US2982735A - Detergent milled bar and process of preparing same - Google Patents

Description

May 2, 1961 J, BLINKA ETAL 2,982,735

DETERGENT MILLED BAR AND PROCESS OF PREPARING SAME Filed Sept 8, 1955 B I00 I00 y... .l

A E L; 75 75 l LU O O m '5 -7 5 a X 3 5o 50 V Q g y 2 U 25 UJ 0 25 v '1 DJ o I 0 4o 60 so aoo TEMPERATURE C wafim,afi M16. 1' 60mm United States Patent DETERGENT MILLED BAR AND PROCESS OF PREPARING SAME Joseph Blinka and Preston W. Grounds, IL, Cincinnati, Ohio, assignors to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio Filed Sept. 8, 19ss,'ser. No. 533,081

12 Claims. or. 252-121 nary toilet soap, having what is referred to'in the art as a draggy feel. Furthermore, bars of this type usually have tendency to smear or develop a slimy outer surface when left in contact with water, which detracts markedly from the appearance of the bar,'nec'essitates frequent cleaning of the soap dish, and results in excessive waste.

We have discovered that these and other defects of starch filled detergent bars may be overcome, and the characteristics of such bars otherwise improved, if the starch be properly gelatinized as hereinafter described.

Further objects and features of the invention willbe apparent from the following description taken in connection with the accompanying drawing, in which:

Figure 1 is a graphical representation of the effect of temperature on gelatinization of certain starches, and

Figures 2 and 3 are photomicrographs of compositions containing starch in normal and gelatinized form, respectively.

If starch is suspended in water and heated, a gradual taking up of Water (gelatinization) occurs. This is described in Radley, Starch and Its Derivatives, 2d ed., vol. 1, pages 89 and 90. Figure 1, taken-from the publication by Radley, shows how the gelatinization of potato and corn starch proceeds We prefer to determine the extent of gelatinization by means of a microscope fitted with cross Nicol prisms. The ungelatinized particles show a birefringence when thus viewed. In the practice of the present invention, we prefer to gelatinize to the point B, Fig. 1, where all of the anisotropy as shown by birefringence has disappeared. As stated by Radley in speaking of gelatinization generally, some workers in the field consider the point of gelatinization to be the point A, where anisotropy disappears from the majority, of

the granules, but for use of the gelatinized 'starch in synthetic bar formulations, we find the characteristics we desire to be more fully developed if we gelatinize until all anisotropy disappears.

The starch used should be a normal (non-waxy) starch. The amylose {content of these non-waxy starches is reported to be from about 15 to'about 25 percent and this type of starch appears necessary for theattainment of the characteristics we desire. The Waxy starches, containing little or no amylose, do not yield a satisfactory product.

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to use in preparing our product than the untreated 1 starches. These oxidized starches may be gelatinized with much less water than the'untreated starch; normally a ratio of 4 parts of water to one of oxidized starch is suflicient in the presence of synthetic detergents and soaps, both of which are retarders of gelatinization; The oxidized starches are readily available from starch manufacturers I The compositions of our invention contain at least 10% of sodium soaps of fatty acids, preferably from talloW or coconut oil. These may be added in whole or in part to the aqueous solution and dispersion used to gelatinize the starch, butit is conducive to, better appearance if these sodium soaps are added after the starch preparation has been dried.

Our preferred method for gelatinizing the starch is to add to a mixer, commonly called a crutcher in the soap industry, enough hot water so that the mix will contain from about 55 to about of water when all ingredients including the synthetic detergent that are to go into the crutcher are placed therein. The synthetic detergent or detergents and any other ingredients that it is desirable to add at this time are then added and dispersed in the water. The oxidized starch is then added, and thoroughly dispersed with an auxiliary high speed mixer. On a pilot plant scale this may be accomplished with a hand-held, motor driven, propeller type mixer.

The crutcher is then run with the regular agitation. The mix is, roll driedand the completion of the gelatinization of the starch takes place on the rolls. The temperature required to efiect the completion of gelatiniza tion is achieved when the rolls are supplied with steam at about 60 lbs. pressure, and will vary with different starches. As indicated in Figure 1 of the drawing, gelatinization of cornstarch may be effected at about C. and of potato starch at about C. Time is, of course, a factor and, generally speaking, lower temperatures may be employed when the starch is heated for a longer period of time.

7 Figure 2 shows the appearance of oxidized starch in a crutcher mix. The dark cross dividing each granule into four parts is typical of the birefringence shown by ungelatinized starches. Figure 3 shows the complete disappearance of birefringence in the finished bar.

