Note: Descriptions are shown in the official language in which they were submitted.
Case D 6695/6928 CA
GRANULAR, FREE-FLOWING DETERGENT COMPONENT
AND ME'~HOD FOR ITS PRODUCTION
This invention is directed to a detergent com- ,
ponent. More particularly, this invention is directed
to a granular, free-flowing, high powder density
detergent component and the preparation thereof.
Detergents having a relatively high powder density
of more than 600 gm/l have recently attracted greater
interest because they require less packaging volume for
the same active substance content and, hence, provide
for savings of packaging raw materials. Washing
powders having a high bulk density have long been known
in principle and include, for example, compositions of
high soda or silicate content of the type previously
obtained, for example, by simple mixture of the indivi-
dual constituents or by drying of aqueous mixtures on
lS shelves or heated rollers, extrusion, or spray
crystallization. These powders having high specific
gravity tend to cake, generally show poor dissolving
properties, and cannot be ~Ised in modern washing machi-
nes with pre-programmed washing cycles. Accordingly,
these powders have meanwhile been replaced by low spe-
cific gravity, porous powders produced by hot spray-
drying which, although dissolving relatively quickly,
are fairly voluminous for packaging and transport.
It is also known that the powder density of spray-
dried powders of the type in question can be increased
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by subsequently spraying them with liquid or molten
nonionic surfactants. Due to the favorable washing
properties of nonionic surfactants, this also increases
the detergent effect of the powders and avoids the
problem encountered in hot spray drying of smoke or-
mation in the exhaust air oE the spray towers which is
caused by entrained nonionic material. ~owever, i the
process described in German Published Application
~DE-AS) No. 10 98 132, in which the nonionic surfactant
ln is applied to spray-dried polyphosphate, is adopted,
powder densities of less -than 550 gm/l are obtained.
By use of a similar process described in U.S.
Patent Nos. 3,838,072, 3,84~,327, and 3,886,098,
whereby it is possible by spray-drying of a slurry con-
taining inorganic salts such as sodium silicate, sodiumsulfate, and sodium tripolyphosphate, as well as sulfo-
nate surfactants and soap, to produce a granular porous
carrier material. This carrier material is sub-
s,equently sprayed with a nonionic surfactant in a
mixer. In this way, it is possible to post-add up to
20% by weight o the nonionic surfactant onto the
spray-dried carrier material. In order to improve the
flowability the use of a powder additive such as e.g.
talcum, microEine silic acid or calcined clay is pro-
posed. ~ikewise, a redeposition inhibitor in powderform such as carboxymethyl cellulose, may be post-
added. The powders such obtained being loaded with
nonionic surfactants may have a powder density of more
than 500 g/l, e.g. 700 g/l, and a fluidity of, e.g. up
to 76%, based on that of dry sand, the size of the par-
~2~'~Z~g
ticles being between 3.3 mm and 0.775 mm, especiallybetween 0.83 mm and 0.15 mm.
Granular detergents having a powder density of at
least 500 gm/l, which consist of substantially spheri-
cal particles of a certain size and which have afluidity of 70~, based upon dry sand, are known from
German Published Application (DE-OS) No. 27 42 683.
These detergents, which are packed in plastic bottles,
contain from 30 to 80% of builders, from 2 to 40~ of
substantially nonionic surfactants, from 0 to 20~ of
other additives, from 0 to 50% of fillers, and from 3
to 15% of moisture. Although the products thus
described are said to lend themselves to production in
any way, Eor example, even by spray-drying or granula-
tion, the only specifically illustrated and, therefore,usable method involves a two-stage, expensive produc-
tion process in which so-called base beads having a
porous outer surface and a more or less absorbent
internal structure are first produced by spray-drying
an aqueous slurry and are then sprayed or impregnated
with the liquid or molten nonionic surfactant. Apart
from the complicated nature of the production process,
difficulties are iDvolved in producing tack-free par-
ticles containing more than 20~ by weight of liquid or
low-melting nonionic surfactants. In addition, the
products dissolve relatively poorly in cold tapwater so
that undissolved fractions can remain behind in the
powder compartments or in the liquid container of
tumbler-type washing machines.
Finally, German Published Application (DE-AS) No.
~22'~2~9
17 92 434 describes a process for the production of
granular detergents containing from 2 to 15% by weight
of anionic surfactants, from 5 to 20% by weight of
nonionic surfactants, and from 25 to 60% by weight of
tripolyphosphate by spray-drying a slurry. The tripo-
lyphosphate used for making up the slurry has to be
partly prehydra-ted, the partial prehydration being
necessary to ensure that pourable powders are obtained.
This known process gives loose powders having a powder
density of less than 550 gm/l and, where the nonionic
surfactant content is considerably in excess of 15% by
weight, only very moderate free-flow properties. Thus,
it is impossible to transfer the powder in specific
quantities from a pack or bottle into a measuring cup
because it does not flow uniformly. Instead, the
powder, xather than 10wing uniformly out of a package
tilted for pouring, piles up, even with careful
shaking, or shoots uncontrollably out of the opening,
resulting frequently in overfilling of the measuring
cup and in the spilling of relatively large quantities
of powder.
Accordingly, there has been a need to produce a
granular detergent--without any of the well-known
disadvantages--which:
tl) has a high powder density so that the packing
volume can be considerably reduced, i.e., to approxi-
mately one-hal of that of a standard spray-dried
powder;
~ 2) has a considerably increased, i.e., approxi-
mately doubled, content of wash-active substance so
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that the user obtains the same detergent power as from
a conventional spray-dried powder, despite minimal
dosage, for example, a dosage re~ed b~ half;
(3) despite the resulting high content of
nonionic surfactants, which are known to increase the
tendency of a powder to cake, flows so freely that it
pours out as if a liquid and may be accurately dispen-
sed into a measuring cup simply by tilting the supply
pack; and
(4) may be produced by a single-stage process
without any particular problems arising.
However, in these regards, the artisan has been
confronted by the following problems:
A spray-drying process carried out under standard
conditions, i.e., by the pressure atomization of
aqueous suspensions, did not appear altogether pro-
mising for solving this problem because this procedure
generally leads to expanded, i.e., porous, granules
with correspondingly low powder densities. Although
the subsequent incorporation of or impregnation with
liquiied nonionic surfactants would have enabled the
pores in the granules to be more or less filled and the
powder densit~ to be increased accordingly, the two-
state procedure involved would have been time-consuming
and expensive with regard to equipment due to the need
to use, mi~, and granulate large quantities of powder
and to thereaEter separate the coarser aggregates.
In addition, there were serious objections to the
spray-drying of powders of high surfactant content,
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particularly high nonionic surfactant content, due to
the danger of dust explosions and considerable smoke
formation in the exhaust air of the spray-drying
towers. It is for this reason that the relevant spe-
cialist and patent literature warns against processinghigh-surfactant mixtures such as these in hot spray-
drying towers, proposing instead that relatively large
amounts of nonionic surfactant be applied by spray gra
nulation to pre~ormed supporting granules. This method
of post-addition usually takes place in continuously or
discontinuously working mixing devices whereby the sup-
porting granules are subject to an intensive mechanical
treatment.
