US 2678921 A
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Patented May 18, 1954 UNITED STATES PATENT OFFICE PROCESS 0F PRODUCING A MILLED NON- SOAP DETERGENT IN BAR, FORM No Drawing. Application August 4, 1948, Serial No. 42,537
6 Claims. 1
This invention relates to improvements in synthetic detergents, and more particularly to an improved method of treating detergent masses comprising solid, synthetic organic detergent material to produce a compacted mass or body which is cohesive and firm, and which can be readily formed into a commercially desirable bar or cake.
The advent of synthetic, so-called non-soap Organic detergents, has brought about a demand for such products in the form of bars, cakes or tablets. However, attempts so far to make them in bar form using conventional soap making equipment and processes have raised new problems in the milling and plodding steps of their manufacture. Inasmuch as plodding is an es sential step in the making of toilet soap in commercial quantities, it is also, so far as now known, essential to the making of synthetic detergents in bars in commercial quantities.
Prior to this invention, however, it has been very diiiicult to produce plodded bars and cakes of these synthetic detergents commercially without the addition of various fillers, diluents and the like, in such amounts that the detergent efficiency of the surface-active constituent is greatly lowered. Moreover, attempts to make synthetic bars using ordinary soap making methods and machinery have been largely unsuccessful because of difliculties encountered in plodding the detergent mass to produce a product which can be readily extruded, pressed and cut into bars and cakes.
The difliculties appear to be due partly to the fact that such synthetic detergents, in general, possess a higher wetting power and are more sensitive to changes in working temperatures than ordinary soaps, requiring in most cases that a fixed temperature be maintained during plodding. Also, the synthetic detergent particles do not cohere readily, even in the presence of a small amount of water, so that, without the use of an added binder, it has been practically impossible to produce a firm, coalescent bar. Otherwise attempted plodding has had essentially the same result as plodding crystalline salts such as sodium chloride, or like substances.
Striving to overcome this lack of cohesiveness, additions of china clay and the like inert materials have been made to some advantage, but the relatively large amounts necessary lowered the efficiency of the detergent when in cake form.
Use of a certain amount of water in the production of milled synthetic bars or cakes also has been believed necessary heretofore in order to produce a sufiiciently pasty mass for plodding. In fact, prior to this invention, it has been the general practice to provide the detergent body which was to be milled or plodded with a moisture content of from about 10 to 20%, and even a higher moisture content has been recommended. Lower percentages of moisture content than about 5% were believed to be undesirable, because there has been indications that as the moisture content is lowered it becomes increasingly more difficult to mill and especially to plod such a detergent mass.
It has now been discovered, however, that the difiioulties encountered in plodding these solid, synthetic detergent masses to produce a compacted detergent body suitable for forming into cars and cakes may be substantially overcome, or greatly lessened, by employing low moisture content material which is plasticized by the addition of high-boiling organic plasticizers of limited solubility in water which broaden the plastic range, and by carrying out the plodding operation while the detergent mass is heated within this broadened temperature range wherein the same remains plastic and workable.
The invention in its broadest aspect comprises the improvement in the process or plodding a detergent composition comprising essentially solid, synthetic, organic non-soap detergent material which comprises heating and plodding the synthetic detergent mass while the same is of low or reduced moisture content, and contains sufficient amount of a high molecular weight organic compound or mixture of organic compounds which function both as a plasticizer and a plasticity modifier so that the plasticity range or temperature at which the detergent mass may be plodded is considerably wider than otherwise would be the case.
Suitable amounts of other substances, such as fillers, builders, coloring material, perfume, etc. also may be incorporated to produce a finished product having the physical characteristics desired. The temperature to which the detergent mass is subjected during plodding will depend largely upon the particular synthetic material used as well as the plasticizer employed, but is sufiicient to maintain the mass soft and workable but not so high as to convert the same into a liquid state.
In accordance with this invention the moisture content of the detergent mass is reduced to a low percentage amount, or such that it does not contain more than about 5% by weight and preferably is below 2%, A suitable amount of a nonvolatile high molecular weight organic plasticity modifying agent is incorporated, and the mass is heated to a plastic state and plodded while thus heated. By employing such a method it has been found that the detergent mass can be readily plodded into a cohesive, homogeneous, uniform body which can be extruded in the form of a bar, and which in turn, may be cut into blanks and pressed into firm, smooth cakes.
