Note: Descriptions are shown in the official language in which they were submitted.
WO~2/18603 P~T/US92/028~0
AGGLOMERATION OF HIGH ACTIVE PASTES TO FORM SURFACTANT
GRANULES USEFUL IN DETERGENT COMPOSITIONS . .:~
,~',: ,:-, ',
: ~ _ '',' ' ,
The present invention relates to a process for
preparing compositions comprising condensed detergent
granules.
BACKGROUND OF THE INVENTION
~" ~
` : Granular detergent compositions have so far been
: ; principally prepaxed~by~spray drying. In the spray drying
;~ process the:detergent componénts, such as surfactants and :~.
:builders, are~mixed with as much as::35-50% water to foxm a : .
slurry.~:The slurry obtained~is heated and spray dried,
WO92/18603 PCT/~S92/0288~
2 ~ 7 ;,~
whlch is expensive. A good agglomeration process, however,
could be less expensive.
Spray drying requires 30-~0 wt. % of the water to be
removed. The equipment used to produce spray dry is
expensive. The yranule obtained has goocl solubility but a
low bulk density, so the packing volume is large. Also,
the flow properties of the granule obtained by spray drying
are adversely affected by large surface irregularities, and
thus the granulate has a poor appearance. There are other
known disadvantages in preparing granular detergents by
spray drying.
. , ,
There are many prior art nonspray-drying processes
which produce detergent granules. They have drawbacks as
well. Most require more than one mixer and a separake
granulation operation. Others require ui~e of the acid form
of the surfactant to work. Some others require high
temperatures which degrade the starting materials. High
activa surfactant paste is avoided in these pxocesses ~
because of its stickiness. ~ -
. :, ' .
EP-A-O 345 090, puhlished December 6, 1989, disclos~s
a process for manufacturing particulate detergent
compositions comprising contacting detergent acid with
neutralizing agents and providing particulates by
contacting the detergent acid with a particulate
neutralizing agent or detergent salt with carrier in an
absorption zone.
EP-A O 349 201, published January 3, 1990, discloses a
process for preparing condensed detergent granules by
7 finely dispersing dry detergent builders and a high active
surfactant put into a uniform dough which is subsequently
chilled and granulated using fine dispersion to form
uniform, free flowing granular particles.
Ep~a 390 251, published October 3, l99O, discloses a
process f`or the continuous preparation of a granular
detergent or composition comprising steps of treating,
1: . .. :.
.~`! .:
WO92/18603 PCT/VS92/02880
2~ ~g~7
firstly, particulate starting material of detergent
surfactant and builders in a high-spead mixer, secondly in
a moc ~te-speed granulator/densifier and thirdly in a
drying/cooling apparatus, with the addition of powder in
the second or between the first and second step to reduce
the amount of oversize particles.
A. Davidsohn and B.M. Mildwidsky, Svnthet1c
Detergents, John Wiley ~ Sons 6th edition, 1978, discloses
general detergency teachings, including the manufacturing
of finished detergent products.
,'.
High shear and cold mixing processes per se are known,
but they require an extra grinding step or some other
action. E.g., some use a dry neutralization technique of
mixing an acid form of the surfactant with sodium
carbonate. See U.S. Pat. No. 4,515,707, Brooks, issued May
7, 1985; Japanese laid-open Appln. No. 183540/1983, Kao
Soap Co., Ltd., filed Sept. 30, 1983; and Japanese Sho. 61-
118500, Lion X.K., June 5, 1986. Typically, excess
car~onate is required t2-20 molar excess) to assure
reasonable conversion of the surfactant acids. Excess
carbonate adversely drives up the wash water pH to the very
alkaline range which can be undesirable, particularly for
some low-phosphate formulas.
.
The use of a surfactant acid generally requires
immediate use or cool temperature storage, for highly
reactive acids such as the alkyl sulfate acids are subject ;
ko degradation unless cooled, they tend to undergo
hydrolysis during storage, forming free sulfuric acid ~nd
alcohol. In practical terms, such prior art processes
require close-coupling of surfactant acid production with
granulation which requires an additional capital
investment.
A second route~ well known in the field and described
in the patent literature, is the in-situ neutralisation of
the anionic surfactant acid with caustic solutions (e.g. -;
,
,
W092/18603 PCT/US92/02880
21Q~7
50% NaOH) or caus~ic powders ~e.g. Na2CO3) right before or
in the course of the granulation step. In this situation,
precautions are needed to ensure complete neutralisation of
the acid to ~void undesirable effects on the rest of the
surfactant matrix upon storage/or during the wash. The
resulting particle is a highly dense granule which can be
incorporated into granular detergents.