Therefore, such a treatment makes it necessary to
produce relatively solid, i.e. abxasion-resistant, gra-
nules. Granules of this type, particularly where they
contain large amounts of sodium silicate to improve
their strength, show inadequate solubility properties,
particularly in cold water, having often only a limited
capacity for taking up liquid or sticky nonionic
surfaGtants.
It is an object of this invention to provide a
novel detergent component.
It is also an object of this invention to provide
a granular, free-flowing, high powder density detergent
component and a method of preparing same.
It is a further object of the invention to provide
a granular, free-flowing detergent component which
dissolves rapidly in water and which has a powder den-
sity of from about 550 to 800 gm/1, the detergent com-
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ponent consisting essentially of synthetic,
substantially nonionic surfactants, inorganic supports,
additional organic washing aids, and water bound by
adsorption and in hydrate form, wherein the composition
is produced by spray-drying and more than 50~ by weight
of the total composition comprises droplet-like to
rodlet-like particles having an average diameter oE
from about 0.02 to 1.5 mm, an average length of from
about 0.1 to 5 mm, and an average diameter to average
length ratio of from about 1:1.2 to l:lO.
These and other objects of the invention will
become more apparent in the discussion below.
Figures l to 5 are pictures, in increasing magni-
fication, of a detergent composition according to the
invention; and
Figures 6 and 7 are pictures of a conventional
spray-dried detergent powder.
The present invention, by which the problems men-
tioned above are solved, relates to a granular, free-
flowing detergent component which dissolves rapidly inwater and which has a powder density of from about 550
to 800 gm/l, consisting essentially of synthetic,
substantially nonionic surfactants, inorganic supports,
additional organic washing aids, and water bound by
adsorption or in hydrate form. This granular detergent
composition is characterized in that it is produced by
spray-drying and in that more than 50% by weight
thereof consists of droplet-like to rodlet-like par-
ticles having an average diameter of from about 0.02
1.5 mm, an average length of from about 0.1 to 5 30 mm,
2~2~9
and an average diame~er to average length ratio of
from about 1:1.2 to 1:10. This granular detergent component
is the essential ingredient of a free-flowing granular
detergent composition being produced by admixing
further powder components. However, the free-flowing
granular detergent component as defined above may also
constitute the practically sole ingredient of the
detergent. Accordingly, the granular detergent com-
ponent of this invention is present in a granular
detergent composition in amounts ranging from 15 to
100% by weight, preferably from 50 to 95% by weight.
Suitable alkoxylated nonionic surfactants comprise
ethoxylated alcohols containing from 12 to 24, pre-
ferably from 14 to 18, carbon atoms and an average of
from 3 to 20, preferably from 4 to 16, glycol ether
groups. The hydrocarbon radicals may be saturated or
mono-unsaturated, linear, or even methyl-branched in
the 2-position (oxo radical) and derived, for example,
from naturally occurring or hydrogenated fatty com-
pounds and/or synthetic compounds. Ethoxylates derived
from cetyl, stearyl, and oleyl alcohol and mixtures
thereof have proven to be particularly suitable.
Examples thereof include tallow fatty alcohol con-
taining an average of from 4 to 8 ethylene oxide groups
(EO), tallow fatty alcohol containing an average of
from 10 to 18 EO, and oleyl alcohol containing an
average of from 6 to 12 EO, and also mixtures thereofO
Mixtures of two and more surfactants differing in
their EO-content, in which the percentage of more
highly ethoxylated alcohols predominates, have proven
~Z~ 8~
to be particularly advantageous because the tendenc~
towards smoke formation in the exhaust air tso-called
"pluming") is minimal and the detergent effect with
respect to mineral and fat-containing soil is par-
ticularly pronounced. Examples of mixtures o thistype are mixtures of
(a) tallow alcohol containing from 4 to 6 EO,
(b) tallow alcohol containing from 12 to 16 EO, and
(C) technical oleyl alcohol (i.e., mixtures of
10oleyl and stearly alcohol) containing from 6
to 12 EO,
for example, in a ratio of (a):(b) of from about 2:1 to
1:~ or in a ratio of (a):(b):(c) of from about 2:1:1 to
2:1:~ or from about 1:1:1 to 1:4:1.
15Alkoxylated alcohols of the type in whose produc-
tion first 1 to 3 mols of proplyene oxide and then ~ to
20 mols, preferably 4 to 7 mols, of ethylene oxide are
added onto the alcohol, have also proven to be advan-
tageous in the sense of a minimal tendency towards
pluming. In particular, they may replace al~ or part
of components (a) and (b) in the abvove-mentioned
mixtures.
Other suitable nonionic surfactants are those
which have a similar distribution of the ethylene gly-
col and propylene glycol ether groups and which arederived from alkyl phenols, fatty amines, fatty acid
amides, and fatty acids. The ethoxylated fatty acid
amides also include the fatty acid mono- and di-
ethanolamides and the corresponding fatty acid propano-
lamides. It is also possible to use the water-soluble
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polyethylene oxide adducts with polypropylene glycol,
ethylene diamine polypropylene glycol, and alkyl
polypropylene glycol (with from 1 to 10 carbon atoms in
the alkyl chain) containing from 20 to 250 ethylene
glycol ether groups and from 10 to 100 propylene glycol
ether groups. ~he compounds mentioned normally contain
from 1 to 5 ethylene glycol units per propylene glycol
unit. Also nonionic surfactants of the aminoxide type
may be present; likewise, aminoxides having polyglyco
lether groups in the molecule may be used.
The detergents contain from 15 to 28~ by weight
and more preferably from 17 to 25% by weight and more
preferably from 18 to 23% by weight, of ethoxylated
nonionic surfactants, based upon the total weight of
the detergent composition.
The content in the detergents of synthetic anionic
surfactants, i.e., those of the sulfonate or sulfate
type, should amount to less than about 1~l preferably
to less than about 0.5% and more preferably to about
0%, and the soap content should amount to less than
0.2%, preferably to about 0~, based upon the total
weight of the detergent composition. Advantageously
anionic surfactants are not used because it has surpri-
singly been found that even small quantities of such
additives, particularly minor additions of soap, lead
during spray~drying to expansion of the granules and
hence to a reduction in the high powder density
required and in fluidity.
Suitable inorganic supports comprise, primarily,
builder salts which are capable of binding or precipi-
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tating the salts responsible for hardness in water.
