Note: Descriptions are shown in the official language in which they were submitted.
2139~5~
-
UNITED STATES PATENT APPLICATION
for
FOAM CONTROL COMPOSITIONS
of which the following is a specification.
BACKGROUND OF THE INVENTION
The present invention relates to a foam control
composition and to its use in foaming systems. More particularly,
this invention relates to a foam control composition comprising a
0 silicone antifoam agent and a cross-linked organopolysiloxane
polymer having at least one polyoxyalkylene group. The
compositions of this invention exhibit excellent initial antifoam
effect and dispersion stability.
A defoamer or antifoam agent is a material which, when
added in low concentration to a foaming liquid controls the foam
problem. Such materials, in addition, remove unsightly and
troublesome surface foam and improve the filtration, watering,
washing, and drainage of various types of suspensions, mixtures,
and slurries. Defoamers have found application traditionally in
'0 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, detergents, cooling towers, and in chemical processes
~5 of varied description such as municipal and industrial primary
and secondary waste water treatment.
It is essential for a defoamer that it be inert and not
2~3~7
capable of reacting with the product or system in which it is
used, and that it have no adverse effect on the product or
system. A silicone antifoam agent is favorable, because it is
chemically stable, rarely affects the treatment process, and
exhibits a relatively high antifoam effect even in small amounts.
The use of various silicone containing compositions as
antifoams or defoamers is known. In this regard, it is well
established that this art is highly unpredictable and slight
modifications can greatly alter the performance of such
0 compositions. Most of the compositions contain silicone fluid
(usually dimethylpolysiloxane), often in combination with small
amount of silica filler. Many silicone foam control agents are
known to suppress foam.
For example, Sullivan, in U.S. Patent No. 3,383,327,
discloses an antifoam agent prepared from a polydiorganosiloxane
fluid, silica, and a hydroxylated polydimethylsiloxane. Rauner,
in U.S. Patent No. 3,455,839, discloses an aqueous defoaming
composition consisting essentially of a polydimethylsiloxane
fluid, a resin composed of (CH3)3SiOl/2 units and SiO2 units and
'0 a silica aerogel.
Raleigh et al., in U.S. Patent No. 4,012,334, disclose
an antifoam composition comprising a dimethylpolysiloxane and a
precipitated silica reacted with hexamethyldisilazane and a
process for the preparation and use thereof. Edward, in U.S.
'5 Patent No. 4,145,308, discloses roam suppressant compositions,
useful in both aqueous and hydrocarbon liquids, consisting
_ 2~3~j7
essentially of a polydimethylsiloxane, a silicone resin comprised
of R3SiOl/2 units and SiO2 units wherein R is a monovalent
hydrocarbon radical, and fumed or precipitated silica.
Maloney et al., in U.S. Patent No. 4,443,357, disclose
a foam controlling composition consisting essentially of an
organopolysiloxane having at least one terminal alkoxy or hydroxy
group, an organic silicone compound having the general formula
R2SiZ2 wherein R is a monovalent hydrocarbon group and Z is a
hydrolyzable group containing nitrogen, and silica. Pape et al.,
0 in U.S. Patent No. 4,486,336, disclose foam suppressant
compositions consisting essentially of a low viscosity
polydimethylsiloxane, a high viscosity polydimethylsiloxane, a
silicone resin comprising (CH3)3SiOl/2 units and SiO2 units, and
silica.
Aizawa et al., in U.S. Patent Nos. 4,639,489 and
4,749,740 teach a method for producing a silicone defoamer
composition wherein a complex mixture of polyorganosiloxanes,
filler, a resinous siloxane, and a catalyst, to promote the
reaction of the other components, are heated together at 50C to
~0 300C.
Hydrophobed silica/polydimethylsiloxane antifoams are
also reviewed in DEFOAMING: Theory and Industrial Applications;
Garrett, P.R., Ed.; Surfactant Science Series 45; Marcel Dekker:
New York, 1993, especially pages 246-249.
'5 Additionally, these silicone antifoam agents may
include various surfactants and dispersing agents in order in
- ~7
impart improved foam control or stability properties to the
compositions. Thus, for example, Rosen, in U.S. 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 dispersability in water without the need for
emulsification.
Keil, in U.S. Patent No. 3,984,347, discloses a
0 composition for controlling foam which comprises (1) a base oil
of polyoxypropylene polymers, polyoxypropylene-polyoxyethylene
copolymers or siloxane glycol copolymers, (2) an antifoam agent
comprising a liquid polydimethylsiloxane, silica, and optionally
a siloxane resin and (3) a siloxane copolymer dispersing agent.
This composition enables the introduction of a diluted antifoam
agent without having to make a water based emulsion.
McGee et al. in European Patent Application No. 341,952
disclose a foam control composition comprising (1) a silicone
defoamer reaction product and (II) a silicone glycol copolymer,
~0 is disclosed as being particularly effective in defoaming highly
acidic or highly basic aqueous systems. However, when a foam
control composition comprising a silicone antifoam agent and a
silicone glycol copolymer is employed it is added in the form of
a liquid or after dilution with water to a foamable liquid thus
~5 requiring higher levels of the silicone copolymer.
2139~7
SUMMARY OF mHE INVENTION
The present invention reiates to a foam control
composition comprising a silicone antifoam agent and a cross- -
linked organopolysiloxane polymer having at least one
polyoxyalkylene group.
It is an object of this invention to provide foam
control compositions which exhibit excellent initial antifoam
effect and superior dispersion stability.
It is also an object of this invention to provide
foam control compositions which exhibit persistent antifoam
effect.
An additional object of this invention is to provide
foam control compositions which provide excellent dispersion
stability in both diluents and in concentrated surfactant
~5 solutions.
These and other features, objects and advantages of
the present invention will be apparent upon consideration of the
following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and the objects of the invention will be seen
by reference to the detailed description of the invention taken
in connection with the accompanying drawing, in which: FIG 1 is
an elevational view of the device employed for testing the foam
~5 control compositions of the present invention.
' ~.~90S7
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a foam control
composition comprising: (I) a silicone antifoam agent and (II) a
cross-linked organopolysiloxane polymer having at least one
polyoxyalkylene group.
