CA1125621A - Cast detergent-containing article and method of making and using - Google Patents

Abstract

M&G-163.331/USA

CAST DETERGENT-CONTAINING ARTICLE
AND METHOD OF MAKING AND USING

ABSTRACT OF THE DISCLOSURE
Solid cast detergent-containing articles are produced for use in automatic washing machines. A liquid detergent composition is cast into a mold where it is allowed to solidify.
The solid cast detergent, surrounded on all but its upper surface by the mold, is used in automatic washing machines. The cast detergent composition includes an alkaline hydratable chemical and optionally further includes one or more preformed cores or plugs comprising an available chlorine source, a defoamer, or the like.

Description

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FIELD O~ T~IE INVENTION
This invention xelates a novel solid c~st det~rfJent-containing article which is particularly useful in institutional dishwashing machines and industrial washing machines. Another aspect of thic invantion relates to a method Lorproducing t~e dPtergent-con~aining article. Ano~her aspect of this invention xelates to a method for using the detergent-containing article.
Still another aspect of this invention relates to a method for iso-lating reac~ive and incompatible components with~n a solid cast detergent ~o minimize-interactiOn between them during manu~actuxe, storaga, and dispensing.

DESCRIPTION OF THE PRIOR ART
Conventional institutional and industrial spray washi~
machines employ liquid or powdered det:ergents which are generally added to the wash tank by means o an automatic dispenser s~stem.
All forms of-'such detergents, whether li~uid or solid,. have stability pro~lems and othex problems associated with their manu-facture, dispensing, and use~ These problems have been discussed extensively in prior art publications and patent literature, and it is not practical to do anything more ~han summarize these dis-cussions~ In the early days o~ the development of solid d~tergents r when these detergent products were relatively low in per~ormance compared to the products of today, the problems were les~ severe~
However, ~he advent of high perormance products, stimulated in part by increased esthetic and sanitar~ standards and a demand for shorter wa~htimes has generally been characterixed by the development of more complex detergent compositions which ~re more .

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hazardous to the user, less stable, and more difficult to dissolve in a satisfactorily uniform manner.
For example, higher performance solid detergents generally means higher alkalinitv (e.g. grea-ter concentra-tions of sodium hydroxide) -- higher even to the point of ~ -posing safety hazards to the user. Historically, detergents used for warewashing have been relatively low in alkalinity.
The extensive use of aluminum trays and utensils, the presence of soft metals in wash pump impellors and other factors generally prevented the use of high alkalinity detergents. ;
Recently, however, there has been a trend toward the use of high alkalinity, higher performance products. This trend has been partially the result of the increased usage of stainless steel and corrosion resistant plastics in the production of utensils. In addition, the aforementioned increased standards ~ ~
and shorter wash times (usually ten seconds or less) required ~;
by the increased volume of business in eating establishments have created a demand for these higher performance products.
In addition to alkali metal hydroxides (e.g. sodium hydroxide), chemicals used in high performance products, parti-cularly for hard surface cleaning (e.g. warewashing) include phosphates, silicates, chlorine containing-compounds, defoamers and organic polyelectrolyte polymers. See U.S. Patent No.
3,166,513, issued Jan. 19, 1965 (Mizuno, et al), U.S. Patent No. 3,535,285, issued Oct. 20, 1970 (Sabatelli, et al), U.S.
Patent No. 3,579,455, issued May 18, 1971 (Sabatelli, et al), U.S. Patent No~ 3,700,599, issued Oct. 24, 1972 (Mizuno et al) and U.S. Patent No. 3,899,436, issued ~ug. 12, 1975 (Copeland, et al). The alkali metal hydroxides in these compositions are : ;:

, .~ . : ..... .. .

very e~fecti-v-e i~ removing ~ost stubborn food soils, but a source O f available chlorine is usually included to control ~ood s~ains, such as tea and coEfee stains. The deLo~.ler i5 usuall~ included to control foa~. created by a proteinaceous soil and.sæponi~i.ed fats. The use oE chlorinated cyanurates as a source of available chlorine in detergents used to clean hard sur~aces is disclosed in U.S. Patent No. 3,166,513, issued Jan. 19, 1965 ~Mizuno, et al), U.S~ Pa~ent Nol 3,933,670, issued JanO 20, 1976 ~Brill, et al~, U.S. ~atent No. 3,936,386, issued Feb. 3, 1976 ~Corliss, et al)~
These patents also describe various means for obtaining storage stable chlorine bearing detergents. The use of defoamers in detergent compositions is disclosed by U.S. Patent No. 3,048,54~, issued Aug. 7, 1962 ~r~lartin, et a'1~, U.S. Patenk No. 3,334,147, issued Aug. 1, 1967 (Brunelle, et al), and U.S. Patent No.

3,442,~2, issued May 13, 19~9 (Rue, et al).
b~e problem associated with detergents containing both.

an active chlorine souxce and an organi~ ~efoamer has been a suhstantial loss of available chlorine in a relatively short period o time, This problem is described in a number of the above references and in the article by R~ Fuchs, ~ a Polkowski, and ~arfagno, "Aggo~nerate~ Automati~ Dishwasher Deter~entsp"
Chemical Times and Trends, Pages 37-~2 ~O~. 1977~. One solutiQn to this problem has been to absorb the organic defoamex onto an inorganic carrier particle, t~.us "encapsulating" the defoamer&
see U.S. Patent No~ 3,306,858, issued Feb.28, 1967 (Oberle)~ .
~ile a chlorine stability problem is present in low alkalinity detergents containing defoamers, the problem is more acute wi~h hish alkalinity de~ergents because many defoamers and chlorine-containing compounds are not stable in the presence of highly alkaline chemicals such as sodium hydroxide.

