Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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PROCESS FOR THE PRODUCTION OF PREPARATIONS CONTAINING
CO-BUILDERS
Field of the Invention
This invention relates to a process for the production of powder-
form, pourable and free-flowing preparations containing certain co-builders
and organic and/or inorganic carrier material and to their use as premixes
(compounds) for the production of particulate detergents.
Background of the Invention
Besides the surfactants essential for cleaning performance,
detergents normally also contain so-called builders of which the function is
to support the performance of the surfactants by eliminating hardness salts,
i.e. essentially calcium and magnesium ions, from the wash liquor so that
they are unable to interact negatively with the surfactants. A well-known
example of such builders, which improve single wash cycle performance, is
zeolite NaA which is known to be capable of forming such stable
complexes, particularly with calcium ions, that their reaction with anions
responsible for water hardness, particularly carbonate, to form insoluble
compounds is suppressed. In addition, builders are intended, particularly in
laundry detergents, to prevent redeposition of the soil detached from the
fibers or generally from the surface to be cleaned and also insoluble
compounds formed by the reaction of cations forming water hardness with
anions forming water hardness onto the cleaned laundry or rather the
surface. So-called co-builders are normally used for this purpose. Co-
builders are generally polymeric polycarboxylates which advantageously
have a complexing effect on the cations forming water hardness in addition
to the contribution the make towards multiple wash cycle performance.
Particulate detergents generally consist of several separately
produced solid components which necessitate different production
processes according to their nature of their ingredients. A preferred
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production process for the builder- and surfactant-containing component of
such detergents is the relatively uncomplicated spray drying of a an
aqueous solution or slurry of the ingredients. However, this particular
process does presuppose heat resistance on the part of the constituents
which is guaranteed where hitherto standard builder systems, particularly
based on inorganic materials, such as phosphates, zeolites or layer
silicates, are used. Even polymeric polycarboxylates, such as the usual
polymers synthesized from acrylic acid and malefic acid, and monomeric
co-builders, such as alkali metal citrates, can normally be spray-dried
without difficulty as a constituent of aqueous slurries in the production of
detergents.
If it is intended to use organic co-builders, which may assumed from
their molecular composition to be more readily biodegradable than the
polymeric polycarboxylates mentioned, the problem arises that these
substances in particular lack heat resistance and, when used in
conventional spray drying processes, lead to more or less strongly colored
powders which cannot be incorporated in particulate detergents. This
problem is very pronounced with co-builders based on oligomeric or
polymeric saccharides, among which the oxidized dextrin derivatives are
particularly mentioned here.
The oxidized derivatives of dextrins are their reaction products with
oxidizing agents which are capable of oxidizing at least one alcohol
function of the saccharide ring to the carboxylic acid function, dextrins
being understood to be oligomers or polymers of carbohydrates obtainable,
for example, by partial hydrolysis of starch. The hydrolysis may be carried
out by standard methods, for example acid- or enzyme-catalyzed methods.
The end products are preferably oligomers or polymers with average
molecular weights of 440 to 500,000 or with dextrose equivalents (DE) of
0.5 to 40 and, more particularly, 2 to 30, the DE being an accepted
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measure of the reducing effect of a polysaccharide by comparison with
dextrose which has a DE of 100. Both maltodextrins (DE 3 to 20) and dry
glucose sirups (DE 20 to 37) and also so-called yellow dextrins and white
dextrins with relatively high molecular weights of ca. 2,000 to 30,000 may
be used. A preferred dextrin is described in European patent application
EP 0 703 292. Oxidized dextrins obtainable from these dextrins and
processes for their production are known, for example, from European
patent applications EP 0 427 349, EP 0 472 042 and EP 0 542 496 and
from International patent applications WO 93108251, WO 93116110, WO
95107303 and WO 95/12619. A product oxidized at C6 of the saccharide
ring obtainable by the process according to any of International patent
applications WO 93116110, WO 94/28030, WO 95/20608 and WO
96103429 is preferably used. In addition, however, preference is also
attributed above all to the use of dextrins which have been oxidatively
modified at their originally reducing end with the loss of 1 carbon atom. If
the originally reducing end of the oligosaccharide was an anhydroglucose
unit, an arabinonic acid unit is present after the modification:
(glucose)+~ ~ (glucose)n arabinonic acid.
