Note: Descriptions are shown in the official language in which they were submitted.
CA 02263748 1999-02-10
WO 98106816 PCT/US97/12948
PROCESS FOR MAKING HIGH DENSITY DETERGENT
FIELD OF THE INVENTION
The present invention generally relates to a process for producing high
density detergent
compositions. More particularly, the invention is directed to a continuous
process during which
high density detergent agglomerates are produced by feeding a surfactant paste
and dry starting
detergent material into a mixer/densifier having a centrally positioned
rotating shaft with
minimal vibration. The process produces a free flowing, high density detergent
composition
which can be commercially sold as a low dosage or "compact" detergent
composition.
BACKGROUND OF THE INVENTION
Recently, there has been considerable interest within the detergent industry
for laundry
detergents which are "compact" and therefore, have low dosage volumes. To
facilitate
production of these so-called low dosage detergents, many attempts have been
made to produce
high bulk density detergents, for example with a density of 600 g/1 or higher.
The low dosage
detergents are currently in high demand as they conserve resources and can be
sold in small
packages which are more convenient for consumers.
Generally, there are two primary types of processes by which detergent
granules or
powders can be prepared. The first type of process involves spray-drying an
aqueous detergent
slung in a spray-drying tower to produce highly porous detergent granules. In
the second type
of process, the various detergent components are dry mixed after which they
are agglomerated
with a binder such as a nonionic or anionic surfactant. In both processes, the
most important
factors which govern the density of the resulting detergent granules are the
density, porosity and
surface area ofthe various starting materials and their respective chemical
composition. These
parameters, however, can only be varied within a limited range. Thus, a
substantial bulk density
increase can only be achieved by additional processing steps which lead to
densification of the
detergent granules.
There have been many attempts in the art for providing processes which
increase the
density of detergent granules or powders. Particular attention has been given
to densification of
spray-dried granules by post tower treatment. For example, one attempt
involves a batch
process in which spray-dried or granulated detergent powders containing sodium
tripoiyphosphate and sodium sulfate are densified and spheronized in a
Marumerizer~. This
apparatus comprises a substantially horizontal, roughened, rotatable table
positioned within and
at the base of a substantially vertical, smooth walled cylinder. This process,
however, is
essentially a batch process and is therefore less suitable for the large scale
production of
detergent powders. More recently, other attempts have been made to provide a
continuous
CA 02263748 1999-02-10
WO 98/06816 PCT/US97/12948
processes for increasing the density of "post-tower" or spray dried detergent
granules.
Typically, such processes require a first apparatus which pulverizes or grinds
the granules and a
second apparatus which increases the density of the pulverized granules by
agglomeration.
These processes achieve the desired increase in density by treating or
densifying "post tower" or
spray dried granules.
All of the aforementioned processes are directed primarily to densifying or
otherwise
processing spray dried granules. Currently, the relative amounts and types of
materials
subjected to spray drying processes in the production of detergent granules
has been limited.
For example, it has been difficult to attain high levels of surfactant in the
resulting detergent
composition, a feature which facilitates production of low dosage detergents.
Thus, it would be
desirable to have a process by which detergent compositions can be produced
without having
the limitations imposed by conventional spray drying techniques. To that end,
the art is also
replete with disclosures of processes which entail agglomerating detergent
compositions. For
example, attempts have been made to agglomerate detergent builders by mixing
zeolite and/or
layered silicates in a mixer to form free flowing agglomerates.
However, in all of the aforementioned processes, continuous large-scale
production
tends to have its difficulties, especially relative to obtaining acceptable
product consistently and
with minimal wear and tear on the manufacturing equipment. For instance, while
certain
mixer/densif ers work extremely well at the lab scale or even at the pilot
plant scale, their
performance is not always reproducible in large-scale commercial continuous
manufacturing
facilities.
One problem that has arisen involves excessive vibration of the rotating
shafts in
commercial scale mixer/densifiers which can have deleterious effects on the
detergent
composition produced as well as on the mixer/densifiers and other closely
located
manufacturing equipment. This problem can also lead to structural damage to
the
manufacturing building for which substantial expenditures may be required for
repair. Thus,
there remains a need for a means by which commercial scale mixeddensifiers
used to produce
low dosage, high density detergent compositions can be operated continuously
without
significant mechanical vibration and damage resulting therefrom.
Accordingly, there remains a need in the art to have a process for
continuously
producing a high density detergent composition that involves a mixer/densifer
with minimal
mechanical vibration. Also, there remains a need for such a process which is
more efficient and
economical to facilitate large-scale production of low dosage or compact
detergents.
BACKGROUND ART
The following references are directed to densifying spray-dried granules:
Appel et al,
U.S. Patent No. 5,133,924 (Lever); Bortolotti et al, U.S. Patent No. 5,160,657
(Lever); Johnson
CA 02263748 2001-07-23
et al, British Patent No. 1,517,713 (Unilever); and Curtis, European Patent
Application 451,894.
The following references are directed to producing detergents by
agglomeration: Capeci et al, U.S.
Patent 5,366,652; Capeci et al, U.S. Patent 5,486,303; Capeci et al, U.S.
