Note: Descriptions are shown in the official language in which they were submitted.
3~
~ he invention concerns a method of preparing
aqueous suspensions of finely divided, water-insoluble
aluminosilicates containing bound water and capable of ex-
changing cations, which are suitable for processing to wash-
ing and cleaniny agents, of the general formula
(M20)o 8-1 3 A123 (Si2)1.75-2.0 (I)
wherein M denotes an alkali metal cation. The invention con-
cerns, furthermore, the suspensions obtained according to
this method and their use particularly for the production of
washing and cleaning agents.
The compounds of the general formula I are capable
of exchanging cations with the hardness formers of waterl
that is magnesium and calcium ions. Their calcium binding
power is generally above 50 mg CaO/gm of active substance
(AS), and preferably in the range of 100 to 200 mg CaO/gm,~AS.
The calcium binding power can be determined according to the
method indicated in the examples. By "active subs-tance" (AS)
the solid obtained after drying for 1 hour at 800C. is meant.
The above-described water-insoluble alumino-
silicates are of, particular interest as ingredients of wash-
ing and cleaning agents since they are capable of partly or
completely replacing the phosphate builder substances present-
ly used today.
Aluminosilicates of the above-indicated formula
which are capable of exchanging cations are known compounds.
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They are generally synthesi~ed by preparing an aqueous mixture
consistin~ of the calculated amounts of A12O3 and SiO2 in the
indicated ratio and M20 and water by combining solutions of
the individual components. Mostly solutions of alkali metal
a:Luminate and alkali metal silicate are used as the starting
materials.
A number of various methods of preparing such
compounds within the above-outlined framework are already
known. But there is still a need for a method which provides
aluminosilicates of the above-indicated formula with a part-
icularly short reaction time and high space-time yield, which
are extremely finely-divided and have a narrow particle size
spectrum or range.
OBJECTS OF THE INVENTION
An object of the present invention is the devel-
opment of a method for the preparation of finely-divided
water-insoluble calcium-binding aluminosilicate suspensions
suitable for detergent formulations comprising 1) mixing an
aqueous alkali metal aluminate solution with an aqueous alkali
metal silicate solution in the presence of an excess of
alkali to give a silicate compound having a calcium-binding
power of at least 50 mg CaO/gm of anhydrous active substance
and having theformula, combined water not shown:
(M20)o 8 1 3 A123 (Sio2)l.75-2.o
wherein M represents an alkali metal, wherein said aqueous
solutions have a composition corresponding to the desired
A12O3 and Si02 amounts of the above formula, with at least
2.5 mols M20/mol A12O3 and not more than 80 mols H2O/mol
A12O3, rapidly with vigorous agitation, 2) agitating the
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33~
mixture vigorously while continui.ny said mixiny until the
maximum viscosity of the a~ueous mixture has been passed but
the minimum viscosity has not yet been reached, 3) then
h~omogenlzing said mi~ture at least once by recycling and
~mtil said mixing step .is completed, 4) maintaining the
homogenized aqueous suspension at an elevated temperature
until formation of at least some aluminosilicate crystals,
and 5) recovering said aluminosilicate suspensions.
A further object of the present invention is
the obtaining of finely-divided, water-insoluble, calcium-
binding aluminosilicate suspensions by the above method.
Another object of the present invention is
the developing of a process for the production of washing
agent compositions employing said finely-divided, water-
insoluble, calcium-binding aluminosilicate suspensions.
These and other objects of the invention will
become more apparent as the description thereof proceeds.
DESCRIPTION OF THE INVENTION
The subject of the invention is a method of pre-
paring the above-mentioned compounds which are called here-
after "aluminosilicates" for short, by mixing an alkali metal
aluminate dissolved in water with an alkali metal silicate
dissolved in water in the presence of excess alkali, which is
characterized in that the aqueous solutions, whose calculated
total composition regarding their A1203 and their Si02 con-
tent corresponds to the above-indicated Formula I, and par-
ticularly to the composition of the desired product, but
which contain altogether at least 2.5 mols of M20 per mol
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A1203 and at most 80 mols of water per mol A1203, as con-
t:ained in Formula I, are mixed rapidly under vigorous stir-
ring, and that the suspension obtained, optionally before the
solutions are completely combined, are further stirred
Vigorously at least until its maximum viscosity has been
passed, bu-t the minimum viscosity has not yet been reached,
after which they are recycled through a homogenizer at least
oncej but at least until the solutions are completely mixed,
and are then kept at an elevated temperature until they at
least partly crystallize. The suspensions can subsequently
be adjusted to a pH value of below 12.5 by partly washing
out the excess alkali, removing at least a part of the ad-
hering mother liquor and replacing it at least partly by
water and/or by the addition of an acid.
More particularly, the invention relates
to a method for the preparation of finely-divided
water-insoluble calcium-binding aluminosilicate suspensions
suitable for detergent formulations comprising 1) mixing an
aqueous alkali metal aluminate solution with an aqueous alkali
metal silicate solution in the presence of an excess of
alkali to give a silicate compound having a calcium-binding
power of at least 50 mg CaO/gm of anhydrous active substance
and having the formula, combined water not shown:
(M20)o 8 1 3 A123 (sio2)l.75-2-o
wherein M represents an alkali metal, wherein said aqueous
solutions have a composition corresponding to the desired
A1203 and SiO2 amounts of the above formula, with at least
2.5 mols M20/mol A1203 and not more than 80 mols ~20/mol
A1203, rapidly with vigorous agitation, 2) agitating the
mixture vigorously while continuing said mixing until the
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maximum viscosity of the aqueous mixture has been passed but
the minimum viscosity has not yet been reached, 3) then
homogenizing said mixture by recycling the same through a
separate homogenizer at least once during a period not later
than 60 seconds after said mixing step is completed,
4) maintaining the homogenized aqueous suspension at an
elevated temperature until formation of at least some alumino-
silicate crystals, and 5) recovering said aluminosilicate
suspensions.
The metal cations M in Formula I are the alkali metals,
such as lithium, potassium and preferably sodium. The
invention will be illustrated below on the basis of the sodium
aluminosilicates but the data apply correspondingly also to
the aluminosilicates of other catlons.