In these dextrins, the average degree of oligomerization n, which as an
analytically determined quantity may also be a broken number, is
preferably in the range from 2 to 20 and more preferably in the range from
2 to 10. This oxidative modification may be carried out, for example, using
Fe, Cu, Ag, Co or Ni catalysts as described in International patent
application WO 92118542, using Pd, Pt, Rh or Os catalysts as described in
European patent EP 0 232 202 or using a quinone/hydroquinone system in
the alkaline range in conjunction with oxygen, optionally followed by
aftertreatment with hydrogen peroxide.
Summary of the Invention
The present invention relates to a process for the production of
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powder-form, pourable and free-flowing preparations which contain co-
builders and organic and/or inorganic carrier material and are suitable for
the production of particulate detergents by drying flowable, aqueous,
surfactant-containing mixtures of their constituents, characterized in that an
oxidized dextrin derivative is mixed with inorganic builder, surfactant and
water in such a quantity that a mixture flowable and pumpable at
temperatures below 80°C is formed and the water is removed from the
mixture thus formed by spray drying using drying gases with temperatures
in the range from 160°C to 260°C to such an extent that a powder-
form
free-flowing product is formed. This is normally the case at water contents
of the powder product of about 2% by weight to 15% by weight, water
contents being understood here to be contents of water which can be
removed by heating to temperatures of up to 200°C.
The expression "carrier material" used here is intended to designate
the other ingredients besides the co-builder essential to the invention which
are present in the powder-form preparation. These other ingredients may
be selected from all the usual ingredients of detergents which do not
interact unreasonably with the co-builder essential to the invention during
production or subsequent storage and which withstand the spray drying
process without an unreasonable loss of activity. The quantities in which
the other ingredients are present will largely be determined by the fact that
the preparation obtained by the process according to the invention must be
a powder-form preparation. Accordingly, the ingredients solid at room
temperature will generally represent by far the greatest part of the carrier
material.
Detailed Description of the Invention
Of these ingredients, inorganic builders are mentioned first and
foremost, i.e. in particular zeolites, silicates, carbonates and - providing
there are no ecological objections to their use - the phosphates. Inorganic
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builders such as these are present in the compounds produced by the
process according to the invention in quantities of preferably 25% by
weight to 75% by weight and more preferably 30% by weight to 65% by
weight.
5 The finely crystalline, synthetic detergent-range zeolite containing
bound water used in accordance with the invention is preferably zeolite A
and/or zeolite P. Zeolite MAP~ (Crosfield) is a particularly preferred P-type
zeolite. However, zeolite X and mixtures of A, X and/or P are also suitable.
According to the invention, it is preferred to use, for example, a
commercially obtainable co-crystallizate of zeolite X and zeolite A (ca. 80%
by weight zeolite X) which is marketed by CONDEA Augusta S.p.A. under
the name of VEGOBOND AX~ and which may be described by the
following formula:
nNa20 ~ (1-n)K20 ~ AI203 ~ (2 - 2.5)Si02 ~ (3.5 - 5.5) H20.
Suitable zeolites preferably have a mean particle size of less than 10 ~,m
and contain preferably 18 to 22% by weight and more preferably 20 to 22%
by weight of bound water.
Suitable crystalline layer-form sodium silicates correspond to the
general formula Na2MSiX02x+~~yH20, where M is sodium or hydrogen, x is a
number of 1.9 to 4 and y is a number of 0 to 20, preferred values for x
being 2, 3 or 4. Crystalline layer silicates such as these are described, for
example, in European patent application EP-A-0 164 514. Preferred
crystalline layer silicates corresponding to the above formula are those in
which M is sodium and x assumes the value 2 or 3. Both ~- and ~-sodium
disilicates Na2Si205~yH20 are particularly preferred, ~3-sodium disilicate
being obtainable, for example, by the process described in International
patent application WO 91/08171.
