Stratified solid cast detergent compositions and methods of making same

Stratified solid cast alkaline detergent compositions are disclosed in which the concentrations of an active alkalinity source and water of hydration which contain at least one granular material in varying concentration throughout the composition. Methods of making and using the disclosed compositions are also disclosed.

FIELD OF THE INVENTION 
The present invention relates to detergent compositions, and methods of 
making them, that are useful for warewashing (i.e., washing of tableware, 
cutlery, etc.), particularly in large-scale commercial food service 
operations. 
BACKGROUND OF THE INVENTION 
Traditionally, food service equipment, tableware, serving utensils and 
other reusable food service items have been cleaned with solutions of 
alkaline detergents in a spray washing type machine, typically a dish 
washing machine or a pan washing machine. The cleaning operation is fairly 
straightforward and requires adequate water temperature and pressure, in 
combination with alkaline builders and other detergent ingredients to 
effectively emulsify the greases and oils and loosen and suspend the soils 
that are present and to allow them to be freely rinsed away from the 
tableware with a final rinse. 
Presently available solid cast alkaline detergent compositions provide a 
uniform formulation throughout the life of the product (see for example 
those disclosed in U.S. Pat. Nos. RE32,818 and 32,763). However, providing 
a constant concentration of all formulation components can provide 
significant disadvantages. 
Aside from mechanical operating conditions and limitations, including 
temperature, the greatest detriment to proper adequate cleaning and bright 
clean, spot-free, film-free results on the tableware has been water 
hardness. Other aspects of cleaning such as soil load, etc., are usually 
handled by increasing or varying the balance of alkaline components within 
the basic formulation. The results gained are not appreciably different 
with any alkaline component, be it an alkali metal hydroxide, an alkaline 
silicate or, for that matter in many cases, an alkaline phosphate or 
carbonate. The detrimental effects of hard water are handled in 
institutional and commercial warewashing and spray washing operations by 
either putting a water conditioning system in place before the cleaning 
operation or formulating the product to contain high levels of water 
conditioning agents. The most effective of these water conditioning agents 
are the complex phosphates which offer the benefits of synergistic 
enhancement of hard surface detergency and water softening. 
However, the use of constant and sustained high levels of phosphates has 
significant disadvantages. For example, (1) high phosphate concentrations 
have a negative environmental impact; (2) high levels of complex 
phosphates are expensive components of a detergent formulation; and (3) 
the high level of phosphate required to effectively control or eliminate a 
lime/scale buildup are often high enough to unbalance the formula away 
from the effective cleaning material (i.e., the alkaline builder) toward 
the low alkalinity complex phosphate which is being used to control water 
hardness. 
In practice, a commercial or institutional warewashing operation using hard 
water must periodically descale their washing machines with an acidic 
compound, which dissolves the lime/scale and restores the machine to its 
original bright finish. All acidic descalers have a corrosive effect on 
machine parts and/or plumbing. Unfortunately, this method does not 
eliminate film and buildup which may occur on the actual tableware and be 
highly noticeable on glass and crystal. To enhance results and offer film 
removal and reduced streaking on these types or surface, it is not unusual 
to use extremely high detergent concentrations to over condition the water 
or to use acidic or conditioning rinse aids which are substantially more 
costly than the ordinary sheeting agents used to accelerate the drying of 
tableware in machine washing operations. Furthermore, the washing 
equipment must be shut down during the deliming/descaling process, 
resulting in a loss of productive washing time. 
It would, therefore, be desirable to provide a warewashing detergent 
composition that provided adequate detergency while also removing lime and 
scale from the washing equipment in which it is used. It would also be 
desirable to provides such a composition that would provide these 
deliming/descaling benefits without the need to shut down the washing 
equipment for the cleaning operation. 
In many washing applications it may also be advantageous to provide varying 
degrees of active agents throughout the life of a detergent product. For 
example, it may be desirable to provide extra cleaning power at the end of 
product life before the detergent composition is changed in order to 
assure that alkalinity concentration is not depressed during the 
changeover process. It would therefore be desirable to provide detergent 
compositions which provided a heightened level of alkalinity as the 
product was used. 
It may also be advantageous to periodically provide a strong dose of 
formulation components to provide other benefits. For example, use of high 
concentrations of silicates have been demonstrated to replenish glaze on 
the surface of china and other glazed table ware. It would therefore be 
desirable to provide detergent compositions in which the concentration of 
silicate is periodically increased to provide this replenishing effect. 
It may also be advantageous to reduce the conductivity of the detergent 
solution produced by use of a solid cast alkaline detergent composition. 