Patent 5,489,392; Capeci
et al, U. S. Patent 5,516,448; Beerse et al, U.S. Patent No. 5,108,646
(Procter & Gamble);
Hollingsworth et al, European Patent Application 351,937 (Unilever); and
Swatling et al, U.S.
Patent No. 5,205,958.
SUMMARY OF THE INVENTION
The present invention meets the aforementioned needs in the art by providing a
process
which continuously produces a high density detergent composition via a process
during which high
density detergent agglomerates are produced by feeding a surfactant paste and
dry starting detergent
material into a mixer/densifier having a centrally positioned rotating shaft
with minimal vibration. In
the process, tuned dampers have been mounted on the centrally rotating shaft
in the mixer/densifier
unexpectedly resulting in a process which produces a high density detergent
composition with
minimal mechanical vibration and repair expenses normally associated such
vibration. The process
produces a free flowing, high density detergent composition which can be
commercially sold as a
low dosage or "compact" detergent composition.
As used herein, the term "agglomerates" refers to particles formed by
agglomerating starting
detergent ingredients which typically have a smaller mean particle size than
the formed
agglomerates. All percentages and ratios used herein are expressed as
percentages by weight
(anhydrous basis) unless otherwise indicated. All viscosities referenced
herein are measured at 70°C
(t5°C) and at shear rates of about 10 to 100 sec ~.
In accordance with one aspect o~f the invention, a process for preparing a
crisp, free flowing,
high density detergent composition is provided. The process comprises the
steps of (a) continuously
mixing a detergent surfactant paste having a viscosity of from about 5,000 cps
to about 100,000 cps
and dry starting detergent material comprising an aluminosilicate builder into
a high speed
mixer/densifier to obtain detergent agglomerates; (b) mixing the detergent
agglomerates in a
moderate speed mixer/densifier to further densify and agglomerate the
detergent agglomerates,
wherein the moderate speed mixer/densilier includes a centrally rotating shaft
on which a tuned
damper apparatus is mounted such that the peak vibration of the shaft is from
about -1.OG to about
1.0G in a frequency range of from about 10 Hz to about 20 Hz at the mid-span
length of the shaft;
and (c) drying the detergent agglomerates so as to form the high density
detergent composition.
In accordance with another aspect of the invention, another continuous process
for
producing a high density detergent composition is provided. The process
comprises the steps of: (a)
continuously mixing spray-dried detergent granules into a moderate speed
CA 02263748 1999-02-10
WO 98/06816 PCT/US97/12948
4
mixer/densifier, wherein the speed mixer/densifier includes a centrally
rotating shaft on which a
tuned damper apparatus is mounted such that the peak vibration of the shaft is
from about -1.OG
to about 1.0G in a frequency range of from about 10 Hz to about 20 Hz at the
mid-span length of
the shaft; and (b) drying the detergent agglomerates so as to form the
detergent composition.
Additionally, the detergent compositions made by any of the processes
described herein is also
provided by the invention.
Accordingly, it is an object of the invention to provide a process for
continuously
producing a high density detergent composition that involves a mixer/densifer
having minimal
mechanical vibration. Also, it is an object of the invention to provide such a
process which is
more efficient and economical to facilitate large-scale production of low
dosage or compact
detergents. These and other objects, features and attendant advantages of the
present invention
will become apparent to those skilled in the art from a reading of the
following detailed
description of the preferred embodiments, drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a flow chart illustrating a preferred process in which two
mixer/densifiers, a
fluid bed dryer, a fluid bed cooler and screening apparatus are serially
positioned in accordance
with a highly preferred embodiment of the invention;
Fig. 2 is a perspective partial cut-away view of a mixer/densifier used in
accordance
with the process which illustrates the tuned damper mounted on the centrally
rotating shaft;
Fig. 3 is a side cross-sectional view of the centrally rotating shaft having a
tuned damper
mounted thereon; and
Fig. 4 is an end view of the rotating shaft in the moderate speed
mixer/densifier
illustrating the tuned damper with four damping apparatus mounted about the
shaft via
connecting bars and clamps.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Process
The present process can be used in the production of low dosage, high density
detergent
compositions containing agglomerates produced directly from starting detergent
ingredients as
well as compositions containing conventional spray-dried granules that have
undergone "post-
tower" densification. By "spray-dried granules", we mean porous granules that
have been made
by drying an aqueous slurry of detergent ingredients including surfactant,
builder and other
standard adjunct detergent ingredients. Typically, the drying is completed by
spraying the
aqueous slurry into a tower having a counter current hot air stream. By "post-
tower"
densification, we mean those detergent granules which have been processed
through a
conventional spray-drying tower or similar apparatus, and thereafter, through
mixer/densifiers
as described herein.