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Amorphous sodium silicates with a modulus (Na20:Si02 ratio) of 1:2
to 1:3.3, preferably 1:2 to 1:2.8 and more preferably 1:2 to 1:2.6 which
dissolve with delay and exhibit multiple wash cycle properties may also be
used. The delay in dissolution in relation to conventional amorphous
sodium silicates can have been obtained in various ways, for example by
surface treatment, compounding, compacting or by overdrying. In the
context of the invention, the term "amorphous" is also understood to
encompass "X-ray amorphous". In other words, the silicates do not
produce any of the sharp X-ray reflexes typical of crystalline substances in
X-ray diffraction experiments, but at best one or more maxima of the
scattered X-radiation which have a width of several degrees of the
diffraction angle. Particularly good builder properties may even be
achieved where the silicate particles produce crooked or even sharp
diffraction maxima in electron diffraction experiments. This may be
interpreted to mean that the products have microcrystalline regions
between 10 and a few hundred nm in size, values of up to at most 50 nm
and, more particularly, up to at most 20 nm being preferred. So-called X-
ray amorphous silicates such as these, which dissolve with delay compared
with the conventional waterglasses, are described, for example, in German
patent application DE 44 00 024. Compacted amorphous silicates,
compounded amorphous silicates and overdried X-ray-amorphous silicates
are particularly preferred.
The generally known phosphates may of course also be used as
builders providing their use should not be avoided on ecological grounds.
Among the large number of commercially available phosphates, alkali
metal phosphates have the greatest importance in the detergent industry,
pentasodium triphosphate and pentapotassium triphosphate (sodium and
potassium tripolyphosphate) being particularly preferred.
"Alkali metal phosphates" is the collective term for the alkali metal
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(more particularly sodium and potassium) salts of the various phosphoric
acids, including metaphosphoric acids (HP03)" and orthophosphoric acid
(H3P04) and representatives of higher molecular weight. The phosphates
combine several advantages: they act as alkalinity sources, prevent lime
deposits on machine parts and lime incrustations in fabrics and, in addition,
contribute towards the cleaning effect.
If desired, other organic co-builders, more particularly
polycarboxylates/polycarboxylic acids, polymeric polycarboxylates,
polymeric aspartic acid, polyacetals and phosphonates, may be used in
addition to the oxidized dextrin. Co-builders belonging to these classes are
described in the following although their use in the process according to the
invention is not preferred. In a preferred embodiment of the invention,
other organic co-builders are only used in small quantities by comparison
with the oxidized dextrin derivative. Another preferred embodiment of the
invention is characterized by the complete absence of, in particular, the
polycarboxylates/polycarboxylic acids mentioned below .
Suitable organic builders are, for example, polycarboxylic acids
usable in the form of their sodium salts, polycarboxylic acids being
understood to be carboxylic acids which bear more than one acid function.
Examples of such polycarboxylic acids include citric acid, adipic acid,
succinic acid, glutaric acid, malic acid, tartaric acid, malefic acid, fumaric
acid, sugar acids, aminocarboxylic acids, nitrilotriacetic acid (NTA),
providing their use is not ecologically unsafe, and mixtures thereof. The
acids per se may also be used. Besides their builder effect, the acids also
typically have the property of an acidifying component and, hence, also
serve to establish a relatively low and mild pH value in detergents. Citric
acid, succinic acid, glutaric acid, adipic acid, gluconic acid and mixtures
thereof are particularly mentioned in this regard.
Other suitable co-builders are polymeric polycarboxylates such as,
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for example, the alkali metal salts of polyacrylic or polymethacrylic acid,
for
example those with a relative molecular weight of 500 to 70,000 g/mole.
