Note: Descriptions are shown in the official language in which they were submitted.
WO95/03385 2 1 6 7 3 7 4 PCT~S94/07068
STABLE LIQUID DETERGENT COMPOSITIONS
COMPRISING
DIS~ERSIBLE SILICONE ANTIFOAM AGENT
FIELD OF THE INVENTION
The present invention relates to liquid detergent
compositions containing an antifoam agent. More in particular,
the present invention relates to liquid detergent compositions
comprising a dispersible silicone antifoam agent.
BACKGROUND OF THE INVENTION
The present invention relates to a dispersible antifoam
agent containing a silicone for incorporation into
concentrated liquid detergents wherein the antifoam agent
provides a stable, uniform detergent with controlled foaming
behavior.
wo 95to338s 2 1 6 7 3 7 4 PCT/USg4/07068
A defoamer or antifoam agent is a material which, when
added in low concentration to a foaming liquid controls the
foam problem. The defoamer equilibrates the rate of foam
collapse with the rate of foam formation. Such materials, in
addition, remove unsightly and troublesome surface foam,
improve filtration, watering, washing, and drainage, of
various types of suspensions, mixtures, and slurries.
Defoamers have found application traditionally in such areas
of use as the pulp and paper industry, paints and latex,
coating processes, fertilizers, textiles, fermentation
processes, metal working, adhesive, caulk and polymer
manufacture, the sugar beet industry, oil well cement,
cleaning compounds, cooling towers, and in chemical processes
of varied description, such as municipal and industrial
primary and secondary waste water treatment facilities. It is
essential for a defoamer that it be inert and not capable of
reacting with the product or system in which it is used, and
that it have no adverse affect on the product or system.
The inclusion of a silicone defoamer or silicone antifoam
agent in a liquid detergent is not new, however, it is
uncommon. The reason is that it is particularly difficult to
homogeneously disperse antifoam formulations into aqueous
mediums such as liquid detergents. A liquid detergent is a
complex chemical formulation and often the complexity of such
formulations hinder a homogeneous dispersion of an antifoam
composition in the detergent. The result is often loss of
uniformity, as well as flocculates of antifoam accumulating at
the surface of the detergent. One of the overriding trends of
today is the move toward more concentrated liquid detergents.
This shift offers the inherent efficiency of manufacture and
use of liquid formulas, such as pumpability and easy measuring
of liquids, while reducing the burden of packaging and
shipping costs. This trend is occurring in both the consumer
market products and in industrial formulations.
The move toward concentrated liquids usually entails the
reduction of water content in a formulated liquid. This
results in an increase in electrolyte and solids levels in
these liquid detergent formulas. Another change is the
W095/03385 2 1 6 7 3 7 4 PCT~S94/07~8
dependence on non- aqueous solvents to aid in the
solubilization of detergent components such as surfactants.
Both of these changes make stabilization of antifoam droplets
against physical separation and/or aggregation phenomena more
difficult.
Many silicone containing antifoam compositions have been
described in the art. Thus, for example, Rosen, in United
States Patent No. 4,076,648, teaches self-dispersible
antifoam compositions consisting essentially of a lipophilic
nonionic surface active agent homogeneously dispersed in a
non-emulsified diorganopolysiloxane antifoam agent. This
combination is said to promote dispersibility in water without
the need for emulsification.
Sinka et al, in U.S. Patent No. 4,021,365, discloses defoamer
compositions having improved stability which are prepared from
hydrophobic silica, quick-chilled amides, and hydrocarbon oil,
with oil soluble organic polymers and surface active additives
as optional ingredients. The defoamer compositions are
described as being useful in defoaming aqueous systems
including paper pulp black liquors, water-base paints, and
adhesives.
Raleigh, in United States Patent No. 4,005,044 discloses
an antifoam composition and method with a silazane treated
precipitated silica added to aqueous emulsions of silicone oil
with organic nonionic surfactants. Raleigh particularly
emphasizes hexamethyldisilazane-treated silica and teaches
that especially stable emulsions are formed.
Koerner et al., in United States Patent No. 4,274,977,
discloses a defoamer composition having a high dispersion
stability composed of a water-insoluble defoamer oil, a water
soluble emulsifier which is insoluble in the defoamer oil, and
a mixture of a finely divided hydrophobic and hydrophilic
silica. It is taught that the compositions allow for the
production of exceptionally stable dispersions.
Keil, in U.S. Patent No. 3,784,479, discloses foam
control compositions which consist essentially of a base oil
W095/03385 2 1 6 7 3 7 4 PCT~S94107068
~f'
selected from polyoxypropylene
polymers,polyoxypropylene-polyoxyethylene copolymers or
siloxane-glycol copolymers, a foam control agent comprising a
liquid dimethylpolysiloxane and silica filler, and a
dispersing agent which consists of a copolymer of a siloxane
resin and polyoxyalkylene polymer. The contribution to the art
in this case is stated to be improved compatibility with
otherwise desirable diluents without resorting to emulsifying
the foam control agent in water.
In a closely related patent, Keil, in United States
Patent No. 3,984,347, discloses foam control compositions
which consist essentially of a base oil selected from
polyoxypropylene polymers, polyoxypropylene-polyoxyethylene
copolymers or siloxane-glycol copolymers, a foam control agent
comprising a liquid dimethylpolysiloxane and silica filler and
a siloxane copolymer dispersing agent. This time the
dispersing agent consists of a copolymer of a
dimethylpolysiloxane polymer and a polyoxyalkylene polymer.
The same advantages as reported for U.S. Patent No. 3,784,479,
cited supra, were obtained.
Japanese O.P.I. No. 139,107/81, published October 30,
1981, teaches a self-emulsifying type defoaming agent which is
said to have excellent foam-suppressing and breaking
capability regardless of temperature and pH of a liquid to be
treated and the storage period to which it is subjected. This
agent is composed of a silicone copolymer having
diorganosiloxane and organo- oxyalkylenesiloxane units in the
copolymer chain.
Aizawa et al., in United States Patent No. 4,639,489 and
United States Patent No. 4,749,740, the disclosures of which
are hereby incorporated by reference, teach a method for
producing a silicone defoamer composition wherein a complex
mixture of polyorganosiloxanes, filler, a resinous siloxane
and a catalyst-to promote reaction of the other components are
heated together at 50C to 300C.
More recently, a method for preparing a composition
similar to that described by Aizawa et al., cited supra, was
disclosed in Australian Patent Application No. 75771/87,
wo 95,~38~ 2 1 6 73 7 4 PCT~S94/07068
published on January 21, 1988 and assigned to Dow Corning KK,
the disclosure of which is hereby incorporated by reference.
In this disclosure, the abovementioned complex silicone
mixture additionally contains at least 0.2 weight parts of an
organic compound having at least one group selected from COR,
-COOR' or -(OR'')n~, wherein R and R' are hydrogen or a
monovalent hydrocarbon group, R'' is a divalent hydrocarbon
group having 2 to 6 carbon atoms and the average value of n is
greater than one. In this disclosure the inventor, T. Miura,
emphasizes the need to react all the ingredients, including a
catalyst, at elevated temperature to obtain the desired
antifoam agent.
John et al., in European Patent Application No. 217,501,
published April 8, 1987, the disclosure of which is hereby
incorporated by reference, discloses a foam control
composition which gives improved performance in high foaming
detergent compositions which comprises ~A) a liquid siloxane
having a viscosity at 25C of at least 7 x 10 3 m2/s and which
was obtained by mixing and heating a
triorganosiloxane-endblocked polydiorganosiloxane, a
polydiorganosiloxane having at least one terminal silanol
group and an organosiloxane resin, comprising monovalent and
tetravalent siloxy units and having at least one silanol group
per molecule, and (B) a finely divided filler having its
surface made hydrophobic. John et al. further describes a
method for making the foam control compositions and detergent
compositions containing said foam control compositions.
Starch, in U.S. Patent No. 4,983,316 discloses a
dispersible antifoam composition for providing controlled
foaming liquid laundry detergent formulations and wherein
there is provided a non-aqueous emulsion of primary and
secondary silicone antifoam agents, at least one nonionic
silicone surfactant for emulsifying the primary and secondary
antifoaming agents in a solvent, a first organic surfactant
dispersing agent for assisting in dispersing the emulsified
primary and secondary antifoaming agents in the liquid laundry
detergents, and a second dispersing agent of a nonionic
difunctional block-copolymer terminating in primary hydroxyl
wo 95~0338s 2 1 6 7 3 7 4 PCT~S94/07068
groups for further assisting in dispersing the emulsified
primary and secondary antifoam agents in the liquid laundry
detergent. A liquid laundry detergent composition containing
the composition described immediately above is also disclosed.
