CA1102653A - Detergent composition - Google Patents

Abstract

DETERGENT COMPOSITION
Tom Ohren and Burton H. Gedge, III

ABSTRACT OF THE INVENTION
A detergent composition is formulated containing a mag-nesium insensitive surfactant system, a calcium specific builder system and a magnesium specific builder system. A process for utilizing the composition is also described.

Description

BACKGROIJ-l~D OF THE I2~VENTION
l. Field of the Invention .
This invention relates to cleaning compositions particularly those adapted for cleaning fabrics.

2. D cription of the Art Compositions useful for the cleaning and treating of fabrics typically contain surface-active agents (surfactants), detergency builders, and optional ingredients such as dyes, : ' brighteners, enzymes, bleaches, and soil suspending agents.
`~ 15 Detergent compositions which are to be utilized in modern ,, :
- washing machines often contain alkali me~al silicates hereinafter described to provide a source of alkalinity ~ and to protect against the corrosion caused by other common - 1 detergent ingredients.
Surface active agents, hereinafter referred to as "sur-factants" are generally defined as materials that reduce the surface tension in aqueous solutions between liquid and solid surfaces such as fabrics. The basic reason for using surface active agents is to exert an emulsifying action to aid in the removal of soil from the surface to be cleaned.
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Nonionic surface active agents are particularly useful in emulsifying oily soils such are as obtained when motor oil or other petroleum products soil fabrics. Anionic surfactants are particularly useful in removing body soils and earth, such as clay soils from fabrics. The zwitterionic surfactants are particularly use~ul in removing body soils, that is, the fatty acids~ triglycerides, and fatty acid triglyceride complexes which enter clothing by way of perspiration. Due to the unique balanced charge of zwitterionic compounds, these surfactants are also extremely effective in cleaning earth soils and in removing oily substances from fabric substrates~ Ampholytic surfactants are generally present in detergent compositions in their anionic Eorm and thus function equivalentIy with anionic surfactants. Ampholytics also have a ~witterionic character and when used in that form have substantially similar effects on the removal of soil to that of the true zwitterionic compounds. Cationic surfactants are typically not particularly effective in their ; ability to clean fabrics but are more often used for their ability to soften fabrics. Typical of cationic sur~actants are materials such as dimethyl distearyl ammonium chloride, and other quaternary ammonium compounds.
Detergent builders are generally defined as ingredients that increase the detergent power of surfactants. Builders can typically function as water softenersJ buffers, and soil suspending agents when used in detergent compositions.
The basic purpose for including detergency builders in cleaning compositions is to provide for the effective removal of calcium and magnesium ions from the incoming wash water.

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i53 The effect of removing the calcium and magnesium ions is two-fold. First, the calcium and magnesium ions have a high affinity for fatty acids present in body soil. If the calcium and magnesium ions in the wash water are not effectively controlled they interact with the body soil, rendering the removal of that soil difficult, if not virtually impossible.
The second reason for removing the hardness ions is to prevent the interaction of the hardness ions with the surfactants, particu-larly those which have anionic character. The reaction undergone by the calcium or magnesium ions in the wash water and the surfactant compound is one of association or precipitation. This reaction is undesirable from the view that the surfactant will be less effective against body soil, clay, etc.
The second effect of having detergency builders present is that of buffering a wash solution to a pH slightly in excess of 9Ø This buffering effect is useful in aiding the removal of body soils which are saponified at that pH. Not all detergency builders possess buffering capacity and, moreover, ` not all detergency builders buffer within the same pH range.
The last mentioned function of detergency builders is to aid in the suspension of soils which have been removed ` from the washed fabxics in the aqueous wash solution. This function is also quite important in that many times heavily soiled fabrics are inadvertently placed in the same wash load by the consumer with lesser soiled, light colored fabrics.
The net effect of mixing wash loads of various soiled fabrics ,

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;3 is that the removed soils are deposited upon the washed fabrics ~uring removal of the wash water. Thus builders which have the ability to suspend soils in the aqueous solution are particularly advantageous in lessening thle deposition of removed soils upon the fabrics. Tripolyphosphate and pyrophosphate detergent builders are exemplary in their ability to not only control the water hardness but to also suspend soils in the wash solution. Unfortunately, the use of phosphates has been criticized for their susceptibility lQ to promote the eutrophication or aging of natural water bodies due to the acceleration of algae growth by the phosphorus in these compounds. Thus, it is desirable to minimize or elimi-nate the presence of phosphates in detergent compositions.
The reduction or elimination of phosphate builders from detergent compositions has proven considerably difficult.
For instance, it has been speculated that on an equivalent weight basis with any other builder that tripolyphosphates and pyrophosphates will control the calcium and magnesium ; water hardness better than any other known detergent builder based on all practical considerations. Moreover, these two polymeric phosphate builders are excelleni buffers providing a desirable detergency p~ and both these materials possess admirable ~; soil suspension properties. It has proven most dificult to find any one substitute non-phosphate builder material which accomplishes all of these functions simultaneously, at anything other than ~ an exorbitant cost.

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i53 Alkali metal silicates a,re ty~ically used in detergent eompositions to proteet the` metallie surfaees of the artieles being washed or the exposed surfaces of the washing machine it-self. Such'uses are'diseussed in U.S. Patent 2rO4~,467 issued to Cleveland, June 16,' 1936.
~lkali metal sllica-tes have also been used in detergent compositions at low levels to provide desirable granular eharac-teristies. That is, the inorganle salt-like nature of the alkali metal silicate provides crisp, free-flowing granules when the detergent produet is formed by spray-drying.
It is stated in South Afriean Patent Application 73~5668 to Davies et al, published in February 1974, that alkali metal sllieates are desirable eomponents in detergent eompositions when the wash water eontains appreeiable levels of magnesium hardness.
The Davies South African Patent Application 73/5668 men-tioned above discloses that sodium earbonate may be more effeet-ively used as a detergency builder by including in the eomposi-, tion ealcium carbonate erystallization seeds. The theoretieal explanation of the funetioning of the composition taught in Davies et al is that the ealeium earbonate particles aeeelerate the rate and the extent of the removal of ealcium ions from the wash solution. The rapid removal of calcium ions from the wash solution is desirable to prevent the aforementioned interfering properties of the calclum ions. Unfortunately, the product dis-closed in Davies et al has little or no magnesium ion control capability because the solubility of magnesium carbonate is considerably greater than that of calcium carbonate. The dis-closure of detergent eompositions utilizing seed crys-tals is also found in German Patent 2,321,001.

Chang in U.S. Patent 3,74g,675, lssued July 31, 1973, teaches -that phosphate-;~ree ~eneral purpose laundry detergent compositions ma~ be ~ormulated containing the sodium salt of citric acid. P~gain, ~hile sodium citrate is relatively effect ive in removing calcium ions from the wash solution by seques-tration, the ability of the citrate to control magnesium is inadequate to effectiveLy formulate such a product.
Corkill et al in Canadian Patent 1,035,234 dated July 25, 1978 describes a detergent composition containing a crystalline aluminosilicate for use in detergent compositions to control calcium ions in the wash solution. In Canadian Patent 1~0as0~502 dated October 17, 1978 Corkill et al disclose amorphous alumin-osilicates characterized in their ability to control both calcium and magnesium ions in the wash solution.
Belgian Patent 828,753 issued to Bao-Ding Cheng, dis-closes the use of aluminosilicates as part of a "carrier"
granule in the preparation of a free-flowing granular detergent composition containing liquid nonionic detergents. The nominal ` composition described therein includes the aluminosilicate at -from about 15% to 35%, the alkali me tal silicate at from 12% to 25g6, and the anionic detergent at from 10% to 20%. The nonionic detergent is typically shown to be present at 2% by weight and the composition is stated to ha~e a pH in the wash water o~
between 9~1 and 9.3~ Detergent co~lpositions containlng alumino-silicates and anionic, nonionic, or zwitterionic surfactants and alkali metal silicates, for machine dishwashing compositions are described in U.S~ Patent 4,071,377 of August 15, 1978 assigned to Henkel & Cie.
Further detergent compositions utilizing aluminosilicates are described in Canadian Patent 1,036,455 of August 15, 1978 and in U~S. Patent 4,083,793 of April 11, 1978, bo-th of which are again assigned to Henkel & Cie.
It is noted that in the art cited above, that the CompG-sitio~s are predominatly concerned with the control of calcium ions in the wash solution. Under typical United States washing conditions, magnesium ions are present to an appreciable extent, on average, the ratio of calcium ions to magnesium ions in the wash liquid will be about 3-`1. Calcium and magnesium ions are similar in that they both have the ability to precipitate or , complex surfactants and to also interfere with the removal of soil from clothing by the precipitation thereon. Calcium and magnesium ions are however, substantially different with respect to the abillty of common detergent builders to control these materials.

i3 Typically, calcium ions are controlled much more rapidly and to a greater extent than are magnesium ions in the wash solution. Unless the magnesium which is present in the wash water is controlled effectively, a substantial amount S of the cleaning power of the detergent composition will be lost.
The development in recent years of alternative detergency builders to the polymeric phosphates has not provided effective magnesium control at a reasonable cost. That is, most of the detergency builders which have been developed as phosphate replacements do not adequately control magnesium ions.
And those which do, are o~ten of prohibitive expense. In some cases, the replacement builders are almost totally in-effective in controlling magnesium or will do so only after all of the calcium ion has been effectively removed from the wash solution.
This is to say, the replacement builders, such as aluminosilicates, which have been developed as alternatives to phosphate builders are not a complete substitute for polymeric phosphate-built detergent products when used alone. The simplest solution to detergent compositions which are built with calcium specific builders is to also include in the composi-tion a magnesium specific builder.
Woxk to develop magnesium specific builders for inclusion in detergent compositions has for the most part been frustrating due to the very costly expense of research plus the fact that ; most new bùilders are much more expensive than readily available ~f,~i ~

materials, and that complex safety considexations must be answered before pxoduct changes can be effected.
5urprisingly~ the problem of obtaining a magnesium specific builder has been solved by the discovery that one of S ~he components which is invariably presen~ in heavy-duty laundry compositions, can be adapted to provide for effective magnesium control in the wash solution.
This material is the alkali metal silicate which is previously mentioned as present in detergent compositions to 10 provide desirable granular characteristics and to lessen the t corrosive tendency of other detergent components. This discovery, described more fully later in the specification, is that a specific narrow range of SiO2:Na~O ratios when used at higher than normal levels can provide in the wash solution a 15 sufficient amount of a species of silicate which is specific in its control of magnesium ions in the wash solution. It goes without saying, that as the alkali metal silicate must be present in a sma11 amount in any event in laundry detergent ~; compositions, that it is extremely desirable to increase the 20 amount of this component in the composition to achieve magnesium control as well as the other desired properties.
It is therefore an object of the present invention to provide a superior detergent product which does not contain sequestering phosphate builders.
It is yet a further object of the present in~ention to c~mbine a magnesium insensitive surfactant, a calcium specific builder, and a magnesium specific builder, to provide optimal detergency.

