Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
WO 95/28462 ~, ~ j1 ~ ~ ~ ~ 218 7 4 3 9
PCTIUS95104210
1
a
DETERGENT COMPOSITIONS COMPRISING DYE TRANSFER INHIBITORS,
AND PROCESS FOR MAKING THEM
The present invention relates to a free-flowing powder
having a high bulk density comprising certain polymers
useful as dye transfer inhibitors in the cleaning of, for
3
example, laundry items.
The invention also relates to a process for making the
free-flowing powder.
The use of various polymers as dye transfer inhibitors in
detergent compositions has been described in the prior art.
One method of incorporating the polymers into granular
W095/28462 ~ ~ ~ PCTIUS95104210
2
detergent compositions has been to dry mix powdered
polymers with other granular components.
However it has been noted that there is a problem of
lumping and caking of granular detergents associated with
using hygroscopic polymer powders in this way. Furthermore
there are difficulties of bulk handling the those powders.
US5259994 has addressed these problems by mixing polyvinyl
pyrollidone with zeolite, a hydrating salt (e. g. carbonate)
and a binding agent to prepare a free-flowing detergent
additive. However, the small, anhydrous additive readily
absorbs water upon contact. The resulting gel can have an
adverse effect on product dispensing.
US4414130 discloses a "readily disintegrable, insoluble,
detergent builder particulate agglomerate comprising
[aluminosilicate] held together by a water soluble binder."
One such binder which is mentioned is Polyclar ~, a PVP
supplied by GAF. Methods of manufacturing agglomerates
include the use of a fine spray of water to promote
adhesion. Example 2(B) discloses a solution of polyvinyl
pyrollidone and polyvinyl alcohol which is agglomerated
with zeolite. This patent is not, however, concerned with
the problems of formulating and processing dye transfer
inhibiting agents.
~' ~: ~ ~ ~?:;~ 5 21$7 4 3 9
W095/28462 ' ~' PCT/US95/04210
i~ : ;1
3
Although polyvinyl pyrrolidone is useful as a dye transfer
inhibitor, other polymers are being sought which are even
more effective. A more effective polymer is one which can
be used in smaller quantities than polyvinyl pyrollidone to
achieve the same effect, and which is cheaper.
In today's granular detergent market it is particularly
important to find an efficient dye transfer inhibition
polymer (or a mixture of polymers), which can be easily
handled as a high bulk density granule, and which can be
added in small amounts to compact products and which does
not have an adverse effect on product dispensing.
The present invention provides a high density agglomerate
which comprises copolymers of N-vinyl.pyrrolidone and N-
vinylimidazole, typically at levels of 58 to 508 by weight.
The present invention also provides a process in which a
premix of specific hygroscopic dye transfer inhibition
polymer with zeolite (or other powder) is prepared prior to
agglomeration.
CA 02187439 2000-03-14
4
Summary of the Invention
In a first aspect, the present invention provides a free-
flowing powder having a bulk density of at least 600 g/1
comprising:
(a) from 20% to 95% by weight, on anhydrous basis, of a
detergent ingredient selected from the group
consisting of aluminosilicate, citrate, silica,
carbonate, bicarbonate, silicate, sulphate,
phosphate, water-soluble polymer and mixtures
thereof; and
(b) from 5% to 50% by weight of a polymeric dye transfer
inhibitor selected from the group consisting of
polyamine N-oxide polymers, copolymers of N-
vinylpyrrolidone and N-vinylimidazole and mixtures
thereof.
Whilst the free-flowing powder may comprise other components
it is preferred that the level of surfactant is less than 2%
by weight of the powder.
Preferably the free-flowing powder comprises (a) from 50% to
75% by weight (on anhydrous basis) of aluminosilicate and (b)
a mixture of polyamine N-oxide and copolymer of N-
vinylpyrrolidone and N-vinylimidazole, the total polymer level
being from 10% to 30% by weight of the powder.
The mixture of polyamine N-oxide and copolymers of N-
vinylpyrrolidone and N-vinylimidazole is typically in the
weight ratio of from 5:1 to 1:5, and is preferably about 1:1.
