Note: Descriptions are shown in the official language in which they were submitted.
21~0~8~
94/02574 PC~r/US93/05888
DETERGENT COMPOSITIONS
FIELD OF THE Ihv~NllON
Currently there is a trend towards compact detergents
which offer the consumer a product which is more convenient
to carry and store, as well as reducing the weight of
packaging material~ used. In order to manufacture these
compact detergents, there is a need to use high density,
high activity granules/agglomerates
One problem which is associated with such high
activity particles is the discoloration of the organic
surfactant material.
Such discoloration is highly undesirable in a finished
detergent product and can cause detergent granules made
from a paste of anionic detergent salts to be yellow in
colour which is unacceptable to the consumer and therefore
SUBSTITUTE SHEET
W O 94/02574 ~ 5 PC~r/US93/05888
not commercially viable.This problem is particularly acute
in granules which have a high activity of organic
surfactant.
one way of making high active detergent granules is by
agglomeration of high active pastes consisting of the salts
of anionic surfactants with detergent powders. Such pastes
have rarely been handled before in the detergent industry
for various reasons, including the practical difficulties
in handling high viscosity pastes and the need to maintain
high temperatures in order to prevent solidification of the
material, and the problems associated with discoloration.
There is a need, for a consumer acceptance point-of-
view, to make high active detergent granules which have a
white, or near-white appearance. According to Herman de
Groot, W. "Sulphonation Technology in the Detergent
Industry", Kluwer Academic Publishers, 1991, a common
approach to improving colour is by bleaching of dark,
organic compounds, especially anionic surfactants like
linear alkyl benzene sulphonate (LAS) or methyl ester
sulphonate (MES). Bleaching is achieved by an agent which
disrupts the conjugated carbon double bonds, either by
reaction with one of the conjugated double bonds or by
oxidation and/or reduction of the chromophore. There is a
variety of bleaching agents potentially available for this
purpose but only sodium hypochlorite and hydrogen peroxide
have commercial importance. Sodium hypochlorite is a more
convenient and efficient bleach than hydrogen peroxide.
However, chlorine-based bleach may be undesirable due to
the potential to generate sensitisers during the process of
some feedstocks. As an alternative, hydrogen peroxide may
be used, but is less cost-efficient and can cause process
control difficulties due to excessive foaming caused by the
liberation of oxygen during bleaching.
SUBSTITUTE SHEET
3 ~ 5
GB 1 369 269, published on October 2nd, 1974, describes
a process of dry neutralisation for making detergent
granules. It says that various difficulties are encountered
including local discoloration of the organic detergent.
However no solutions are specifically given to this problem.
GB 2 221 695, published on February 14th, 1990, also
describes a dry neutralisation process. It says that
various adjuvants may be added with the neutralising agent,
but there are no benefits suggested from adding brighteners
or dyes, apart from it being a convenient process route for
many adjuvants.
GB 2 166 452, published on May 8th, 1986, describes a
processing route which involves dispersing organic materials
with particles of an inorganic component to form solid
pellets which may then be granulated. A wide choice of
detergent ingredients which may be added upon neutralisation
is suggested, including, blueing agents, fluorescent dyes
and pigments. However, once again, there is no suggestion
of any particular benefit to be gained from choosing these
ingredients.
EPA 327 963, published on August 16th, 1989, discloses
a method of pre-neutralising the surfactant acids in a
slurry, spray-drying the slurry to form a powder and
densifying said powder. Brighteners may be incorporated
into the slurry as a convenient way of bringing them into
the finished composition, but there is no suggestion that
this is of benefit to the colour of the densified granules.
U.S. Patents 5,486,317, 5,451,354 and CA 2,108,167,
form part of the prior art under Art 54(3) EPC. These
applications disclose detergent compositions, and processes
for making such compositions from high active detergent
pastes. The addition of an optical brightener in the
finished detergent composition is disclosed but there is no
sBl
4 7 ~ k ~ ~ ~ 5
mention of using dyes or optical brightener in the high
active detergent pastes to avoid the discolouration problem,
nor is the addition of dyes or brighteners into the high
shear mixer disclosed.
These new processes, based on high active detergent
pastes, enable manufacture of granules having a higher
surfactant activity than before, which may lead to the
discoloration problems caused by feedstocks in the form of
hot surfactant pastes.
It is an aim of the present invention to provide a
composition of a high active paste of detergent salts which
comprises specific ingredients which give a very acceptable
white appearance to the finished detergent granules.
It is a further aim of the present invention to provide
a process for making a concentrated detergent powder which
combines high activity, high bulk density and consumer
acceptable colour.
SUMMARY OF THE INVENTION
One embodiment of the invention is a process for making
a high active detergent granule comprising the steps of
dispersing organic detergent component, with particles of an
inorganic component in the presence of a dye, characterized
by the steps of: (i) making a high active detergent paste
comprising at least 40~ by weight anionic surfactant salts,
by neutralization of the corresponding acids, said paste
having a viscosity of at least 10 Pa.s when measured at a
temperature of 70~C and a shear rate of 25 s-1, said paste
composition comprising at least 5~ by weight of linear alkyl
benzene sulfonate, methylester sulfonate, paraffin
sulfonate, or a mixture of these; (ii) granulating said
high active paste to form agglomerates in a high shear
mixer/granulator with an effective amount of detergent
~B~
4a ~ 8 ~ ~
powders; and (iii) adding a dye, in an amount of from 0.1
to 20 ppm, based on the weight of the high active paste, by
mixing the dye with the high active paste in step (i), or by
pumping or by spraying the dye into the high shear
mixer/granulator in step (ii).
The invention also relates to a high active detergent
paste composition for use as an intermediate in a process
for the manufacture of a granular detergent, comprising a
dye characterized in that: said paste composition comprises
at least 60% by weight of salts of anionic surface active
agents, and that the paste composition has a viscosity of at
least 10 Pa.s to 10.000 Pa.s, when measured at a temperature
of 70~C and a shear rate of 25 s-l; and between 5 and 40% by
weight of the paste composition of water; and wherein said
dye is present at a level of from 0.1 to 20 ppm based on the
weight of the paste composition.