Several important advantages are obtained by utilizing the present invention of producing synthetic detergent bars and cakes. For instance, by reducing the moisture of the detergent mass rather than by incorporating water or watercontaining ingredients, and by incorporating an organic plasticizer which widens the plasticity range and dissolves but slowly in water, and plodding the mass while heated, the degree of softening can be controlled and a firm, non-sticky bar produced. Moreover, by lowering the moisture content of the detergent mass such that further drying out of the same becomes negligible, the problems encountered due to substantial changes in the moisture content, as may result due to evaporation, are avoided.
It has been observed that the working temperature for plodding solid synthetic non-soap detergent m a s s e s, containing appreciable amounts of water, generally lies within a critical range of a few degrees, and, unless strict control is exercised, sticking and damage to the equipment and/ or synthetic product during plodding may result. In some cases, Where the mass is. allowed to vary a few degrees from this critical temperature during plodding, the detergent mass sets either too rapidly or too slowly, so that the batch can not be used. Moreover, unless such a batch is reworked immediately, it may have to be discarded inasmuch as upon aging it tends totake on a permanent hardening eliect or otherwise change physically, so that it can not be properly disseminated and evenly distributed. through a subsequent detergent mass.
The ease by which scrap can be reworked is one of the important advantages of the present process. In this regard, it has been observed that the detergent body after plodding can be stored and later reworked without it having changed its composition or physical state to such extent that the mass can not be properly reworked into a. subsequent detergent mass. Thus, significant advantages are gained from a manufacturing standpoint through the elimination of scrap, the reduction in labor and handling cost, and the decrease in floor space requirement.
Various solid non-soap synthetic detergents may be used in making the plodded detergent body in accordance with this invention. For example, the non-soap synthetic detergent material may include the solid, water-soluble salts of one or more sulfated or sulfonated organic compounds, the alkyl radical groups of which contain at least eight carbon atoms, such. as higher fatty alcohol sulfates (Gardinols), sulfated or sulfonated monoglycerides i. e. sodium glyceryl monolaurate sulfate (Syntex M), secondary alcohol sulfonates i. e. dioctyl sodium sulfosuccinate (Aerosol O. '13.), alkyl aryl sulfonates i. e. sulfonated benzene which contains an alkyl substituent of about to 14 carbon atoms (Oronite, Santomerse, Ultrawet, Kreelons, Nytron, etc), alkyl sulfonates i. e. sodium alkyl sulfonates produced from petroleum or similar hydrocarbons (Mersolates, Merpols, etc.), fatty acid esters of alkyl hydroxy or amine sulfonic acid i. e. sodium B-oleylethanesulfonate (Igepon A) and sodium ,8 amine ethanesulfonate (Igepcn T), and other water-soluble salts of other sulfuric reaction products of high molecular weight organic compounds which are characterized by their high solubility in water and superior detergent properties. Nonionic, solid synthetic detergents may be used, i. e. polymerized ethylene oxide condensates, fatty acid polyoxyethylene derivatives, etc., and marketed under such names as Biopal, Sorapal, Igepal, etc. Also mixtures of the nonionic type detergents with ionic detergents may be utilized.
Substances employed as plasticizing agents are organic compounds which are solids, semi-solids or oily liquids at ordinary temperatures and of the high boiling non-volatile type havin limited solubility in water, or at least dissolve very slowly therein. They are also resistant to crystallization and segregation under the diiferent temperature and aging conditions to which the detergent bar or cake may be subjec' ed during storage and use. The plasticizing substances which are solid or semisolid, and which maintain a more or less definite form at ordinary temperatures, are hereinafter referred to as normally solid substances.
Organic compounds which have been found to function satisfactorily as plasticizing agents which broaden the plasticity range, as aforementioned, are the high molecular weight fatty acid esters of polyhydrlc alcohols. For example, long-chain polyhydric alcohol mono and distearates and particularly the ether-alcohol fatty acid esters, i. e. diethylene glycol mono and distearates, being especially useful. lhese compounds also function as emulsifying agents, thus promoting the formation of a synthetic detergent bar having a smooth, uniform texture throughout. Other organic plasticizing agents which may be used are the normally solid polyethylene glycols (a known product being sold under the name Carbowax), glycerol mono esters of coconut fatty acids, ethylene glycol distearate, and the diethylene glycol mono and di-esters of palmitic, myristic, oleic, lauric and coconut oil acids; propylene glycol mono and di-esters of stearic, oleic, lauric, myristic, palmitic, coconut oil fatty acids, etc., as well as suitable glyceryl and ethylene glycol mono esters of such fatty acids, and the like, which esters are normally solid, or Olly liquids, and which dissolve in water but at a slow rate. Mixtures of the various organic compounds may, of course, be employed. Where, however, substances are used which are readily dissolved in water there is a tendency towards the production of a bar which is not as firm and dry to the touch as otherwise, and the finished bar or cake dissolves less slowly in water. A plodded detergent bar, which contains plasticity modifying agent as herein described, hardens gradually upon standing in the air at room temperatures without changing its other physical properties or its chemical properties.