CA 02263748 2001-07-23
Reference is now made to Fig. 1 which presents a flow chart illustrating the
instant
process and various embodiments thereof. In the first step of the process, the
invention entails
continuously mixing into a high speed mixer/densifier 10 several streams of
starting detergent
ingredients including a surfactant paste stream 12 and a dry starting
detergent material stream
14. The surfactant paste 12 preferably comprises from about 25% to about 65%,
preferably
from about 35% to about 55% and, most preferably from about 38% to about 44%,
of a
detergent surfactant in an aqueous paste form. Preferably, the dry starting
detergent material 14
comprises from about 20% to about 50%, preferably from about 25% to about 45%
and, most
preferably from about 30% to about 40% of an aluminosilicate or zeolite
builder, and from
about 10% to about 40%, preferably from about 15% to about 30% and, most
preferably from
about I 5% to about 25% of a sodium carbonate. The surfactant paste 12 and the
dry starting
detergent material 14 are continuously mixed within the ratio ranges described
herein so as to
insure production of the desired free flowing, crisp, high density detergent
composition.
Preferably, the ratio of the surfactant paste 12 to the dry starting detergent
material 14 is from
about 1: IO to about 10:1, more preferably from about 1:4 to about 4:1 and,
most preferably from
about 2:1 to about 2:3.
It should be understood that additional starting detergent ingredients several
of which
are described hereinafter may be mixed into high speed mixer/densifier 10
without departing
from the scope of the invention. It has been found that the first processing
step can be
successfully completed, under the process parameters described herein, in a
high speed
TM
mixer/densifier 10 which preferably is a Lddige CB~mixer or similar brand
mixer. These types
of mixers essentially consist of a horizontal, hollow static cylinder having a
centrally mounted
rotating shaft around which several plough-shaped blades are attached.
Preferably, the shaft
rotates at a speed of from about k 00 rpm to about 2500 rpm, more preferably
from about 300
rpm to about 1600 rpm. Preferably, the mean residence time of the detergent
ingredients in the
high speed mixer/densificr 10 is prefcrably in range from about 2 seconds to
about 45 seconds,
and most preferably from about S seconds to about 15 seconds.
The resulting detergent agglomerates formed in the high speed mixer/densifier
10 are
then fed into a lower or moderato; speed mixer/densifier 16 during which
further build-up
agglomeration is carried forth. In the alternative embodiment, a single stream
of spray-dried
granules~(not shown) is inputted directly into the moderate speed
mixer/densifier, wherein the
high speed mixer/densifier 10 is strictly optional for this particular
embodiment of the invention.
The moderate speed mixer/densifier 16 used in the present process should
include liquid
distribution and agglomeration tools so that both techniques can be carried
forth simultaneously.
It is preferable to have the moderate speed mixer/densifier 16 to be, for
example, a Ltidige KM
(Ploughshare) mixer, Drais~ K-~f 160 mixer or similar brand mixer. The
residence time in the
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WO 98/06816 PCT/ITS97/12948
6
moderate speed mixer/densifier l6 is preferably from about 0.5 minutes to
about 15 minutes,
most preferably the residence time is about 1 to about 10 minutes.
Reference is now made to Fig. 2 in which a perspective partial cut-away view
of
moderate speed mixer/densifier 16 is depicted. As can be seen from Fig. 2, a
centrally located
shaft 18 rotates inside the moderate speed mixer/densifer 16 (e.g. Lodige KM
(ploughshare)
mixer). In accordance with the invention, at least one tuned damper 20 is
mounted on the
rotating shaft 18. Also, the moderate speed mixer/densifer 16 accomplishes
liquid distribution
via cutters 22 mounted on the inside wall of the mixer/densifier 16 and are
generally smaller in
size than the rotating shaft 18. The cutters typically operate at least about
3600 rpm. The
moderate speed mixer/densifer 16 also has ploughs 24 that are mounted to the
centrally rotating
shaft 18 to aid in the mixing/densifying operations in the process and a pair
of inlet ports 21 and
23 that are capable of receiving detergent material from the high speed
mixer/densifier 10.
As alluded to earlier, the rotating shaft 18 has a tendency to experience
relatively
intense mechanical vibration which detrimentally affects the process. In this
regard, it has been
found that by mounting one or more tuned dampers 20 at various points along
the length of the
rotating shaft 18 minimizes or eliminates such undesirable mechanical
vibration. Turning now
collectively to Figs. 3 and 4, wherein Fig. 3 discloses a partial side cross-
sectional view of the
tuned damper 20 and Fig. 4 shows an end view of shaft 18 with the tuned damper
20 mounted
thereon. It can be seen from Figs. 3 and 4 that the tuned damper 20 includes
four cylinder-
shaped damping apparatus 26 to minimize the shaft 18 mechanical vibration. The
tuned damper
20 includes at least two, and preferably four, of these so-called cylinder-
shaped damping
apparatus 26, which are mounted about every 90° on the shaft 18 and
connected via connecting
bars 23. The damping apparatus 26 can be attached to the rotating shaft 18 by
any known
convenient mechanical apparatus such as a split ring assembly that is then
enclosed by a cover
casing 21 as depicted in Figs. 2, 3 and 4. The outer casing 21 of the damping
apparatus of the
tuned damper 20 is preferably made of a material able to withstand the
environment to which it
is exposed. In the current process, the environment is detergent ingredients
which permits the
outer casing 21 to be made from plastic.