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i3 It isi a fu~ther object of the present inyen.t~ion to utili2e an alkali metal silicate in a particular form to spe-ci~ically control magnesium ions in an aqueous solution.
It is yet a further obiect of the present invention to provide a process for the control of magnesium ions in an ~:
aqueous solution by the use of alkali metal silicates.
Throughout the specification and claims, weights and ratios are by weight unless otherwise indicated and temperatures are in degress Centigrade unless otherwise stated.
SUMMARY OF THE INVENTION
The present invention provides a said form detergent composition substantially free of tripolyphosphate and pyrophosphate builders comprlslng: :
(a) from about 4% to about 40% by weight of a magnesium insensitive surfactant system; ~ :
: (b) from about 13~ to about 40% by weight of an alkali metal silicate having a nominal Sio2:M2O mole ratio of rom about 1.4:1 to about 2.7:1 where M is se-lected from the group consisting of sodium and potas-slum; and (c) from about 5% to about 50% by weight of a detergency builder having an affinity for calcium ions over mag- .
nesium ions in aqueous medium as defined by log K ~Ca+~- log K~Mg~ greater than 0.6 and a log KCMg~ of less than about 6, where K is the forma-tion constant of the builder for calcium or magnesium ions measured at from 20~C to 25 C at a total ionic strength of from about 0.1 to about 1.0 moles/litre;

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wherein the composition ~eleases component (b) into solution so that wh;en a 0.6 ~ram sample of the composltion is added to 500 milliliters o~ distilled water at from about 25C to about 30C
in a 1 liter round bbttom flask and the result.ing aqueous solu-tion is stirred at a constant rate of from ahout 170 rpm toabout 175 rpm by a linear blade measuring 7.62 centimeters in length, and 2.54 centimeters in height, said blade being 1.27 centimeters from the bottom of the flask, said aqueous solution will deIiver a filtrate containing at least about 65 ppm SiO2 after about 60 seconds when filtered through a 47 millimeter *

: diameter "Millipore" filter, said filter having two circular 5 micron "Metricel" filter discs 47 millimeters in diameter, said d.iscs being concentrically one atop the other in the filter, said aqueous solution being forced through said filter and the discs by a vacuum aspirator located below the filter and the discs, said composition having a p~ of from about 9.8 to about 10~4 at the intended use concentrations.
A further more specific aspect of the present invention is a granular detergent composition, substantially free of tri-polyphosphate or pyrophosphate builders, comprising:
(a) from about 4% to about 40% by weight of a nonionicsurfactant;
(b) from about 13% to about 40% by weight of an alkali metal silicate having a nominal SiO2:M2O mole ratio of from about 1.4:1 to about 2.7:1 where M is se-lected from the group consistinq of sodium and potas-siu * Trademark ~Trademark :, i3 ~c) from about 5Q to about S0~ by weight of an intimate mixture cor.lprising (i) a compound of the formula Naz~(AlO2)z' ~SiO2)j]kH2O wherein z and j are integers of at least 6; the molar ratio of z to j is in the range of from 1.0 to about 0.5 and k is an integer from about 15 to 264; said compound having a Partic:Le size diameter from about 0.1 micron to about 100 microns;
a calcium ion exchange caæacity of at least aDout 200 mg eq.~g; and a calci~n ion ex- :~
change rate of at least about 2 grains~gallon/
minute/sram; and (ii) from about 0.3 parts to about 3 parts of an organic agglomerating compound having a melting point of from about 30C to 100C;
: wherein the composition releases component (b) into solution so ~`
that when a 0.6 gram sample of:the composition is added to S00 milliliters of distilled water at from about 25C to about 30C
in a one liter round bottom flask and the resulting aqueous solution is stirred at a constant rate of from about 170 rpm to about 175 rpm by a linear blade measuring 7.62 centimeters in length, and 20 54 centimeters in height, said blades being 1.27 centi-meters from the bottom of the flask, said aqueous solution will deliver a filtrate containing at least about 65 ppm SiO~
after about 60 seconds when filtered through a 47 millimeter : ~ diameter iiillipore filter said filter having two circular 5 micron Metxicel filter discs 47 millimeters in diameter, said discs bein~ concentrically one atop the other in the filter, ~ ' '.

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said aqueous solution beins forced through said filter and the discs by a vacuum aspirator located below the filter and the discs, said composition having a p~I of from about 3.8 to about 10.4 at the intended usage concentrations.
S Yet still another variation of the present in~ention is a spray-dried detergent composition substantially free ; of tripolyphosphate and pyrophosphate comprising:
(a) from about 4% to about 40% by weight of a water-soluble salt of an alkyl ether sulfate having from ~ ..
10 to 20 carbon atoms in the alkyl radical condensed with from 1 to 30 moles of ethylene oxide;
~b) from about 13% to about 40~ by weight of an alkali metal silicate having a nominal SiO2:M2O mole ratio of from about 1.4:1 to about 2.7:1 where ~ is selected from the group consisting of sodium and potassium; and ~c~ from about 5% to about 50% by weight of a compound of the formula Naz~(AlO2)z-~SiO2)j]kH2O wherein z and j are integers of at least 6; the molar ratio of z to j is in the range of from 1.0 to about 0.5 and k is an integer from about 15 to 264; said compound having a particle size diameter from about 0~1 micron to about 100 microns; a calcium ion exchange capacity of at least about 200 mg eq./g;
: 25 and a calcium ion exchange rate of at least about 2 grains/gallon/minute/gram and mixtures thereoi:

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wherein the composition releases component (b) into solution so that when a 0.6 gram sample of the composition is added to 500 milliliters of distilled water at from about 25C to about 30C
in a ona liter round bottom flask and the resulting aqueous solution is stirred at a constant rate of from about 170 rpm to about 175 rpm by a linear blade measuring 7.62 centi-meters in length, and 2.54 centimeters in height, said blade being 1.27 centimeters from the bottom of the flask, said aqueous solution will deliver a filtrate containing at 1~ least about 65 ppm SiO2 after about 60 seconds when filtered B through a 47 millimeter diameter Millipore filter said filter having two circular 5 micron Metricel filter discs 47 milli-meters in diameter ! said discs being concentrically one atop the other in the filter, said aqueous solution being forced through said filter and the discs, by a vacuum aspirator located below the filter and the discs, said composition having a pH
of from about 9.8 to about 10.4 at the intended use concentra-. tions.
m e present invention also relates to a process for con-trolling magnesium hardness in a wash solution comprising adding from 0.05~ to 1% by weight of detergent composition, which is substantially free of pyrophosphate and tripolyphosphate builders, comprising:
. (a) from about 4% to about 40% by weight of a magnesium insensitive surfactant system;
(b) from about 13% to about 40% by weight of an alkali metal silicate having a nominal Sio2:M20 mole ratio of from about 1.4:1 to about 2.7:1 where M is ' ;

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i3 selected from the group consisting of sodium and potassium; and (c) from about 5% to about 50% by weight of a detergency builder having an affinity for calcium ions over magnesium ions in aqueous medium as defined by log K[Ca +] - log K[Mg++] greater than 0.6 and a log KEMg ] of-less than about 6, where K is the formation constan~ of the builder for calcium or ma~nesium ions measured at from 20C to 25C at a total ionic strength of from about 0.1 to about 1.0 moles/liter;
wherein the composition releases component (b) into solution so that the wash solution contains at least about 65 ppm SiO2 after about 60 seconds, said wash solution having a pH bf from about 9.8 to about 10~4, DETAILED DESCRIPTION OF THE INVENTION
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The present invention is directed to a unique detergent product which, simply stated, contains a magnesium insensitive surfactant system, an alkali metal silicate presented into the wash solution in such a form that it is masnesium specific in its building capability and a calcium specific cobuilder. ~ach of the foregoing components is discussed below.
SURFACTANT
The first component of the present invention is the magnesium insensitive surfactant. For the purposes of this invention a surfactant is magnesium insensitive if the surfactant has less complexing ability for magnesium ions than does the silicate :, .:

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of the present invention. Complexing ability is defined as as~ociation,sequestration, or precipitation. Precipitation is of course where the solubility product of the surfactant and the magnesium ions is such that a precipitate will eventually form between the two components in an aquleous wash solution.
Sequestration on the other hand is defined as the formation of a stable entity which is highly resistant to removal of the magnesium ions from the complex and which will not precipitate out in a normal wash solution. Association is defined as the phenomena where the magnesium and the surfactant are neither in the precipitating or sequestering mode but rather in a mode approximately halfway between the two systems. That is to say an association is somewhat less stable than true sequestration and also resists growth to form a precipitate which would then fall out of the wash solution.
The formation constant Kl for a surfactant and magnesium is written according to the following reaction:

(1) Mg++ + Sn = Mg(S) wherein Mg is the magnesium ion in an aqueous solution and S
is the surfactant having an anionic charge n. The charge of the surfactant is 0 for nonionic surfactants and zwitterionic surfactants and -1 or more for anionic surfactants and ampholytic surfactants (when the ampholytic surfactant is in its anionic state).
The actual formation constant Kl for a monovalent ~ anionic surfactant is defined as .~

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(2) Kl= [Mg(S)_]