Reducing the conductivity of late in the product life would cause the 
washing machine to increase the rate of dissolving the detergent 
composition, resulting in a higher concentration of active ingredient in 
the machine washing solution. It would therefore be desirable to provide a 
solid cast detergent product which would provide this type of variation in 
conductivity. 
These and other advantages are provided by the present invention. 
SUMMARY OF THE INVENTION 
The present invention provides solid cast alkaline detergent compositions 
which are stratified (i.e., nonuniform) and provide a reproducible varying 
concentration of certain formulation components throughout the 
composition. In use, these detergent compositions provide an increasing or 
decreasing concentration of one or more formulation components as tile 
product is used. 
Stratification of the detergent compositions is achieved by providing the 
formulation components to be stratified in granular (i.e. larger than 
about 100 mesh) form. The granular component or components are added to a 
molten detergent suspension comprising an active alkalinity source and 
water of hydration, in addition to other formulation components typically 
found in this type of composition, while maintaining the temperature of 
the suspension at a level sufficient to provide low viscosity. Because of 
its granular nature, the granular material will not completely dissolve in 
the saturated detergent composition and, because of its density relative 
to the suspension, will stratify to produce a variation in concentration 
from the top to the bottom of the composition. 
Any material suitable for use in a solid cast alkaline detergent 
composition available in a granular form can be stratified in accordance 
with the present invention. In preferred embodiments, sodium 
tripolyphosphate (STPP), caustic, metasilicate, and sodium carbonate are 
stratified. More than one formulation component can be stratified, such as 
both STPP and caustic. Components may also be stratified in opposite 
orientations of the varied concentration gradient. For example, STPP may 
be stratified from top to bottom of a composition in increasing 
concentration, while caustic is stratified from bottom to top in 
increasing concentration. 
In certain preferred embodiments, the solid cast detergent compositions of 
the present invention allow for the automatic, periodic deliming or 
descaling of both the washing machine and the tableware being washed 
therein. The solid cast alkaline detergent compositions of the invention 
are non-uniform in composition and provide an increasing concentration of 
water conditioning material as the composition is consumed. Thus, as the 
composition is used, the amount of water conditioning increases to the 
point where the concentration of conditioning materials is sufficient to 
delime/descale the washing machine while the composition is in use. 
Any granular water conditioning material can be used in practicing the 
present invention, although complex phosphate materials are preferred. 
Suitable phosphate materials include, sodium tripolyphosphate (STPP), 
tetrasodium pyrophosphate (TSPP), sodium hexametaphosphate (SHMP), and 
sodium trimetaphosphate (STMP), along with their other alkali metal 
analogs, particularly potassium analogs (such as, for example, potassium 
tripolyphosphate). STPP is particularly preferred and can be used in any 
of its commercially available granular forms. Dense granular STPP in its 
coarsest commercially available forms is particularly preferred. 
In certain preferred embodiments, the composition is cast within a jar or 
similar type disposable container (such as that shown in FIGS. 1 and 2). 
In such embodiments, the composition is manufactured such that there is a 
higher concentration of water conditioning material at the bottom of the 
container than at its top. The container is typically inverted during use, 
such that the opening in the top of the container is placed over a 
controlled spray stream of water (as shown in FIG. 3). The water spray 
impinges on the surface of the detergent composition, dissolving the solid 
to form a detergent solution. The detergent solution then flows into the 
wash tank of the machine. The initially dissolved solid contains a 
significantly smaller amount of water conditioning material than the 
bottom of the container, which will be the last part dissolved from the 
inverted container as the stream of water continues to dissolve the 
composition. 
The water conditioner (such as for example, phosphate and/or other suitable 
materials) level throughout the jar preferably should be adequate to 
maintain balanced detergency and threshold water conditioning effect even 
where minimal conditioner concentrations are present. As the product is 
consumed, the conditioner concentration preferably increases so that 
during the consumption of the last about 20-25 percent of the container 
the concentration of conditioner is sufficient to not only condition the 
water but also to purge, clean and actually descale and delime both the 
machine and the tableware being washed. The phosphate concentration in the 
last portions of the composition is preferably high enough to, in most 
cases, completely eliminate or at the very least significantly reduce any 
film or scale buildup which may have occurred during the usage of the 
early part of the composition. The end result is to provide an effective 
product, minimizing raw material costs and adding the regular, periodic 
extra phosphate level needed to eliminate any detrimental effects of high 
water hardness levels without descaling. 
Methods are also disclosed for making the compositions of the present 
invention. The stratification of phosphate content within the compositions 
is produced by controlling the viscosity of the molten detergent 
suspension which hardens into the solid cast detergent composition such 
that the phosphate components can stratify as the composition is cooled. 