The compounds or compositions employed as the silicone
antifoam agent herein can be alkylated polysiloxane compounds of
several types, and can be used alone, or in combination with
various solid materials such as silica aerogels, xerogels, or
0 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 hydrocarbon groups of various types. In
general terms, the silicone antifoam agent can be siloxanes
having the unit formula:
R
-(Si)x- (1)
'O Rl
wherein x has a value ranging from about 20 to about 2,000, and R
and Rl are independently selected from the group consisting of
alkyl and aryl groups. Preferred alkyl groups include methyl,
~5 ethyl, propyl, and butyl, and preferred aryl groups include
phenyl. Polydimethylsiloxanes (where R and Rl are both methyl)
having a molecular weight within the range of from about 2,000 to
about 200,000, or higher, are all useful as antifoam agents in
the present invention. Such silicone compounds are commercially
Z1390~;'7
available from Dow Corning Corporation under the trade name Dow
Corning 200(R) Fluid.
Additionally, other silicone compounds where the side ~
chain groups, R and R1 are independently selected from the group
consisting of alkyl, aryl, or mixtures of alkyl and aryl groups
exhibit useful foam controlling properties. These compounds are
readily prepared by the hydrolysis of the appropriate alkyl, aryl
or mixtures of alkylaryl silicone dichlorides with water in a
manner well known in the art. Specific examples of such silicone
0 antifoam agents useful as (I) include diethyl polysiloxanes,
dipropyl polysiloxanes, dibutyl polysiloxanes, methylethyl
polysiloxanes, and phenylmethyl polysiloxanes. Dimethyl
polysiloxanes are particularly useful herein due to their low
cost and ready availability.
A second type of silicone antifoam agent useful as (I)
comprises (i) silicone and (ii) silica and can be prepared by
a~mi~ing a silicone fluid of the type described hereinabove with
a hydrophobic silica. Any of several known methods may be used
for making a hydrophobic silica which can be empioyed herein in
'0 combination with a silicone fluid as the antifoam agent. For
example, a fumed silica can be reacted with a trialkyl
chlorosilane (i.e. "silanated") to affix hydrophobic
trialkylsilane groups on the surface of the silica. Silicas
having organosilyl groups on the surface thereof are well known
'S and can be prepared in many ways such as by contacting the
surface of a fumed or precipitated silica or silica aerogel with
reactive silanes such as chlorosilanes or alkoxysilanes or with
silanols or siloxanols or by reacting the silica with silanes or
siioxanes. Various grades of silica having a particle size of
several millimicrons to several microns and a specific surface
area of about 500 to 50 m2/g are commercially available and
several hydrophobic silicas having different surface treatments
are also commercially available.
The silicone antifoam agent (I) can also be any of the
silicone antifoam agents known in the art such as those disclosed
0 in U.S. Patent Nos. 3,383,327, 3,455,839, 4,012,334, 4,145,308,
4,443,357, 4,486,336, 4,639,489, 4,749,740, 4,076,648, and
3,984,347 incorporated herein by reference to teach silicone
antifoam agents which are suitable, and those skilled in the art
are also directed to European Patent Application Nos. 341,952 and
217,501 which also disclose silicone antifoam agents suitable as
component (I). In the above cited references which disclose
antifoam agents suitable for use in the present invention, the
silica present in the antifoam compounds/compositions is
hydrophobed in-situ. This list is not intended as a restriction
'0 on the type of silicone antifoam agent which can be employed in
the foam control compositions of this invention but is disclosed
to exemplify the silicone antifoam agents suitable for use in the
compositions of this instant invention.
Thus the silicone antifoam agent (I) can be a reaction
'5 product prepared by react ng at a temperature of 50C to 300C:
(i) 100 parts by weight of at least one polyorganosiloxane
--- Z13~t~57
selected from the group consisting of (A) a polyorganosiloxane
having a viscosity of about 20 to 100,000 mm2/s at 25C and being
expressed by the general formula R2aSio(4_a~/2 in which R2 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 mm2/s at 25C expressed by the general formula
R3b(R40)Csi0(4-b-c)/2 in which R3 is a monovalent hydrocarbon or
halogenated hydrocarbon group having 1 to 10 carbon atoms, R4 is
0 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 -oR4 group in each
molecule, at least one such -oR4 group being present at the end
of the molecular chain; ~ii) 0.5 to 20 parts by weight of at
.5 least one resinous silicon compound selected from the group
consisting of (a) an organosilicon compound of the general
formula R5dSiX4_d in which R5 is a monovalent hydrocarbon group
having 1 to 5 carbon atoms, X is a hydrolyzable group and d has
an average value of one or less, (b) a partially hydrolyzed
'0 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)3SiOl/2 units to SiO4/2 units is 0.4:1 to 1.2:1,
and (d) a condensate of said compound (c) with said compound (a)
or (b); (iii) up to 30 parts by weight of a finely divided
filler; and (iv) a catalytic amount of a compound for promoting
the reaction of components (i) to (iii). For a more detailed
explanation of the above prepared reaction product one skilled in
the art is directed to U.S. Patent Nos. 4,639,489 and 4,749,740.
The silicone antifoam agent (I) can also be a
composition comprising the reaction product prepared as described
hereinabove and from about 20 to 200 parts by weight for each 100
parts by weight of said reaction product (i) of a silicone-glycol
copolymer having its formula selected from
QR62SiO(R6SiO)j(R62SiO)kSiR62Q or (2a)
0 G
QR62SiO(R6SiO)~SiR~2Q (2b)
G
wherein R6 is a monovalent hydrocarbon or halogenated hydrocarbon
group, Q is R6 or G, j has a value of 1 to 150, k has a value of
1 to 400 and G is a polyoxyalkylene group having its formula
selected from the group consisting of
0 R7~OCH2CH2)m(OCH2CH)nOZ' (3a)
CH3
R7(OCH2CH2)mOZ~ and (3b)
R (OCH2CH)nOZ~ (3c)
CH3
,0 wherein R7 is a divalent hydrocarbon group having 1 to 20 carbon
atoms, m has an average value of about 1 to 50, n has an average
value of 1 to about 50 and Z is selected from the group
consisting of hydrogen, an alkyl radical having 1 to 6 carbon
atoms and an acyl group having 2 to 6 carbon atoms, said silicone
glycol being dispersible in water.