The dried crutcher mix may be milled, extruded .and stamped in conventional soap making equipment. If the sodium soap was not added to the crutcherit should be added before milling. -The sodium soap may be added as dried flakes or pellets, or part of it may be added as neatso'ap containing about "30% water if the dried mix dried mixin the 'amalgarnatore -a device for mixing materials with dried soaps. An amalgamator is commonly used to mix perfumeand' coloring matter with soapsbefore milling. In smallscalework, suchas some-dcscribed hereafter, the amalgamator may be dispensed The normal starch maybe brought-to the desired conditionin a number of waysf It may be suspended in water and heated. This has the disadvantage of introducing a large amount of=water into the composition because normal starch will not-gelatinizeunlesssuspended .inmore than about ,15 times its weight of water.

with and the mixing achieved by an extra pass thru'thev milling rolls. I The synthetic detergents that may be employed ilr-the practice of the invention are the normally solid synthetics,

commonly referred to as anionic organic sulfuric reaction products. Cationic detergents are not suitable, being incompatible with soap, and nonionic detergents are commonly either liquid or pasty,and ,areof ten nonlathering,

. of ethylene oxide.

20 minutes.

limited.

Alkyl glyceryl ether sodium sulfonate in which the alkyl is at least 50% dodecyl.

The alkyl sulfates, typified by sodium dodecyl sulfate.

The alkyl monoglyceride sulfates, such as coconut monoglyceride sodium sulfate. (These are preferably not used with alkaline builders.)

The alkyl monoglycol sulfates, such as coconut ethylene monoglycol sodium sulfate.

The alkyl monoglyceryl sulfonates, such as coconut monoglycerol sodium sulfonates.

The isethionates-RCOOC H SO Nawhere the RC preferably represents acyl radicals in a mixture of fatty acids from oils of the coconut group; for example coconut fatty acids esterified with isethionic acid and neutralized with sodium hydroxide.

By oils of the coconut group we mean to.designate vegetable seed or nut oil having at least 50% by weight of the combined fatty acids as lauric and/or myristic. Practically all of these are derived from nuts of the palm family such as coconut oil, palm kernel oil, tucum kernel, and babassu nut oil.

The methyl taurines RCONCH C H SO Na, where RC O preferably represents acyl radicals in a mixture of fatty acids from oils of the coconut group, e.g. sodium salt of coconut acid amide of N methyl taurine.

The sulfo acetates ROOCCH SO Na, where R preferably represents alkyl radicals contained in fatty alcohols derived from an oil of the coconut group specifically the sodium salt of coconut sulfo acetate.

Detergents made by sulfating and neutralizing the compounds made by reacting a coconut fatty amine with hydroxy acetic acid.

The alkyl benzene sulfonates, where the alkyl is a keryl or a polypropylene of C9 to C are satisfactory physically, if their tendency to exhibit a sticky feel is'not objectionable under their circumstances of use.

There may be used 'with the normally solid anionic detergents listed above, a limited amount of pasty or even liquid synthetics such as the nonionic synthetics.

In the following examples the quantities are given on the pure basis, that is, water and sodium chloride and sulfates have been subtracted from the gross weights used.

Example 1.-700 ml. of hot Water were added to a 1000 gram crutcher. To this was added 45 grams of sodiumsalt of middletcut coconut alcohol sulfate containing about'65% C alcohol and 21 grams of the Sulfated and sodium neutralized reaction product of lmole of the same middle cut coconut alcohol and three moles 30 grams of. sodium soap of 80% tallow, 20% coconut oil was then added and 60 grams of sodium coconutoil soap. .After these were dispersed,

there was added 18 grams of sodium tripolyphosphate and this was dissolved. Then there was added 103 grams of Hercules No. sizing starch (oxidized) made by Corn Products Refining Co.; the starch was dispersed by high speed agitation and mixing was continued for about The temperature was about 150 F. during this mixing. The mix was roll dried on a roll heated with steam at "about lbsl-steam pressure at the rate of 1 lb. of dried product iper hour per square foot of .roll and examined forungelatinized starch. No birefringence was noted. The mix was milled, extruded from a small plodder and stampedinto 80 gram bars. The finished bar contained about 1% "of sodium chloride and sodium sulfate and hada moisturecontent'of 12%.

These bars were good in lather and excellent in resistance to smear when soaked injwater overnight. The smear test was made by'cutting 'ofi'the' stamped fac'eof a 7 containing about C alcohols.

4 bar to provide a flat surface. The bar was then soaked 16 hours in 70' water. The bar was weighed and then the soft smeary cut surface wiped off with the full force of the forefinger. The bar was then reweighed. The loss in weight compared to that of a similar bar of soap or detergent known to be satisfactory when tested in the same manner, is a measure of smear.

