Note: Descriptions are shown in the official language in which they were submitted.
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PF~OCESS FOR FORMlr~G FLAKES
Jack Y~. Revis
John A. Sagel
Daniel 1. Ostendorf
Technical Field and Background Art
The present invention relates to forming flakes of
hydrophilic solid organic material, preferably ~ith other material
10 encapsulated therein, by cooling a melt of said solid organic mate-
rial on a belt cooler. Typical of the desired flaked materials are
those described in U.S. Patent 4,652,392, Baginski et al.
Summary of The Invention
.
The invention comprises a process for forming solid flakes
comprising cooling a thin typically from about 0. 005 to about
0.4, preferably from about 0.01 to about 0.1, most preferably
from about 0.025 to about 0.05, film of a molten water-soluble
or water-dispersible, non-hygroscopic plastic organic material
20 which is preferably impermeable to detergents and /or alkalinity
and most preferably nonsurface active, on a belt cooler, the
surface of said belt cooler being wetted, or at least moistened,
with an effective amount of a hydrophilic solvent, preferably
selected from the group consisting of water and low molecular
2S weight hydrophillc solvents such as C1 4 alcohols containing from
one to about 3 hydroxy groups, so as to improve the rate of
cooling and solidification of said organic material. The surface of
the belt cooler is wetted by dripping, spraying, or wiping a thin
film, typically just enough to moisten the beit surface, of the
30 hydrophilic solvent on the belt immediately prior to the addition
of the plastic organic material.
The molten material, and the resulting flake can, and
preferably do, also comprise other materials that are desirable
and that need protection from their environment. Detergent
35 additives such as the suds controlling components of U. S. Patent
4,652,392; enzymes; cationic softeners; dyes; brighteners;
I ~Ik
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bleachirlg agents; and reducing agents are desirable other
materials, especially said suds controlling components. They are
incorporated at a level of from a trace to about 4096, preferably
from about 0.00196 to about 20%, most preferably from about 0.01%
5 to about 15~.
Detailed Description of the Invention
The molten materials which are formed into solid flakes are
either water-soluble or water dispersible and are non-hygroscopic
in their solid form. Such materials are desirable for use in
10 detergent compositions that are designed to be added to wash
liquors and typically are used to protect other sensitive ingredi-
ents although they can also have utility by themselves. When
they are used to protect silicone suds controlling components such
as in U.S. Patent 4,652,392, it is highly desirable that they be
15 relatively non-surface active and impermeable to detergents and
alkalinity .
By substantially nonsurface active is meant that the carrier
material, itself, does not interact with the silicone material in
such fashion that the silicone material is emulsified or otherwise
20 excessively dispersed prior to its release in the wash water.
I.e., the particle size of the silicone droplet should be maintained
above about 1, more preferably above about 5 microns, and less
than about 100 microns, preferably less than about 50 microns.
Of course, when preparing a dry powder or granulated
25 detergent compositlon, it is preferable that the silicone suds
controlllng component thereof also be substantially dry and
nontacl<y at ambient temperatures. Accordingly, it is preferred
herein to use plastic, organic materials which can be conveniently
melted, admixed with the silicone suds controlling agent, and
30 thereafter cooled to form solid flakes. There are a wide variety
of such plastic materials (carriers) useful herein. Since the
silicone suds controlling agent is to be releasably incorporated in
the carrier, such that the silicone is released into the aqueous
bath upon admixture of the composition therewith, it is preferred
35 that the carrier material be water soluble. However,
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water-dispersible materials are also useful, inasmuch as they will
also release the silicone upon addition to an aqueous bath.
A wide variety of carrier materials having the requisite
solubility/dispersibility characteristics and the essential features
5 of being substantially non-surface active, substantially
nGn-hygroscopic and substantially detergent-impermeable are
known. However, polyethylene glycol (PEG) which has sub-
stantially no surface active characteristics is highly preferred
herein. PEG, having molecular weights of from about 1,500 to
about 100,000, preferably from about 3,000 to about 20,000, more
preferably from about 5,000 to about 10,000 can be used. The
PEG should be solid under all reasonable conditions, e.g., up to
at least about 90F. (32C.), preferably at least 100F. (38C. ),
more preferably at least 110F. (43C. ) .