While this second route uses lower temperatures and
less drastic shear conditions than crutching and spray -
drying, it has many limitations. On one side the need to
carry out a chemical reaction (neutralization) during or
right before the granulation step limits considerably the
range of processing conditions that can be used
~temperature, chemicals, etc.). The very low pH of the
anionic surfactant acid prevents the incorporation of
chemicals sensitive to these acidic conditions. But above i~
all, in the case of those anionic surfactants which are not
chemically stable in the acid form or physically unstabl~,
this process requires the close coupling of the
sulphation/sulphonation unit with the
neutralization/granulation step. This results in
considerable limitations in the logistics and/or the design
of the facilities for these processes as well as an
important increase in the complexity and difficulty of the
control systems for the overall process.
:', '~
The present invention brings solutions to the problems
mentioned above and provides with a more flexible and
versatile route to the processing of granular detergents.
The present in~ention is based on an agglomeration/
granulation step that is completely uncoupled from the
sulphation/sulphonation process. The basis of the
invention is the introduction of the anionic surfactant in
an aqueous, highly concentrated solution of its salt, most
preferably of its sodium salt. These high active (low
moisture) surfactant pastes are of a high viscosity but
remain pumpable at temperatures at which the surfactants
. ..:
WO~2/18603 PCT/US92/02~80
2 1 ~
are stable. This guarantees the ability to transport and
transfer the chemical from the manufacturing location to
the granulation site and to be able to have adequate
storage facilities prior to the formation of a particle.
For those cases where both the sulphation/sulphonation is
already immediately precPding the granulation step, it
provides the possibility to install intermediate buffer
tanks that simplifies the control of the whole unit. In
the case of some anionic surfactants or mixtures of them
where highly viscous liquid crystal phases occur, this
technology requires that either lower viscous phases can be
formed (e~g. neat phases) or that some viscosity modifiers
are used (e.g. hydrotrop~s).
An important object of the present invention is to
make a dense, concentrated detergent granular product by an
agglomeration process as opposed to a spray-drying process.
It is anoter object of the invention to provide for a
granular detergent product having a good solubility and
good dispersion properties, and improved dispensing from a
washing machine.
Other objects of the present invention will be
apparent in view of the following.
SUMMARY OF THE INVENTION
The present invention relates to an econom~cal process
for making a dense, concentrated detergent granular
product, and particularly, compositions comprising very
high activP condensed detergent granules.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. l shows a graph of viscosity versus shear rate for
a) a nil-surfactant slurry, comprising a relatively small
amount of zeolite.
b) a similar, typical detergent slurry containing
surfactant and a relatively high proportion of zeolite.
WO92/18603 PCT/US92/02X80
7 ~ ; ~
c) a nil-surfactant slurry comprising no zeolite at all.
` Fig. 2 shows the solubility of a spray-dried nil-
surfactant powder having a relatively low level of 2eolite,
compared to the solubility of the powder produced from a
surfactant-containing slurry.
DETAILED DESCRIPTION OF THE INVENTION
The present invention comprises a process for making a
free flowing granular detergent comprising : mixing an ~ `
effective amount or an aqueous surfactant paste having a
detergency activity of at least 40~ and an effective amount
of a dry detergency powder, said surfactant paste active
and builder or powder having a ratio of 0.05:l to l9:l to
form a mix; rapidly forming a uniform mixture from said mix
at a temperature of from about 0C to about 80C;
granulating said mixture into discrete detergent granules
using a high speed mixing at a tip speed of about 5-50 ;
m/sec; and wherein said surfactant paste is comprised of at
least one anionic surfactant, and any oth~r surfactants, if
present, are selected from the group of anionic, nonionic,
zwitterionic, ampholytic and cationic surfactants and ~ -
mixtures thereof; and wherein said mixing and granulating
are conducted simultaneously, or immediately sequentially.
:,,
The present invention is based on an agglomeration/
granulation step that is completely uncoupled from the
sulphation/sulphonation process. In one embodiment of the
present invention, the introduction of the anionic
surfactant in an aqueous, highly concentrated solution of
its salt, preferably its sodium salt. These high active
(and, preferably, low moisture) surfactant pastes are of a
high viscosity but remain pumpable at temperatures at which
the surfactants are stable. In other embodiments of the
present invention, anionic surfactants or mixtures
comprising at least one anionic surfactant, where highly
viscous liquid crystal phases occur~ requires that either
: , ' ' ':
: ' ~
-
WO92/18603 2 1 ~ PCT~us92/~28~Q
.`., ` ~
lower YiscoUs phases be formed or that some viscosity
modifiexs are used.