McGee et al., in European Patent Application No. 341,952,
published November 15, 1989 discloses a combination of the
above mentioned compositions of Aizawa et al. with particular
silicone glycol compounds to provide improved antifoams for
use in high pH aqueous systems, particularly pulp mill
liquors. McGee et al. further describes that addition of a
silica filler has been found to impart increased stability to
the compositions and to dispersions thereof.
Hill et al., in European Patent Application No. 499,364,
published August 19, 1992 teaches a method of foam control
wherein the antifoam agent is an emulsion gelled silicone
composition prepared by first dispersing a curable liquid
organopolysiloxane composition in a liquid continuous phase to
form an emulsion and then curing the liquid silicone
organopolysiloxane in-situ to a gelled state. Hill et al.
further discloses that the compositions of the invention find
particular utility in the control of foam in aqueous detergent
systems.
Difficulties are encountered in delivering silicone
antifoams to highly concentrated surfactant media. Approaches
discussed by Keil and by Starch hereinabove suggest that any
polyglycol can be used, however it has been discovered that,
for some applications, solubility limitations can greatly
hamper the effective dispersion of silicone antifoam
compounds. Careful selection of the continuous phase may
provide improved dispersibility of the antifoam compound, thus
obviating the need for many of the dispersion aids present in
Starch and simplifying the formulas for the emulsion.
In addition, no suggestion in the references above was
made of the stability of the antifoam after it was delivered
to the detergent medium. The present invention centers on the
discovery that, by inclusion of filler materials in the
antifoam compound, there is a large improvement in stability
due to less sedimentation in liquid detergent concentrates
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
that have specific gravities greater than 1.000, and that
certain types of particulate materials can greatly increase
antifoam droplet stability against aggregation during storage.
More importantly the present invention offers a very
dramatic improvement in stability against coalescence and
aggregation in concentrated detergent liquids. In reducing
aggregation, the present invention can improve the uniformity
of dispersion of the antifoam, provide more uniform and
reproducible foam control delivery, and avoid the formation of
unsightly lumps of aggregated antifoam droplets that may tend
to sink or float during storage thus aiding in their stability
and providing a far less visible form of the antifoam allowing
for the formulation of transparent liquids if needed.
Therefore, improved foam control can be obtained if
compositions such as those described in Aizawa et al. are
modified to offer improved combinations of antifoam
compositions, non-aqueous phases, additonal fillers, and
especially through the use of particulate stabilizers.
SUMMARY OF THE INVENTION
In accordance with the present invention, it has been
discovered that a non-aqueous liquid continuous phase and a
moderately hydrophobic particulate stabilizing aid when
combined with and incorporated into an antifoam formulation of
U.S. Patent Nos. 4,639,489, 4,749,740, or EP0217501 cited
supra, render the antifoam dispersible and stable in aqueous
media such as liquid detergents, and especially concentrated
liquid detergents, and therefore solve the problem of
dispersibility of previously disclosed antifoam formulations.
Thus the present invention relates to liquid detergent
compositions comprising an antifoam agent, said agent
consisting essentially of: (I) a reaction product prepared by
reacting at a temperature of 50C to 300C: (i) 100 parts by
weight of at least one polyorganosiloxane selected from the
group consisting of (A) a polyorganosiloxane having a
viscosity of about 20 to 100,000 cS at 25C and being
W095/~385 2 1 6 7 3 7 4 PCT~S94/07068
expressed by the general formula R aSiO(4-a)/2 in which R1 is
a monovalent hydrocarbon or halogenated hydrocarbon group
having 1 to 10 carbon atoms and a has an average value of 1.9
to 2.2 and (B) a polyorganosiloxane having a viscosity of 200
to about 100 million cS at 25C expressed by the general
formula R2b(R O)cSiO(4 b-c)/2 in which R2 is a monovalent
hydrocarbon or halogenated hydrocarbon group having 1 to 10
carbon atoms, R3 is hydrogen or a monovalent hydrocarbon group
having 1 to 10 carbon atoms, b has an average value of 1.9 to
2.2 and c has a sufficiently large value to give at least one
-oR3 group in each molecule, at least one such -OR group
being present at the end of the molecular chain, (ii) 0.5 to
20 parts by weight of at least one silicon compound selected
from the group consisting of (a) an organosilicon compound of
the general formula R4dSiX4 d in which R4 is a monovalent
hydrocarbon group having 1 to 5 carbon atoms, X is selected
from the group consisting of hydroxyl and a hydrolyzable group
and d has an average value of one or less, ~b) a partially
hydrolyzed condensate of said compound (a), (c) a siloxane
resin consisting essentially of (CH3)3SiO1/2 units and SiO4/2
units wherein the ratio of (CH3)3SiO1/2 units to SiO4/2 units
is 0.4:1 to 1.2:1, and (d) a condensate of said compound ~cj
with said compound (a) or (b), (iii) 0 parts by weight or an
amount greater than 0 to 30 parts by weight of at least one
finely divided filler, and (iv) a catalytic amount of a
compound for promoting the reaction of components (i) to
(iii), (II) a nonaqueous liquid continuous phase, and (III) a
moderately hydrophobic particulate stabilizing aid. It is
therefore an object of the present invention to provide an
easily dispersible silicone antifoam composition for use in a
liquid detergent and wherein there is provided controlled
foaming behavior.
It is another object of the present invention to provide
a homogeneously dispersible silicone antifoam formulation for
a liquid detergent or an aqueous medium wherein the antifoam
composition can be dispersed into the liquid detergent or the
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
aqueous medium in order to form stable, relatively uniform
formulations having controlled foaming behavior.
Another object of this invention is to provide a
dispersible silicone antifoam composition offering much
improved stability against aggregation and separation and ease
of dispersibility. It is also an object of this invention to
greatly increase antifoam droplet stability against
aggregation during storage in the highly concentrated liquid
detergent medium. An additional object of this invention is to
improve stability against coalescence and aggregation in
concentrated detergent liquids. A further object of this
invention is to improve the uniformity of dispersion of a
silicone antifoam and avoid the formation of lumps of
aggregated antifoam droplets that may tend to sink or float
during storage.
These and other features, objects and advantages of the
present invention will be apparent upon consideration of the
following detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Antifoam agent
The antifoam agent of this invention consists essentially
of (I) a reaction product prepared according to the disclosure
of Aizawa et al., cited supra, (II) a nonaqueous liquid
continuous phase, and (III) a moderately hydrophobic
particulate stabilizing aid.
Component (I) of the antifoam agent according to the
present invention is a reaction product of (i) a
polyorganosiloxane, (ii) a silicon compound, (iii) at least
one finely divided filler and (iv) a catalytic amount of a
compound for promoting the reaction of the other components.
Component (i) may be selected from (A)
polyorganosiloxanes expressed by the general formula
R1aSiO(4 a)/2 and having a viscosity of 20 to 100,000
centistokes (cS) at 25C. The organo groups R of the
WO95/03385 2 1 6 7 3 7 4 PCT~S94107068
/~
polyorganosiloxane (A) are the same or different monovalent
hydrocarbon or halogenated hydrocarbon groups having one to
ten carbon atoms. Specific examples thereof are well known in
the silicone industry and include methyl, ethyl, propyl,
butyl, octyl, trifluoropropyl, phenyl, 2-phenylethyl and vinyl
groups. The methyl group is particularly preferred. In the
above formula, a has a value of 1.9 to 2.2. It is
particularly preferred that polyorganosiloxane (A) is a
trimethylsilyl- terminated polydimethylsiloxane having a
viscosity of about 350 to 15,000 cS at 25C.
Alternatively, component (i) may be selected from (B)
polyorganosiloxanes expressed by the general formula
R b(R O)cSiO(4-b-c)/2 and having a viscosity of 200 to 100
million centistokes at 25C wherein R2 is independently
selected from the monovalent hydrocarbon or halogenated
hydrocarbon groups designated for group R1, R3 is a hydrogen
atom or R2, and the -oR3 group is present at least at one end
of the molecular chain of the polyorganosiloxane. The value
of b is between 1.9 to 2.2 and c is has a value so as to
provide at least one -OR group per molecule. It is
particularly preferred that polyorganosiloxane (B) is a
hydroxyl-terminated polydimethylsiloxane having a viscosity of
about 1,000 to 50,000 cS at 25C. Component (i) may also be a
mixture of (A) and (B) in any proportion.