~1~02~5
~' ' 94/02574 P ~ /US93/05888
",,_
DETAILED DESCRIPTION OF THE INVENTION
It has been found that the incorporation of certain
dyes and optical brighteners into granules made by an
agglomeration process can give very good colour to the
detergent granule when fresh, and colour characteristics
which are maintained, or even improve upon storage.
The dye or optical brightener is preferably added to
the composition either before or during the agglomeration
process, preferably in a liquid form. A preferred
embodiment of this invention is to use either an aqueous
solution or in an organic carrier medium. In a most
preferred embodiment the organic carrier is a nonionic
surfactant or polyethylene glycol.
MANUFACTURE OF HIGH ACTIVE DETERGENT GRANULES
The granules of the present invention are made by
mixing a high active paste comprising the salts of anionic
surfactants with detergent powders in a high shear mixer
(agglomerator). The effect of the mixer is firstly to
fluidise the powder and then to rapidly disperse the
surfactant paste into this fluidised powder. The resulting
mixture remains in substantially discrete particles at all
time. It is not allowed to form into a dough which would
cause the high shear mixer to block. Inside the mixer a
fine dispersion mixing and granulation process takes place
under the influence of cutting and mixing tools mounted on
a shaft. Suitable paste compositions and processes are
described in more detail hereinbelow.
The re~llting particles are high in surfactant activity and
high in bulk density, but still have good flow and non-
caking characteristics. Preferably the surfactant activity
is greater than 40% by weight of the particles, and the
bulk density is at least 600 g/l.
SUBSTITUTE SHEET
W094/02574 2 ~ 5 PCT/US93/05888
-
The dye or optical brightener, when it is in a liquid
form may be either premixed with the high active detergent
paste by means of a batch mix tank or continuously into an
extruder or into a neutralisation loop, or it may be
sprayed or pumped directly into the high shear mixer where
it will be dispersed into the particles formed therein. In
a particularly preferred process, the dye or optical
brightener is pumped directly into the neutralisation loop
in which the acid forms of the surfactant are being
neutralised.
SUITABLE DYES AND OPTICAL BRIGHTENERS
Suitable dyes and optical brighteners for the present
invention are those that emit light in the violet or blue
range of the spectrum. For the present invention, it is
preferred that the light emitted by these dyes lies mostly
(at least 70%) in the region of visible light below 500nm
wavelength. Examples of useful dyes include Levanyl Violet
BNZ (Trade Name) and Special Fast Blue G FW Ground (Trade
Name), both supplied by Bayer AG.
Preferred optical brighteners are chosen from the sodium
salts of:
4,4'-bis-(2-diethanolamino-4-anilino-s-triazin-6-ylamino)
stilbene-2:2' disulphonate
4,4'-bis-(2-morpholino-4-anilino-s-triazin-6-ylamino)
stilbene-2:2' disulphonate
4,4'-bis-(2,4-dianilino-s-triazin-6-ylamino) stilbene-2:2'
disulphonate
4',4''-bis-(2,4-dianilino-s-triazin-6-ylamino) stilbene-2-
sulphonate
4,4'-bis-(2-anilino-4-(N-methyl N-2-hydroxyethylamino)-s-
triazin-6-ylamino) stilbene-2,2' disulphonate
4,4'-bis-(4-phenyl-2,1,3-triazol-2-yl) stilbene-2,2'
disulphonate
SUBSTITUTE SHEET
2 ~ 5
~ ~94/02574 PCT/US93/05888
,.......
4,4'-bis-(2-anilino-4-(1-methyl-2-hydroxyethylamino)-s-
triazin-6-ylamino) stilbene-2,2' disulphonate
4,4-bis (2-sulphostyryl) biphenyl
4,4-bis (4-chloro-3-sulphostyryl) biphenyl
Other optical brighteners which are also preferred for use
in the present invention include the derivatives of bis-
benzoxazolyl and 1-3-diphenyl-2-pyrazoline.
The levels of dyes used in the detergent paste is less
than 20ppm, preferably from 0.1 to 20 ppm. (These levels
are referred to as parts per million of pure dye, although
normally such dyes are supplied as solutions).
The level of optical brightener in the surfactant
paste is generally less than 5% and preferably less than
2%. The level of optical brightener in the granular
detergent component or composition is typically less than
2%, preferably less than 1%.
The Pastes
One or various aqueous pastes of the salts of anionic
surfactants is preferred for use in the present invention,
preferably the sodium salt of the anionic surfactant. In a
preferred embodiment, the anionic surfactant is preferably
as concentrated as possible, (that is, with the lowest
possible moisture content possible that allows it to flow
in the manner of a liquid) so that it can be pumped at
temperatures at which it remains stable. While granulation
using various pure or mixed surfactants is known, for the
present invention to be of practical use in industry and to
result in particles of adequate physical properties to be
incorporated into granular detergents, an anionic
surfactant must be part of the paste in a concentration of
above 40%, preferably from 40-95%, and most preferably from
60%-95%.
SUBSTITUTE Sl~.EET
W094/02574 ~ 2 ~ a PCT/US93/05888
It is preferred that the moisture in the surfactant
aqueous paste is as low as possible, while maintaining
paste fluidity, since low moisture leads to a higher
concentration of the surfactant in the finished particle.
Preferably the paste contains between 5 and 40% water, more
preferably between 5 and 30% water and most preferably
between 5 and 20% water. A highly attractive mode of
operation for lowering the moisture of the paste prior to
entering the agglomerator without problems with very high
viscosities is the installation, in line, of an atmospheric
or a vacuum flash drier whose outlet is connected to the
agglomerator.
It is preferable to use high active surfactant pastes
to minimize the total water level in the system during
mixing, granulating and drying. Lower water levels allow
for: (1) a higher active surfactant to builder ratio, e.g.,
1:1; (2) higher levels of other liquids in the formula
without causing dough or granular stickiness; (3) less
cooling, due to higher allowable granulation temperatures;
and (4) less granular drying to meet final moisture limits.