9057
-
~onovalent hydrocarbon groups suitable as R6 include
alkyl radicals, such as methyl, ethyl, propyl, butyl, hexyl,
octyl, and decyl; cycloaliphatic groups, such as cyclohexyl; aryl
groups such as phenyl, tolyl, and xylyl; arylalkyl groups such as
benzyl and phenylethyl. Highly preferred monovalent hydrocarbon
groups are methyl and phenyl. Monovalent halogenated hydrocarbon
groups include any monovalent hydrocarbon radical noted above and
has at least one of its hydrogen atoms replaced with a halogen,
such as fluorine, chlorine, or bromine. The group R7 hereinabove
0 is a divalent hydrocarbon group having from 1 to 20 carbon atoms
which is exemplified by groups such as alkylene radicals
including methylene, ethylene, propylene, butylene, phenylene,
trimethylene, 2-methyltrimethylene, pentamethylene,
hexamethylene, 3-ethyl-hexamethylene, octamethylene,
-CH2(CH3)CH-, -CH2CH(CH3)CH2-, and (CH2)l8 ' Y Y
radicals such as cyclohexylene, arylene radicals such as
phenylene, combinations of divalent Aydrocarbon radicals such as
benzylene (-C6H4CH2-), hydroxylated hydrocarbon residues,
chloroethylene, fluoroethylene, -CH2CH2CH2OCH2-,
.0 -CH2cH2ocH2cH2-~ -CH2CH2OCH(CH3)CH2-, and -CH2OCH2CH2OCH2CH2-.
A more detailed description of the above composition can be found
in European Patent Application No. 341,952. It is preferred that
both Q and R6 of component (II) are methyl radicals and that R7
is the trimethylene group. It is further preferred that j is
'5 between 1 and 10, k is between 0 and 100 and m is between 7 and
12. The silicone glycols are well known ln the art, many of these
- 213~7
being available commercially, and further description thereof is
considered unnecessary.
Component (II) of the foam control compositions of this
invention is a cross-linked organopolysiloxane polymer having at
least one polyoxyalkylene group. This class of compounds have
been generally described by Bahr et.al. in U.S. Patent Nos.
4,853,474 and 5,136,068, incorporated herein by reference to
teach cross-linked organopolysiloxane polymers suitable as (II).
Compounds suitable as (II) include organopolysiloxane-
0 polyoxyalkylene polymer molecules which are intentionally cross-
linked through a cross-linking agent joined thereto by
nonhydrolyzable bonds and being free of internal hydrolyzable
bonds.
Component (II) may be obtained by a method comprising
preparing a cross-linked organopolysiloxane polymer and combining
a polyoxyalkylene group therewith or by a method comprising
preparing a linear polyorganosiloxane having a polyoxyalkylene
group combined therewith and cross-linking the same.
The cross-linking in this system can be attained
0 through a variety of mechanisms. Those skilled in the art will
readily recognize the systems wherein the required components are
mutually compatible to carry out the method of preparing
component (II). By way of illustration, an extensive bibliography
of siloxane polymer chemistry is provided in Siloxane Polymers,
:5 S.J. Clarson and J.A. Semiyen eds., PTR Prentice Hall, Englewood
Cliffs, N.J., (1993).
- 2139~57
-
Not to construed as limiting this invention, it is
preferred that the cross-linking bonds and the bonds to the
organopolysiloxane-polyoxyaikylene molecules are not
hydrolyzable, and that the cross-linking bridge contains no
hydrolyzable bonds. It is recognized that similar emulsifiers
wherein the polyoxyalkylene units are attached to the
organopolysiloxane units via SiOC bonds are useful in
applications not requiring extended stability under conditions
where hydrolysis may occur. It is further recognized that such
0 emulsifiers containing cross-links formed by SiOC bonds offer
benefits of improved emulsion stability and consistency in such
applications not requiring extended stability under conditions
where hydrolysis may occur.
Preferably, the cross-linked siloxane polymer (II~ is
obtained by the addition reaction between the following
components: (i) an organopolysiloxane having an Si-H group at
each of its terminals and an organopolysiloxane having at least
two allyl groups in the side chains of each molecules thereof, or
(ii) more preferably, an organopolysiloxane having at least two
'O Si-H groups in the side chains of each molecule thereof, and a
polyorganopolysiloxane having each of its terminals blocked with
an allyl group or a silanol group.
The preferred cross-linking radical is a vinyl
terminated organosiloxane used in combination with an Si-H
containing backbone. This organosiloxane bridge should not
contain any reactive sites for the polyoxyalkylene moieties. An
2~39~ ;7
organosiloxane bridge cooperates with the siloxane backbones
which it bridges to create a siloxane network at the interface of
water and the silicone antifoam agent. This network is thought to
be important in effecting the stabilizing properties and
characteristics of the present invention. The siloxane bridge
works with other types of antifoams. Other bridge types may be
more suitable for non-silicone antifoams (e.g. an alkane bridge
for mineral oil based antifoams).
The cross-linked organopolysiloxane polymer to be used
0 as (II) should be one that satisfies the following conditions:
~1) it has a three-dimensional crosslinked structure, (2) it has
at least one polyoxyalkylene group, and (3) it has fluidity (i.e.
it is "free flowing"). The term " hree-dimensional cross-linked
structure" used herein denotes a structure in which at least two
organopolysiloxane molecules are bonded together through at least
one bridge.
The exact number of organopolysiloxane-polyoxyalkylene
polymer molecules which will be bridged together will vary within
each compound. One limitation on such cross-linking is that the
'0 overall molecular weight must not become so great as to cause the
material to gel. The extent of cross-linking must thus also be
regulated relative to the molecular weight of each individual
polymer molecule being cross-linked since the overall molecular
weight must also be maintained sufficiently low to avoid gelling.
'5 In controlling the cross-linking reaction there is also the
possibility that some un-cross linked material will be present.
