US2407647A - Synthetic organic nonsoap detergent in bar form and process of making same - Google Patents

Description

Patented Sept. 17, 1946 UNITED SYNTHETIC ORGANIC NONSOAP DETER- GENT IN BAR. FORM AND PROCESS OF MAKING SAME John W. Bodman, Winchester, Mass., assignor to Lever Brothers Company, Cambridge, Mass., a

corporation of Maine No Drawing. Application August 14, 1940, Serial No. 352,519

8 Claims. 1

This application is a continuation-in-part of application Ser. No. 85,985, filed June 18, 1936, which matured as Patent No. 2,215,539 on September 24, 1940. Application Ser. No. 85,985 is a continuation of application Ser. No. 665,063, filed April 8, 1933.

The present invention relates to an improvement in the manufacture of detergents and relates more particularly to the preparation of the so-called non-soap detergents" in commercially desirable forms.

The term non-soap detergents is used herein to designate materials having a cleaning action which are derivatives of higher fatty compounds or compositions other than the usual soaps, i. e., soluble metal salts of fatty acids. For convenience, I prefer to utilize the, type of non-soap detergents which are readily available in their relatively pur form and which under normal conditions of temperature and pressure are nonliquid. Of these may be mentioned the Gardinols which are salts of the sulfated higher fatty alcohols, the Emco preparations which may be described as sulfocarboxylic acid esters of alcohol amine derivatives, and the A-typ of the Igepon class of products which are fatty acid esters of hydroxyethane sulfonic acid. All such compositions are well known in the art and may be defined generically as synthetic non-soap organic compounds having surface active properties.

In accordance with my invention, non-soap detergent compounds may be prepared in a coherent and coalescent bar or cake form which has the fine texture, firmness, shape stability and wearing qualities desirable in high grade toilet soaps. Moreover, the product may be characterized by a desirable mildness while possessing the bulk and degree of solubility preferred in detergent bars or cakes.

Non-soap detergents as a class of compounds are relatively expensive and highly soluble -in comparison with the usual soluble soaps which they are intended to replace for cleansing and other purposes. In marketing these compounds heretofore, it has been considered necessary to prepare a product which has the bulk of an equally effective soap product and at the same time will not be materially higher in cost. To accomplish this result, it has been customary to add diluents generally of an inactive character, for example, of the type of sodium sulfate or sodium chloride. Also those which have at least some of the properties of a soap builder may be added. The presence of material proportions of inorganic electrolytes may impart to the deter- 2 gent a harsh action when applied to the skin, which, obviously is undesirable in. high grade toilet preparations.

It is now possible in accordance with my invention to prepare non-soap detergents in bar form which can be used economically as Waste or disintegration of the bar on use is minimized. If desired, the usual diluents or fillers may be omitted entirely without a sacrifice of bulk and wearing qualities.

The diluents commonly used have no marked cohesive properties and when used in any material proportlons render the detergent noncohesive and dificult of successful preparation in bar form. Attempts have been made to neutralize at least in part this lack of cohesiveness by the use of binding agents. The addition of such addition agents for the purpose of binding together the adulterated detergent particles into bar form. however, is generally undesirable. Among the other disadvantages, for example, of such a bar or cake, is that it will not dissolve into a clear solution. Moreover, the bar or cake is not coherent and coalescent, being made up of individual distinct particles, and does not possess the firmness, fine texture, and appearance desired in toilet preparations. My invention may be utilized to produce a coherent and coalescent bar or cake of non-soap detergent without the use of any binding agents whatsoever.

The products of my invention may be made entirely from non-soap detergents and with or without small amounts of diluent. If it is desired, varying. amounts of soap may be incorporated therewith. In fact, it is found to be advantageous in many cases to combine the desirable properties of non-soap and soap detergents. While liquid or semi-fluid non-soap deterg nts generally may not be prepared in bar or cake form, I have found that in accordance with my invention they may be so modified that they may be eflectively used in the bar form when suitably blended with other detergents having a normally solid form, such as a hard soap or other non-soap detergent.

In accordance with my invention the non-soap detergents may in one preferred form be aerated, i. e., may have small amounts of a compatible gas distributed throughout the detergent mass. If desired, the detergent may be sufiiciently aerated to reduce its specific gravity below that of water, thereby producing a floating product.

The formation of the improved products of my invention may be carried out by working the materials in admixture with small amounts of water, preferably in a closed container, at temperatures suificient to render the mass plastic or semi-fluid to fiuid. Under these conditions, it is possible to manufacture a coherent bar of nonsoap detergent which may be aerated or nonaerated, floating or non-floating depending upon the conditions of processing; and one having in the preferred embodiment a characteristically reduced solubility and tendency to disintegrate; and also one having the properties of fine texture, continuity and appearance as well as other desirable characteristics important to the production of a commercially acceptable product in cake orbar form.

In producing the the new non-soap detergent bar or cake, a non-soap detergent stock, preferably in relatively pure form and solidified in the form of pellets, particles or fragments, is reduced to a heated plastic or semi-fluid condition while it is intensely agitated or worked in a chamber closed to the atmosphere. The particular kind of mechanical agitation to which the non-soap detergent mass is subjected for preferred results should be sufiicient to move all portions of the soap mass relatively to each other and expose them equally to any source of heat which may be utilized. The operation may be discontinued when there results a unitary mass of non-soap detergent suitable for passing into form-imparting means where it may be cooled and solidified while retaining its continuous structure. If an aerated mass is to be produced, a compatible gas, such as air, may be introduced into the mass while in a plastic, semi-fluid to fluid state and thoroughly distributed through the mass during the Working operation.

The process may be carried out in a batch type of operation or may be practiced in a continuous manner, if desired. It is possible to use a machine of the Banbury mixer type as disclosed in the patent to Banbury, No. 1,200,070, issued October 3, 1916. A more desirable type of apparatus for continuous operations would be the apparatus described in the patent to Pease, No. 2,048,236, issued July 21, 1936. The apparatus which is selected should be adapted to thoroughly mix, shear or knead the non-soap detergent stock under desired conditions of temperature, moisture content, and pressure.

The temperature range under which I prefer to carry out my invention will depend primarily upon the type of non-soap detergent selected. The temperature should be sufficient to render the detergent plastic or semi-fluid to fluid and capable of being readily worked into a coherentcoalescent body of a continuous structure in the types of apparatus described above. For most commercially available non-soap detergents, a temperature range of from 100 to 200 F. will be satisfactory. Temperatures above 200 F. may be used but possibly without achieving the full benefits of my invention in its preferred form, for with some non-soap detergents it has been found that when excessively high temperatures are used, the resulting detergent product will be subjected to generally undesirable shrinkage in bar form during cooling, although in other respects the results may be satisfactory. Temperatures below 100 F. may be utilized with some non-soap detergents, provided the desired degree of plasticity is obtained. In using liquid or semiliquid non-soap detergents with solid detergents the temperatures used should be sufficient to make plastic or otherwise modify the solid detergent to the most desirable form. The temperature should permit uniform blending and a continuity of the mass in the final product.

The method utilized for obtaining the desired temperature conditions is not critical. For convenience, the non-soap detergent stock, for example, in particle form, may be preheated in part or in whole to the desired temperature prior to charging it into the mixing apparatus, or heat may be applied to the detergent while it is in the mixer, either during or before agitation, in any convenient manner.

The processing of the non-soap detergents may be carried out at a moisture content varying over a wide range and depending primarily upon the type of non-soap detergent selected for processing. In most cases, a moisture content of from 10-20% will be satisfactory. A moisture content of less than 10% may be utilized with most nonsoap detergents, if desired, but in general lower percentages of moisture render the material difiicult to plasticize, at least in the types 01' apparatus which are available at present. When a moisture content of approximately 20% is exceeded, the product in most cases tends to have a rather soft and sticky form. The upper moisture limit, however, will vary considerably, depending upon the type of non-soap detergent selected. For example, it has been found that the Emco products referred to hereinbefore may be formed into a firm bar with a moisture content as high as 35% if used alone. If blended with other detergents that would be made undesirably liquid or sticky by high proportions of water or high temperatures, a lower average water content would be more suitable.

For convenience, I prefer to utilize as a starting material those non-soap detergents prepared commercially with a moisture content within the limits set forth above; if necessary, however, the moisture content may be regulated prior or during processing in any suitable manner known to the art.

With a view to obtaining preferred characteristics in the product, it is desirable to subject the non-soap detergent mass to pressure while working. This insures an effective working action and minimizes the escape of moisture and air from the mass. It is desirable to have the air distributed in a fine uniform condition and it is believed that the use of pressure increases the desirable air distribution. The pressure may cause the air to be dissolved in the plastic or semi-fluid mass. The air is then released in a highly dispersed form throughout the mass upon release of pressure upon the mass. Any convenient pressure beginning at slightly over atmospheric to pounds per square inch or more may be used. Pressures of 25 pounds per square inch have been found suitable. The pressure is preferably increased when higher temperatures are employed.

In carrying out my invention, it is desirable to use non-soap detergents which are available commercially in a relatively pure state or which may be readily purified. In addition to having a milder action on the skin, it has been found that the absence of inorganic salts increases the firmness and fine texture of the resulting product. However, small percentages of inorganic material, for example, up to 15%, may be present in the detergent product without undesirable effects.

If desired, varying percentages of ordinary soaps may be incorporated with the non-soap detergents. These materials may be mixed in all Proportions and for many purposes as high as 7 to 80% of soap may be used. When material percentages of soap are incorporated it generally is desirable to modify and blend the non-soap detergent with the soap by working as described, utilizing preferably temperatures of more than 145 F. and with a moisture content of the soap of less than 25%. I have found that by blending as described a non-soap and soap detergent a product may be produced having particularly desirable properties. The detergent effectiveness is materially increased in hard water districts and in sea water and any tendency for the more soluble non-soap detergent incorporated to leach out or separate is minimized in view of my processing. In its preferred form this product is aerated during processing, sufficiently to float.

For convenience, the non-soap detergent stock to be used in carrying out my invention may be in the form of the usual commercial spray-dried product. When the operation is carried out in a continuous fashion the charging of the spraydried non-soap detergent into the apparatus is usually accompanied by the inclusion of sumcient air to insure an aerated or even a floating product. If a compacted charge is used, it may be necessary to supply an additional quantity of air to the apparatus. When operating under a batch system, sufficient air may be made available for incorporation by only partly filling the machine.

Agitation of the non-soap mass preferably with heating and under pressure may be continued for a sufficient period of time to disseminate the air in a finely-divided condition throughout the entire mass and to plasticize the mass as a continuous and coherent body. When the mass is completely mixed, it may be released or discharged by extrusion under pressure or otherwise into a mold or form-imparting means. If desired the pressure may not be released until in the form-imparting means. The detergent cools and solidifies in a desired coherent and coalescent form and may be reduced to any desired shape by cutting or trimming and impressed with a design by a stamp or die.

The following examples serve to illustrate the manufacture of a satisfactory coherent floating bar from non-soap detergents.

Example I Per cent Sodium salt of lauryl sulfate 81 Inactive diluent 9 Water 10 This mixture was Worked vigorously at a temperature of 200 F. and then extruded into a mold and cooled. The resulting bar had a specific gravity of 0.88.

Example II Per cent Non-soap detergent (sulfocarboxylic acid ester of alcoholamine derivative) 59.5 Potassium chloride 7 Potassium sulfate 3.5 Water 30 The non-soap detergent was composed of sulfocarboxylic acid esters of mono-ethanolamine. This mixture was Worked at a temperature of 160 F. The resulting bar had a specific gravity of 0.83.

Example III Per cent Non-soap detergent (sulfocarboxylic acid ester of alcoholamine derivative) 8.5 Potassium chloride 1 Potassium sulfate Soap (20 coconut oil, tallow) anhydrous Water The non-soap detergent utilized in the above example was composed of sulfocarboxylic acid esters of mono-ethanolamine. When processed at a temperature of F., this mixture produced a floating bar of good'texture.

Soap (20 coconut oil, 80 tallow) anhydrous 77 Water 18 The non-soap detergent used in this example was an alkyl aryl sulfonate. When processed at a temperature of 200 F., this mixture produced a floating bar.

In accordance with the disclosure herein it will be seen that a bar or cake may be prepared in accordance with my invention which will wear sufficiently slowly to make its use economical when compared to detergent products made from ordinary soaps or from non-soaps with high proportions of fillers. The bar has the texture and appearance desirable in a high grade toilet soap and is satisfactory in every respect for ordinary usage. In addition it may be aerated sufficiently to float thus having, in addition to the advantages of a fine toilet soap, the well known desirable properties of a floating soap.

It is to be observed that the amount of inert material present in an example of a preferred product is a relatively small amount, for example, less than 15%. Despite the presence of only a small amount of inert filler or its complete absence the non-soap detergent product in bar form is not wastefully given off during ordinary usage. Because of this increased coherency of the mass as a result of the utilization of my process it is possible to make a coalescent bar consisting entirely or in part of non-soap detergent material without the disadvantage of using binders.

Apparently the processing as described tends V to decrease the solubility or disintegration of the mass sufficiently to release upon use, and without waste, only about that amount of deter-gent desired or necessary for a detergent effect. A preferred bar or cake results having a continuous body free from laminations or cleavage planes.