Temperature control is the most important factor in producing the desired 
stratified effect, although other means for controlling viscosity and the 
stratification effect can also be used. Physical form, granulation and 
density of the formulation components can also have significant effects of 
the stratification of the resulting product. 
In certain preferred embodiments, formulation components, including water 
and an active alkalinity source (such as an alkali metal hydroxide), are 
mixed. The temperature of the mixture is then adjusted to provide the 
desired viscosity of the molten detergent suspension. The granular 
material to be stratified is then added to the suspension. The appropriate 
viscosity is that which will provide the desired degree of stratification 
for a specific composition upon cooling. The molten suspension is then 
allowed to cool and solidify in a useable form (such as, for example, a 
cast block in a disposable jar). 
Although formulation components can be mixed is any suitable order, 
typically the component to be stratified is added in its granular form as 
the last component to the molten detergent suspension. This allows greater 
maintenance of the granular form of the material, reducing dissolution of 
the material into the suspension. Dissolution of the granular material 
will, in most instances, result in reduction or elimination of the 
stratification of the granular material. 
In certain preferred embodiments, the molten detergent suspension is also 
rapidly cooled in order to reduce or minimize degradation of the water 
conditioning material (such as for example, reversion of complex 
phosphates) to form degradation products (such as for example, 
orthophosphate). Reducing degradation of the water conditioning material 
maintains the water conditioning activity of the compositions. 
In composition incorporating complex phosphate as the water conditioning 
material, it is preferred to prevent a substantial level of orthophosphate 
from forming the composition. Preferably less than 40% of the complex 
phosphate is allowed to revert. In certain particularly preferred 
embodiments the level of reversion is reduced to less than 20% and even 
less than 10% however, where the degradation product is orthophosphate, 
the composition may contain an average composition throughout of less than 
about 50% orthophosphate as a result of reversion of the complex 
phosphate. 
Stratification of components other than STPP can also be accomplished in 
accordance with the present invention. Active alkalinity content can also 
be varied throughout a product such that more active alkalinity is 
provided in the initial stages of use of the composition. For example, in 
certain preferred embodiments which are cast in jars, the active 
alkalinity content is higher at the top of the jar (the portion used 
first) than at the bottom (the portion used last). This variation in 
active alkalinity content provides many advantages including more 
aggressive cleaning action at lower concentrations at the start of product 
use and deliming, defilming and reconditioning at the end of product use.. 
Variation of active alkalinity can be achieved when a variety of active 
alkalinity sources are used, including alkali metal hydroxides (such as 
for example sodium hydroxide and potassium hydroxide), silicates (such as 
for example alkali metal metasilicates), carbonates (such as for example 
alkali metal carbonates) and simple phosphates (such as for example 
orthophosphate). In addition, higher active alkalinity levels can be 
achieved at the end of the jar by stratifying the active alkalinity source 
(such as for example an alkali metal hydroxide or an alkali metal 
silicate) in granular form instead of or in addition to the 
water-conditioning material. 
Although any desired level of active alkalinity can be used in compositions 
of the present invention, preferably the compositions contain about 5% to 
about 65%, more preferably about 10% to about 50%, average active 
alkalinity by weight. Both higher alkalinity compositions (such as those 
containing about 25% to about 50%) and lower alkalinity compositions (such 
as those containing about 5% to about 25%) may be made in accordance with 
the present invention. 
Compositions of the present invention can also be designed to provide a 
variation in the conductivity of the washing solution circulated in a 
machine during use. For example, providing an increased concentration of 
STPP or decreased concentration NaOH at the end of product life will 
reduce the conductivity of the solution of dissolved detergent in the 
machine, resulting in an increased rate of dissolution. This increased 
dissolution will automatically result in an increased concentration of the 
composition being dispensed without adjustment of the concentration 
(conductivity) control, enhancing the composition's benefits with higher 
concentration.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Compositions of the present invention are non-uniform, cast solid alkaline 
detergent manufactured by heating an aqueous suspension primarily of water 
and alkaline hydratable materials (such as alkali metal hydroxides, 
carbonate, silicates and phosphates) together with organic additives of 
value in a detergent composition (such as surfactants, chelates, organic 
water conditioning materials, defoamers and a chlorine releasing compound 
(e.g.,an inorganic hypochlorite or an organic chlorine source)). The 
components are mixed and temperature adjusted to be just high enough to 
reduce the viscosity of the suspension to a point where the controlled 
stratification desired will occur. STPP, the active alkalinity source or 
other component to be stratified is preferably added last to reduce 
chemical (such as for example reversion) or physical (such as for example 
dissolving) degradation which may occur. This temperature will vary based 
upon the components, their percentage in the product, physical form and 
density which may be tailored for the optimum desired effect for the 
product application. Preferably, the temperature is adjusted to from about 
130.degree. F. to about 195.degree. F., preferably from about 148.degree. 