The formation constant is me~sured at 20C with an Orion divalent electrode at a total ionic strength of 0.01 as defined by the equation ~ -~

where c represents the concentration of an individual ion and ~-z its charge. The foregoing reference to ionic strength is discussed in detail in Chapter II of Complexation in Analytical Chemistry by Anders Ringbom, copyright 1963, John Wiley & Sons, New York and London, Interscience Publishers.
For nonionic and æwitterionic surfactants the value of K
is 0 as the complex described in equation (1~ does not form.
Anionic and ampholytic surfactants have positive values for K
as shown in Table 1 below.
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Table 1 Surfactants K ~Formation ' 1 Stren~th) Tallow alcohol 14 x 103 sulfate (TAS) ~ Coconut alkyl 3 : sulfate (CNAS~ 9 x 10 Alkyl benzene sulfonate ~ABS) 12 x 10`
Cl~* olefin **
sulfonate C12. paraffin **
sulfonate 1 (R2) 2N (CH2cH2o) XS03 ***
C 4 alcohol con-~ensed with 4 ;: moles of ethylene oxide 0 C13 fatty acid **
20~ soap : ~14-16 alcohol condensed with ; 2.25 moles of ethylene oxide 3 and sulfated ~.2 x 10 ~14-16 alcohol condensed with , 3 moles of . 3 ethylene oxide 0.8 x 10 . .
;: 30 * The subscript numbers used above with relation to carbon ~ atoms (C~ indicate the mean chain length of the alkyl .
:` or alkenyl radical involved. The anionic surfactants listed above have sodium cations.
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** These surfactants have Kl values so high that nearly all of the magnesium ions in solution are complexed.
*** Rl=C8 0, R2=1 5 although each R2 may differ in this range, : and X=~-30. Here Rl is C16~ R2 are both methyl, and X = 8.

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In the test descri~ed above, the alkali metal silicate of the present invention has a stability constant with respect to magnesium ions of about 6x103. Thus those surfactants having Kl greater than the silicate of the present invention are termed magnesium sensitive or interfering.
~t is to be understood however, that the Examples in , ~ .
the Table are not intended to be limiting and that one truly skilled in the art will, upon examining other surfactants r be able to determine whether or not a given surfactant is magnesium :
I0 insensitive.
Otherwise stated, surfactants are a highly soluble specïes even when employed in the form of detergent granules. There-fore, lf the surfactant is readily soluble in solution it can compete with the alkali metal silicate for the magnesium ions ~15 present.
The interfering surfactants, that is those with Kl values for magnesium greater than that of the silicate, are primarily anionic and should not be used as the sole surfactant.
It has been discoveredl as later described, that some interfering anionic surfactants can be used provided that the solubility of the interfering surfactant is less at a given point in time j than that of the filtrate SiO2.
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~ Surfactants which are useful in the present invention, ~: :
as was previously stated, are those which are magnesium insen-sitive or those which can be made to be magnesium insensitive.

Preferred levels of the magnesium insensitive surfactant system are from about 6% to about 30~, preferably about 7% to about 20% by-weight. If the insensitive surfactant system is primarily , , .

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; -- 19 --nonionic a mQre pxe~e~red level is from about 8% to 12% by weight.
All nonionic surfactants are magnesium insensitive. Such surfactants are preferabLy the ethylene oxide and/or propylene oxide condens~ates o~ alcohols and such alkoxylates condensed with alkylbenzene. By structural formula such materials are described as RO - (CH2CH2O)nH, where R is an alcohol or alkyl-benzene radical and n is the number of moles of ethylene oxide ~or propylene oxide) which is condensed with the hydrophobic moiety. Suitable materials of this general definition useful in ~-the present invention have alkyl valùes of from about 8 to 25 carbon atoms in the alkyl radical and from 1 to 50 alkoxy units.
Preferred nonionics are disclosed in the commonly assigned Canadian copèndin~ 'application of Collins, Sexial No. 222,185, filed March 17, 1975, sald application being entitled DETERGENT CQMPOSITIONS, and Canadian Pa-tent No. 1,040,962 of LaGasse,~ Storm and Perry, issued October 24, 1978, said patent being entitled NONIONIC DETERGENT COMPOSITION.
Additional suitable nonionic surfactants include mate-rials havlng the formula R'R2R N ~ O (amine oxides) where R isan alkyl group containing from about 10 to 28 carbon atoms and from about 0 to 2 hydroxy groups and from about 0 to about 5 :` ~ ,' ` 25 :
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i3 ether linkages while R2 and R3 are selected from the group consisting of alkyl radicals and hydroxy alkyl radicals containing from about 1 to about 3 carbon atoms. Specific examples of amine oxide detergents include: dimethyldodecylamine oxide, dimethyltetradecylamine oxide, ethylmethy:Ltetradecylamine oxide, cetyldimethylamine oxide, dimethylstearylamine oxide, cetylethyl-prvpylamine oxide, diethyldodecylamine oxide, diethyltetradecylamine oxide, dipropyldo~ecylamine oxide, bis-(2-hydroxyethyl)dodecyl-amine oxide, bis-[~-hydroxyethyl)-3-dodecoxy-1-hydroxypropyl-amine oxide, ~2-hydroxypropyl)methyltetradecylamine oxide, dLmethyloleylamine oxide, dimethyl-~2-hydroxydodecyl)amine oxide, and the corresponding decyl, hexadecyl and octadecyl homologs of the above compounds.
While phosphorus-containing compounds are not desirable for inclusion i~ ~etergent compositions due to their susceptibility to promote algae growth in sewage, nonionic detergents such as phosphine oxides having the formula RlR2R3P ~ O, wherein Rl is an alkyl con~aining from about 10 to 28 carbon atoms, from about 0 to 2 hydroxy groups, and from about 0 to 5 ether linkages and where R2 and R3 are selected from the group consisting of alkyl radicals, hydroxy alkyl radicals containing - from 1 to about 3 carbon atoms, are also useful surfactants within the scope of the present invention.
~: Specific examples o~ the phosphine oxide detergents include: dimethyldodecylphosphine oxide, dimethyltetradecylphos-phine oxide~ ethylmethyltetradecylphosphine oxide, cetyldimethyl-phosphine oxide, dimethylstearylphosphine oxide, cetylethyl-propylphosphine oxide, diethyldodecylphosphine oxide, diethyl-~:~ tetradecylphosphine oxide, dipropyldodecylphosphine oxide, bis-' ~ 21 ~

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(hydroxymethyl~dodecylphosphine oxide, bis-~2~hydroxyethyl)-dodecylphosphine oxide, (2-hydroxypropyl)methyltetradecylphosphine oxide, dimethyloleylphosphine oxide, and dimethyl-(2-hydroxy-dodecyl1phosphine oxide and the corresponding decyl, hexadecyl, : S and octadecyl homologs of the above compounds.

Further suitable surfactants for use in the present invention include materia}s having the formula O

Rl - S -- R2 O these sulfoxide surfactants wherein Rl is an alkyl radical containing from about 10 to about 28 carbon.atoms, from about O to about 5 ether linkages and from O to about 2 hydroxyl substituents wherein R2 is an alkyl radical containing from 1 to 3 carbon atoms, and from 1 to 2 hydroxyl groups. Examples of such materials include:
octa~ecylmethyl sulfoxide, dodecylmethyl sulfoxide, tetradecyl-~ methyl sulfoxide~ 3-hydroxytridecylmethyl sulfoxide, 3-methoxy-: tridecylmethyl sulfoxide, 3-hydroxy-4-dodecoxybutylmethyl sulfoxide, octadecyl 2-hydroxyethyl sulfoxide, and dodecylethyl ~ ~0 sulfoxide.
~ Preferably the amine oxide, the phosphine oxide, and the sulfoxide surfactants described above contain from 12 to 18 carbon atoms in the long chain alkyl radical and methyl groups for the respective number of short chain alkyl radicals.

Zwitterionic surfactants are also especially useful in the present invention because they have little or no affinity .

for magnesium ions in the wash solution. Such materia}s are described as derivatives of aliphatic guaternary ammonium and phosphonium or tertiary sulfonium compounds, in which the cationic atom may be part of a heterocyclic ring, and in whic~
the aliphatic radical may be straight chain or branched, and whe~ein one of the aliphatic substituents contains from about 3 to 18 carbon atoms, and at least one aliphatic substituent contains an anionic water-solubilizing ~roup, e.g., carboxy, sulfo, sulfato, phosphato, or phosphono. Examples of compounds falling within this definition are 3-(N,N-dimethyl-N-hexadecyl-ammonio)-2-hydroxypropane-1-sul~onate, 3-(N,N-dimethyl-N-hexa-decylammonio)propane-l-sulfonate, 2-(N,N-dimethyl-N-dodecylammonio~-acetate, 3-(N,N-dimethyl-N-dodecylammonio)propionate, 2-(N,N-dimethyl-N-octadecylammonio)ethyl sulfate, 2-(trimethylammonio)-ethyl dodecylphosphonate, ethyl 3-(N,N-dimethyl-N-dodecylammonio)-pxopylphosphonate, 3-(P,P-dimethyl-P-dodecylphosphonio)propane-l-sulfonate, 2-(S-methyl-S-tert. hexadecylsulfonio)ethane-l-sulfona~e, 3-(S methyl-S-dodecylsulfonio)propionate, sodium 2-(N,N~dimethyl-N-dodecylammonio)ethyl phosphonate, 4-(S-methyl-S-tetradecylsulfonio)butyrate, 1-(2-hydroxyethyl)-2-undecyl-imidazolium-l-acetate, 2-(trimethylammonio)octadecanoate, and ; .~!
3-(N,N-~is-(2-hydroxyethyl)-N-octadecylammonio)-2-hydroxy-propane-l-sulfonate~ Some o~ these detergents are descxibed in the following U.S. Patents: 2,129,264; 2,178,353; 2,774,786;
~;25 2,813,898; and 2,828,332 ., .

. ~ .