Such builder salts include polymeric phosphates, par-
ticularly sodium tripolyphosphate, and more highly
condensed polymeric phosphates, such as sodium
tetraphosphate, for example. The polymeric phosphates
may be used in admixture with their hydrolysis pro-
ducts, i.e. ortho- and pyrophosphate, although due to
the relatively high detergent and calcium binding power
of polyphosphates, suitable measures should be taken to
ensure that the polyphosphate undersoes as little
hydrolysis as possible during making up of the slurry
and during spra~-drying~
Other suitable supports are the synthetic sodium
aluminosilicates of the zeolite A type containing
bound water, i.e. being in the hydrated form. These
zeolites are capable of replacing partly or totally the
polymer phosphates, i.e. their use makes it possible
to produce zero-phosphate detergent components. The
zeolites are used in the usual hydrated, finely
crystalline form, i.e. they contain hardly any par-
ticles larger than 30 microns in size and consist to a
large extent (preferably at least 80%) of particles
less than 10 microns in size. Their calcium binding
power, which i5 determined in accordance with DE 24 12
837 Al, is in the range from 100 to 200 mg of CaO/g.
The zeolite NaA is particularly suitable, although the
zeolite NaX and mixtures of NaA and NaX may also be
used.
An essential constituent of the support are
alkali metal ~ilicates, particularly sodium silicates
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~221~8~
in which the ratio of Na2O to SiO2 amounts to fromabout 1:1~5 to 1:3.5, preferably from about 1:2 to
1:2.5. Mixtures of silicates differing in their alkali
metal content, Eor example, a 1:2 mixture or 1:2.5-3
mixture of Na2O and SiO2, may also be used, although
advantageously in the interests of a high powder den-
sity and percentage of silicates having a relatively
high Na2O content should best predominate.
Other suita~le supports, which may be used in
admixture with the compounds mentioned above, are
sodium carbonate, sodium sulfate, and magnesium sili-
cate. Compounds having a high adsorption capacity,
such as finely particulate silicas, clays, or ben-
tonites, may also be present.
The percentage of inorganic support amounts
overall to from about 40 to 80~ by weight, preferably
from about 45 to 70~ by weight, based upon the weight
of anhydrous or nonhydrated constituents. The percen-
tage content in the detergent component of sodium tri-
polyphosphate (including the hydrolysis products)
amounts to from about 0 to 60% by weight, preferably
from about lS to 50% by weight and more preferably from
about 20 to ~0~ by weight, and the percentage of alkali
metal silicates amounts to from about ~ to 20% by
weight, preferably from about 6 to 15% by weight and
more preferably from àbout 6.5 to 12% by weight, based
upon the total weight of the detergent component. The
sodium aluminosilicate is present in quantities of from
about 0 to 40~ by weight, preferably from about 3 to
30% by weight and more preferably from about 5 to 20%
~2;~Z~9
by weight, based upon the total weight of the detergent
component. The same applies to the case where the per-
centage sodium aluminosilicate content is increased to
beyond the indicated maximum of 40% by weight . In
these cases the zeolite content may amount to up to
65% by weight.
Although the percentage polyphosphate content of
the detergent may be of the same order as that of con-
ventional heavy-duty detergents, the tendency towards
phosphate reduction is fully acknowledged in the
invention. First, the detergents according to the
invention are used in quantities very much smaller than
for conventional, i.e., low specific gravity, washing
powders, and, second, the phosphate content may be con-
siderably reduced, i.e., to 10% by weight, in favor ofthe percentage aluminosilicate content.
The detergent component of this invention may also
contain--as additional organic washing aids--so-called
co-builders--which, even in small quantities, are
capable of considerably enhancing the effect of the
polyphosphates and sodium aluminosilicates. Suitable
co-builders are, in particular, polyphosphonic acids
and their alkali metal salts. Suitable polyphosphonic
acids include l-hydroxyethane-l,l-diphosphonic acid,
amino-tri-~methylene phosphonic acid), ethylene diamine
tetra-(methylene phosphonic acid) and their higher
homologs, such as, for example, diethylene triamine
tetra-(methylene phosphonic acid). Other suitable co-
builders comprise complexing aminopolycarboxylic acids,
including in particular alkali metal salts of nitri-
~L~2Z~28~
lotriacetic acid and ethylenediaminetetraacetic acid.The salts of diethylene triamine pentaacetic acid and
the higher homologs of the aminopolycarboxylic acids
mentioned are also suitable co-builders. The polyacids
mentioned are preferably used in the form of their
sodium salts.
Other suitable co-builders include polymeric car-
boxylic acids and their salts having a molecular weight
of at least 350 in the form of the water-soluble sodium
or potassium salts, such as polyacrylic acid, poly-
methacrylic acid, poly ~-hydroxyacrylic acid, polyma-
leic acid, polyitaconic acid, polymesaconic acid,
polybutene tricarboxylic acid, and also copolymers of
the corresponding monomeric carboxylic acids with one
another or with ethylenically unsaturated compounds,
such as ethylene, propylene, isobutylene, vinyl methyl
ether, or furan. The copolymer of maleic acid and
acrylic acid in a ratio of from about 5:1 to 1:5 is
mentioned as an example. Small quanitites of these co-
builders are to be understood to mean amounts of from0.5 to 1~ by weight, preferably of from 1 to ~% by
weight, calculated on the total amount of the detergent
component.
Additional organic detergent ingredients which may
be present in the spray-dried powder component include
redeposition inhibitors, optical brighteners, and addi-
tives which improve the viscosity behavior of the
slurry, for example, alkali metal salts of toluene,
cumene, or xylene sulfonic acid, as well as, optimally,
thickening agents such as polymers, e.g. of the Car-
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bopol~ type. Suitable redeposition inhibitors arel in
particular, carboxymethyl cellulose, methyl cellulose,
water-soluble polyesters and polyamides of polybasic
carboxylic acids and glycols or diamines containing
Eree carboxyl groups, betaine groups or sulfobetaine
groups capable of salt formation, and also colloidally
water-soluble polymers and copolymers of vinyl alcohol,
vinyl pyrrolidone, acrylamide, and acrylonitrile.
These organic detergent auxiliaries may be present in
quantities of from about 0.5 to 10~ by weight, based
upon the total weight of the detergent component.
Suitable optical brighteners are the alkali metal
salts of 4,4-bis-(2"~anilino-4"-morpholino-1,3,5-
triazinyl-6"-amino)-stilbene-2,2-disulfonic acid or
compounds of similar structure which, instead of the
morpholino group, contain a diethanolamino group, a
methylamino group, or a ~-methoxyethylamino group.
Other suitable optical brighteners include brighteners
of the substituted diphenyl styryl type, for e~ample,
the alkali metal salts of 4,4-bis-(2-sulfostyryl)-
diphenyl, 4,4-bis (4-chloro-3-sulfostyryl)-diphenyl,
and 4-(4-chlorostyryl)-4-(2-sulfostyryl)-diphenyl.
The detergent component of the invention normally
has a water content of from about 8 to 20% by weight,
preferably from about 10 to 16% by weight, which is to
be understood to mean both the water bound by adsorp-
tion and water of hydration.
The amount of water being bound in the hydrated
sodium aluminosilicate is in the region of about 20% by
weight related ko the kokal amount of hydrated sodium
~2~2~9
aluminosilicate, i.e. it is the degree of hydration of
the sodium aluminosilicate being in equilibrium with
its surroundings. This fraction must be taken into
account in calculating the quantity of water.