The composition of the aluminosilicates contained in
the Ruspensions prepared according to the invention can be
determined by elemental analysis. To this purpose, the
aluminosilicates are isolated from the suspension by washing
and adjusted to a pH value of 10 (in a suspension containing,
for example, 30% by weight of dry substance) and dried until
the adhering water is removed. The above-indicated formula
comprises both amorphous compounds and more or less crystallized
compounds of the same gross composition. The degree of
crystallization can likewise be determined in the alumino-
silicate, (isolated as described above), by comparing the
X-ray diffraction diagrams with fully crystallized samples
(maximum intensity of the X-ray diffraction lines).
The order in which the commponents are mixed can vary.
According to a preferred variant of the invention, the mixing
of the reaction solutions of sodium a]uminate or sodium
silicate, for examp]e, is so effected that some liquld,
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particularly water or at least a part of the sodium aluminate
solution, is first charged into the reaction vessel, and the
other reactants are rapidly introduced under stirring. It
is advisable to work so that a mathematical A1203 excess
exists in the reaction vessel until the solutions of the
reactants are all combined with each other. For example,
the aluminate solution is charged and the sodium silicate
solution is introduced rapidly under stirring. But the re-
verse order is likewise possible, for example, b~ diluting
first a highly concentrated sodium silicate solution with
some water.
On the other hand, it is also possible to charge
only a part of the aluminate solution, hencel for example,
10~ more, and to add the balance of the aluminate solution
during the reaction of the reaction solutions with each other.
All percentages are percent by weight, unless otherwise
! stated.
Principally, the reaction can be carried out at
any temperature but, naturally, the temperature range in
which water is liquid at normal pressure is preferred.
Mostly the temperatures are above room temperature.
By increasing the temperature, the reaction can
be accelerated, and it is preferred to mix the solution at a
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temperature between 55C and 100C, particularly between 60C
and 85OC. The aluminate solution and/or silicate solution is
preferably preheated to a temperature in the indicated range.
In general, the sodium alurninate is introduced
int-o the reaction system as a solution of sodiurn alumina-te.
The ratio of Na20 : A1203 in the sodium aluminate solution
need not necessarily correspond to the formula NaA102. Rather,
other ratios of Na20 : A1203 can also be used, provided the
synthetic mixture prepared by mixing aluminate solution with
the silicate solution has the composition in the indicated
range. The ratio Na20/A1203 can thus be higher or lower than
1 in the sodium aluminate solution, where, as a limit, the
aluminate can also be used in the form of reactive hydrate,
which then transforms the correspondingly enriched alkali in
the silicate solution into sodium aluminate during the mixing
in situ. In general, the ratio of alkali metal oxide to
A1203 in the aluminate solution is above 1.5, for example, in
the range between 2.0 and 3.5. The range between 2.0 and 3.2
is mostly preferred.
Correspondinq to the composition of the aluminate
solution which isvariable within wide limits, the composition
of the silicate solution can also be varied within wide limits.
In general, the silicate is used as water-soluble silicate,
e.g., waterglass. Provided that the presence of excess alkali
required according to the invention is ensured by the enrich-
ment of alkali in the sodium aluminate solution, a low-alkali
silicate can also be used. Again, as a limit, reac-tive silica
can be mentioned which is transformed under the reaction con-
ditions in the synthetic mixture in situ into an alkali metal
silicate. Preferably, an alkali metal silicate with a molar
ratio of M20 : SiO2 of about 1 : 2.0 to 1 : 4, particularly
1 : 2.2 to 1 : 3.8 is used.
The composition of the synthetic mixtures used
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according to the lnvention corresponds with regard to the
ratio of SiO2 : A1203 mathematically to the ahove-indicated
ratio for the suspended aluminosilicates, which is 1.75 : 1 to
2 : ].. The preferred aluminos.ilicates, particularly the pre-
ferred sodium aluminosilicates, have frequently ratios of
SiO2 : A1203 in the range of 1.8 to 1.9. The composition of
the suspended aluminosilicate corresponds with regard to
the SiO2/A1203 ratio to the composition of the synthetic
mixture; slight variations may be due to the fact that a small
amount of unreacted aluminate or silicate is also present,
in additio~ to the precipitated aluminosllicate, which is
then removed substantially by washing. These are minor
deviations, however, and they are mostly in the range of the
limit of error of the analytical determinations.
A particularly important parameter is the amount
of alkali in the synthetic mixture; it is at least 2.5 mols
of alkali metal oxide per mol of A1203. A ratio of 2.8 to
3.8, particularly 3.0 to 3.6 mols of alkali-metal oxide per
mol of A1203, is preferred. The calculated Na20 content
or alkali metal oxide content in the isolated aluminosilicate
is within the indicated range of Formula I, mostly about
0.8 to 1.2, particularly 0.9 to 1.15 mols of Na20 per mol of
A1203. Molar ratios of above 4 mols of alkali metal oxide per
mol of A1203 are generally no longer of advantage for the
purposes of the invention. Preferahly, then, the mixing and
reacting solutions should contain from 2.5 to 4 mols of alkali
metal oxide per mol of A1203.
Another important parameter is the amount of water
present. The water content of the synthetic mixture bein~
mixed should be below about 80 mols of H20 per mol of A1203.
The lower limit of the water content is that of the limit of
stirrability, that is, there must be at least so much water
present in the synthetic mixture being mixe~ that it can be
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J~
stirred in all stages of the process. This lower limit of water
in the synthetic mixture can be below 45 mols of water per mol
aluminum oxide.
In general, however, a water content on the range
between 45 and 75 mols of water per mol of A1203 is preferred.
This range is of particular advantaye when it is important
to obtain products which have, in the given composition, the
highest possible ion-exchange capacity, for example, the max-
imum binding power for the hardness-forming ions of ordinary
water. Such products are preferably highly crystalline and
have the structure of the so-called zeolite A. Depending on
the duration of the crystallation stage, other crystalline and/or
amorphous compounds, such as hydrosodalite, can be present, in
addition to zeolite. Unless it is important to obtain the
highest possible ion-exchange capacity, ratios with less than
45 mols of E120 per mol of A1203 are particularly preEerred in
the synthetic mixture to be mixed according to the invention.
