenated olefin sulfonate detergent bars. Preferably, the ratio of sodium to magnesium salts is from 1:2 to 1:9.
The term "olefin sulfonates" as used in the present invention, defines the complex mixture obtained by the SO 3 sulfonation of straight-chain olefins containing 10 to 24 carbon atoms and subsequent neutralization and hydrolysis of the sulfonation reaction product. This complex mixture contains hydroxyalkane sulfonates and alkene sulfonates, as its major components, and a lesser proportion of disulfonated product.
While the general nature and the major components of the complex mixture is known, the specific identity and the relative proportions of the various hydroxy sulfonate and disulfonate radicals and double bond locations are unknown. Accordingly, a determination of the entire chemical makeup is exceedingly difficult and has not heretofore been successfully accomplished. The mixture is best defined by the process used for producing it.
Optimum detergent bar properties are exhibited by the composition obtained by hydrogenating an olefin sulfonate product which contains from about 25 to 75 percent by weight alkene sulfonates, from about 25 to 65 percent by weight hydroxyalkane sulfonates, and not more than 20 weight percent disulfonates. These optimum compositions are obtained by SO 3 -air sulfonation of C 10 -C 24 straight-chain olefins with SO 3 :air volume ratio of about 1:50-100 and an SO 3 :olefin mole ratio of 1.05-1.25:1, and neutralization and hydrolysis of the sulfonation reaction product at temperatures of 145°-250° C. using one equivalent of base per mole of SO 3 consumed in the sulfonation step.
In addition to the straight-chain α-olefins from wax cracking, suitable olefin starting materials include straight-chain α-olefins produced by Ziegler polymerization of ethylene, or internal straight-chain olefins prepared by catalytic dehydrogenation of normal paraffins or by chlorination-dehydrochlorination of normal paraffins. The olefins may contain from 10 to 24 carbon atoms, usually 13 to 22 carbon atoms, preferably 14 to 20, and more preferably 15 to 18 carbon atoms per molecule. Olefin mixture should have an average molecular weight of at least about 200.
The amount of SO 3 utilized in the sulfonation reaction may be varied but is usually within the range of 0.95 to 1.35 moles of SO 3 per mole of olefin and, preferably, in the range 1.05-1.25:1. Greater formation of disulfonated products is observed at higher SO 3 :olefin ratios. Disulfonation may be reduced by carrying the sulfonation reaction only to partial conversion of the olefin; for example, by using SO 3 :olefin ratios of less than 1 and removing the unreacted olefins by a deoiling process. The unreacted olefins may be removed by extracting the reaction product with a hydrocarbon such as pentane.
In order to obtain a product of good color, the SO 3 employed in the sulfonation reaction is generally mixed with an inert diluent or with a modifying agent. Inert diluents which are satisfactory for this purpose include air, nitrogen, SO 2 , dichloromethane, etc. The volume ratio of SO 3 to diluent is usually within the range of 1:100 to 1:1.
The reaction product from the sulfonation step step may be neutralized with aqueous basic solutions containing the sodium or magnesium hydroxides, carbonates or oxides. In the preferred method, sufficient neutralizing solution may be added to provide for neutralization of the sulfonic acids formed by sultone hydrolysis. Generally, one equivalent of base for each mole of SO 3 consumed in the sulfonation reaction is added to the sulfonation reaction product. The proportion of hydroxyalkane sulfonates to alkene sulfonates in the hydrolyzed neutralized product may be varied somewhat by the manner in which neutralization and hydrolysis are carried out. Thus, reduced amounts of hydroxyalkane sulfonates are obtained by carrying out the neutralization and hydrolysis at temperatures in the range of 145°-200° C. while higher yields of hydroxy sulfonate are favored by carrying out the neutralization and hydrolysis at temperatures below 100° C. Suitable hydrolysis temperatures range from about 100°-200° C. The following examples describe the preparation of the precursor olefin sulfonates suitable for preparing hydrogenated olefin sulfonates within the scope of the present invention.