In addition to the chlorine stability problem, several additional problems have existed with high performance powdered detergent compositions which have been used in institutional and industrial washing machines. One of these problems has been caused by differential solubility of the detergent components. ~ot all of the components of standard detergents dissolve at the same rate or have the same equili- -brium solubilities. For example, a fine, soluble particle such as sodium dichloroisocyanurate dihydrate, a common source of availa~le chlorine, will dissolve much more rapidly -than sodium tripolyphosphate, a common detergent component.
Thus, when a dispenser is charged with a powdered detergent containing both of these components, the first effluent from the dispenser will usually be over-rich in available chlorine while the last effluent before the dispenser is recharged will usually be poor in available chlorine.
Another type of differential solubility problem exists with many common defoamers. Many defoamers have an oily consistency and are sparingly water soluble. When detergents containing these defoamers are dispensed from a conventional water-in-reservoir dispenser, the oily defoamer floats to the top and feeds the wash tank in an erratic fashion.
Another problem may exist with a powdered detergent if its components are of different particle sizes and densi-ties. Variations in particle size and density between com-ponents may lead to segregation during manufacturing, ship-ping, and handling. Even when uniform distribution can be achieved during manufactur~ -. ~

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ing, handling and shipping may cause seg~eqation. Segregation 7 eads to n~n-uniformity in the composition of the d~tergen~
~hen it is withdr~wn fro~ the contain~r. ~gglo~.eration of the components has been used to minimize the segregation problem.
Ho-~;ever, the use of agglomera-tion usually requires re~ycling of any particles ~hich are too larg2 or too small, which can be a signi~icant percentage of the ~roduct.
Returning again to the safety hazard pro~lem, one commonly used approach involves dispensing powdered or liquid detsrgents directly from their shipping container~
In any event, it is desirable for safety and convenience to minimize contact between the user and the high-per~ormance detèrgent composition, and such lessened contact can be one or ~he many benefits of automatic dispensingL In ~he case of liquid de-tergents, it is relatively easy to pro~ide an automatic dispensing system and m~thod~ For example, liquid detergents can simply be pumped into the wash tank or reservoir directly from their shipping .containers. - . : . - .
Solid detergents twhich can be in ~ri~uette, or, m~st typically, in powdered form) present much more complicated auto-matic disDensing problems~ Several approaches have been devised for attacking ~hese problems -- ~hat is~ for utilizing sQlid phas~
det~rgen~s wi~hout losing the benefits of automatic dispensing.
In one appxoach, detergents used in large conveyor type machines are dispensed direc~ly fxom their shipping containers by means of a dispensing system similar to that described,in U~SD Patent o. 3,595,438, issued July ~7~ 1971 (Daley, et al). The shippinc~ ~
containex is inverted and placed over a detergent dispenser xes- :

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ervoir and a water spray is used to dissolve the detergent from the drum as needed. A system for dissolving powdered detergent from a five to ten gallon capacity shipping pail is also known, see U.S. Patent No. 4,020,865, issued ~ay 3, 1977 (Moffat, et al). In short, the solid powdered detergen-t in the shipping container is not in a form which normally would be introduced directly into the wash tank of the washing machine, lt is generally preferred in the art to con-vert the powder into a liquid, e.g. by dissolving the powder with water in a special apparatus designed to carry out the dissolving step.
The dissolving apparatus need not be physically remote from the washing machine. Indeed, it is a common practice to mount dissolving/dispensing devices directly above -- or on the side wall of -- the wash tank of the machine. One typically used type of machine-mounted dis-penser i5 the so-called water-in-reservoir type. (The water-in-reservoir approach is not limited to machine-mounted dispensers, however; in machine-mounted applications, the water-in-reservoir dispenser is generally used in single tank warewashing machines.) Typically, the water-in-reservoir type of dispenser makes up a concentrated solution of deter-gent from the powder in the reservoir by means of swirling action or agitation provided by incoming water. The concen-trated solution is delivered directly to the wash tank by gravity or through a delivery tube. The concentration of the detergent in the wash tank can be maintained at a preset level by means of a conductivity sensing controller similar to that described in U.S~ Patent No. 3,680,070, issued July 25, 1972 (Nystuen).

Various other t~pes of devices will dissolve and dis~ense po;~dered detergents and can be mounted directly on the T~ashing mar~i~e. For example, U~S. Patent No~ 4,063,663, issued Dec. 20, 1977 (Larson, et al) describ~d a t~pe of dispenser in ~hich the po~dered detergent is placed over a conical or hemispherical screen and an a~u~ous spray from beneath the screen is used to dissolve the dekergent~ The concentrated solution produced by the spra~ is collected and directed to the wash tank~
This dispensex differs from the water-in-reservoir type in that there is no water standing in the p~wder dispenser and ~h~
bulk o~ the powder remains dry. Otherwise, this type of dispenser operates in a manner similar to the water-in-reservoir type.
A~ong the other types of powdered detergent dispensers are small dispensers which hold from f.our to six pounds o~

aetergent. The hopper of such dispen~;ers can be ~illsd from detergent-containing drums by means o~ a scoop or b~ the use o~
,..;~
srrall individual ~i.e. two pound) pouches of detergent.
Dispensing systems ~or washing systems consisting o~ multiple hoppers which are fîlled wi~h di~ferent chemic~ls or mixtures o~`chemicals are also known~
Dispensing systems for dispensi~g ~riquettes o~ det~r-gent are also known in t~a art. see U.s~ Patent Nos. 2,3~2,163

2,382,164, 2,38~,16S all issued August 14, 1945 to Ma~`~ahon and u.s. Patent No. 2,412,819, issued Dec. ~7, 1946 tMacMahon)~ The detergent briquettes are dispensed ~rom a modified water-in~

reservoir round, pot-shaped dispenserO The briquettes ~usuall~

ree) are held in a m.2sh basket which fo~ns a slot a~out a / ( ~Z56Z~

1 1/4 inch~s ~id~ across the dia~e-ter of th- pot. The dissol~ing a~tion is provided by a strea~ of t~ater directed against the lo~.~er-~ost briquette and from the swirlins action of ~Jater around the su~erged portion of the lower-most briquette. Li'~e-the water-in dispenser t~pe devices, water is left standing in the reservoir.
T:ni5 t~pe of system has the advantage of making it visually possible to determine when the detergent dispenser reser~oir needsreplenishing.
The MacMaho~ patents also disclose detergent briquette compositions and methods of manufacturing the briquettes. The br~quette compositions and the methods o~ manufacture which are disclosed appeax to require the presence of a silicate and ~risodium polyphosphate or sodium carbonate. ~etergent bars or cakes comprising a signiicant level of an or~anic detergent. and.
tripol~phosphates are also known~ Se~ U.S. Patent No. 3,639,~86, issued Feb. 1, 1972 (Ballestra, et al)~ Compressed tablets c3n-taining detergents are also known, see U.5~ Patent No. 2~738,323, issued Mar. 14, 195~ (Tepas, Jr.) and U.S. Patent-No. 3,417,0~4, iss.ued Dec~ 7, 1968 tGoldwasser).
In t:he ie~d of dispensing solid detergen~ to con ventional institutional and indust~ial washing ma~hines for spray cle~ ing of hard surfaces ~e.g. warewashin~, the briquette de~ergent approach doPs: not appear to have attained the same de~ree of commercial success as powdered deterge ,ts.