Two important parameters of the surfactant pastes
which can affect the mixing and granulation step are the
paste temperature and viscosity. Viscosity is a function,
among others, of concentration and temperature, with a
range in this application from about 10 Pa.s to 10,000
Pa.s. Preferably, the viscosity of the paste entering the
system is from about 20 to about 100 Pa.s. and more
preferably from about 30 to about 70 Pa.s. The viscosity
of the paste of this invention is measured at a temperature
of 70~C and at a shear rate of 25s-1.
The paste can be introduced into the mixer at an
initial temperature between its softening point (generally
in the range of 40-60~C) and its degradation point
(depending on the chemical nature of the paste, e.g. alkyl
St~ B~iTITl~
~40285
~'~'94/02574 PCT/US93/05888
,,_
sulphate pastes tend to degrade above 75-85OC). High
temperatures reduce viscosity simplifying the pumping of
the paste but result in lower active agglomerates. The use
of in-line moisture reduction steps (e.g. flash drying),
however, require the use of higher temperatures (above
100~C). In the present invention, the activity of the
agglomerates is maintained high due to the elimination of
moisture.
The introduction of the paste into the mixer can be
done in many ways, from simply pouring to high pressure
pumping through small holes at the end of the pipe, before
the entrance to the mixer. While all these ways are viable
to manufacture agglomerates with good physical properties,
it has been found that in a preferred embodiment of the
present invention the extrusion of the paste results in a
better distribution in the mixer which improves the yield
of particles with the desired size. The use of high
pumping pressures prior to the entrance in the mixer
results in an increased activity in the final agglomerates.
By combining both effects, and introducing the paste
through holes (extrusion) small enough to allow the desired
flow rate but that keep the pumping pressure to a maximum
feasible in the system, highly advantageous results are
achieved.
Hiqh Active Surfactant Paste
The activity of the aqueous surfactant paste is at
least 40% and can go up to about 95%; preferred activities
are : 60-95% and 65-80%. The balance of the paste is
primarily water but can include various processing aids.
At the higher active concentrations, little or no builder
is required for cold granulation of the paste. The
resultant concentrated surfactant granules can be added to
dry builders or powders or used in conventional
agglomeration operations. The aqueous surfactant paste
SUBSTlTUTE SHEET
W094/02574 ~1 4 ~ ~ 8 5 PCT/US93/05888
contains an organic surfactant selected from the group
consisting of anionic, zwitterionic, ampholytic and
cationic surfactants, and mixtures thereof. Anionic
surfactants are preferred. Nonionic surfactants are used
as secondary surfactants or processing aids, or as the
organic carrier for the optical brightener, and are not
included herein as an "active" surfactant. Surfactants
useful herein are listed in U.S. Pat. No. 3,664,961,
Norris, issued May 23, 1972, and in U.S. Pat. No.
3,919,678, Laughlin et al., issued Dec. 30, 1975. Useful
cationic surfactants also include those described in U.S.
Pat. No. 4,222,905, Cockrell, issued Sept. 16, 1980, and in
U.S. Pat. 4,239,659, Murphy, issued Dec. 16, 1980.
However, cationic surfactants are generally less compatible
with the aluminosilicate materials herein, and thus are
preferably used at low levels, if at all, in the present
compositions. The following are representative examples of
surfactants useful in the present compositions.
Water-soluble salts of the higher fatty acids, i.e.,
"soaps", are useful anionic surfactants in the compositions
herein. This includes alkali metal soaps such as the
sodium, potassium, ammonium, and alkylammonium salts of
higher fatty acids containing from about 8 to about 24
carbon atoms, and preferably from about 12 to about 18
carbon atoms. Soaps can be made by direct saponification
of fats and oils or by the neutralization of free fatty
acids. Particularly useful are the sodium and potassium
salts of the mixtures of fatty acids derived from coconut
oil and tallow, i.e., sodium or potassium tallow and
coconut soap.
Useful anionic surfactants also include the water-
soluble salts, preferably the alkali metal, ammonium and
alkylolammonium salts, of organic sulfuric reaction
products having in their molecular structure an alkyl group
containing from about 10 to about 20 carbon atoms and a
SUBSTITUTE SHEET
2~4~285
~--94/02574 PCT/US93/05888
1 1
sulfonic acid or sulfuric acid ester group. (Included in
the term "alkyl" is the alkyl portion of acyl groups.)
Examples of this group of synthetic surfactants are the
sodium and potassium alkyl sulfates, especially those
obtained by sulfating the higher alcohols (C8-C18 carbon
atoms) such as those produced by reducing the glycerides of
tallow or coconut oil; and the sodium and potassium alkyl
benzene sulfonates in which the alkyl group contains from
about g to about 15 carbon atoms, in straight or branched
chain configuration, e.g., those of the type described in
U.S. Pat. Nos. 2,220,099 and 2,477,383. Especially
valuable are linear straight chain alkyl benzene sulfonates
in which the average number of carbon atoms in the alkyl
group is from about 11 to 13, abbreviated as Cll-C13 LAS.
Other anionic surfactants herein are the sodium alkyl
glyceryl ether sulfonates, especially those ethers of
higher alcohols derived from tallow and coconut oil; sodium
coconut oil fatty acid monoglyceride sulfonates and
sulfates; sodium or potassium salts of alkyl phenol
ethylene oxide ether sulfates containing from about 1 to
about 10 units of ethylene oxide per molecule and wherein
the alkyl groups contain from about 8 to about 12 carbon
atoms; and sodium or potassium salts of alkyl ethylene
oxide ether sulfates containing from about 1 to about 10
units of ethylene oxide per molecule and wherein the alkyl
group contains from about 10 to about 20 carbon atoms.
Other useful anionic surfactants herein include the
water-soluble salts of esters of alpha-sulfonated fatty
acids containing from about 6 to 20 carbon atoms in the
fatty acid group and from about 1 to 10 carbon atoms in the
ester group; water-soluble salts of 2-acyloxy-alkane-1-
sulfonic acids containing from about 2 to 9 carbon atoms in
the acyl group and from about 9 to about 23 carbon atoms in
the alkane moiety; alkyl ether sulfates containing from
about 10 to 20 carbon atoms in the alkyl group and from
SUE3STITUTE SHEET
W094/02574 2 1 ~ O ~ ~ 5 12 PCT/US93/05888
about 1 to 30 moles of ethylene oxide; watersoluble salts
of olefin sulfonates containing from about 12 to 24 carbon
atoms; and beta-alkyloxy alkane sulfonates containing from
about 1 to 3 carbon atoms in the alkyl group and from about
8 to about 20 carbon atoms in the alkane moiety. Although
the acid salts are typically discussed and used, the acid
neutralization can be performed as part of the fine
dispersion mixing step.