Component (ii) is at least one silicon compound selected
from (a) to (d), (a) an organosilicon compound of the general
formula R4dSiX4 d wherein R4 is a monovalent hydrocarbon group
having one to five carbon atoms, X is a hydrolyzable group,
such as -oR5 or - oR6oR7, in which R6 is a divalent
hydrocarbon group having one to five carbon atoms and R5 and
R7 are each hydrogen or a monovalent hydrocarbon group having
one to five carbon atoms, the average value of d not exceeding
1; (b) a partially hydrolyzed condensate of the compound (a);
(c) a siloxane resin consisting essentially of (CH3)3SiO1/2
and SiO2 units and having a (CH3)3SiO1/2/SiO2 ratio of 0.4/1
to 1.2/1; and (d) a condensate of the siloxane resin (c) with
the compound (a) or (b).
wo 95~38s 2 1 6 7 3 7 4 PCT~S94/07068
It is preferred that component (ii) is selected from
either an alkyl polysilicate wherein the alkyl group has one
to five carbon atoms, such as methyl polysilicate, ethyl
polysilicate and propyl polysilicate, or the siloxane resin
~c), Most preferably, component (ii) is either ethyl
polysilicate or a siloxane resin copolymer consisting
essentially of (CH3)3SiO1/2 units and SiO2 units in a molar
ratio of 0.4:1 to 1.2:1.
Component (iii) is optional and is at least one finely
divided filler such as fumed TiO2, A12O3, A12O3/SiO2,
ZrO2/SiO2 and SiO2. Silica (SiO2) can be produced by a dry
method such as the thermal decomposition of a silicon halide
or the reaction of a substance containing silicic acid under
heat, or silica can be produced by a wet method such as the
decomposition of a metal salt of silicic acid, e.g., sodium
silicate, by an acid or the aerogel method. Various grades of
silica having a particle size of several millimicrons to
several microns and a specific surface area of about 50 to 500
m2/g are commercially available and suitable for use as
component (iii). Preferably, the filler is selected from
silicas having a surface area of about 50 to 300 m2/g. Fumed
TiO2, Al2O3, and Al2O3/SiO2 can be prepared by the well-known
process of burning TiCl4, AlCl3, and SiC14 and mixtures
thereof. Specific examples of this filler include zirconium
silica hydrogels, and hydrophilic or hydrophobic silica. For
purposes of the present invention the term r'finely divided
filler" excludes materials such as mined quartz or micronized
quartz.
Preferably the finely divided filler is a compatiblized
filler such as hydrophobically modified finely divided silica
which has been modified by surface reaction with any of the
various treating agents to produce a well treated, hydrophobic
surface. This can be accomplished in-situ or by prior
treatment.
Component (iii) can be 0 parts by weight in Reaction Product
(I) or can be from greater than zero to 30 parts by weight per
100 parts by weight of Reaction Product (I).
wo 95/03385 2 1 6 7 3 7 4 PCT~S94/07068
Component (iv) is a compound used as a catalyst for
promoting the reaction of the other components. It is
preferably selected from siloxane equilibration and/or
silanol-condensing catalysts such as alkali metal hydroxides,
alkali metal silanolates, alkali metal alkoxides, quaternary
ammonium hydroxides and silanolates, quaternary phosphonium
hydroxides and silanolates and metal salts of organic acids.
It is preferred that the catalyst is potassium silanolate.
For the purposes of the present invention, the reaction
product may optionally contain component (v), a polyorgano-
siloxane expressed by the general formula
R8e(R9O)fSiO(4 ~ f)/2 and having a viscosity of 5 to 200 cS at
25C wherein R is a monovalent hydrocarbon or halogenated
hydrocarbon group having one to ten carbon atoms and R9 is
hydrogen or a monovalent hydrocarbon group having one to ten
carbon atoms. The value of e is between 1.9 and 2.2 and f has
a value so as to provide two or more -OR groups in each
molecule. It is particularly preferred that component (v) is
a hydroxyl-terminated polydimethylsiloxane having a viscosity
of about 10 to 50 cS at 25C. It is preferred that component
(v) is added when filler (iii) is a hydrophilic silica.
A mixture of components (i) to (iv), optionally
containing component (v), is reacted under heat to produce the
reaction product, the proportions of the various components
being:
Component (i) - 100 parts by weight;
Component (ii) - 0.5 to 20, preferably 1 to 7, parts
by weight;
Component (iii) - 0 parts by weight, or from greater
than 0 to 30, preferably 1 to 15, and
highly preferred is 5 to 15 parts by
weight;
Component (iv) - A catalytic amount (usually in the
range of 0.03 to 1 part by weight);
Component (v) - 0 to 20, preferably 1 to 10, parts
by weight.
21 67374
WO95l03385 PCT~S94/07068
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The proportlons of components (A) and (B) used depends largely
on their respective viscosities. It is prefexable to use a
mixture of (A) and (B) which has a viscosity of 1,000 to
100,000 cS at 25C.
The reaction product (I) is prepared by first mixing
components (i) and (ii) and heating this blend to about 110 to
120C and then adding catalyst (iv). Finely divided filler
(iii), if desired, is then uniformly mixed in using an
appropriate dispersing device, such as a homomixer, colloid
mill or triple roll mill. The resulting mixture is heated at
a temperature of 50C to 300C, preferably 100C to 300C, and
reacted for one to eight hours, although the reaction time
varies depending on the temperature. If component (v) is to
be employed in the composition, it is generally added after
the filler (iii). It is preferable to carry out all mixing
and heating operations in an inert gas atmosphere in order to
avoid any danger and to remove volatile matter (unreacted
matter, by-products, etc.). The mixing order of the
components and the heating temperature and time as hereinabove
stated are not believed critical, but can be changed as
required. It is further preferred that, after reaction, the
catalyst is neutralized to further stabilize reaction product
(I). Alternatively, reaction product (I) preferably comprises
a diorganopolysiloxane and a silicon compound, this
combination optionally containing a filler such as silica.
These systems contain a mixture of a trimethylsilyl-
terminàted polydimethylsiloxane and a diorganopolysiloxane
having silicon- bonded hydroxyl groups or silicon-bonded
alkoxy groups along its main chain or at its chain ends, said
alkoxy groups having from 1 to 6 carbon atoms. The silicon
compound (ii) acts as a crosslinker for the
diorganopolysiloxane by reacting with the functionality of the
latter. It is further preferred that the above
diorganopolysiloxane is either a linear or a branched polymer
or copolymer of siloxane units selected from dimethyl-siloxane
units, methylphenylsiloxane units or methyltrifluoro-
propylsiloxane units. Most preferably, the
diorganopolysiloxane of component (A) is a
W095t03385 2 1 6 7 3 7 4 PCT~S94/07068
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polydimethylsiloxane contalning Si-bonded hydroxyl or methoxy
functionality. The above mentioned silicon compound (ii) is
preferably a siloxane resin consisting essentially of
(CH3)3SiO1/2 and SiO2 units and having a molar ratio of
(CH3)3SiO1/2/SiO2 between 0.4:1 and 1.2:1. The latter resin
may be prepared according to methods taught in, e.g., United
States Patent No. 2,676,182 to Daudt et al. and typically
contains from about 0.5 to about 3 weight percent of hydroxyl
groups.
A highly preferred component (I) is a homogeneous blend
of a hydroxyl-terminated polydimethylsiloxane and a a
trimethylsilyl- terminated polydimethylsiloxane having a
viscosity in the range of about 1,000 to 50,000 cS at 25C, a
siloxane resin having a molar ratio of (CH3)3SiO1/2/SiO2 units
of from 0.4:1 to 1.2:1, and a potassium silanolate catalyst
reacted at a temperature of 50 to 300C.
The nonaqueous liquid continuous phase (II) of the
antifoam agent according to the present invention may be a
non-reactive organic composition. The term "non-reactive" is
intended to convey the restriction that this component be
generally compatible with the silicone antifoam (I), as
detailed above. Since component (II) is designed to be a
distinct phase, its character is further restricted to liquids
which are essentially immiscible with the particular silicone
antifoam (I). The nonaqueous liquid continuous phase of
component (II) can be selected from the group consisting of
ethylene glycol, propylene glycol, polypropylene glycol,
polyethylene glycol, copolymers of either a random or block
type, of propylene and ethylene glycols and condensates with
polyols such as glycerol. Additional nonaqueous liquid phases
of this invention include a wide range of nonionic organic
surfactants such as alcohol alkoxylates or alkylphenol
alkoxylates.
The nonaqueous phase is selected for ease of
dispersibility and solubility in the liquid detergent medium
since insufficient solubility can lead to poor stability and
poor performance of the antifoam in the liquid detergent.