F. to about 163.degree. F., or about 135.degree. F. to about 168.degree. 
F. most preferably from about 153.degree. F. to about 158.degree. F. Below 
148.degree. F. it may become more difficult to achieve repetitively 
uniform stratification. Below this temperature some formulations may be 
more viscous or tend to entrain air resulting in a lower fill weight, 
which may be desirable under some circumstances. However, the product will 
still be stratified below this temperature. Temperatures above 163.degree. 
F. are higher than needed to maintain the reduced viscosity of many 
formulations. However, these higher temperatures may be required in 
certain formulations (such as those containing EDTA, carbonate or low 
density STPP in amounts more than about 10%) to maintain lower viscosity 
and higher fluidity of the molten detergent suspension during mixing. 
Prolonged exposure to these higher temperature may also result in 
deterioration or degradation of some formulation components. 
In preferred embodiments, the compositions of the invention are essentially 
non-uniform (stratified) hydrated alkaline materials which have been cast 
in the container in which they are meant to be sold, transported and 
dispensed. The materials are designed to stratify upon standing and 
solidify as a non-uniform cast solid material. By incorporating components 
of selected particle size, shape, surface area, density and hydration 
characteristics, it is possible to create, on a repetitive basis, this 
unique solid cast composition with highly desirable characteristics. In 
preferred manufacturing processes the viscosity of the molten detergent 
material to be reduced to the point where the later sequential addition of 
some of the components lead to rapid stratification within the container. 
In the case of complex phosphates, in one preferred embodiment high 
density granular sodium tripolyphosphate is added as one of the last 
components to the composition once the molten detergent suspension has 
reached a relatively low viscosity after the other components have been 
added. Earlier additions may include other phosphate materials which are 
not necessarily designed to become part of the highly stratifying 
component. 
The reduction in viscosity of the detergent suspension may be accomplished 
by any method known to those skilled in the art. Such methods include 
without limitation (1) adjusting the temperature of the suspension to the 
point that the material becomes readily flowable, (2) adding dispersing 
materials (such as lignosulfonates and certain surfactants or organic 
compounds) which have a viscosity reducing effect, and (3) varying 
particle size or physical form of formulation components. Controlling 
temperature is the preferred method of producing the desired viscosity. 
Since higher complex phosphate is subject to reversion to pyro- or 
orthophosphate in a fluid, aqueous, highly alkaline environment at 
elevated temperatures, it is also important in certain embodiments to add 
last and quickly cool the molten detergent suspension to a temperature at 
which it will solidify at a sufficiently rapid rate to reduce or prevent 
reversion, yet at which the desired stratification process will occur. 
Appropriate temperature ranges for providing stratification and reducing 
reversion will be dictated by the nature of the components and the 
relative amounts in which they are found in any given composition. For a 
given composition formulation, an appropriate temperature, if necessary, 
can be determined by trial and error; the formulation can be mixed, 
maintained at various temperatures, cooled and then examined to determine 
whether the degree of stratification and reversion is within the desired 
parameters. Temperatures of from about 135.degree. F. to about 168.degree. 
F. have been found to produce stratification without significant reversion 
in typical formulations. Temperatures of from about 148.degree. F. to 
about 163.degree. F. provide particularly desirable results. Temperatures 
above about 170.degree. F. have been found to produce significant 
reversion in many formulations; however, such temperatures can be used for 
a particular formulation if the desired stratification and reduced 
reversion characteristics are produced. Extended mixing time at elevated 
temperatures can increase component degradation. In compositions having 
lower active alkalinity content (such as for example, those containing 
about 5% to about 25% average active alkalinity), the temperature range 
useful for providing the desired stratification effect may be lowered, 
even to as low as about 115.degree. F. 
The compositions of the present invention can include any of the components 
typically found in alkaline warewashing compositions. For example, any 
source of active alkalinity can be used to provide the desired alkalinity 
to the compositions. The alkali component of appropriate formulations is 
typically provided by an alkali metal hydroxide, such as sodium or 
potassium hydroxide. The alkali metal hydroxide can be used in any 
available liquid or solid form, although solid form is preferred. If solid 
metal hydroxide is used, any particle size can be used; however, 
commercially available beads (pellets) of medium size have been found to 
provide desirable results. Particularly, dissolving of metal hydroxide 
pellets is an exothermic process which can be harnessed to elevate the 
temperature of the resulting molten detergent suspension. Adjusting the 
particle size of the metal hydroxide may also contribute to adjustment of 
the viscosity of the molten detergent suspension. 0.75 mm sodium hydroxide 
pellets (bulk density 1,150 kg/m.sup.3 or about 73 lb./ft.sup.3) have been 
found to provide desirable results. Alkali metal silicates, such as 
anhydrous sodium metasilicate, can also be used as an active alkalinity 
source to replace some or all of the metal hydroxide. In larger bead or 
granular form, sodium hydroxide and/or alkaline silicate (such as for 
example anhydrous metasilicate) may be used as stratified components. 