The damping apparatus 26 includes a pair of tuning rods 28 and 30 mounted
adjacent to
a pair of flexible or spring-like members 32 and 34. The flexible members 32
and 34 may be
made of any flexible material such as an elastomeric material including
nitrite, natural or
synthetic butyl rubbers (e.g. from Ilene Industries, Inc.) or can be molded to
the final shape by a
supplier (e.g. Forsheda AB, Sweden). The flexible members 32 and 34 contact a
weight 35
which is instrumental in damping the mechanical vibration resulting from the
continuous
rotating speed of the shaft 18.
CA 02263748 2001-07-23
Preferably, the tuned damper 20 is adjusted via manipulation and mounting
location of
the damping apparatus 26 such that the peak vibration of the shaft 18 is
within a selected range,
Specifically, the tuned damper 20 is adjusted via sizing ofthe flexible
members 32 and 34 to
achieve the desired natural frequency of the tuned damper 20. Preferably, the
tuned damper 20
is tuned such that its natural frequency is about 95% of the shaft 18 natural
frequency. If more
than one tuned damper 20 is used, the natural frequency of each tuned damper
20 mounted on
shaft 18 can be distributed at several frequencies in the 10 Hz to 20 Hz
range, or can all be
tuned to the same frequency.
When the tuned damper 20 is properly tuned, the preferred peak vibration range
for the
shaft 18 is from about -I .0G to about 1.0G, more preferably from about -O.SG
to about O.SG,
and most preferably from about -0.256 to about O.ZSG, in a frequency range of
from about 10
Hz to about 20 Hz as measured at the mid-span length of the shaft 18. Such
peak vibration
ranges represent a dramatic improvement over peak vibrations typically
experienced in
commercial scale manufacturing facilities which can be on the order of t3.5G.
The peak
vibration is preferably measured using 90 second intervals. As those skilled
in the art will
appreciate, such peak vibration measurements are easily completed using a
conventional
accelerometer (available from PCB 3088 ICP Company, Buffalo, NY).
For example, during continuous operation of the process, the vibration of
shaft 18 is
recorded using the accelerometer attached to a power supply (e.g., PCB 480E090
from ICP
TM
Company, and a battery operated digital tape recorder such as the Sony TCD-D3
DAT recorder).
The recorder and power supply are mounted in a waterproof, shock proof
enclosure (such as the
TM
Carton C) 1085 Enclosure). The sensor is attached to the shaft 18 by means of
dental cement or
other rigid adhesive and is positioned such that radial shaft vibration is
measured. The vibration
is recorded for at least 2 hours, preferably for 4 hours. Upon completion of
the run, the tape
recorder is removed from the enclosure and played back. The data is plotted in
90 second
TM
intervals on either a digital or analog plotting device (such as the Hewlett-
Packard 3560A or
35b70A analyzers). The peak and rms values of the vibration can be determined
from a PC-
TM TM
based software program such as Excel or Matlab.
While not intending to be bound by theory, the negative peak vibrations
associated with
the moderate speed mixer/densifer 16 are especially exacerbated when the so-
called "detergent
wall" is present on the inner surface of the mixerldensifier 16. During the
process, an optional
detergent coating or wall of at least about a 1 mm can cover a portion of the
inner wall surface
of the moderate speed mixer/densifer 16. The portion of the inner wall covered
by this coating
having a minimum thickness of 1 mm can be substantial (up to 100% of the inner
surface
covered) or a mere 50% can be covered. The presence of this detergent coating
provides an
irregular surface contour against which the ploughs 24 are contacted during
rotation of the shaft
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WO 98/06816 PCT/US97/12948
18 of the moderate speed mixer/densifier 16. This irregular surface results in
the shaft 18 being
subjected to irregular forces, thereby further enhancing the overall
mechanical vibration. The
tuned damper 20, however, eliminates or minimizes this additional mechanical
vibration, as
well.
Referring collectively to Figs. 1-4, the preferred density of the resulting
detergent
agglomerates, or spray-dried granules of the alternative embodiment, exiting
the moderate speed
mixer/densifier 16 is at least 650 g/1, more preferably from about 700 g/1 to
about 800 g/1. The
particle porosity of the resulting detergent agglomerates of the composition
is preferably in a
range from about 5% to about 20%, more preferably at about 10%. While the
detergent
agglomerates or spray-dried granules exiting the moderate speed mixer/densifer
16 are ready for
packaging and sale as a low dosage, compact detergent product at this point,
they can be
subjected to one or more optional processing steps.
Optional Process Stens
Optionally, the detergent agglomerates may be dried in a fluid bed dryer 36 or
similar
apparatus. In another optional step of the present process, the detergent
agglomerates exiting
the fluid bed dryer 36 are further conditioned by cooling the agglomerates in
a fluid bed cooler
38 or similar apparatus as are well known in the art.