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SUMMARY OF THE INVENTION
-It has now been found -that the chlorine stability, differential solubiltiy, segregation, and safety problems described above can be minimized by forming a solid cast detergent in a disposable mold and dispensing or using the ~ .
detergent directly from the mold/cast detergent combination.

That is, the combination of the cast detergent and the dis-I~J
posable mold in which it was formed provides an article of commerce capable of dispensing dissolved solids from substan-L~l tially only one surface -- the surface which was the free or unsupported surface casting in the mold. This detergent u~
article can be desiqned or structured to further minimize chlorine stability and differential solubility problems, e.g.
by including the chlorine source and/or the defoamer as pre-formed plugs or cores encased in the cast detergent composi-tion.
Thus, the present invention involves a process for forming and a method for using a three-dimensional, solid cast detergent composition containing an alkaline hydratable solid component, at least one other solid component, and a receptacle-shaped mold surrounding and containing the deter-gent composition on all but one surface. The detergent com-position is normally formed by mixing and heating the com-ponents in an aqueous solution, allowing the solution to cool and thicken as hydration of the hydratable component or com-ponents occur, pouring the solution into a mold and allowing the mixture to solidify. The aforementioned preformed plugs or cores of additional components can be inserted in the mixture after it has been added to a mold and before it has solidified.

` - 10 -The cast detergent composition is left in the dis-posable mold in which i-t was cast and is used by placing the -~ mold in a detergent dispensing apparatus where the detergent is dissolved from the mold through the open portion of the ,~e mold by the use of a liquid spray.
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BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a partial cut-away side view of a dis-posable mold containing the cast detergent of this invention.
FIGURE 2 is a cross-sectional view of a disposable mold containing the cast detergent of this invention. The cast detergent includes a preformed plug or core comprised of an additional ingredient or ingredients.
FIGURE 3 is a top view of the article illustrated in FIGURE 2.
FIGURE 4 illustrates the article of FIGURES 2 and 3 placed in an apparatus for dispensing the detergent composition.
FIGURE 5 is a graph comparing the chlorine recovery for a cast detergent prepared according to this invention versus a conventional powdered detergent.

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; DETAILED DESCRIPTION
Raw Materials One necessary component for producing cast deter-gent compositions of the present invention is a hydratable chemical. The term "hydratable chemical" as used herein includes chemicals forming both discrete and continuous states of hydration and !' ( -~1%5GZ3L

thus rneans a che~ical which is capable o~ absorbing or com~ining.~ith .~ater (e .g . O . 2-20 ~oles of ~ ter per mole of chemicalj to for~ either ~ype or state of hydration. The hydratable chemical '~7ill normally be alkaline, that is, a one weight-percen. aaueous solution of the chemical will have a pH of ~reater than 7.0 at 23C. Since the detergent compositions used in this invention are highly alXaline, it is preferred that ~he hydratable component of the composition be alkal;ne in nature. Hydratable chemicals useful in ~he practice of this invention include al~al-me~al hydroxides, su~h as sodium hydroxids and potassium hydroxide;
silicates, such as sodium metasilicate; phosphates, particularly phosphates of the formula MO ~P03M~n or the-corresponding cyclic -compounds PO3M ~PO3Mt PO3M, wherein M is an.alkali metal and n ~t` `:
is a number ranging rom 1 to about 60, typical examples of s-~ch phosphates being sodium or potassium or~lophosphate and al~aline condensed phosphates such as sodium or potassium pyrophosphate, sodium tripolyphosphate,-~tc.; carbonates~ such . .
as sodium or.potassium carbonate; borates, suc~h as sodium bora~e;
zeolites, etc. Combinatit~ns of ~wo hydratable c:hemicals, ~or example, sodium hydroxide and sodium tripolyphosphate, have been found to wor~ particularly well in the practice of t~is inYen~ion~
A second necessary component of the detergent com-position of this invention is water. Water is used to ~oxm ~
solution containing the detergent components . the solution being cast into a mold and solidifying as the hydratable chemical or chemicals form a hydrate with the water. Water may b~ added as .
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~L25i~2~ , a separate ingredient or in combination with one of the other components, for example as an aqueous solution of 50~ sodium hydroxide.
To obtain the advantages of this invention, at least two solid components are needed. If only one solid component were used, differential solubility and segregation problems would not exist and there would be few advantages to forming a cast composition. The advantages of a cast deter-gent composition over a conventional powdered detergent com-position are described more fully hereinafter.
In additlon to those components previously described, other conventional detergent components and fillers can be included. For example, it is common to include a source of available chlorine and a defoamer. Many chlorine sources can be used including chlorinated isocyanurates r such as sodium dichloroisocyanurate dihydrate, and hypochlorites, such as sodium and lithium hypochlorite. As more fully hereinafter described, when an available chlorine containing component is included in the composition of this invention it is preferably incorporated in the composition as a preformed plug or core.
Defoamers are also normally included in detergent compositions.
Typically, a "defoamer" is a chemical compound with a hydro-phobe/hydrophile balance suitable to reducing the stability of foam. The hydrophobicity can be provided by an oleophilic portion of the molecule (e.g. an aromatic alkyl or aralykl group; an oxypropylene unit or oxypropylene chain, or other oxyalkylene functional groups other than oxyethylene, e.g.
tetramethylene oxide). The hydrophilicity can be provided with oxyethyiene units or chains or blocks and/or ester groups - 13 ~

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(e.g. organo~phosphate esters), salt-type groups, or salt-forming groups. Typically, defoamers are nonionic organic surface-active polymers having hydrophobic groups or blocks or chains and hydrophilic ester-groups, blocks, units, or chains, but anionic, cationic, and amphoteric defoamers are known~ For a disclosure of nonionic defoaming surfactants, see U.S. Patent No. 3,048,54~, issued Aug. 7, 1962 (Martin, et al), U.S. Patent No. 3,334,147, issued Aug. 1, 1967 (Brunelle, et al), and U.S. Patent No. 3,442,242, issued May 13, 1969 (Rue, et al). Phosphate esters are also suit-able, e.g. esters of the formula RO tPO3Mtn ~, wherein n is as defined previously and R is an organic group or M (as defined previously), at least one R being an organic group such as an oxyalkylene chain. If a defoamer is included it may be included as a preformed plug or core, as more fully described hereinafter. If it is included as a preformed core or plug it must be a solid, or be capable of being combined with other components to form a solid, at room temperature.
Wax-like materials can be used to further isolate the chlorine source or defoamer in the core from the surrounding cast article.

~, The Detergent Composition The hydratable chemical or combination of hydrat-able chemicals will normally comprise at least 30~, and pre-ferably 60%, by weight of the cast detergent composition.
The water of hydration will normally comprise at least 15%, and preferably , .