6~3 ~dditional z~itterionic synthetic detergents which are highly preferred in the present invention include those compo sitions discribed in U.S. Patents 3,925,262 and 3,929,678 issued to LaughIin et al issued December 9, 1975 and December 30, 1975 respectively, and in U.S. patent 3,929,678 oE December 30, 1975 to Laughlin et al.
Ampholytic surfactants are also useful in the present invention It is noted that ampholytic surfactants under the pH conditions ~of the present invention will have an anionic rather than a zwitterionic character in the wash solution. Thus ;
while true zwitterionic surfactants are useful per se in the present invention, it will be necessary to determine the mag-nesium stability constant for ampholytic surfactants as is done for anionic surfactants.
Examples of ampholytic surfactants which can be selected for use in the present invention include sodium 3-(dodecylamino)-propionate, sodium 3-(dodecylamino)propane-1-sulfonate, sodium 2-(dodecylamino)ethyl sulfate, sodium 2-(dimethylamino)octade- ~.
canoate, disodium 3-(N~carboxymethyldodecylamino)propane~
sulfonate, disodium octadecyl iminodiaze tate, sodium l-carboxy-` methyl-2-undecylimidazole, and sodium N,N-bis(2-hydroxyethyl)-2-sulfato-3-dodecoxypropylamine.
.
Anionic surfactants, as was noted above, are difficult to incorporate into the present invention because of the degree ~: .
~- 25 of affinity which these materials possess toward magnesium ions - in the wash solution.
, ., ~; 30 i3 Unsuitable anionic surfactants which should not be used in the present invention include paraffin sulfonates and a olefin sulfates. The difference between the former and the latter material is that the olefin sulfonates are unsaturated in the two-position relative to the sulfonate rad:ial. These materials are very soluble and highly magnesium sensitive such that they eliminate the a~ility of the silicate to control magnesium ions under any conditions except manual delay.
It has been found that alkyl ether sulfates may be incor-porat~d into the present invention as the sole suractant because such materials have less ability to complex magnesium than does the silicate of the present invention. Preferably, the alkyl ether sulfate has from 10 to 20 carbon atoms, preferably 12 to 18 carbon atoms, in the alkyl radical and is condensed with from 1 to 30 moles~ preferably 2 to 4 moles of ethylene oxide prior to sulfation. Highly preferred alkyl ether sul~ates are those in which the total number of alkyl carbons in a ratio to the moles of ethylene oxide i5 from 8:1 to 3:1, preferably 6:1 to 4;1.
It is not fully understood why alkyl ether sul~ates may be utilized in the present invention, but it is believed related to the fact that the ethylene oxide radicals lessen the tendency of the sulfate radical to strongly bind to magnesium ions. It is noted, however, tnat wnile all alkyl ether sulfates are useful in tihe present invention that those compounds of the preferred ranges are highly desired because they are less soluble than e higher ethoxylated species and are tnus much less likely to compete with the silicate for the magnesium ions. That is, while the alkyl ether sulfates are not per se magnesium sensitive as they have lower Kl lMg } values than does the silicate the alkyl ether sulfates can still compete on a lower scale for the magnesium ions to the detriment of good cleaning.
In contrast, tallow alcohol sulfate, which differs from alkyl ether sulfate only in that the former material has no ethylene oxide constituent, is highly competitive for magnesium ; ions in the wash solution. Tallow alcohol sulfates can, how-ever, be used up to a 2:3 weight ratio with alkyl ether sulfates due to the low solubility rate of the tallow alcohol sulate under normal wash temperatures. There are usually small amounts of alcohol sulfates present in the alkyl ether sulfate due to the presence o~ unethoxylated alcohol pxecursor in the mixtures to be sulfated. Thus, tallow (C16-C18) alcohol sulfates which have an affinity for the magnesium ions more than twice that ~, of the filtrate SiQ2 may still be used in appreciable amounts : I .
-; in the detergent composition because that surfactant is not readily soluble at temperatures less than 37C provided that the tall~w alcohol sulfate is present with an alkyl ether sulfate.
Alkyl sulfates,other than tallow alcohol sulfate, may also be used in the pxesent invention providing the foregoing conditions are met. Specifically included within this defini-tion are alcohol sulfates, having from 10 to 16 carbon atoms in the alkyl radical, preferably from 12 to 15 carbon atoms in the , :
alkyl radical. An additional example of such materials is middle-cut coconut alkyl sulfate which contains approximately 65~ C12 and 35% C14 material. Lesser amounts of these materials should be used however due to their higher solubility rate.

Alkylbenzene sulfonate wherein the alkyl radical has from 8 to 18 carbbn atoms~ pre.~erably from 10 to 14 carbon ato~s, is a magnesium sensitive surfactant with respec-t to its ability to disrupt the ~agnesium controlling ability of the silicate.
It is thus noted that suhstantial quantit:ies of alkylbenzene sulfonate utilized alone would not be a suitable surfactant for the present invention unless modified so as to delay its entry into solution. In fact, the presence of alkyl ether sulfates with the alkyl benzene sulfonate do not render the latter suit-able as in the case of tallow alcohol sulfate.
~:: It has been found that alkylbenzene sulfonate can be utilized in detergent compositions of this invention provided .
: that they are spray-dried in the presence of alkyl ether sul-fates and a nonionic surfactant having an HLB of less than 10.
` 15 Such nonlonics are described in Canadian Patent 1,040,962 of .~ LaGasse et al previously referred to. A brief description of ~` alkoxylated compounds having an HLB (hydrophilic lipophilic ...
balance) of less than 10 is found in the following equations: .

: (4) :% alkoxylation where . HLB ~ - - -:- 5 ~:~ 20 :.
( ) % alkoxylation - weight alkoxy x 100 :i weight alkoxy ~ welght precursor :
. ~, :. or where the alkoxylated compound is an , ~
. ethoxylated alcohol ~ (6) % ethoxylation = weight ethoxylate x 100 -.-:: 25 weight ethoxylate~ weight ~ of the alcohol :, ~

~ "

':~ , 6~ `

While not wishing to be bound by any particular theory it is believed that the low HLB nonionic when employed at levels of from about 0.1~ to about 4%, preferably from about 0.5~ to about 3%, and more preferably from about 1~ to about 2% by weight lowers the solubility rate of the magnesium sensitive surfactant. This lower solubility rate of surfactants such as alkylbenzene sulfonates (and alcohol sulfates) in turn allows the highly soluble silicate species to reduce the magnesium ion content of the wash water to an extent greater than if the in-terfering surfactant is not so restrained. Surprisingly, thelevels of the low HhB surfactant used do not appreciably lower the filtrate silicate rate of release which must be greater than, preferably at least twice the molar release of the interfering surfactant (LAS). More pre~erably, the filtrate silicate is released three times, and most preferably four times as fast as the interfering surfactant on a molar basis. The low HLB
nonionic should be crutched with the anionic surfactants and spray dried to form gxanules rather than sprayed on previously dried .
granules as the latter rnethod inhibi-ts silicate release.
It is further noted that the above is merely a preferred form of restraining the interfering surfactant. Other methods include manual time delay by adding the silicate before adding the magnesium sensitive surfactant or encapsulation of the inter-fering surfactant.

When the surfactant system of the present invention in-cludes magnesium sensitive surfactants in the manner described above, the total surfactant system is referred to as -the mag-nesium insensitive surfactant system.

- 2~ -A pre~erred surfactant system employing ma~nesium insen-sitive and magnesium sensitiVe surfactants includes from about 0.1% to 4~ b~ weight of ~ nonionic surfactant having an HLB of less than 10, and from about 2% to 15% each of an alkyl ether sulfata, an alkyl benzene sul~onate and an alcohol sulfate (preferably tallo~. PreferabIy the foregoing anionic surfact-ant mixture is 4% to 9% by weight of each. It is also preferred that the all~yl benzene sulfonate not be in excess o~ the alkyl ether sulate by an amount greater than 1.5:1, preferably not greater than 2.7:2.
,. . .
~` SILICATE
The alkali metal silicate component of the present inven-tion is typically expressed as having a nominal SiO2:M2O mole ratio of from about 1.4:1 to about 2.7:1, preferably ~rom about 1.5:1 to about 2.4:1, and more preferably from about 1.6:1 to about 2.2:1. Highly preferred is a silicate having a nominal molar SiO2:M2o ratio of 2.0 where M above is sodium or potas-sium, preferably sodium. This ratio is referred to as a " "nominal" SiO2:M2O mole ratio for the reason that there will be - 20 additional components in the detergent composition which will either serve as a source of M2O such as sodium carbonate (Na2O:CO2) or to deplete the M2O in the silicate (acids). The inclusion in the present composition of such additional sources :,, of M2O are desirable as -they tend to buffer the solution to within the narrow pH range described hereinafter. When the composition is formed by crutching (mixing) the silicate with other components having the ability to af~ect the M2O content of the silicate, the term "nominal" is synonymous with "input"
(raw material).