WO95/03385 2 1 6 7 3 7 4 PCT~S94/07068
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Consideration is also made for compatibility of the liquid
with the nonionic silicone surfactants which may be used in
preparing the antifoam emulsion described hereinbelow. The
liquids are further selected based on their specific gravity
with a close match relative to the antif3am particles being
preferable. Preferably, component (II) has a viscosity below
about 10,000 cS at 25C. A closer match of the continuous
phase specific gravity to the antifoam droplets may be
obtained by judiciously selecting and blending two or more
nonaqueous liquids to make component (II). It is preferable
that about 25 to 900 parts by weight of liquid continuous
phase (II) be used per 100 parts by weight of defoamer
reaction product (I). It is highly preferred for purposes of
the present invention that 100 to 400 parts by weight of
liquid continuous phase (II) be used per 100 parts by weight
of defoamer reaction product (I).
Component (III) of the antifoam agent according to the
present invention is a moderately hydrophobic particulate
stabilizing aid wherein the particulate is a very fine
particle size silica. Typically component (III) of the
present invention is silica and is of the fumed or
precipitated types but not limited to this type, having a
B.E.T. surface area preferably from 50 to 500 square meters
per gram, the surface of which has been incompletely treated
with hydrophobing agents.
One important measure of the hydrophobing treatment level
is the analysis of bound carbon on the silica. The great
majority of hydrophobing agents used today incorporate carbon
as a critical component of their hydrophobic groups and as
such carbon contributes directly to the hydrophobic layer on
the silica surface. We have found that in comparing silicas
of different surface areas it is necessary to normalize the
amount of bound carbon with respect to the total surface area
of the treated silica, as measured by the nitrogen B.E.T.
technique, to obtain a useful comparison. For the sake of
this document we have used the term Specific Loading to
describe the micrograms of carbon bound per square meter of
surface area. The bound carbon may be measured by any of a
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
/~
number of analytical techniques but should be a directly
measured value. This comparison is especially useful when the
treatment agent and treatment conditions is the same among a
series fo samples to be judged on their hydrophobicity. It is
also assumed in making this comparison that the relative
number of surface silanols is not affected by any other
treatments such as roasting at elevated temperatures, etc.,
which will impact the hydrophilicity of untreated regions. It
should be noted that the type of carbon deposited on the
surface and its distribution on the surface will have a major
impact on the level of hydrophobicity. One measure of
treatment level is determined using the Methanol Wettability
test. This is a standard test known in the industry which
measures the volume percent of methanol in water needed to
just wet the silica. Silicas that are wettable by solutions
containing less methanol are more hydrophilic, those requiring
more methanol are more hydrophobic.
For example, one embodiment of component (III) that has
shown good utility in the present invention is Aerosil R 972
(fumed silica that has been treated to a moderate level with
dichlorodimethylsilane, having about 110 m2/g BET surface
area, Degussa Corporation, Ridgefield Park, N.J.). This
material is prepared from a fumed silica having surface area
of 130 m2/g. The silica is treated with
dimethyldichlorosilane at about 500C with the treating level
being controlled to provide less than complete methylation of
the surface. In the case of AerosilR R 972 it is estimated
that 70% of the surface hydroxyl groups present on the
original silica have been methylated leaving approximately 30
% untreated. Thus, this silica has a 70/30 or a 2.33
treated/untreated silanol ratio. We can also calculate a
Specific Loading for this silica of 91 micro grams of carbon
per square meter based on the analysis of about 1.0 wt.% bound
carbon (0.01 g Carbon/g Silica) and 110m2 /g of the treated
silica. The untreated hydroxyls are hydrophilic and are
capable of hydrogen bonding with polar substances such as
water. The alkylated portion of the surface is non-polar in
nature and hydrophobic. A controlled level of treatment will
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
provide a moderately treated silica with a balance between the
hydrophobic alkylated surface and the hydrophilic untreated
surface. Particulates having a controlled level of hydrophobic
treatment prior to utilization are preferred as component
(III) in the present invention.
Any of several known treating methods may be employed in prior
treatment of the silica for component (III). For example in a
preferred embodyment fumed silica can be treated with
dimethyl-dichlorosilane to affix dimethylsilane groups on the
surface of the silica. The hydrophobing agents herein are any
of those well known to the art which provide organosilyl
reaction products bound to the silica surface. Common
examples of hydrophobing agents are silanes, siloxanes, or
silazanes. Thus, modification is carried out by procedures
well known to the art, for example, by reaction of the silica
surface with
trialkylchlorosilane,dialkyldichlorosilane,octaalkylcyclotetra
siloxane, or hexaalkyldisilazane, or hexaalkyltrisilazane
under suitable conditions. Hydrophobing agents such as
polydimethylsiloxane are not preferred for this invention
unless special care is taken to limit the amount of
hydrophobic material placed on the silica surface and its
distribution.
It is preferred that for the compositions of the present
invention that the stabilizing aid of component (III) be a
silica whose surface has been hydrophobically modified to
provide a surface composition having a treated/untreated
surface silanol ratio such that it has a Methanol Wettability
of from 30 to 70 percent. It is highly preferred in the
present invention that component (III) have a Methanol
Wettability of from 35 to 55 percent.
Other characteristics of the silica of component (III)
are hypothesized to have influencing factors on their relative
utility as stabilizing aids. Without limiting the present
invention to any particular theory, it is believed that the
physical and chemical makeup of the solid's surface is
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
important to the utility of the particulates in the present
invention in that it controls the wetting behavior of the
solid. Thus, in addition to having a controlled level of
surface treatment, the uniformity of distribution of the
hydrophobic materials on the surface and the surface roughness
and porosity of the solid is thought to impact wetting
behavior, especially wetting hysteresis.
The manner in which the particulates are assembled is
also thought to influence their utility. For example, silicas
are thought to consist of primary particles linked together
into aggregates which are assembled into agglomerates through
physical interactions. Breakup of agglomerates into smaller
particles may be one component in the relative efficiency of
the particulate stabilization and should be a component of
processing optimization.
An effective amount of the stabilizing aid of the present
invention is required for the compositions of the present
invention to display beneficial effects in liquid detergent
systems. However, it is preferable that about 0.1 to 250
parts by weight of stabilizing aid be used per 100 parts by
weight of defoamer reaction product (I). It is highly
preferred for purposes of the present invention that 0.3 to
125 parts by weight of stabilizing aid be used per 100 parts
by weight of defoamer reaction product (I).
Optionally the antifoam agent according to the present
invention additionally comprise (IV) at least one nonionic
silicone surfactant. The nonionic silicone surfactant is
preferably a material including a trimethylsilyl endcapped
polysilicate which has been condensed with a polyalkylene
glycol or diester in a solvent, or a block copolymer of
polydimethylsiloxane and polyalkylene oxide. Typically a
sufficient quantity of at least one nonionic silicone
surfactant is employed to aid emulsification of silicone
antifoam component (I) described hereinabove in the nonaqueous
liquid continuous phase component (II) described hereinabove.
Generally, from about 1 to 40 parts by weight of surfactant is
used for each 100 parts by weight of component (I). These
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
/~
surfactants are well known in the art and are exemplified by
the "dispersing agents" disclosed by Keil in United States
Patent numbers 3,784,479 and 3,984,347, the disclosures of
which are hereby incorporated by reference to teach said
surfactants. In some instances the surfactants may best be
processed from a solvent such as a polyalkylene glycol or
copolymers thereof, cyclic silicones, or an organic solvent
such as xylene.
The antifoam agent according to the present invention may
also additionally comprise (V) a level of a nonreinforcing
inorganic filler mixed internally to component (I) to increase
its density to match the density of component (II) or of the
liquid detergent, and thus to reduce the rate of settling of
antifoam particles in the liquid medium. Preferably the
nonreinforcing inorganic filler is added to component (I)
after the reaction is complete as it is cooling.
A wide variety of materials may be used as an inorganic
filler. Specific examples of these materials are ground,
micronized, or seived inorganic compounds or minerals either
naturally occurring or artificial. One requirement is that
the particle size be small relative to the antifoam droplets
to provide for more uniform density distribution between
droplets. To attain high densities needed for maximum
efficiency, very dense or crystalline materials may be
preferred.
Preferred as the nonreinforcing inorganic filler (V) for the
antifoam agents according to the present invention are
Min-u-sil ground crystalline silicas (available from U.S.
Silica Company, Berkeley Springs, WV), microcystalline
novaculite such as NovaciteR or surface modified forms such as
Novakup (Malvern Minerals Company Hot Springs National Park,
AR), calcium carbonate, antimony oxides, wollastonite,
titanium oxides or their surface modified forms available
commercially as CarbokupR, MonykupR, WollastokupR, or Trikup ,
(Malvern Minerals Company, Hot Springs National Park, AR). In
addition, diatomaceous earth, clays, zinc oxides such as Azo
77 or Azo 77TT from Asarco Inc. (Hillsboro, IL) or Barium
2167374
W095/0338~ PCT~S94107068
sulfate such as 2278 Blanc Fixe or 106 Lo Micron White Barytes
S.F. from Wittaker Clark and Daniels Inc. (South Plainfield,
N.J.) may be used as inorganic filler (V) in the compositions
of the present invention however this list is not exhaustive.