. . . ` . :: . ', ' : ' : ~ , 5~

~5~, of th~ cast detergent compositio~. Performance improvin~
additives such a~ available chlorine producin~ components and defoamers will normally comprise minor amounts or the composition, - that is, less than 5~.
Typical three-component compositions of this invention can ~e formulated from (l) a phosphate or other hardness-pxe-cipitating or hardness sequestering agent, 12) an a~kali metal hydroxide, and (3~ water. Typical four or five component compositions would further include a defoamer and~ox a neutral inorganic salt ~aIkali metal halides, sulfates,etc.) and/or a chlorine source and/or a thickening agent, thixotrope, suspending agent, or th~ like.
Typical ~etergent composit:ions of this invention ~ .
.; employ:a ~ondensed alkali metal phosphate for the sequestering o hardness ~Mg and Ca ions~. However, alternati~es to ~he con~snsed phosphates are known; see, for example UrS~ Patent :: ~o. 3,53S,285, issued Oct. 20, 1970 ~Sabatelli, et a~), U.S~--Pat~nt No. 3,579,455, ~ssued May 18, I971 ~Sabatelli, et al~
U.S Patent No. 3,700,599, issu~d Oct. 24~ 1972 ~Mizuno, et al), and U.S. Patent Nc~ 3,899,436, issued Aug. 12, l~S ~Copeland, al).
~; ~ One ~mbodiment of the solid, cast de~ergent-containing article of this invention is generally shown by number 1 in FIGURES 1 through 3. The article includes disposable container :~ or mold 3 into which base detergent 2 was cast or allowed to solidify. During shipping, article 1 will normally include lid : ox ~over 5A Lid or cover S can be made of the same or si~ilar , 11256Z,L

m~te~ial as used to make mold 3. As ~ e explained subsequently, this material is ordinarily alXaline-~esistant, ~o~-breakable, ~nd ine:pensi~e. Expensive corrosion-rosistant metals or plastics can be used, if provision can be made for their re~lcling, b~lt "disposable" materials would normally be preerred for mos~
institutional uses~ As illustrated in FIGURE 2, the cast detergent composition is surrounded by and in contac~ with mold 3 on all bu~ the upper surface of the solid cast detergent.
In a preferred embodiment of this invention, c~st detergent base 2 will include one or more prPformed plugs or cores 6, as illustrated in FIGU~ES 2 and 3. At least one preformed plug will normally comprise a chlorine source. When a pluralit~
of pre~ormed plugs are used they will normall~ comprise di~rerent, incompatible lngredients. For example,one plug could comprise a chlorine source while a separate plug could comprise a defoamer.

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B~f incorporating a chlorine source in one preormed plug and a defoamer in a separate preformed plug, degradation of the chlorine source, and the resultant loss of avai~able chlorine, whi~h often occurs wh~n chlorine sou~ces and defbamers come in contact, can be mînimized. Thus, by incoxporat;n~ preformed plugs of incompatible ingredients in the solid~ cast detergen~
composition of this invention, the st2bility problems associate~
with many conventional p~wdered detergen~s can be minimized. To minimize reactivity between the base detergent and any materi.al added as preformed cores, the core material may be optionally encased in a film or material which would not react with the cDre .

~6-~;25~%~

material or the detergent base. This coating could be com-prised of a natural wax, a synthetic wax, a phosphate ester, or the like.
Some active chlorine sources such as calcium hypo-chlorite have been found to react very slowly at the plug-base detergent interface and would not normally need to be encased in a film or the like. However, other chlorine sources such as sodium dichloroisocyanurate dihydrate have been found to be more reactive, in which case a protective film would be beneficial.
Mold or container 3 can be made of any alkali-resistant material which can withstand moderately elevated temperatures, e.g. 150F., and which can be formed into and hold the desired shape. Since the mold is generally intended to be "disposable" (i.e. not intended for re-use as a mold), inexpensive materials are preferred such as thermoplastics, resin-impregnated heavy paper or cardboard, and the like.
Inexpensive but fragile materials such as glass or ceramics are less preferred due to handling or shipping problems, relatively flexible materials being preferred. Molds made of plastic (e.g. inexpensive thermoplastics) have been found to be particularly useful.

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METHOD OF MANUFACTURING
While the following process is described with refer-ence to specific components, it should be understood -that other components and similar processes can be used to form a detergent solution which can be cast into a mold and will solidify upon hydration of its hydratable component. A parti-cularly useful detergent composition of this invention is ~ , formed by heating about 50-75 parts by weight of a 50-75 weight percent aqueous solution of an alkali metal hydroxide, e.g. sodium hydroxide, to about 55 to 65C. While other alkali metal hydroxides may be used, sodium hydroxide has been found to be particularly useful and the following method of manufacturing will be described with respect to it.
Aqueous solutions of 50 weight percent sodium hydroxide are readily comrnercially available. Solutions containing higher weight percents of sodium hydroxide are also available (e.g.
73%) or can be produced by adding a desired amount of anhydrous sodium hydroxide to a 50 weight percent solution of sodium hydroxide. An aqueous solution of sodium hydroxide can also be prepared by mixing water and anhydrous sodium hydroxide in the desired ratio.
After the acqueous solution of sodium hydroxide reaches a temperature of about 55 to 65C., 30 to 40 parts by weight of anhydrous sodium tripolyphosphate are added to the solution. Since the sodium tripolyphosphate will not normally completely dissolve, it is ]cept suspended by continu-ous mixing. After the sodium tripolyphosphate has been added other optional fillers and components ma~ be added if desired.
The solution is then allowed to cool with continuous mixing.
After approximately ten to fifteen minutes the mixture will begin to thicken. As it begins to thicken, the mixture is poured into a receptacle-shaped mold to a level at least part way up the side molding surfaces. As the mixture continues to cool it wil:L solidify to form a cast composition. While solidification is due partially to cooling, it is belleved . ' ~ !
~ - 18 -., - ' .

~25~%~

that it is mainly due to the hydration of the sodium tripoly-phosphate or product derived therefrom and to a lesser degree, the sodium hydroxide. After it has solidlfied, the cast detergent is surrounded by an in contact with the mold on all sides except for its upper suface which remains exposed.
After the base detergent has been poured into the mold, but before it has solidified, preformed cores or plugs such as plug 6 in FIGURES 2 and 3 may be added. When a plug is added, the base detergent is allowed to solidify around it and retain it in place. While any shape or size plug could be used, it is normally prefexred that the plug extend to the entire depth of the base detergent as illustrated in FIGURE
2. The plug should e~tend the depth of the solidified deter-gent so that a constant ratio of components can be maintained while the base detergent and the plug are dissolved during use.
An alternative method of including a separately formed plug or plugs could consist of using a mold comprising one or more smaller molds positioned within the larger mold.
The large mold would be filled with the cast detergent base while the smaller mold or molds would contain separate com-positions such as a source of avaiialbe chlorine or a de-foamer. The compositions could be cast into the smaller mold or preformed as a plug and "pressed" into the mold.