The compositions can also contain a source of available halogen. Any 
organic or inorganic material which provides active halogen, particularly 
chlorine (such as in the form of hypochlorite or Cl.sub.2), can be used. 
Examples of appropriate chlorine sources include alkali metal and alkali 
earth metal hypochlorite, hypochlorite addition products, chloramines, 
chlorimines, chloramides, and chlorimides. Compounds of this type include 
sodium hypochlorite, potassium hypochlorite, monobasic calcium 
hypochlorite, dibasic magnesium hypochlorite, chlorinated trisodium 
phosphate dodecahydrate, potassium dichloroisocyanurate, trichlorocyanuric 
acid, sodium dichloroisocyanurate, sodium dichloroisocyanurate dihydrate, 
1,3-dichloro-5, 5-dimethylhydantoin, N-chlorosulfamide, Chloramine T, 
Dichloramine T, Chloramine B and Dichloramine B. Stability is maximized 
when these materials are used in granular form and added last before the 
component(s) to be stratified. Encapsulated chlorine sources may also be 
used to provide better in-processing and storage stability. 
The compositions may also contain surfactants, including nonionic 
surfactants, anionic surfactants, amphoteric surfactants and cationic 
surfactants. Preferred materials for machine spray washing application are 
those nonionic surfactants with defoaming characteristics (such as those 
sold under the "Triton CF" series by Union Carbide). Preferred surfactants 
include alkali metal alkyl benzene sulfonates, alkali metal alkyl 
sulfates, and mixtures thereof. Nonionic surfactants can also be used 
alone or in combination with anionic, amphoteric or cationic surfactants. 
Suitable nonionic surfactants include polyethylene condensates of alkyl 
phenols, products derived from the condensation of ethylene oxide with the 
reaction product of propylene oxide and ethylene diamine, the condensation 
product of aliphatic fatty alcohols with ethylene oxide as well as amine 
oxides and phosphine oxides. Products sold under the tradename "Pluronic" 
provide desirable results. 
The compositions of the present invention may contain a supplemental water 
conditioning agent to enhance performance by sequestering calcium and/or 
magnesium ions at lower phosphate levels or to replace phosphate where its 
presence is undesirable. These include organic chelating/sequestering 
agents (such as gluconates, citrates, glucoheptanates, phosphonates, EDTA, 
nitrilo triacetate (NTA), polyacrylic acid of molecular weight of about 
1,000-4,000 or greater in the useful range of sequestrants alone with 
copolymers and blends of the acrylic/maleic or other forms. These 
materials may be incorporated at any useful level from less than 1% to 
more than 15%. In addition, the compositions of the invention may contain 
any functional defoamer which may or may not have surface active 
properties. 
The compositions of the invention can be made by combining the components 
of the formulation in suitable mixing equipment. Preferably, any source of 
complex phosphate is added last to reduce the time in which the material 
is exposed to elevated temperatures. As mixing occurs the temperature of 
the detergent suspension is adjusted to the desired range. In formulations 
employing solid metal hydroxide as an active alkalinity source, 
dissolution of the metal hydroxide is exothermic and generates heat, 
Minimal heat is required to be supplied from external sources. When liquid 
alkali metal hydroxide or other source of active alkalinity are used heat 
may need to be supplied. Heat may be applied by usual means, such as a 
steam-heated mixer jacket. The temperature of the detergent suspension may 
also be cooled, if necessary, to provide the desired temperature. Any 
known cooling means can be used, including a water-cooled mixer jacket. 
When the detergent suspension has reached the desired temperature, the 
molten suspension is poured into a mold (such as a disposable container) 
where it is allowed to cool. Formation of a stable hydrate by the water of 
hydralion in the alkali material causes the molten suspension to form a 
solidified mass. 
The following examples demonstrate certain preferred embodiments of the 
compositions and methods of the present invention. 
EXAMPLE 1 
300 g samples were prepared according to the following formulations: 
______________________________________ 
sample I II III IV 
______________________________________ 
water 26.3 (wt %) 
24.8 23.25 
21.7 
sodium hydroxide (solid) 
58.7 55.2 51.75 
48.3 
STPP (dense granular) 
15.0 20.0 25.0 30.0 
______________________________________ 
The samples were prepared by adding the required amount of water to a 
beaker, followed by the addition of bead (pelletized) sodium hydroxide 
with mixing. The hydration reaction of the sodium hydroxide was exothermic 
and the solution was continually mixed as the sodium hydroxide dissolved. 