Example 1 -- Preparation of Sodium Olefin Sulfonates
The reactor used for this sulfonation consisted of a continuous falling film-type unit in the form of a vertical water-jacketed tube. Both the olefin and the SO 3 -air mixture were introduced at the top of the reactor and flowed concurrently down the reactor. At the bottom, the sulfonated product was separated from the air stream.
The feed was a straight-chain 1-olefin blend produced by cracking highly paraffinic wax and having the following composition by weight: 1 percent tetradecene, 27 percent pentadecene, 29 percent hexadecene, 28 percent heptadecene, 14 percent octadecene and 1 percent nonadecene. This material was charged to the top of the above-described reactor at a rate of 306 pounds/hour. At the same time 124.2 pounds/hour of SO 3 diluted with air to 3 percent by volume concentration of SO 3 was introduced into the top of the reactor. The reactor was cooled with water to maintain the temperature of the effluent product within the range of 43°-46° C. The average residence time of the reactants in the reactor was less than 2 minutes.
After passing out of the reactor the sulfonated product was mixed with 612 pounds/hour of 11.2 percent aqueous caustic and heated to 145°-150° C. in a tubular reactor at an average residence time of 30 minutes. This step neutralized the sulfonic acids contained in the sulfonation reaction product, hydrolyzed the sultones to hydroxy sulfonic acids and to alkene sulfonic acids and neutralized these sulfonic acids. Olefin sulfonates were produced at the rate of 463 pounds per hour as an aqueous solution having a 45 percent by weight solids content and a pH of 10.8.
A portion of this product was analyzed and shown to be made up of the sodium salts of alkene sulfonic acids, hydroxy alkane sulfonic acids, and disulfonic acids. These three major components were present in a weight ratio of about 50:35:15.
Example 2 -- Preparation of Magnesium C 15 --C 18 α-Olefin Sulfonate
The reactor used for this sulfonation consisted of a small laboratory continuous falling film-type unit similar to the one described in Example 1 above.
The feed was a straight-chain 1-olefin blend produced by cracking highly paraffinic wax and having the following composition by weight: 1 percent tetradecene, 27 percent pentadecene, 29 percent hexadecene, 28 percent heptadecene, 14 percent octadecene and 1 percent nonadecene. This material was charged to the top of the reactor at a rate of 267 grams/hour. At the same time, 112 grams/hour of SO 3 diluted with nitrogen to 2 percent by volume concentration of SO 3 was introduced into the top of the reactor. The reactor was cooled with water to maintain the temperature of the effluent product within the range of 43°-46° C. The average residence time of the reactants in the reactor was less than 2 minutes.
After passing out of the reactor the sulfonated product was mixed with 772 grams/hour of 4.2 percent magnesium oxide slurry and heated to 145°-155° C. in a tubular reactor at an average residence time of 30 minutes. This step neutralized the sulfonic acids contained in the sulfonation reaction product, hydrolyzed the sultones to hydroxy sulfonic acids and neutralized the hydroxy sulfonic acids. The magnesium olefin sulfonate produced still contained trace amount of magnesium oxide which was removed by filtration. The product was brought to about pH 6.5 with H 2 SO 4 and diluted to an aqueous solution having a 28.6 percent by weight solid content.
Example 3 -- Preparation of Hydrogenated Sodium Olefin Sulfonates
The apparatus for this hydrogenation consisted of a 1-liter Magne-Drive autoclave equipped with an accumulator, a constant pressure regulator, and a temperature recording means. The product of Example 1 was diluted with water to a 26 percent solids concentration and was filtered to remove a trace amount of insoluble material. The pH was adjusted to a value of 6.5-7.5 by neutralizing the slight excess of NaOH used in the neutralization and hydrolysis step with H 2 SO 4 . 100 parts of 30 percent hydrogen peroxide was then added to 3,850 parts of the filtered 26 percent solution in an open glass vessel. This mixture was heated to 80° C. and stirred for 1 hour at this temperature, after which time no hydrogen peroxide remained. After cooling this solution to room temperature, 650 g. of it was charged to the previously described autoclave, along with 8.5 g. of Raney nickel. The system was purged with nitrogen and then with hydrogen. It was then pressured with hydrogen to 50 psig. The autoclave was warmed to 100° C. at which temperature hydrogen was again introduced to bring the pressure up to 100 psig. The hydrogen pressure was maintained constant at 100 psig. throughout the run. After 11/2 hours of stirring at this temperature and pressure, and at which time there was no additional hydrogen uptake, the solution was cooled to about 70° C., filtered, and then allowed to cool. After cooling the final product was drum dried.
