Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~CTIUS 9+/09835
2 ~ ~ 0 ~ ~ 2 5~ Rec'd P~ ~ 'PTO 0'~ A U G ~~~~~
1
STRATIFIED SOLID CAST DETERGENT COMPOSITIONS
AND METHODS OF MAKING SAME
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
ser~rice 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. Patent Nos. RE32,818 and 32,763).
However, providing a constant concentration of all
formulation components can provide significant
disadvantages.
AM~~DED SHEET
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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.
~~ .. .. .. _
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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
WO 95/06713 PCT/US94/09835
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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.
Su_~ary 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
the 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
WO 95/06713 PCT/US94/09835
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
5 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 (SHIHP), and sodium trimetaphosphate
(STMP), along with their other alkali metal analogs,
particularly potassium analogs (such as, for example,
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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
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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
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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
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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.
Brief Description of the Figures
Figs. 1 and 2 depict a solid cast detergent
WO 95106713 PCT/ZJS94109835
production of a preferred embodiment of the present
invention. Fig. 2 is a cross-sectional view of the
container shown in Fig. 1 taken along line 2-2.
Fig. 3 depicts the preferred embodiment of
5 Figs. 1 and 2 in position for use in a ware washing
machine.
Fig. 4 depicts a method for sampling a
composition of the present invention for chemical
analysis to determine the amount of stratification.
10 Fig. 5 is a photograph of the interior of a
commercial ware washing machine which had used a prior
art solid uniformly cast alkaline detergent composition.
Fig. 6 is a photograph of the interior of the
same machine after use of a preferred composition of the
present invention.
~7escription 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 paint 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
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the product application. Preferably, the temperature is
adjusted to from about 130°F to about 195°F, preferably
from about 148°F to about 163'°F or about 135°F to about
168°F, most preferably from about 153°F to about 158'°F.
Below 148°F it may become more difficult to achieve
repetitively uniform stratification. Below this
temperature some foririulations 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°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
deterioratibn 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
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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 ortho-phosphate 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°F to about 168°F have been found to
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produce stratification without significant reversion in
typical formulations. Temperatures of from about 148°F to
about 163°F provide particularly desirable results.
Temperatures above about 170'°'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 compostions 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°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. 0.75mm sodium hydroxide pellets (bulk
density 1,150 kg/m3 or about 73 lb./ft3) 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
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the metal hydroxide. xn larger bead or granular form,
sodium hydroxide and/or alkaline silicate (such as for
example anhydrous metasilicatel may be used as stratified
coanponent s .
S The compositions can also contain a source of
available halogen. Any organic ox inorganic material
which provides active halogen, particularly chlorine
(such as in the form of hypochlorite ox Cls?, can be used.
$xamples of appropriate chlorine sources include alkali
metal and alkali eaxth metal hypochlorite, hypochlorite
addition products, chloramines, chlorimines, chloramides,
and ch7.orimides. Compounds of this type include sodium
hypochlorite, potassium hypochlorits, monobasic ca:.cium
hypochlorite, dibasic magnesium hypochlorite, chlorinated
trisodium phosphate dvdecahydrate, potassium
dichloroisocyanurate, trichlorocyanuric acid, sodium
dichloxoisocyanurate, sodium dichlaroisocyanurate
dihydrate, 1,3-dichloxo-5, 5-dimethylhydantoin, N-
chlorosulfamide, Chloramine T, Dichloramir~e T, ~.oramine
B arid Dichloramine B. Stability is maximized When these
materia7.s are used in granular fozm and added last before
the compvnent(s) to be stratified. Encapsulated chlorine
sources anay also be used to provide better in-processing
and storage stability,
The compositions may also contain surfactants,
including nonionic surfactants, an:,o~nic surfactants,
arnphoteric surfactants and cationic surfactants.