The temperature was then adjusted to 150.degree. F. The required amount of 
dense granular sodium tripolyphosphate (density: 62 lb./ft.sup.3 ; 
particle size: &gt;95% on 100 mesh (U.S.) and &gt;75% on 0.5 mm (metric)) was 
then added quickly and mixed for approximately one minute. The temperature 
was then verified to be just below 150.degree.. The molten detergent 
suspension was then poured into an eight ounce straight sided cylindrical 
bottle with a thirty eight millimeter cap, the dimensions of the 
cylindrical portion of the bottle being approximately five and one quarter 
inches high by approximately two inches in diameter. The portion of the 
three hundred gram sample which was poured into the bottle and did not 
adhere to the beaker occupied approximately three and one half inches of 
vertical height of the bottle. The samples were then capped as they were 
made and immersed to a depth of approximately four and one half inches in 
a large sink of tap water at approximately 58.degree.. The samples 
solidified relatively quickly and were allowed to remain in the water to 
cool to room temperature. 
After approximately two hours, the physical appearance of the samples was 
observed in front of a bright light. Each sample showed marked 
stratification to the naked eye. The appearance of stratification was 
visibly noticeable based upon the fact that the top portion of the samples 
was extremely uniform and almost translucent while the lower portion of 
the stratified material showed the granular texture of the sodium 
tripolyphosphate being evident and opaque in appearance. This opaque area, 
which showed as a dark shadow in front of a bright light, appeared to 
represent the highly stratified portion of the sample. Its height in the 
container varied from a little over one inch for the sample containing 
fifteen percent sodium tripolyphosphate to nearly two inches for the 
sample containing thirty percent sodium tripolyphosphate. 
EXAMPLE 2 
Samples were prepared including sodium metasilicate and sodium carbonate 
according to the following formulations: 
______________________________________ 
A B C D E F 
______________________________________ 
water 23.25 (wt %) 
23.25 23.25 
23.25 
23.25 
23.25 
sodium hydroxide 
51.75 51.75 51.75 
51.75 
51.75 
51.75 
(bead) 
STPP 20.0 20.0 20.0 5.0 5.0 10.0 
(dense granular) 
anhydrous sodium 
5.0 -- -- -- -- -- 
metasilicate 
sodium carbonate 
-- 5.0 -- -- 5.0 15.0 
(light soda ash) 
sodium carbonate 
-- -- 5.0 -- -- -- 
(dense soda ash) 
sodium hydroxide 
-- -- -- 20.0 15.0 -- 
(bead) 
______________________________________ 
The components were mixed as described above, with the second listed 
portion of sodium hydroxide being added last. Samples A-E showed visible 
stratification. Stratification of sample F was not apparent to the naked 
eye, but a chemical analysis of the sample was not performed to determine 
the degree of stratification. 
EXAMPLE 3 
Samples were made incorporating organic water-conditioning materials 
according to the following formulations: 
______________________________________ 
A B C D E F G H 
______________________________________ 
water 23.25 23.25 23.25 
23.25 
23.25 
23.25 
23.25 
23.25 
sodium 51.75 51.75 51.75 
51.75 
51.75 
51.75 
51.75 
51.75 
hydroxide 
(bead) 
STPP 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 
(dense 
granular) 
polyacrylic 
5.0 -- -- -- -- -- -- -- 
acid 
(4500 MW) 
acrylic maleic 
-- 5.0 -- -- -- -- -- -- 
copolymer 
(SoKolan 
CP5) 
citric acid 
-- -- 5.0 -- -- -- -- -- 
gluconic -- -- -- 5.0 -- -- -- -- 
acid (50%) 
sodium -- -- -- -- 5.0 -- -- -- 
glucohep- 
tanate 
trisodium 
-- -- -- -- -- 5.0 -- -- 
nitrilo 
triacetate 
tetrasodium 
-- -- -- -- -- -- 5.0 -- 
EDTA 
phosphonate 
-- -- -- -- -- -- -- 5.0 
(Dequest 
2000) 
______________________________________ 
The inclusion of these additives did not appear to appreciably change the 
stratification characteristics on a visible basis seen in prior samples 
without the additives. 