CA 02187439 2000-03-14
In a second aspect the present invention provides a process
for making free-flowing particles comprising hygroscopic
powders of polymers comprising the steps of:
(a) mixing a powdered polymer selected from the group
consisting of polyamine N-oxide polymers, copolymers
of N-vinylpyrrolidone and N-vinylimidazole, and
mixtures thereof, with additional powders to form a
powder premix, where the additional powders are
selected from the group consisting of
aluminosilicate, citrate, silica, carbonate,
bicarbonate, silicate, sulphate, phosphate, water-
soluble polymer and mixtures thereof; and
(b) mixing the powder premix with an aqueous solution of
polyamine N-oxide in a high shear mixer to form free-
flowing particles.
A preferred process comprises the steps of (a) mixing from 5%
to 25% by weight of a powdered copolymer of N-vinylpyrrolidone
and N-vinylimidazole with from 50% to 75% by weight (on
anhydrous basis) of sodium aluminosilicate to form a premix,
and (b) mixing the premix with from 5% to 25% by weight (on
active basis) of an aqueous solution of polyamine N-oxide in a
high shear mixer to form free-flowing particles.
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W0 95128462 PCTIUS95104210
B
Optionally, the step of (c) drying the mixture of the
premix. and aqueous solution of binder to form the free-
flowing particles may also be included in the process.
The aluminosilicate, and any other salt present is usually '
fully hydrated prior to the high shear mixer.
Detailed Description of the Invention
All of the percentages herein are by weight of the free-
flowing powder unless otherwise stated.
An essential ingredient of the free-flowing powders of the
present invention is a polymeric dye transfer -inhibiting
agent. Polymeric dye transfer inhibiting agents are
normally incorporated into detergent compositions in order
to inhibit the transfer of dyes from colored fabrics onto
fabrics washed therewith. These polymers have the ability
to complex or adsorb the fugitive dyes washed out of dyed
fabrics before the dyes have the opportunity to become
attached to other articles in the wash.
Especially suitable polymeric- dye transfer -inhibiting
agents are polyamine N-oxide polymers, copolymers of N-
vinylpyrrolidone and N-vinylimidazole, polyvinylpyrrolidone
polymers, polyvinyloxazolidones and polyvinylimidazoles or ,
mixtures thereof.-
CA 02187439 2000-03-14
7
a) Polyamine N-oxide polymers
The polyamine N-oxide polymers suitable for use contain
units having the following structure formula .
P
(I) Ax
R
wherein P is a polymerisable unit. whereto the R-N-O group
can be attached to or wherein the R-N-0 group forms
part of the polymerisable unit or a combination of
both.
0 0 O
A is NC, C0, C, -O-,-S-, -N- ; x is O or 1;
R are aliphatic. ethoxylated aliphatics, aromatic,
heterocyclic or alicyclic groups or any
combination thereof whereto the nitrogen of the N-0
group can be attached or wherein the nitrogen of
the N-O group is part of these groups.
The N-O group can be represented by the following general
structures .
W095128462 ~ , .' PCTlUS95/04210
8
O 0
I
(Rl)x -N- (R2)y =N- (Rl)x
I
(R3) z
wherein Rl, R2, and R3 are aliphatic groups, aromatic,
heterocyclic or alicyclic groups or combinations
thereof, x or/and y or/and z is 0 or 1 and wherein
the nitrogen of the N-O group can be attached or
wherein the nitrogen of the N-0 group forms part of
these groups.
The N-O group can be part of -the polymerisable unit (P)
or can be attached to the polymeric backbone or a
combination of both.
Suitable polyamine N-oxides wherein the N-O group forms
part of the polymerisable unit comprise polyamine N-oxides
wherein R is selected from aliphatic, aromatic, alicyclic
or heterocyclic groups.
One class of said polyamine N-oxides comprises the group of
polyamine N-oxides wherein the nitrogen of the N-0 group
forms part of the R-group. Preferred polyamine N-oxides
are those wherein R is a heterocyclic group such as
pyrridine, pyrrole, imidazole, pyrrolidine, piperidine,
quinoline, acridine and derivatives thereof.
Another class of said polyamine N-oxides comprises the
group
x ~ :.I~~
~~~~c_iyF~3"~
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PC1'IITS95/D4210
9
of polyamine N-oxides wherein the nitrogen of the N-0 group
is attached to the R-group.
Other suitable polyamine N-oxides are the polyamine
oxides whereto the N-O group is attached to the
polymerisable uni t
Preferred class of these polyamine N-oxides are the
polyamine N-oxides having the general formula (I) wherein R
is an aromatic, heterocyclic or alicyclic groups wherein
the nitrogen of the N-0 functional group is part of said R
group.
Examples of these classes are polyamine oxides wherein R
is a heterocyclic compound such as pyrridine, pyrrole,
imidazole and derivatives thereof.
Another preferred class of polyamine N-oxides are the
polyamine oxides having the general formula (I) wherein R
are aromatic, heterocyclic or alicyclic groups wherein the
nitrogen of the N-0 functional group is attached to said R
groups.
Examples of these classes are polyamine oxides wherein R
groups can be aromatic such as phenyl.
Any polymer backbone can be used as long as the amine
oxide polymer formed is water-soluble and has dye transfer
inhibiting properties. Examples of suitable polymeric
backbones are polyvinyls, polyalkylenes, polyesters,
polyethers, polyamide, polyimides, polyacrylates and
mixtures thereof.
WO 95!28462 ~~ ~, j~% ~ ~S ~ ~ ~ ~ ~ ~ PC1'IUS95104210
The .amine N-oxide polymers of the present invention
typically have a ratio of amine to the amine N-oxide of
4
10:1 to 1:1DOOOOD. However the amount of amine oxide groups
present in the polyamine oxide_polymer can be varied by '
appropriate copolymerization or by appropriate degree of N-
oxidation. Preferably, the ratio of amine to amine N-oxide
is from 2:3 to 1:1000000. More preferably from 1:9 to
1:1000000, most preferably from 1:7 to 1:1000000. The
polymers of the present invention actually encompass random
or block copolymers where one monomer type is an amine N-
oxide and the other monomer type is either an amine N-oxide
or not. The amine oxide unit of the polyamine N-oxides has
a PKa < 10, preferably PKa < 7, more preferred PKa < 6.
The polyamine oxides can be obtained in almost any degree
of polymerisation. The degree of polymerisation is not
critical provided the material has the desired water-
solubility and dye-suspending power.
Typically, the average molecular weight is within the range
of 500 to 1000,000; preferably from 1,000 to 50,000, more
preferably from 2,000 to 30,000, most preferably from 3,000
to 20,000.
b) Copolymers of N-vinylpyrrolidone and N-vinylimidazole
The N-vinylimidazole N-vinylpyrrolidone polymers used in
the present invention have an average molecular weight
range from 5,000-1,000,000, preferably from 20,000-200,000.
W O 95/28462 ~ ~ ~~ ~'~ 'r ~ ~ t ~ 2 t t3 7 4 3 9 PCT/US95/04210
11
Highly preferred polymers for use in detergent compositions
according to the present invention comprise a
polymer
selected from N-vinylimidazole N-vinylpyrrolidone
copolymers wherein said polymer has an average molecular
weight range from 5,000 to 50,000 more preferably from
8,000 to 30,000, most preferably from 10,000 to 20,000.
The average molecular weight range was determined
by light
scattering as described in Barth H.G. and Mays J.W.
Chemical Analysis Vol 113,"Modern Methods of Polymer
Characterization".
Highly preferred N-vinylimidazole N-vinylpyrrolidone
copolymers have an average molecula r weight range from
5,000 to 50,000; more preferably from 8,000 to 30,000; most
preferably from 10,000 to 20,000.
The N-vinylimidazole N-vinylpyrrolidone copolymers
characterized by having said average molecular weight range
provide excellent dye transfer inhibiting properties while
not adversely affecting the cleaning performance of
detergent compositions formulated therewith.
The N-vinylimidazole N-vinylpyrrolidone copolymer of the
present invention has a molar ratio of N-vinylimidazole to
N-vinylpyrroiidone from 1 to 0.2, more preferably from 0.8
to 0.3, most preferably from 0.6 to 0.4 .
Y
CA 02187439 2000-03-14
12
c) Polyvinylpyrrolidone
The detergent compositions of the present invention may
also utilize polyvinylpyrrolidone ("PVP" having an average
.molecular weight of from about 2,500 to about 400,000,
preferably from about 5,000 to about 200,000, more
preferably from about 5,000 to about 50,000, and most
preferably from about 5,000 to about 15,000. Suitable
polyvinylpyrrolidones are commercially available from ISP
Corporation, New York, NY and Montreal, Canada under the
product names PVP K-15 (viscosity molecular weight of
10,000), PVP K-30 (average molecular weight of 40,000), pVp
K-60 (average molecular weight of 160,000), and PVP K-90
(average molecular weight of 360,000). PVP K-15 is also
available from ISP Corporation. Other suitable
polyvinylpyrrolidones which are commercially available from
BAS F Cooperation include Sokalan HP 165 and Sokalan HP 12.
Polyvinylpyrrolidones known to persons skilled in the
detergent field: see for example EP-A-262,897 and EP-A
256, 696.
d) Polyvinyloxazolidone .
The detergent compositions of the present invention may
also utilize polyvinylpyrrolidone ("PVP" having an average
molecular weight of from
The detergent compositions of the present invention may
also utilize polyvinyloxazolidone as a polymeric dye
4f.~~,~~~;2187439
WO 95128462 . PCT/US95fO4210
' 13
transfer inhibiting agent. Said polyvinyloxazolidones have
an average molecular weight of from about 2,500 to about
400,000, preferably from about 5,000 to about 200,000, more
preferably from about 5,000 to about 50,000, and most
preferably from about 5,000 to about 15,000.
e) Polyvinylimidazole
The detergent compositions of the present invention may
also utilize polyvinylpyrrolidone ("PVP" having an average
molecular weight of from
The detergent compositions of the present invention may
also utilize polyvinylimidazole as polymeric dye transfer
inhibiting agent. Said polyvinylimidazoles have an average
about 2,500 to about 400,000, preferably from about 5,000
to about 200,000, more preferably from about 5,000 to about
50,000, and most preferably from about 5,000 to about
15,000.
A highly preferred component of the free-flowing powders of
the present invention is aluminosilicate.
Sodium aluminosilicate may take many forms. One example is
crystalline aluminosilicate ion exchange material of the
formula
Naz[(A102)z~(Si02)y]~xH20
~';yi:.~,:~~'~ ~~87439
W0 95/28462 PCTlUS95104210
14
wherein z and y are at least about 6, the molar ratio of z
to y is from about 1.0 to about 0.4 and z is from about 10
to about 264. Amorphous hydrated aluminosilicate materials
useful herein have the empirical formula
Mz(zAlo2-ySi02)
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 CaC03 hardness per
gram of anhydrous aluminosilicate. Hydrated sodium Zeolite
A with a particle size of from about 1 to 10 microns is
preferred.
The aluminosilicate ion exchange builder materials
herein are in hydrated form and contain from about 5~ to
about 28$ of water by weight if crystalline, and
potentially even higher amounts of water i~ amorphous.
Highly preferred crystalline aluminosilicate ion exchange
materials contain from about 15~ to about 22~ water in
their crystal matrix. The crystalline aluminosilicate ion
exchange materials are further characterized by a particle
size diameter of from about 0.1 micron to about 10 microns.
Amorphous materials are often smaller, e.g., down to less
than about 0.01 micron. Preferred ion exchange materials
have a particle size diameter of from about 0.2 micron to
about 4 microns. The term "particle size diameter" herein
represents the average particle size diameter by weight of
a given ion exchange material as determined by conventional
..., ~s~X187439
WO 95/28462 ;~ ~~ ~, ~ ~ ~ ~ PCTIUS95104210
analytical techniques such as, for example, microscopic
determination utilizing a scanning electron microscope.
The crystalline aluminosilicate ion exchange materials
herein are usually further characterized by their calcium
ion exchange capacity, which is at least about 200 mg
equivalent of CaC03 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 characterized by their calcium ion exchange rate
which is at least about 2 grains
Ca++/gallon/minute/gram/gallon of aluminosilicate
(anhydrous basis), and generally lies within the range of
from about 2 grains/gallon/minute/gram/gallon to about 6
grains/gallon/minute/gram/gallon, based on calcium ion
hardness. Optimum aluminosilicate for builder purposes
exhibit a calcium ion exchange rate of at least about 4
grains/gallon/minute/gram/gallon.
The amorphous aluminosilicate ion exchange materials
usually have a Mg++ exchange of at least about 50 mg eq.
CaC03/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
CA 02187439 2000-03-14
16
aluminosilicates useful in this invention can be
crystalline or amorphous in structure and can be naturally
occurring aluminosilicates or synthetically derived. A
method for producing aluminosilicate ion exchange materials
is discussed in U.S. Pat. No. 3,985,669, Krummel et al.,
issued Oct. 12, 1976,
Preferred synthetic crystalline aluminosilicate ion
exchange materials useful herein are available under the
designations Zeolite A, Zeolite 8, Zeolite MAP and Zeolite
X. In an especially preferred embodiment, the crystalline
aluminosilicate ion exchange material has the formula
Nal2[(A102)12(Si02)12]~xH20
wherein x is from about 20 to about 30, especially about 27
and has a particle size generally less than about 5
microns.
The aluminosilicate of the present invention may,
optionally, be fully or partially replaced by other
particulate materials such as citrate, silicate, carbonate,
bicarbonate, sulphate, phosphate, silica and mixtures
thereof.
Water soluble polymers, in addition to the polymeric dye
transfer inhibiting agents,listed above may be incorporated
into the free-flowing powders of the present invention.
Typical examples of such polymers are sodium carboxy-lower
alkyl celluloses, sodium lower alkyl celluloses and sodium
hydroxy-lower alkyl celluloses, such as sodium
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W O 95128462 ~~ t:': ~' ~V ~ ,~~ ~~ ~ PCT/US95104210
17
carboxymethyl cellulose, sodium methyl cellulose and sodium
hydroxypropyl cellulose, polyvinyl alcohols (which often
also include some polyvinyl acetate), polyacrylamides,
r
polyacrylates and various copolymers, such as those of
malefic and acrylic acids. Molecular weights for such
polymers vary widely but most are within the range of 2,000
to 100,000.
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, itaconic acid, mesaconic acid, fumaric acid, aconitic
acid, citraconic acid and methylenemalonic acid.
It is preferred that the free-flowing powders of the
present invention comprise less than 2~ by weight of
surfactants, and preferably do not contain any surfactants.
However, where surfactants are incorporated, anionic,
nonionic, cationic, amphoteric, and zwitterionic
surfactants may be used.
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WO 95128462 ~~ ~ ~ PC1'IUS95I04210
;.
18
Process
The preferred process of the present invention comprising .
the steps of:
(a) mixing a powder comprising copolymers of
N-vinylpyrrolidone and N-vinylimidazole with
additional powders, to form a powder premix; and
(b) mixing the premix with an aqueous binder in a
high shear mixer to form free-flowing particles.
The aqueous binder in step (b) is preferably an aqueous
solution of a polyamine N-oxide polymer, preferably poly(4-
vinyl pyridine N-oxide).
High shear mixers suitable for use in the present invention
include the FukaeR FS-G series manufactured by Fukae
Powtech Kogyo Co., Japan; this apparatus is essentially in
the form of a bowl-shaped vessel-accessible via a top port,
provided near its base with a stirrer having a
substantially vertical axis, and a cutter_positioned on a
side wall. The stirrer and cutter may be operated
independently of one another and at separately variable
speeds. The vessel can be fitted with a cooling jacket or,
if necessary, a cryogenic unit.
Other similar mixers found to be suitable for use in the .
process of the invention include DiosnaR V series ex Dierks
& SShne, Germany; and the Pharma MatrixR ex T K Fielder
~:~~~-.r~#;~.. zt,~~439
W0 95128462 PCT/US95/04210
19
Ltd., England. Other mixers believed to be suitable for
use in the process of the invention are the FujiR VG-C
series ex Fuji Sangyo Co., Japan: and the RotoR ex
Zanchetta & Co srl, Italy.
Other preferred suitable equipment can include EirichR,
series RV, manufactured by Gustau Eirich Hardheim, Germany;
LtidigeR, series FM for batch mixing, series Baud FQ~I for
continuous mixing/agglomeration, manufactured by L<Sdige
Machinenbau GmbH, Paderborn Germany; DraisR T160 series,
manufactured by Drais Werke GmbH, Mannheim Germany; and
WinkworthR RT 25 series, manufactured by Winkworth
Machinery Ltd., Berkshire, England. A. particularly
preferred combination of mixers is a LSdigeR CB mixer,
followed in series by a LbdigeR FQ2 mixer.
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.
WO 95128462 ~ ~ ~~~ ~ ~ ~ ~ ~ ~ ~ PCT/US95104210
After the mixing step, an additional drying step may be
employed. A continuous fluidised bed dryer is suitable for
this.
The particle size of the free-flowing particles of the
present invention may also be important, particularly with
regard to the tendency to form gel upon contact with water
which has an adverse effect upon product dispensing. It is
preferred that small particles, especially "fines" are
avoided. Preferably the mean particle size is greater than
300 micrometers, preferably greater than 450 micrometers,
and most preferably about 550 micrometers. Average particle
size may be conveniently calculated by splitting the
product into a series of fractions on a series of sieves of
decreasing mesh aperture, and measuring the weight of each
fraction.
Finished Product Compositions
It is expected that the free-flowing particles of the
present invention will be added to other granular
components to give a finished product composition. Other
granular components may be prepared by any suitable means
including spray drying, spray cooling, and agglomeration.
Compact detergent compositions (i.e. those having a bulk
density of at least 600 gll) according to the present
invention typically comprise from 0.001 to 10
- + (~ -
2~ X31439
W095I28462 '~ PCTIUS95I04210
21
preferably from 0.018 to 28, more preferably from 0.058 to
18 by weight of a polymeric dye transfer inhibiting agents.
a
Bulk density
All the bulk densities referred to herein are measured by
the non-compacted repour cup density method. This method
uses an apparatus consisting of a funnel mounted above a
500 ml cup, the distance from the base of the funnel to the
top of the cup being 50mm. The cup is filled to overflowing
with product from the funnel (through an aperture of 40mm
diameter). Without tapping the cup, excess product is
removed by scraping away excess by means of a straight edge
across the top of the cup. The net weight of product is
then measured~and recorded, and bulk density is calculated
according to the volume of the cup.
Examples
In the examples the following abbreviations have been used:
PVPVI Copolymers of N-vinylpyrrolidone and
N-vinylimidazole having a molecular weight of
~ 10000.
PVNO Poly (4-vinyl pyridine N-oxide) having a
molecular weight of 10000.
~ # ~ ~'~ 3 9 Pcams9sroazio
wo ssnsasz
zz
Example 1
The following premix was prepared in a batch vertomix
blender:
Zeolite 4A 80 parts by weight
PVPVI 10.5 parts by weight
The premix was transferred on a continuous basis by means
of a feeding screw to the inlet port of a Loedige~ CB high
shear mixer operated at 1700 rpm. An aqueous solution of
PVNO (having an active content of 359) was pumped to spray
nozzles in the mixer. At the same time water was pumped to
additional spray nozzles in the mixer. The components being
added in the following ratio:
Premix 90.5 parts by weight
PVNO Solution 30 parts by weight
Water 8 parts by weight
The wet powder at the exit port of the high shear mixer was
transferred directly into the inlet port of a Loedige~ KM
mixer operating at 140 rpm.
Further agglomeration of the wetpowder took place in the
second mixer to form a wet agglomerate. With the exit gate
of the second mixer fully open, wet agglomerates were .
transferred by a vibrating tube into a continuous fluidised
bed supplied with air at 120°C.
7 wt,» .;
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WO 95128462 '
23
The resulting free-flowing powder had a bulk density of 700
g/1 and a composition of:
Zeolite (anhydrous basis) 65$
PVPVI 10.5$
PAC 10.5$
Water 9$
Miscellaneous * 5$
(*miscellaneous are principally impurities brought into the
process with the zeolite).
Example 2
The process of example 1 was repeated except the premix was
prepared in a continuous ribbon blender, and subsequently
conveyed to the inlet of the Loedige~ CB mixer using a
pneumatic conveying system, and a feeding screw. The
Loedige~ CB mixer was operated at 1000 rpm.
Example 3
The process of example 1 was repeated with a 10 cm weir in
the fluidised bed. The weir had the effect of increasing
the residence time in the fluidised bed to 5 to 10 minutes. t
', ' ~~ ~ ~ ~ ~ ~ ~ ~ PC'TIUS95104210
WO 95/28462
24
Example 4
The premix of example 1 was prepared in a high shear
Eirich~ mixer. The PVNO solution was then added directly to
the Eirich~ mixer resulting in agglomeration of the premix
to form wet granules. The granules were then transferred to
a batch fluidised bed supplied with air at 100°C and dried.