METHOD OF USE
The solid, cast detergent-containing article of this invention is normally used as illustrated in FIGURE 4.

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illustra.es deter~ent dispensing apparatus 10 which can be part oS a conventional institutional or industrial washing machine (not sho~ rti~le 1, includin~ base detergent 2 r preformed core 6, and container 3 i5 plac~d in an inverted position over sprav means 12 which is connectod to a water source 14. Wh~n water source 14 is turned on, spxay means 12 causes water to impinge on the eY~posed surface of detergent 2 and core 6. The detergent and the core dissolve and 10w ~hxough pipe 13 to the wash tank of the washing machine ~not shown~ Detergent base 2 and preformed core 6 can be formulated to dissol~e at substantially the s amQ rate ~nd thus supply the tank with a consistent ratio o~ ingredients.
By controlling the spray time the amount o~ detergent, ~nd ~hereby the concentration of detergent~ in the wash can be controlled~
The present invention will be further understood by ~ .
reference to the ~ollowing specific ~xamples which are i~lustrative of the composition, form and method of producing the solid, cast detergent-~ontaining article of this invention, It is to be understood that many variations of composîtion, ~orm and method :~ ~
: of producing ~he cast detergent would be apparent to those skilled ~ :
in ~he art. The foll~wing ex~ple~, wherein part5 and percenta~s ; are by w-ight unles~ otherwise indicated, are only illustr~tive.

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An 8.8 pound batch (approximately 4000 grams) of a solid cast detergent of this invention was prepared using the following procedure.
Eifty-five parts by weight of a 50 weight percent aqueous solution of sodium hydroxide were added to a labor-atory mixer provided with a stirring means and a heating means. The 50~ sodium hydroxide solution was heated to approximately 55-60C. Nine parts by weight of anhydrous sodium hydroxide were added to the solution. The solution was stirred until the anhydrous sodium hydroxide was com-pletely dissolved. The addition of the anhydrous sodium hydroxide had the effe^t of forming an approximate 57 weight percent aqueous solution of sodium hydroxide.
Thirty-six parts of anhydrous sodium tripolyphos-phate were added to the solution and the solution was mixed.
The tripolyphosphate did not completely dissolve but was held in suspension by mixing. Mixing was continued without heat-ing until the solution began to thicken, which was approxi-mately 10-15 minutes after the addition of the tripolyphos-phate.
After the mixture had thickened but while it was stiIl pourable, six pounds (about 2700 grams) were poured into a receptacle-shaped mold such as mold 3 in FIGURES 1-3, consisting of a slightly tapered cylindrical plastic con-tainer measuring about 6 1/2 inches (about 16.5 cm) at the major diameter (the open end) and about 5 1/2 inches (about 14 cm) at the minor diameter and about 4 1/2 inches (about 11.5 cm) in depth. The mixture was allowed to harden in the mold which took approximately 5 minutes.

~2~

The composition of the final cast product (in weight-%) was approximately:

36.5% sodium hydroxide 27.5% water 36.0% sodium tripolypho~phate 100 . 0%
While this product can be used as a detergent with-out additional additives, additional components can be included as illustrated in the following examples.

EXA~PLE 2 A product with the same composition as that des-cribed in Example 1, with the exception that 1 part by weight of the 50% sodium hydroxide was replaced with 1 part by weight of a defoamer, was produced. The defoamer was added following the addition of the sodium tripolyphosphate and was kept uniformly dispersed by continuous mixing until the mix-` ture was poured in the mold. At the time it was poured the mixture was sufficiently viscous so that a uniform dispersion was maintained.
The composition of the final cast product (inweight-%) was approximately:

36% sodium hydroxide 27% water 36% sodium tripolyphosphate 1% defoamer , 100% ~
. i A mixture was prepared according to the procedure described in Example 1. 53.57 parts of 50% sodium hydroxide, 8.77 parts of anhydrous sodium hydroxide, and 35.06 parts of anhydrous sodium tripolyphosphate were used. The mixture was then poured into the mold described in Example 1. Before the S6~

mixture completely solidiEied 2.6 parts of a preformed cir-cular "plug" measuring about 1 inch in diameter (about 2.5 cm) and about 3 1/2 inches (about 9 cm) in length, comprising a source of available chlorine, was placed approximately in the center of the mold. The length of the plug was such that it extended from the bottom of the mold to the surface of the mixture. The mixture was then allowed to harden around the plug.
The composition of the solidified cast detergent (in weight-%) was:

35.5% sodium hydroxide 26.8% water 36.1% sodium tripolyphosphate 2.6% chlorine plug 100. 0%
The available chlorine containing plug was prepared by forming a composition consisting of:

59.7 parts calcium ~ypochlorite - 65% available chlorine (HTHT from Qlin-Mathieson) 14.4 parts Veegum~ WG (from R.T. Vanderbitt Company, Inc.
25.9 parts dendritic sodium chloride 100. 0 "Veegum" is a trademark for inorganic suspending agents.
~ fter the three ingredients were mixed, plugs mea-suring about 1 inch ~about 2.5 cm) in diameter and about 3 1/2 inches (about 9 cm) in length, were made by filling an appro-priate size cylindrical die with the composition and subject-ing the die to about 2,000 psi in a hydraulic press. ~ ;~
Plugs containing available chlorine were producedfollowing the same procedure from the two following composi-tions:

A. 100 parts Lithium Hypochlorite 35% available chlorine - 23 -.

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B. 51.4 parts sodium~dichloroisocyanurate dihydrzte 14.~ par~s Vaegum i1G
34.~ pa~ts dend~itic sodiu~.. chloride lQ0.0 parts total Plugs produced from ~hese formulas w~re ~lso found to o~rfox~ satisfactorily in the articl~ of this invention.