The present invention has been found to be
particularly useful when the anionic surfactant paste
comprises surfactants which are particularly vulnerable to
discoloration, such as those pastes comprising at least 5%
by weight of linear alkyl benzene sulphonate, methyl ester
sulphonate or paraffin sulphonate, or a mixture of these.
The preferred anionic surfactant pastes are mixtures
of linear or branched alkylbenzene sulfonates having an
alkyl of 10-16 carbon atoms and alkyl sulfates having an
alkyl of 10-18 carbon atoms. These pastes are usually
produced by reacting a liquid organic material with sulfur
trioxide to produce a sulfonic or sulfuric acid and then
neutralizing the acid to produce a salt of that acid. The
salt is the surfactant paste discussed throughout this
document. The sodium salt is preferred due to end
performance benefits and cost of NaOH vs. other
neutralizing agents, but is not required as other agents
such as KOH may be used.
Water-soluble nonionic surfactants are also useful as
secondary surfactant in the compositions of the invention.
Indeed, preferred processes use anionic/nonionic blends. A
particularly preferred paste comprises a blend of nonionic
and anionic surfactants having a ratio of from about 0.01:1
to about 1:1, more preferably about 0.05:1. Nonionics can
be used up to an equal amount of the primary organic
surfactant. Such nonionic materials include compounds
SUBSTITUTE SHEET
8 5
~-94/02574 PCT/US93/05888
."_
13
produced by the condensation of alkylene oxide groups
(hydrophilic in nature) with an organic hydrophobic
compound, which may be aliphatic or alkyl aromatic in
nature. The length of the polyoxyalkylene group which is
condensed with any particular hydrophobic group can be
readily adjusted to yield a water-soluble compound having
the desired degree of balance between hydrophilic and
hydrophobic elements.
Suitable nonionic surfactants include the polyethylene
oxide condensates of alkyl phenols, e.g., the condensation
products of alkyl phenols having an alkyl group containing
from about 6 to 16 carbon atoms, in either a straight chain
or branched chain configuration, with from about 4 to 25
moles of ethylene oxide per mole of alkyl phenol and alkyl
glucose amides.
Preferred nonionics are the water-soluble condensation
products of aliphatic alcohols containing from 8 to Z2
carbon atoms, in either straight chain or branched
configuration, with from 4 to 100 moles of ethylene oxide
per mole of alcohol. Particularly preferred are the
condensation products of alcohols having an alkyl group
containing from about 9 to 15 carbon atoms with from about
4 to 80 moles of ethylene oxide per mole of alcohol; and
condensation products of propylene glycol with ethylene
oxide.
Semi-polar nonionic surfactants include water-soluble
amine oxides containing one alkyl moiety of from about 10
to 18 carbon atoms and 2 moieties selected from the group
consisting of alkyl groups and hydroxyalkyl groups
containing from 1 to about 3 carbon atoms; water-soluble
phosphine oxides containing one alkyl moiety of about 10 to
18 carbon atoms and 2 moieties selected from the group
consisting of alkyl groups and hydroxyalkyl groups
containing from about l to 3 carbon atoms; and water-
SUBSTITUTE SHEET
W094/02574 2 1 4 ~ 2 8 5 PCT/US93/05888
soluble sulfoxides containing one alkyl moiety of fromabout 10 to 18 carbon atoms and a moiety selected from the
group consisting of alkyl and hydroxyalkyl moieties of from
about 1 to 3 carbon atoms.
Ampholytic surfactants include derivatives of
aliphatic or aliphatic derivatives of heterocyclic
secondary and tertiary amines in which the aliphatic moiety
can be either straight or branched chain and wherein one of
the aliphatic substituents contains from about 8 to 18
carbon atoms and at least one aliphatic substituent
contains an anionic water-solubilizing group.
Zwitterionic surfactants include derivatives of
aliphatic quaternary ammonium phosphonium, and sulfonium
compounds in which one of the aliphatic substituents
contains from about 8 to 18 carbon atoms.
Particularly preferred surfactants herein include
linear alkylbenzene sulfonates containing from about 11 to
14 carbon atoms in the alkyl group; tallow alkyl sulfates;
coconutalkyl glyceryl ether sulfonates; alkyl ether
sulfates wherein the alkyl moiety contains from about 14 to
18 carbon atoms and wherein the average degree of
ethoxylation is from about 1 to 4; olefin or paraffin
sulfonates containing from about 14 to 16 carbon atoms;
alkyldimethylamine oxides wherein the alkyl group contains
from about 11 to 16 carbon atoms; alkyldimethylammonio
propane sulfonates and alkyldimethylammonio hydroxy propane
sulfonates wherein the alkyl group contains from about 14
to 18 carbon atoms; soaps of higher fatty acids containing
from about 12 to 18 carbon atoms; condensation products of
C9-C15 alcohols with from about 3 to 8 moles of ethylene
oxide, and mixtures thereof.
Useful cationic surfactants include water-soluble
quaternary ammonium compounds of the form R4R5R6R7N+X-,
SUBSTITUTE SHEET
21A0~8~
~ '94/02574 ~ PC~r/US93/05888
',._ , :
wherein R4 is alkyl having from 10 to 20, preferably from
12-18 carbon atoms, and R5, R6 and R7 are each Cl to C7
alkyl preferably methyl; X~ is an anion, e.g. chloride.
Examples of such trimethyl ammonium compounds include C12_
14 alkyl trimethyl ammonium chloride and cocalkyl trimethyl
ammonium methosulfate. Other cationic surfactants including
coline esters may be used.