~asically, the quantity of water present should be
measured in such a way that satisfactorily Eree-flowing
products are obtained. The preferred water content
amounts to from about 10 to 16% by weight, based upon
the total weight of the detergent component.
The grain structure of the powder component
according to the invention is characteristic and, in
this respect, differs considerably from that of known
and commercially available detergents. The powder com-
ponent of the invention consists predominately, i.e.,
to an extent of from 65 to 100~ by weight, based upon
the total weight of the detergent component, of droplet
to rodl~t-like particles which, for an average
diameter of from about 0.02 to 1.5 mm, preferably from
about 0.05 to 1 mm, and an average length o from about
0.1 to 5 mm~ preferably from about 0.3 to 3 mm, have a
diameter-to-length ratio of from about 1:1.2 to 1:10,
preferably from about 1:1.4 to 1:8, with a pronounced
maximum at about 1~ to 1:5. The particles are com-
pact, i.e., they have a dense, non-sponge-like or non-
foam-like structure. Their surface is uninterrupted,
i.e,. non-porous and appears smooth when viewed
macroscopically, i.e. with the naked eye. Examination
of their surface under a microscope reveals a texture
which may be described as grained to striated and is
remlniscent of solidified, non-porous slag.
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Figures 1 to 5 show, with increasing magnifica-
tion, characteristic particles of the detergent com-
ponent according to the invention. The end of one such
particle at a fracture is shown in Figure 5. This
example shows that the structure can continue inside
the particles.
Figures 6 and 7 which, for comparison, illustrate
a conventional spray-dried powder of low powder den-
sity, show agglomerated particles of irregular,
approximately spherical form and with a substantially
smooth surface. As can be seen from the cross-section
of a particle shown in Figure 7, the interior of the
individual particles is expanded and shows a porous
sponge-like or foam-like structure characteristic of
such spray-dried powders. Powder structures such as
these are not the subject of the present invention.
The language "to an extent of more than 50~ by
weight" or "preferably lto an extent of] more than 65
to 100% by weight" of droplet-like or rodlet-like par-
ticles means that the detergents may also be made up toa smaller extent of particles having a different shape,
i.e., two or more droplet-like to rodlet-like particles
are cemented to form irregular agglomerates, or small
numbers of approximately spherical particles are formed
during production or elongate particles brealc up into
short fragments during further processing or during
transport. Additional powder constituents which have
not been spray-dried and which have a different powder
spectruml for example, bleaches, bleach activators,
enzymes, and foam inhihitors, may also be added to the
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detergent component according to the invention.
Detergent premixes, so-called compounds, being
made up of sulfonate and/or sulfate surfactants and,
optionally, also of soaps, together with carriers such
as sodium tripolyphosphate, zeolite A, and waterglass,
and being prepared by usual spray-drying or granulating
methods, also belong to this type of additional powder
products. Likewise, textile softening granulates con-
taining quaternary ammonium compounds as active ingre-
dients together with soluble or insoluble carriers anddispersion inhibitors, or other textile softening gra-
nulates formed with laminated silicates and long-
chained tertiary amines, may be used as additives.
These additional powder constituents may be made
up of differently shaped particles, for example, of
more or less spherical prills or granulates. They
should be of such a structure and used in such a quan-
tity that they do not reduce the powder density and
free-flow properties of the detergents to any sighifi-
cant extent, if at all. This powder density amounts tofrom about S50 to 800 gm/l, preferably from about 600
to 750 gm/l and more preferably~ from about 620 to 720
gm/l.
Although the detergent components of the invention
are only suitable to a limited extent for the deter-
mination of particle size distribution by sieve analy-
sis on account of their characteristic rodlet-like
~owder structure 9 it is possible to determine the grain
spectrum by that method. Results show that the grain
spectrum is relatively narrow, i.e., more than about
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12;~S~
70~ by weight and, in most cases, even from about 80 to
90% by weight of the powder lies within a meshwidth
range of from abGut 0.2 to 0O8 mm. With a conventional
spray-dried powder oE low powder density, generally no
more than from 50 to 70% by weight falls within this
grain size range. The dust content of the detergent
component and also the percentage of oversi~e grain are
also correspondingly low so that the spray-dried powder
does not have to be subsequently sieved nor do any dust
binding agents have to be subsequently addedn
The detergent components according to the inven-
tion are free-flowing and are superior in their
fluidity to the known spray-dried hollow-bead powders
of low specitic gravity. Their fluidity is comparable
with that of dry sand and, according to the results of
a test described in the examples below, amounts to from
about 75 to 95~ of that of a dry sand having a certain
grain specification. This high fluidity, which is far
superior to the fluidity of substantially spherical
spray-dried powders of comparable grain size, is extre-
mely surprising because, with increasing deviation from
spherical dimensions, the powder particles would nor-
mally have been expected to lose their free-rolling
property.
It is also surprising that despite the high con-
tent of nonionic, tacky surfactants and the absence of
microcavities capable of taking up these surfactants,
the particles do not show any tendency to agglomerate
or to give off these tacky constituents. In contrast
to powders having an equally high content of nonionic
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surfactant, in whose case the nonionic surfactant is
applied to a~sorbent spray-dried granulates produced
beforehand, even the nonionic surfactant cannot be
removed again by squeezing between filter papers.
Accordingly, the detergents according to the invention
also do not cause standard, uncoated cardboard packs to
become greasy or to "leak."
Another aspect of the invention is the ab`ility of
the powder to contract. It is unavoidable in the auto-
matic packaging of a detergent that the detergentshould initially occupy a slightly greater volume which
decreases only slightly, even in the event of brie
shaking. During the transportation of the packages to
the consumer, a gradual contraction or settling takes
place. The consumer notices this reduction in volume
upon opening the package and frequently comes to the
conclusion that he or she has been sold an incompletely
filled package. With conventional hollow-bead powders
of low specific gravity, this reduction in volume
amounts to from about 10 to 15%. Predominantly spheri-
cal granulates obtained, for example, by applying
nonionic surfactant to presprayed support grains show
reductions in volume on the order o~ about 10%. In the
case of dry sand, this value is about ~%. The
detergent compositions according to the invention
exceed even these values, i.e., in their case the
reductions in volume are usually below ~0~ and, in
favorable cases, reach 5~. Their high volume stability
coupled with their outstanding fluidity makes the
detergents according to the invention easier to
-20-
~;~2~Z89
dispense in exact reproducible quantities both at the
packaging stage and in practical application.
In some cases it is of advantage to have the gra-
nulates of the invention covered with a finely divided
solid as a fluidity improving agent. This solid
material may be soluble or insoluble in water, and may
be present in amounts of Erom 0.01 to 3~ by weight of
the granular spray-dried product.