EXA~IPLE 4 This example was design~d to illustrate ho~.~ plug 6 of I FIGURES 2 and 3 could be further isolated Srom the base deterg~ t_ One plug was made from each o~ the followin~ formulas by com-~: pression molding at a~out 2000 psi mold pr~ssurer 41O0g t59.9%) calcium hypochlorite - 65% available chlori~e 10.0g (14.3%) Veegum h7Ç . ~ . :
`18 0'~ ~25 8%) dendritic clalt ~ :

41. 5g ~5~ . 79~) sodium~9dichloroisocyanurate dihydrate ' lO.Og ~14O4~) Veegum WG
1~.0~ (25.9~) d~ndritic 3,alt , 6g.5g ~100~6) Both plugs were dipped in melted paraffin wax which was : held at ~ust above its melting point of 56.5C. so that a very : thin coating of paraf~in w~x was formed on the sides and one end ~: ~ of t~ plugO~. The wax was allowed ~o cool and harden. Th~ plugs w r~ then inserted into the cast d8~ rgen~ base of ~xample 2 following the procedure of Example 3. No visual indication of -~

`~: an~ reaction at ~he plug-de~ergent base interface was noted wit~
~ either o these plugs.

-~ ~ EXAMPLE 5 mixture was prepared following the procedure described in Example 2. 5~.57 parts of 50~ sodi~m hydroxida, ~D 77 par~
' of anhydrous sodium hydroxide, 35.06 parts of anhydrous sodium tripolyphosphate and 1 part defoamer were used. The mixture was then poured into the mold described in Example 1.
Before the mixture completely solidified, 2.6 parts of a chlorine containing plug similar to those described in Example 3 was added as described in Example 3.
The composition of the solidified cast detergent was:

35.0% sodium hydroxide 26.3% water 35.1% sodium tripolyphosphate 1.0% defoamer 2.6% chlorine plug 100.0%

~ EXAMPLE 6 :
A solid cast detergent of the same formula as that described in Example 5 was produced. ~owever, instead of mixing the defoamer with the base detergent it was added in the form of a plug. Thus, two plugs were used, one comprising a defoamer and the other comprising a source of available chlorine. The two plugs were placed near the center of the mold after the detergent was added, but before it solidified.
The composition of the solidified cast detergent was:

35.0% sodium hydroxide ` 26.3% water 35.1% sodium tripolyphosphate , 1.0% defoamer plug ` 2.6% chlorine plug : 100 . 0%
:"
The defoamer plug was prepared by heating together ~ 60 parts of a viscous (at room temperature) polyoxyalylene `~ glycol and 40 parts of a solid mixture of mono-and di~alkyl phosphate esters until the phosphate esters melted and then ;~

mixing until the mixture was uniform. The solution was then -'~:
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poured into a cylindrical mold and allowed to cool and form a solid plug at room temperature.
Similar plugs were produced following essentially the same procedure using: 50 parts of a polyethylene glycol, 25 parts of a polyoxyalkylene glycol, and 25 parts of a mixutre of mono-and di-alkyl phosphate esters~

A solid cast detergent was produced using the same ~ -~
formula and procedure as described in Example 2 except that the 1 part of defoamer was added as a plug similar to those described in Example 6.-Approximately 6 pounds of a solid cast detergent of this invention were prepared using the following procedure.
40 parts of anhydrous sodium metasilicate and 39 parts of a 10 weight percent aqueous solution of sodium hypochlorite were added to a laboratory mixer provided with a stirring means and a heating means. The solution was heated to approximately 55-60C. Twenty parts of anhydrous sodium tripolyphosphate were added to the solution and the solution mixed without heating until it began to thicken. After the mixture had thickened but while it was still pourable it was poured into a mold consisting of the dimensions described in Example 1.
Before the mixture completely solidified, 1 part of a defoamer plug similar to those described in Example 6 was added following he previously described procedure.

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The composition of the solidified cast detergent was approximately:

40% sodium metasilicate 35% water 20% sodium tripolyphosphate

4% sodium hypochlorite 1% defoamer plug 100%

This example was designed to illustrate that the sodium tripolyphosphate component of the previous examples can be formed in-situ by reacting sodium trimetaphosphate with sodium hydroxide via the following reaction , P03Na~P03Na-P03Na+NaOH >
Hopo3Na-po3Na-po3Na2+NaoH - > :
Naopo3Na-po3Na-po3Na2 Approximately 2200 ml of 50% aqueous sodium hydroxide was added to a stainless steel, jacketed beaker equipped with a Lightning stirrer. Following the addition the temperature was 70F. t2~1C.). Next 1440 g of powdered trimetaphosphate was added slowly. As the temperature o~ the mixture approached 100F. (38C.), cooling was applied. The remainder of the trimetaphosphate was added incrementally until the entire 1440 grams had been added. During the addition a maximum temperature of 200F. t93C.) was reached.
Upon sitting for several minutes the mixture formed a solid which could have been cast into a mold and used as the solid, cast detergent of this invention.

~%~z~ t This example illustrates that chlorinated trisodium phosphate may be used as the chlorine source. A solid cast detergent having the following composition was prepared:

36.0% caustic soda 27.0% water 36.0% sodium tripolyphosphate 1.0% defoamer 100 . 050 ; The above mixture was prepared using the procedure as described for Example 2. The mixture was poured (about 2360 g) into the mold which had a removable 2 inch diameter cylinder placed in the center. After the mixture had solidi-fied, the 2 inch diameter cylinder was removed leaving a hollow cylindrical cavity. This hollow cavity was filled with about 3~0 grams of molten chlorinated trisodium phosphate.
The chlorinated trisodium phosphate solidified upon cooling below its melting point. Some reaction occurred at the interface of the plug. It is believed that this reaction may be reduced significantly allowing the cast detergent to cool thoroughly before the chlorinated trisodium phosphate was poured and/or coating the cavity surface with an inert barrier such as, for example, parafin wax or mixed mono and dialkyl esters of polyphosphoric acid or like materials.

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EXhL`~PLE 1 0 This example was designod to i llustrato the produc'cion of a no~.-phosphate solid, cast detorgent. Fort~ parts OI 50u aqueous sodium hydroxide was hea~ed to 150F. (65.5C)in a jacketed stainl~ss st~el ~eaker equipped wi'ch a stirr2r. - ~onty par~s o~
anhydrOu5 sodium hydro~side were added and the mi~ture was stirred until a molten solu~ion was formed. I'~enty-five parts of liquid silicate ~RU silicate from Philadelphia Quartz~ having an SiO2/Na2O ratio of 2.54 was added and resulted in the temp~rature of the mix~ure increasing to about 200F. (93C. ) . The mixture was cooled to about 150~F. ~71C.) and 15 parts o sodium poly-acrylate were added slowly while stirxing continued.
The mixture was poured into a plastic contain~r where it solidified upon cooling. .