Another optional process step involves adding a coating agent to improve
flowability
and/or minimize over agglomeration of the detergent composition in one or more
of the
following locations of the instant process: ( 1 ) the coating agent can be
added directly after the
fluid bed cooler 38 as shown by coating agent stream 40 (preferred); (2) the
coating agent may
be added between the fluid bed dryer 36 and the fluid bed cooler 38 as shown
by coating agent
stream 42; (3) the coating agent may be added between the fluid bed dryer 36
and the moderate
speed mixer/densifier 16 as shown by stream 44; and/or (4) the coating agent
may be added
directly to the moderate speed mixer/densifier 16 and the fluid bed dryer 36
as shown by stream
46. It should be understood that the coating agent can be added in any one or
a combination of
streams 40, 42, 44, and 46 as shown in Fig. 1. The coating agent stream 40 is
the most preferred
in the instant process.
The coating agent is preferably selected from the group consisting of
aluminosilicates,
silicates, carbonates and mixtures thereof. The coating agent not only
enhances the free
flowability of the resulting detergent composition which is desirable by
consumers in that it
permits easy scooping of detergent during use, but also serves to control
agglomeration by
preventing or minimizing over agglomeration, especially when added directly to
the moderate
speed mixer/densifier 16. As those skilled in the art are well aware, over
agglomeration can
lead to very undesirable flow properties and aesthetics of the final detergent
product.
_______~_____.._ _ __~_ _._._. . . _.._ _ _ . _
CA 02263748 2001-07-23
Optionally, the process can comprises the step of spraying an additional
binder in one or
both of the mixerldensifiers 10 and 16. A binder is added for purposes of
enhancing
agglomeration by providing a "binding" or "sticking" agent for the detergent
components. The
binder is preferably selected from the group consisting of water, anionic
surfactants, nonionic
surfactants, polyethylene glycol, polyvinyl pyrrolidone poiyacrylates, citric
acid and mixtures
thereof. Other suitable binder materials including those listed herein are
described in Beerse et
al, U.S. Patent No. 5,108,646 (Procter & Gamble Co.).
Other optional steps contemplated by the present process include screening the
oversized detergent agglomerates or spray-dried granules in a screening
apparatus 48 which can
take a variety of forms including but not limited to conventional screens
chosen for the desired
particle size of the finished detergent product. Other optional steps include
conditioning of the
detergent agglomerates by subjecting the agglomerates to additional drying.
Another optional step of the instant process entails finishing the resulting
detergent
agglomerates by a variety of processes including spraying andlor admixing
other conventional
detergent ingredients, collectively referenced as the finishing step 50 in
Fig. I . For example, the
finishing step encompasses spraying perfumes, brighteners and enzymes onto the
finished
agglomerates to provide a more complete detergent composition. Such techniques
and
ingredients are well known in the art.
Detereent Surfactant Paste
The detergent surfactant paste used in the process is preferably in the form
of an
aqueous viscous paste, although forms are also contemplated by the invention.
This so-called
viscous surfactant paste has a viscosity of from about 5,000 cps to about
100,000 cps, more
preferably from about 10,000 cps to about 80,000 cps, and contains at least
about 10% water,
more preferably at least about 20% water. The viscosity is measured at
70°C and at shear rates
of about 10 to 100 sec.' l . Furthermore, the surfactant paste, if used,
preferably comprises a
detersive surfactant in the amounts specified previously and the balance water
and other
conventional detergent ingredients.
The surfactant itself, in the viscous surfactant paste, is preferably selected
from anionic,
nonionic, zwitterionic, ampholytic and cationic classes and compatible
mixtures thereof.
Detergent surfactants useful herein are described in U.S. Patent 3,664,961,
Norris, issued May
23, 1972, and in U.S. Patent 3,919,6?8, Laughlin et al., issued December 30,
1975.
Useful cationic surfactants also include those described in U.S. Patent
4,222,905, Cockrell,
issued September 16, 1980, and in U.S. Patent 4,239,659, Murphy, issued
December 16, 1980.
CA 02263748 2001-07-23
1~
Of the surfactants, anionics and nonionics are preferred and anionics are most
preferred.
Nonlimiting examples of the preferred anionic surfactants useful in the
surfactant paste
include the conventional C 11-C 1 g alkyl benzene sulfonates ("LAS"), primary,
branched-chain
and random C I0-C20 alkyl sulfates ("AS"), the C 10-C 1 g secondary (2,3)
alkyl sulfates of the
formula CH3(CH2)x(CHOS03 M+') CH3 and CH3 (CH2~,(CHOS03 M+) CH2CH3 where x
and (y + I ) are integers of at least shout 7, preferably at least about 9,
and M is a
water-soiubilizing cation, especially sodium, unsaturated sulfates such as
oleyl sulfate, and the
C 10-C I g alkyl alkoxy sulfates ("AExS"; especially EO I-7 ethoxy sulfates).