This cover further improves the fluidity of the
product and also imparts weather-resisting properties
to the product. The finely divided synthetic zeolites
of the type NaA, and NaX respectively, have been found
to be of special value as such coating agent. The
positive effect of these zeolites is not confined to
the improvement of fluidity but also increases the
builder amount and, therefore, the washing power of the
product. Further, microfine silica, especially pyroge-
neous silica, may be used as fluidity improving agent.
The amount of the fluidity improving agent is pre-
ferably 0.1 to 2% by weight in the case of the zeoli-
tes, and, in the case of the microfine silica,
preferably 0.05 to 0.5% by weight, with respect to the
granular spray-dried product.
Likewise, other powder materials such as finel~
divided sodium tripolyphosphate, sodium sulfate, magne-
sium silicate, talcum, bentonite, and organic polymers
like carboxymethyl cellulose and urea resins, may also
be used, provided the particle size of these powders is
below 0.1 mm, e.g. in the range of from 0.001 to 0.08
mm. Coarser powder qualities such as used in detergent
~Z2~ 39
and cleaning composition~ have to be pulverized pre-
viously. Coating agents of this latter type are pre-
ferably used in amounts of from 1 to 3~ by weight.
~he present invention also relates to a process
for producing the detergent component according to the
invention, wherein a suspension of the constituents
containing in all from about 35 to 55% by weight of
water (including the water bound by adsorption and the
water of hydration) is sprayed by means of nozzles into
a drying tower under a pressure measured at the nozzle
entrance of from about 16 to 30 bars and for a nozzle
orifice diameter of from about 3 to 5.5 mm, the ratio
of the pressure at the nozle entrance to the diameter
of the nozzle orifice amounting to from about 3 to
9 bars/mm~
Preferably, the pressure at the nozzle entrance is
in the range from about 18 to 28 bars, more preferably
in the range from about 19 to 25 bars, the diameter of
the noz~le orifice amounts to from about 3.5 to 5 mm,
and the ratio of the pressure to the diameter of the
nozzle orifice is from about 4 to 6 bars/mm, more
preferably from about 4.5 to 5.5 bars/mm. The
maintenance of these parameters is crucial to the grain
properties of the detergent component of the invention.
Any distinct overstepping of these limits in either
direction, particularly in the event of an increase in
pressure or reduction in orifice diameter, results in
the formation of more or less irregular to spherical
agglomerates with a Eoam-like structure which in turn
leads to a ]ower powder density and poorer flow properties.
-22-
g
An excessive reduction in pressure can lead to defec-
tive atomization and to the formation of crusts around
the nozzle orifice. Inadequate powder properties are
also obtained where the nozzles used have excessively
large orifices, i.e. orifices with diameters far larger
than 5 ~m. It has proven to be particularly favorable,
for example, to apply a pressure of from about 19 to 25
bars for a nozzle orifice diameter of from about 3.5 to
4.5 mm. It is advantageous to use nozzles which exert
a spin effect on the material to be sprayed.
The spray-drying installation is operated with hot
air or hot combustion gases which are preferably guided
in countercurrent to the material to be spray-dried.
The drying gas is best introduced tangentially into the
tower, which produces a certain spin effect. The entry
temperature of the drying gas should not exceed 250C
and is preferably in the range from about 180 to
240C, more preEerably in the range from about 190 to
220C
If hotter drying gases are used, it is necessary
for the surfactants to be predominantly highly ethoxy-
lated or mixed-alkoxylated surfacatnts to suppress
pluming in the exhaust air. If the surfactant mixtures
of low and highly ethoxylated compounds described in
the foregoing as preferred are used~ no pluming occurs
providing the entry temperature of the drying gas is
kept in the range rom about 190 to 220C, in addition
to which the measured emission values are far below the
legal maximum.
The temperature of the drying gases upon leaving
~2~2~Z~3
the drying tower is generally of the order of 90C +
15C and is preferably in the range from about 80 to
95C. The upper value may be subject to certain fluc-
tuations, dependent upon, inter alia, the outside tem-
peratures, and should he selected in such a way thatthe temperature in the ollowing dust separators does
not fall below the dew point.
The aqueous detergent preparation to be sprayed
contains a total of from about 42 to 55~ by wei~ht,
preferably from 44 to 52% by weight and more par-
ticularly from about ~6 to 50% by weight of water,
including the water bound by adsorption and the water
of hydration. Higher water contents are inappropriate
because they increase the degree of hydrolysis of the
tripolyphosphate, raise energy consumption, and lead to
a reduction in powder density. Lower contents can lead
to a drastic increase in the viscosity of the slurry
and thus necessitate special measures, such as
increasing mixing and transporting capacity or adding
viscosity-reducing agents, such as toluene, xylene, or
cumene sulfonate.
Although the order adopted in preparing the slurry
is not critical, processing can be made easier by main-
taining certain process conditions. In addition, it is
advisable to keep the mixing and residence times as
short as possible due to the considerable increase in
viscosity in the slurry. It is advisable initially to
introduce the liquid products, i.e., the molten
nonionic surfactants and the constituents already present
in aqueous solution or suspension, for example, the
-24-
~;22~2~9
aluminosilicate in the for~ of a filter-moist paste,
and -- optionally -- additional water and then to add
the anhydrous constituents, particularly the anhydrous
or optionally partly hydrated tripolyphosphate, with
S vigorous stirring. If anhydrous, slowly hydrating
sodium tripolyphosphate of the II-type is used, a
drastic increase in viscosity and extensive hydrolysis
to lower phosphates are avoided, although this might
involve a slight reduction in the fluidity of the
spray-dried product. Tripolyphosphate which hydrates
more quickly, for example, a tripolyphosphate con
taining fairly high proportions of the I-type or partly
prehydrated tripolyphosphate, leads to higher slurry
viscosities. It i8 an advantage of the process that
there is no need to use prehydrated polyphosphate.
In preparing the slurry it is a particularly pre-
ferred feature to use anhydrous ~odium tripolyphosphate
having a content of 30 to 50%, especially 35 to 45~ of
the modification of the I-type. It is known that tri-
polyphosphate of the I-type is characterized by an
accelerated speed of hydration. This accelerated speed
of hydration, however, may cause problems with the
handling of the slurry. By the process of hydration
free water is withdrawn from the slurry resulting in a
strong viscosity increase. A too high slurry visco-
sity, however, not only complicates the handling, i.e.
the mixing, transporting, and spraying of the slurry,
but also leads to lower bulk densities of the resulting
powder.