'4
Q~
In the present invention, it is preferred that
component (II) is a compound having a viscosity of 100 to 100,000
mm2/s at 25C and having the unit formula: -
- (R82SiO)e - (R8SiO)f - (R8R9SiO)g -
A (4)
- (R82SiO)h - (R8SiO)i - (R8R9Sio)p -
wherein R8 is a monovalent hydrocarbon group, A is a group having
its formula selected from (CH2)q-(R102SiO)rSi(CH2)S or
O(R102SiO)r-Sio wherein R10 denotes a monovalent hydrocarbon
group, q has a value of 2 to 10, r has a value of 1 to 5000, s
has a value of 2 to 10, R9 denotes a group having its formula
selected from the group consisting of:
ICH3 CH2CH3
2)t (CH2cH2o)u (CH2CHO)v - (CH2CHO)w - R11 (5a)
(EO) (P~ (BO)
'5 CH3
2)t (CH2CH20)U - (CH2CHO)v - R11, (5b)
(EO) (PO)
iCH2CH3
-(CH2)t ~ - (CH2cH2o)u ~ (CH2CHO)w R , (Sc)
(EO) (BO)
CH3 CH2CH3
~0 -(CH2)t ~ O - (CH2CHO)v - (CH2cHo)w R , (5d)
(PO) (BO)
"_ 213~7
(CH2~t ~ - (CH2CH20)u - R11, (5e)
CH3
-(CH2)t ~ - (CH2cHo)v ~ R , and
O (po)
CH2CH3
(CH2)t 0 - (CH2CH0)w - R11, (5 )
(BO)
wherein R11 is selected from a hydrogen atom, an alkyl group, an
0 aryl group, or an acyl group, t has a value of 0 to 6, u has a
value of from greater than zero to 150, v has a value of from
greater than zero to 150, and w has a value of from greater than
zero to 150, e has a value of 1 to 1000, f has a value of from
greater than zero to 30, g has a value of 1 to 1000, h has a
value of 1 to 1000, i has a value of from greater than zero to
30, p has a value of 1 to iO00. In the formula hereinabove EO,
P0, and B0 denote ethylene oxide, propylene oxide, and butylene
oxide groups, respectively. The groups R8 and R10 can be the same
or different as desired and are preferably alkyl groups or aryl
groups and it is highly preferred that they are both methyl.
In the formulae hereinabove, it is preferred that e has
a value of 1 to 500 and it is highly preferred that e has a value
of 1 to 250, it is preferred that f has a value of from greater
than zero to 20 and it is highly preferred that f has a value of
~5 from 1 to 15, it is preferred that g has a value of 1 to 100 and
16
~ 2~057
it is highly preferred that g has a value of 1 to 50, it is
preferred that h has a value of 1 to 500 and it is highly
preferred that h has a value of 1 to 250, it is preferred that i-
has a value of from greater than zero to 20 and it is highly
preferred that i has a value of from greater than 1 to 15, it is
preferred that p has a value of 1 to 100 and it is highly
preferred that p has a value of 1 to 50, it is preferred that q
has a value of 2 to 6, it is preferred that r has a value of 1 to
2500 and it is highly preferred that r has a value of 20 to 1000,
0 it is preferred that s has a value of 2 to 6, it is preferred
that t has a value of 0 to 3, it is preferred that u has a value
of from 1 to 100 and it is highly preferred that u has a value of
5 to 50, it is preferred that v has a value of from 1 to 100 and
it is highly preferred that v has a value of 5 to 50, it is
preferred that w has a value of from 1 to 100 and it is highly
preferred that w has a value of 1 to 50. It is preferred that the
cross-linked organopolysiloxane polymer of component (II) is
triorganosiloxy endblocked at each terminal of the polymer, and
it is highly preferred that the polymer is trimethylsiloxy
:0 endblocked at each terminal of the cross-linked polymer.
A specific example of the method for producing the
crosslinked organopolysiloxane polymers will now be described.
Preparation of a crosslinked organopolysiloxane polymer was done
through the following steps: (I) a charging step in which a
'5 linear polysiloxane having hydrogen atoms in its side chains, a
polysiloxane having vinyl groups and a catalyst for promoting the
2~3g~7
reaction, particularly platinum catalysts such as an isopropanol
solution of H2PtC166H2O wlth a 2% methanol solution of sodium
acetate are put in a reactor, (II) an agitation/heating step in-
which agitation is conducted, or example, at 40C for 30
minutes, (III) an input step in which a polyoxyalkylene and a
solvent (isopropanol) are put in the reactor, (IV) a reflux step
in which the isopropanol is refluxed, for example, at 80C for
1.5 to 2 hours while monitoring the reaction rate of Si-H, (V) a
stripping step in which the isopropanol is stripped, for example,
0 at 130C under a reduced pressure of 25 mmHg, and (VI) a final
step in which the reduced pressure condition of step (V) is
released and the reaction mixture is cooled to 60C to obtain a
final product.