EXA~IPLE 11 The purpos~ Of thîs example is to compare the c~n-sistency of ~vailable chlorine recovery from a cast detergent-containing ar~icle produced according to the instant invention and a conventional, priox art, powder~d detergent. The prior axt fonmula used consisted of a mlxture of sodium tripolyphosphate, ~odium dichloxoisocyanurate (a chlori~e souxce~, sodium m~ta-silicate, and sodium hydroxidè. Sodium dichloroiso~yanurat~ :
csmorised approxirtlately 2 . 8% of the formula. The cast detergent-containing article used was produced by the process and using -the formula described in Example 5. The chlorine sourc:e ~as present in the fonn ol a ~plug sltu~tea approximately in the center ~:

%56~

of the cast base detergent. The cast detergent containing article was dispensed from an apparatus similar to the one illustrated ln FIGURE 4. The prior art formula was dis-pensed from a water-in-reservoir dispenser of the type illustrated in Figure 1 of U.S. Patent No. 3,680,070, issued July 25, 1972 (Nystuen).
Samples of the effluent from the dispensers were collected periodically and titrated for alkalinity to the phenolphthalein end point with hydrochloric acid and titrated for avialable chlorine with sodium thiosulfate using the conventional iodometric titration. The influent water temp-erature to both dispensers was about 71C. (160F.).
The amount of detergent present in the effluent was determined by the alkalinity of the effluent. The "chlorine recovered-percent of theoretical" (CRPT) was then calculated from the formula:

., CRPT available chlorine in effluent _ X 100 available chlorlne expeated in effluent (from detergent present) The results are illustrated in Figure 5. Figure 5 shows that the solid cast detergent of this invention provides very uniform chlorine recovery when compared to a prior art formu-lation. It is theorized that the differential solubility of the components of the prior art powdered detergent is responsible for the more erratic chlorine recovery shown by the prior art detergent.
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This example was designed to determine the effect of segregation during the manufacture of a conventional, prior art, powdered detergent. Since there should be no segregation with the solid cast detergent of this invention, (since all the components are physically locked in place~
any significant segregation with a powdered detergent would represent a disadvantage of the powdered detergent.
The conventional powdered detergent used was the same as that described in Example 11. This powdered deter-gent is commonly packaged in two-pound packages. Seven two-pound packages from the same production batch were selected at random for analysis. Ideally each of the packages should contain the same percentage of each of the four ingredlents.
The contents of each of the packages were weighed and the entire contents dissolved in an appropriate quantity of water in a 30 gallon drum to give a 1% weight/volume solution. This elim.inated any variation due to the possi-bility of different amounts of detergent being present in different packages. A 100 ml sample was withdrawn from each drum and titrated for available chlorine with sodium thio-sulfate using the standard iodometric titration. The results were as follows:

Sample No.Percent Available Chlorine 1 1.63 2 2.00 3 1.53 4 1.56 1.54 6 1.96 7 1.65 æ~

As indicated, the percentage of available chlorine varied from 1.53 to 2.00. This variation is in part due to segregation during mixing and packaging of the powdered detergent. This segregation is probably one factor leading to the variation in chlorine delivery illustrated in ~igure 5.

This example was designed to compare the chlorine , stability of cast detergents of this invention containing a chlorine source directly in the base detergent with cast detergents of this invention which incorporate a chlorine source as a core or plug, such as those described in Example 3. Three different chlorine sources were used: sodium dich-loroisocyanurate dihydrate (NaDCC-2H2O), lithium hypochlorite (LiOCl~, and calcium hypochlorite (Ca(OCl)2). All of the compositions were produced following the procedure of Example 1 with the chlorine source being added directly to the mix-ture following the addition of the sodium tripolyphosphate in one case and the chlorine being added as a plug in the other.
In the third case the chlorine source plug was dipped in a parafin wax (m.p. 52.5 F.) and in a fourth case the chlorine source plug was dipped in mono and dialkyl ester of polyphos-phoric acid, a wax-like solid (m.p. 150-160 F.). The formula used and the available chlorine remaining after various storage times at room temperature are shown in Table I.
As indicated by Table I, when the chlorine source is added directly as a component of the cast detergent most of the chlorine is lost within 24 hours. However, when the chlorine source is added directly as a component of the cast detergent most of the chlorine is ost within 24 hours.

~Si62~

However, when the chlorine source is incorporated into the cast detergent as a preformed core or plug, excellent chlorine stability results with Ca(OCl)2 and lithium hypochlorite but not with NaDCC-2H20. When the chlorine source plug was coated with a film of parafin wax or a waxy mono and dialkyl ester of polyphosphoric acid the best stabilities were obtained.

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The purpose of -this example was to compare the uni-formity of delivery of defoamer from: (A) a conventional powdered detergent (Score,TM a commercial product of Economics Laboratory, Inc.); (B) a cast detergent (product of Example 5); and (C) a cast detergent incorporating the defoamer as a core or plug (product of Example 6). All three of the formu-lations contained 1% by weight of defoamer. The (A) conven-tional detergent and (B) the product of Example 5 contained the same defoamer; (C) the product of Example 6 contai~ed the blend of two defoamers described in Example 6 (the blend was used to obtain a solid product which could be molded into a plug).
All tests were conducted in a Hobart C-44 (trademark) single tank dishwashing machine. A C-ll Dispenser (trademark of Economics Laboratory, Inc.), a water-in-reservoir type dispenser, was used to dispense product (A) (the conventional powdered detergent). The Hobart C-44 (trademark) machine was equipped with a dispenser similar to that illustrated in Figure 4 for dispensing the solid cast detergent products (B) (product of Example 5) and (C) (product of Example 6). Both dispensers were controlled by a conductivity base controller of the type described in U.S. Patent No. 3,680,070, issued :`
July 25, 1972 (Nystuen). The controller was set to maintain a 0.2% concentration of detergent in the wash tank. The water temperature was about 140F. (65C.) for all of the tests.
Defoamers are included in detergents for spray-wash machines to control foam created by food soils. Foam in a wash . . ' .
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tank leads to entrapment of air in the wash solucion being recirculated through the machine and results in a reduction in mass and kinetie energy and which leads to poor soil removal.
Excess .o~ in a wash tank causes a loss in water pressure which can be measured by,a manometer connectodto the wash manifold up stxea~ fxom the water pump. Egg is a common roam-causing food soil and was selec~ed for use in this test.
The C-ll Dispenser optimally holds about four pounds of powdered detergent ~nd thus foux pounds o~ conventional detergen~ (A) were used in the test. Products ~B~ and (C~ were approximately six pounds each and were of the conigu~ation described .in Exc~ple 1 and illustrated in Figures 1-~.
The pressure ~in inches o~ water) was recorded when the dispPnser ~as freshly charged, when ibout one-~alf of the detergent had been dispensed, and when about four-fifths of the detergen~ had been dispen~ed~ Manometer readin~s wexe taken on the freshly'charged detergent~ with water alone, '~2) af~er the d~3tergen~was ad~ed, ~3) f~ve minut.es after 115 grams of eg~
were added, and t4) ive minutes after an addi~ional 100 gxams of egg were added.
Between the"Freshly Charged" test and the "Detergent 1/2 Spent" test~ the ill val~a was opened to deliver 2 gallons of water per minute fox dilution to simulate norrnal dilution of the wash tank by rinse water which is diverted to the wa~ tank to freshen the wash water. The conducti~7it~ controller dispensed de~ergen~ as required ~o maintain a O . 2% concentration o:~ deterg~n~