Specific preferred surfactants for use herein include:
sodium linear C11-C13 alkylbenzene sulfonate; alpha-olefin
sulphonates; triethanolammonium C11-C13 alkylbenzene
sulfonate; alkyl sulfates, (tallow, coconut, palm,
synthetic origins, e.g. C45, etc.); sodium alkyl sulfates;
methyl ester sulphonate; sodium coconut alkyl glyceryl
ether sulfonate; the sodium salt of a sulfated condensation
product of a tallow alcohol with about 4 moles of ethylene
oxide; the condensation product of a coconut fatty alcohol
with about 6 moles of ethylene oxide; the condensation
product of tallow fatty alcohol with about 11 moles of
ethylene oxide; the condensation of a fatty alcohol
containing from about 14 to about 15 carbon atoms with
about 7 moles of ethylene oxide; the condensation product
of a C12-C13 fatty alcohol with about 3 moles of ethylene
oxide; 3-(N,N-dimethyl-N-coconutalkylammonio)-2-
hydroxypropane-l-sulfonate; 3-(N,N-dimethyl-N-
coconutalkylammonio)-propane-l-sulfonate; 6- (N-
dodecylbenzyl-N,N-dimethylammonio) hexanoate;
dodecyldimethylamine oxide; coconutalkyldimethylamine
oxide; and the water-soluble sodium and potassium salts of
coconut and tallow fatty acids.
(As used herein, the term "surfactant" means non-
nonionic surfactants, unless otherwise specified. The
ratio of the surfactant active (excluding the nonionic(s))
to dry detergent builder or powder ranges from 0.005:1 to
19:1, preferably from 0.05:1 to 10:1, and more preferably
from 0.1:1 to 5:1. Even more preferred said surfactant
SUBSTITUTE SHEET
W094/02574 2 1 ~ ~ 2 i 5 PCT/US93/05888
16
active to builder ratios are 0.15:1 to 1:1; and 0.2:1 to
0.5:1).
Powder stream
Although the preferred embodiment of the process of
the present invention involves introduction of the anionic
surfactant in via pastes as described above, it is possible
to have a certain amount via the powder stream, for example
in the form of blown powder. In these embodiments, it is
necessary that the stickiness and moisture of the powder
stream be kept at low levels, thus preventing increased
"loading" of the anionic surfactant and, thus, the
production of agglomerates with too high of a concentration
of surfactant. The liquid stream of a preferred
agglomeration process can also be used to introduce other
surfactants and/or polymers. This can be done by premixing
the surfactant into one liquid stream or, alternatively by
introducing various streams in the agglomerator. These two
process embodiments may produce differences in the
properties of the finished particles (dispensing, gelling,
rate of dissolution, etc.), particularly, if mixed
surfactants are allowed to form prior to particle
formation. These differences can then be exploited to the
advantage of the intended application for each preferred
process.
It has also been observed that by using the presently
described technology, it has been possible to incorporate
higher levels of certain chemicals (e.g. nonionic, citric
acid) in the final formula than via any other known
processing route without detrimental effects to some key
properties of the matrix (caking, compression, etc.).
SUBSTITIJTE SHEET
2 1 ~
94/02574 PCT/US93/05888
The Fine DisPersion Mixing and Granulation
The term "fine dispersion mixing and/or granulation,"
as used herein, means mixing and/or granulation of the
mixture in a fine dispersion mixer at a blade tip speed of
from about 5m/sec. to about 50 m/sec., unless otherwise
specified. The total residence time of the mixing and
granulation process is preferably in the order of from 0.1
to 10 minutes, more preferably 0.1-5 and most preferably
0.2-4 minutes. The more preferred mixing and granulation
tip speeds are about 10-45 m/sec. and about 15-40 m/sec.
Any apparatus, plants or units suitable for the
processing of surfactants can be used for carrying out the
process according to the invention. Suitable apparatus
includes, for example, falling film sulphonating reactors,
digestion tanks, esterification reactors, etc. For mixing/
agglomeration any of a number of mixers/agglomerators can
be used. In one preferred embodiment, the process of the
invention is continuously carried out. Especially
preferred are mixers of the FukaeR FS-G series manufactured
by Fukae Powtech Kogyo Co., Japan; this apparatus is
essentially in the form of a bowl-shaped vessel accessible
via a top port, provided near its base with a stirrer
having a substantially vertical axis, and a cutter
positioned on a side wall. The stirrer and cutter may be
operated independently of one another and at separately
variable speeds. The vessel can be fitted with a cooling
jacket or, if necessary, a cryogenic unit.
Other similar mixers found to be suitable for use in
~he process of the invention include DiosnaR V series ex
Dierks & Sohne, Germany; and the Pharma MatrixR ex T K
Fielder Ltd., England. Other mixers believed to be
suitable for use in the process of the invention are the
FujiR VG-C series ex Fuji Sangyo Co., Japan; and the RotoR
ex Zanchetta & Co srl, Italy.
SUBSTITUTE SHEET
W094/02574 21~ ~ 2 8 .~ PCT/US93/OS888
18
Other preferred suitable equipment can include
EirichR, series RV, manufactured by Gustau Eirich Hardheim,
Germany; LodigeR, series FM for batch mixing, series Baud
KM for continuous mixing/agglomeration, manufactured by
Lodige Machinenbau GmbH, Paderborn Germany; DraisR T160
series, manufactured by Drais Werke GmbH, Mannheim Germany;
and WinkworthR RT 25 series, manufactured by Winkworth
Machinery Ltd., Berkshire, England.
The Littleford Mixer, Model #FM-130-D-12, with
internal chopping blades and the Cuisinart Food Processor,
Model #DCX-Plus, with 7.75 inch (19.7 cm) blades are two
examples of suitable mixers. Any other mixer with fine
dispersion mixing and granulation capability and having a
residence time in the order of 0.1 to 10 minutes can be
used. The "turbine-type" impeller mixer, having several
blades on an axis of rotation, is preferred. The invention
can be practiced as a batch or a continuous process.
Operatinq Temperatures
Preferred operating temperatures should also be as low
as possible since this leads to a higher surfactant
concentration in the finished particle. Preferably the
temperature during the agglomeration is less than 80~C,
more preferably between 0~ and 70~C, even more preferably
between 10 and 60~C and most preferably between 20 and
50~C. Lower operating temperatures useful in the process
of the present invention may be achieved by a variety of
methods known in the art such as nitrogen cooling, cool
water jacketing of the equipment, addition of solid CO2,
and the like; with a preferred method being solid CO2, and
the most preferred method being nitrogen cooling.