Example 2.This composition was similar to Example 1, using the same ingredients, the synthetic detergents being increased over Example 1 and the starch being correspondingly decreased. The preparation was carried out exactly like Example 1, except for the change in proportions. The final product had the compositiondry basis:

. Percent Sodium middle cut coconut alkyl sulfate 20 Sodium salt of the sulfated product of reacting 3 moles of ethylene oxide with 1 mole of middle The final bar had 13% moisture. This bar lathered as well as that of Example 1, and was practically the same in smear when soaked overnight in water.

The sodium middle cut coconut alkyl sulfate in this example may be replaced by sodium alkyl benzene sulfonate where the alkyl is polypropylene averaging about 12 carbons in the radical. The bar with alkyl benzene sulfonate performs as well as the one with coconut alkyl sulfate but it has a slightly sticky feel to the hands.

Example 3.-This was prepared similarly to Example 1. The finished product analysis, dry basis was Making parts.

To these 100 parts were added on the milling rolls 3.5 parts of middle cut coconut alcohol. The stamped bar contained 12.2% of water. The coconut alcohol, a suds builder, improved the latherso that it was slightly better than that of Example 2. The overnight smear was almost the same as that of Example 2.

Example 4.'About 650 ml. of hot water at about 200 F. was added to a 1000 gram crutcher. To this was added 45 grams of sodium middle cut alkyl sulfate There was then added 9 grams of the sodium'salt of the sulfated reaction product of 3 moles ofethylene oxide to 1 mole of fatty alcohol made from tallow. After these were well dispersed, there was added 103.5 grams of Hercules #55 sizing starch made by Corn Products Refining Co. The starch was dispersed with rapid agitation and then heated for about 20 minutes at about F. The mix was roll dried, at about 60 lbs. steam pressure on the rolls at the. rate of one pound of dried product per square foot,

of the 106v" mi'mt of alkyl sulfatepthis example did not lather quite as well as the product of Example 3, and the overnight smear was betterthan that of Example 3, showing that the properly gelatinized starch produces a bar that will hold together when soaked in 70 water for 16 hours. A bar with ungelatinized starch for example will lose in an overnight smear test, about twice asmuch weight as the same formula made into a bar with gelatinized starch.

Example 5 .There was added to a 1000 gram crutcher about 650ml..of hot water at about 200 F. To this there was added 45' gramsof sodium salt of middle cut fatty alcohol sulfate. To this was added 15 grams of sodium salt of the sulfated reaction product of 10.moles of ethylene oxide to 1 mole of tallow alcohol and 11.4 grams of sodium coconut oil soap. There was then added 45 grams of sodium tripolyphosphate. These were dispersed by mixing and there was added 84 grams of Hercules #55 sizing starch. The temperature had dropped to about 150 F., but this was enough to require rapid agitation to prevent the starch from gelatinizing in lumps. After the starch was well dispersed, the normal agitation of the crutcher was restored and the mixing continued for about 20 minutes. The mix was roll dried at about 60 lb. per square inch steam pressure in the rolls, at the. rate of one pound of dried product per square foot of roll per hour. This was enough to complete the gelatinization'of the-:starchj There was added on the mills- 78.6 grams of sodium soap of 80% tallow, 20% coconut oiland 7.5 grams of middle cut coconut oil fatty alcohol. After milling, the bars were extruded and stamped. The bars contained l-8%' moisture. The bars were excellent in lather, but superior in resistance to smear, upon being soaked overnightin water, to those made with ungelatinized starch.

Example 6.-This was prepared like Example 5, but the proportions were different. The finished bar cont i d I I Sodium salt .of middle cut coconut alcoholsulfate parts by weight 20 Sodium salt of the sulfated reaction product of '3 moles of ethylene oxide to S1 mole of tallow alparts 6.5

cohol Sodium soap of 80% tallow, 20% coconut oil parts 18 Sodium soap of coconut oil do 12 Sodium -tripolyphosphate do 3 15 Salts and miscellaneous do 5.8 Starch (Hercules #55) don 20.2 Middle cut fatty alcohol do 2.5 Moisture o 13.8

This bar lathered well, and was satisfactory in smear tests.

Example 7.In this example parts are shown by weight.

20 parts sodium alkyl glyceryl ether sulfonate (middle cut coconut alkyl) 1 parts sodium soap of 80% tallow, 20% coconut oil parts sodium coconut oil soap 10 parts calcium hydrated soap of 80% tallow,

coconut oil parts oxidized starch 10 parts water 10 parts miscellaneous salts.