The molecular weights mentioned in this specification for polymeric
polycarboxylates are weight-average molecular weights MW of the particular
acid form which, basically, were determined by gel permeation
chromatography (GPC) using a UV detector. The measurement was
carried out against an external polyacrylic acid standard which provides
realistic molecular weight values by virtue of its structural similarity to
the
polymers investigated. These values differ distinctly from the molecular
weights measured against polystyrene sulfonic acids as standard. The
molecular weights measured against polystyrene sulfonic acids are
generally higher than the molecular weights mentioned in this specification.
Particularly suitable polymers are polyacrylates which preferably
have a molecular weight of 2,000 to 20,000 g/mole. By virtue of their
superior solubility, preferred representatives of this group are the short-
chain polyacrylates which have molecular weights of 2,000 to 10,000
g/mole and, more particularly, 3,000 to 5,000 g/mole.
Also suitable are copolymeric polycarboxylates, particularly those of
acrylic acid with methacrylic acid and those of acrylic acid or methacrylic
acid with malefic acid. Acrylic acid/maleic acid copolymers containing 50 to
90% by weight of acrylic acid and 50 to 10% by weight of malefic acid have
proved to be particularly suitable. Their relative molecular weights, based
on the free acids, are generally in the range from 2,000 to 70,000 g/mole,
preferably in the range from 20,000 to 50,000 g/mole and more preferably
in the range from 30,000 to 40,000 g/mole.
The (co)polymeric polycarboxylates may be used either in powder
form or in the form of an aqueous solution. The content of (co)polymeric
polycarboxylates in the detergent, if desired, is from 0.5 to 20% by weight
and more preferably from 3 to 10% by weight.
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In order to improve solubility in water, the polymers may also contain
allyl sulfonic acids, such as allyloxybenzene sulfonic acid and methallyl
sulfonic acid, as monomer.
Other particularly preferred polymers are biodegradable polymers of
more than two different monomer units, for example those which contain
salts of acrylic acid and malefic acid and vinyl alcohol or vinyl alcohol
derivatives as monomers or those which contain salts of acrylic acid and 2-
alkylallyl sulfonic acid and sugar derivatives as monomers.
Other preferred copolymers are those which are described in
German patent applications DE-A-43 03 320 and DE-A-44 17 734 and
which preferably contain acrolein and acrylic acid/acrylic acid salts or
acrolein and vinyl acetate as monomers.
Other preferred builders are polymeric aminodicarboxylic acids, salts
or precursors thereof. Particular preference is attributed to polyaspartic
acids or salts and derivatives thereof which, according to German patent
application DE-A-195 40 086, are also said to have a bleach-stabilizing
effect in addition to their co-builder properties.
Other suitable builders are polyacetals which may be obtained by
reaction of dialdehydes with polyol carboxylic acids containing 5 to 7
carbon atoms and at least three hydroxyl groups. Preferred polyacetals
are obtained from dialdehydes, such as glyoxal, glutaraldehyde, terephthal-
aldehyde and mixtures thereof and from polyol carboxylic acids, such as
gluconic acid and/or glucoheptonic acid.
Other suitable co-builders are oxydisuccinates and other derivatives
of disuccinates, preferably ethylenediamine disuccinate. Ethylenediamine-
N,N'-disuccinate (EDDS) is preferably used in the form of its sodium or
magnesium salts. Glycerol disuccinates and glycerol trisuccinates are also
preferred in this connection. The quantities used in zeolite-containing
and/or silicate-containing formulations, if desired, are from 3 to 15% by
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weight.
Other useful organic co-builders are, for example, acetylated
hydroxycarboxylic acids and salts thereof which may optionally be present
in lactone form and which contain at least 4 carbon atoms, at least one
5 hydroxy group and at most two acid groups. Co-builders such as these are
described, for example, in International patent application WO-A-95/20029.