Alternatively, higher levels of finely d vided filler (iii)
described hereinabove normally used in antifoams, may be used
at levels higher than necessary just for antifoaming efficacy,
reducing or obviating the need for an additional
nonreinforcing filler. An additional advantage in clarity or
appearance of the defoaming component may be realized. This
approach may be limited by any loss in antifoam efficacy due
to overloading of the reaction product compound. Another
limiting factor in this approach is that addition of large
amounts of these materials will increase the viscosity of the
defoaming component (I) and may hinder processing,
emulsification, and/or performance of the antifoam.
In addition to the above mentioned components, the foam
control agents of the present invention may also contain
adjuvants such as corrosion inhibitors and dyes.
The antifoam agent according to the present invention may
be prepared by homogeneously mixing, without heating or
further catalysis, components (I), (II), and (III) and any
optional components, using any suitable mixing means such as a
spatula, mechanical stirrers, in-line mixing systems
containing baffles, blades, or any of the like mixing surfaces
including powered in-line mixers or homogenizers, a drum
roller, a three-roll mill, a sigma blade mixer, a bread dough
mixer, and a two roll mill.
The order of mixing components (I) to (III) is not
critical, however it is highly preferred that components (I)
and (III) not -be premixed together. After component (I) and
nonaqueous liquid continuous phase (II) are mixed, component
(III) is combined with the mixture of components (I) and (II)
to form an emulsion and to form a composition of the present
invention. The particulate stabilizing aid (III) may be
W095/03385 2 1 6 7 3 7 4 PCT~Sg4/07068
~/
combined with the mixture of (I) and (II) either as a dry
powder or as a premix in a portion of component (II).
The method described hereinabove is not limiting however.
Another method for preparing the antifoam agent according to
the present invention involves mixing components (II) and
(III) together, and next combining component (I) with the
mixture formed by (II) and (III). It is preferred that the
stabilizing aid component (III) not be mixed into the silicone
antifoam component (I) directly as this may cause the
stabilizing aid to lose its hydrophilic character and thus
reduce the effectiveness of the antifoam agent according to
the present invention.
The present invention further relates to an antifoam
agent prepared by mixing (I) a reaction product, (II) a
nonaqueous liquid continuous phase, and (III) an effective
amount of a particulate stabilizing aid, with the proviso that
components (I) and (III) are not mixed together without the
presence of component (II). In this aspect of the invention
the reaction product, nonaqueous liquid continuous phase, and
particulate stabilizing aid are as delineated above including
preferred embodiments thereof. The amounts are also as stated
hereinabove.
Optional component (IV), i.e. at least one nonionic
silicone surfactant, may be added separately to Component (I),
tII), or (III), or to any combination of components (I), (II),
or (III), or to the final emulsion of (I), (II), and (III).
Preferably optional Component (V), the nonreinforcing
inorganic filler, is added to component (I) after the reaction
is complete as it is cooling.
The present invention also relates to a method of making
a silicone antifoam comprising the steps of mixing (I) a
reaction product, (II) a nonaqueous liquid continuous phase,
and (III) a moderately hydrophobic particulate stabilizing
- aid, with the proviso that components (I) and (III) are not
mixed together without the presence of component (II). In the
method of the present invention, components (I), (II), and
wo 95/~385 2 1 6 7 3 7 4 PCT~S94/07068
(III) are as delineated above includlng preferred embodiments
thereof. The amounts are also as stated hereinabove.
Again, optional component (IV), i.e. at least one
nonionic silicone surfactant, may be added separately to
Component (I), (II), or (III), or to any combination of
components (I), (II), or (III), or to the final emulsion of
(I), (II), and (III).
Preferably, optional component (V), the nonreinforcing
inorganic filler, is added to component (I) after the reaction
is complete as it is cooling.
Detergent compositions
According to the present invention, a liquid detergent
composition is provided comprising the compositions (I), (II)
and (III), optionally (IV) and/or (V) mixed with detergent
ingredients such as surfactants, builders and other optional
ingredients.
A wide range of surfactants can be used in the detergent
composition of the present invention.
A typical listing of anionic, nonionic, ampholytic and
zwitterionic classes, and species of these surfactants, is
given in US Patent 3,664,961 issued to Norris on May 23, 1972.
One class of nonionic surfactants useful in the present
invention are condensates of ethylene oxide with a hydrophobic
moiety to provide a surfactant having an average hydrophilic-
lipophilic balance (HLB) in the range from 8 to 17, preferably
from 9.5 to 13.5, more preferably from 10 to 12.5. The
hydrophobic (lipophilic) moiety may be aliphatic or aromatic
in nature and the length of the polyoxyethylene group which is
condensed with any particular hydrophobic group can be readily
adjusted to yield a water-soluble compound having the desired
degree of balance between hydrophilic and hydrophobic
elements.
WO95/03385 2 1 6 7 3 7 4 PCT~S94/07068
Especially preferred nonionic surfactants of this type are
the Cg-C1s primary alcohol ethoxylates containing 3-8 moles of
ethylene oxide per mole of alcohol, particularly the C14-Cls
primary alcohols containing 6-8 moles of ethylene oxide per
mole of alcohol and the C12-C14 primary alcohols containing 3-
5 moles of ethylene oxide per mole of alconol.
Another class of nonionic surfactants comprises alkyl
polyglucoside compounds of general formula
RO (CnH2nO)tzx
wherein Z is a moiety derived from glucose; R is a saturated
hydrophobic alkyl group that contains from 12 to 18 carbon
atoms; t is from 0 to 10 and n is 2 or 3; x is from 1.3 to 4,
the compounds including less than 10% unreacted fatty alcohol
and less than 50% short chain alkyl polyglucosides. Compounds
of this type and their use in detergent are disclosed in EP-B
0 070 077, 0 075 996 and 0 094 118.
Also suitable as nonionic surfactants are poly hydroxy fatty
acid amide surfactants of the formula
R2 - C - N - Z
Il I
O Rl
wherein R1 is H, or R1 is C1_4 hydrocarbyl, 2-hydroxy ethyl,
2-hydroxy propyl or a mixture thereof, R2 is Cs_31
hydrocarbyl, and Z is a polyhydroxyhydrocarbyl having a linear
hydrocarbyl chain with at least 3 hydroxyls directly connected
to the chain, or an alkoxylated derivative thereof.
Preferably, R1 is methyl, R2 is a straight C11_1s alkyl or
alkenyl chain such as coconut alkyl or mixtures thereof, and Z
is derived from a reducing sugar such as glucose, fructose,
maltose, lactose, in a reductive amination reaction.
The compositions according to the present invention may
further comprise a builder system. Any conventional builder
wo gs/03385 2 1 6 7 3 7 4 PCT~S94/07068
system is suitable for use herein including aluminosilicate
materials, silicates, polycarboxylates and fatty acids,
materials such as ethylenediamine tetraacetate, metal ion
sequestrants such as aminopolyphosphonates, particularly
ethylenediamine tetramethylene phosphonic ~cid and diethylene
triamine pentamethylenephosphonic acid. Though less preferred
for obvious environmental reasons, phosphate builders can also
be used herein.
Suitable builders can be an inorganic ion exchange material,
commonly an inorganic hydrated aluminosilicate material, more
particularly a hydrated synthetic zeolite such as hydrated
zeolite A, X, B or HS.
Another suitable inorganic builder material is layered
silicate, e.g. SKS-6 (Hoechst). SKS-6 is a crystalline
layered silicate consisting of sodium silicate (Na2Si2Os).
Suitable polycarboxylates builders for use herein include
citric acid, preferably in the form of a water-soluble salt,
derivatives of succinic acid of the formula R-
CH(COOH)CH2(COOH) wherein R is C10-20 alkyl or alkenyl,
preferably C12-16, or wherein R can be substituted with
hydroxyl, sulfo sulfoxyl or sulfone substituents. Specific
examples include lauryl succinate , myristyl succinate,
palmityl succinate2-dodecenylsuccinate, 2-tetradecenyl
succinate. Succinate builders are preferably used in the form
of their water-soluble salts, including sodium, potassium,
ammonium and alkanolammonium salts.
Other suitable polycarboxylates are oxodisuccinates and
mixtures of tartrate monosuccinic and tartrate disuccinic acid
such as described in US 4,663,071.