~ - 29 -Components which deplete the M2O content are not ~avored as they tend to polymerize the silicate while highly alkaline components (M2O source) must be used cautiously ~o avoid raising the pH
above the desired llmits discussed hereinafter.
The alkali me~al silicate useful in the present invention may be obtained ~rom several sources r such as Diamond Alkali or Philade~lphia Quartz. The compositions of the present inven-tion are for~ulated as a solid composition, preferably in the form of spray~drie~ detergent granules containing the silicate and preerably also containing ~le surfactant system. The sil-icate may be processed into the compositions in liquid or solid -;
form. Li~uid silicates generally contain 30~ or more water by weight of the slurry containing the silicate. Sources of alkali met~l silicate5 w~ich aO not fall wi~hin the ratios described above may be used and adjusted either initially, during the pre~
paration or t~he composition, or in use by the addition of caustic or acid to the desired range. It is preferred, however, that equili~rated liquid silicates be used in forming the solid com-, ~ .
positla~s ~s these materials have the highest silicate release rate. ~rtially dried (hydrous) silicates are ne~t in line of preference io liquid silicates. Hydrous sil:icates are a dry material having a water content of greater than 5%, preferably greater than 10~, ànd most preferably gre~ter than 15%. Silicates having less than 5% moisture are too polymerized to economically convert to highly soluble species notwithstanding their nominal ratio.
It is important that the silicate to be utilized in ~he present invention must be processed such that it will dissolve B
~ 30 ~

or disperse ~ap.idly. Most im~ortant in this regard is maintaining the silicate in a relatively unpolymerized form. The silicate should not be dehydrated and it is desirable to keep the SiO2:M2O
ratio near the desired range. Alkaline materials may be added to the wash to bring the silicate to the desired in use pH, hut ~le intimàte presence of the M2O i~ the silicate helPs to retard polymeri~ation.
It is believed that when the silicate is formulated into the detergent compositions of the present inVentiQn that the release rate of the silicate as hereinafter described indicates ., , the presence of a species of silicate which is highly specific in the control of magnesium.
An important condition in the present invention is that the in use pH ~e at or above 9.8 or the magnesium silicate com-plex will not form. A preferred pH range at the in-use concentra-- tion of the product is from about 10.0 to about 10.4, preferably about 10.1 to about 10.4. It is further highly desirable that ;~, the in-use pH instantaneously reach the above ranges and further stay in said range for at least the first 30 seconds, preferably the first minute and most preferably the first two minutes of the wash cycle. The pH of the product in use mus~ remain below about 10.4 or magnesium hydroxide floc will form which deposits on fabrics. Aside from safety considerations if the pH were to ` exceed 11, calcium silicate would form thus lessening the control of magnesium by the silicate.
By way of theory it is believed that the magnesium ions first ~ssociate with hydroxyl ions and that complex then reacts with a negatively charged silanol oxygen or hydrogen bonds to a ii3 silanol hydrogen. The complex fonmed by the magnesium and sil-icate does not precipitate and has an empirical composition of MgO:2SiO2 xH2O where x is from about 3-5.
As was stated above what is of particular importance is S that the alkali metal silicate eventually be in a rapidly soluble form such that it may control the magnesium hardness in the wash solution. If the alkali metal silicate is not sufficiently soluble or if it exists in a highly polymerized ; state~ the effective degree of magnesium control will be lessened 1~ to the point of prior art products where magnesium control via ;~
the silicate is absent.
The amount of the alkali metal silicate to be utilized in the present invention is from about 13~ to about 40~ by -weight, more preferably fro~ about 15% to about 30% by weight, l$ even more preferably from ~bout 16~ to about 25% by weight, and .,, most preferably from abvut 18% to about 22% by weight. The determination of the amount of filtrate (soluble) silicate as SiO2 which is necessary for magnesium control is described helowO
DESCRIPTION OF THE DRAWINGS

At -this point, before proceeding to discuss the remaining components in the present inve.ltlon, it will be useful to ; refer to the drawings and the method of determining the degree of silicate solubility.
Figure 1 discloses the apparatus used for determining the extent of silicate solubility~ Figure 2 shows an exploded view of the filtration apparatus.
The determination of silicate solubility is carried out ~y adding a sample (0.6 gram)of the product to be tested for 29 silicate solubility into one neck 15 of a three neck 1000 ml.

~ ~f~ ~ 5 3 round bottom flask 13 containin~ d~s*illed water which is con-tinuously stirred at a constant rate to ensure uniformity of dissolution and then at a gi~en time rapidly filtering the sample through a "Millipore" filter system.
In Figure 1, the stirring mechanism comprises the stirring shaft 11, through which the stirring blade 16 communicates with ;~ the power source 12~ The stirring shaft 11 is held in place in the center neck of the three neck 1000 ml. flask 13 by glass stirrer bearing 14. The bottom of flask 13 has been excited to `-allow communication with the "Millipore" filter funnel 24. The , lower portion of the filter funnel 24 extends into the neck of the 1000 ml. vacuum flask 20. The filter funnel 24 is held in place in the vacuum flask 20 by rubber stopper 19. Aperture 21 in vacuum flask 20 communicates with an aspirator through a hose ;~ 15 and trap. The latter three items are not shown in the drawing.
Flask 13 is held in place to the filter funnel 24 by clamp 23. Stopcock 22 in the filter funnel is maintained in the . ~ . .
closed position until it is desired to evacuate the resultant mixture formed by adding the sample to the stirred distilled water at which time stopcock 22 is fully opened.
Figure 2 shows an exploded view of the components used in the filter funnel 2~ n operation two circular 5 micron "Metricel" filter discs 17 are seated on stainless steel support - screen 18 which in turn is seated on "Teflon"~ ring 25. The assembly of the filter discs 17, the support screen 18 and "Teflon"* ring 25 are inserted concentrically into filter funnel 24 such that said assemhly is removably placed upon the interior Trademark of du Pont ~or poly (tetrafluoroethylene). It is a tough white, Waxy plastic having outstanding resistance to chemicals and water~ and is also highly heat-resistant~
Trademark ~f~ 3 ~ ~

support rib ~ithin ~ilter funnel 24. The distance (D) between the sur~ace o~ the uppermost filter disc 17 andi the bottom-most point (taken as the intersection o the long axis of shaft 11 and the arc of stirring blade 16) of stirring blade 16 is 1.27 cm.
The stirring blade 16 is geometrically described as the arc formed from a circle having a radius of 4.13 cm and cut by a chord perpendicular to thè long axis of the stirring shaft 11, said stirring shaft bisecting the arc. The surface of the stir-ring blade is linear and the chord is 7.62 cm in length. Thedistance from the point at which the stirring shaft intersects the chord to the point at which it bisects the arc is 2.54 cm.
The stirring blade is "Teflonl'* and is 0.3 cm thick.
The 5 micron pore size "Metricel" filter discs 17 are 47 mm in diameter and are available from Matheson Coleman and Bell . ~ , ! under catalog number TYPE GA-l Part Number 60003. "Metricel" is a registered trademark of Gelman Instrument Company of Ann Arbor, Mlchigan. A further description of the filtration apparatus is found in the 1975 Millipore catalog and Purchasing Guide Product Bulletin available from the Millipore Corporation, Bedford, Mas-sachusetts.
To determine silicate solubility, 500 ml of distilled water at a temperature between 25 C and 30 C is added to the three neck flas~ 13 with the stopcock 22 in the closed position and the apparatus fully assembled as in Figure 1. The stirring shaft 11 is then actuated by the power source 12 and the stir-rlng blade 16 is set in motion at a constant rate of from about 170 to 175 rpm. The rpm value can be previously determined * Trademark , . . . ~ . . .

6~i3 using a strobe light to measure the rate of stirring and sub-sequent reproduction is then obtained by xheostat settings on ~` the power source 12 (electric motor).
A 0.6 gram sample of the detergent product of the present invention to be tested is weighed out onto glassine paper and hîs sample at time 0 is added to the distilled water which is ;~ being stirred. While the detergent products do not adhere to the glassine paper, the neck and walls of the flask should be washed down with a small amount of distilled water (les~ than ,,, -5 ml i5 sufficient) to ensure that all the product is rapidly placed into thP water. This amount of 5 ml of water will amount to a relative error of less than about 1% when determining the silicate solubility. Any skilled technician after operating the apparatus described in Figure 1 will, with .,~
careul placement of the sample into the water, be able to avoid having any of the material adhere to the neck of the flask or the walls.
At the desired time after introduction of the sample, a portion of the aqueous mixture is collected by opening and closing the stopcock to allow the aqueous mixture to flow by vacuum pressure into the 1000 ml vacuum flask 20. To achieve the constant vacuum conditions the pressure in the vacuum flask is reduced by means of an aspirator pulling approximately 13 mm Hg over the ambient pressure at 20-25C (as measured at a 2~ St~ Bernard, Ohio) prior to and during the period of collecting portion o~ dissolved product r ~0 ensure reproducibility, the sample is typically collected over a four second range surrounding one minu~e, i.e., 58 to 62 seconds.

:~

~ - 35 -.:, ,.. ., ,. : , ; . :

The pQrtion collected in the 1000 ml vacuum flask 20, is ~; then detexmined for its to:tal SiO~ content from the alkali metal silicate. This may be done by any convenient fashion such as using hydrofluoric acid to convert all of the silicon presen-t ; 5 to its monomeric species. The findings are then reported as ppm SiO2 which are solubIe under the foregoing conditions.
The amount of SiO2 reIeased in ppm as determined in the test methods described abbve at one minute tbetween 58 and 62 seconds) must be at least 65 ppm, preferably at least 80 ppm, more preferably at least 90 ppm and most preferably greater than ; 110 ppm. It has been determined that-the release rate of 65 ppm .. . .
of SiO2 at one minute is the minimum necessary to control 2 `~ yrains per gallon of magnesium ion (measured as CaCO3).
The Calcium Specific Builder The next aspect of the present invention to be discussed is that of the requirement of a detergency builder which is highly calcium specific. The calcium specific detergency builder is present at from about 5 to 50~, preferably from 10 to 40%, and most preferably from 15 to 30~. Many non-phosphate builders and orthophosphates, although being very attractive ayainst calcium ions, do not control magnesium ions well. As was previously stated, pyrophosphate and tripolyphosphate builders have an almost equal degree of affinity for calcium and magnesium ions. It is essential in the present invention ~25 ~ that the calcium specific builder have a low degree of magnesium . ~
- ~ control capability or the ef~ect of preparing the product such that the silicate is highly solubIe will be lost. It is axio-; matic that as long as the silicate must be in the product in any event that its full use as a magnesium specific builder ~ 30 shbuld not be wasted.