. The required proportion of plasticizer varies depending upon the composition to be plodded and the plasticizing agent employed. Additions of relatively small amounts up to 20% or more by weight of the detergent mass may be utilized to advantage.
The moisture content of the synthetic detergent mixture plcdded is preferably reduced as much as practicable, as by initially spray drying or roll drying the mass prior to plodding so that most or practically all the water is removed.
This facilitates the plodding operation. When, however, the moisture content of the mass is substantially above 5% by weight it is difficult to plod satisfactorily, the mass tending to become very soft approaching a liquid state. Moreover, as the water content is further increased, the extruded bar and cakes made therefrom become increasingly softer, presenting relatively sticky surfaces which is undesirable. Aside from these disadvantages, finished bars or cakes made from the higher moisture content material. dissolve inv water at a much faster rate than desired, and they do not dry to a hard firm cake after each use.
The lower water content of the synthetic detergent mass from which the bars and cakes are produced in accordance with this invention, has the further advantage of permitting the exercise of some control over the speed at which the synthetic cake dissolves in water. For example, by varying the proportion of the constituents while maintaining the synthetic detergent mass substantially anhydrous, the water dissolving properties of the finished bar or cake may be varied, and bars made which dissolve in water at a slower and more satisfactory rate.
By thus providing a synthetic detergent mass which is of relatively low moisture content, and which contains a plasticizing agent whereby the mass tends to remain plastic and workable over a fairly wide temperature range, for example 110 to 170 F., the plodding operation can be more easily and effectively carried out.
Where relatively high temperatures are employed in plodding operations, for example in the neighborhood of 200 F. or above, as may be required without a plasticizing agent, there is always the danger of producing discolorations in the finished bar or cake, or even destruction of the detergent itself, due to this high temperature treatment. This, of course, is undesirable and has been overcome in the novel process of this invention by substantially lowering the moisture content of the synthetic detergent mass, and incorporating organic plasticizers whereby the detergent mass can be plodded while heated to a lower temperature than otherwise may be required.
Utilizing a plasticized mass, as described hav ing a low moisture content, the plodding may be accomplished while the mass is heated to around 115 F., or lower, although for most purposes the plodding is carried out between about 120 and 150 F. By plodding the detergent mass at this relatively low temperature and low moisture content, it is not necessary to add preservatives as has been generally necessitated with certain higher moisture detergent masses when attempting to plod the same.
Any waste or scrap detergent formed may be reworked even after aging several days or a month without producing an inferior detergent bar. Likewise, where the plodder is stopped during operation, it is unnecessary to remove the synthetic detergent material, or disassemble and clean the plodder prior to resuming plodding, as has been often required heretofore, particularly where attempts have been made to plod a synthetic detergent body which contained substantial amounts of water.
The following specific examples are given merely to illustrate how the invention may be practiced, the percentage amounts referred to throughout the description being by weight.
Example I Percent by weight Sodium salt of the sulfated monoglycerides of coconut oil fatty acids (salt-free) 78.0 Zinc stearate l 15.0 Diethylene glycol monostearate 6.0 Titanium dioxide 0.5 Perfume 0.5
The synthetic detergent and the remaining in gredients, except the perfume, were suitably admixed and the mass passed through a three-roll mill several times, the perfume being incorporated near the end of the milling operation to prevent its loss by evaporation. The warm ribbone from the mill, which contained approximately one-half percent by weight moisture, were then transferred to a plodder and plodded while heated to a temperature between 130 and ll0 F. The barrel of the plodder was preheated Example If Percent by weight Sodium salt of the sulfated monoglycerides of coconut oil fatty acids salt-free) 67.5
Aluminum palmitate 15.0 Diethylene glycol distearate 15.0 Titanium dioxide 1.0 Perfume 1.5
The above mixture, comprising the synthetic detergent, filler, and plasticizer was roll dried to provide a low moisture mass, and the detergent mixture was then passed, through a three-r011 mill several times during the latter part of which operation the perfume was incorporated. Thereafter the warm ribbons formed on the roll, and containing approximately one percent moisture, were transferred to a plodder and plodded at a temperature of between to F. In this instance, the plodding was carried out under a vacuum, such as described in the United States patent to Schwa-ntes 2,146,770, to produce a higher specific gravity non-floating bar. After plodding, the mass was extruded in the form of a bar which was cut into cakes or blanks and pressed in a die to provide a finished cake of the desired shape and markings. The extrusion nozzle of the plodder was heated somewhat above the plodding temperature, as in Example I, to produce an extruded bar having a smooth, even surface.