An example of a linear polysiloxane having hydrogen
5 atoms in its side chains suitable for step (I) is a polysiloxane
having its formula selected from:
Me Me ~e Me
Me - Si - O - (SiO)e-(SiO)f+g-Si - Me or (6a)
Me Me H Me
Me Me Me Me
~ I l l I
Me - Si - - (Si)h-(Si)i -Si - Me (6b)
Me Me H Me
,0 wherein Me hereinafter denotes methyl and e, f, g, h, i, and p
are as defined above. An example of a polysiloxane having vinyl
groups suitable for step (I) is a polysiloxane having the
formula:
i8
9~57
-
Me Me Me
Vi - Si - O - (SiO)r - Si - Vi (7)
Me Me Me
wherein Me denotes methyl, Vi hereinafter denotes vinyl, and r is
as defined above. The reaction of these two compounds in step
(II) results in a cross-linked siloxane polymer having the
0 formula
Me Me Me Me Me
Me - Si - O - (SiO)e - (SiO)f - (SiO)g - Si - Me
Me Me ICH2 H Me
ICH2
Me - Si - Me
'O O
(Me21i)r (8)
Me - Si - Me
ICH2
Me Me CH2 Me Me
Me - Si - O - (SiO)h - (SiO)i - (SiO)p - Si - Me
Me Me Me H Me
Introduction of a polyoxyalkylene group into the
obtained crosslinked organopolysiloxane polymer (steps III-VI) is
accomplished by reacting the crosslinked polymer with a
polyoxyalkylene compound having its formula selected from the
group consisting of
~0 Vi - CH2 - O - (EO)u (PO)v (BO)w (9a)
Vi - CH2 - O - (EO)u - (P)v - H~ (9b)
19
2~39057
-
Vi - CH2 - O - (EO)U - (BO)w H, (9c~
Vi - CH2 - - (PO)V - (BO)w - H, (9d)
Vi - CH2 - O - (EO)u - H~ (9e~
i CH2 O - (BO)W - H, and (9f)
5Vi - CH2 - O - (PO)~ - H, (9g)
wherein Vi, EO, PO, and BO are as denoted hereinabove, and u, v,
and w are as defined above. The resulting compound was a cross-
linked organopolysiloxane polymer having the formula
Me Me Me Me Me
O
Me - Si - O - ~SiO)e - (SiO)f - (SiO)g - Si - Me
Me Me ICH2 iCH2 Me
CH2 ICH2
Me - Si - Me CH2
0 O O - (EO)U - (PO)v ~BO)W H
~Me2SiO)r
Me - Si - Me (10)
CH2
Me MeCH2 Me Me
Me - Si - O - (SiO)h - (SiO)i - (SiO)p - Si - Me
Me Me Me CH2 Me
CH2
I
CH2
o - (EO)U - (PO)v - (BO)w H
wherein Me, EO, PO, BO, e, f, g, h, i, p, and r are as defined
0 hereinabove, u has a value of 0 to 150, v has a value of 0 to
lS0, and w has a value of 0 to 150, with the proviso that the
21390~7
- ~,
value of u+v+w is at least one.
The foam control compositions of the present invention
can be produced by mixing 100 parts by weight of silicone
antifoam agent (I) with 0.1 to 1900 parts by weight of cross-
linked organopolysiloxane polymer (II).
More specifically, the foam control compositions ofthis invention can be produced by a method in which cross-linked
organopolysiloxane polymer (II) is added as is or after dilution
with an appropriate solvent or water to the silicone antifoam
O agent (I) and then a homogeneous dissolution or dispersion is
carried out. Alternatively, the composition can be produced by a
method in which component (II) is added at an appropriate time in
the step of producing the foam control composition. These methods
are not critical and any other appropriate ones may also be
utilized.
The foam control compositions of the present invention
may contain other components on an optional basis insofar as the
object of the present invention is not impaired, for example,
inorganic flllers such as quartz, biocides when water is present,
0 silica including hydrophobically treated silicas, metal hydroxide
micropowders such as aluminum hydroxide micropowder, calcium
hydroxide micropowder, and magnesium hydroxide micropowder, bis
amides such as those disclosed in U.S. Patent No. 5,192,336
incorporated herein by reference to disclose amides suitable for
'5 addition to the foam control compositions of the present
invention, flake-form fillers such as mica,
2~390~7
dimethylpolysiloxanes, epoxy-functional diorganopolysiloxanes,
and amino-functional diorganopolysiloxanes, as well as pigments,
corrosion inhibitors, and dyes.
The foam control compositions of the present invention
is added as it is in the form of a liquid or after dilution with
water or another appropriate solvent to a foamable liquid. The
foamable liquid may be a concentrate or be present at end-use
levels. The compositions of the present invention can be used as
any kind of foam control agents, i.e. as defoaming agents and/or
O antifoam agents. Defoaming agents are generally considered as
foam reducers whereas antifoam agents are generally considered as
foam preventors. The compositions of the present invention find
utility as foam control compositions in various media or foamable
liquids such as inks, coatings, paints, detergents (i.e.
compositions which contain surfactants with or without detergency
builders) such as liquid detergents, heavy duty liquid detergents
and textile scours, black liquor, and pulp and paper manufacture.
Various solvents or diluents are available, such as
nonaqueous liquid continuous phases, which are preferably
'O selected from the group consisting of ethylene glycol, propylene
glycol, polypropylene glycol, polyethylene glycol, copolymers of
ethylene and propylene glycols, condensates of polypropylene
glycol with polyols, condensates of polyethylene glycol with
polyols, condensates of copolymers of ethylene and propylene
'5 glycols with polyols, alcohol alkoxylates, and alkylphenol
alkoxylates. The nonaqueous phase is selected for ease of
, _ 2~39Q~
dispersibility and solubility in the foamable liquid. Poor
solubility in the foamable liquid can lead to poor stability and
poor performance of the foam control composition.
From the tables and examples below, it is apparent that
the foam control compositions of the present invention are
excellent in not only the initial antifoam effect but also the
persistence of the antifoam effect and excellent dispersion
stability in both diluents and in concentrated surfactant
solutions (i.e. no coalescence or aggregation was observed). If
0 the foam control compositions are density matched to the media,
phase stability (i.e. stability against sedimentation or
creaming) is also maintained. All parts and percentages in the
examples are on a weight basis anà all measurements were made at
25C unless indicated to the contrary.
EXAMPLES
The following materials, iisted for ease of reference, were
employed in the preparation of the foam control compositions:
'0 COMPONENT I = SILICONE ANT~FOAM (SA) AGENTS:
SA1 was prepared according to the method of Aizawa U.S.
Patent No. 4,639,489 cited supra by mixing together the following
materials: 378 g of polydimethylsiloxane having its terminals
blocked with trimethylsilyl groups, 180 g of polydimethylsiloxane
'5 having its terminals blocked with hydroxyl groups and 18 g of
ethyl polysilicate with heating and then adding 30 g of silica
-
21~90~7
and 30 g of polydimethylsiloxane having its terminals blocked
with hydroxyl groups to the mixture.
SA2 was a trimethylsilyl endblocked polydimethylsiloxane
having a viscosity of 10,000 mm2/s of 25 C.
SA3 was a mixture of 100 parts by weight of a trimethylsilyl
endblocked polydimethylsiloxane having a viscosity of 500 mm2/s
at 25C and 5 parts by weight of wet-process silica.
SA4 was a blend of 95 parts of a trimethylsilyl endblocked
polydimethylsiloxane having a viscosity of 10,000 mm2/s and 5
0 parts hydrophobic silica.