~ere a particularly favorable space-time yield with extremely
finely-divided particles and absence of agglomeration are
obtained. Particularly favorable mixing ratios for the high-
est possible exchange capacity (determined as calcium-binding
power) are ohtained with molar ratios of ~120/~1203 in the range
between 45 : 1 and about 60 : 1.
When mixing the reactants with each other, a
water-clear solution is obtained first, which becomes cloudy,
however, more or less rapidly depending on the mixing temper-
ature, and gelatinous. The viscosity of the reaction mixture
being stirred first greatly increases, but then it diminishes
when the vigorous stirring is continued. The viscosity course
of the reaction mixture can be observed, for example, on the
basis of the energy consumption of the stirrer operating at a
constant speed.
When the maximum viscosity has been past, the
reaction mixture is transferred from the reaction vessel into
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a comminution device in which it is subjected to high shearing
forces and the viscosity is reduced to its minumum. Prefer-
ably, the comminution device is traversed several times, for
example, 2 to 7 times, recycling the suspension from the
comminution device to the reaction vessel where the reaction
solutions, which had not yet been completely added when the
suspensions were transferred from the reaction vessel to the
comminution device, are now added in doses. Subsequently,
the reaction mixture passes again th~ough the comminution
device.
As mentioned above, the reaction velocity, that
is, the rate of precipitation, depends on the temperature.
The viscosity maximum is thus achieved sooner or later, de-
pending on the temperature, and correspondingly, the viscosity
will drop faster or slower after the maximum has been attained,
depending on the temperature. For the removal of the reaction
mixture from the reaction vessel and the transfer to the
comminution device, it is preferable tha-t this step is com-
menced generally 1 to 120 seconds after the viscosity maximum
has been past.
If the mixing of the reactants is effected at
temperatures in the range between 55C and 100 C, particularly
between 60 C and 85 C, as it is generally preferred, the
viscosity maximum of the reaction mixture being vigorously
stirred is reached extremely fast, so that it may be advisable
under certain circumstances to control the process on the
basis of calculated time data for the individual process steps
than on the basis of the viscosity control. Thus the reactan-ts
are generally mixed with each other within a period of about
3 seconds to 5 minutes, preferably about 3 seconds to 2 minutes,
particularly within a period of about ~ to G0 seconds. The
maintenance of the suitable reaction condition is ensured if
the suspension obtained is recycled through the comminution
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devlce within about 0 to 120 seconds, preferably a~out 0 to 60
seconds after the calculated amounts of reactants required for
the formation of half the anticipated amount of the product
have been coml-ined. The treatment in the comminution device is
generally continued not later than 60 seconds after the cornplete
combination of the reactants.
The comminution devices which are used within
the framework of the invention are those devices which are
used, for example, to emulsify a liquid, which is not mis-
cible by itself with the other liquid, with the latter, or
to disperse solids with small particles size to liquids. The
phenomena which distinquish the action of the cor~inution
device according to the invention from simple stirrers are
high shearing forces, cavitation, twist and turbulence. In
particular, the comminution devices according to the invention
are devices where cavitation occurs in the treatment of
li~uids. The proce.ss is a homogenization process or homogeni-
zation with cavitation.
An example of a comminution device that can
be used according to the invention is a high-pressure homogenizer,
where the homogenization process takes place in the so-called
homogenizing valves in which the mixture of liquids which is
under a high pressure, or the suspension of silicate particles
which is under a high pressure accordinq to the invention,
expands abruptly in the aqueous medium, hence, is exposed to
a much lower èxternal pressure.
The comminution devices used are particularly
those which perrnit the treatment of suspension under conditions
under which liquids which are not miscible by themselves, like
water and benæene, are emulsified with each other, forming,
in the absence of surfactants or naturally unstable emulsi-
fiers, emulsions with a particle size be-tween 0.1 and 10~.
An example of the above-described homogenizers
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are the commercially availab~e Galllin homogenizers or high-
pressure homogeniæers.
Other comminution devices that can be used
according to the invention, as homogenizers, are the liquid
mixers, which consist of stator and rotor units. An example
is the multifrequency liquid mixexs, which consist of a
milti~stage system of stator plates and rotor disks, where
the stator plates have circular openings through the holes of
which the material to be mixed passes in an axial direction.
These openings are arranged deep in annular channels provided
symmetrically on both` sides of the stator plates. The flanks
of the channels can have specially designed indentations. The
likewise annularly arranged shearing pins of the rotor disks
run in the channels.
For most applications of ion-exchanging, the
aluminosilicates are preferred as crystalline products. Accord-
ingly, the suspension is preferably subjected to a crystalliz-
ation step, after the recycling of the suspension through a
comminution device is completed. This crystallization step
consists in keeping the suspension of the water-insoluble
aluminosilicate after the homogenization at a temperature of
between 50C ana 100C, preferably between 70C and 95C, until
the desired, radiographically-de-terminable degree of crystalliæ-
ation of the suspended aluminosilicate has been obtained. It
has been found advantageous, although by no means necessary, to
supply very lïttle or no stirring enerqy during the crystalliz-
ation of the suspension. It is of advantage if the crystalliz-
ation step is carried out continuously, supplying only so much
stirring energy to the suspension, which is thixo-tropic suspen-
sion, as is necessary to keep it fluid or conveyable.
The crystallization is also accelerated by a
temperature increase. Therefore, it is advisable to raise the
temperature at least temporarily above the temperature
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established durin~ the mixing of the aluminate and silicate
solutions, for the purpose of the crystallization. Particular-
ly suitable for the crystallization step is a method where
the temperature of the suspension is raised rapidly to 90C to
95C, for example, hy injectinq steam or by external heating,
and either keeping it at this level until the desired degree
of crystallization in the suspended aluminosilicate has been
achieved, or reducinq it again to a range of between 50C to
90C and keeping it in this range until the desired degree of
crystallization has been achieved. The mixing of the aluminate
and silicate solutions, which has preceded the crystallization
step, can be effected, for example, at 60 C to 70 C.
Within the framework of the crystallization step, the
suspensions can also be kept longer at elevated temperature
than is necessary to obtain theldesired degree of crystalliz~
ation, when it iLs desirable under certain circumstances to
influence other properties of the suspension, for example, the
particle-size distribution of the aluminosilicate particles.