: :
~ - 36 -~` .
~; The test for the affinity of detergent builders for ~; calcium ions over magnesium ions is defined by log K~Ca ] -log K~Mg+~] be greater than 0.6 preferably greater than 0.8, more preferably greater than 1.0 ~nd most preferably greater ~ 5 than 1.5 where K is the formation constant of the builder for ~r~` calcium or magnesium ions measured at from 20 C to 25 C at a total ionic strength of from about 0.1 to about 1.0, preferably ` at 0.1 moles per liter. The test is carried out by determining the value of K for calcium or magnesium seperately in water which contains no other ions other than the source of the calcium or magnesium, and those ions present from the detergency ~ ~ , ~ builder itself. Test methods to determine the affinity for ;~
.,.~", :
',~ calcium or magnesium of a particular builder are described in the Ringbom book referred to in page 17 of this specification.
, 15 In Table 2 below, the values for several common detergent -~ builders for the relative affinity of calcium over magnesium measured at the above described conditions using a calcium or magnesium Orion divalent electrode are set forth. The differ-ence in log K values is referred to as ~ in the table.
` 20 ~ ' : .
, :

_ 37 _ .. , , . "

.
Table 2 Builder . ~ Ca ] ~ ] _ , Sodium nitrilotriacetate (N~) 6.4 5.4 1.0 .~ Trisodium 2-oxy-1,1,3- 5 2 2 9 2 3 .~ 5 propane tricarboxylate (TCPT) Sodium citra~e 3.5 2.8 ~7 . Sodium ethylene diamine :- tetraacetate (EDIA) 10.7 8.7 2.0 ; Sodium tripolyphosphate (STP~ 5,4 5,7 3 ~ ~o Sodium pyrophosphate (TSPP) 5.05.7 -.7 .~ .
Sodlum carbonate* 6.6 4.2 2.4 ~' An al~minosilicate of the** 5.190.82 4.37 formula Nal2~(A102)12 Si2jl2J 2 .
. _ 15 * For sodium carbonate the values given are the solubility produc.s (Ksp).

** ~og of corrected equilibrium coefficient in the limit of infinitely dilute divalent metal ion as described in Friedrick holf and Helmet Furtig,Investigation of Ion Exchange Equilibrium on Synthetic Type A Zeolites, Kolloid Zeitschrift UND ZietscriftPolymere V. 206 ~1, 1965, page 48-55, , All of the deter~ency builders described ab~ve with the exception of the sodium tripolyphosphate and sodium pyrophosphate are less magnesium specific than calcium specific.

.
. , : , . .

6~i3 ~hen sodium carbo.nate is utilized as the calcium specific builder ;t is neces:sary that the precipitation of the calcium ions hy the alkali metal carbonate be enhanced by the addition of submicron calcium carbonate crystallization seeds such as are described in Belgian Patent 798,856 to Jacobson et al, published October 29, 1973. The calcium carbonates seeds are employed at a level of from about 0.1 to about 40%, prefer-ably from about 0.2% to about 20% and most preferably at from about 0.3% to about 10% by weight of the product. Further descriptions of useful methods of incorporating calcium car~
bonate crystallization seeds into detergent compositions to ~ :~
enhance the rate of calcium removal from aqueous solutions :~
are described in United States Patent 3,992,314, granted November 16, 1976, and U.S. Patent 4,035,257, granted July 12, 1977, both patents being of Cherney et al.
It is emphasized that the detergent builders listed above are only exemplary of those which may be used in the :.
present invention. Any detergency builder which rapidly removes calcium ion from solution and which is calcium speci- :
fic as defined herein is within the scope of the present invention. Preferably, the calcium specific detergency builder should remove calcium ion to a level of less than 1 grain per gallon within the first minute after introduction into a solution contaiAing 9 grains per gallon of calcium ions at a concentration of the calcium speciic detergency ~:
builder of 0.04% by weight.
~ further necessary condition to ensure that the.
calcium specific builder does not interfere with the magnesium :~
ion complexation by the silicate is that the log K[Mg +] of ~ 30 the calci~m specific builder be less than 6 and preferably : less than 5.5, more preferably less than 3.

- 39 - : .

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

i3 Thus, detergent builders such as sodium nitrilo-triacetate, trisadium 2~oxy-1,1,3-propane tricarboxylate, sodium citrate, sodium carbonate in a seeded builder sys-tem, and the aforedescribed aluminosilicates are preferred in the present invention. ~specially preferred are the aluminosilicates.
A method of incorporating the aluminosilicates of the present invention into detergent compositions (especially ; those utilizing a predominantly nonionic suxfactant system) is ~; described in US Patent 4,096,081 granted June 20, 1978. This patent describes water softening compositions comprising 5 to -;
about 50 parts o an aluminosilicate suitable in the instant invention [i.e., Naz[(AlO2)z (SiO2)j]kH2O wherein the lett~rs have the same definition as herein, a particle size diameter of from about 0.1 to about 100 microns, a calcium ion exchange capacity (anhyd. basis) of at least about 200 mg. eq. of CaCO3/
gram and generally within the range of from 300 to about 352 mg.
eq. of Ca~O3/gram, and a calcium ion exchange rate (anhyd. basis) of at least about 2 grains/gallon/minute/gram and within the range of from 2 to about 6 grains/gallon/minute/gram ], and from about 0.3 parts to about 5 parts of an agglomerating compound having a melting point of from about 30 to about 100C.
It is strenuously urged that the unique advantages which are gained in the present invention are not limited to any arbitrary mass disclosure of all known detergency builders.
It is merely sufficient that any detergency builder which is highly calcium specific as defined above will have utility in the present invention. Other calcium specific detergent builders which are considered for use in the present invention include those describea in United States Patents 3,758,419 issued to Hayden et al, September 11, 1973~ and 3,914,297 issued to Lamberti et al October 21, 1975, and 3,723,322 and 3,784,475 to Diehl, issued March 27, 1973 and ~anuary 8, 1974 respectively, as well .~

~ 40 -;i3 as 3,699,159 issued to Connor et al October 17, 1972.

`Option~al Ingredients ,~ The detergent compositions of the present invention 'l~ include all manner of detergent additives provided that these ' materials do not substantially interfere with the function of ,~ the alkali metal silicate in controlling magnesium. As a guideline, such materials may be evaluated according to the test for the magnesium insensitive surfactant or for the cal-cium specific over magnesium specific builder tests which are described above. If the particular detergent additive fails to satisfy either or both tests, it should be excluded from the composikions. ' Such materials which may be used in the present invention include brighteners, fluorescers, dyes, bleaches, bleach activators, enzymes, enzyme stabilizers, fabric soften- ~, ers, soil release agents and soil antiredeposition agents such as polymers of maleic acid, and polyethylene glycol.
Preferred components for inclusion in the present invention when the surfactant system is predominantly nonionic are antioxidants to allow the composition to be spray-dried without substantial loss of the nonionic due to combustion in the drying tower. Such antioxidants are described in United States Patent 3,403,107 issued September 24, 1968 and assigned to Union Carbide.
Alkali metal carbonates, preferably the sodium salt thereof, while not suitable as a sole calcium speclfic builder in the absence o~ a crystallization seed are highly preferred buffers to provide the necessary in use pH conditions. While the alkali metal carbonate may be added in an amount suffic-ient to adjust the pH of the wash water prior to adclition ofthe detergent, it is expedient to incorporate this material in ~ 41 -.
. the composition at a level of from about 2% to about 30%, pre-.~ ferably at from about 5% to about 20%, most preferably at from about 8% to about 15% by weight of the composition.
Certain materials which are specifically contem-plated for inclusion in the present invention despite their tendency to interfere with the control of magnesium by the :~ alkali metal silicate are described below.
: The first of the components for which the small interference should be disregarded are free fatty acids used as suds suppressors at a level o from about 0.1% to about 3%, preferably from about 0.3% to about 2.5% by weight of the composition. The second component which may interfere slightly with the ability of the alkali metal silicate to control the magnesium ions is a polymeric glassy phosphate of the formula (M2O)X(P2O5)y whereln M is an alkali metal, y has a value in :
the range of about 5 to 50, and the ratio of y:x is from about 1:1 to about 1:1.5. The glassy phosphate is used at a level ; of from about 0.1% to about 4% by weight.
The aforementioned component is useful in prevent-: 20 ing the deposition of insoluble detergent components such assurfactant precipitates and inorganic salts upon the fabrics being washed and exposed machine surfaces. Glassy phosphates and preferred methods for incorporating them into detergent compositions are discussed respectively in Canadian Patent 1,064,359 of Carson et al., granted October 16, 1979, and in United States Patent 4,113,644 dated September 12, 1978, in the ; name of Willian R. Ashcraft.

::.

:

~X' .

z pre~erred ingredient in the graIlular compositions o~ the pres~nt invention particularly when the surfactant - system is primarily nonionic are bentonite and kaolinite clays such as those described in Canadian Patent 1,039,141 to Wise o September 26, 1978.
-When the clay is a kaolinite such as "Hydrasheen 9o"*availabLe from J. M. Huber,the particle size of the clay should be less than 1 micron. Ben~onite clays may be used in a wider particle size range preferably not greater than 75u.
These clays are preferably used with the primarily non-ionic surfactant system (greater than 4% of the product) at a level o~ from about 1% to about 40% by weight of the product, prefera~ly from about 2~ to about 10% in a ratio of the nonioniG
suractant to the clay o rrom about 6:1 to about 1:2, preferably at from about 3:1 to about 1:1. Also desirable to form granular products is ~h inclusion of alkali metal sulfates, pre~erably the sodiu~ salt at a level of about 1% to 40% by weight of the product. The sulfate and clay are preferably in a 20:1 to 1:20 weight ratio.
Com~osition Utilization The detergent compositions of the present invention are generally used at a wash solution concentration OL from about 1/2 cup to about 3 cups per washing machine load. This is roughly equivalent to a usage of from about 0.05% to about 1% by weigh~
of the wash liquor. It should be noted at this point that the silicate release test previously described uses a 0.6 gram sample in 500 ml. of water to provide an in-use product concen-tration of 0.12~ by weight which is normal under U~S. usage * Trademark ~:æ

conditions. Wash temperatures under U.S. conditions will vaxy from about 20C to 40C while in Europe the upper limit is about 95C. The compositions of the present invention are intended to be used in the manner in which consumers c:ustomarily utilize such products. The process aspect of the present invention is described hereinafter.
Com~osition Pr~paration The compositions of the present invention are prepared as solids, preferably, granular products to avoid interaction of the silicate and the aluminosilicate. In the process aspect of the invention, liquid or solid components may be used as the contemplated method of use allows the separation of the various components until addition to the wash water. In such cases the calcium specific builder is added first, the silicate second as a liquid or hydrous solid silicate and the surfact-ant last. In any event the silicate must present at least about 65 ppm. SiO2 as previously defined at about one minute after its addition.
When the solid orm detergent composition has a predominately nonionic surfactant system it is preferred that clays are added to the crutcher mix prior to solidifying (prefera~ly spray-drying) the product to lessen the stickiness of the nonionic. In most cases sodium carbonate and sodium sulfate as well as the silicate will be present with the clay.
To avoid dehydration and polymerization of the silicate, thus lessening its ability to control magnesium it is preferred _ . .
that the silicate be added early to the crutcher mix and that the clay (a hygroscopic material) be added last. Pre-:

~ 44 -i3 ferably the order of addition is surfactant, silicate, sulfate, carbonate, and then the clay. Optionally the carbonate and sulfate may be interchanged in order of addition to the crutcher, however, sulfate first is preferred to reduce the need for water in the crutcher.
It is preferred that the solid form product be prepared by spray drying such as described in U.S. Patents 3,629,951 ~nd 3,629,955 to Davis et alO both issued December 28, 1971. Pre-ferred moîsture contents for these products are from about 6.5 1~ to about 15%, preferably about 7% to about 13% t and most pre-ferably from about 8~ to about 12% by weight of the spray dried portion of the product containing the alkali metal silicate.
The following are examples of the present invention and selected comparisons to products not within the scope of the invention.