Example 4 -- Preparation of Hydrogenated Magnesium Olefin Sulfonates
The product of Example 2 was treated with hydrogen peroxide as in Example 3. The residual hydrogen peroxide was decomposed over platinum. The treated product was then hydrogenated with Raney nickel as in Example 3. The final product was drum dried.
The alkene sulfonates need not be completely hydrogenated. Partial hydrogenation of the olefin sulfonate to the extent that at least 50 percent of the alkene sulfonate is converted to alkane sulfonate yields a hydrogenated olefin sulfonate suitable for use in producing high quality non-soap detergent bars. Partial hydrogenation may be accomplished by proceeding as in Example 3, but discontinuing the hydrogenation reaction before hydrogen uptake ceases. Partial hydrogenation can also be carried out by subjecting the olefin sulfonate to hydrogenation after neutralization but prior to hydrolysis.
Example 5 -- Preparation of Bars
The drum-dried magnesium and/or sodium hydrogenated olefin sulfonates, approximately 200 g., were well mixed in the desired ratios. Enough water was gradually added during milling such that the hydrogenated olefin sulfonate could be milled into ribbons of homogeneous composition. It is then formed into bars by molding into a conventional soap bar mold. The bars formed in this way were about 21/8 inches by 13/8 inches by 158 inch in size. These bars were aged by exposure to air in a room at ambient temperature and humidity for one week. The bars then weighed 26-27 g. In general, from about 2 to 15 percent by weight water is sufficient to produce satisfactory bars.
Hydrogenated α-olefin sulfonate bars of varying ratios of sodium and magnesium cations were tested for slough loss and wear rate and the results are summarized in Table I. The slough loss test was run by placing the bar in a 31/2 inch I.D. Petri dish containing 30 ml. of water having 50 ppm hardness. After 18 hours, the bar was removed and any loose gel was rubbed off. Then the bar was allowed to dry for 24 hours and weighed. The loss in weight percent in grams of the bar is reported as slough loss.
An important property of detergent bars is their solution rate under actual washing conditions. A convenient method of measuring the solubility characteristics of a detergent bar is by determining its loss in weight in grams per handwashing. This value is referred to as the bar wear rate. The values are obtained by averaging the weight loss from a number of handwashings by different individuals using tap water at temperatures of about 110° F.
TABLE I
Wear Rate and Slough Loss of Sodium-Magnesium Hydrogenated Olefin Sulfonate Bars
Percent by weight of metal sulfonate Slough loss Wear rate Ex. No. Na Mg Weight % g/washing ____________________________________________________________ ______________ 6 100 0 34 0.80 7 75 25 25 0.77 8 50 50 26 0.63 9 25 75 9 0.33 10 0 100 15 0.56 11 1 100 0 85-100 0.99 ____________________________________________________________ ______________ 1 Unhydrogenated α-olefin sulfonate as active ingredient.
All of the above examples were prepared by formulating a mixture of the correct amount of the sodium hydrogenated olefin sulfonates of Example 3 and the magnesium hydrogenated olefin sulfonates of Example 4.
While completely satisfactory bars can be prepared from hydrogenated olefin sulfonates as shown above, the feel and appearance of the bars may be improved by incorporation of conventional emollients, superfatting agents, opacifiers, fillers, perfumes, dyes, and the like. These additives may constitute up to about 40 percent by weight of the finished bar. Representative conventional additives are the polyethylene glycols, C 12 --C 16 fatty alcohols, stearic acid, mineral oil, fatty acid amides, mixed fatty acid alkanolamine compounds, lauric-isopropanolamide, polyethylene glycol monostearates, and glycerol monostearate.