- In a further embodiment of the present invention, a
process ~or making a free flowing detergent composition is
provided, wherein the granulhted surfactants herein are
admixed with the remain~er of the detergent ingredients,
which are typically spray-dried into a blown powder from a
slurry. Preferably said slurry comprises between 15% and
55~ by weight of a builder, the spray-dried slurry being
mixed with the agglomerated surfactant. The viscosity of
the nil-surfactant slurry having low amounts of builder
(detergency powder), preferably zeolite, has been found to
b~ in the same range as the viscosity of aqueous slurries
comprising surfactant, at the same moisture content and in
the relevant shear-rate range. There~ore, spray-drying the
nil-surfactant slurry using pressure nozzles under standard
condi~ions is possible. The advantage of lower amounts o~
builder powder in the nil-surfactant slurry, is that
viscosity-increasing components such as polymers or minors,
can be included in the nil-surfactant slurry. Using
relatively low amounts of builder powder in the nil-
surfactant slurry, the main part of the total amount of
builder powder being used for agglomeration of the active
paste, provides space for the use of other admixed builders
such as layered silicate or citrate.
The spray-dried powder formed ~rom the nil-surfactant
slurry containing relatively little amounts of builder, has
good solubility compared to detergent compositions formed
by spray-drying a slurry containing surfactant.
By mixing the spray-dried nil surfactant powder with the
granulated actiue paste, and other dry ingredients such as
bleach, bleach activators, anti foaming agents, enzymes and
stabilizers, a finished product is obtained having good ~ -~
dispe~sing and dispersion properties in the wash solution.
Spray drying the aqueous nil-surfactant slurry comprising a
part o~ the total amount of builder used, results in a
powder havlng improved absorption properties compared to
WO92/1~603 PCT/~S92/02~80
2 ~ 7~ ~
the builder in its raw material state. Hereby larger
amounts of a non-ionic surfactant can be sprayed onto the
spray-dried nil surfactant slurry~
The Pastes
One or various aqueous pastes of the salts o* 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, w:ith 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 granu:Lation
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 10%, preferably from 10-95%, more preferably from 20- ;
95~, and most preferably from 40%-95%. ^-
... ~ ,. .
It is preferred that the moisture in the surfactant
aqueous paste is as low as po~sible, while maintaining
paste fluidity, since low moisture leads to a higher
concentration of the surfactant in the finished particle.
Preferably the paste contains bekween 5 and 40~ water, more
preferably between 5 an~ 30% water and most preferably
between 5 and 20% water. A highly attractive mode of
operation for lowering the moisture of the paste pr}or to
enteriny 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
I agglamerator.
, .
¦ It is preferable to use high active surfactant pastes -:
I to minimize the total water level in the system during
mixing, granulating and drying. Lower w ter levels allow
W092/~8603 PCT/~S')2/02880
q
for: (1) a higher active sur~actant 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 hiyher 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 5,000 cps to
10,000,000 cps. Preferably, the viscosity of the paste
entering the system is from about 20,000 to about lOO,Ooo
cps. and more preferably from about 30,000 to about 70,000
cps. The viscosity of the paste of this invention is
measured at a temperature oE 70C.
The paste can be introduced into the mixer at an
initial temperature between its softening point (g~nerally
in the range of 40-60C) and its degradation point
~depending on the chemical nature of the paste, e.g. alkyl
sulphate pastes tend to degrade above 75-85C~. 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
lOO~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 ail 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 i~proves the yield
of particles with the desired size. The use of high ~ -
: .
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WO92/18603 PCT/US92/02880
2 i. ~ 7
.
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 pas~e
through holes (extrusion) small enough to allow the desired
flow rate but that keep the pumping pressure to a maximum
feasi~le in the system, highly advantageous result~ are
achieved.
Hiah Active Surfactant Paste
The activity of the aqueous surfactant paste is at
least 30~ and can go up to about 95%; preferred activities
are : 50-80% and 65-75%. The balance of the paste is
primarily water but can include a processing aid such as a ~-
nonionic surfactant. 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 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 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 ~ec. 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.
. .
WO92/~8603
~ ~ 2 ~ ~ g 1 6 7 PCT/US92/02~80
Water-soluble salts of the higher fatty acids, i~e.,
"s~aps", 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 acid~ 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 potassiunt 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
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 glyrerides of
tallow or coconut oil; and the sodium and potassium alkyl
benzene sulfonates in which the alkyl group contains from
about 9 to about 15 carbon atoms, in straight or branched
chain configuration, e.g., those of the type described in
U.S. Pat. Ncs. 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
~roup 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
WO92/18603 PCT/USg2/02880
2 1 ~ 7 `~ ~
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 ln 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 sul~ates containing from
about 10 to 20 carbon atoms in the alkyl group and from
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 cam be performed as part of the fine
dispersion mixing step.