Another class of substances with co-builder properties are the
phosphonates, more particularly hydroxyalkane and aminoalkane phos-
phonates. Among the hydroxyalkane phosphonates, 1-hydroxyethane-1,1-
10 diphosphonate (HEDP) is particularly important as a co-builder. It is
preferably used in the form of the sodium salt, the disodium salt showing a
neutral reaction and the tetrasodium salt an alkaline reaction (pH 9).
Preferred aminoalkane phosphonates are ethylenediamine tetramethylene
phosphonate (EDTMP), diethylenetriamine pentamethylenephosphonate
(DTPMP) and higher homologs thereof. They are preferably used in the
form of the neutrally reacting sodium salts, for example as the hexasodium
salt of EDTMP or as the hepta- and octasodium salts of DTPMP. Of the
phosphonates, HEDP is preferably used as a builder. In addition, the
aminoalkane phosphonates have a pronounced heavy metal binding
capacity. Accordingly, it can be of advantage, particularly where the
detergents also contain bleach, to use aminoalkane phosphonates, more
particularly DTPMP, or mixtures of the phosphonates mentioned.
In addition, any compounds capable of forming complexes with
alkaline earth metal ions may be used as co-builders.
The quantity of builder component, i.e. the sum of builder and co-
builder, including the oxidized dextrin derivative essential to the invention,
in the compound produced in accordance with the invention is normally
between 40 and 80% by weight, preferably between 45 and 70% by weight
and more preferably between 50 and 65% by weight. The oxidized dextrin
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preferably makes up 5% by weight to 50% by weight and more preferably
10% by weight to 25% by weight of the builder component as a whole.
In addition, the aqueous slurries to be spray dried in acordance with
the invention contain a surfactant which may be selected from anionic,
nonionic, cationic and/or amphoteric surfactants or mixtures thereof.
Mixtures of anionic and nonionic surfactants are preferred from the
performance perspective. The total surfactant content of the compounds
produced by the process according to the invention is preferably in the
range from 5% by weight to 30% by weight and more preferably in the
range from 7% by weight to 25% by weight.
The anionic surfactants used are, for example, those of the sulfonate
and sulfate type. Suitable surfactants of the sulfonate type are preferably
C9_~3 alkyl benzenesulfonates, olefin sulfonates, i.e. mixtures of alkene and
hydroxyalkane sulfonates, and the disulfonates obtained, for example, from
C~2_~a monoolefins with an internal or terminal double bond by sulfonation
with gaseous sulfur trioxide and subsequent alkaline or acidic hydrolysis of
the sulfonation products. Other suitable surfactants of the sulfonate type
are the alkane sulfonates obtained from C~2_~8 alkanes, for example by
sulfochlorination or sulfoxidation and subsequent hydrolysis or
neutralization. The esters of a-sulfofatty acids (ester sulfonates), for
example the a-sulfonated methyl esters of hydrogenated coconut oil, palm
kernel oil or tallow fatty acids, are also suitable.
Other suitable anionic surfactants are sulfonated fatty acid glycerol
esters, i.e. the monoesters, diesters and triesters and mixtures thereof
which are obtained where production is carried out by esterification of a
monoglycerol with 1 to 3 moles of fatty acid or in the transesterification of
triglycerides with 0.3 to 2 moles of glycerol. Preferred sulfonated fatty acid
glycerol esters are the sulfonation products of saturated fatty acids
containing 6 to 22 carbon atoms, for example caproic acid, caprylic acid,
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capric acid, myristic acid, lauric acid, palmitic acid, stearic acid or
behenic
acid.