SUBSTITUTE SHEET
~ 4~8~j
~-~94/02574 PCT/US93/05888
",~.
19
A highly attractive opinion in a preferred embodiment
of the present invention to further increase the
concentration of surfactant in the final particle, is
accomplished by the addition to a liquid stream containing
the anionic surfactant and/or other surfactant, of other
elements that result in increases in viscosity and/or
melting point and/or decrease the stickiness of the paste.
In a preferred embodiment of the process of the present
invention the addition of these elements can be done in
line as the paste is pumped into the agglomerator. Example
of these elements can be various powders, described in more
detail later herein.
Final Agqlomerate Com~osition
The present invention produces granules of high
density for use in detergent compositions. A preferred
composition of the final agglomerate for incorporation into
granular detergents has a high surfactant concentration.
By increasing the concentration of surfactant, the
particles/agglomerates made by the present invention are
more suitable for a variety of different formulations.
These high surfactants containing particle agglomerates
require fewer finishing techniques to reach the final
agglomerates, thus freeing up large amounts of processing
aids (inorganic powders, etc.) that can be used in other
processing steps of the overall detergent manufacturing
process (spray drying, dusting off, etc).
The granules made according to the present invention
are large, low dust and free flowing, and preferably have a
bulk density of up to about 1.0 g/cc, more preferably from
about 0.6 to about 0.8 g/cc. The weight average particle
size of the particles of this invention are from about 200
to about 1000 microns. The preferred granules so formed
have a particle size range of from 200 to 2000 microns.
The more preferred granulation temperatures range from
SUBSTITUTE SHEET
W094/02574 2 1 4 ~ 2 ~ ~j PCT/US93/05888
about 10~C to about 60~C, and most preferably from about
20~C to about 50~C.
Drying
The desired moisture content of the free flowing
granules of this invention can be adjusted to levels
adequate for the intended application by drying in
conventional powder drying equipment such as fluid bed
dryers. If a hot air fluid bed dryer is used, care must be
exercised to avoid degradation of heat sensitive components
of the granules. It is also advantageous to have a cooling
step prior to large scale storage. This step can also be
done in a conventional fluid bed operated with cool air.
The drying/cooling of the agglomerates can also be done in
any other equipment suitable for powder drying such as
rotary dryers, etc.
For detergent applications, the final moisture of the
agglomerates needs to be maintained below levels at which
the agglomerates can be stored and transported in bulk.
The exact moisture level depends on the composition of the
agglomerate but is typically achieved at levels of 1-8%
free water (i.e. water not associated to any crystalline
species in the agglomerate) and most typically at 1-4%.
~eterqency Builders and Powders
Any compatible detergency builder or combination of
builders or powder can be used in the process and
compositions of the present invention.
The detergent compositions herein can contain
crystalline aluminosilicate ion exchange material of the
formula
NaZ[(Al02)z-(sio2)y]-xH2o
SUBSTITUTE SHEET
21 40285
~' 94/02574 PCT/US93/05888
21
wherein z and y are at least about 6, the molar ratio of z
to y is from about 1.0 to about 0.4 and z is from about 10
to about 264. Amorphous hydrated aluminosilicate materials
useful herein have the empirical formula
Mz(zAlO2-ySiO2)
wherein M is sodium, potassium, ammonium or substituted
ammonium, z is from about 0.5 to about 2 and y is 1, said
material having a magnesium ion exchange capacity of at
least about 50 milligram equivalents of CaCO3 hardness per
gram of anhydrous aluminosilicate. Hydrated sodium Zeolite
A with a particle size of from about 1 to 10 microns is
preferred.
The aluminosilicate ion exchange builder materials
herein are in hydrated form and contain from about 10% to
about 28~ of water by weight if crystalline, and
potentially even higher amounts of water if amorphous.
Highly preferred crystalline aluminosilicate ion exchange
materials contain from about 18% to about 22% water in
their crystal matrix. The crystalline aluminosilicate ion
exchange materials are further characterized by a particle
size diameter of from about 0.1 micron to about 10 microns.
Amorphous materials are often smaller, e.g., down to less
than about 0.01 micron. Preferred ion exchange materials
have a particle size diameter of from about 0.2 micron to
about 4 microns. The term "particle size diameter" herein
represents the average particle size diameter by weight of
a given ion exchange material as determined by conventional
analytical techniques such as, for example, microscopic
determination utilizing a scanning electron microscope.
The crystalline aluminosilicate ion exchange materials
herein are usually further characterized by their calcium
ion exchange capacity, which is at least about 200 mg
equivalent of CaCO3 water hardness/g of aluminosilicate,
calculated on an anhydrous basis, and which generally is in
the range of from about 300 mg eq./g to about 352 mg eq./g.
The a~uminosilicate ion exchange materials herein are still
Sl~BSTIT~JTE S~4EET
22
further characterized by their calcium ion exchange rate
which is at least about 2 grains Ca++/gallon/minute/gram/
gallon of aluminosilicate (anhydrous basis), and generally
lies within the range of from about 2 grains/gallon/minute/
gram/gallon to about 6 grains/gallon/minute/gram/gallon,
based on calcium ion hardness. Optimum aluminosilicate for
builder purposes exhibit a calcium ion exchange rate of at
least about 4 grains/gallon/minute/gram/gallon.
The amorphous aluminosilicate ion exchange materials
usually have a Mg++ exchange of at least about 50 mg eq.
CaCO3/g (12 mg Mg++/g) and a Mg++ exchange rate of at least
about 1 grain/gallon/minute/gram/gallon. Amorphous
materials do not exhibit an observable diffraction pattern
when examined by Cu radiation (1.54 Angstrom Units).