Surprisingly, highly ethoxylated fatty alcohols such as tallow
alcohol condensed with at least about 25 molar proportions of
ethylene oxide are also useful herein. Other alcohol condensates
containing extremely high ethoxylate proportions (about 25 and
above) are also useful herein. Such high ethoxylates apparently
lack sufficient surface active characteristics to interact or other-
wise interfere with the deslred suds control properties of the
silicone agents herein. A variety of other materials useful as
the carrier agents herein can also be used, e.g., gelatin; agar;
gum arabic; and various algae-derived gels.
A very preferred carrier material is a mixture of from about
0.296 to about 15%, preferably from about 0.2596 to about 5%, more
preferably from about 0 . 25% to about 2% of fatty acids containing
from about 12 to about 30, preferably from about 14 to about 20,
more preferably from about 14 to about 16, carbon atoms and the
balance PEG. Such a carrier material gives a more desirable suds
pattern over the duration of the washing process, providing more
suds at the start and less suds at the end than PEG alone. The
fatty acid delays the solubility of the suds suppressor particle
and thereby delays the release of the silicone.
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The preferred flaked particulate silicone suds controllin~
component of the present invention can be conveniently prepared
by cooling molten carrier material with the suds suppressor
dispersed therein on a belt cooler and then breaking said Film
into appropriate sized flakes.
The preferred suds controlling component of the instant
composition comprises a silicone suds controliing agent which is
incorporated in a water-soluble or water-dispersible, substantially
nonsurface active, detergent-impermeable and, non-hygroscopic
carrier material. The carrier material contains within its interior
substantially all of the silicone suds controlling agent and effec-
tively isolates it from (i.e., keeps it out of contact with) the
detergent component of the compositions. The carrier material is
selected such that, upon admixture with water, the carrier matrix
dissolves or disperses to release the silicone material to perform
its suds controlling function.
The silicone materials employed as the suds controlling
agents herein can be alkylated polysiloxane materials of several
types, either singly or in combination with various solid materials
such as silica aerogels and xerogels and hydrophobic silicas of
various types. In industrial practice, the term "silicone" has
become a generic term which encompasses a variety of relatively
high molecular weight polymers containing siloxane units and
hydrocarbyl groups of various types. In general terms, the
silicone suds controllers can be described as siloxanes having the
general structural backbone.
sio
R'
wherein x is from about 20 to about 2,000, and R and R' are each
alkyl or aryl groups, especially methyl, ethyl, propyl, butyl or
phenyl. The polydimethylsiloxanes (R and R' are methyl) having
a rr olecular weight within the range of from about 200 to about
200,000, and higher, are all useful as suds controlling agents.
Silicone materials are commercialiy available from the Dow Corning
1297~Sl
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Corporation under the trade name Silicone 200 Fluids. Suitable
polydimethylsiloxanes have a viscosity of from about 20 cs to
about 60 000 cs preferably from about 20-1500 cs at 250CC when
used with silica and/or siloxane resin. Other silicone materials
are described in U . S. Patent 4 652 392.
The silicone droplets in the carrier matrix should be from
about 1 to about 100 microns preferably from about 5 to about 40
microns more preferably from about 5 to about 30 microns in
diameter for maximum effectiveness. Droplets below about 5
microns in diameter are not very effective and above about 30
microns in diameter are increasingly less effective. Similar sizes
are required for the other silicone suds controlling agents dis-
closed hereinafter.
A preferred suds controlling agent herein comprises a
hydrophobic silanated (most preferably trimethylsilanated) silica
having a particle size in the range from about 10 millimicrons to
about 20 millimicrons and a specific surface area above about 50
m21g intimately admixed with a dimethyl silicone fluid having a
molecular weight in the range of from about 500 to about 200 000
at a weight ratio of silicone to silanated silica of from about 10:1
to about 1: 2. Such suds controlling agents preferably comprise
silicone and the silanated silica in a weight ratio of sili-
cone:silanated silica of from about 10:1 to about l:l. The mixed
hydrophobic silanated (especially trimethylsilanated) silica-silicone
suds controlling agents provide suds control over a broad range
of temperatures presumably due to the controlled release of the
silicone from the surface of the silanated silica.