The duration of the crystallization step can vary between
about 3 m~nutes and several hours. It was found surprisingly
that the above-descrihed combination of process steps yields
particularly high valuec for the calcium binding power, even
at the relatively short crystallization periods. Thus, the
duration of the crystallization step is mostly under 2 hours,
generally about 5 to 65 minutes.
After the recycling treatment in the comminution
device, or, following the crystallization step when followed,
the suspension can be cooled. After cooling, the desirable
partial neutralization is effected by washing and/or addition of
acid. For the purpose of the desirable partial neutralization,
the suspension can be freed of at least a part of its content of
excess alkali, for example, by washing. To this end the sus-
pension is freed of at least a part of the mother liquor, for
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~~
example, by centrifug~ng or filtering, after which water is
adcled and the now diluted mother liquor is separated again, if
necessary. Particularly advantageOus is the technique of dis-
plclcement washing. In qeneral, the pH value is adjusted to a
value below 12.5. But the suspensions can also be utilized at
hiyher pH values to formulate washing and cleaning agents.
Naturally the concentration of the suspension
can be influenced during the partial neutralization. Principal-
ly, the concentration can naturally be reduced to any desired
yalue by adding the required amount of water. A particular
advantage of the method accordin~ to the invention, however,
is that aluminosilicate particles are obtained which show an
unusually fa~orable suspension behavior. It is not only
possible to produce suspensions of relatively low concentra-
tions with solid contents of 5% to 20% by weight, or suspen-
sions having a medium concentration of 2~% to 30% by weight,
but also suspensions at pH values of between 7~and 11.5
with a soli~s content in the range of between 30% and about
53% by weight. At this concentration range the advantages
achieved with the method according to the invention are par-
ticularly obvious, so that, if it is intenaed to dry the sus-
pension later and excess water is thus not desired, liquid,
readily pumpable suspensions according to the invention with
solid contents of over 35%, for example, in the range oE
37% to 50%, can still be used with great advantage. However,
the term "suspension" in the sense of the invention also
includes aluminosilicate/water mixtures which are no longer
pumpable, hence mixtures which have a solids content of up
to 60% or even up to 70% by weiqht.
When speaking of "solids content", this refers
to the content of compounds o Formula I. The solids content
is de ~rmined hy filtering off the aluminosilicates of Formula
I, washing them out carefully to a pH value of the wash water
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~f~.2~
of 10, and then drying them for one hour a-t 800C to remove
the adhcring water and to determine the anhydrous active
substance (AS). A suspension according to the invention with
a solids content of 31% by weight, for example, thus contains
31% by weight of a product, isolated and dried as described
above but, naturally, products can also be present from the
production which are solid in pure form but which are removed
during the washing as water-soluble substances.
In general, the pH value is adjusted af-ter the
homogenization step and after the optional crystallization
step. This can be done, as described, by washing to pH
values below 12.5. However, it was also found advantageous
to effect the partial neutralization at least partly by
adding acid. For example, the aluminosilicate suspension
can be washed out until it has less than 5% excess alkali
with a solid concentration of 30% or more, and then be
neutralized by adding acid. Preferably, the suspension is
washed out to an alkali content of 3% or less, particularly
2% or less. The percentages relate to the total weight of the
suspension. The pH value of the suspension is generally
between about 6 and 11.5, mostly above 7 and preferably
between about 8 and 11.
The free acids which can be used for neutral-
ization are particularly the mineral acids, such as sulfuric
` acid, phosphoric acid, or hydrochloric acid. Which acid is
used specifically for the neutralization or partial neutral-
ization step depends substantially on the intendecl use of the
suspension. If the suspension is inten~ed, for example, for
the production of aluminosilicate-containing washing and clean-
3~ ing agents, sulfuric acid is generally the acid oE choice,
since it forms sodium sulfate on neutralization which does not
interfere with the washing process.
Local excessive acidification of the suspension
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should be avoided durlny the addition of acid since the
products are sensitive to free acids. This ~roblem can be
controlled, however, since local pH reductions to the ranges
where the products are dissolved or damaqed can be preven-ted
by viyorous stirring and/or slow addition.
If processing to washiny and cleaning agents is
intended, it is also possible and advisable to use a sub-
stance whose water-soluble salts have surface activity,
hence, washing activity, as the acid of neutralization.
Suitable acids for the neutralization are thus the anionic
surface-active compounds or tensides in their acid form,
particularly anionic tensides of the type of the sulfates and
sulfonates. These tensides contain in the molecule at least
one hydrophobic organic radical, mostly an aliphatic hydro-
carbon radical with 8 to 26, preferably 8 to 16 aliphatic
carbon atoms.
The tensides of the sulfate type include alkyl-
benzene sulfonates (Cg 15 alkyl~, mixtures of alkene sul-
fonates and hydroxyalkane sulfonates, as well as alkane di- ;
sulfonates, as they are obtained, for example, from mono-
olefins with terminal or non-terminal double bond by sulfon-
ation with gaseous sulfur trioxide and subsequent alkaline
or acid hydrolysis of the sulfonation products. Also suit-
able are alkane sulfonates which are obtained from alkanes
by sulfochlorination or sulfoxidation and subsequent hydrolysis
or neutralization, or by the addition of bisulfite onto
olefins. Other suitable surfactants of the sulfonate type
are the esters of ~-sulfofatty acids, e.y. the ~-sulfonic
acids from hydrogenated methyl o~ ethyl esters of the coconut
fatty acids or palm kernel fatty acids or tallow fatty acids.
Other suitable tensides of the sulfate type are the sulfuric
monoesters of primary alcohols (e.g. from coconut fatty
alcohols, tallow fatty alcohols or oleyl alcohol) and those of
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secondary alcohols. Furthermore, sulfated fatty acid alkanol-
amides, fatty acid monoglycerides, or reaction products of
1 to 4 mols of ethylene oxide with primary or secondary
fatty alcohols or alkylphenols can also be used.
Other suitab]e anionic surface-active compounds
which can be used according to the invention in their acid
form for the neutralization are the fatty acid esters or
fatty acid amides of hydroxy-or amino-carboxylic acids or
sulfonic acids, such as fatty acid sarcosides, fatty acid
glycolates, fatty acid lactates, fatty acid taurides or fatty
acid isoethionates.