Optionally, other exemplary surfactants useful in the paste of the invention
include and
C 10-C 1 g alkyl alkoxy carboxylates (especially the EO I-5
ethoxycarboxylates), the C l0-I8
glycerol ethers, the C I0-C I g alkyl polyglycosides and their corresponding
sulfated
polyglycosides, and C 12-C 1 g alpha-sulfonated fatty acid esters. If desired,
the conventional
nonionic and amphoteric surfactants such as the C 12-C I g alkyl ethoxylates
{"AE") including the
so-called narrow peaked alkyl ethoxylates and C6-C 12 alkyl phenol alkoxylates
(especially
ethoxylates and mixed ethoxy/propoxy), C 12-C 1 g betaines and sulfobetaines
("sultaines"),
C 10-C 1 g amine oxides, and the like, can also be included in the overall
compositions. The CIO-
Clg N-alkyl polyhydroxy fatty acid amides can also be used. Typical examples
include the
C I 2-C 1 g N-methylglucamides. See WO 92/06154. Other sugar-derived
surfactants include the
N-alkoxy polyhydroxy fatty acid amides, such as C I0-C 1 g N-(3-methoxypropyl)
glucamide.
The N-propyl through N-hexyl C 12-C: I g glucamides can be used for low
sudsing. C 10-C20
conventional soaps may also be used. If high sudsing is desired, the branched-
chain C l0-C 16
soaps may be used. Mixtures of anionic and nonionic surfactants are especially
useful. Other
conventional useful surfactants are listed in standard texts.
Drv Detergent Material
The starting dry detergent material of the present process preferably
comprises a detergent
aiuminosilicate builder which are referenced as aluminosilicate ion exchange
materials and sodium
carbonate. The aluminosificate ion exchange materials used herein as a
detergent builder
preferably have both a high calcium ion exchange capacity and a high exchange
rate. Without
intending to be limited by theory, it is believed that such high calcium ion
exchange rate and
capacity are a function of several interrelated factors which derive from the
method by which the
aluminosilicate ion exchange material is produced. In that regard, the
aluminosilicate ion exchange
materials used herein are preferably produced in accordance with Corkil) et
al, U.S. Patent No.
4,605,509 (Procter & Gamble).
Preferably, the aluminosilicate ion exchange material is in "sodium" form
since the
potassium and hydrogen forms of the instant aluminosilicate do not exhibit the
as high of an
CA 02263748 2001-07-23
exchange rate and capacity as provided by the sodium form. Additionally, the
aluminosiiicate ion
exchange material preferably is in over dried form so as to facilitate
production of crisp detergent
agglomerates as described herein. 'The aluminosilicate ion exchange materials
used herein
preferably have particle size diameters which optimize their effectiveness as
detergent builders.
The term "particle size diameter" as used herein represents the average
particle size diameter of a
given aluminosilicate ion exchange material as determined by conventional
analytical techniques,
such as microscopic determination and scanning electron microscope (SEM). The
preferred
particle size diameter of the aluminosilicate is from about 0.1 micron to
about 10 microns, more
preferably from about 0.5 microns to about 9 microns. Most preferably, the
particle size diameter
is from about 1 microns to about & microns.
Preferably, the aluminosilicate ion exchange material has the formula
Naz[(A102)z.(Si02)y)xH20
wherein z and y are integers of at 'least 6, the molar ratio of z to y is from
about 1 to about S and x is
from about 10 to about 264. More preferably, the aluminosilicate has the
formula
1Va12L(A102)12~(Si02)12)~20
wherein x is from about 20 to about 30, preferably about 27. These preferred
aluminosilicates are
available commercially, for example under designations Zeolite A, Zeolite B
and Zeolite X.
Alternatively, naturally-occurring or synthetically derived aluminosilicate
ion exchange materials
suitable for use herein can be made as described in Krummel et al, U.S. Patent
No. 3,985,669.
The aluminosilicates used herein are further characterized by their ion
exchange capacity
which is at least about 200 mg equivalent of CaC03 hardness/gram, calculated
on an anhydrous
basis, and which is preferably in a range from about 300 to 352 mg equivalent
of CaC03
hardnesslgram. Additionally, the instant aluminosilicate ion exchange
materials are still further
characterized by their calcium ion exchange rate which is at least about 2
grains
Ca'+"~/gallon/minute/-gram/gallon, and more preferably in a range from about 2
grains
Ca'i°'~/gallon/minute/-gram/gallon to about 6 grains
Ca'~/gallon/minute/-gram/gallon .
Adjunct Deter eg nt Ingredients
The starting dry detergent material in the present process can include
additional detergent
ingredients andlor, any number of additional ingredients can be incorporated
in the detergent
composition during subsequent steps of the present process. These adjunct
ingredients include
other detergency builders, bleaches, bleach activators, suds boosters or suds
suppressers,
anti-tarnish and anticorrosion agents, soil suspending agents, soil release
agents, germicides, pH
adjusting agents, non-builder alkalinity sources, chelating agents, smectite
clays, enzymes,
enzyme-stabilizing agents and perfumes. See U.S. Patent 3,936,537, issued
February 3, 1976 to
Baskerville, Jr. et al.
CA 02263748 2001-07-23
17
Other builders can be generally selected from the various water-soluble,
alkali metal,
ammonium or substituted ammonium phosphates, polyphosphates, phosphonates,
polyphosphonates, carbonates, borates, polyhydroxy sulfonates, polyacetates,
carboxylates, and
polycarboxylates. Preferred are the alkali metal, especially sodium, salts of
the above.