.~ .
Examp'le The :following composition of the present invention is prepared-"Neodol 23-3T" (C alcohol condensed with ethylene oxide and stripped to an average ethoxylate content of 3) 9%

Sodium carbonate 10%

Sodium si~icate (input mole ratio SiO2:Na2O 2:1) 18%

Sodium sulfate 25%

Clay"Hydrasheen 90" (J. M.
Huber Co.) 5%

Polyethylene glycol (MW 6000)1%
Nal2 ~(Al;~)l2 (Si2)12]
27 ~I2O 20%
Water 8%
Minors to 100%
This product is prepared in two parts and dry blended to give the compos.ition described above. The aluminosilicate, the polyethylene glycol and a portion of the sodium sulfate are formed by spray drying a mixture of the respective components in a weight ratio of 20/1/1 on an anhydrous basis. That is if the moisture in the aluminosilicate were included in the formula the ratio would be 25/1/1. Similarily, the overall composition includes the aluminosilicate on anhydrous basis with the total product moisture reported as 8%. Each of the examples herein ~; 25 gives the alumlnosilicate on anhydrous basis.

The second part of the composition is prepared by forming ~; an aqueous slurry (30-50% water) of the remaining components less the minors and by spray drying the resultant slurry. In * Trademark **Trademark - ~6 -6~i3 . , .

$ormin~ the a~ueous slurx~ ~hich attains a temperature o~ 60C
to 90~C the components are'added thereto in the order o~ the surfactant ("Neodol 23 3T"), silicate, sulEate, carbonate and the clay last.
The composition of the present invention is then compared to a standard test product which contains:
Sodium hexadecyltriethoxysulfate 6%
Sodium dodecylbenzene sulfonate5% ~
Sodium carbonate 19% ' -Sodium silicate (SiO2:Na2O 2.4:1) 13%
Sodium sulfate 48% -, ,' Water 2%
Minors to 100%
Both products are then tested for their ability to remove `~ 15 clay soil from polyester knit fabrics in 37 C water having a hardness of 7 grains per gallon (3:1 Ca~ :rqg~). The concen-tration of each product in use is 0.2%. The product of the - present invention has an in use pH of 10.0, and gave a Hunter ~' Whiteness Unit (HWU) reading of 33 while the comparison product (pH 10.4) gave only an HWU of 21 at LSDo 95 of 2. The silicate reIease rate of the comparison product was 32 ppm while the .
, product of the present invention exhibited magnesium control due to its release of 85 ppm SiO2 as hereinbefore described. It is also noted that pH alone does not ensure magnesium control in the absence of a suitable calcium specific builder which the ,:
standard test product lacks.

~ , 5~

Example II
Th~ following products are prepared by crutching and spray drying to form detergent granules:

A

Hexadecyltriethoxy alcohol3%
(HLB 7.03 Sodium hexadecyltriethoxy 7 7 sulfate Sodium dodecylbenzene 3 3 ; 10 sulfonate Tallow alcohol sulfate 6 6 Sodium carbonate 10 10 Sodium silicate (SiO2:Na2O20 20 2.0:1) Sodium sulfate 15 18 Nal2l(Alo2)l2 (Si2)121 25 25 Moisture 7 7 Minors 4 4 Silicate release rate in ppm 73 q3 Clay removal from polyester 36 28 knit in HWU using 37C wash ~ater containing 4 grains hardness (3:1 Ca~+/Mg++) LSDo g5 2-3 Product A formulated according to the present invention shows the benefit of including a low HLB nonionic with the alkyl ether sulfate to retard the solubility of the alkyl benzene sul-fonate and the alcohol sulfate~ It is noted that Product B
actually releases SiO2 at a greater rate than Product A but that the effect in Product B is lost because of the presence of ;~ i3 the unrestrained anionic sur~actants. The pH of both products in use is 10.1. Substantially similar results are obtained when the aluminosilicate is replaced in Product A by an equivalent amount of sodium nitrilotriacetate, sodi~n citrate, or tri-sodium 2 oxy 1,1,3-propane tricarboxylate.

Example III
The following products are made by forming a slurry con-taining 30-50~ water and adaing the components. The slurry is ` then spray dried into the form of detergent granules:
- C D
Hexadecyltriethoxy alcohol2%
Tallow alcohol sulfate 9%

Sodium hexadecyltriethoxy 9% 16 alcohol sulfate Sodium carbonate 10% 10~

Nal~(Alo2)l2~sio2)l2l 25% 25%
27 ~2 Sodium silicate (SiO2:Na2015% 15 2~0:1~
Mo~sture 9% 6%
Sodium sulfate 17% 24%
; Minors to 100%

Product C of the present invention releases the silicate at 85 ppm as pre~iously defined with an in use pH of 10.1. Pro-duct D~not of the present lnvention, releases the silicate at6 ppm with a pH of 10.2.
The products are tested in 4 grain per gallon hardness (3:1 Ca /Mg ) in 37~C water at 0.12~ by weight of the product.
Clay soiled polyester knit swatches cleaned by each : ~

composition were measured for light reflectance by a Hunter Whiteness meter. Product C of the present: invention scored 40 HWU to 25 for Product D at an LSDo 95 of 1.9.
The ~oregoing test shows the value of employing a highly soluble silicate for magnesium control.
The difference in the silicate release rates is accounted ; for in the processing of the two compositions. In Product C
of the invention, the composition is prepared by adding the sul-fate to the crutcher prior to the carbonate. Product D uses the reverse order of addition. The complete order of addition ; for Product C is surfactant, silicate, sulfate, carbonate and then the aluminosilicate.
The slight rearrangement o the order of addition plus the fact ~hat Product D is dried to a lower moisture content causes the silicate in Product D to polymerize to a non-magnesium specif~c form.

..

Claims (39)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A solid form detergent composition substantially free of tripolyphosphate and pyrophosphate builders comprising:
(a) from about 4% to about 40% by weight of a magnesium insensitive surfactant system:
(b) from about 13% to about 40% by weight of an alkali metal silicate having a nominal SiO2:M2O
mole ratio of from about 1.4:1 to about 2.7:1 where M is selected from the group consisting of sodium and potassium; and (c) from about 5% to about 50% by weight of a deter-gency builder having an affinity for calcium ions over magnesium ions in aqueous medium as defined by log K[Ca++]-log K[Mg++] greater than 0.6 and log K[Mg++] is less than 6 where K is the formation constant of the builder for calcium or magnesium ions measured at from 20°C
to 25°C at a total ionic strength of from about 0.1 to about 1.0 moles/liter;
wherein the composition releases component (b) into solution so that when a 0.6 gram sample of the composition is added to 500 milliliters of distilled water at from about 25°C to about 30°C
in a 1 liter round bottom flask and the resulting aqueous solu-tion is stirred at a constant rate of from about 170 rpm to about 175 rpm by a linear blade measuring 7.62 centimeters in length, and 2.54 centimeters in height, said blade being 1.27 centimeters from the bottom of the flask, said aqueous solution will deliver a filtrate containing at least about 65 ppm SiO2 after about 60 seconds when filtered through a 47 millimeter diameter "Millipore" filter said filter having two circular 5 micron "Metricel" filter discs 47 millimeters in diameter, said discs being concentrically one atop the other in the filter, said aqueous solution being forced through said filter and the discs by a vacuum aspirator located below the filter and the discs, said composition having a pH
of from about 9.8 to about 10.4 at the intended use con-centration.

2. The composition of Claim 1 wherein the alkali metal silicate is present at from about 15% to about 30% by weight.

3. The composition of Claim 2 wherein the SiO2 in the filtrate is present at least about 80 parts per million.

4. The composition of Claim 3 wherein the alkali metal silicate has a nominal SiO2:M2O mole ratio of from about 1.5:1 to about 2.4:1 and the silicate is present at from about 16% to about 25%
by weight.

5. The composition of Claim 4 wherein component (c) is selected from the group consisting of:
(a) the water soluble salts of nitrilotriacetic acid;

(b) the water soluble salts of citric acid;
(c) the water soluble salts of 2-oxy-1,1,3-propane tri-carboxylic acid;
(d) an aluminosilicate ion exchange material of the formula:

Naz[(AlO2)z.(SiO2)j]kH2O wherein z and j are integers of at least 6; the molar ratio of z to j is in the range of from 1.0 to about 0.5 and k is an integer from about 15 to 264; said aluminosilicate ion exchange material having a particle size diameter from about 0.1 micron to about 100 microns; a calcium ion ex-change capacity of at least about 200 mg eq./g;
and a calcium ion exchange rate of at least about 2 grains/gallon/minute/gram and mixtures thereof;
(e) a mixture of alkali metal carbonates and submicron calcium carbonate particles at a level of from about 0.1% to about 40% by weight of the product; and f) mixtures of the above.