The use of anionic tensides in their acid form for the
neutralization or partial neutralization of excess alkali is
also of advantage insofar as the suspensions thus prepared
have a much better suspension stability, which is of consider-
able advantage for processing, but also for storage.
Other compounds suitable for stabilizing the sus-
pensions, which can be used as free acids and thus for the
partial neutralization, naturally also in the form of their
salts, are the polymeric, especially synthetic, polycarboxylic
acids. Among these are mentioned, in particular, polyacrylic
acid and poly-~-hydroxyacrylic acid. The molecular weight of
i~ the suitable compounds of this class is generally above 20,000.
Other suitable stabilizers are the phosphonic acids,
particularly the polyphosphonic acids, such as l-hydroxyethane-l,
l-diphosphonic acid, dime-thylaminomethane diphosphonic acid,
phosphonobutane-tricarboxylic acid, methane-tri-methylenephos-
phonic acid.
The stabilization of the suspensions can also be
achieved by adding to the suspension, stabilizers which
have no acid character, such as anionic surface-active compounds,
as water-soluble salts. In this case the reduc-tion of the pll
value to values below 12.5 or particularly 11.5 must naturally
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be effected by the above-described measures. For example, the
pH value can be reduced by washing and/or by adding acid.
But the further stabilization ofthe suspensions
car~ also be effected with non-ionic surface~active compounds
or tensides, where the water-insoluble non-ionic tensides,
that is, compounds with turbidity points in water below about
50C, particularly below room temperature, are particularly
suitable. These compounds have in common that they have a tur-
bidity point in aqueous butyldiglycol solution in the range of
about 40C to 85C, particularly 55C to 85C, determined
according to DIN 53917.
Among the non-ionic surface-active compounds which
are suitable as suspension stabilizers according to the invention
are the ethoxylation products of alkanols with 16 to 18 carbon
atoms with 1 to 8 mols of ethylene oxide per mol of alcohol.
Other suitable non-ionic stabilizers are found in the .
group of compounds which have as a hydrophobic radical a long-
chained alkyl or alkenyl radical containing mostly 10 to 20, r
preferably 12 to 18 carbon atoms, which is mostly straight-
chained but which can also be branched. Unsaturated, hydro-
phobic radicals are mostly mono-unsaturated, like the frequently
encountered oleyl radical. The hydrophilic group is mostly
formed by polyoxyalkylene glycols, like ethylene glycol, propy-
lene glycol, polyoxyethy'ene glycol or glycerin radicals which
are connected with the hydrophobic radical over ester, amide,
ether or amino groups. Particularly interesting are the
ethylene oxide adducts. Among the ethylene oxide adducts with
the same turbidity point, those with the longer hydrophobic
radical of C14 to C18 are generally preferred. Suitable
stabilizers, in addition to the ethylene oxide adduc-ts onto
fatty alcohols, are the mono- and diethanolamides of carboxylic
acids, preferably fatty acids, w:ith 10 to 20, preferably 12 to 18,
and particularly 12 to 14 carbon atoms. These compounds are
-- 19 --
~ jrc:l~
derived primarily from saturated and straight-chalned carboxylic
acids. The best suitable amides can be considered as reaction
products of carboxylic acid amides withethylene oxide; here,
the number of ethylene oxide units is mostly 1 to 6, and part~
icularly 1 to 4.
Ester-like suspension stabilizers which can be
employed are the products which can be consi~ered as addition
products of ethylene oxide onto the carboxylic acids, for
example, the addition products of 1 to 10 mols of ethylene
oxide per mol of carboxylic acid. In such esters, polyalco-
~hols with more than two hydroxyl groups, such as glycerin,
can also be used as the alcohol component.
Instead of the above-mentioned ethoxylation products,
the corresponding ethoxylation products of fatty amines, hence
particularly ethoxylation products of preferably saturated
primary alkyl amines having 16 to 18 carbon atoms with 1 to 8
mols of ethylene oxide per mol of amine can also be used.
Suitable here, too, are the non-ethoxylated amines. But products
with 2 to 5 mols of ethylene oxide per mol of amine are also
20 highly suitable. Also mentioned here as stabilizing adducts
are the ethoxylated alkylphenols with a turbidity point in
water of below room temperature or a turbidity point in aqueous
.- butyldiglycol solution of below 85 C (DIN 53917). These pro-
.-~ ducts have about 5 to 8 mols of ethylene oxide per mol of alkyl-
:~ phenol, adducts with 6 to 7 mols of ethylene oxide being prefer-
red.
The specific compounds which illustrate the
.~ above-mentioned classes of non-ionic stabilizing agents are
lauric acid monoethanolamide, coconut fatty acid mono-
ethanolamide, myristic acid monoethanolamide, palmitic acid
monoethanolamide, stearic acid monoethanolamide, and oleic
acid monoethanolamide; lauric/myristic acid diethanolamide,
the diethanolamide of a fatty acid mix-ture of lauric acid and
- 20 ~
jrc~
~.
~3~3~4
myristic acid, and oleic acid diethanolamide; an ethoxylation
product of 5 mols of ethylene oxide per mol of a saturated
alcohol oramine derived from tallow taffy acid, where the
non-ethoxylated saturated tallow fatty amine can likewise be
used; the adduct of 7 mols of ethylene oxide onto nonylphenol.
The polymeric, preferably' synthetic, polyhydroxy
compounds, such as polyvinyl alcohol, can be used as compounds
suitable as stabilizers, which have neither an acid nor a
surface-active character.
lU If stabilizing additives are used according to the
invention, particularly the above-mentioned anionic or non-
ionic surface-actlve compounds, their portion in the suspensions
according to the invention can be extremely low, and the desired
stabilizing effect can still be obtained. This, too, is a
particular advantage of the invention. For example, sus-
pensions prepared according to the invention and subsequently
stabilized preferably have an aluminosilicate content of be-
tween 30% and 55% by weight, and a content of anionic and/or
non-ionic surface-active compounds in the range of 0.1% to 1%
by weight. The concentrations can naturally differ from the
indicated concentrations in one or other direction, but the
indicated range is clearly preferred, particularly the range
of 0.2~ to 0.7% by weight.