Especially for the liquid execution herein, suitable fatty
acid builders for use herein are saturated or unsaturated C10-
18 fatty acids, as well as the corresponding soaps. Preferred
saturated species have from 12 to 16 carbon atoms in the alkyl
chain. The preferred unsaturated fatty acid is oleic acid.
Another preferred builder system for liquid compositions is
based on dodecenyl succinic acid.
Other suitable water-soluble organic salts are the homo- or
co-polymeric acids or their salts, in which the polycarboxylic
W095/~385 2 1 6 7 3 7 4 PCT~S94/07068
acid comprises at least two carboxyl radicals separated from
each other by not more than two carbon atoms.
Polymers of this type are disclosed in GB-A-1,596,756.
Examples of such salts are polyacrylates of MW 2000-5000 and
their copolymers with maleic anhydride, such copolymers having
a molecular weight of from 20,000 to 70,030, especially about
40,000.
Detergency builder salts are normally included in amounts of
from 10% to 80% by weight of the composition preferably from
20% to 70% and most usually from 30% to 60% by weight.
Other components used in detergent compositions may be
employed, such enzymes and stabilizers or activators
therefore, soil-suspending agents, soil-release agents,
optical brighteners, abrasives, bactericides, tarnish
inhibitors, coloring agents, and perfumes.
Preferably, the liquid detergent compositions according to
the present invention can also be in "concentrated form", in
such case, the liquid detergent compositions according to the
present invention will contain a lower amount of water,
compared to conventional liquid detergents.
Typically, the water content of the concentrated liquid
detergent is less than 30% , more preferably less than 20%,
most preferably less than 10% by weight of the detergent
composition.
Antifoam compositions prepared in accordance with the present
invention were prepared and tested in order to demonstrate
their defoaming capabilities and to determine stability and
performance of the antifoam compositions.
The compositions of the present invention were tested in
a concentrated liquid detergent.
The following concentrated liquid detergent compositions
were made : t see TABLE 1)
W095/~385 2 1 6 7 3 7 4 PCT~S94/07068
~6
C12-C1s Alkyl sulfate 19.0
C12-C1s Alkyl ethoxylated sulfate 4.0
C12-C14 N-methyl glucamide 9.0
C12-C14 fatty alcohol ethoxylate 6.0
C12-C16 Fatty acid 6.8
Brightener FWA-36
Polyvinyl pyrrolidone 1.0
citric acid anhydrous 4.5
Diethylene triamine penta methylene
phosphonic acid 1.0
Monoethanolamine ~ 12.7
Propanediol 14.5
Ethanol 1.8
Enzymes 2.4
Terephtalate-based polymer 0.5
Boric acid 2.4
2-butyl-Octanol 2.0
Water & Minors ------up to 100%------
TABLE 1: Con~erltrated liquid detergent ro~osition
In the examples, the antifoam agents according to the
present invention and the comparative compositions were tested
for Collar, Aggregation, and Stability. Collar denotes the
thickness of the antifoam layer collected on top of the liquid
detergent around the perimeter of the bottle. Aggregation
denotes the collection of individual antifoam droplets into
flocculates or clumps that are visible by the human eye and
suspended in the body of the liquid. Stability denotes an
overall description of the emulsion stability against
association with the bottle walls and the uniformity of
emulsion distribution in the sample.
wo gs/0338s 2 1 6 7 3 7 ~ PCT~S94/07068
EXAMPLES
The following examples are presented to further
illustrate the method and compositions of this invention, but
are not to be construed as limiting the lnvention, which is
delineated ln the appended clalms. All parts and percentages
ln the examples are on a welght basls and all measurements
were made at 25 C unless lndlcated to the contrary.
The followlng materlals, llsted for ease of
reference, were employed ln the preparatlon of the antlfoam
compositions: ~
POLYORGANOSILOXANE A is a trlmethylsllyl endblocked
polydlmethylsiloxane having a vlscoslty of 1,000 Cs at 25C
POLYORGANOSILOXANE B ls a hydroxyl-termlnated polydlmethyl-
siloxane having a viscosity of approxlmately 13,500 cS at
25C.
CONTINUOUS PHASE I ls P15-200R whlch is an ethylene oxide/
propylene oxide triol copolymer with glycerin having a
molecular weight of about 2,600 from Dow Chemical Company
(Midland, Michigan).
CONTINUOUS PHASE II is NEODOLR 25-7, an organic alcohol
ethoxylate from Shell Chemlcal Chemlcal Company, (Houston,
Texas).
CONTINUOUS PHASE III ls PEG 300, a polyethylene glycol havlng
an average molecular weight of 300 from the Dow Chemlcal
Company, (Mldland, Michigan).
CATALYST I= A mixture of 90 g of lsopropyl alcohol and 10 g of
KOH mixed at 80C for 20 minutes.
RESIN I = A 70% xylene solution of a hydroxy-functional
siloxane resin copolymer consisting essentially of
(CH3)3SiOl/2 and SiO2 units havlng a (CH3)3SiOl/2 /SlO2 ratlo
of about 0.75:1.
FINELY DIVIDED FILLER I ls SIPERNATR D10 ls a hydrophoblc
slllca from Degussa Corp (Rldgefield Park, N.J.).
FINELY DIVIDED FILLER II ls QUSO WR 55 ls a hydrophoblc
preclpltated slllca from Degussa Corporatlon (Rldgefleld Park,
N.J.).
W095/~385 2 1 6 7 3 7 4 PCT~S94/07068
STABILIZING AID I is AEROSIL R 972 a fumed silica that has
been treated to a moderate level with dichlorodimethylsilane,
having about 110 m /g BET surface area, having a methanol
wettability of about 45~ and is from Degussa Corp.
(Ridgefield Park, N.J.). NONREINFORCING FILLER I is MIN-U-SIL
QUARTZ a micronized quartz having the majority of its
particles smaller than 5 microns sold under the trade name
Min-u-sil 5 by U.S. Silica Company (Berekely Springs, WV).
P 4000 is a polypropylene glycol of about 4000 molecular
weight from Dow Chemical Company (Midland, Mi).
TRITON X-100 is an octylephenolxyethoxy(10)ethanol nonionic
surfactant having an HLB of 13.5 and from Rohm and Hass,
(Philadelphia, PA).
PLURONIC L-101 is a block coplymer surfactant of ethylene
oxide and propylene oxide having an HLB of 1 from BASF,
(Parsippany, N.J.).
SURFACTANT 1 = A nonionic silicone surfactant of
trimethylsilyl endcapped polysilicate prepared according to
methods described by Keil in United States Patent No.
3,784,479. A mixture of 7 parts of RESIN I (supra) , 15 parts
of a copolymer of ethylene oxide and propylene oxide having a
molecular weight of about 4,000, and 38 parts of xylene was
reacted at reflux for 8 hours with 0.2 part of a stannous
octoate, 0.1 parts of phosphoric acid was added and the
product was blended with 40 parts of a polyethylene glycol-
polypropylene glycol copolymer. The product was stripped at 40
mm Hg at 140C to remove xylene and filtered.
SURFACTANTS 2-5 are block copolymers of polydimethylsiloxane
and polyalkylene oxide having the average structure, shown
below, were used alone or as present in a solvent:
Me
I
Me3SiO(SiO)j(Me2SiO)kSiMe3
I
CH2cH2cH2(ocH2cH2)m(ocH2c )n
I
Me
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
~9
wherein Me denotes methyl radical, and and the values of j, k,
m, n, are shown in Table I hereinbelow.
TABLE I
Surfactant k i m n z Solvent
Nu~er
2 103 9.5 18 18-C(O)CH3 Neat
3 22 2 12 0-C(O)CH3 Neat
4 396 4 18 18 -H cyclic
diorgano
polysiloxae
22 2 12 0-C(O)CH3
SURFACTANT 6 = A nonionic silicone surfactant of
trimethylsilyl endcapped polysilicate prepared according to
the method described by Keil in united States Patent No.
3,784,479. A mixture of 12 parts of RESIN I, 22 parts of a
polypropyleneoxide condensate with glycerol having a molecular
weight of 3,500 to 4,000, and 35 parts of xylene was reacted
at 135-140C for 4 hours with 0.17 parts of stannous octoate.
About 0.1 parts of phosphoric acid was added and the product
was stripped of solvent, cooled and then blended with 31 parts
of a polypropylene glycol having a molecular weight of about
2,000, whereupon remaining volatiles were flashed off at 40 mm
Hg at 140C.