In addition, it may be desirable to have incorporated within the non-soap synthetic bar other detergent-active materials compatible with the hydrogenated olefin sulfonates in an amount of from 0 to 25 percent by weight of the hydrogenated olefin sulfonates. Such detergent-actives would include straight-chain alkylbenzene sulfonates, straight-chain primary and secondary alkyl sulfates, polyoxyethylene alkylphenol sulfates, acylisothionates, alkyl glyceryl ether sulfonates, and sulfated fatty acid monoglycerides.
DESCRIPTION OF DRAWING
The drawing graphically illustrates the effect disclosed by the data in Table I of the variation of magnesium and sodium salt concentration on the wear rate of the detergent bars. In particular, the graph illustrates the improved characteristics of the detergent bars containing a sodium to magnesium salt concentration ratio of from 2:1 to 1:20, and preferably from 1:2 to 1:9.
As will be evident to those skilled in the art, various modifications of the present products can be made or followed, in the light of the foregoing disclosure and discussion without departing from the spirit or scope of the disclosure or the scope of the following claims.
The present invention is concerned with the field of synthetic non-soap detergent bars and, more particularly, with the preparation of bars or cakes for toilet or bath use from improved mixtures of hydrogenated olefin sulfonates.
Although synthetic detergents have largely replaced soaps for most household laundering and dishwashing uses, they have found little acceptance in the household toilet bar area. Although the detergent literature is replete with examples of synthetic detergent bars and synthetic detergent-soap combination bars, the toilet bar market continues to be dominated by soap bars. The combination bars have had appreciable acceptance but they exhibit the high pH characteristic of soap bars. At the present time, it appears that less than 1 percent of the bar market is satisfied by all synthetic detergent bars.
As disclosed in copending application, U.S. Ser. No. 748,188, filed July 29, 1968, it has been discovered that superior non-soap synthetic detergent bars can be formed employing hydrogenated linear olefin sulfonates as the major active detergent component. In particular, mixtures of straight-chain hydrogenated olefin sulfonates containing from 10 to 24 carbon atoms constitute a superior detergent component for non-soap detergent toilet bars. Although these hydrogenated olefin sulfonate bars comprise a significant advance over the non-soap detergent bars of the prior art, they are not as low in slough loss and wear rate as is desirable.
DESCRIPTION OF THE INVENTION
It has now been discovered that superior non-soap synthetic detergent bars low in slough loss and wear rate can be formed employing improved hydrogenated linear olefin sulfonates as the major active detergent component. In particular, mixtures of sodium and magnesium salts of straight-chain hydrogenated olefin sulfonates containing from 10 to 24 carbon atoms constitute a superior detergent component for non-soap detergent toilet bars. In general, when the ratio of sodium to magnesium salts is in a weight ratio of from 2:1 to 1:20, excellent slough loss and wear rate characteristics are exhibited with little or no appreciable effect on the other outstanding properties of hydrogenated olefin sulfonate detergent bars. Preferably, the ratio of sodium to magnesium salts is from 1:2 to 1:9.
The term "olefin sulfonates" as used in the present invention, defines the complex mixture obtained by the SO 3 sulfonation of straight-chain olefins containing 10 to 24 carbon atoms and subsequent neutralization and hydrolysis of the sulfonation reaction product. This complex mixture contains hydroxyalkane sulfonates and alkene sulfonates, as its major components, and a lesser proportion of disulfonated product.
While the general nature and the major components of the complex mixture is known, the specific identity and the relative proportions of the various hydroxy sulfonate and disulfonate radicals and double bond locations are unknown. Accordingly, a determination of the entire chemical makeup is exceedingly difficult and has not heretofore been successfully accomplished. The mixture is best defined by the process used for producing it.