,'':'
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 sul~ur :
trioxide to produce a sulfonic or sulfurio 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 cos~ of NaOH vs. other
neutralizing agents, but is not required as other agents
such as KOH may be used.
. ,. ' ~
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WO92/18603 PCT/US92/02880
2 ~
1~ .
` Water-soluble nonionic surfactants are also useful a~
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 l:l, more preferably about 0.05:1. Nonionics can
be used up to an equal amount of the primary organic
surfactant. Such nonionic materials inc].ude compounds
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 branchec ehain configuration, with from about 4 to 25
moles of et.~ylene oxide per mole of alkyl phenol.
:, .
Preferred nonionics are the water-soluble condensation
products of aliphatic alcohols containing from 8 to 22
carbon atoms, in either straight chain or branched
configuration, with from 4 to 25 moles of ethylene oxide
per more 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 25 moles of ethylene oxide per mole of alcohol; and
condensation products of propylene glycol with ethylene ~
oxide. :-
. :. .
Semi-polar nonionic surfactants include water-soluble
a~ine oxides containing one alkyl moiety of from about 10
: ~ ' '`'"'.:
.
W O 92/18603 . PC~r/US92/028~0
2~gl~7
~4
to 18 carbon atoms and 2 moieties selected from the group
consisting of alkyl groups and hydroxyalkyl groups
containing from 1 to about ~ 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 1 to 3 carbon atoms; and water~
soluble sulfoxides containing one alkyl moiety of from
about 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
suIfates 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
sul~onates containing from about 14 to 16 carbon atoms;
alkyldimethylamine oxides wherein the alkyl group contains
rom about 11 to 16 carbon atoms; alkyldimethylammonio
propane sulfonates and alkyldimethylammonio hydroxy propane ~-
sulfonates wherein the alkyl group contains from a~out 14
to 18 carbon atoms; soaps of higher fatty acids containing
WO92/1~603 PCT/US92/~2~80
I5
from about 12 to 18 carbon atoms: condensation products of
Cs-clS 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-,
wherein R4 is alkyl having from 10 to 20, preferably from
12-18 carbon atoms, and R5, R6 and R7 are each c1 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.
Spec ~ic preferred surfactants for use herein include:
sodium linear C11-C13 alkylbenzene sulfonate; ~-olefin
sulphonates; triethanolammonium Cl1-C13 alkylbenzene
sulfonate; alkyl sulfates, (tallow, coconut, palm,
synthetic origins, e.g. C45, etc.); sodium alkyl sulfates;
MES; sodium coconut alkyl glyceryl ether sul~onate; the
sodium salt of a sulfated condensa~ion 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 o~ ethylene oxide; 3-(N,N-dimethyl-N-
coconutalkylammonio~-2-hydroxypropane-1-sulfonate; 3-(N,N-
dimethyl-N-coconutalkylammonio)-propane-l-sulfonate; 6- (N-
dodecylbenzyl-N,N-dime~hylammonio) hexanoate;
dodecyldimethylamine oxide; coconutalkyldimethylamine
oxide, and the water-soluble sodium and potassium salts c
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))
: . .
, .
WO92/18603 PCT/US92/02880
2 ~
Ib
to dry detergent builder or powder ranges from 0.005:1 to
19:1, preferably from 0.05:1 to lQ:1, and more preferably
from 0.1:1 to 5:1. Even more preferred said surfactant
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, gèlling,
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 o~ the matrix (caking, compression, etc.).
The Fine DisPersion Mixinq and Granulation
,
~; , .
WO9~/18603 PCT/US92/0288D
21~6 `~
1'1
The term "fine dispersion mixing and/or granulation,"
as used herein, means mixiny and/or granulation of the
mlxture 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-~ 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 i5 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 ~orm 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
the process of the invention inlcude 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 s~l; Italy. ~
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W O 92/18603 ~c~r/US92/02X80
2 1 ~3
18
Other pref~rred suitable equipment can include
EirlchR, series RV, manufactured by Gustau Eirich Hardheim,
Germany; LodigeR, series FM for batch mixing, series Baud
KM for continuous mixiny/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., Bershire, 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.
'
O~eratinq 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 80C,
more preferably between 0 and 70C, even more preferably
between 10 and 60C and most preferably between 20 and
50C. ~ower 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 C02,
and the like; with a preferred method being solid C02, and
the most preferred method beiny nitrogen cooling.