Another type of suds control agent herein comprises a
silicone material of the type hereinabove disclosed sorbed onto
and into a solid. Such suds controlling agents comprise the
silicone and solid in a silicone: solid ratio of from about 20: l to
about 1: 20 preferably from about 5: l to about 1: 1. Examples of
suitable solid sorbents for the silicones herein include clay
starch kieselguhr Fuller s Earth and the like. The alkalinity
of the solid sorbents is of no consequence to the compositions
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herein, inasmuch as it has been discovered that the silicones are
stable when admixed therewith. As disclosed hereinabove, the
sorbent-plus-silicone suds controlling agent must be coated or
otherwise incorporated into a carrier material of the type herein-
after disclosed to effectively isolate the silicone from the deter-
gent component of the instant compositions.
Yet another preferred type of silicone suds controlling agent
herein comprises a silicone fluid, a silicone resin and silica. The
silicone fluids useful in such suds controlling mixtures are any of
the types hereinabove disclosed, but are preferably dimethyl
silicones. The silicone "resins" used in such compositions can be
any alkylated silicone resins, but are usually those prepared from
methylsilanes. Sil;cone resins are commonly described/as "three-
dimensional" polymers arising from ~he hydrolysis of alkyl
trichlorosilanes, whereas the silicone fluids are "two-dimensional"
polymers prepared by the hydrolysis of dichlorosilanes. The
silica components of such compositions are microporous materials
such as the fumed silica aerogels and xerogels having the particle
sizes and surface areas hereinabove disclosed.
The mixed silicone fluid/silicone resin/silica materials useful
in the present compositions can be prepared in the manner dis-
closed in U.S. Patent 3,455,839. These mixed materials are
commercially available from the Dow Corning Corporation. Ac-
cording to U.S. Patent 3,455,839, such materials can be described
as mixtures consisting essentially of:
for each 100 parts by weight of a polydimethylsiloxane fluid
having a viscosity in the range from 20 cs. to 1500 cs. at
25C ~
(a) from about 5 to about 50, preferably from about 5 to
about 20, parts by weight of a siloxane resin composed
of (CH3)3SiO112 units and SiO2 units in which the ratio
of the (CH3)35iOl /2 units to the SiO2 units is within
the range of from about 0.6/1 to about 1.2/1; and
251.
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(b) from about 1 to about 10, preferably from about 1 to
about 5, parts by weight of a solid silica gel, pref-
erably an aerogel.
It is to be recognized that the amount of carrier used to
S isolate the silicone suds controlling agent herein from the deter-
gent component of the compositions herein is not critical. It is
only necessary that enough carrier be used to provide sufficient
volume that substantially all the silicone çan be incorporated
therein. Likewise, it is preferred to have sufficient carrier
material to provide for sufficient strength of the resultant granule
to resist premature breakage. Generally, above about a 2 :1,
preferably from about 5 :1 to about 100 :1, more preferably from
about 10:1 to about 40:1, weight ratio of carrier to silicone suds
controlling agent is employed.
The size of the particles of the suds controlling component
used in the present compositions is selected to be compatible with
the remainder of the detergent composition. The suds controlling
components herein do not segregate unacceptably within the
detergent composition. In general, particles with a maximum
dimension of from about 600 to about 2000, preferably from about
800 to about 1600 microns are compatible with spray-dried deter-
gent granules. Therefore, the majority of the particles should
have these maximum dimensions. The majority of the particles
should have a ratlo of the maxlmum to the minimum diameter of
from about 1. 5 : 1 to about 5 : 1, preferably from about 1. 5 : 1 to
about 4:1.
For most purposes, it is preferred to use a sufficient amount
of the silicone suds controlling component in the detergent compo-
sition to provide a concentration of from about 0 . 00059b to about
10P~ by weight of the silicone suds controlling agent in the compo-
sition. A preferred amount of silicone suds controlling agent in
the detergent composition lies within the range of from about
0.002% to about 0.5~6 by weight. Accordingly, the amount of suds
control component will be adjusted, depending upon the amount of
1~97;~51
silicone suds control agent contained therein, to provicie these
desirable percentages of suds control agent.