Optimum detergent bar properties are exhibited by the composition obtained by hydrogenating an olefin sulfonate product which contains from about 25 to 75 percent by weight alkene sulfonates, from about 25 to 65 percent by weight hydroxyalkane sulfonates, and not more than 20 weight percent disulfonates. These optimum compositions are obtained by SO 3 -air sulfonation of C 10 -C 24 straight-chain olefins with SO 3 :air volume ratio of about 1:50-100 and an SO 3 :olefin mole ratio of 1.05-1.25:1, and neutralization and hydrolysis of the sulfonation reaction product at temperatures of 145°-250° C. using one equivalent of base per mole of SO 3 consumed in the sulfonation step.
In addition to the straight-chain α-olefins from wax cracking, suitable olefin starting materials include straight-chain α-olefins produced by Ziegler polymerization of ethylene, or internal straight-chain olefins prepared by catalytic dehydrogenation of normal paraffins or by chlorination-dehydrochlorination of normal paraffins. The olefins may contain from 10 to 24 carbon atoms, usually 13 to 22 carbon atoms, preferably 14 to 20, and more preferably 15 to 18 carbon atoms per molecule. Olefin mixture should have an average molecular weight of at least about 200.
The amount of SO 3 utilized in the sulfonation reaction may be varied but is usually within the range of 0.95 to 1.35 moles of SO 3 per mole of olefin and, preferably, in the range 1.05-1.25:1. Greater formation of disulfonated products is observed at higher SO 3 :olefin ratios. Disulfonation may be reduced by carrying the sulfonation reaction only to partial conversion of the olefin; for example, by using SO 3 :olefin ratios of less than 1 and removing the unreacted olefins by a deoiling process. The unreacted olefins may be removed by extracting the reaction product with a hydrocarbon such as pentane.
In order to obtain a product of good color, the SO 3 employed in the sulfonation reaction is generally mixed with an inert diluent or with a modifying agent. Inert diluents which are satisfactory for this purpose include air, nitrogen, SO 2 , dichloromethane, etc. The volume ratio of SO 3 to diluent is usually within the range of 1:100 to 1:1.
The reaction product from the sulfonation step step may be neutralized with aqueous basic solutions containing the sodium or magnesium hydroxides, carbonates or oxides. In the preferred method, sufficient neutralizing solution may be added to provide for neutralization of the sulfonic acids formed by sultone hydrolysis. Generally, one equivalent of base for each mole of SO 3 consumed in the sulfonation reaction is added to the sulfonation reaction product. The proportion of hydroxyalkane sulfonates to alkene sulfonates in the hydrolyzed neutralized product may be varied somewhat by the manner in which neutralization and hydrolysis are carried out. Thus, reduced amounts of hydroxyalkane sulfonates are obtained by carrying out the neutralization and hydrolysis at temperatures in the range of 145°-200° C. while higher yields of hydroxy sulfonate are favored by carrying out the neutralization and hydrolysis at temperatures below 100° C. Suitable hydrolysis temperatures range from about 100°-200° C. The following examples describe the preparation of the precursor olefin sulfonates suitable for preparing hydrogenated olefin sulfonates within the scope of the present invention.
Example 1 -- Preparation of Sodium Olefin Sulfonates
The reactor used for this sulfonation consisted of a continuous falling film-type unit in the form of a vertical water-jacketed tube. Both the olefin and the SO 3 -air mixture were introduced at the top of the reactor and flowed concurrently down the reactor. At the bottom, the sulfonated product was separated from the air stream.
The feed was a straight-chain 1-olefin blend produced by cracking highly paraffinic wax and having the following composition by weight: 1 percent tetradecene, 27 percent pentadecene, 29 percent hexadecene, 28 percent heptadecene, 14 percent octadecene and 1 percent nonadecene. This material was charged to the top of the above-described reactor at a rate of 306 pounds/hour. At the same time 124.2 pounds/hour of SO 3 diluted with air to 3 percent by volume concentration of SO 3 was introduced into the top of the reactor. The reactor was cooled with water to maintain the temperature of the effluent product within the range of 43°-46° C. The average residence time of the reactants in the reactor was less than 2 minutes.