EXAMPLE 4 
Samples were made including surfactants and defoamers to the following 
formulations: 
______________________________________ 
A B C D E F 
______________________________________ 
water 23.25 23.25 23.25 
23.25 
23.25 
23.25 
sodium hydroxide 
51.75 51.75 51.75 
51.75 
51.75 
51.75 
(bead) 
STPP (dense granular) 
20.0 20.0 20.0 20.0 20.0 20.0 
polyacrylic acid 
5.0 3.0 3.0 3.5 3.5 4.0 
(4500 MW) 
nonylphenol ethoxylate 
-- -- -- 1.5 -- -- 
(N-95) 
ethylene oxide- 
-- -- -- -- 1.5 -- 
propylene oxide 
(Pluronic L) 
modified aryl aloxylate 
-- -- -- -- -- 1.0 
(Triton CF) 
dodecyl benzene 
2.0 -- -- -- -- -- 
sulfonic acid 
(anionic) 
Miranol JEM -- 2.0 -- -- -- -- 
(amphoteric) 
BTC 2125M (quaternary 
-- -- 2.0 -- -- -- 
aryl) 
______________________________________ 
The inclusion of these additives did not visibly affect the observed 
stratification. 
EXAMPLE 6 
A production-sized batch (1000 lbs.) of the following formulation was made: 
______________________________________ 
NaOH (50% soln.) 427 lbs. 
sodium carbonate 30 
(light soda ash) 
polyacrylic acid 60 
(MW 4500) 
NaOH (solid) 260 
Triton CF76 8 
antifoam 1.5 
sodium glucoheptanate 15 
STPP (dense granular) 200 
______________________________________ 
The batch was made according to the general steps described in Example 4. 
In this batch, the temperature was adjusted to 153.degree.-158.degree. F. 
before dumping the suspension out of the kettle. 
Finished samples were taken from this batch for chemical analysis. 127 
8-pound jars (approximate weight) were produced in this batch. The 29th 
(early stage), 67th (intermediate stage) and 111th (late stage) jars were 
taken as samples for analysis. Each jar was sliced into five slices 
designated top, top-middle, middle, middle-bottom and bottom (see FIG. 4). 
Cores were then taken from each slice at center, middle and outside 
positions (see FIG. 4). Each core was then analyzed for total Na.sub.2 O, 
active Na.sub.2 O, % orthophosphate, and % total P.sub.2 O.sub.5. % NaOH 
and % STPP were calculated from analytical values. 
The results of the analysis are reported in the following table. "C","M" 
and "O" denote center middle and outside core samples. 
__________________________________________________________________________ 
Samp- % Total % Active % Ortho- % Total 
ling 
Sample 
Na.sub.2 O 
Na.sub.2 O 
% NaOH phosphate 
P.sub.2 O.sub.5 
% STPP 
Time 
Layer 
C M O C M O C M O C M O C M O C M O 
__________________________________________________________________________ 
Early 
top 44.1 
45.5 
45.2 
41.7 
43.3 
42.8 
57.4 
58.4 
58.5 
0.85 
0.81 
0.62 
1.9 
4.00 
2.50 
1.82 
5.55 
3.27 
top- 44.4 
44.3 
43.5 
40.5 
40.5 
40.0 
56.6 
56.8 
55.6 
0.90 
0.92 
0.93 
4.8 
4.22 
4.10 
6.79 
5.74 
5.52 
middle 
middle 
41.9 
43.6 
44.4 
36.9 
39.6 
40.4 
52.3 
54.1 
56.3 
1.34 
1.58 
1.47 
7.43 
8.80 
5.54 
10.6 
12.5 
7.08 
mid- 39.7 
40.8 
40.0 
33.4 
35.1 
34.0 
47.1 
47.4 
47.0 
3.00 
2.54 
2.45 
13.5 
16.6 
14.7 
18.3 
24.4 
21.3 
bottom 
bottom 
36.4 
37.7 
34.5 
28.5 
30.2 
26.4 
40.9 
42.0 
38.3 
3.00 
3.00 
2.90 
18.3 
20.0 
18.6 
26.6 
29.7 
27.3 
Inter- 
top 46.1 
44.8 
44.9 
43.4 
41.7 
42.4 
59.9 
57.9 
58.1 
1.00 
0.94 
1.00 
2.10 
3.00 
2.50 
1.91 
3.58 
2.61 
med- 
top-mid 
43.3 
44.5 
43.5 
39.3 
39.4 
40.1 
55.0 
56.6 
55.1 
1.57 
1.20 
1.40 
5.32 
5.00 
5.53 
6.53 
6.61 
7.19 
iate 
middle 
42.3 
42.2 
41.3 
37.2 
37.8 
37.1 
52.9 
52.9 
51.8 
0.94 
1.27 
1.40 
7.30 
6.91 
6.90 
11.0 
9.82 
9.57 
mid- 40.1 
39.0 
40.8 
33.8 
32.2 
34.8 
46.9 
46.8 
45.7 
2.34 
2.57 
2.27 
15.2 
11.9 
13.4 
22.3 
16.2 
19.3 
bottom 
bottom 
38.3 
34.4 
52.4 
31.9 
25.7 
40.8 
42.8 
44.0 
62.6 
3.00 
2.89 
3.25 
19.9 
3.34 
16.7 
29.4 
0.78 
23.5 
Late 
top 46.7 
44.2 
46.0 
43.7 
40.5 
42.3 
59.5 
56.3 
59.5 
1.30 
1.00 
0.64 
5.30 
4.80 
2.66 
6.96 
6.61 
3.51 
top-mid 
43.8 
42.9 
43.6 
39.7 
39.2 