The sodium alkyl glyceryl ether sulfonate is dissolved in enough water to constitute 60 to, 75% final mixture in a crutcher. The 80% tallow, 20% coconut soap to be made into calcium soap is then dissolved in the crutcher. The equivalent amount of calcium'chloride is added and stirring continued until dispersion. occurs. is then added and dispersed with high speed agitation. After dispersion, the agitator is run at normalspced until a good mix is obtained. The crutcher mix is roll dried; The sodium soap of 80% tallow, 20% coconut oil is added as pellets and the sodium coconut soap as kettle soap to the amalgamator. After mixing, the lot is milled, plodded, and stamped. The hand lather was satisfactory.

. In place of calcium chloride, magnesium sulfate in equivalent amounts stoichiometrically may be used. If it is desired to produce a mixture of calcium and magnesium soaps the chlorides of calcium and magnesium should be used to avoid the formation of relatively insoluble calcium sulfate.

The sodium salt of the coconut ester of isethionic acid may be used in place of the alkyl glyceryl ether sulfonate in the formula of Example 7 and will produce a bar of equivalent performance.

While these examples contain synthetic detergents at the 20% level, it will be understood that the synthetic detergent may vary between 15 and 40% depending upon the qualities desired in a bar, and the sudsing power of the synthetic detergent used. a

The detergent compositions described above are not limited to the particular detergents described. The synthetic detergents described above in the enumeration of normally solid syntheticscan be substituted'for detergents used in the above examplesv with substantially the same results.

We have prepared bars with as little as 15% starch as the only inert binder-filler and find them satisfactory, however the lowering of the starch requires. the increasing of the soap or the anionic synthetic detergent or both. Increasing the soap increases the tendency to curd in hard water, and increasing the synthetic adds to the cost, with no improvement in performance. 15% of starch is about the lower limit in which starch is useful.

The upper limit is set by the fact that about 25% of active (synthctic detergent plus soluble soap) is the minimum for effective performance' There is usually about a'minimum of 5% of miscellaneous inorganic salts, so the upper limit for starch in a bar is about 70%, although most of our compositions will be in the range of 15 to 45%.

The soluble soap is a desirable ingredient in a bar containing anionic synthetic detergent and starch. The soluble soap will normally. be principally a sodium soap of coconut oil type or a sodium soap of tallow and coconut oil type. When the anionic synthetic detergent lathers'slowly as it is used, coconut soap is preferred -as..it acts .to speed up lathering. vThe-soluble soap will normally constitute 10 to 35% ofour compositions. The. soluble soap may be all tallow .soap if speed of lathering is not a primary objective. The sum of the synthetic and soda soap will normally be not more The synthetic bar containing properly gelatinized starch may be prepared by spray drying a detergent- The starch I starch crutcher mix instead of roll drying. When this is done, it is desirable to pass the crutcher mix thru a process step involving vigorous agitation and disintegration, before spray drying. The period of heating in a spray tower is short as compared to roll drying and the gelatinization and rupturing cannot be easily carried out in the crutcher alone, because of the retarding effect ofthe soap and synthetic upon gelatinizing and rupturing. A suitable agitation and disintegration may be achieved by passing the crutcher mix thru a homogenizing valve at 3000 p.s.i., before spraying into the drying tower.

Another method of gelatinizing the starch is to precook it before mixing with the detergents. The oxidized starches are the most useful in this procedure as they can be cooked with a water to starch ratio as low as 2 7 to 1, although a ratio of 4 to'l 'ispreferred in the pres ence-"of synthetic detergents which retard gelatinization, whereas untreated corn starch will require a ratio of about 15 to 1.

Theprecooking of oxidized starch must be done with good agitation to prevent lumping. The mixture of the precooked starch and soap-detergent dispersion will have to be quite thoroughly carried out, otherwise, starch will appear in the finished bar as grit.

The moisture content of barscontaining gelatinized starch soluble soap and a synthetic detergent should be controlled between the lower limit for plasticity and the upper limit for softness. These limits will normally be between 10 and 15%, although as little as 5% moisture may be used when the anionic sulfonic reaction product used isof awaxy nature and is used at a high level, say 35%.

It will be preceived that starch may be properly gelatinized in a number of ways for inclusion in a bar containinga synthetic detergent and we do not wish to be limited to the methods herein disclosed. The prin cipal point to be observed is that the starch be gelatinized to the disappearance of anisotropy.