In order to assure a sufficient fluidity of the
-25-
~LZZ~2891
slurry and to obtain spray-dried products with
favorable po~der properties, it turned out to be
suitable to adjust the slurry viscosity to values in
the range of from 2000 to ma~imally 150nO mPa.s, pre-
ferably from 5000 to 12000 mPa.s, and particularly from
6000 to 10000 mPa.s. In adjusting the viscosity,
heating of the slurry to temperatures of above 85C,
e.g. to 86C to 102C, before adding the solids, espe-
cially before adding the tripolyphosphate, is pre-
ferred. The heating is suitably done by introducing
steam, particularly superheated steam. At the given
temperatures, the hydration of the tripolyphosphate in
the slurry is to a large extent stopped, or at least
so delayed that no unwanted viscosity increase occurs
during the handling period. Moreover, the use of
strong shearing forces such as intensive mixing with a
stirrer or keeping the slurry in circulation with pum-
ping devices, helps to maintain the fluidity of the
slurry. The use of strong shearing forces prevents the
formation of structured viscosities. In the case of
such slurries that do not contain any sodium tripoly-
phosphate, the preferred viscosity ranges are adjusted
through the use of viscosity regulating agents.
The product leaving the spray-tower usually has a
temperature of 65 to 80C. It has been found that
under unfavorable conditions, which may occur during a
continuous long-term production, deviations with
respect to certain product properties such as density
and fluidity of the grains happen~. Seasonal changes in
climate, e.g., may be of influence. In this respect,
-26-
lZ~Z8~
it has been found that during the processing of the
spray-dried powder, particularly in the cooling phase
after leaving the spray-tower, high air temperatures
are unfavorable. When the spray-dried product still
S warm after leaving the spray-tower is stored in silos
over a longer period, a migration of the nonionic sur-
factants to the surface of the grains may occur
resulting in a decrease of the fluidity but without
leading to caking.
This disadvantage can be overcome by subsequent
powdering (coating) of the grains as described above.
However, it is advantageous to cool the product aEter
it has left the spray-tower without delay, i.e. within
less than 5 minutes, preferably within 2 minutes, to
temperatures below 35C, e.g. to 20C to 30C. This,
for example, can be done with a pneumatic conveying
equipment operating with sufficiently cold air, i.e.
having a temperature of less than 30C. If, during the
hot season, the temperature of the cooling air is not
sufficient to cool the product fast enough, subsequent
powdering is advisable.
The coating, respectively powdering of the spray-
dried grains may take place before or aEter or, pre-
ferably, during admi~ing of other powder compounds.
~hese additional powder components encompass peroxy
compounds, bleach activators (so-called peracid
precursors), enzyme granulates, foam inhibitors and
foam boosters, as well as so-called surfactant or soft-
ener compounds, i.e. powder products consisting of
carrier substances and surfactants, particularly
-27-
2~39
anionic surfactants, or of carrier substances and tex-
tile softeners, respectively. By the simultaneous
admixing of the fluidity improving agent and the addi-
tional powder components a further mixing step can be
avoided. Water insoluble coating agents such as zeoli-
tes and silicic acid aerogels may be applied before the
termination of the spray-drying, i.e., by injecting
these agents in the lower part of the spray tower onto
the already formed component grains. The injecting of
the coating agent may be done by dosing it into the
drying air.
The powdering of the spray-dried grains also leads
to a partial smoothing of the grain surface thus
further improving the fluidity of such grains.
Moreover, by this measure, the bulk density of the
powder can be somewhat increased, obviously the coating
resulting in a denser packing of the grains.
Thereore, the invention encompasses also a pro-
cess for the after-treatment of the granular, spray-
dried powder component in a mixing device by admixing0.01 to 3~ by weight of the finely divided solid of the
above definition.
As for the rest, it is possible to use any of the
apparatus and process aids which are known to those
skilled in the art of modern spray-drying technology.
Other constituents in powder or granular form may
be added to and mixed with the spray-dried detergents.
Such constituents include substances which are
unstable or which would completely or partly lose
their specific effect under spray-drying conditions.
-28-
~;Z2~3L28~
Additives of this type, which are added to the powder
after spray-drying, include enzymes from the class of
proteases, lipases, and amylases or mixtures thereof.
Enzymes obtained from bacterial strains or fungi, such
as Bacillus subtilis, Bacillus licheniformis and
Streptomyces griseus, are particularly suitable. In
general, fragrances and anti-foaming agents, such as
silicones or paraffin hydrocarbons, are also sub-
sequently added to the spray-dried powder component to
avoid losses of activity.
The bleaching component may be any of the
perhydrates and per compounds normally used in
detergents and bleaches. Preferred perhydrates are
sodium perborate, which may be used in tetrahydrate or
even monohydrate form, the perhydrates of sodium car-
bonate (sodium percarbonate), sodium pyrophosphate
(perpyrophosphate), sodium silicate (persilicate), and
urea. These perhydrates may be used together with
bleach activators.
The preferred bleach component is sodium perborate
tetrahydrate used in conjunction with bleach activa-
tors. The bleach activators include, in particular, N-
acyl compounds. Examples o~ suitable N-acyl compounds
comprise polyacylated alkylene diamines, such as
tetraacetyl methylene diamine, tetraacetyl ethylene
diamine, and also acylated glycolurils, such as
tetraacetyl glycoluril. Other examples include
N-alkyl-N-sul~onyl carbonamides, N-acyl hydantoins, and
N-acylated cyclic triazoles, urazoles, diketopiperazi-
nes, sulfuryl amides, cyanurates, and imidazolines. In
-29-
: ,
~2;~
addition to carboxylic acid anhydrides, suitable O-acyl
compounds are, in particular, acylated sugars, such as
glucose pentaacetate. Preferred bleach activators are
tetraacetyl ethylene diamine and glucose pentaacetate.
To avoid interactions with the other constituents
of the detergent during storage of the powder-orm mix-
tures, the enzymes, silicone anti-foaming agents, and
bleach activators may be granulated and/or coated in
known manner with substances that are soluble in water
or dispersible in washing liquors. Suitable granu-
lating agents are any of the usual salts which are
capable of taking up water of hydration. Suitable
coating substances are water-soluble polymers, such as
polyethylene glycol, cellulose ethers, cellulose
esters, water-soluble starch ethers, and starch esters,
and also nonionic surfactants of the alkoxylated alco-
hol, alkyl phenol, fatty acid, and fatty acid amide type.
The detergent component produced according to the
invention is only slightly foam-active, it can be used,
therefore, in automatic washing machines without any
problems. In cases where stronger foaming is desired
in the use of the detergent, particularly in the laun-
dering of delicate textiles, or in laundering at low
temperatures which is mostly done by hand, foam-active
surfactants and mixtures thereof, preferably in com-
pound form, are post-added. This includes known
anionic surfactants of the sulfonate and/or sulfate
type and zwitterionic surfactants. Such an admixture
may lead to further increase of detergency. This
admixture may amount up to 10% by weight, preferably
-30-
~Z2:~2~39
0.2 to 8% by weight, with respect to the resulting
mixture. Anionic surEactants which can be used are for
example the alkyl benzenesulfonates, e.g. n-dodecyl-
benzenesulfonate, olefinsulfonates, alkane-sulfonates,
primary or secondary alkylsulfates, ~-sulfofatty acid
esters as well as the sulfates of ethoxylated or pro-
poxylated higher molecular weight alkanols, monoalky-
lated or dialkylated sulfosuccinates, sulfuric acid
esters of fatty acid partial glycerides, and fatty acid
esters of 1,2-dihydroxypropane sulfonic acid. Useful
zwitterionic surfactants are the alkylbetaines, and
particularly the alkylsulfobetaines, e.g. the compounds
3-(N,N-dimethyl-N-alkylammonium)-propane-l-sulfonate,
and 3-t~,N-dimethyl-N-alkylammonium)-2-hydroxypropane-
l-sulfonate. Out of these surfactants, the alkylben-
zene sulfonates, olefinsulfonates, alkane-sulfonates,
sulfates of fatty alkanols, and alpha-sulfofattyacid
esters are preferred because of their foam-boosting and
simultaneous detergency increasing effects. If foam-
boosting is the main goal it is advisable to use thesulfates of ethoxylated fatty alkanols haviny in par-
ticular 1 to 3 glycolether units, and the
alkylsulfobetaines.