After passing out of the reactor the sulfonated product was mixed with 612 pounds/hour of 11.2 percent aqueous caustic and heated to 145°-150° C. in a tubular reactor at an average residence time of 30 minutes. This step neutralized the sulfonic acids contained in the sulfonation reaction product, hydrolyzed the sultones to hydroxy sulfonic acids and to alkene sulfonic acids and neutralized these sulfonic acids. Olefin sulfonates were produced at the rate of 463 pounds per hour as an aqueous solution having a 45 percent by weight solids content and a pH of 10.8.
A portion of this product was analyzed and shown to be made up of the sodium salts of alkene sulfonic acids, hydroxy alkane sulfonic acids, and disulfonic acids. These three major components were present in a weight ratio of about 50:35:15.
Example 2 -- Preparation of Magnesium C 15 --C 18 α-Olefin Sulfonate
The reactor used for this sulfonation consisted of a small laboratory continuous falling film-type unit similar to the one described in Example 1 above.
The feed was a straight-chain 1-olefin blend produced by cracking highly paraffinic wax and having the following composition by weight: 1 percent tetradecene, 27 percent pentadecene, 29 percent hexadecene, 28 percent heptadecene, 14 percent octadecene and 1 percent nonadecene. This material was charged to the top of the reactor at a rate of 267 grams/hour. At the same time, 112 grams/hour of SO 3 diluted with nitrogen to 2 percent by volume concentration of SO 3 was introduced into the top of the reactor. The reactor was cooled with water to maintain the temperature of the effluent product within the range of 43°-46° C. The average residence time of the reactants in the reactor was less than 2 minutes.
After passing out of the reactor the sulfonated product was mixed with 772 grams/hour of 4.2 percent magnesium oxide slurry and heated to 145°-155° C. in a tubular reactor at an average residence time of 30 minutes. This step neutralized the sulfonic acids contained in the sulfonation reaction product, hydrolyzed the sultones to hydroxy sulfonic acids and neutralized the hydroxy sulfonic acids. The magnesium olefin sulfonate produced still contained trace amount of magnesium oxide which was removed by filtration. The product was brought to about pH 6.5 with H 2 SO 4 and diluted to an aqueous solution having a 28.6 percent by weight solid content.
Example 3 -- Preparation of Hydrogenated Sodium Olefin Sulfonates
The apparatus for this hydrogenation consisted of a 1-liter Magne-Drive autoclave equipped with an accumulator, a constant pressure regulator, and a temperature recording means. The product of Example 1 was diluted with water to a 26 percent solids concentration and was filtered to remove a trace amount of insoluble material. The pH was adjusted to a value of 6.5-7.5 by neutralizing the slight excess of NaOH used in the neutralization and hydrolysis step with H 2 SO 4 . 100 parts of 30 percent hydrogen peroxide was then added to 3,850 parts of the filtered 26 percent solution in an open glass vessel. This mixture was heated to 80° C. and stirred for 1 hour at this temperature, after which time no hydrogen peroxide remained. After cooling this solution to room temperature, 650 g. of it was charged to the previously described autoclave, along with 8.5 g. of Raney nickel. The system was purged with nitrogen and then with hydrogen. It was then pressured with hydrogen to 50 psig. The autoclave was warmed to 100° C. at which temperature hydrogen was again introduced to bring the pressure up to 100 psig. The hydrogen pressure was maintained constant at 100 psig. throughout the run. After 11/2 hours of stirring at this temperature and pressure, and at which time there was no additional hydrogen uptake, the solution was cooled to about 70° C., filtered, and then allowed to cool. After cooling the final product was drum dried.
Example 4 -- Preparation of Hydrogenated Magnesium Olefin Sulfonates
The product of Example 2 was treated with hydrogen peroxide as in Example 3. The residual hydrogen peroxide was decomposed over platinum. The treated product was then hydrogenated with Raney nickel as in Example 3. The final product was drum dried.
The alkene sulfonates need not be completely hydrogenated. Partial hydrogenation of the olefin sulfonate to the extent that at least 50 percent of the alkene sulfonate is converted to alkane sulfonate yields a hydrogenated olefin sulfonate suitable for use in producing high quality non-soap detergent bars. Partial hydrogenation may be accomplished by proceeding as in Example 3, but discontinuing the hydrogenation reaction before hydrogen uptake ceases. Partial hydrogenation can also be carried out by subjecting the olefin sulfonate to hydrogenation after neutralization but prior to hydrolysis.