The suspensions prepared according to the invention
are highly suitable for various applications. Due to the
special type of preparation, particularly the combination of
certain mixing ratios with the above-described unusually rapid
precipitation and practically immediate processing, the sus-
pensions already have stabilities and rheological properties
which are much better than the properties of aluminosilicate
suspensions prepared in conventional manner. These suspensions
can, therefore, already be used as such, when stabilized as
described above, for example by the addition of an anionic
- 21 ~
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or non-ionic surface-active compounds, as liquid scouring
agents, with improve~ suspension stability. When used as
liquid scouring agents, additional tensides or other conven-
tional ingredients of such agents, for example, builder salts
from the group of the inorganic and organic sequest~ants for
the hardness formers of water, can optionally be added.
Another use of the suspensions according to the
invention, which is particularly important in practice, is
their processing to powdered, dry-appearing products. Accord-
ing to the invention, the suspension is subjected to atomiza-
tion where the suspension is atomized through nozzles or is
applied on rotating disks and is thus finely divided, and the
fine droplets formed by the atomization are air dried in a
hot air current. The products thus obtained are characterized
by a particularly favorable re-suspension behavior. Further-
more, the powdered products obtained according to the inven-
tion are excellently suitable for use in washing and cleaning
agent compositions. In the above-described applications, the
suspensions are preferably used in stabilized form.
A particularly important application of the sus-
pensions according to the invention is the processing of the
same to powdered washing andcleaning agents.
; The following examples are illustrative of the
practice of the invention without being limitative in any
manner:
EXAMPLES
The calcium-binding power of the aluminosilicates
produced in the following examples was determined as follows:
1 liter of an aqueous solution containing
0.59~ gm of CaC12 (=300 mg CaO/l = 30 deg. dH-German hardness)
and standardized with dilute NaOH to pH value of 10, was
mixed with 1 gm of aluminosilicate (related to AS-active
substance). The suspension was then stirred vigorously for
-22-
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~ "
2~
15 minutes at a temperature of 22 C (-~ 2 C). After filtering
off the aluminosilicate, the residual hardness x of the fil-
trate is de-termined, from which the calcium binding power is
calculated in mg CaO/gm AS according to the formula:
(30 - x) . 10. For determining the residual hardness, the
calcium content is determined by titration with EDTA (see
below).
The abbreviations used below have the following
meaning:
TA + 5 EO - an addition product of 5 mols of ethylene oxide
per mol of a substantially saturated fatty alcohol produced
by the reduction of tallow fatty acid.
ABS ~ the salt of an alkylbenzene sulfonic acid with about
11 to 13 carbon atoms in the alkyl chain, obtained by
condensation of straight-chained olefins with benzene
and sulfonation of the alkylbenzene thus obtained.
OA ~ 10 EO - an addition product of ethylene oxide onto
technical oleyl alcohol in a molar ratio of 10:1.
Waterglass - a sodium silicate (Na O : SiO calculated
2 2
ratio = 1.3.35).
CMC - the salt of carboxymethyl cellulose.
EDTA - the salt of ethylenediaminetetraacetic acid.
Perborate - a technical product of the approximate composition
NaBO2 H2O2- 3 H2
Soap - the sodium salt of a hardened tallow fatty acid.
EXAMPLE 1
l-A~
A precipitating vessel with a capacity of 60 1
was employed. This vessel was charged with 32 kg of an
aluminate solution preheated to 60 C which had the following
calculated composition (molar ratio):
Na20 : 2.68; A1203 : 1.0; ~120 : 35.55.
jrc P~-
From a storage vessel were then added within 6 to 8 seconds
under vigorous stirring with a propeller stirrer (670 rpm),
10.0 kg of sodium silicate solution, which was likewise
preheated to 60C. The sodium silicate solution has a solid
content of 35% by weight.
~ ltogether the sodium silicate solution corres-
ponded to the following composition (molar ratio):
Na20 : 0.52; SiO2 : 1.80; H20 : 14.45.
The molar ratio refers to the total calculated
amount of A1203 contained in the sodium aluminate solution,
which was assumed arbitrarily to be 1Ø The sum of the
individual data for Na20, A1203, SiO2 and H20 yields thus the
molar ratios that are present in the reaction mixture after
complete combination of the reactants, here:
Na20 : 3.2; A1203 : 1.0; SiO2 : 1.8; H20 : 50.
Immediately after the addition of the sodium
silicate solution was completed, the viscosity of the aqueous
system had already passed beyond the viscosity maximum and
was decreasing again. The aqueous system, which was
still a highly viscous gel was, in this stage, immediately trans-
ferred through a valve in the bottom of the reaction vessel,
which is now open to a homogenizer (comminution device) of
the stator-rotor type. The comminution device is a
Supraton ~ , manufacturer: Auer & Zucker, Federal Republic
of Germany.
The amount recycled was 1000 to 1500 l/h.
During the treatment in the cominution aevice, the viscosity
decreased to attain a limiting value which was clearly above
the viscosity of the aluminate or silicate solution employed
as starting materials.
While the suspension was being recycled through
the comminution device, the balance of about 4.1 kg of the
sodium silicate solution of the above-indicated composition
_24 _
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and temperature was added to the preclpitating vessel within
10 to 12 seconds. Altogether 20 seconds were re~uired for
the complete combination of the reactants. The end tempera-
ture in the reaction mixture was 70 - 72C.
~ fter a circulation for 5 minutes from the pre-
cipitatiny vessel to the comminution device to the precipi-
tatiny vessel, the suspension obtained, which could be pro-
cessed in this stage to give finished washing and cleaning
agents, was placed on a filter, and the mother liquor was
partly removed, about 40% of the total water. The filter
residue was treated on the filter with fresh water unti] the
filtrate water reached a pH of 10. The product obtained, on
the solids content,corresponded to the formula 1.1 Na20 .
1.0 A1203 . 1.8 SiO2.
l-B)
~lternately, the above suspension obtained,
after comminution, was transferred to a crystallization
vessel with a capacity of about 150 1 (a smaller vessel
could also be used) for the production of a crystalline
product. The temperature in the crystallization vessel
was immediately raised to about 90C by steam injection,
which takes about 5 minutes. After this temperature was
attained the suspension was left standing without stir-
ring for about 30 minutes at this temperature and sub-
sequently was placed on a filter. A consi~erable portion
of the mother liquor with about 1/3 of the total alkali was
removed. The amount of drained water was replaced twice
with a corresponding amount of wash water, after which a
residue on the filter of the composition lu12 Na20 .