The anionic surfactants and their mixture are pre-
ferably used in form of the sodium or potassium salts,
or as salts of organic bases such as mono-, di- or
triethanolamines. If the above anionic and zwitter-
ionic surfactants have an aliphatic hydrocarbon radical
this is preferably straight-chained having 8 to 20,
3~ particularly 12 to 18 carbon atoms. In compounds with
-31-
Z8g
an aliphatic hydrocarbon radical the alkyl chains have
preferably an average of 6 to 16, in particular 8 to 14
carbon atoms.
These optionally used anionic and zwitterionic
surfactants arè preferably used in granulated form.
Granulating agents respectively carrier substances are
usual inorganic salts such as sodium sulfate, sodium
carbonate, phosphates and zeolites and mixtures
thereof.
Textile softening additives are usually consisting
of granulates containing a quaternary ammonium compound
(QAC), e.g. distearyl dimethyl ammonium chloride, a
carrier and an additive delaying the dispersion in the
wash liquor. A typical granulate consists, e.g., of
86% by weight of QAC, 10% by weight of pyrogenic sili-
cic acid, and 4~ by weight of silicon oil (polydimethyl-
siloxane activated with pyrogenic silicic acid).
Another granulate has, e.g., the composition of 30% by
weight of QAC, 20~ by weight of sodium tripoly-
phosphate, 20% by weight of zeolite ~aA, 15% byweight of waterglass, and 2~ by weight of silicon oil,
the remainder being water.
With regard to granulation and/or coating of the
additives, every effort should be made to ensure that
the powder density and the average grain size of the
particles do not deviate significantly from the
corresponding parameters of the spray-dried products
according to the invention and to ensure that the par-
ticles do not have too rough or too irregular a sur-
face. However, since the additional powder
-32-
. .
4 ~
constituents are generally not present in a proportion
of more than about 10 to 40% by weight, preferably up
to 30% by weight based upon the total weight of the
final mixture, the effect of the additives on the pro-
S perties of the powder is generally slight.
The following exemplary material is intended to
illustrate the invention and should not be construed as
limiting the invention thereto.
-33-
.
.,
~22~1L28~
_ X A M P L E S
EXAMPLE I
A spray-dried product having the following
composition:
Component % by Wei~t
Tallow alcohol + 14 EO ........................ 7.0
Tallow alcohol + 5 EO ......................... 6.0
Oleyl/cetyl alcohol (1:1 mixture)
+ 8 EO ...................................... 9.5
Sodium tripolyphosphate ...................... 38.0
Zeolite NaA .................................. 12.5
Sodium silicate tNa2O:SiO2 = 1:2) ............. 9.0
Na-carboxymethyl cellulose ...........,........ 0.5
Na-nitrilotriacetate ...................... .... 0.5
Optical bri~htener ........................ .... 0.2
Sodium hydroxide ..................... ~........ 0.5
Sodium sulfate ............................... 0. 5
Water (13.8% of which is volatile
at 130C) .................................. 15.8
Total : 100.0
was prepared as follows:
The sodium hydroxide in the form of a 50%
solution, the molten ethoxylates, and the sodium
silicate in the form of a 36% aqueous solution were
initially introduced, followed by the aluminosilicate
in the form of a filter-moist paste (54~ of water) and
the remaining constituents, predominantly in aqueous
solution, last of all the anhydrous phosphate.
-34-
.
~Z2~L2~39
After homogenization, the suspension, which had a total
water content of 48.~ and a temperature of 90C, was
sprayed into a spray-drying tower through spin nozzles
(orifice diameter of 4 mm) under a pressure measured at
the nozzle entrance of 20 bars.
The drying gas, introduced with spin and in coun-
tercurrent, had an entry temperature of 220C and an
exit temperature (measured at the filter entrance) of
90C. The dust explosion limit was not reached at a
powder concentration of from 30 to 200 gm/m3, i.e., the
product had a dust explosion rating of 0. The smoke
meter at the exit of the exhaust filter showed a
deflection of between 0.02 and 0.08 scale units
(permitted limit: 0.15 scale units), i.e., pluming did
not reach a critical level.
After leaving the spray-drying tower the spray-
dried product had a temperature of 70C, and it was
cooled in less than l minute to a temperature of 2~C
using a pneumatic conveyor.
More than 75~ by weight of the spray-dried product
consisted of elongate, i.e., rodlet-like to droplet-
like, particles having an average length of from about
0.8 to 3 mm and an average diameter of from about 0.1
to 0.6 mm, for an average ratio of diameter to length
of from about 1:1.5 to 1:6. I'he remainder of the pro-
duct consisted of irregularly agglomerated rodlet-like
particles and a small amount of dust. The content of
coarse particles (1.6-3 mm) amounted to less than 1% by
weight. The powder density of the powder measured 650
gm/l.
- :'
8~
To determine fluidity, 1 liter of the powder was
introduced into a funnel closed at its outlet end and
having the following dimensions:
(a) diameter of upper opening ............. 150 mm
(b~ diameter of lower opening ............. .lO mm
tc) height of the conical funnel section... 230 mm
(d) height of the lower cylindrical
section............................. 20 mm
(e) angle of inclination of the conical
section (to the horizontal)......... 70
For comparison, dry sea sand having the following grain
spectrum was used-
Particle Size (mm) % by Weight
< 0.1 3.1
> 0.1, < 0.2 30.1
> 0.2, < o.~ 54.7
> 0.4, < 0.8 11.9
~ 1.5 0.2
100.O
The flow-out time of the dry sand after release of
the outlet opening was put at 100%. The following com-
parison values were obtained (average values from 5
tests):
Test Material Flui~ity (%)
~a) Sand lO0
(b) Spray-dried product according
to invention 87
(c) Hollow-bead powder (commercial-
grade) 60-70
(d) Support grain produced by spray-
drying and aftertreated with
20% of nonionic surfactant 86
-36-
~;~2~,89
To make a final product, 87.0 parts by weight o~
the spray-dried product ~b) were mixed with
10 parts by weight of powder-form sodium per-
borate tetrahydrate, which had been sprayed
with 0.2 part by weight of perfume oil,
0.5 part by weight of an enzyme granulate
produced by prilling an enzyme melt, and
2.5 parts by weight of granulated tetraacetyl0
ethylene diamine,
the grain size of the added constituents being from
about 0.1 to 1 mm. The powder density was thus
increased to 700 gm/l. There was no change in
fluidity within the limits of error.