Example 5 -- Preparation of Bars
The drum-dried magnesium and/or sodium hydrogenated olefin sulfonates, approximately 200 g., were well mixed in the desired ratios. Enough water was gradually added during milling such that the hydrogenated olefin sulfonate could be milled into ribbons of homogeneous composition. It is then formed into bars by molding into a conventional soap bar mold. The bars formed in this way were about 21/8 inches by 13/8 inches by 158 inch in size. These bars were aged by exposure to air in a room at ambient temperature and humidity for one week. The bars then weighed 26-27 g. In general, from about 2 to 15 percent by weight water is sufficient to produce satisfactory bars.
Hydrogenated α-olefin sulfonate bars of varying ratios of sodium and magnesium cations were tested for slough loss and wear rate and the results are summarized in Table I. The slough loss test was run by placing the bar in a 31/2 inch I.D. Petri dish containing 30 ml. of water having 50 ppm hardness. After 18 hours, the bar was removed and any loose gel was rubbed off. Then the bar was allowed to dry for 24 hours and weighed. The loss in weight percent in grams of the bar is reported as slough loss.
An important property of detergent bars is their solution rate under actual washing conditions. A convenient method of measuring the solubility characteristics of a detergent bar is by determining its loss in weight in grams per handwashing. This value is referred to as the bar wear rate. The values are obtained by averaging the weight loss from a number of handwashings by different individuals using tap water at temperatures of about 110° F.
TABLE I
Wear Rate and Slough Loss of Sodium-Magnesium Hydrogenated Olefin Sulfonate Bars
Percent by weight of metal sulfonate Slough loss Wear rate Ex. No. Na Mg Weight % g/washing ____________________________________________________________ ______________ 6 100 0 34 0.80 7 75 25 25 0.77 8 50 50 26 0.63 9 25 75 9 0.33 10 0 100 15 0.56 11 1 100 0 85-100 0.99 ____________________________________________________________ ______________ 1 Unhydrogenated α-olefin sulfonate as active ingredient.
All of the above examples were prepared by formulating a mixture of the correct amount of the sodium hydrogenated olefin sulfonates of Example 3 and the magnesium hydrogenated olefin sulfonates of Example 4.
While completely satisfactory bars can be prepared from hydrogenated olefin sulfonates as shown above, the feel and appearance of the bars may be improved by incorporation of conventional emollients, superfatting agents, opacifiers, fillers, perfumes, dyes, and the like. These additives may constitute up to about 40 percent by weight of the finished bar. Representative conventional additives are the polyethylene glycols, C 12 --C 16 fatty alcohols, stearic acid, mineral oil, fatty acid amides, mixed fatty acid alkanolamine compounds, lauric-isopropanolamide, polyethylene glycol monostearates, and glycerol monostearate.
In addition, it may be desirable to have incorporated within the non-soap synthetic bar other detergent-active materials compatible with the hydrogenated olefin sulfonates in an amount of from 0 to 25 percent by weight of the hydrogenated olefin sulfonates. Such detergent-actives would include straight-chain alkylbenzene sulfonates, straight-chain primary and secondary alkyl sulfates, polyoxyethylene alkylphenol sulfates, acylisothionates, alkyl glyceryl ether sulfonates, and sulfated fatty acid monoglycerides.
DESCRIPTION OF DRAWING
The drawing graphically illustrates the effect disclosed by the data in Table I of the variation of magnesium and sodium salt concentration on the wear rate of the detergent bars. In particular, the graph illustrates the improved characteristics of the detergent bars containing a sodium to magnesium salt concentration ratio of from 2:1 to 1:20, and preferably from 1:2 to 1:9.
As will be evident to those skilled in the art, various modifications of the present products can be made or followed, in the light of the foregoing disclosure and discussion without departing from the spirit or scope of the disclosure or the scope of the following claims.