SA5 was an alkyl-modified silicone oil having a degree of
polymerization ranging from 40 to 50 and having an alkyl group
chain length of 12 carbon atoms.
SA6 was a mixture of paraffin oil and hydrophobic silica.
SA7 was prepared according to the method of John et al. as
described in EP 0 217 501, by mixing together 64.3 part of a
polydimethylsiloxane having its terminals blocked with
trimethylsilyl groups, 3.43 parts of a silicone resin and 32
parts polydimethylsiloxane having i~s terminals blocked with
`0 hydroxyl groups with heating and then adding 5.27 parts of silica
and 15.5 parts of quartz to the mixture.
SA8 was a blend of 95 parts of a trimethylsilyl endblocked
polydimethylsiloxane having a viscosity of 12,500 mm2/s and 5
parts of SIPERNAT~ D13 which is a hydrophobic silica from Degussa
'5 Corporation (Ridgefield Park, NJ).
SA9 was prepared by mixing 88.8 parts of trimethylsilyl
24
- - 2~3go~7
endblocked polydimethylsiloxane having a viscosity of 12,500
mm2/s, 8.8 parts of silica gel and 2.4 parts of activated
hexamethyldisilazane.
SA10 was prepared by mixing 88.3 parts of trimethylsilyl
endblocked polydimethylsiloxane having a viscosity of 1000 mm2/s,
2.2 parts of a resin and 9.5 parts of precipitated silica.
SA11 was a blend of 95 parts of a trimethylsilyl endblocked
polydimethylsiloxane having a viscosity of 1,000 mm2/s and 5
parts of CAB-O-SIL (TM) TS-720 which is a hydrophobic silica from
.0 Cabot Corporation (Tuscola, IL).
COMPONENT II = Cp~oc-cT-INKED ORGANOPOLYSILOXANE POLYMERS (CP):
The starting materials used for producing the cross-
linked organopolysiloxane polymers having at least one
polyoxyalkylene group to be used in each of the following
examples are as follows:
Component (A1): was a linear polysiloxane having the
formula:
Me Me Me ~e
~ n
.v
Me - Si - O - (SiO)e-(SiO)f+g~Si - Me
Me Me H Me
'5 wherein e has a value in the range of 74 to 80, and f+g is in the
range of 5 to 9.
Component tA2): was a linear polysiloxane having the
formula:
2139~7
Me Me Me Me
Me - Si - O - (SiO)e-(SiO)f+g-Si - Me
Me Me H Me
wherein e has a value of about 103 and f+g has a value of about
9.5.
Component (Bl): was a.polysiloxane having the formula
0 Me Me Me
Vi - Si - O - (SiO)r - Si - Vi
Me Me Me
having a molecular weight ranging from 8000 to 15,000.
Component (B2): was a polysiloxane having the same
formula as (B1) hereinabove except that B2 has a molecular weight
in the range of 18,000 to 25,000.
'0 Component (B3): was a polysiloxane having the formula
-(MeViSiO)r- wherein r has a value in the range of 3 to 8.
Component (Cl): was a polyoxyalkylene having the
formula: Vi-CH2-O-(EO)U-(PO)v-H having a molecular weight in the
range of from 2000 to 3000 and the ratio of u:v is 1:1.
'5 Component (C2) was a polyoxyalkylene having the same
chemical formula as Cl except that C2 has a molecular weight of
about 1900.
Component (D): was isopropanol (as a solvent).
Component (E): was a 2% methanol solution of sodium
acetate; and
Component (F): was a 2% isopropanol solution of
~2Ptcl6 6H2o.
2~39Q57
Synthesis of cross-linked polymer CPl was prepared by
adding 64.4 grams (g) of (A1), 35.3 g of (B1), 0.47 g of (F), and
0.75 g of (E) in a reactor and the resulting mixture was agitated
at 40C for 30 minutes. Next, 200.2 g of (C1) and 90 g of (D)
were added to the reactor and the isopropanol was refluxed at
80C for 1.5 to 2 hours while monitoring the reaction rate of the
Si-H. The resulting mixture was then stripped to remove the
isopropanol at 130C under a reduced pressure of 25 mmHg. Next,
the reaction mixture was cooled to 60C to obtain a final
0 product.
The obtained crosslinked polymer CP1 was a compound
represented by Chemical Formula (10) described hereinabove
wherein e and h were 76, f and i were 0.58, g and p were 6.42, u
was 24, and v was 24, w was zero, and having a crosslinked chain
length of 140 to 150, a crosslinking ratio of 8.3 and a viscosity
of 31,400 mPa-s (millipascal-seconds). As will be appreciated by
those skilled in the art, the siloxane backbone and the
polyoxyalkylene materials actually are mixtures and the average
mean sizes are listed hereinabove.
`0 The term "cross-linked chain length" used herein means
the number of siloxane units in component (B), and this
determines the value of r in Chemical Formula (10).
The term "cross-linking ratio" used herein means the
ratio of the hydrogen atoms used for formation of cross-linkage
'5 to all of the hydrogen atoms of each molecule of component (A),
which is expressed by the formula: f~(f + g) x 100% or i/i+p x
27
Z1390~7
100% with respect to Chemical Formula (10) hereinabove.
Four types of crosslinked polymers, CP2 to CP5, were
synthesized in the same manner as the one described above for
cross-linked polymer CPl, except that the amount of components
~Al), (Bl), and (Cl) were varied as specified in the following
Table I. The properties of each of the crosslinked polymers are
also given in Table I. With respect to the items not given in the
table, the same characteristics as those for CPl apply.
- Z1390~7
-
Table I
Crossl;nked polymer CP1 CP2 CP3 CP4 CP5
Component (g) (Al) 64.4 64.9 65.4 65.9 66.5 -
Component (g) (B1) 35.3 30.5 26.9 21.7 16.8
Component (g) (C1) 200.2 204.4 207.7 212.3 216.7
e,h 76 76 76 76 76
f,i 0.58 0.50 0.44 0.35 0.27
g,p 6.42 6.50 6.56 6.65 6.73
Crosslinked 140 - 140 - 140 - 140 - 140 -
0 chain length 150 150 150 150 150
Crosslinking ratio 8.3 7.1 6.3 5.0 3.8
Viscosity (mPa s) 31400 20200 14900 10750 7750
Three other types of cross-linked polymers, CP6 to CP8,
were synthesized in the same manner as that described above for
cross-linked polymer CP1, except that the type of components (A)
and (B) were changed and the amounts of the components were
varied as specified in Table II.