39.9 
55.3 
54.2 
55.6 
1.51 
1.50 
1.20 
5.94 
6.00 
4.70 
7.71 
7.83 
6.09 
middle 
40.3 
42.3 
41.6 
35.2 
37.5 
36.5 
49.7 
53.0 
52.4 
1.92 
1.56 
1.50 
8.80 
7.10 
6.35 
11.9 
9.64 
8.44 
mid- 38.0 
37.1 
38.1 
31.0 
30.1 
31.2 
43.9 
43.5 
45.3 
2.60 
2.32 
2.45 
15.9 
14.0 
12.8 
23.1 
20.3 
18.0 
bottom 
bottom 
35.1 
34.0 
36.7 
27.6 
24.2 
30.0 
38.6 
37.6 
40.8 
3.33 
3.10 
3.14 
20.0 
18.8 
19.8 
29.0 
27.3 
28.9 
__________________________________________________________________________ 
The data show that the composition is stratified (i.e., non-uniform) from 
top to bottom within the jar with respect to each of the parameters 
tested. Of particular interest is the variation of the active Na.sub.2 O 
and STPP. Using an average of the figures reported for the center, middle 
and outside samples in each top and bottom layer, active Na.sub.2 O varies 
from top to bottom by 33.5% at early stages of production, by 22.8% at 
intermediate stages and by 35.3% at late stages. STPP varies from bottom 
to top by 87.2% at early stages of production, by 84.8% at intermediate 
stages and by 79.9% at late stages. Thus, the analytical data demonstrate 
that there is a broad range of variation of active Na.sub.2 O and STPP in 
the stratified product. 
EXAMPLE 8 
Jars produced in Example 7 were tested in a commercial washing machine. 
FIG. 5 shows the condition of the washing machine after it had been 
routinely using a prior art high alkalinity solid cast ware washing 
detergent of the following formulation: 
______________________________________ 
water 14.5 (wt %) 
NaOH (bead) 48.5 
sodium carbonate 17.35 
(light soda ash) 
polyacrylic acid 4.26 
(MW 4500) 
tetrasodium EDTA 4.26 
STPP (light) 10.41 
surfactant (CF-76)/ 0.61 
defoamer 
______________________________________ 
This prior art product was uniformly cast. Heavy lime deposits and scaling 
can be seen on the vertical wall of the machine. A photograph was taken of 
the wash tank (FIG. 6) when use of the prior art product was discontinued 
before changeover. Use of the product was discontinued by removing the 
partial jar from the dispenser and replacing it with the composition of 
Example 6. No adjustment was made to any control devices or operating 
conditions or methods. No acid descaling or special steps were taken other 
than use of the composition of Example 6. 
Normal washing procedures of the customer were followed using jars of the 
composition of the present invention made in Example 6. Near the end of 
the fourth jar of composition a second photograph was taken (see FIG. 6). 
This photograph shows that the heavy lime deposits and scaling have been 
removed as a result of the boost in phosphate content provided by the 
composition of the present invention. This cleaning result was achieved 
solely by use of the composition of the present invention in the normal 
course of operation of the machine. No down time was required. Dishes and 
glasses run through the machine after conversion to the composition of the 
present invention were examined and found to be spot free and had a 
bright, renewed appearance. 
EXAMPLE 9 
The effect of incorporation of other typical desirable detergent builders 
and components in the near monohydrate ratio sodium hydroxide solution was 
examined. Granular anhydrous sodium metasilicate was used in a formulation 
as follows: 
______________________________________ 
NaOH (50% wt soln.) 130 (gms) 
sodium carbonate 24 
(dense soda ash) 
LMW45 (surfactant) 18.2 
NaOH (solid bead) 75 
sodium glucoheptanate 6 
CF76 (surfactant) 1.5 
antifoam 0.3 
anhydrous sodium metasilicate 
45 
______________________________________ 
This sample was prepared in the same manner described in Example 4, with 
the metasilicate being added in place of the STPP. This composition 
stratified in a manner similar to those described previously.