.
A highly attractive opinion ln a preferred embodiment
of the present invention to further increase the
concentration of suxfactant in the final particle, is
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WO9~/18~03
2 ~ 7 PCT/US92/02880
19
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 Aqqlomerate Composition
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 presen* 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 from about 0.5 to about l.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 lO00 microns. The preferred
granules so for~ed have a ~article size range of from 200
to 2000 microns. The more ?re~erred granulation
temperatures range from about 10C to about 60C, and most
preferably from about 20C to about 50~C. ;~
Drying
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W O 92/18603 PC~r/US92/02880
.
2 1 ~ 7
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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 c~mponents 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-B%
free water (i.e. water not associated to any crystalline
species in the agglomerate) and most typically at 2-4%.
DeterqencY 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 o~ the
formula
Na~(A102)z (sio2)y] xH2o
wherein z and y are at least about 6, the molar ratio of z
to y is from about 1.0 to about 0.~ and z is from about 10
to about 26~. Amorphous hydrated aluminosilicate materials
useful herein have the empirical formula
Mz(zAl02 ySiO2)
: :
WO92/1~603 ~ 6 ~ PC~/US92/02880
~i :
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 o~ anhydr~us 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 ahout 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 m2:rix. The crystalline aluminosilicate ion
exchange materials are further characterized by a part:icle
size diameter of from about 0.~ micron to about 10 microns.
Amorphous materials are often smaller, e.g., down to less
than about 0.01 micron. Prefexred ian 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 ~urther 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 aluminosilicate ion exchange materials herein are still
further characte; ~ed 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
WO92/18603 PCT/~S92/02880
,
2 1 ~
hardness. Optimum aluminosilicate for builder purposes
exhibit a calcium ion exchange rate of at least about 4
grains/gallon/~inute/gram/gallon.
The amorphous aluminosilicate ion exchange materials
usually have a Mg+-t 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, incorporated herein by reference.
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
Na12[(A12)12(Si2)12] xH2O
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
solution of seven or greater, and can be either organic or
inorganic in nature. The builder salt assists in providing
th~ 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. ~ ~
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WO92/1~603 PCT/US92/02880
2~ ~9~ L~7
Examples of neutral water-soluble salts include the
alkàli metal, ammonium or substikuted ammonium chlorldes,
fluorides and sulfates. The alkali metal, and especially
sodium, salts of the above are prPferred. 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 t:he rest of the
agglomerate c~mposition.
Other useful water-soluble salts include the compounds
commonly known as detergent builder materlals. Builders
are generally selected from the various water-soluble,
alkali metal, ammonium or substituted ammonium phosphates,
polyphosphates, phosphonat~s, polyphosphonates, carbonates,
silicates, borates, and polyhyroxysulfonates. Preferred
are the alkali metal, especial}y 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 l-hydroxy~l,1-d.tphosphonic acid and the
sodium and potassium salts of ethane, 1,1,2 triphosphonic
acid. Other phosphorus builder compounds are disclosed in
U.S. Pat. Nos. 3,159,581; 3,213,030: 3,422,021; 3,422,137;
3,400,176 and 3,400,148, incorporated herein by reference.
Examples of nonphosphorus, in~_ganic builders are
sodium and potassium carbonate, bicarbonate,
sesquicarbonate, tetraborate decahydrate t 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
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WO92/18603 ~ 1 ~ $ 1 ~ 7 P~T/~S92/028~0
;'~`
invention does not require excess carbonate for processing,
and prefe~ably does not contain over 2% finely divided
calcium carbonate as disclosed in U.S. Pat. No. 4,196,093,
Clarke et al., issued Apr.l, 1980, and is preferably free
of the latter.
As mentioned above powders normally used in detergent~
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 al50 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.
Polymeric polycarboxyate 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.
'.. ~'.
Qptionals
.: .
Other ingredients commonly used in detergent
compositions can be included in the compositions of the
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W092/lX603 PCT/~S92/~28~0
2 ~
present invention. These include fl4w aids, color
speckles, bleaching agents and bleach actlvators, suds
boosters or suds suppressors, antitarnish and anticorrosion
agents, soil suspending agents, soil releaise agents, dyes,
fillers, optical brighteners, germicides, pH adjusting
agents, nonbuilder alkalinity sources, hydrotropPs,
enzymes, en~yme-stabilizing agents, chelating agents and
perfumes.
Optically brighteners may be incorporated either
directly in the agglomerates herein by way of the powder
stream into the agglomerating unit, or in the finished
composition by way of the spray-dried slurry, or via both .
of these routes.