1.0 A1203 .1.8 SiO2 . 23 H20 was obtained. This product
was stirred into some water, and the dilute suspension obtained
could be fed through pumps directly to the plant for the
production of the detergent compositions.
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3 :L2~
The product produced as described above has a
calcium-binding power of I63 mg CaO/gm AS. The p~rticle
si.ze distribution was
85% < 5~; 94~ < lO~; 99% < 20~.
The aluminosilicate of the above-described
suspension shows the following interference lines in the
X-ray diffraction diagram:
12.4; 8.6; 7.0; 4.1 (~); 3.68 (+~; 3.38 (+);
3.26 ~+); 2.96 (+); 2.73 (+); 2.60 (~).
: lO If the.aluminosilicate is less crystallized,
the intensity of these X-ray diffraction lines decreased.
The strongest interference lines are identified by a
~(+)~ All d-values were recorded with CuK radiation,
and are given in Angstroms (A).
,, 1 C)
From the residue on the filter produced as
~ described in l-B and containing crystalline sodium alumino-
,~, .
silicate, stabilized sodium aluminosilicate suspensions of
: the following compositions were obtained by mixing with
tenside-containing water:
` a) sodium aluminosilicate, 33% by weight; alkyl-
- benzene sulfonic acid (sodium-salt,Cll-Cl3 alkyl),
0.5% by weight;
b) sodium aluminosilicate, 38% by weight; ethoxyla-
tion product of 5 mols of ethylene oxide onto
l mol of a C 8 fatty alcohol, 0.5% by weight;
c) sodium aluminosilicate, 40% by weight; ethoxyla-
tion product of b), 0.25% by weight;
d) sodium aluminosilicate, 35% by weight; poly-N-
hydroxyacrylic.acid (molecul.ar weight about
lOO,OOO), 0.5% by weight;
e) sodium aluminosilicate, 38% by weight; l-hydroxy-
ethane-l,]-diphosphonic acid, 0.8% by weight.
- 26 -
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., ::
In the case of the variants d) and e), the
addition of the dispersing agent in acidic form contributes
to the partial neutralization of the suspension.
EXAMPLE 2
A suspension of crystallized sodium alumino-
silicate was prepared as described in Example l-B, but with
the difference that the sodium aluminosilicate was only
washed out until the suspension had a NaOH content of 1.15% ~`
and a solid content of 36%. The pH value of this suspension
was still above 13. 20% aqueous sulfuric acid was dosed in
,
this suspension with stirrinq in a vessel with a capacity of
150 1 until the pH value dropped to a range of 10.3 to 10.8.
The suspension thus obtained had a sodium aluminosilicate
content of 32% by weiqht, a content of sodium sul~ate of 2.~%
by weight, and a pH value of 10.3. The calcium-binding power
of the sodium aluminosilicate was 157 ma CaO/gm AS. A micro-
scopic examination of the sodium aluminosilicates showed
complete absence of undesired agglomeration of the primar~
particles of lar~er units.
EXAMPLE 3
~ Suspensions of partly to completely crystal-
;~ lized sodium aluminosilicates were prepared as described in
Example l-B, with the variations indicated below. The
sodium aluminosilicates are also characterized by their
calcium-binding power indicated in the tables below:
Formula: 2.8 Na20 . 1.0 A1203 . 1.8 SiG2 . 50 H20
Na20A123 SiO2 H20
Sodium silicate solution 0.52 1.80 14.45
Sodium aluminate solution 2.28 1.0 35.55
- 27 -
3rc: 1.1..,~.
~3~24
Precipitation at 60C, recycled for 5 minutes with
Supraton ~ , heated within 5 minutes to crystallization tem-
perature (80C and 90 C respectively) and crystallized for
another 60 minutes under stirring. Final and intermedi.ate
samples were examined, and the suspensions were washed out
after crystallization as indicated to a pH value between
9 and 11.5.
TABLE I
.~ Crystallization temperature 80C
Crystallization time ~min.) Calcium binding power(mg CaO/gm AS)
:5 . 37
166
169
Crystallization temperature 90C
,
: Crystallization time (min.) Calcium binding power(mg CaO/gm AS)
~'15 145
171
173
EXAMPLE 4
The procedure was as in Example 3, but with the
following differences:
Formula: 2.8 Na20 . 1.0 A1203 . 1.8 SiO2 . 60 H20
Na2~ A123 Si2 H2
'
Sodi.um silicate solution 0.52 1.80 14.45
Sodium aluminatè 2.28 1.0 45.55
Precipitation at 60 C, recycled for 5 minutes with
Supraton ~ , heated within 5 minutes to 85 crystallization
temperature, and c.rystallized for another 90 minutes under
stirring. Final and intermediate samples were examined.
- 28
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3~L2~
T BLR II
. .
Crystallization time (min.) Calcium binding power(mg CaO/gm AS)
107
158
_XAMPLE 5
The procedure was as in Example 3, but with the
following differences: -
Formula: 3.2 Na20 . 1.0 A1203 . 1.8 SiO2 . 44 H20
' 10 Na20 A123 Si2 H2
Sodium silicate solution 0.52 1.80 14.45
Sodium aluminate 2.68 1.0 29.55
_ . . _ _ . ... . . . . . _ _
Precipitation at 60 C, recycled for 5 minutes with
Supraton ~ , heated within 5 minutes to 90 C crystallization
temperature, and crystallized for another 60 minutes without
~- stirring. Final and intermediate samples were examined.
_ABLE III
C'rystallization time (min.) Calcium binding power(mg CaO/gm AS)
- _
124
116
112
106
;
FXAMPLE 6
The procedure was as in Example 3, but with the
following differences:
Formula: 3.2 Na20 . 1.0 A1203 . 1.8 SiO2 . 60 H20
- 29 -
1 rc:
.
z~
_2 A123 SiO2 H20
Sodium silicate solution 0.52 1.80 14.45
Sodium aluminate 2.68 1.0 45.55
Precipitation at 60C, recycled for 5 minutes
with Supraton (~) , heated within 5 minutes to crystallization
temperature (80C and 90C respectively), and crystallized
" for 60 and 90 minutes respectively under stirring. End-and
intermediate samples were examined.