While the invention described and claimed herein resides in the use, as a binder and fi-ller for a detergent bar containing synthetic detergent and soap, of a starch which has been fully gelatinized while the proportionsof synthetic detergent and soap are not critical, the'utility of the invention is best demonstrated in detergent bars containing anionic synthetic detergent within the range of 15% to 40%, and soap in the range of 10% to and in which theamount of starch is not less than 15% nor more than 70% otthe bar, the percentages being by Weight. soap preferably constitutes between 35% and 60% of the bar and the moisture content is preferably not less than 5% andnot more than 15%.

While the soap bar of thepresent invention comprises essentially detergents of theolass described Withstarch, it will be appreciated thatthe incorporation in the bar of commonly used perfumes, organic and inorganic builders iscontemplated as part of. the instant invention.

It will be appreciated that'reference herein to a syn thetic detergent is intended to include mixtures of detergents of difiierent types. I

What is claimed is: Y

'1. A detergent milled bar having a characteristic soaplike feel, comprising 10% to 35% normally solid, watersoluble sodium soap and 15% to 40% of a normally solid anionic synthetic detergent comprising a water.- soluble, alkali metal salt of an organic sulfuric reaction product and a gelatinized non-waxy starch, said gelatinized starch being characterized by the disappearance of anisotropy and constituting not less than 15%, nonmore The total amount-of synthetic detergent and than 70% of the bar, the sum of said syntheticdetergent and said sodium soap being between 25% and 65%.

2. The detergent bar of claim l'in which the gelatinized starch is present in the range of 15% to 45%, the sumof'said synthetic detergent and said sodium'soap being between 35% and 3. I The detergent bar'of claim. 1' in which the moisture content is not less than 5% and not'more than 15%.

4. The detergent bar of claim 1 in which the gelatinized starch constitutes not less than 15%, nor more than45% of the bar.

5.The deter-gent bar of claim 1 in which the'normally solid, water soluble sodium soap is. of fatty acids selected from the group consisting of tallow fatty acids, coconut oil'fatty acids, and mixtures thereof.

6. In-the process of preparing a milled toilet bar consistingessentially of 15% to 40% ofa normally'solid synthetic anionic detergent comprising a water-soluble.

alkali metal salt of anorganic sulfuricreaction product, 15% to 70% gelatinized non-waxy starch and 10% to 35% normally solid, water-soluble sodium soap, the sum of saicl'synthetic detergent and said sodium soap being between25% 'and the steps which comprise agi: tating and dispersing starch and synthetic detergent in water, the weight of said water being vfrom about 2vto about 1'5.times the weight of said starch, and suflicient in amount to permit complete ,gelatinization of said starch, heat drying the mixture, effecting substantially complete'gelatinization of the starch to disappearance of anisotropy, milling and extruding the mixture and stamping same into a bar, and at any stage prior to milling and extruding, adding sodium soap to the mixture.

- 7; The process. of claim 6 in which said starch is nor mal starch and it is dispersedin about 15 times its weight of water.

"8. .The process of claim;6 inwhich said starch is oxidized starch and it is dispersed in about.2 to about 4 times its weight of water.

9. The process of claim 6 in which the mixture of synthetic detergent, starch and water is roll-dried with the aid of steam at about 60 pounds per square inch pressure 10. The process of claim 6 in-which the sodium soap is added to the mixture of water, starchand synthetic detergent.

'11. The process of claim 6 in which the sodium soap is added to the 'dried mixture. I

12. The process of "claim 6 in which a portion of the sodium'soapis added to the mixture of synthetic detergent, starc'h and'water and the re'm'aindenof the sodium soap is added to the dried mixture.

'RierencesCited in the file ofithis patent .UNITED STATES PATENTS 1,438,169 Hoyt Mar. 23, 1948 2,714,093 'Blumenthal July 26, 1955

Claims (1)

1. A DETERGENT MILLED BAR HAVING A CHARACTERISTIC SOAPLIKE FEEL, COMPRISING 10% TO 35% NORMALLY SOLID, WATER, SOLUBLE SODIUM SOAP AND 15% TO 40% OF A NORMALLY SOLID ANIONIC SYNTHETIC DETERGENT COMPRISING A WATERSOLUBLE, ALKALI METAL SALT OF AN ORGANIC SULFURIC REACTION PRODUCT AND A GELATINIZED NON-WAXY STARCH, SAID GELATINIZED STARCH BEING CHARACTERIZED BY THE DISAPPEARANCE OF ANISOTROPY AND CONSTITUTING NOT LESS THAN 15%, NOR MORE THAN 70% OF THE BAR, THE SUM OF SAID SYNTHETIC DETERGENT AND SAID SODIUM SOAP BEING BETWEEN 25% AND 65%.

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