Aluminosilicate ion exchange materials useful in the
practice of this invention are commercially available. The
aluminosilicates useful in this invention can be crystalline
or amorphous in structure and can be naturally occurring
aluminosilicates or synthetically derived. A method for
producing aluminosilicate ion exchange materials is
discussed in U.S. Pat. No. 3,985,669, Krummel et al., issued
Oct. 12, 1976. Preferred synthetic crystalline
aluminosilicate ion exchange materials useful herein are
available under the designations Zeolite A, Zeolite B, and
Zeolite X. In an especially preferred embodiment, the
crystalline aluminosilicate ion exchange material has the
formula
Nal2 [ (A1~2) 12 (Sio2) 12] ' XH20
wherein x is from about 20 to about 30, especially about 27
and has a particle size generally less than about 5 microns.
The granular detergents of the present invention can
contain neutral or alkaline salts which have a pH in
21~02~5
~ 94/02574 PCT/US93/05888
~, ~
23
solution of seven or greater, and can be either organic or
inorganic in nature. The builder salt assists in providing
the desired density and bulk to the detergent granules
herein. While some of the salts are inert, many of them
also function as detergency builder materials in the
laundering solution.
Examples of neutral water-soluble salts include the
alkali metal, ammonium or substituted ammonium chlorides,
fluorides and sulfates. The alkali metal, and especially
sodium, salts of the above are preferred. Sodium sulfate
is typically used in detergent granules and is a
particularly preferred salt. Citric acid and, in general,
any other organic or inorganic acid may be incorporated
into the granular detergents of the present invention as
long as it is chemically compatible with the rest of the
agglomerate composition.
Other useful water-soluble salts include the compounds
commonly known as detergent builder materials. Builders
are generally selected from the various water-soluble,
alkali metal, ammonium or substituted ammonium phosphates,
polyphosphates, phosphonates, polyphosphonates, carbonates,
silicates, borates, and polyhyroxysulfonates. Preferred
are the alkali metal, especially sodium, salts of the
above.
Specific examples of inorganic phosphate builders are
sodium and potassium tripolyphosphate, pyrophosphate,
polymeric metaphosphate having a degree of polymerization
of from about 6 to 21, and orthophosphate. Examples of
polyphosphonate builders are the sodium and potassium salts
of ethylene diphosphonic acid, the sodium and potassium
salts of ethane 1-hydroxy-1,1-diphosphonic acid and the
sodium and potassium salts of ethane, 1,1,2-triphosphonic
acid. Other phosphorus builder compounds are disclosed in
SUBSTITUTE SHEET
~ ~ 4 ~
._.
24
U.S. Pat. Nos. 3,159,581; 3,213,030; 3,422,021; 3,422,137;
3,400,176 and 3,400,148.
-
Examples of nonphosphorus, inorganic builders aresodium and potassium carbonate, bicarbonate,
sesquicarbonate, tetraborate decahydrate, and silicate
having a molar ratio of SiO2 to alkali metal oxide of from
about 0.5 to about 4.0, preferably from about 1.0 to about
2.4. The compositions made by the process of the present
invention does not require excess carbonate for processing,
and preferably does not contain over 2~ finely divided
calcium carbonate as disclosed in U.S. Pat. No. 4,196,093,
Clarke et al., issued Apr. 1, 1980, and is preferably free
of the latter.
As mentioned above powders normally used in detergents
such as zeolite, carbonate, silica, silicate, citrate,
phosphate, perborate, etc. and process acids such as starch,
can be used in preferred embodiments of the present
invention.
Polymers
Also useful are various organic polymers, some of which
also may function as builders to improve detergency.
Included among such polymers may be mentioned sodium
carboxy-lower alkyl celluloses, sodium lower alkyl
celluloses and sodium hydroxy-lower alkyl celluloses, such
as sodium carboxymethyl cellulose, sodium methyl cellulose
and sodium hydroxypropyl cellulose, polyvinyl alcohols
(which often also include some polyvinyl acetate),
polyacrylamides, polyacrylates and various copolymers, such
as those of maleic and acrylic acids. Molecular weights for
such polymers vary widely but most are within the range of
2,000 to 100,000.
~4 D~
~- ~94/02574. PCT/US93/05888
.... .
Polymeric polycarboxylate builders are set forth in
U.S. Patent 3,308,067, Diehl, issued March 7, 1967. Such
materials include the water-soluble salts of homo-and
copolymers of aliphatic carboxylic acids such as maleic
acid, itaconic acid, mesaconic acid, fumaric acid, aconitic
acid, citraconic acid and methylenemalonic acid.
OPtionals
Other ingredients commonly used in detergent
compositions can be included in the compositions of the
present invention. These include flow aids, color
speckles, bleaching agents and bleach activators, suds
boosters or suds suppressors, antitarnish and anticorrosion
agents, soil suspending agents, soil release agents,
fillers, germicides, pH adjusting agents, nonbuilder
alkalinity sources, hydrotropes, enzymes, enzyme-
stabilizing agents, chelating agents and perfumes.
Particulate suds suppressors may also be incorporated
either directly in the agglomerates herein by way of the
powder stream into the agglomerating unit, or in the
finished composition by dry adding. Preferably the suds
suppressing activity of these particles is based on fatty
acids or silicones.
SUBSTITUTE SHEET
W094/02574 2 1 4 ~ ~ 8 S PCT/US93/05888
26
EXAMPLES
The terms "LAS" and "AS" as used herein mean,
respectively, "sodium lauryl benzene sulfonate" and "alkyl
sulfate." "MES" means sodium methyl ester sulphonate. The
terms like "C45" mean C14 and C15 alkyl, unless otherwise
specified. TAS means sodium tallow alkyl sulphate.
Dobanol 45E7 is a C14/C15 alcohol ethoxylate with 7 units
of ethylene oxide and is manufactured by Shell Co. AE3S
means sodium alkyl ether sulphate with an average of 3
ethoxy groups per molecule.
High active base granules (agglomerates) were made from a
high active surfactant paste and a powder mixture using a
small food processor (Braun ~TM] Multipractic Plus
Electronic de luxe).
The powder mixture consisted of
sodium silicate (3 Na) 11.5%
sodium carbonate 50.5%
carboxy methyl cellulose 1.6%
zeolite A 36.4%
The high active surfactant paste comprised l8% water, and a
total surfactant activity (including optical brightener,
when present) of 78%. The anionic surfactants were present
in the ratio of 74 : 24 : 2 of LAS : TAS : AE3S.