Preferred for use herein are the phosphates, carbonates, C 10_ 1 g fatty
acids, polycarboxylates,
and mixtures thereof. More preferred are sodium tripolyphosphate, tetrasodium
pyrophosphate,
citrate, tartrate mono- and di-succinates, and mixtures thereof (see below).
In comparison with amorphous sodium silicates, crystalline layered sodium
silicates
exhibit a clearly increased calcium and magnesium ion exchange capacity. (n
addition, the layered
sodium silicates prefer magnesium ions over calcium ions, a feature necessary
to insure that
substantially all of the "hardness" is removed from the wash water. These
crystalline layered
sodium silicates, however, are generally more expensive than amorphous
silicates as well as other
builders. Accordingly, in order to provide an economically feasible laundry
detergent, the
proportion of crystalline layered sodium silicates used must be determined
judiciously.
The crystalline layered sodium silicates suitable for use herein preferably
have the formula
NaMSix02x+1.yH20
wherein M is sodium or hydrogen, x is from about 1.9 to about 4 and y is from
about 0 to about 20.
More preferably, the crystalline layered sodium silicate has the formula
NaMSi205.yH20
wherein M is sodium or hydrogen, and y is from about 0 to about 20. These and
other crystalline
layered sodium silicates are discussed in Corkill et al, U.S. Patent No.
4,605,509. _
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 orthophosphates. 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
U.S. Patents
3,159,581; 3,213,030; 3,422,021; 3,422,137; 3,400,1?6 and 3,400,148.
Examples of nonphosphorus, inorganic builders are tetraborate decahydrate and
silicates
having a weight ratio of Si02 to alkali metal oxide of from about 0.5 to about
4.0, preferably
from about 1.0 to about 2.4. Water-soluble, nonphosphorus organic builders
useful herein
include the various alkali metal, ammonium and substituted ammonium
polyacetates,
carboxylates, polycarboxylates and poiyhydroxy sulfonates. Examples of
polyacetate and
polycarboxylate builders are the sodium, potassium, lithium, ammonium and
substituted
CA 02263748 2001-07-23
13
ammonium salts of ethylene diamine tetraacetic acid, nitrilotriacetic acid,
oxydisuccinic acid,
mellitic acid, benzene polycarboxylic acids, and citric acid.
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 malefic acid, itac;onic acid, mesaconic acid, fumaric
acid, aconitic acid,
citraconic acid and methylene malonic acid. Some of these materials are useful
as the water-soluble
anionic polymer as hereinafter described, but only if in intimate admixture
with the non-soap
anionic surfactant.
Other suitable polycarboxylates for use herein are the polyacetal carboxylates
described in
U.S. Patent 4,144,226, issued March 13, 1979 to Crutchfield et al, and U.S.
Patent 4,246,495, issued
March 27, 1979 to Crutchfield et al. These polyacetal carboxylates can be
prepared by bringing
together under polymerization conditions an ester of glyoxylic acid and a
polymerization initiator.
The resulting polyacetal carboxylate ester is then attached to chemically
stable end groups to
stabilize the polyacetal carboxylate against rapid depolymerization in
alkaline solution, converted to
the corresponding salt, and added to a detergent composition. Particularly
preferred polycarboxylate
builders are the ether carboxylate builder compositions comprising a
combination of tartrate
monosuccinate and tartrate disuccinate described in U.S. Patent 4,663,071,
Bush et al., issued
May 5, 1987.
Bleaching agents and activators are described in U.S. Patent 4,412,934, Chung
et al., issued
November 1, 1983, and in U.S. Patent 4,483,781, Hartman, issued November 20,
1984. Chelating
agents are also described in U.S. Patent 4,663,071, Bush et al., from Column
17, line 54 through
Column 18, line 68. Suds modifiers are also optional ingredients and are
described in U.S. Patents
3,933,672, issued January 20, 1976 to Bartoletta et al., and 4,136,045, issued
January 23, 1979 to
Gault et al.
Suitable smectite clays for use herein are described in U.S. Patent 4,762,645,
Tucker et al,
issued August 9, 1988, Column 6, line :3 through Column 7, line 24. Suitable
additional detergency
builders for use herein are enumerated in the Baskerville patent, Column 13,
line 54 through
Column 16, line 16, and in U.S. Patent 4,663,071, Bush et al, issued May 5,
1987.
In order to make the present invention more readily understood, reference is
made to the
following examples, which are intended to be illustrative only and not
intended to be limiting in
scope.
EXAMPLE I
CA 02263748 1999-02-10
WO 98/06816 PCT/US97/12948
14
This Example illustrates the process of the invention which produces free
flowing, crisp,
high density detergent composition. Two feed streams of various detergent
starting ingredients
are continuously fed, at a rate of 2800 kg/hr, into a Lodige CB-30
mixer/densifier, one of which
comprises a surfactant paste containing surfactant and water and the other
stream containing
starting dry detergent material containing aluminosilicate and sodium
carbonate. The rotational
speed of the shaft in the Lodige CB-30 mixer/densifier is about 1400 rpm and
the mean
residence time is about 10 seconds. The contents from the Lodige CB-30
mixer/densifer are
continuously fed into a Lodige KM 600 mixer/densifer for further agglomeration
during which
the mean residence time is about 6 minutes. The Lodige KM 600 mixer/densifier
includes four
tune dampers connected by a central ring. The tuned dampers are located midway
down the
length of the mixer and are placed around the shaft in 90° intervals.