REACTION PRODUCT 1 = A reaction product was prepared
according to the method of John et al. as described in EP 0
217 501, by mixing 64.3 parts of POLYORGANOSILOXANE A and 3.43
parts of RESIN I under nitrogen and then stripping at 180C at
80 millibar pressure for 2 hours. The mixture was cooled to
80C and 32 parts of POLYORGANOSILOXANE B and 0.16 parts of
CATALYST I were added with stirring. The mixture was
maintained at 80C under vacuum (80 millibar) for about 5
hours. 0.009 parts of glacial acetic acid and 0.11 parts of
water were added with stirring. 5.27 parts of FINELY DIVIDED
wo 95/~38s 2 1 6 7 3 7 4 PCT~S94/07068
,~0
FILLER I were added with stirring and the product was allowed
to cool.
REACTION PRODUCT 2 = A reaction product was prepared according
to the method of Aizawa United States Patent No. 4,639,489
cited supra. This antifoam contained 60 parts of
POLYORGANOSILOXANE A; 29 parts of POLYOFJANOSILOXANE Bi 2.9
parts of ethyl polysilicate ("silicate 45" of Tama Kagaku
Kogyo Co., Ltd., Japan); 4.8 parts of a potassium silanolate
catalyst; 2.9 parts of Aerogel #200 Silica (Nippon Aerogel
Co., Japan) having a surface area of 200 m2/g; and 4.8 parts
of hydroxy-terminated polydimethylsiloxane having a viscosity
of 40 cS. In addition to the above ingredients, this
formulation also included 0.3 parts of ethanol as part of the
catalyst, 0.1 part of water adsorbed on the silica and 0.1
part of L-540 (from Union Carbide, Danbury, CT) was added.
After the reaction was complete the reaction was stopped by
the addition of carbon dioxide.
REACTION PRODUCT 3 = A reaction product produced by the exact
method described above for REACTION PRODUCT 1 but using 10.66
parts of FINELY DIVIDED FILLER I.
REACTION PRODUCT 4= A reaction product produced by the exact
method described above for REACTION PRODUCT 2 but with the
addition of 10.5 parts of FINELY DIVIDED FILLER II for every
100 parts of silicone reaction product and was added with
mixing just prior the final cooling of the reaction product.
CONCENTRATED LIQUID DETERGENT 1 = a concentrated liquid
detergent according to TABLE 1.
Test Method 1: Each sample was contained in a plastic bottle
which was then subjected to a thermal gradient produced when
they were placed on a warm metal surface, such as the top of a
thermostatic oven or a warm water bath. The metal surface was
maintained at approximately 55C which warmed the bottom of
the sample. Air was free to circulate which cooled the top of
the samples creating a thermal gradient from bottom to top in
the sample. This gradient promoted circulation within the
sample and was found to quickly promote antifoam aggregation.
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
~/
Tes~ Method 2: Each sample was contained in a plastic bottle
and the bottles were placed in a oven thermostatically
controlled to 49C.
EXAMPLE 1
A demonstration of the utility of th- present invention
was conducted in this example. To 447.45 parts of REACTION
PRODUCT 1 was added 52.55 parts of NONREINFORCING FILLER I.
The quartz was first blended in by hand and then mixed under
high shear supplied using a Greerco mixer-homogenizer (model
IL 1989) for 1/2 hour, cooled to room temperature, and
homogenized for a second 1/2 hour. The quartz must be fully
blended into the silicone and was preferably given additional
time to become fully wetted by the silicone antifoam.
Typically our mixtures containing quartz showed optimum
performance when quartz was in contact with the fluid for more
than one day at room temperature.
A non-aqueous emulsion was prepared by adding 600 parts
of the above modified antifoam compound to a combination of
150 parts of SURFACTANT 1 with 810 parts of CONTINUOUS PHASE
I. Stirring was supplied from a Lightin'R LabMaster IITM.
mixer fitted with two airplane style stirring blades operating
at 500 RPM. After about 5 hours, stirring was ceased and a
particle size measurement was performed showing a mean volume
average particle size of 60 microns. This mixture is
designated herein as ANTIFOAM EMULSION A.
A dramatic demonstration of the present invention was
made in the following manner. A 1% mixture of Antifoam
Emulsion A was made in CONCENTRATED LIQUID DETERGENT 1 by
thoroughly dispersing the emulsion into the CONCENTRATED
LIQUID DETERGENT with hand stirring and designated SAMPLE 1.
SAMPLE 2 was made in a similar manner but 0.1 wt.% of
STABILIZING AID I was dispersed into the CONCENTRATED LIQUID
DETERGENT prior the addition of the antifoam emulsion. Both
samples were placed into identical 2 oz. glass vials and were
tested according to Method 1. Sample 1 was observed to have a
medium level of flocculation after approximately 3 hours.
Sample 2 was continuously monitored and only began to show
flocculation obvious to the eye after 9 days.
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
EXAMPLE 2
An illustration of the effect of the stabilizing aid in
the compositions of the present invention was conducted in the
following manner. A series of premixes were made with the
silicas listed below. The premixes were pr~pared at 5.0 wt% by
adding 10 parts of silica to 190 parts of CONTINUOUS PHASE I
by sifting the dry silica powder into the liquid with
stirring. The mixture was stirred for approximately 15
minutes at 400 RPM. All the powder was wetted and thoroughly
mixed to produce a transparent thick liquid. The types of
silica employed in this example are listed in Table II below.
In Table II hereinbelow, PDMS denotes Polydimethylsiloxane,
and HDMZ denotes Hexamethyldisila~ane.
TABLE II
TREATMENT BOUND SPECIFIC
SILICASURFACE AREA TYPE* CARBON LOADING
(m /g) (Wt.%) (Mg C/m )
8 380 NONE - 0
170 (CH3)2Cl2si 1 59
1 120 (CH3)2Cl2si 0.85 71
3 110 (CH3)2Cl2S 1 92
2 200 HMDZ > 3.4 > 175
4 90 PDMS 3 343
6 100 PDMS > 4.5 > 471
wo 95/~385 2 1 6 7 3 7 4 PCT~S94/07068
These silicas were further characterized using a methanol
wettability test (Determination of the Methanol Wettability of
Hydrophobic Fumed Silicas by the Multipoint Method, Method
number ACM-125 from Degussa Corporation, Ridgefield Park,
N.J.) in which the silica samples are shak~n into a series of
solutions of increasing methanol content The solution of
water/methanol at which the silica was fully wetted was
determined following centrifugation of the sample for 5
minutes at 2500 RPM with a 5.75 inch radius rotor. Plotting
of the sediment height as a percent of the sediment height at
complete wetting allows for a multipoint approach.
A series of samples were prepared using the silica
premixes. The 5 wt.% silica premix was blended with Antifoam
Emulsion A to provide 0.05 to 0.4 silica to antifoam ratio and
then the mixture was blended in to CONCENTRATED LIQUID
DETERGENT 1 at 2 wt.%. The samples were observed during
Testing Method 1 and were ranked according to their
performance in terms of aggregation stability in Table III
below. The samples were ranked from 1 to 8, with 1 indicating
the best stability versus aggregation. A description of the
appearance of the samples at 190 Hrs. was recorded for each
sample is also listed in Table III below. A sample containing
no stabilizer was prepared by adding an additional amount of
CONTINUOUS PHASE I in place of the silica premix.
TABLE III
METHANOL RANK RANK RANK RANK 190
HOURS
SILICA WETTABILITY 14 HRS 48 HRS 61 HRS 190 HRS
DESCRITION
MeOH vol %
1 40 1 4 1 2 small flocs
uniformly
dispersed
good
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
2 70 1 1 4 4 1 mm flocs
uniformly dis-
persed
3 45 1 1 3 1 very good:
uniform haze
4 70 6 6 6 6 compact 3-5mm
clumps
1 1 1 3 small flocs/
haze good
6 70 5 5 5 5 1-1.5 mm
flocs
8 10 7 7 7 7 10mm floc-
culate
with haze
NO STABILIZER 8 8 8 8 10mm floc-
culated
EXAMPLE 3
An illustration of the ease of dispersibility of the
antifoam agents according to the present invention in a liquid
detergent was demonstrated in the following manner. 400 g of
DEFOAMER REACTION PRODUCT 3 was blended with 100g of
SURFACTANT 1 to prepare Premix 3-1. Premix 3-2 was prepared
by blen~ing 100 g of STABILIZING AID I into 900 g of
CONTINUOUS PHASE I and then mixed on the Greerco
mixer-homogenizer for 1/2 hour. 250 g of Premix 3-1 was added
to 25 g of Premix 3-2 with stirring by a mechanical mixer with
two six-blade turbine agitators fixed on the shaft operating
at 750 RPM for two hours and then 500 RPM for approximately 5
hours. This mixture was shown to have average particle size in
the 20 to 100 micron range and was suitable for easy
dispersion into detergent concentrates.