Preferred alk(en)yl sulfates are the alkali metal salts and, in
particular, the sodium salts of the sulfuric acid semiesters of C~2_~$ fatty
alcohols, for example coconut alcohol, tallow alcohol, lauryl, myristyl, cetyl
or stearyl alcohol, or Coo-2o oxoalcohols and the corresponding semiesters
of secondary alcohols with the same chain length. Other preferred
alk(en)yl sulfates are those with the chain length mentioned which contain
a synthetic, linear alkyl chain based on a petrochemical and which are
similar in their degradation behavior to the corresponding compounds
based on oleochemical raw materials. C~2_~s alkyl sulfates and C~2_~5 alkyl
sulfates and also C~4-15 alkyl sulfates alkyl sulfates are particularly
preferred
from the washing performance point of view. Other suitable anionic
surfactants are 2,3-alkyl sulfates which may be produced, for example, in
accordance with US 3,234,258 or US 5,075,041 and which are
commercially obtainable as products of the Shell Oil Company under the
name of DAN~.
The sulfuric acid monoesters of linear or branched C~_2~ alcohols
ethoxylated with 1 to 6 moles of ethylene oxide, such as 2-methyl-branched
C9_~~ alcohols containing on average 3.5 moles of ethylene oxide (EO) or
C~2_1g fatty alcohols containing 1 to 4 EO, are also suitable. In view of
their
high foaming capacity, they are normally used in only relatively small
quantities, for example in quantities of 1 to 5% by weight, in detergents.
Other suitable anionic surfactants are the salts of alkyl sulfosuccinic
acid which are also known as sulfosuccinates or as sulfosuccinic acid
esters and which represent monoesters and/or diesters of sulfosuccinic
acid with alcohols, preferably fatty alcohols and, more particularly,
ethoxylated fatty alcohols. Preferred sulfosuccinates contain C8_~$ fatty
alcohol molecules or mixtures thereof. Particularly preferred
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sulfosuccinates contain a fatty alcohol molecule derived from ethoxylated
fatty alcohols which, considered in isolation, represent nonionic surfactants
(for a description, see below). Of these sulfosuccinates, those of which the
fatty alcohol molecules are derived from narrow-range ethoxylated fatty
alcohols are particularly preferred. Alk(en)yl succinic acid preferably
containing 8 to 18 carbon atoms in the alk(en)yl chain or salts thereof may
also be used.
Other suitable anionic surfactants are, in particular, soaps. Suitable
soaps are, in particular, saturated fatty acid soaps, such as the salts of
lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated erucic
acid and behenic acid, and soap mixtures derived in particular from natural
fatty acids, for example coconut, palm kernel or tallow acids.
The anionic surfactants, including the soaps, may be present in the
form of their sodium, potassium or ammonium salts and as soluble salts of
organic bases, such as mono-, di- or triethanolamine. The anionic
surfactants are preferably present in the form of their sodium or potassium
salts and, more preferably, in the form of their sodium salts.
Preferred nonionic surfactants are alkoxylated, advantageously
ethoxylated, more particularly primary alcohols preferably containing 8 to
18 carbon atoms and an average of 1 to 12 moles of ethylene oxide (EO)
per mole of alcohol, in which the alcohol radical may be linear or,
preferably, 2-methyl-branched or may contain linear and methyl-branched
radicals in the form of the mixtures typically present in oxoalcohol radicals.
However, alcohol ethoxylates containing linear radicals of alcohols of native
origin with 12 to 18 carbon atoms, for example coconut alcohol, palm oil
alcohol, tallow alcohol or oleyl alcohol, and an average of 2 to 8 EO per
mole of alcohol are particularly preferred. Preferred ethoxylated alcohols
include, for example, C~2_~4 alcohols containing 3 EO or 4 EO, C9_~~ alcohol
containing 7 EO, C~3_~5 alcohols containing 3 EO, 5 EO, 7 EO or 8 EO,
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C~2_~8 alcohols containing 3 EO, 5 EO or 7 EO and mixtures thereof, such
as mixtures of C~2_~a alcohol containing 3 EO and C~2_~$ alcohol containing
EO. The degrees of ethoxylation mentioned are statistical mean values
which, for a special product, may be either a whole number or a broken
5 number. Preferred alcohol ethoxylates have a narrow homolog distribution
(narrow range ethoxylates, NRE). In addition to these nonionic surfactants,
fatty alcohols containing more than 12 EO may also be used, as described
above. Examples of such fatty alcohols are (tallow) fatty alcohols
containing 14 EO, 25 EO, 30 EO or 40 EO.
In addition, other nonionic surfactants which may be used are alkyl
glycosides with the general formula RO(G)X where R is a primary, linear or
methyl-branched, more particularly 2-methyl-branched, aliphatic radical
containing 8 to 22 and preferably 12 to 18 carbon atoms and G is a glycose
unit containing 5 or 6 carbon atoms, preferably glucose. The degree of
oligomerization x, which indicates the distribution of monoglycosides and
oligoglycosides, is a number of 1 to 10 and preferably a number of 1.2 to
1.4.
Nonionic surfactants of the amine oxide type, for example N-
cocoalkyl-N,N-dimethylamine oxide and N-tallowalkyl-N,N-dihydroxyethyl
amine oxide, and the fatty acid alkanolamide type are also suitable. The
quantity in which these nonionic surfactants are used is preferably no more,
in particular no more than half, the quantity of ethoxylated fatty alcohols
used.
Other suitable surfactants are polyhydroxyfatty acid amides cor-
responding to formula (II):
R'
R-CO-N-[Z] (I I)
in which RCO is an aliphatic acyl group containing 6 to 22 carbon atoms,
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R' is hydrogen, an alkyl or hydroxyalkyl group containing 1 to 4 carbon
atoms and [Z] is a linear or branched polyhydroxyalkyl group containing 3
to 10 carbon atoms and 3 to 10 hydroxyl groups. The polyhydroxyfatty acid
amides are known substances which are normally obtained by reductive
5 amination of a reducing sugar with ammonia, an alkylamine or an
alkanolamine and subsequent acylation with a fatty acid, a fatty acid alkyl
ester or a fatty acid chloride.
The group of polyhydroxyfatty acid amides also includes compounds
corresponding to formula (III):
R~-O-R2
(III)
R-CO-N-[Z]
in which R is a linear or branched alkyl or alkenyl group containing 7 to 12
carbon atoms, R' is a linear, branched or cyclic alkyl group or an aryl group
containing 2 to 8 carbon atoms and R2 is a linear, branched or cyclic alkyl
group or an aryl group or a hydroxyalkyl group containing 1 to 8 carbon
atoms, C~_4 alkyl or phenyl groups being preferred, and [Z] is a linear
polyhydroxyalkyl group, of which the alkyl chain is substituted by at least
two hydroxyl groups, or alkoxylated, preferably ethoxylated or
propoxylated, derivatives of such a group. [Z] is preferably obtained by
reductive amination of a reduced sugar, for example glucose, fructose,
maltose, lactose, galactose, mannose or xylose. The N-alkoxy or N-
aryloxy-substituted compounds may then be converted into the required
polyhydroxyfatty acid amides by reaction with fatty acid methyl esters in the
presence of an alkoxide as catalyst, for example in accordance with the
teaching of International patent application WO-A-95107331.
According to the invention, the procedure preferably adopted is
characterized in that 1 part by weight to 5 parts by weight, more particularly
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2 parts by weight to 4 parts by weight, of surfactant, more particularly
anionic surfactant, 2 parts by weight to 15 parts by weight, more particularly
parts by weight to 10 parts by weight, of inorganic builder, 1 part by
weight of oxidized dextrin derivative and optionally other sprayable
5 detergent ingredients are mixed with water in such a quantity that a
pumpable and transportable slurry is obtained and is then spray dried, i.e.
after the aqueous slurry has been atomized into small droplets, it is
contacted with hot drying gas. The powder products formed from the
sprayed droplets preferably never reach temperatures higher than 120°C.
The aqueous slurries to be spray dried preferably contain no optical
brightener, above all no diaminostilbene disulfonic acids or Biphenyl styryls,
because in their presence the color impression of the powders formed is
not optimal.
The aqueous slurries are spray dried in so-called spray towers in the
upper part of which the slurry is sprayed through pressure nozzles to form
fine droplets which move under the effect of gravity into the lower part of
the spray tower, coming into contact with hot drying gases flowing in co-
current with or preferably in countercurrent to the particles to be dried. It
is
important to ensure that the temperature of the drying gases is not too
high. In the context of the invention, this means that the temperature of the
drying gases does not exceed 260°C and is preferably in the range from
160°C to 240°C and more preferably in the range from
180°C to 220°C, the
temperature of the drying gas being measured at the hottest point of the
spray tower, the so-called ring channel.
The compounds produced in accordance with the invention may be
converted into the corresponding end products by mixing with other
particulate constituents of detergents, more particularly bleaching agents,
bleach activators, particulate enzymes, such as proteases, amylases,
lipases, cellulases and mixtures thereof, particulate foam regulators or
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perfumes (so-called perfume beads). Liquid ingredients, including in
particular nonionic surfactants and perfumes and optical brighteners
optionally mixed with water and/or nonionic surfactant, may be sprayed
onto the compounds produced in accordance with the invention beforehand
or during the mixing process. The compounds produced in accordance
with the invention may also be subjected to a compacting aftertreatment,
optionally in admixture with other ingredients. Detergents of high bulk
density, more particularly in the range from 650 to 950 g/I, are preferably
produced by the process comprising an extrusion step which is known from
European patent EP 0 486 592. Another preferred production process is
the granulation process according to European patent EP 0 642 576. To
produce detergents in the form of tablets which comprise one or more
phases and are colored in one or more colors and, in particular, may
consist of one layer or several layers, more particularly two layers, all the
ingredients - optionally for each layer - may be mixed together in a mixer
and the resulting mixture tabletted in conventional tablet presses, for
example eccentric presses or rotary presses. In the case of multilayer
tablets in particular, it can be of advantage if at least one layer is
compressed in advance. A tablet produced in this way preferably has a
weight of 10 g to 50 g and, more particularly, 15 g to 40 g. The tablets may
be of any shape, including round, oval or angular and variations thereof.
Corners and edges are advantageously rounded off. Round tablets
preferably have a diameter of 30 mm to 40 mm.
ExamQles
Aqueous slurries S1, S2 and S3 were produced from the raw
materials listed in Table 1. These slurries were heated to temperatures of
about 60°C to 80°C and sprayed under pressure into a drying
tower
through which hot air (temperature ca. 200°C in the ring channel)
flowed in
CA 02315136 2000-08-04
18
countercurrent to the slurries. Free-flowing powders M1, M2 and M3 with
mean particle sizes of around 300 pm were obtained. The powders were
free from particles above 1.6 mm in diameter, contained at most 1 % by
weight of dust (diameter < 0.1 mm) and had the water contents (H20; % by
weight), bulk densities (BD; g/I) and standard color values (Y) shown in
Table 2.
Table 1:1:
Composition [kq] of the aaueous slurries
S1 S2 S3
Na alkyl benzenesulfonate 326 252 273
7x-Ethoxylated fatty alcohol- 16 58
Caustic soda 116 91 87
Fatty acid 28 22.5 20
Zeolite NaA 1833 1411 801
Sodium silicate 1 83.5 126
Oxidized dextrin 280 224 170
Sodium carbonate 160 108 74
Sod iu m su Ifate 162 544 352
Phosphonate 17 14 -
Polyvinyl pyrrolidone - - 25
Water to 2000to 2000 to 2000
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Table 2
H20 BD Y
M 13.7 390 72.42
1
M2 7.5 480 76.16
M3 7 424 72.08
The invention may be varied in any number of ways as would be
apparent to a person skilled in the art and all obvious equivalents and the
like are meant to fall within the scope of this description and claims. The
description is meant to serve as a guide to interpret the claims and not to
limit them unnecessarily.