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
suppressSiing activity of these particles is based on fatty
acids or silicones. ~
:
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 Tallow alkyl sulphate. Dobanol 45E7
is a C14/C15 alcohol ethoxylate with 7 U1lits of ethyle.ne
oxide and is manufactured by Shell Co. ~
-:"
The invention will be better understood in view of the
following nonlimiting examples. The percentages are on an
after drying weight basis, unless otherwise specified. The
tables are followed with additional processing disclosure. --
. .
; Example 1
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,~.: :.:.
WO92/1~603 PCT/US~2/~2880
2~8:l~7
An aqueous surfactant LAS paste having a detergent activity
of 78~ and a water content of 21~ is pumpecl ~ia a positive
displacement pump into a Lodige CB 55 at a rate of 20 T/hr.
The viscosity of the paste is 25,000 cps at a temperture of
70~C. At the same time, a powder stream containing a
mixture of l:l ratio by weight of Zeolite A to citrate
dihydrate finely divide, is also fed to the Lodige CB 55
mixer at a rate of 4 T/hr. Also flowing into the sa~e
mixer are two streams containing the recycle of the
classification of the agglomerates, one containing wet
coarse particles and the other dry fine particles. The
agglomerates leaving the Lodige CB 55 mixer are dried in a
controlled temperature fluid bed with air exit temperatures ~ E
of 50~55C. After drying for an averaye residence time of
approximately 15 minutes, the agglomerates are cooled in a
second ~luid bed to powder exit temperatures below 45~C.
The cool dry product leaving the cooler is classified
through mesh ~ieves and the desired particle sizes stored
in a silo. The agglomerates made during this Example have
a detergent activity of 25% and a density of 780 g/L.
Example 2
Example 2 is similar to Example l. In this case, an
aqueous surfactant C4SAS paste with a detergent activity of
70% and a water content of 25% is used at a rate of 2.0
T/hr. The viscosity of the paste is 35,000 cps at a
temperature of 70C. The powder stream consists of a
mixture of a 2:1 ratio by weight of Zeolite A and sodium
carbonate finely divided and is fed at a rate of 2.0 T/hr.
The agglomerates made during this Example have a detergent
activity of 39~ and a density of 675 g/L.
Example 3
This Example describes the process in batch mode in a pilot
plant scale high shear mixer, an Eirich RV02. The mixer is ~
filled first with a mixture of the powders to be used, in `~ -
:
~:"~ "',~ "''
WO92/18603 PCT/US92/02880
this particular case a 2:1 ratio of Zeolite A and finely
divided sodium carbonate (3 kg). An aqueous surfactant MES
paste with a detergent activi-ty of 65% and a water content
of 33% is then added on top of the powder mixture while the
mixer is being operated at 1600 rpm. Enough paste is added
until granulation is achieved (in this ca.,e, 1.6 kg of the
MES paste). The agglomerat~s are discharged onto a fluid
bed drier and then classified through adequate sieves. The
resulting agglomerates are made with a detergent activity
of 22~ and a density of 750 g/L.
,~
Example 4
This Example is similar to Example 3. The powder mixture
is again a 2:1 ratio of Zeolite A to finely divided
carbonate. The surfactant is an aqueous paste of C45AS
with a detergent activity of 78% and a water content o~ i
13%. In this Example, both the powders (1.05 kg) and the
paste (3 kg) are added to the mixer (the Eirich RV02)
before starting the granulation. A certain amount (2 kg)
of dry ice is also added to the mixer to lower the
temperature below -15C. The mixer is then started at a
speed of 1600 rpm. At first, at the low temperature
achieved, the mixture is in the form of a fine powder. The
mixer i5 operated unti the temperature raises to the point
(12~C) where granulation occurs. The process is then
stopped and the agglomerates are dried in a fluid bed and
classified through mesh sieves. The agglomerates made have
a detergent activity of 60% and a density of 625 g/L. They
show excellent physical properties.
Example 5
:. '
i An aqueous surfactant C45AS paste with a detergent activity
~ of 71% and a water content of 28~ is pumped via a positive ^ -
¦ displacement pump into a Lodige CB 30. At the same time, a
powder stream containing a mixture of 2:~ ratio by ~eight
~ of Zeolite A finely divided sodium carbonate, is also fed
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W O 92/18603 PC~r/US92/02880
2 ~ O ~ 1 ~ 7
~V.
to the lodige CB 30. The rate of the powder stream is
maintained constant at 400 Kg/hr. The rate of the paste
stream is varied until agglomerates of an adequate particle
size distribution (a maximum yield between 200 ~m and 1800
~m~ are obtained. Operation at ambient conditions required
a rate of 245 kg/hr. of the surfactant paste being pumped,
resulting in agglomerates (after dxying) of a detergent
activity of 27%. A liquid nitrogen stream is then flown
into the Lodige CB 30 at the point of entrance of the
powder stream, at a rate of 4 . 5 kg/hr. In order to make
agglomerates of an adequate particle size distribution, the
paste flow rate needs to be increased to 346 kg/hr,
resulting in agglomerates (after drying) of a detergent
activity of 32.0%.
Example 6
In this Example, a Braun Multipractic food processor is
used to manufacture agylomerates containing a full
detergent formula for use in laundry cleaning. First, all
the powder components of the formula are weighed and added
to the food processor. This mixture contains :
Zeolite A 160.8 g
Cikrate dihydrate 76.9 g
Sokalan CP5 P/V20.8
Silicate 20R12~7 g
Sodium Carbonate28.8 g
: .
All the powders are in a finely divided form prior to
addition to the mixer. The mixer is then operated at a low
speed for a period o~ about l minute to ensure good mixing
of the powders. A mixture of surfactant pastes is prepar~d
in a separate food processor. This mixture contains :
LAS (78% active, 21% water~ 59.2 g
TAS (55% active, 44% water) 42.0 g
Dobanol 45E7 (100% active) 15.4 g
~Og2/18S03 ~ ~ S~ ~ 7
, . ~4
The pastes are well mixed ~y operating the food proc~or
at high speed for a perlod of about 1 minute. A~ter this,
the powder premix is added on top of the paste pre~ix and
the ~ood processor is oparated at medium speed until
granulation occurs (about 1 mlnute). The ag~lomerateq made
are dried in a fluid ~ed, and classified using mesh sieves.
These agglomerates have excellent physical properties and
very good solubility, showing excellent pearformance in
laundry cleaning.
-:
~'
This example demonstrates that ~or a granular detergent
composition of which one part. consists o~ an a~glomerated
active paste, the spray-dried nil-surfactant co~ponents
have improved solubility and dispensing properties over
typical deterqent products which are commercially available :
granular detergents that are obtained by spray-drying an ~ :
active slurry co~prisin~ an anionic sur~actant .
A nil-surfactant slurry of the co~position as given under A
and C herebelow and a slurry comprising surfac~ant of the
Sv ~
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W092/l8603 ~ 6 7 PCT/VS92~02880
3~ ~
compositions as given under B herehelow were spray-dried
using a pressure nozzle under standard conditions, the
inlet temperature of the drying air being between 250C and
320~C, the outlet temperature of the drying air being
between 80~C and 120C and the pressure of the nozzle being
between 50 and 100 bar. The ingredients of the slurries,
by weight % are :
A B C
Acrylic-maleic copolymer 21.2 7.6 45
Zeolite~A 30.3 41.2 0.0
Diethylene Triamine Penta Methylene
Phosponic acid 2.3 1.1 5.3
Brightener 1.0 0.5 2.2
~nionic surfactant 0.0 9.6 0.0
Moisture and miscellaneous 45.0 40.0 ~7.0
Fig. 1 shows that in the range of shear rates of 1000
to lO.OOO s~l, the nil-surfactant slurry of composition A
of the example has a viscosity that is comparable to the
viscosity of the slurry of composition B, that contains
surfactant and a larger amount of builder.
Spray-drying of compositions having relatively low levels -
of zeolite using known pressure nozzles therefor presents
no problems.
From Figure l, it is seen that for a slurry of composition
C, containing no zeolite and larger amounts of polymer, the
viscosity is higher, so that spray-drying is unpractical.
A minimum amount of bu.ilder is th2refor necessary in the
nil-surfactant slurry for good spray-dryability.
Fig. 2 shows the solubility of the nil-surfactant
spray-dried powder produced from the slurry of composition ~ -
A, compared to the spray~dried active powder produced from
the slurry of composition B. The spray-dried nil- -
surfactant powder has a slightly slower rate of dissolution
and as a result gel formation is reduced and less residues
remain after dispensing. In a comparative test using a
`: .:
W~92/18603 PCT/US92/02~80
2 1
: 31
Zanussi(R) laundry machine, at a water feed rate of 2 lmin~
1 at 20C, con~entional detergents with spray-dried
surfactants showed 30-90~ residue, whereas the granular
dPtergent comprising the nil-surfactant ~pray-dried powder
and the agglomerated surfactant paste ~howed le~s than 5%
residues.
The particle size distribution of the nil-surfactant
spray-dried powder is good fox use in a detergent powder,
the mass remaining on standard sieves being :
No Mesh width l~m~
14 1180 3.1%
22 850 3.7% --
36 ~25 18.8%
250 33.9~
100 150 30.4%, 10.1% falling
through standard sieve no 100.
For spray-dried products it is desirable to have a low
frangibility as this avoids break-up of the finished ~-
detergent powder during storage and handling. -
The frangibility of the nil-surfactant spray-dried powder
was tested by placing the nil-surfactant spray-dried powder
remaining on standard sieves no 22 and 36 in a ball mill
for 5 minutes and determining the percentage falling
through tandard sieve 36 after the ball-mill treatment.
The percentage passing through the sieve 36 after ball-mill
treatment was 66.15% for the nil-active spray-dried powder,
which is comparable with the frangibility of the
conventional powder formed of the slurry of composition B ;
of this example.
' ::.
Granular detergent powders formed by agglomerating a
high active paste using the larger part of the total amount
o builder contained in the detergent powder, and mixing
with nil-surfactant spray~dried powder and other
~ :` ;,': '.
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WO~2/18603 PCT/US92/028~0
2 ~
ingredients, have in many aspects better performance than
when some or all of the surfactant is spray-dried.
_am~le 9
This example demonstrates that a high-density granular
detergent is obta.ined by spray-drying a nil-surfactant
slurry~ subsequently spraying a non-ionic surfactant onto
the nil-surfactant spray-dried slurry and mixing the
resultant powder with the granulated surfactant and dry
additives such as bleach and enzyme.
A nil-surfactant slurry was spray-dried using pressure
nozzles at 50-100 bar pressure, the drying air having a
inlet temperature of ~50C-320C and an outlet temperature
of 80C-120C, the composition of the slurry being by
weight % :
Acrylic-maleic copolymer 9.8%
Zeolite - A 44.7%
Diethylene triamine penta
methylene phosphonic acid 1.7%
Magnesium sulphate 1.8%
Brightener 0.8%
Miscellaneous/water 41.2%
The spray dried powder had a bulk density of 610 g/l.
As a nonionio surfactant an alkyl alcohol ethylene oxide
condensate (AE3) is sprayed onto the spray-dried powder.
Subsequently the resulting powder is mixed with the
agglomerated aninonic surfactant which is produced
according to one of the examples 1 to 7, and further ~:
ingredients such as builder, bleach and enzyme are addedO
The finished detergent composition, having the
following components by weight %, has a density of 800 g/l.
.:
.
WO92/18603 P~T/~592/02880
33 2 ~ 6 7
Spray dried powder ~O%
Nonionic surfactant 6%
Sur~actant powder made by agglomeration 19%
Builder 17
Bleach system 30%
Enzyme 3%
Miscellaneous/water 5
Example lO
. .
This example demonstrates that spray-drying of the nil-
surfactant slurry comprising builder, results in a powder ;
having a relatively high absorption capacity for non-ionic
surfactants compared to the absorption capacity of non- ;
spray dried builder powder. Therefore, more non-ionic
surfactant can be incorporated in less builder powder, so
that more builder powder is available for the agglomeration
of the surfactant paste. This is contrary to the
expectation that more efficient use of builder powders
could be made by spray-drying slurries containing very low
amounts~ or no builder (detergency) powder at all and by
spraying nonionic surfactant onto the resultant powder with
simultaneous dry addition of builder (detergency) powders~
A powder having the following components by weight %
was made by spray-drying :
D E
Acrylic-maleic copolymer 24.3 14.6
Zeolite-A ~3.0 66.3
Diethylene triamine penta
methylene phosphonic acid 4.2 2.5
Magnesium sulphate 4.4 2.7
Brightener 2.0 1.6
Misce~llaneous/water 14.3 12.3
The powders of the composition given under D and E were
sprayed with an alcohol containing 25 carbon atoms
. :
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. ::
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WO92/18603 PCT/US92/028~0
1 ~ 7 3~ ~
ethoxylated with 3 moles of ethylene oxide per mole of
alcohol (C25AE3) as a nonionic surfactant.
Thereafter further zeolite-A was added where necessary
to produce a handable powder. The resulting powder of the
compositions given under D and E containecl the following
ingredients by mass :
D E
Spray-dried powder (kg) 9.0 15.1
Nonionic surfactant (kg) 5.0 5.0
(C25AE3)
Added Zeolite-A (kg) 11.3 0.00
Total 25.3 20.1
Total Zeolite-A to nonionic ratio 3.2 2.90
Total dry powder to nonionic ratio 4.1 3.0
clearly the composition given at E requires less Zeolite-A,
so that the remaining Zeolite-A can be used for
agglomeration of the surfactant paste or for dry~mixing.