WO95/03385 2 1 6 7 3 7 4 PCT~S94/07068
EXAMPLE 4
Different methods of mixing the components of the present
invention and different types of continuous phases were
illustrated in this Example. A series of s~mples were prepared
by blending an antifoam premix with a n-;~n-aqueous premix of
the stabilizing particulate. The antifoam premix was prepared
by using moderate speed mechanical stirring for about one hour
to blend REACTION PRODUCT 1 and various surfactants. The
premix containing the stabilizing particulate was prepared by
sifting the silica into the non-aqueous liquid. Mixing speed
was brought up to 1000 RPM for about 20 minutes. The two
premixes were then combined to form the emulsion, even if only
temporarily stable, by mixing the premixes at high speeds for
example at 1,000 RPM for 5 minutes on LightinR LabMaster IITM
. The anti~oam emulsion was then added to CONCENTRATED LIQUID
DETERGENT 1 to provide an antifoam addition level of 0.5 wt.~
by mixing for 5 minutes at 600 RPM. The content of the
premixes and the amount of each component are described in
Table IV below.
TABLE IV
Antifoam Premix Stabilizing Premix
Reaction Stabilizing
Sample Productl Surfactant Aid I Continuous Phase
A 44.4~ 11.1% # 3 2.2% 42.2 % CONTINUOUS
PHASE III
B 57.0 14.3 # 1 2.8 25.7CONTINUOUS
PHASE II
C 57.0 14.3 # 4 2.8 25.7PROPYLENE
GLYCOL
D 64.5 3.2 # 2 1.6 30.7CONTINUOUS
PHASE II
W095/033~ 2 1 6 7 3 7 4 PCT~S94/07068
~6
EXAMPLE 5
This example is presented to demonstrate the utility of
the present invention. A premix was made by mixing 17.5 parts
of STABILIZING AID I into 402.5 parts of CONTINUOUS PHASE I
with moderate mechanical stirring until the suspension was
uniform. To 420 parts of this premix was added 280 parts of
REACTION PRODUCT 4 with moderate stirring. The mixture was
then homogenized using a Greerco mixer-homegenizer (model IL
1989) for about 30 minutes, with a cooling period, followed by
another 30 minutes of homogenization. This emulsion,
designated ANTIFOAM EMULSION B, had an average particle size
of about a 30 microns as estimated by microscopic examination.
Sample A was prepared by mixing 0.1 parts of ANTIFOAM
EMULSION B into 99.9 parts of CONCENTRATED LIQUID DETERGENT 1
with moderate stirring to form a uniform dispersion.
A comparison was made between SAMPLE A and CONCENTRATED
LIQUID DETERGENT 1 alone using a standardized washing machine
test. This test used a top loading U.S. washing machine run
on a normal cycle with warm wash, medium hardness water (about
120 ppm as calcium carbonate), with clean ballast present in
the load, and a standard detergent dosage of 131 grams. The
CONCENTRATED LIQUID DETERGENT 1 developed a foam head about
8.8 cm high after only three minutes of agitation in the wash
cycle and the foam extended above the lip of the agitator drum
and out of the machine after about three and one-half minutes.
Sample A had a controlled foaming condition throughout the
wash cycle, never approached the lip of the agitator drum, and
had a maximum foam height of only 1.33 cm which occurred at
the end of the 12 minute wash cycle.
EXAMPLE 6
This example compares the compositions of the present
invention against compositions previously disclosed in the
art.
An antifoam 6-1 was prepared following the method of
McGee et al. disclosed in European Patent Application No.
wo gs/0338s 2 ~ 6 7 3 7 4 PCT~S94/07068
341,952 and closely followed the method outlined in Example 25
of that disclosure. Thus, 47.5 parts of REACTION PRODUCT 2
was combined with 47.5 parts of silicone surfactant 5 and 5.0
parts of FINELY DIVIDE FILLER II. Sample 1 was prepared by
mixing 0.85 parts of this antifoam into 99.15 parts of
CONCENTRATED LIQUID DETERGENT 1 with moderate stirring.
Antifoam 6-2 was prepared following the method of Starch
disclosed in United States Patent 4,978,471, Example II in
which 1.3 parts of SILICONE SURFACTANT 1, 2.5 parts of
SILICONE SURFACTANT 6, 8.3 parts of a secondary antifoam
compound of trimethylsilyl-ended polydimethylsiloxane having a
viscosity of 12,500 cS at 25C.,8.3 parts of PLURONIC L-101,
and 1.25 parts of TRITON X-100 were blended into 45.0 parts of
P 4000 with mechanical mixing. To this combination was added
33.3 parts of REACTION PRODUCT 2 with mixing until a uniform
dispersion was formed. Sample 2 was prepared by mixing 1.0
parts of this antifoam into 99 parts of CONCENTRATED LIQUID
DETERGENT 1 with moderate mixing.
Antifoam 6-3 was prepared within the spirit of the
disclosure by Starch in United States Patent 9,978,471 but
using a more easily dispersible liquid continuous phase, P
425, a polypropylene glycol with an average molecular weight
of 425 (marketed by Dow Chemical Company, Midland, MI), in
place of P 4000. Antifoam 6-3 was prepared by combining 1.3
parts of SILICONE SURFACTANT 1, 2.3 parts of SILICONE
SURFACTANT 6, 8.3 parts of a secondary antifoam compound of
trimethylsilyl-ended polydimethylsiloxane having a viscosity
of 12,500 cS at 25C., 8.3 parts of PLURONIC L-101, and 1.25
parts of TRITON X-100 in 45.0 parts of P 425 with mechanical
mixing. To this combination was added 33.3 parts of REACTION
PRODUCT 2 with mixing until a uniform dispersion was formed.
Sample 3 was prepared by mixing 1.0 parts of this antifoam
into 99 parts of CONCENTRATED LIQUID DETERGENT 1 with moderate
mixing.
Antifoams 6-4 and 6-5 were prepared following the method of
Hill et al. in European Patent Application No. 499,364, by
adding 0.25 parts of stannous octoate to antifoams 6-2 and
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
6-3, respectively, and allowing the mixture to slowly stir
overnight at room temperature. Samples 4 and 5 were prepared
by adding 1.0 parts of these antifoams to 99 parts of
CONCENTRATED LIQUID DETERGENT 1, respectively with moderate
mixing.
Antifoam 6-6 was prepared by adding 60 parts of REACTION
PRODUCT 2 to a combination of 7.5 parts of SURFACTANT 1 in
82.5 parts of CONTINUOUS PHASE I with moderate mechanical
stirring. Stirring was maintained for 5 hours. 10 parts of
the resulting emulsion was blended with 3 parts of a 10 wt.%
suspension of STABILIZING AID I in CONTINUOUS PHASE I with
moderate or hand stirring. Sample 6 was prepared by adding 1.3
parts of this antifoam to 98.7 parts of CONCENTRATED LIQUID
DETERGENT 1 with moderate mixing. Sample 7 was prepared by
adding 1.0 parts of ANTIFOAM EMULSION B described in EXAMPLE 5
to 99 parts of CONCENTRATED LIQUID DETERGENT 1 with moderate
mixing. Samples 6 and 7 are within the scope of the present
invention. Samples 1 through 7 were prepared on a 1 kg scale
for the sake of the comparison and were divided into two 500
gram samples for testing. They underwent testing according to
TEST METHOD 1 and TEST METHOD 2 for four days with the
observations tabulated in Table V below.
TABLE V
COLLAR 3 AGGREGATION 3 STABILITY
3 3
Sample3 Method 13Method 23 Method 13Method 2 3Method 13Method 2
1 5 mm 5 mm yes yes bad collected
thick thick < lmm 1 to 3mm collar on bottom
2 ----- ----- WAS NOT DISPERSIBLE ----- -----
3 3 mm 2.5 mm no no collec- collected
ted on on side
side
4 ----- ----- WAS NOT DISPERSIBLE ----- -----
2.5 mm 2.0 mm no no some collectedcollec- on side
ted
W095/03385 2 1 6 7 3 7 4 PCT~S94/07068
~9
6 <1 mm <1 mm no no uniform- uniformly
ly dis- dispersed
persed
7 <1 mm <1.5 mm no no uniform- uniformly
ly dis- dispersed
persed
It should be apparent from the foregoing that many
other variations and modifications may be made in the
compounds, compositions and methods described herein without
departing substantially from the essential features and
concepts of the present invention. Accordingly it should be
clearly understood that the forms of the invention described
herein are exemplary only and are not intended as limitations
on the scope of the present invention as defined in the
appended claims.