6. The detergent composition of Claim 5 wherein component (c) as defined by log K[Ca++] - log K[Mg++] is greater than 0.8

7. The composition of Claim 6 wherein the in use pH of the composition is from about 10.0 to about 10.4 and M is sodium.

8. The composition of Claim 7 wherein the detergency builder is present at from about 10% to about 40% by weight and is a compound of the formula Naz[(AlO2)z?(SiO2)j]kH2O

wherein z and j axe integers of at least 6; the molar ratio of z to j is in the range of from 1.0 to about 0.5 and k is an integer from about 15 to 264; said compound having a particle size diameter from about 0.1 micron to about 100 microns; a calcium ion ex-change capacity of at least about 200 mg eq./g; and a calcium ion exchange rate of at least about 2 grains/gallon/minute/gram and mixtures thereof.

9. The composition of Claim 8 wherein the magnesium insensi-tive surfactant is present at from about 6% to about 25% by weight and is selected from the group consisting of nonionic surfactants, alkyl ether sulfates and zwitterionic detergents and mixtures thereof.

10. The composition of Claim 9 wherein the magnesium insensi-tive surfactant is an alkali metal salt of an alkyl ether sulfate having from 10 to 20 carbon atoms in the alkyl radical condensed with from 1 to 30 moles of ethylene oxide.

11. The composition of Claim 9 wherein the magnesium insensi-tive surfactant is zwitterionic.

12. The composition of Claim 9 wherein the magnesium insensi-tive surfactant is the condensation product of an alcohol having from 10 to 20 carbon atoms in the alkyl radical and from 1 to 30 ethoxy units.

13. The detergent composition of Claim 8 additionally comprising from about 1% to about 40% by weight of a member selected from the group consisting of bentonite and kaolinite clays and mixtures thereof.

14. The composition of Claim 8 additionally comprising from about 1 to about 40% by weight of an alkali metal sulfate salt.

15. The detergent composition of Claim 8 additionally comprising from about 1 to about 40% by weight of a mixture of an alkali metal sulfate and a kaolinite clay in a respective weight ratio of from about 20:1 to about 1:20.

16. The composition of Claim 8 additionally comprising from about 0.1% to about 4% by weight of a glassy phosphate.

17. The composition of Claim 8 containing from about 2% to about 30% by weight of an alkali metal carbonate.

18. A granular detergent composition substantially free of tripolyphosphates and pyrophosphates comprising:
(a) from about 4% to about 40% by weight of a nonionic surfactant;
(b) from about 13% to about 40% by weight of an alkali metal silicate having a nominal SiO2:M2O mole ratio of from about 1.4:1 to about 2.7:1 where M is sel-ected from the group consisting of sodium and potas-sium; and (c) from about 5% to about 50% by weight of an intimate mixture comprising:
(i) a compound of the formula Na[AlO2)z?(SiO2)j]kH2O

wherein z and j are integers of at least 6; the molar ratio of z to j is in the range of from 1.0 to about 0.5 and k is an integer from about 15 to 264; said compound having a particle size diameter from about 0.1 micron to about 100 microns; a calcium ion exchange capacity of at least about 200 mg eq./g; and a calcium ion exchange rate of at least about 2 grains/gallon/
minute/gram; and (ii) from about 0.3 parts to about 3 parts of an organic agglomerating compound having a melting point of from about 30°C to 100°C;
wherein the composition releases component (b) into solution so that when a 0.6 gram sample of the composition is added to 500 milliliters of distilled water at from about 25°C to about 30°C
in a 1 liter round bottom flask and the resulting aqueous solution is stirred at a constant rate of from about 170 rpm to about 175 rpm by a linear blade measuring 7.62 centimeters in length, and 2.54 centimeters in height, said blade being 1.27 centimeters from the bottom of the flask, said aqueous solution will deliver a filtrate containing at least about 65 ppm SiO2 after about 60 sec-onds when filtered through a 47 millimeter diameter "Millipore"
filter said filter having two circular 5 micron "Metricel" filter discs 47 millimeters in diameter, said discs being concentrically one atop the other in the filter, said aqueous solution being forced through said filter and the discs by a vacuum aspirator located below the filter and the discs, said composition having a pH of from about 9.8 to about 10.4 at the intended use concen-tration.

19. The composition of Claim 18 wherein the filtrate contains at least about 80 parts per million SiO2.

20. The composition of Claim 17 wherein components (a) and (b) are present in a single granule.

21. The composition of Claim 20 containing from about 1% to about 40% of a member selected from the group consisting of the alkali metal sulfates, bentonite clays and kaolinite clays and mixtures thereof.

22. The composition of Claim 21 containing from about 2% to about 30% by weight of an alkali metal carbonate and the in use pH of the composition is from about 10.0 to 10.4 and M is sodium.

23. The composition of Claim 22 wherein the alkali metal sili-cate has a nominal SiO2:M2O mole ratio of from about 1.5:1 to about 2.4:1 and the silicate is present at from about 15% to about 30%
by weight.

24. The composition of Claim 23 wherein the nonionic sur-factant is an ethoxylated alcohol having from 10 to 20 carbon atoms in the alkyl radical condensed with from about 1 to 30 moles of ethylene oxide.

25. The composition of Claim 24 wherein the clay is a kao-linite.

26. The composition of Claim 18 additionally comprising in intimate mixture with component (c) an inorganic salt at from about 0.5 to about 3% by weight of the finished product.

27. The composition of Claim 18 additionally comprising from 0.1% to about 4% by weight of a glassy phosphate.

28, A spray-dried detergent composition substantially free of tripolyphosphates and pyrophosphates comprising:

(a) from about 4% to about 40% by weight of a water soluble salt of an alkyl ether sulfate having from 10 to 20 carbon atoms in the alkyl radical condensed with from 1 to 30 moles of ethylene oxide;
(b) from about 13% to about 40% by weight of an alkali metal silicate having a nominal SiO2:M2O mole ratio of from about 1.4:1 to about 2.7:1 where M is sel-ected from the group consisting of sodium and potas-sium; and (c) from about 5% to about 50% of a compound of the formula Naz[(AlO2)z?(SiO2)j]kH2O

wherein z and j are integers of at least 6; the molar ratio of z to j is in the range of from 1.0 to about 0.5 and k is an integer from about 15 to 264; said compound having a particle size diameter from about 0.1 micron to about 100 microns; a calcium ion ex-change capacity of at least about 200 mg eq./g; and a calcium ion exchange rate of at least about 2 grains/
gallon/minute/gram and mixtures thereof;

wherein the composition releases component (b) into solution so that when a 0.6 gram sample of the composition is added to 500 milliliters of distilled water at from about 25°C to about 30°C
in a 1 liter round bottom flask and the resulting aqueous solution is stirred at a constant rate of from about 170 rpm to about 175 rpm by a linear blade measuring 7.62 centimeters in length, and 2.54 centimeters in height, said blade being 1.27 centimeters from the bottom of the flask, said aqueous solution will deliver a filtrate containing at least about 65 ppm SiO2 after about 60 seconds when filtered through a 47 millimeter diameter "Millipore"
filter said filter having two circular 5 micron "Metricel" filter discs 47 millimeters in diameter, said discs being concentrically one atop the other in the filter, said aqueous solution being forced through said filter and the discs by a vacuum aspirator located below the filter and the discs, said composition having a pH of from about 9.8 to about 10.4 at the intended use concen-trations.

29. The composition of Claim 28 wherein the filtrate contains at least about 80 parts per million SiO2.

30. The composition of Claim 29 wherein the alkali metal sil-icate has a nominal SiO2:M2O mole ratio of from about 1.7:1 to about 2.4:1 and the silicate is present at from about 15% to about 30% by weight.

31. The composition of Claim 28 additionally comprising from about 2% to about 30% by weight of an alkali metal carbonate and the in use pH of the composition is from about 10.0 to 10.4 and M is sodium.

32. The composition of Claim 28 additionally comprising from 1% to about 40% by weight of an alkali metal sulfate.

33. The composition of Claim 28 additionally comprising from 0.1% to about 4% by weight of a glassy phosphate.

34. The composition of Claim 28 additionally comprising from about 0.1% to about 4% by weight of a nonionic surfactant having an HLB of less than 10 and mixtures thereof.

35. The composition of Claim 34 containing at from about 2% to 15% by weight of an additional anionic surfactant selected from the group consisting of alkyl sulfates and alkylbenzene sulfonates wherein the alkyl radicals contain from about 8 to about 18 car-bon atoms.

36. The composition of Claim 35 wherein the additional anionic surfactant is a mixture comprising:
(a) from about 2% to about 15% by weight of an alkyl sul-fate wherein the alkyl radical has from about 10 to 18 carbon atoms and mixtures thereof; and (b) from about 2% to about 15% by weight of an alkyl benzene sulfonate having from 9 to 15 carbon atoms in the alkyl radical and mixtures thereof.

37. The composition of Claim 35 additionally comprising from about 0.1% to about 4% by weight of a glassy phosphate.

38. A process for controlling magnesium hardness in a wash solution comprising adding from 0.05% to 1% of a detergent com-position, which is substantially free of pyrophosphate and tri-polyphosphate builders, comprising:
(a) from about 4% to about 40% by weight of a magnesium insensitive surfactant system;
(b) from about 13% to about 40% by weight of an alkali metal silicate having a nominal SiO2:M2O mole ratio of from about 1.4:1 to about 2.7:1 where M is selected from the group consisting of sodium and potassium;
and (c) from about 5% to about 50% by weight of a detergency builder having an affinity for calcium ions over magnesium ions in aqueous medium as defined by log K[Ca++] - log K[Mg++] greater than 0.6 and a log K[Mg++] of less than about 6, where K is the forma-tion constant of the builder for calcium or magnesium ions measured at from 20°C to 25°C at a total ionic strength of from about 0.1 to about 1.0 moles/liter;
wherein the composition releases component (b) into solution so that the wash solution contains at least about 65 ppm SiO2 after about 60 seconds, said wash solution having a pH of from about 9.8 to about 10.4.

39. The process of Claim 38 wherein the amount of SiO2 in the wash solution is at least about 80 ppm and the pH is from about 10.0 to about 10.4.