In each experiment, 300g of this powder mixture were
placed inside a mixer bowl and 110.5g of a the high active
paste was added at 50~C slowly while operating the mixer of
the food processor at the highest speed. After about 30
seconds, the cutter speed was reduced to a minimum level
and water was slowly added until granulation occurred,
resulting in particles with an average diameter between 400
microns and 600 microns. The wet agglomerates were then
dried for about 15 minutes in a fluid bed with an air inlet
S~JBST~ E S~
2:~4~285
~ 94/02574 PCT/US93/05888
~,,.~.
temperature of 60~C. The resulting equivalent relative
humidity (eRH) of the agglomerates was 10-15%.
In the following examples 1 to 5, different levels of
nonionic surfactant (Dobanol 45E7 [TM~ from Shell) and
optical brightener (4,4'-bis-{[2-morpholino-4-anilino-
1,3,5-triazin-6-yl~amino}stilbene-2,2'-disulphonate)* were
processed into the paste before the agglomeration in the
food processor. The resulting particles were measured for
colour.
* Colour Index Fluorescent Brightener No. 71 as published
by the Society of Dyers and Colorists and the American
Association of Textile Chemists and Colorists.
% Anionic Surfactants % ~Jon ~n ~ S~ acLa,-ls% B.i~l,lener
in high active paste in hi~h active paste in hi~h active paste
Example 1 76.8 0 1.2
Example 2 73.2 3.7 1.1
Example 3 70.0 7.0 1.0
Comp. Example 4 78.0 0 0
Comp. Example 5 70.9 7.1 0
In example 1, the powdered optical brightener was
thoroughly mixed for 15 minutes with the high active
surfactant paste inside a Drais (TM) kneader (Planetary
mixer and kneading machine type FH1.55 from Draiswerke
GmbH), kept at 50~C and with a slight vacuum to avoid
aerating the paste.
In examples 3 and 4 the powdered optical brightener was
first thoroughly dispersed in the nonionic surfactant at
50~C using a high speed mixer. This dispersion was then
mixed into the high active anionic surfactant paste in the
r same manner as example 1.
In comparative example 4 the paste was treated in a kneader
as in previous examples but no nonionic or brightener was
added.
SUBSTITUTE SHEET
~ 40285
W094/02574 PCT/US93/05888
28
In comparative example 5 the nonionic surfactant was mixed
with the anionic surfactant paste in a kneader but no
optical brightener was added.
In each example the agglomerates were sieved between Tyler
mesh 20 and Tyler mesh 35 to remove the fine and coarse
particles, the remaining fraction being assessed for colour
by the Hunter Lab method (Hunter, R.S. J.Opt.Soc.Amer 48
597 (1958)) using a commercially available Hunterlab
Color/Difference meter model D25-2 from Elscoserv N.V.
2~4~8S
~ ~ '94/02574 PCT/US93/05888
. ,,_
29
The colour readings of the agglomerates were:
Hunter Values
L a b
Example 1 92.2 0.0 5.5
Example 2 91.3 0.6 5.0
Example 3 90.8 1.2 4.6
Comp. Example 4 91.8 -0.4 6.9
Comp. Example 5 91.2 -0.4 7.6
It is known from consumer appearance tests that
agglomerates with low L values (<85%), and/or negative a
values (a<0) tending to be greenish, and/or high b values
(b>6) tending to be yellowish, are easy to pick out from
the granular composition and contribute to a poor product
appearance.
In this respect examples 1-3 containing optical
brightener processed as described, have the best colour. In
particular, examples 2 and 3 in which the brightener is
premixed with nonionic surfactant have superior colour
characteristics.
In examples 6 and 7, agglomerates were made in a
Loedige FM mixer/agglomerator.
The powder mixture consisted of:
sodium silicate (3 Na) 17.5%
sodium carbonate 32.5%
carboxy methyl cellulose 2.4%
zeolite A 47.6%
The high active surfactant paste comprised 18% water,
and a total surfactant activity (including dye solution,
SUBSTITUTE SHEEr
W094/02574 2 1 ~ 0 2 8 5 PCT/US93/0588~
when present) of 78%. The anionic surfactants were present
in the ratio of 74 : 24 : 2 of LAS : TAS : AE3S.
In both experiments 25.8kg of the powder mixture were
placed into the mixer/granulator along with 14.3kg of the
high active surfactant paste at 50~C. Both the ploughshares
and the choppers of the mixer/agglomerator were operated
for about 100 seconds, producing agglomerates with an
average particle size of 400-600 microns. The agglomerates
were dried in a fluid bed with air inlet temperature of
80~C for about 15 minutes after which they are cooled down
to 35~C using ambient air before discharge. The eRH of the
agglomerates is between 10% and 15%.
In example 6 a dye solution is prepared consisting of:
2 parts of Special Fast Blue G FW Ground (Acid blue 127/l)
supplied by Bayer UK Ltd at a concentration of 25%, and
1 part of Levanyl Violet BNZ (Pigment Violet 23) supplied
by Bayer UK Ltd at a concentration of 25%.
This dye mixture was then diluted to a 0.1% aqueous
solution before mixing with the high active surfactant
paste and subsequently processing into agglomerates in the
manner described above. 90ml of the 0.1% solution was mixed
with 15 kg of paste.
In each example the agglomerates were sieved between
Tyler mesh 20 and Tyler mesh 35 to remove the fine and
coarse particles, the remaining fraction being assessed for
colour by the Hunter Lab method (Hunter, R.S.
J.Opt.Soc.Amer 48 597 (1958)) using a commercially
available Hunterlab Color/Difference meter model D25-2 from
Elscoserv N.V.
The colour readings of the agglomerates was:
SUBSTITUTE Sl !EE:.
2 8 ~
~ . 94/02574 PC~r/US93/05888
.w_
Hunter Values
L a b
Example 6 (with dye) 87.4 -0.2 4.3
Comp. example 7 (no dye) 89.6 -0.5 9.4
Example 6 (with dye) has less of a yellow colour than
example 7 in which no dye has been added.
r
SUBSTITUTE SHEET