All of the above patents are incorporated herein by refer-
ence .
The thickness of the flakes herein should be from about
O . 005 inch to about 0 . ~ inch, preferably from about 0 . 01 inch to
about 0 .1 inch, most preferably from about 0. 025 inch to about
0. 05 inch . The flakes of the plastic organic material should be
substantially solidified. This is achieved by use of the wetted
l O belt coolers which quickly cool the sheets or flakes such that the
carrier melt is hardened. With the wetted, or moistened, belt the
flakes cool quicker and maintain a flat configuration better.
The surface of the belt cooler is wetted by dripping,
spraying, or wiping a thin film of the hydrophilic solvent on the
belt prior to, and preferably immediately prior to, the addition of
the plastic organic material described above. The hydrophilic
solvent is preferably selected from the group consisting of water
and low molecular weight hydrophilic solvents such as C1 4
alcohols containing from one to about three hydroxy groups, and
is most preferably tap water.
By "thin film" (of hydrophilic solvent) is meant enough of
the hydrophilic solvent to cause the plastic organic material to lie
flat against the surface of the belt so that the plastic organic
material is more evenly cooled by the belt cooler, thereby forming
dry flakes. Without this invention, the plastic organic material
bubbles and curls once it is applied to the belt cooler, leaving
areas of unsolidified plastic organic material.
Prevlous to this invention, it was found that heating the
water which is sprayed underneath the belt as part of the belt
cooler to a temperature above the temperature at which the plastic
organic material solidifies (approximately 140F for polyethylene
glycol, for example) would reduce but not eiil71inate the curling.
Heating the water also added cost to the manufacturing process.
The water was heated in the first half of the cooling process.
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In the second half, room temperature water was sprayed on the
bottom of the belt to cool the plastic organic material.
More than a "thin film" of water is not desirable because
excess water may be absorbed by the hydrophilic plastic organic
material, interfering with the flaking process. It is preferred
that the thin film of hydrophilic solvent be applied by wiping the
belt with a damp cloth. Most preferably, absorbent cloth should
be used to wet the belt. The absorbent cloth is most preferably
wetted with tap water, wrung out, and used to wipe the belt
immediately before the plastic organic material is added. The belt
is preferably cleaned so that no grease or oil is present on its
surface when the hydrophilic solvent and then the plastic organic
material are applied.
All percentages, parts and ratios herein are by weight
unless otherwise specified .
The following Examples illustrate the compositions herein.
EXAMPLE I
The following compositions are prepared in flake form by
melting the polyethylene glycol and mixing in the silicone or
enzyme component and then cooling on a Sandvik belt cooler
which has a stainless steel surface. The molten material is
formed into a thin, 0.025 to 0.04 inch, sheet and the belt is
evenly wetted with either butanol, wat0r, ethanol or mixtures
thereof at a level of less than about ~% of the material to be
cooled, e. g ., from about 0.1 to about 0.2% . The residence time
on the belt is about .8 minute. The sheet is then broken into
flakes that can be incorporated into detergent compositions.
The compositions are:
A. 95 parts of polyethylene glycol having a molecular
weight of about 8000 ~PEG 8000) and 5 parts of sili-
cone/silica ~Dow QCF2 3282)~
i3. 95 parts of PEG 8000; 1.5 parts of Dow QCF2 3282; and
3.5 parts of C16 fatty acid.
C. 91 parts of PEG 8000 and 9 parts of Dow QCF2 3282.
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D. 95 parts of tallow alcohol polyethoxylate (80) and 5
parts of silicone (Dow DC 2000)~
E. 95 parts of PEG 8000 and 5 parts of silicone (GE Al
9000) .
F. 95 parts of PEG 8000 and 5 parts of an alkaline pro-
tease ( Alcalase ) .
EXAMPLE I I
A composition containing 95 parts of molten polyethylene
glycol having a molecular weight of about 8000 and 5 parts of
10 silicone (Dow Corning QCF 2-3282 fluid) is prepared.