Example III and di-stearates of diethylene glycol) 8.0 Titanium dioxide 0.5 Perfume 0.5
The spray dried solid synthetic detergent and remaining ingredients were suitably admixed and aeaaoer milled as described in Example I. The warm ribbons from the mill, and which contained approximately one and one-half percent moisture, were then transferred to a preheated plodder and vacuum plodded as described in Example II. A smooth plodded bar was obtained which was cut into blanks to form cakes.
Example IV Percent by weight Sodium salt of the sulfated monoglycerides of coconut oil fatty acids (salt-free) 48.0 Igepon T (sodium fl-oleyl-amino-ethanesulfonate) 2.0 Boric acid 23.0 Disodium diacid pyrophosphate 10.0
Carbowax 4000 (solid polyethylene glycols) 10.0
Glycerine 1.0 Sodium soap chips 2.0 Irish moss 2.0 Titanium dioxide 1.0 Perfume 1.0
The above mixture of constituents, except the perfume, were suitably mixed and roll dried with lbs. of steam to produce a low moisture mass.
Example V Percent by weight Sodium salt of the sulfated monoglycerides of coconut oil fatty acids (35% active synthetic) 88.75 Diethylene glycol monostearate 10.00 Coloring material 0.25 Perfume 1.00
The constituents were admixed similarly as in Example I to provide a low moisture mass which was plodded while heated to between 115 and 125 F.
Example VI Percent by weight Oronite (sodium salt of alkyl aryl sulfonate active synthetic) 87.00
Diethylene glycol monostearate 4.00 Zinc stearate 7.00 Titanium dioxide 1.00 Perfume 1.00
The above ingredients were roll dried as in Example IV to produce a low moisture mass which was plodded while heated to between 120 and 130 F.
Example VII Percent by weight Spray-dried Igepon AP (sodium salt of 13- laurylethanesulfonate active synthetic) 80.00 Magnesium stearate 12.00 Diethylene glycol monostearate 6.00 Titanium dioxide 1.00 Perfume 1.00
The constituents were suitably mixed as described in Example I to provide a detergent mass having a low moisture content. The mass was then plodded while heated to between and Example VIII Percent by weight Spray-dried sodium salt of the sulfated monoglycerides of a mixture containing 65% hydrogenated tallow and 35% hydrogenated coconut oil 10% active synthetic) 82.0 Zinc stearate 12.0 Diethylene glycol monostearate 5.0 Titanium dioxide 0.5 Perfume 0.5
The ingredients were admixed as described in Example III to provide a low moisture detergent mass which was heated to a temperature between 130 and F. and plodded.
Example VIII illustrates the use of sulfated hydrogenated tallow and coconut oil in place of coconut oil fatty acids, or the like fatty oil acids. Mixtures of hydrogenated tallow with fatty oil acids i. e. stearic, palmitic, etc., may also be utilized. Further, by varying the percentage amounts of hydrogenated tallow used, a bar having higher or lower solubility may be produced. In general, with the use of higher amounts of hydrogenated tallow there is produced correspondingly lower solubility bars, but with increased amounts the sudsing and lathering properties of the bars are lessened which for some purposes are undesirable.
Instead of employing the relatively pure salt of the sulfated or sulfonated monoglycerides of coconut oil fatty acids, the synthetic detergent may contain relatively large or small amounts of sodium sulfate or such other salts as may be formed during neutralization of the sulfated or sulfonated substances. Furthermore, the addition agents, i. e. fillers, builders, coloring matter, etc., may be omitted altogether, if desired, or added in substantially reduced amounts such as illustrated in Examples V and VI.
The proportionate amounts of the components used in making the plodded detergent mass are not critical and may be widely varied and substitutions made depending upon the properties wanted in the final product. Likewise the synthetic detergent may comprise relatively large or small amounts of salts or modifying agents, such as may be formed during production of the synthetic detergent salt, as aforementioned, or as subsequently incorporated.
The addition of inorganic builders, such as phosphates, carbonates, bcrax, etc., and/or organic builders, i. e. carboxymethylcellulose, higher fatty acid alkylolamides, and etc., may be made to obtain certain desired detersive characteristics. Inorganic or organic coloring materials, 1. e. pigments, dyes etc., may be utilized to give the plodded detergent mass or bar a pleasing color or tint. Some coloring materials, such as titanium dioxide, function both as a color embodying agent and a hardener.
Glycerine may be incorporated, as is illustrated in Example IV, to impart emollient characteristics to the finished bars or cakes, and to enhance their gloss. Olive oil also may be used for this purpose, and if desired germicidal substances may be added which are compatible and stable.
Although the sodium salts of the different sulfated or sulphonated synthetic detergents are generally preferred, other salts may be used, and may be more advantageously employed in certain instances. For example, the corresponding salts of calcium, barium or magnesium, or mixtures thereof may be utilized.
Various methods may be employed to heat the plodder, such as by the use of fluid heated jackets, electrical resistances or the like, the plodder being heated sufliciently to cause the detergent mass to become plastic and workable, but not so high as would transform the mass into a liquid state or melt. The nozzle of the plodder is heated so that its temperature is somewhat above that of plodding in order to produce an ironing effect on the detergent mass as it is extruded, smoothing out any slight imperfections at the surface which might otherwise produce perceptable serrations on the surface of the bar as it is extruded.
What is desired to be protected by Letters Patent is:
1. In the process of producing a milled nonsoap detergent in bar form consisting essentially of detergent material and a plasticizer, said detergent material being a water-soluble salt of an organic sulfuric reaction product having in its molecular structure a radical selected from the group consisting of sulfonic and sulfuric acid ester radicals and said plasticizer being a normally solid ether-alcohol fatty acid ester which dissolves slowly in water, the steps which comprise drying the detergent material to a moisture content of not more than by weight, incorporting up to 20% by weight of said plasticizer, heating the resulting mass to a temperature between 110 and 170 F. to render the same plastic and workable but insufficient to cause liquefication of the same, and subjecting said mass while thus heated to a plodding treatment to form a compacted, firm, cohesive detergent body.
2. In the process of producing a milled nonsoap detergent in bar form consisting essentially of detergent material and a plasticizer, said detergent material being a water-soluble salt of an organic sulfuric reaction product having in its molecular structure a radical selected from the group consisting of sulfonic and sulfuric acid ester radicals and said plasticizer being a normally solid partial ester of a long-chain fatty acid and a polyhydric alcohol, the steps which comprise removing moisture from the detergent material to reduce the moisture content so that it is not more than 5% by weight, incorporating up to 20% by weight of said plasticizer, heating the resulting plasticized mass to a temperature between and F. to render it plastic and workable, and subjecting said mass while thus heated to a plodding treatment to produce a compacted cohesive detergent body.
3. In the process of producing a milled nonsoap detergent in bar form consisting essentially of detergent material and a plasticizer, said detergent material being a water-soluble salt of an organic sulfuric reaction product having in its molecular structure a radical selected from the group consisting of sulfonic and sulfuric acid ester radicals and said plasticizer being normally solid diethylene glycol monostearate, the steps which comprises drying said detergent materials to produce a detergent mass having a moisture content of not more than 5% by weight, incorporting up to 20% by weight of said plasticizer, heating the resulting plasticized mass to a temperature between 110 and 170 F. to render the same plastic and workable, and plodding said mass while thus heated to produce a compacted cohesive detergent body.
4. A process as set forth in claim 1 in which said detergent material comprises a water-soluble salt of the sulfuric acid ester of a high molecular weight fatty acid monoglyceride.
5. A process as set forth in claim 1 in which said detergent material comprises a water-soluble salt of alkyl aryl sulfonates.
6. A process as set forth in claim 1 in which said detergent material comprises a water-soluble salt of an alcohol sulfonate.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,356,903 Wood Aug. 29, 1944 2,462,758 Malkemus Feb. 22, 1949 FOREIGN PATENTS Number Country Date 477,521 Great Britain Dec. 28, 1937