The mixture proved to be a high-quality detergent
usable at temperatures in the range from about 30 to
100C. With regard to flushability and residue for-
mation in the powder compartments of fully automatic
washing machines, there were no visible differences
between a loose spray-dried powder and the final pro-
duct according to the invention. By contrast, the
solubility properties of the comparison product (d)
were poorer, resulting in the formation of residues in
the powder compartments and on the textiles.
c
The spray-drying procedure of Example 1 was
repeated several times, with differing modifications.
The modifications were as follows:
Comparison
Example No. Modification
I The orifice diameter of the
spray nozzle was reduced to 2
mm for the same pressure (20
bars).
10 II The pressure was increased to
40 bars for a nozzle orifice
diameter of 3 mm.
III The pressure was increased to
40 bars for a nozzle orifice
diameter of 4 mm.
IV The pressure was reduced to 15
bars for a nozzle orifice
diameter of 5 mm.
V The temperature of the drying
gas was increased to 250C at
the entry end and to 94C at
the tower exit for a nozzle
orifice diameter of 4 mm and a
pressure of 20 bars.
As expanded, low specific gravity ( <500 gm/l)
spray-dried product of high dust content and poor
fluidity was obtained in Comparative Example I.
Expanded powders of low specific gravity were also
obtained in Comparative Examples II and III, the per-
centage coarse particle content showing a greater
increase with Comparative Example III. It was not
possible to obtain adequate drying in Comparative
Example IV; instead, a moist, lumpy, and unusable pro-
duct was formed.
-38-
~2~ 9
In Comparative Example V, the smoke meter showed a
reading of 2 scale units, which indicated that smoke
emission was over the permitted limit.
EXAMPLE 2
A spray-dried product having the following
composition:
Component ~ by Weight
Tallow alcohol + 14 EO ..................... 9.5
Tallow alcohol + 5 EO ...................... 5.0
Oleyl/cetyl alcohol tl:l mixture)
+ 8 E~ ................................... 7.5
Sodium tripolyphosphate t35% I-type) ...... 35.0
Zeolite NaA ............................... 14.5
Sodium silicate tNa2O:SiO2 = 1:2) .......... 8.8
Na-carboxymethyl cellulose ................. 0.5
Na-ethylenediaminotetramethylene
phosphate................................ 0.5
Optical brightener ......................... 0.2
Sodium hydroxide ........................... 0.5
Sodium sulfate ............................. 1.7
Water tof which 14.1~ is volatile
at 130C) ............................... 16.3
Total : 100.0
was prepared as follows:
The ingredients were mixed, as described in
Example 1, resulting in a slurry with a water content of
46.5% and a viscosity o 9,000 mPa.s. The slurry had
been heated to a temperature of 88.5DC by introducing
steam r before the addition of the :tripolyphosphate and
the zeolite took place. The suspension was sprayed
into a spray-drying tower through spin nozzles tori~ice
-39-
289
diameter 4.1 mm) under a pressure of 22 ~ars. The
drying gas introduced in counter-current had an entry
temperature (measured at the entry of the ring channel)
of 218C, and an exit temperature of 89.5C. The smoke
meter in the exhaust air showed a deflection of between
0.02 and 0.07 scale units, and with respect ~o the
powder concentration the same conditions existed as
given in Example 1. The powder leaving the spray-
drying tower was cooled in the conveyor shaft to 30C
with air of 24C.
The spray-dried product consisted of more than 60%
by weight of rodlet-like particles having an average
length of from 0.7 to 2.7 mm, and an average diameter
of from 0.1 to 0.7 mm for a ratio of diameter to length
of from 1~ to 1:5. The dust content was below 1% by
weight. The powder density was 6~5 g/l, and the
fluidity was 83%.
In a continuously used mixer the spray-dried pro-
duct was simultaneously mixed with 10% by weight of
sodium perborate and with 1.~% by weight of dry zeolite
NaA (particle size range 0.5 to 7 micron). After
admixing of 1% by weight of enzyme granulate and 3% by
weight of granulated bleach activator (tetraacetyl-
ethylenediamine), the powder density rose to 690 g/l
and the fluidity to 88~. The solubility in water was
good and not affected.
-40-
~z~
EX~MPLE 3
Example 1 was repeated but using a sodium tripoly-
phosphate having 40% of the I-type. Before the addi-
tion of the phosphate the slurry was heated to 90C and
subsequently pumped in closed circuit through a homoge-
nization device. The viscosity was 11,000 mPa.s, and
the water content was 43% by weight. The spraying was
done at a pressure of 22 bars and through a spin
nozzle orifice of 4.0 mm. The temperature of the
drying air applied in counter-current was 215C at the
tower entrance, and 89C at the tower exit. The other
process parameters were the same as used in Example 1.
With respect to grain particle size the powder
density the powder corresponded to that of Example 1.
The fluidity was 86~ of that of dry sand. An ater
treatment with 0.06% by weight of silicic acid aerogel
~Aerosil~) improved the fluidity to 89% and resulted in
an increase in powder density from 640 g/l to 660 g/1.
EXAMPLE 4
Example 2 was repeated, however, with using a
cooling air of 37C. Because oE the delayed cooling of
the warm spray-dried powder, a slight sweating out of
the nonionic surfactants at the surface of t~e grains
was observed. Therefore, the fluidity of the powder
decreased to 81% and the powder density to 620 g/l. ~y
after-treatment with 1% by weight of zeolite NaA in a
continuously working mixer the fluidity was improved to
86%, and the powder density was raised to 640 g/l.
-41-
~2;~12~B~
In the foregoing examples the viscosity was deter-
mined by a rotation viscosimeter of Messrs. Brabender,
Duisburg, Federal Republic of Germany.
EX~MPLE 5
In a continuously working mixer 89 parts by weight
of the spray-dried product of Example 1 were mi~ed
with 1 part by weight of an enzyme granulate and 10
parts by weight of a surfactant compound. The surfac-
tant compound was produced by spray mixing thefollowing composition:
Component ~ bY Weight
Na-dodecylbenzolsufonate...................... 24.0
Na-cocofattyalcoholsulfate.................... 24.0
Zeolite NaA .................................. 15.0
Sodium tripolyphosphate ...................... 15.0
Water glass................................... 10.0
Sodium sulfate ............................... 2.0
Water............... ~.............................. 10.0
Total : 100.0
The powder density measured 350 g/l, the grain size
distribution was in the range of from 0.1 to 1.6 mm.
Thus a strongly foaming detergent composition was
obtained with a powder density of 620 g/l.
The preceding specific embodiments are illustra-
tive 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.
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