Preferred materials for machine spray washfng application
are~those nonionic surfactants With defoaming
characteristics (such ae those sold under the "Triteri CF°
ser~.es by Union Carbide) . Preferred surfactants include
alkali metal alkyl benzene sulf onates, alkali metal alkyl
sulfates, and mixtures thereof. Nonionic surfactants can
also be used alone or'in co~mb~.nar.ia~n with anionic,
amphotexic ar cationic surfactants. Suitable nonionic
surfactants include polyethylene oxide condensates of alkyl
phenols, products derived i'rom the condensation of
*Trade-mark
CA 02170902 2004-10-26
61293-360
ethylene oxide with the reaction product of pragylene
oxide and ethylene diamine, the condensation product of
aliphatic fatty alcohol.s with ethylene oxide as well as
amine oxides and phosphine oxides. Products sold under
5 tha trademark ~~pluronic~~ provide desirable resuJ.ts.
The compositions of the present invention may
contain a supplemental water conditioning agent to
enh3.nCe performance by sequestering calcium and/or
magnesium ions at lower phosphate levels ox to replace
10 phosphate where its presence is undesirable. These
include organic chelacing/sequestering agents (such as
glucvnates, citrates, glucoheptanates, phosphonates,
EDTA, nitrilo triacetate (NTA), polyacrylic acid of
molecular weight of about x.,000-4,000 or greater in the
15 usef~:z range of sequestrants alone with copolymers and
blends of the acrylic/maleic or other forms. These
materials may be incorporated at ar~y useful level from
less than 1~r to more than 7.5~C . xn addition, the
compositions of the invention may contain any functional
defaamer which may or may not have surface active
properties.
The compositions of the invention can be made
by combining the components of the fozmulation in
suitable mixing eq~,~ipment. 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 temperatura of the detergent
suspension is adjusted to the desired range. ~n
formulations ~mploying solid metal hydroxide as an active
ahkalinity source. .dissolution of the metal hydroxide is
exothermic and generates heat. Minimal heat is reauired
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 susgension may also be
cooled, if necessary, to pxovide the desired temperature.
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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 hydration 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
300g 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°F.
The required amount of dense granular sodium
tripolyphosphate (density: 62 lb./ft3; particle size: >95~
on 100 mesh (U. S.) and >75% on 0.5mm (metric)) was then
added quickly and mixed for approximately one minute.
The temperature was then verified to be just below 150°.
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
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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°. 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 23.2523.2523.25 23.2523.25
(wt%)
sodium hydroxide 51.75 51.7551.7551.75 51.7551.75
(bead)
STPP (dense granular) 20.0 20.0 20.0 5.0 5.0 10.0
3 5 anhydrous sodium
metasilicate S.0 --- --- ___ ___ ___
sodium carbonate
(light soda ash) --- 5.0 --- --- 5.0 15.0
sodium carbonate
4 0 (dense soda ash) --- ___ 5.0 ___ ___ ___
sodium hydroxide
(bead) ___ ___ ___ 20.0 15.0 ___
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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 23.2523.2523.25 23.25
23.25 23.25
sodium hydroxide
(bead) 51.75 51.75 51.7551.7551.75 51.75
51.75 51.75
STPP (dense granular)20.0 20.0 20.020.020.0 20.020.0
20.0
polyacrylic acid
2 (4500 Nib 5.0 ___ ___ ___ ___ ___ ___ ___
0
acrylic malefic
copolymer
(SoKolan CPS) ___ 5.0 ___ ___ ___ ___ ___ ___
citric acid ___ ___ 5.0 ___ ___ ___ ___ ___
2 gluconic acid (50%)--- --- --- 5.0 --- --- --- ---
5
sodium glucoheptanate___ ___ ___ ___ 5.0 ___ ___ ___
trisodium nitrilo
triacetate ___ ___ ___ ___ ___ 5.0 ___ ___
tetrasodium EDTA ___ ___ ___ ___ ___ ___ 5.0 ___
3 phosphonate
0
(bequest 2000) ___ ___ ___ ___ ___ ___ ___ 5.0
The inclusion of these additives did
not
appear
to
35 appreciably change tioncharacteristics
the stratifica on
a visible basis een in priorsamples without the
s
additives.
W O 95/06713 PCT/US94/09835
19
Example 4
Samples were made including factants
sur and
defoamers to the following
formulations:
A B C D E F
water 23.25 23.25 23.25 23.25 23.2523.25
sodium hydroxide
(bead) 51.75 51.75 51.75 51.75 51.7551.75
STPP (dense granular)20.0 20.0 20.0 20.0 20.0 20.0
polyacrylic acid
_
(4500 MVO 5.0 3.0 3.0 3.5 3.5 4.0
nonylphenol ethoxylate
(N-95) ___ ___ ___ 1.5 ___ ___
ethylene oxide-
propylene oxide
(Pluronic L) ___ ___ ___ ___ 1.5 ___
modified aryl aloxylate
(Triton CF) ___ ___ ___ ___ ___ 1.0
dodecyl benzene
2 sulfonic acid
0
(anionic) 2.0 ___ ___ ___ ___ ___
Miranol JEM
(amphoteric) ___ 2.0 ___ ___ ___ ___
BTC 2125M (quaternary
2 aryl) ___ ___ 2.0 ___ ___ ___
5
The inclusion of these additives did not visibly affect
the observed stratification.
WO 95/06713 PCTlUS94/09835
Example 6
A production-sized batch (1000 lbs.) of the
following formulation was made:
NaOH (50% soln.) 427 lbs.
5 sodium carbonate 30
(light soda ash)
polyacrylic acid
(MW 4500) 60
NaOH (solid) 260
10 Triton CF76 8
antifoam 1.5
sodium glucoheptanate 15
STPP (dense granular) 200
15 The batch was made according to the general steps
described in Example 4. In this batch, the temperature
was adjusted to 153-158°F before dumping the suspension
out of the kettle.
Finished samples were taken from this batch for
20 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 NazO, active Na~O, % orthophosphate,
and % total P205. % 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.
WO 95/06713 2 1
PCT/US94/09835
O H O ~p .P.Il rv ~ P
rl n N N n, n P ~ rv ~ b ~ N
d
d
V7 ~ N ~ n N .. N r
rv o n
H N r rv H f~lb P ~ O b a N N
b b n
U ' '. r
b .. N P b C ~ 0
~ O rvN n ..rv j
r ~ b
I
O Si S~ ' g g .~ O b
N Y .. ~ N ..~ P
N P b r
N
O
b 0 ~ p P m O ~ a
a. Y r N 6 , o
~ n
o ~ v n r
U P r; ~ P P
~ ! n r ..rv b r ~ H P H
n W r
C P g . ~ rv n 1
O r N r r ~
N 1~1O r w N f~l
I
S w rv ~ g m m
~ o r r N r r r N
a
$ S S S n
0 0 . r P N r P N n
n n r o n r ~
b o
O u~ N Y~ r ~'S~ N N f '~ uwfVf ~ I Y
O
r O P vp P O 0 m
~ ~ ~
r f N ~ ~ f 1 ~ M N f 1~1
N
f ~p1~1 P P O P Ili11 P m
v h ~ 1 r n
N N t t
O 0 1 O
P N
t O
t Y N N a 1 wl M Y v ~ ~ w1
7
O
./..t
N
f 1 ~ 1~1~ 1 ~ 1~1~ N M ~ N
1
U n o ! m n rv n n o b
n ,. $i n
, ! m n a $i m , N
O N P rv O b
1 f 1 1 ~ 1 Y f ~ T f 1 M
Y1 11V a W O O
n N
1 Y 1 f A~1f N ~ 1~1r ! 1 InlOI
O
t6 U : ~ ~ n m r,o
r r r Ri ~ r Y r $ ~i ~ ! r ~ n
N H
~
~ v N .~E ~ ~ .o
'O
E ~ ~
E
rt ., _ o + a v . ~ ' ~ .n
~ , o
o _ ~ ~ E ~ n ~ E 'o a
E ,
+~ y _ ~E .
~E . E
d
I
~
L N .N
~
lp W y J
N
r-
E
WO 95/06713 PCT/US94/09835
22
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 Na20 and STPP.
Using an average of the figures reported for the center,
middle and outside samples in each top and bottom layer,
active Na20 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 Na20 and STPP in the
stratified product.
Exam l
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
(light soda ash) 17.35
polyacrylic acid
(MW 4500) 4.26
tetrasodium EDTA 4.26
STPP (light) 10.41
surfactant (CF-76)/
defoamer 0.61
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
WO 95/06713 PCT/US94/09835
23
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)
LNlW45 (surfactant) 18.2
NaOH (solid bead) ~5
sodium glucoheptanate
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.