_ABLE IV
Crystallization temperature 80C
Crystallization time Calcium-binding power Particle size
(min.) (mg CaO/gmAS) distribution
(portions in %)
<10 lJ <20 ~
. .
148 96 99
162 98 99
Crystallization temperature 90C
Crystallization time Calcium-binding power Particle size
- (min.) (mg CaO/amAS) disbribution
(portions in ~6)
<10 ~ <20 1
105
161 98 99
163 99 > 99
EXAMPLE 7
The procedure was as in Example 3, but with the
~ollowing differences:
Formula: 3-6 Na2 1.0 A1203. 1-8 Si2 ~ 50 ~2
Na20A123 SiO2 H20
Sodium silicate solution 0.52 1.80 1~.45
Sodium aluminate 3.08 1.0 35.55
-- 30 --
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Precipitation at 60C, recycled for 5 minutes with '~
Supraton O , heated within 5 minutes to crystallization temper-
ature (70 C) and crystallized for another 45 minutes under stir-
ring. Final and intermediate samples were examined.
TABLE
C stallization temperature 70C
Crystallization time Calcium-binding power Particle size
(min.) (mg CaO/gmAS) distribution
(portion in %)
<10 ~ <20 ~
~ _ _ _ .
; 15 165 87 97
166 95 99
167 96 99
EXAMPLE 8
The procedure was as in Example 3, but with the
following differences:
Formula: 3.6 Na20 . . 2 3 2 2
Na20 A123 Si.02 H2
Sodium silicate solution 0.52 1.80 14.45
Sodium aluminate 3.08 1.0 55.55
Precipitation at 60 C, recycled for 5 minutes with
Supraton ~ , heated within 5 minutes to crystallization temper-
ature of 90 C and crystallized for another 90 minutes under stir-
ring. Final and intermediate samples were examined.
_BLE VI
Crystallization time Calcium bindinq Particle size distri-
(min) power (mg CaO/gm bution (portion in ~)
_ AS) <5 ~ <10 ~ ~20
163
165 45 99 > 99
164 52 99
_
~ 31 -
1~3~
_XAMPLE 9
The procedure was as in Example 3, but with the
following differences:
Formula: 3.2 Na20 . 1.0 A1203 . 1.8 SiO2 . 70 H20
Na20 ~l23 SiO2 H2
Sodium silicate solution 0.52 1.80 1~.45
. Sodium aluminate 2.68 1.0 55.55
~ Precipitation temperature varied between 10 and 90C.
; Crystallization temperature at 90 - 95C.
TABLE VII
Precipitation temp. Crystallization time Calcium binding
. C (hours)power ~mg CaO/gm AS)
1.5 148
1.0 158
1.0 161
2.0 170
2.0 158
1.0 157
2.0 162
2.0 159
1.0 163
- 2.0 169
0-5 128
-
EXAMPLE 1 0
Powdered, tricklable detergents of the composition
indicated in Table VIII were produced as follows: A stock
suspension was prepared by introducing the filter residue
produced according to Example l-B and partially neutralized to
a pl~ value of 10.5, into a dispersion of a hydrogenated tallow
fatty alcohol ethoxylated with 5 mols of ethylcne oxide per mol
of alcohol. This stock suspension contained 40~ by weight
- 32 -
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1~3~
aluminosilicate and 0.5% by weight of the dispersing ayent,
based on the total weight of the suspension. This stock
suspension was pumped from a storage tank into a vessel into
which l:he other components and so much water were added suc-
cessively under stirring that a deteryent mixture (slurry)
containing ahout 45~ by weight o~ water was formed. This
slurry was passed by pumping to the atomizing nozzles arranged
at the upper end of a spray drying tower and transferred into
a fine powder by atomization and passing through hot air in
counter flow (about 260C).
Compos _ on A Co osition s
ABS 1.4% TA + 10 EO 7.0%
OA + 10 EO 8.0% TA + 5 EO (2) 2.7%
Sodium tripolyphosphate 7.8% Sodium tripolyphosphate 20.0%
Waterglass 5.4% Sodium carbonate 5.0%
CMC 0.8% Waterglass 3.0%
CMC 1.8%
Aluminosilicate(l)(AS) 36.0% Aluminosilicate(l)(AS) 18.0%
TA + 5 EO (l) 0.45% TA + 5 EO (l) 0.23%
Balance water and Na2S04 EDTA 0.5%
MgSiO3 2.5%
Perborate (3) 28.0%
Soap 2.5%
Balance water and Na2S04
(l) introduced with stock suspension
(2~ TA + 5 E0 added with the other components
(3) added after spray drying the remainder of the slurry.
Instead of the suspension being stabilized with TA
+ 5 EO, it is also possible to use in the production of a
detergent corresponding to 10 B an aluminosilicate suspension
which contains a polyacrylic acid, for example, as a stabiliz-
ing agent. Since polyacrylic acid or the neutralized salt there-
of is a sequestrant for calcium, the sodium tripolyphosphate
33 -
rc: .
~X~ 3~
portion can be reduced correspondingly. In the production
of detergents containing ABS, the ABS containing a]umino-
silicate suspension according to the invention can be used,
specifically an ABS with 11 to 13 carbon atoms in the alkyl
radical.
EXAMPLE 11
An aqueous suspension prepared according to Example l,
which contained about 40% by weight of aluminosilicate, was
atomized in a hot air current and thus dried, that is, lib-
erated of adhering water. The powdered aluminosilicate
obtained is excellently suitable as a water softener and as
a builder salt for detergents. The procedure described above
is also used with advantage with a suspension containing 40%
by weight of aluminosilicate, as described in Example l-C
a) or which corresponds to Example 1-C c). In these cases
a product is obtained which is both low-dusting and which is
also excellently suitable as water softeners and as builder
salts for detergents.
The preceding specific embodiments are illustrative
of the practice of the invention. It is to be understood,
; however, that other expedients known to those skilled in the
art or disclosed herein, may be employed without departing
from the spirit of the invention or the scope of the appended
claims.
- ~4 -
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