The aeration of the mass is also an important factor in the production of a preferred form of non-soap detergent bar for by aeration the bulk of the relatively expensive ingredient is materially increased and its solubility decreased. The type of aeration is probably an important factor in obtaining these results in a maximum amount. The best embodiment, I have found, results from aerating the mass while working in a plastic or semi-liquid heated condition under pressure. The product so formed is characterized by an extremely fine air distribution imparting a white color and smooth feel. A material proportion of the air cells in some masses so processed have been found to be highly irregular in shape and constitute no more than tiny fissures between crystals.

It will be apparent that my invention is susceptible to many variations and all uch varia- 7 tions are intended to be included in the scope of the following claims.

I claim:

1. A process for making a coherent and coalescent bar of a normally non-liquid synthetic organic non-soap detergent compound having surface active properties, said bar having an aerated continuous mass of fine texture and firmness comprising subjecting a mass of a normally nonliquid synthetic organic non-soap detergent compound having surface active properties having a moisture content of less than about 35% to a U temperature of the order of 100 to 200 F., working the mass in the presence of a compatible gas under pressure, and thereafter forming the mass into bars or cakes.

2. A process for making a coherent and coalescent bar of a normally non-liquid synthetic organic non-soap detergent compound having surface active properties, said bar having an aerated continuous mass of fine texture and firmness comprising subjecting a mass of a normally non-liquid synthetic organic non-soap detergent compound having surface active properties having a moisture content of leSs than about 35% to a temperature at which the mass is semi-fluid to fluid and continuous, aerating the continuous mass under pressure while working, and thereafter forming the mass into bars or cakes.

3. A process for making a coherent and coalescent bar of a normally non-liquid synthetic organic non-soap detergent compound having surface active properties, said bar having good wearing qualities and containing less than of diluent material, which comprises subjecting a mass of a normally non-liquid synthetic organic non-soap detergentcompound of at least 85% purity having surface active properties, to a temperature at which the mass is semi-fluid to fluid and continuous, aerating the continuous mass under pressure while working and thereafter forming the mass into bars or cakes.

4. A process for making a coherent and coalescent bar of a synthetic organic non-soap detergent compound having surface active properties and an alkali metal soap, said bar having an aerated continuous mass of fine texture and firmness which comprises subjecting a mass comprising more than about 4% of said non-soap detergent compound and not more than 80% of said alkali metal soap to a temperature at which the said mass is semi-fluid to fluid and continuous, aerating with working said semifluid to fluid and continuous mass in the presence of a compatible gas under pressure and solidifying and forming the said aerated mass into bars or cakes.

5. The process of producing a floating bar from a mass of a major proportion of alkali metal soap and a minor proportion of a synthetic organic non-soap detergent compound having surface active properties, said bar having fine texture, firmness and a continuous aerated mass, said process comprising subjecting said mass in a closed chamber under pressure to intensive agitation while at a temperature whereby the mass is in a plastic or semi-fluid condition and in the presence of air and forming the continuous aerated mass into a firm bar having a fine texture and a continuous aerated mass.

6. An aerated cake or bar suitable for detergent purposes comprising a normally non-liquid synthetic organic non-soap detergent compound having surface active properties having a continuous aerated mass of fine texture and firmnes-s, said aerated mass resulting from the cooling of a semi-fluid to fluid and continuous normally non-liquid synthetic organic non-soap detergent mass through which a compatible gas has been disseminated while Working under pressure and at a temperature suflicient to render said non-soap mass at least semi-fluid and continuous.

7. A process for making a coherent and coalescent bar of a synthetic organic non-soap detergent compound having surface active properties and an alkali metal soap, said bar having an aerated continuous mass of fine texture and firmness which comprises subjecting a mass comprising not morethan of soap with a moisture content of less than 25% and more than about 4% of said non-soap detergent to a temperature of more than F., aerating while working the mass under pressure in the presence of a compatible gas and forming the said aerated mass in bars or cakes.

8. A floating aerated cake or bar suitable for detergent purposes comprising a synthetic organic non-soap detergent compound having surface active properties in an amount of more than about 4% and an alkali metal soap in an amount of not more than about 80%, said cake or bar having a continuous and uniformly aerated mass, said aerated mass resultingfrom the cooling of a semi-fluid to fluid and continuous synthetic organic non-soap detergent compound having surface active properties in an amount of more than about 4% and an alkali metal soap in an amount of not more than about 80%, through which a compatible gas has been disseminated while working under pressure and at a temperature sufiicient to render said non-soap mass at least semi-fluid and continuous.

JOHN W. BODMAN.