The properties of each of the cross-linked polymers are
'0 also given in Table II. With respect to the items not given in
the Table, the same characteristics as those for CP1 apply.
A comparative siloxane polymer (CSP) was also
synthesized in the same manner as described above, except that no
component (B) was used resulting in a silicone glycol copolymer
5 without a bridge, and the amounts of the other components were
29
_ 2139057
~aried as specified in the following Table II. The properties
thereof are also given in Table II. With respect to the items not
given in the table, the same characteristics as those for CPl
apply.
Table II
Cross linked siloxane CP6 CP7 CP8 CSP
Component (A) Type A1 A1 A2 A1
Amount 62.7 72.2 107.1 65.4
0 Component ~B) Type B2 B3 B1
Amount 33.1 0.5 42.8
Component (C) Type C1 C1 C2 C1
Amount 204.2 227.3 150 221.6
e,h 76 76 103 76
f,i 0.27 0.50 .25
g,p 6.73 6.50 9.25 7.00
Cross linked chain length 420-430 3-5 140- -
150
Cross linking Ratio 3.8 7.1 2.6
Viscosity (mPa s) 15000 7800 14600 3500
.0
DILUENTS:
P15-200 (TM) is a polyglycol copolymer from Dow
Chemical Company (Midland, MI).
--- 2139057
UCON (TM) 50HB260 and UCON (TM) 50HB5100 are polyglycol
copolymers from Union Carbide Chemicals and Plastics Company
(Danbuty, CT).
Pluronic (TM) L101 is a block copolymer of ethylene
oxide and propylene oxide from BASF Corporation (Parsippany, NJ).
Evaluation of antifoam performance:
Two foamable water-base liquids were prepared by
dissolving cellulose and lignin compounds in water in a total
concentration of 0.4% by weight to obtain foamable liquid A, and
0 in a total concentration of 2.0% by weight to obtain foamable
liquid B.
Use was made of a testing device shown in Figure 1. 300
g of the above foamable liquid A was introduced into a graduated
glass cylinder (10) having an inner diameter of 50 mm, vertically
erected in a thermostatic bath (20). This foamable liquid was
circulated through a circulation pipe (30) in the direction of
the arrow indicated in Figure 1 at a temperature adjusted to
70C + 1C and at a flow rate of 2.0 e per min by means of a
disconnected magnetic pump (40), so that the foamable liquid
0 continuously dropped from an outlet (35) of the circulation pipe
(30) toward the surface of the liquid phase L in the glass
cylinder (10) to thereby form a foaming condition in the glass
cylinder (10).
This foaming was continued for 10 minutes, and then the
'5 foam control composition was added by the use of a micropipette
in an amount such that the total amount of the first and second
~_ 21390S7
components was 5 ppm based on the foamable liquid.
After the addition of the foam control composition, and
after the lapse of each given circulation time, the volume of a~
foam layer B (the surface thereof being indicated by the broken
line) formed so as to stably remain on the liquid phase L in the
glass cylinder (10) was measured by a scale on the glass cylinder
(10). The initial antifoam effect and the persistence of the
antifoam effect were evaluated on the basis of the measured
volumes.
0 Example 1
A foam control composition, hereinafter referred to as
"Sample 1", was prepared by slowly mixing together the following
materials:
(1) 15 parts by weight of a first component composed of
silicone antifoam agent SA1;
(2) 15 parts by weight of a second component comprised of
cross-linked polymer CP3; and
(3) 70 parts by weight of water.
In order to test the dispersion stability, the Sample 1
'O was allowed to stand still at 25 C. As a result, it was
confirmed that, even after the lapse of 72 hours, the same stable
dispersion condition as that initially observed was maintained.
A comparative foam control composition, hereinafter
referred to as the Comparative Sample 1, was prepared in the same
'5 manner as that described above, except that 13.65 parts by weight
of CSP and 1.35 parts by weight of component (Bl) were used
32
.-_ 21~057
instead of 15 parts by weight of the second component CP3.
In order to test the dispersion stability, the
Comparative Sample 1 was allowed to stand still at 25 C. After-
i2 hours, the formation of an oily aggregate was observed.
The antifoam performance of Sample 1 and Comparative
Sample 1 were tested in the manner described above using foamable
liquid A. The results are shown in Table III.
Table III
- Sample 1Comp. Sample 1
Recipe of 1st comp. SA1 15 15
Antifoam 2nd type CP3 CSP*
Composition Comp. amount 15 15
(wt%) water 70 70
antifoam 0.0 250 250
performance Time 0.5 35 35
Volume of tmin) 1.0 55 70
Foam 3.0 85 125
(ml) 5.0 125 155
lo.0 190 220
* The second component of Comp. Sample 1 is a non-reacted mixtur~
of CSP and an polyorganosiloxane having vinyl groups.
2~39057
Example 2
Foam control compositions, hereinafter referred to as
Samples 2 to 8, were prepared in the same manner as that of
Example 1, except that the amount of the first component SAl was
changed to 5~ by weight, and that each of the CP1 to CP7 was used
as the second component in an amount of 5% by weight.
A comparative foam control composition, hereinafter referred
to as Comparative Sample 2, was prepared in the same manner as
that of Example 1, except 5% by weight of CSP was used instead as
O the second component, and the amount of the first component, SA1,
was changed to 5% by weight.
The antifoam performance of each of the above Samples 2 to 8
and Comparative Sample 2 was tested in the same manner as that of
Example 1, except that use was made of the foamable liquid B. The
results are shown in the following Table IV.
34
21390~7
* o o o
Q. ~ ~ n o o ~ ~o
ao r~
o o o o
o o o a~
U In
U~
r~ U~
.
~D O OLn
p,, O oa~ ~ ~ O
0 1)
a) ~
o o o.,,
P~ n o o o ~--
0 C~ Ln
cn
U~
~r o o~
Q~ ~ o oC~ ~ ~
C~ o
U~
o o In~n
p~ ~ ~ o oco ~r ,1
0
U~
' a) u~
O O t` ~
o .
~,
_, ~ o ~ CO
Sl, P~ O O t` u~
~ ~ ~ ~ o
0 ,,
~ ~ s~ o n oo ~
C
~ ~ ~ ~ o ~ U~
cn E~ O
3 E~
O C
E~ .
~ ~
I O O
O
O
oP O h ;~ ~
O ~ o ~ 5,
3 -~ ~ ~ a) O
a o o ~ ~ o
~) ~ ~ ~ ~ o
~ - 2~3~0~7
Example 3
Foam control compositions, hereinafter referred to as
Samples 9 to 14, were prepared in the same manner as that of
Example 1, except that SA1 and each of the following silicone
antifoam agents SA 2 to 6 were used as the first component in an
amount of 15% by weight, that CP3 was used as the second
component in an amount of 35% by weight, and that water was used
in an amount of 50% by weight.
The antifoam performance of each of the above Samples 9
0 to 14 was tested in the same manner as that of Sample 1 in
Example 1 using foamable liquid A. The results are shown in the
following Table V.
Table V
Sample Sample Sample Sample Sample Sample
9 10 11 12 13 14
.5 Recipe Type SA1 SA2 SA3 SA4 SA5 SA6
of Amount 15 15 15 15 15 15
Comp. CP3 35 35 35 35 35 35
(wt~) water 50 50 50 50 50 50
Antifoam Time 0 230 230 230 230 230 230
'0 PerformØ5 50 70 40 75 50 50
Foam Vol1.0 25 85 50 80 65 70
(ml) 3.0 75 125 85 110 120 115
(min)
36
21390S7
Example 4
Foam control compositions, hereinafter referred to as
Samples i5 to 18, were prepared in the same manner as that of
Example 1, except that different silicone antifoam agents (SA 8
to 11) were used as the first component in an amount of 15% by
weight, that CP8 was used as the second component in an amount of
35% by weight, and that water was used in an amount of 50% by
weight.
Each of the compositions produced as hereinabove
0 described was diluted in accordance with the following recipe:
0.5 g of the emulsion was added to 49.5 g of de-ionized water; 1
g of the previous dilution was then added to 99 g of a 1 wt %
solution of Triton X-100 in an 8 oz square bottle to make a
foaming composition with a total of 50 ppm of component 1 and 2.
The foaming composition was shaken for 10 seconds by a barrel
wrist action shaker. The time t (seconds) between the
discontinuance of shaking and the drop in foam to 5 mm and the
time T (seconds) between the discontinuance of shaking and the
appearance of the liquid surface were measured. The bottle was
'0 shaken again for 40 seconds and the times were likewise measured.
The test was further continued by increasing the shaking time to
60, 120, and 600 seconds. The results are shown below in Table
VI.
2139(~57
Table VI
Sample 15 Sample 16 Sample 17 Sample 18
Recipe of 1st SA 8 SA ~ SA 10 SA 11
Antifoam Comp. 35 35 35 35
Composit- 2nd CP8 CP8 CP8 CP8
ion Comp. 15 15 15 15
(wt~) Water 50 50 50 50
Shake Time (sec) t T t T t T t T
50 ppm 10 58 ~120 27 32 43>120 58 ~120
0 t = 40 82 >120 42 52 2432 168 >120
Collapse 60 110 >120 53 70 2531 195 >120
T = 120 110 >120 65 110 3036 235 >120
Break 600 87 >120 37 43 4354 220 >120
In order to test the dispersion stability, the samples
were allowed to stand still at 25 C. As a result, it was
confirmed that, even after the lapse of 1 month, the same stable
dispersion condition as that initially observed was maintained
with respect to coalescence and aggregation, both for the foam
:0 control compositions and the first dilutions in de-ionized water.
By comparison, samples made in the same manner as examples 15-18,
except that second component, CP8, was replaced with a silicone
glycol copolymer with the same characteristics as CP8 without the
siloxane bridge, were stable less than 48 hours.
38
'-- 213gO57
~xample 5
Samples 19 through 24 were prepared by adding Component
I, the silicone antifoam agent, to the diluent then adding
Component II, the cross-linked polymer, with mixing. The
individual components and their amounts for each sample is listed
below in Table VII.
Table VII
Sample 19 Sample 20 Sample 21 Sample 22 Sample 23 Sample24
SA 7 SA 7 SA 1 SA 1 SA 1 SA 1
0 40.3 39.9 39.9 34.0 39.9 39.6
CP 3 CP 3 CP 3 CP 3 CP 8 CP 8
4.2 0.2 0.3 1.0 0.2 1.0
P15-200 P15-200Ucon 260 Ucon 5100 L101 L101
55.5 59.9 59.8 65.0 59.9 59.4
In order to test the dispersion stability, the samples
were allowed to stand still at 25 C. As a result, it was
confirmed that, even after the lapse of a month, the same stable
dispersions as that initially observed were maintained.
'0 Sample 23 and 24 were further diluted with water to a
total of 15 wt% of Component I and II. These dilutions were also
stable for greater than 1 week. Sample 22 was diluted several
times with water to make various emulsions which include a total
of 12 wt% water, ~1 wt% water and 71 wt% water. These dilutions
~5 were stable for more than a week.
39
2139057
Example 6
Samples 19 and 20 from above were also diluted to 0.1
wt% of the total sample into a concentrated liquid detergent.
This highly concentrated heavy duty liquid detergent containing
from iO to about 24 wt % water has been described, for example,
by Kennedy in U.S. Patent No. 4,973,416.
The samples were allowed to stand still at 25 C. The
silicone antifoam agent remained dispersed for at least one week.
Sample 19 was further tested in a washing machine test. The
0 general procedure may be found in Hill et al. at Col. 14, line
20-Col. 15, line 3 of U.S. Patent No. 5,262,088. The procedure
was modified to use the 0.1 wt % dilution previously described
above. 131 g of this detergent/antifoam combination was added in
place of the combination described by Hill et al. At 12 minutes
the average foam height was 5.6 cm. Without an antifoam present,
the foam typically comes out of the top of the machine before 4
minutes.
~O