Each mass o~ weight
element weighs 30 lbs. and the flexible elements in the tuned dampers are
sized and tuned to
about 25 Hz. A(1 four tune dampers are then enclosed in a single cover casing.
The resulting
detergent agglomerates are then fed to a fluid bed dryer and then to a fluid
bed cooler, the mean
residence time being about 10 minutes and 15 minutes, respectively. A coating
agent,
aluminosilicate, is fed about midway down the moderate speed mixer/densifier
16 to control and
prevent over agglomeration. The detergent agglomerates are then screened with
conventional
screening apparatus resulting in a uniform particle size distribution. The
composition of the
detergent agglomerates exiting the fluid bed cooler is set forth in Table I
below:
TABLE I
Comooneot % Weight of Total Feed
C14-15 alkyt sulfate/alkyl ethoxy sulfate 29.1
Aluminosilicate 34.4
Sodium carbonate 17,5
Polyethylene glycol (MW 4000) 1.3
Misc. (water, etc.) 16.7
100.0
Additional detergent ingredients including perfumes, enzymes, and other minors
are
sprayed onto the agglomerates described above in the finishing step to result
in a finished
detergent composition. The relative proportions of the overall finished
detergent composition
produced by the process of instant process is presented in Table II below:
CA 02263748 1999-02-10
WO 98/06816 PCT/US97/12948
TABLE II
(% weight)
Component A
C14-15 alkyl sulfate/C14-15 alkyl ethoxy sulfate 16.3
Neodol 23-6.51 3.0
C12-14 N-methyl glucamide 0.9
Polyacrylate (MW=4500) 3.0
Polyethylene glycol (MW=4000) 1.2
Sodium Sulfate 8.9
Aluminosilicate 26.3
Sodium carbonate 27.2
Protease enzyme 0.4
Amylase enzyme 0.1
Lipase enzyme 0.2
Cellulase enzyme 0.1
Minors (water, perfume, etc.) 12.4
100.0
1 C12-13 alkyl ethoxylate (E0=6.5) commercially
available from Shell Oil Co
mpany.
The density of the resulting detergent composition
is 796 g/I
the mean particle size is
,
613 microns.
EXAMPLE II
This Example illustrates another process in accordance with the invention in
which
granules are first spray dried then mixed in a moderate speed mixer/densifier.
The composition
of the detergent in Table III below is made in a 10 foot diameter spray drying
tower with
counter current air at 300°C at a rate of 2800 lb/hr. The granules are
fed into a Lodige ICM-600
with a residence time of about 12 minutes. The Lodige KM 600 includes four
tune dampers
connected by a central ring. The tuned dampers are located midway down the
length of the
mixer and are placed around the shaft in 90° intervals. Each mass or
weight element weighs 30
lbs. and the flexible elements are sized and tuned to about 25. Hz. All four
tune dampers are
then enclosed in a single cover casing.
TABLE III
Component % Weight of Total
Feed
C14-15 alkyl sulfate/alkyl I0.2
ethoxy sulfate
C 12-13 linear alkylbenzene 10.2
sulfonate
Aluminosilicate 27.0
Sodium carbonate 21.9
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f6
Polyethylene glycol (MW 4000) 1.4
Polyacrylate (MW=4500) 4.0
Sodium Sulfate 13.0
Brightener 0.3
Sodium Silicate ( 1.6r) I .0
Misc. (water, perfume, etc.)
100.0
Additional detergent ingredients including perfumes and enzymes are sprayed
onto the
granules described above in the finishing step to result in a finished
detergent composition. The
relative proportions of the overall fiatished detergent composition produced
by the process of
instant process is presented in Table 1V below:
TABLE IV
(% weie6t)
Component
C 12-16 linear alkylbenzene sulfonate9.0
C14-I5 aMkYl sulfate/C14-15 alkyl 9.0
ethoxy sulfate
Neodol 23-6.51 2.0
Polyacrylate (MW=4500) 3.5
Polyethylene glycol (MW=4000) 1.2
Sodium Sulfate 11.4
Sodium Silicate ( 1.6r) 0.9
Aluminosilicate 23.8
Brightener 0.3
Sodium carbonate 28.4
Protease enzyme 0.4
Amylase enzyme 0.I
Lipase enzyme 0.2
Cellulase enzyme ' 0.1
Minors (water, perfume, etc.)
100.0
1 C12-13 alkyl ethoxylate (EO=6.~) commercially available from Shell Oil
Company.
The density of the resulting detergent composition is 822 g/1.
Having thus described the invention in detail, it will be clear to those
skilled in the art
that various changes may be made without departing from the scope of the
invention and the
invention is not to be considered limited to what is described in the
specification.