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in tile was~. t~n~ . r~hen about one-half of the ~eter~ent or.iginally in the disl~ensers was left, ~anom~ter rea~ings were t~en and the t~lo egq additions described above repeated with readings beins tc~en five mi~ut~s after each addition. The same ~rocedure was repeated a~ter about one-rifth o~ the detergent ori~inally present was lef~ in the dispensers tfour-fifths spent)~
The "Detergent 1/2 Spent" test was somewhat more se~exe than the "~reshly Charged" test and, liXewise, the "Detergent 4/5 Spent" test was somPwhat more severe than- the "Deter~ent lf2 Spent" test, due to the cummulative concentration of e~g soil resulting because the wa~h tank was not drained between tests.
~ he results of these tests are sL~mari~ed in Table II.
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i2~ ( The data in Table II indicates tnat Product (C) ( the ~-oduc~ oF ~::a~nple 6 with the defoam2r included a~ a plug) had t~.e highest an~ most consistent wash pressures and that Product (3) (the product of Example 5 with the defoamer incIudPd in th~
cast detergent~ had higher and more consistent wash pressures than Product ~A) (the conventional pGwdered detergent). The higher and more consistent wash pressures indicate more uniform deroamer delivery.
It was noted ~hat the defoamer incorporated in the pow dered detergent ~A) floatedto the top and ~ormed an oily film in the water-in-reservoir dispenser. It is believed that this rssulted in slug-feedlng o~ the defoamer ins~ead of uni~orm i delivery. In contrast, with ~he solid cast detergentof this inven-t;on, both the detergent and defoamer are dispensed simultaneously which helps æ sure uniform dispensins of the ds~oamer.

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Claims (21)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A detergent-containing article of commerce comprising:
(a) a three-dimensional, solid cast detergent composition containing at least two solid components; at least one of said solid components comprising an alkaline hydratable chemical and another said solid component comprising a hardness-sequestering agent;
(b) water of hydration associated with said alkaline hydratable-chemical or said sequestering agent; and (c) a receptacle-shaped mold surrounding and in contact with said solid cast detergent composition on all but one surface thereof.

2. The article of claim 1 wherein said mold is the mold in which said composition was cast and solidified.

3. The article of claim 2 wherein said hydratable chemical comprises at least 30% of said composition.

4. The article of claim 2 wherein said article further comprises a cover attached to the said receptacle-shaped mold.

5. The article of claim 2 wherein said article further comprises at least one preformed core, said core being surrounded by and in contact with said detergent composition on at least one side of said core.

6. The article of claim 5 wherein said preformed core comprises a source of available chlorine.

7. The article of claim 5 wherein said preformed core comprises a defoamer.

8. The article of claim 5 wherein said article comprises at least two preformed cores, at least one of said cores comprising a source of available chlorine and at least one of said other at least two cores comprising a defoamer.

9. The article of claim 5 wherein the said preformed core is separated from the said detergent composition by an inert barrier film.

- 38a -

10. A method for using the detergent composition of the detergent-containing article of Claim 1 comprising:
a. placing said detergent-containing article in a detergent dispensing device for dispensing detergent into the article-washing zone of an article washing apparatus, whereby only the said side of the solid cast detergent composition not surrounded by said receptacle-shaped mold is exposed to the interior of said detergent dispensing device, thereby providing said detergent dispensing device with essentially one unsurrounded, exposed surface of detergent composition;
b. impinging a flow of aqueous liquid upon said unsurrounded, exposed surface to form an. aqueous liquid detergent containing said detergent com-position in the aqueous liquid; and c. dispensing said aqueous liquid detergent into said article-washing zone for the purpose of washing articles therein.

11. A process for forming a three-dimensional, solid cast detergent within a receptacle-shaped mold having side molding surfaces, said process comprising the following steps:
a. heating about 50-75 parts by weight of a 50-75 weight percent aqueous solution of an alkali metal hydroxide to about 55° to 65°C.;

b. distributing about 30 to 40 parts by weight of an alkaline hydratable chemical in said solution;
c. allowing said solution to begin to cool and thicken, and mixing said solution during said cooling and thickening;
d. pouring said thickened solution into said receptacle-shaped mold and filling said mold to a level at least part way up said side molding surfaces, the upper surface of the thus-poured, thickened solution being unsupported by said receptacle-shaped mold; and e. allowing said solution to solidify in said mold, whereby a solidified surface if the solidified cast detergent is the said upper surface unsupported by said mold.

12. The process of claim 11 wherein said alkali metal hydroxide is sodium hydroxide.

13. The process of claim 12 wherein said alkaline hydratable chemical is added as sodium tripolyphosphate.

14. The process of claim 11 further comprising, follow-ing step (d) and prior to step (e), the step of inserting in said thickened solution in said mold at least one preformed plug composition.

15. The process of claim 14 wherein at least one of said at least one plug composition comprises a source of available chlorine.

16. The process of claim 14 wherein at least one of said at least one plug composition comprises a defoamer.

17. The process of Claim 11 wherein the said hydratable material is selected from the group consisting of sodium or potassium phosphate.

18. The process of Claim 11 wherein the said hydratable material is added as sodium pholyphosphate.

19. The process of Claim 11 wherein the said hydratable material added is selected from the group consist ing of sodium or potassium trimetaphosphate.

20. The process of Claim 11 wherein the product contains at least one polyelectrolyte water conditioning material.

21. A solid, cast detergent-containing article produced by the process of Claim 11 comprising:
a. said solid cast detergent, and, surrounding and in contact with all but the said upper surface of said solid cast detergent, b. the said mold into which said solid cast deter-gent was cast, said mold acting as a container for said detergent.