Approximately lO milliliters of this PEG 8000 composition is
added to a large syringe. The contents of the syringe are
discharged onto the middle of a 316 stainless steel plate which is
approximately 1/ 1 6 of an inch thick and measures approximately
15 11 inches by 16 inches. Tap water (at room temperature;
approximately 70F) is continuously being sprayed onto the bottom
of the stainless steel plate using a #3 full jet nozzle (Spraying
Systems #1/8 G3) to simulate a belt cooler. As soon as the PEG
8000 composition is discharged onto the plate, it is manually
20 spread to a thin film (approximately 0.025-0.040 inch) by
spreading with a spatula. Upon contact with the plate, the
molten, opaque PEG 8000 composition bubbles and curls and forms
a whitish, flakey material with unsolidified areas.
The plate is cleaned off and dried and the syringe is refilled
25 with approximately 10 millillters of PEG 8000 composition. The
plate is wiped with a cloth which has been dipped in tap water
and tightly wrung out, so as to leave a thin film of water on the
surface of the plate. The PEG 8000 composition is discharged
onto the middle of the plate and spread as before. Upon
30 spreading on the wetted plate, the thin film of PEG 8000
composition lays flat against the plate and turns from opaque to
white, indicating that it has solidified. There is no curling or
unsolidified material (i.e., no wet spots). These two runs are
repeated with the same results.
* ~ c~ Y~
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Two runs are conducted which are identical to the above
except that hot tap water (approximately 140F) is sprayed on the
bottom of the plate. When the PEG 8000 composition is applied to
the plate and spread, the hot water is turned off and room
temperature (approximately 70F) tap water is sprayed on the
bottom of the plate. This is to simulate a two-stage cooling
process on a continuous belt cooler, where first hot and then
room temperature water is used to "cool" the belt. With the
two-stage cooling, and without the thin film of water on the
surface of the plate, the PEG 8000 composition still shows
unsolidified areas, although it does not curl as much as when
room temperature water only is sprayed on the bottom of the
plate. When the thin film of water is wiped on the surface of the
plate, the results are the same for the two-stage cooling ~hot,
then room temperature) as for the one-stage cooling (room
temperature water only); the PEG 8000 composition does not curl
and is solidified.
EXAMPLE l l I
A composition containing 98~ parts of molten polyethylene
glycol having a molecular weight of about 8000 and 1~ parts of
silicone (Dow Corning QCF 2-3282 fluid) is prepared. This "PEG
8000 composition" is continuously applied from a reservoir via a
weir to a Sandvic continuous belt cooler ~Sandvic Process
Systems, Ind., Totowa, N.J. ).
Just before the weir (approximately 1-2 feet), a 2 inch steel
pipe of approximately the same width as the belt cooler
(approximately 42 inches) is clamped. Foam rubber insulation
(about 1 inch thick) is wrapped around the pipe. Cotton
toweling is wrapped around the foam rubber. The toweling is
wetted with water from municipal water supplies by means of
a copper tubing distribution system rigged over the toweling.
The distribution system allows enough water to drip onto the
toweling to replace water lost by evaporation. Needle valves are
used to control the drips.
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The steel pipe is clamped above the belt so that the toweling
touches the belt and applies a thin film of water to the surface of
the belt as it moves. As the moistened belt moves under the
weir, the PEG 8000 composition is applied. The PEG 8000
s composition lies flat against the moistened belt, allowing it to
solidify evenly as it cools. The belt continues to move over the
cooling area as water is sprayed underneath the belt. By the
time the PEG 8000 composition reaches the end of the cooling
system, it has solidified and falls or is scraped off the belt,
10 forming dry flakes.
Other processes of the invention are obtained when a 2 x 4
inch board without foam rubber insulation is used to hold the
toweling, when any method of applying a thin film of hydrophilic
solvent is used, when any hydrophilic solvent is used, when any
15 molten, water-soluble or water dispersible, non-hygroscopic
plastic organic material is used, and when any belt cooler is
u sed .
WHAT IS CLAIMED 15:
