CA1066163A - Method of making aqueous antifoam compositions - Google Patents
Method of making aqueous antifoam compositionsInfo
- Publication number
- CA1066163A CA1066163A CA254,934A CA254934A CA1066163A CA 1066163 A CA1066163 A CA 1066163A CA 254934 A CA254934 A CA 254934A CA 1066163 A CA1066163 A CA 1066163A
- Authority
- CA
- Canada
- Prior art keywords
- emulsifying agent
- radicals
- silica filler
- precipitated silica
- composition
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D19/00—Degasification of liquids
- B01D19/02—Foam dispersion or prevention
- B01D19/04—Foam dispersion or prevention by addition of chemical substances
- B01D19/0404—Foam dispersion or prevention by addition of chemical substances characterised by the nature of the chemical substance
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K9/00—Use of pretreated ingredients
- C08K9/04—Ingredients treated with organic substances
- C08K9/06—Ingredients treated with organic substances with silicon-containing compounds
Abstract
ABSTRACT OF THE DISCLOSURE
A new and improved method of making aqueous, emulsified antifoam compositions is provided in which a silicone oil, a silazane-treated silica filler and emulsifiers are used.
The technique permits the silicone oil and silica filler to be added to the composition, independently and directly, and thus avoids the need for first making an antifoam compound of these ingredients.
A new and improved method of making aqueous, emulsified antifoam compositions is provided in which a silicone oil, a silazane-treated silica filler and emulsifiers are used.
The technique permits the silicone oil and silica filler to be added to the composition, independently and directly, and thus avoids the need for first making an antifoam compound of these ingredients.
Description
The present invention relates to a new and improved method of making aqueous antifoam emulsions by adding a silazane-treated silica filler to a suspension of a silicone fluid in water containing dissolved emulsifiers, Stable, aqueous, emulsified antifoam compositions can thus be prepared without first having to make an antifoam com-pound of a silicone fluid and a silica filler.
~ d -,. _ 1 - ~ i :.
., r ; ~
¦¦ ~ 8SI-1601 ~1 10 661 6 3 1 Back~round of the Invention. - ~ntifoamin~ com-positions are materials used in the prevention, removal and 3 control of unwanted foam. Foamed 1uids are dispersions of 4 - air or other gas as the discon~inuous phase in a continuous liquid phase. Usually, since air or gas makes up the larger S volume portion of such a foam, the bubbles are separated 7 only by a thin liquid film. Unwanted fluid foams are made 8 up of numerous tiny bubbles of a mechanical or chemical 9 origin which are generated within a liquid and which rise and accumulate at the liquid surace faster than they de-Il cay.
13 The fields in which unwanted foams are encounter-14 ed are very diverse, with problems ranging ~rom unesthetic foams to foams which are hazardous. Foam problems are 16 common in polymerization, paint processing and application, 17 fermentation, su~ar-refining, oil drilling and refining, 18 food preparation, paper manufacture, sewa&e disposal, 19 textile dyeing, adhesive application and conversion of ores refined by flotation. Liquid coolants, hydraulic 21 1uids, lubricants, a~iation fuels and gas absorpti~n 22 fluids may foam with undesirable results under conditions 23 of operation. If no~ properly controlled foam can reduce 24 equipment capacity and increase processing time and expense, as well as cause other disadvantages.
27 ~lthough foam can be controlled by making basic ,., , ' ,. . . , ~066~63 changes in the process itself, or by using mechanical de-foaming equipment, chemical antifoaming compositions have proven to be the most effective and economical. sy adding the chemical antifoam compositions to the system, stabilized films are broken, causing the foam bubbles to decay, and thus substantially or completely defoaming the process.
Among the many chemical compositions which are known to be useful for the prevention and destruction of undesirable foams, some of the most effective and versatile anti-foaming agents are silicone fluids. Silicone-based compounds or agents may be used as supplied, as suspensions in solvents or mixed with a portion of a dry ingredient from the foamer formulation.
Emulsions of silicone fluids are also available commercially for use as antifoaming agents. The features which make the use of emulsions desirable include non-flammability, compatibility with aqueous systems, ease of dilution, and effectiveness of these highly dispersed foams of silicones in applications where surface prop-erties are important.
Silicone emulsions are generally made from standard fluids, emulsifying agent, water, and finely divided solids (e.g., silica) which act as carriers for the silicone, increasing the '. /
~ - 3 -:, ,....................................................................... .
Il . 8SI-1601 l 1066163 1 exposed silicone interfacial area a~d~ consequently, the
~ d -,. _ 1 - ~ i :.
., r ; ~
¦¦ ~ 8SI-1601 ~1 10 661 6 3 1 Back~round of the Invention. - ~ntifoamin~ com-positions are materials used in the prevention, removal and 3 control of unwanted foam. Foamed 1uids are dispersions of 4 - air or other gas as the discon~inuous phase in a continuous liquid phase. Usually, since air or gas makes up the larger S volume portion of such a foam, the bubbles are separated 7 only by a thin liquid film. Unwanted fluid foams are made 8 up of numerous tiny bubbles of a mechanical or chemical 9 origin which are generated within a liquid and which rise and accumulate at the liquid surace faster than they de-Il cay.
13 The fields in which unwanted foams are encounter-14 ed are very diverse, with problems ranging ~rom unesthetic foams to foams which are hazardous. Foam problems are 16 common in polymerization, paint processing and application, 17 fermentation, su~ar-refining, oil drilling and refining, 18 food preparation, paper manufacture, sewa&e disposal, 19 textile dyeing, adhesive application and conversion of ores refined by flotation. Liquid coolants, hydraulic 21 1uids, lubricants, a~iation fuels and gas absorpti~n 22 fluids may foam with undesirable results under conditions 23 of operation. If no~ properly controlled foam can reduce 24 equipment capacity and increase processing time and expense, as well as cause other disadvantages.
27 ~lthough foam can be controlled by making basic ,., , ' ,. . . , ~066~63 changes in the process itself, or by using mechanical de-foaming equipment, chemical antifoaming compositions have proven to be the most effective and economical. sy adding the chemical antifoam compositions to the system, stabilized films are broken, causing the foam bubbles to decay, and thus substantially or completely defoaming the process.
Among the many chemical compositions which are known to be useful for the prevention and destruction of undesirable foams, some of the most effective and versatile anti-foaming agents are silicone fluids. Silicone-based compounds or agents may be used as supplied, as suspensions in solvents or mixed with a portion of a dry ingredient from the foamer formulation.
Emulsions of silicone fluids are also available commercially for use as antifoaming agents. The features which make the use of emulsions desirable include non-flammability, compatibility with aqueous systems, ease of dilution, and effectiveness of these highly dispersed foams of silicones in applications where surface prop-erties are important.
Silicone emulsions are generally made from standard fluids, emulsifying agent, water, and finely divided solids (e.g., silica) which act as carriers for the silicone, increasing the '. /
~ - 3 -:, ,....................................................................... .
Il . 8SI-1601 l 1066163 1 exposed silicone interfacial area a~d~ consequently, the
2 e~ectiveness o~ the emulsion as an antifoaming agent. Al~
3 classes of emulsifier8 can be used: anionic5 cationic,
4 and nonionic. ~n most cases, a water-in-oil dispersion is prepared by paSsin& a mixture o~ silicone fluid, 6 emulsifier, some water, and solid dispersant through a 7 high shear blending de~ice such as a colloid mill or homo-8 genizer. The resulting paste is then dispersed in a larger amount o water with vigorous agitation. The final product is a s;l;cone-in-water emulsion, wherein the silicone fluid 11 may constitute up to 70~b of the eotal emulsified composition.
12 Most silicone emulsions, as sold, contain 10-7~10 silicone, 13 but are usually diluted to much lower concentration before 14 use. Commercial silicone emuls~ons are pourable systems of low to moderate viscosity, with good shelf stability 16 and good resistance to phase separation.
18 The dimethyl silicones, in particular, are 19 especially useful in antifoaming agents because of their low surface tension, inertness and insolubility in water.
21 Moreover, they are useful at low concentrations against 22 a wide range of foamers.
24 A recently develop~d class of improved anti-foam agents comprises dimethylpolysiloxane compounds con-26 taining untreated andlor treated fumed silica (e.&., 2? fum~d silica treated with octacyclotetrasiloxane). The . . ~ . .
. ' -4 -. 8SI-1601 ~0 661 6 3 1 general process by which these antifoam compounds are made 2 requires that a mixture o the dimethylpolysiloxane ~luid 3 and the untrea~ed and/or treated fumed silica filler is 4 initially heated to about 150C. in order to disperse the ~iller. The mixture is homogenized under pressure or milled and cooled. It is the~ reheated to about 7 150C. for a considerable time to insure proper iller wet 8 out. Finally, the mixture is again cooled and transerred 9 to a storage container for subsequent use in antifoam com-positions, such as aqueous emulsiied antifoam compositions.
Il 12 It has now been discovered that stable aqueous~
3 emulsified antifbam compositions can be prepared without 14 having to use an antifoam compound. ~nstead, a silicone fluid and a treated precipitated silica filler are éach 16 added directly and separately to ~he antifoam composition.
17 The present method is less tedious and less time consuming 18 than prior art methods and provides a composition o~ better 19 defoaming ability and longer shel stability than aqueous emulsified silicone compositions which employ untreated tl precipitated silica or treated f~med silica.
24 Descri tion of the Invention. - In accordance P
with the present invention, stable~ emulsiied antioam 26 ~ompositions are prepared by a method which comprises:
., , 11 - 5 - I ~lr ~51-1601 1 (i) d~ssolving an emulsifying agent ~n water;
3 ~ii) dispersing a dimethylpolysiloxane ~luid 4 in the solution of the emulsifying agent;
(iii) admixing a silazane-treated precipitated 7 silica filler with the dispersion produced in step ' 8 (ii); and . ,.
(iv) milling the mixture o step (iii) until 11 there is produced a composition which is homogeneous 12 and incapable of separasing into twa layers. -An especial-ly preferred method of practicing 16 the present inNention involves dissolving the emNlsifying 17 a&ent in water at a temperature in the range o~ from about 60C. to about 70~C., dispersing a dimethylpolysiloxane 19 fluid in the solution o emulsifying a&en~ at a temperature about about 60C., admixing a silazane-treated pxecipitated 21 silica filler with this dispersion while maintaining the 22 temperature above about 60~C., and thereafter cooling the 23 mixture to a temperature of about 55C. and milling the 24 cooled mixture.
The treated, precipitated silica filler is pre-par-d by admixin~ the same with a silazane, e~g., hexa-. , ... ' .' ' ' IIF
. 8SI-1601 l 10 661 6 3 1 methydisilazane, at a temperature o~ ~rom about 25C. to 2 about 150~C. for about 1 to 2 hours and~preferablyrat room 3 temperature for about 1 hour. Ammonia is liberated as a 4 by-p~oduct.
S With regard to the materials used in the present 7 method, any o~ the well-known linear dimethylpolysilox~ne 8 fluids haYing a ~iscosity in the range of from about 100 9 to about 70,000 centistokes at 25C. are suitable for the present purposes. For example, dimethylpolysiloxane fluids 11 represented by the following general formula are suitable:
lS R ~ ~ 3 16 ¦¦ R ~ 5~0 t Sl J Sl R
18 . . .
.
21 wherein each R is the same or different and selected ~rom 22 monovalent hydrocarbon and substituted hydrocarbon radicals, 23 such as aliphatic, haloaliphatic and cycloaliphatic, e.g., 24 alkyl, alkenyl, cycloallyl, haloalkyl, including methyl, ethyl, propyl, butyl, chlorobutyl, cyclohexyl, trifluoro-26 propyl, aryl radicals, and halo~enated aryl radicals, such 27 as phenyl7 chlorophenyl; allcenyl radicals such as xylyl, --7 ~
. ' '', . 8SI -16 01 ~0 661 6 3 1 tolyl, and the like; aralkyl radicals, such as phenylethyl, 2 benzyl, and the like; cyanoalkyl, such as cyanoethyl; and 3 n is sufficien~ to provide a viscosity of from about 100 4 to about 70,000 centistokes a~ 25C. Preferably, all the R groups in the above formula are methyl, and i~ is also S preferred that the viscosi~y of the dimethylpolysiloxanes 7 used in the practice of this inNenti~n is from about 100 8 to about 30,000 centistokes at 25C. and most preferably 9 from about 300 to about 1,000 centistokes at 25~C.
.
11 Any of the well-known andlor commercially a~ail-12 able precipitated silica ~illers are useful in the practice 13 of the present invention. These precipitated silica fillers 14 are hi~h surface area materials, the surface area generally being in the ran&e o from about 100 to about 800 m2/g and 16 are &enerally prepared by the depolymerization of high 17 purity sand, which is a crystalline orm of silica, to 18 produce soluble silicate, which in turn is treated to cause 19 repolymerizatiOn and precipitation of extremely par~iculate amorphous filler. The resultant silica is a fine white 21 p~der, the particles of which have fully hydroxylated 22 surfaces, ccvPred by moisture layers. For purposes o 23 this invention the moisture content is ~enerally in the 24 r~n&e of from about 1 to about 15% by weight. Most pre-ferably, the precipita~ed silicas employed herein ha~e 226 a moisture content of from abQut 7 ~o about 10% by weight.
Il I
, ~ 8 --16~66~t;3 Specifically, preferred precipitated silica sillers useful in the practice of the present invention are commercially available from, for example, the Philadelphia Quartz Company, sold under the name of QUSO-F22*; SCM Glidden Durkee Company, sold as Silcron*
G-100; the J. M. Huber Corp., sold as Zeothex* 95; and the W.R. Grace Co., sold as Syloid* 266. All of these precipitated silica fillers are generally identified as hydrated silicon dioxide having a surface area of from about 300 to 400 m2/g, having a moisture content of from about 7 to about 10% by weight.
The emulsifying agent is a compound or compounds selected from among conventional emulsifiers, e.g., oxyethylene sorbitan monostearate (Tween 60*), sorbitan monostearate (Span 60*), polyoxyethylene stearate (Myrj 52S*), and mixtures thereof. Especially preferred is a mixture of sorbitan monostearate (Span 60) and polyoxyethylene stearate (Myrj 52S), commercially available from Atlas Chemical.
of course, other additives which are generally used in antifoam compositions of the present type are also contemplated herein in minor but effective amounts, including bactericides. Sorbic acid is especially preferred as a bactericide, and is preferably added in the present method after the milling step to the milled homogeneous composition.
The amounts of the ingredients employed in the *TM
. . .
/
present process may vary within wide limits. Generally, however, the amount of silazane used, e.g., hexamethyl-disilazane, is from about 8 to 20% by weight, based on the amount of precipitated silica filler employed. Generally, the amount of silazane-treated precipitated silica filler used in the practice of this invention is from about 0.05 to about 1% by weight of the total composition, the amount of dimethylpolysiloxane ranges from about 25 to about 35%
by weight and the amount of emulsifying agent ranges from about 10 to about 20~ by weight, with the balance of the composition comprising water and minor but effective amounts of additives, such as bactericides. An especially preferred amount of bactericide is from about 0.05 to about 2% by weight.
The practice of the present invention is illustrated in the following examples, which are not to be construed as limiting this invention to the embodiments disclosed therein.
EX~PLE 1 A stable, aqueous, emulsified antifoam composition is prepared according to the present invention, as follows:
18 parts by weight of water are charged to a ~066~63 suitable cleaned premix vessel and heated to a temperature of from about 60C. to 70C. While this temperature is maintained, 8.3 parts by weight of emulsifier (Span 60) and 5.7 parts by weight of emulsifier (Myrj 52S) are added with rapid agitation, and the agitation is continued for about 30 minutes after the addition. 31.1 parts by weight of dimethylsilicone oil are slowly added while keeping the temperature above 60C., and the mixture is agitated rapidly for about 30 minutes. Four-tenths part by weight of treated filler are now added, then 36.3 parts by weight of water are added with rapid agitation, and mixing is continued for one hour. After completion of the premix agitation, the batch is cooled to about 53 to 57C., and milled on a Manton-Gaulin colloid mill, at about 3 to 5 mils, into a dilution kettle where moderate agitation is maintained. About 0.2 parts by weight of sorbic acid bactericide are added to the milled dispersion and moderate agitation is continued for about 30 minutes. The emulsifiers are products of Atlas Chemical (ICI America). Equivalents are available, e.g., from Mayer Chemical, Hodag Co., and the like.
The composition prepared by this procedure exhibits the following physical properties:
Property Value Viscosity (cps.) ~ 320 Centrifuge stability T-lcc cream Solids (Weight %) B-.25 cc heavy cream Defoam (mg/ml) 45.2 ~ ~366~63 The defoam test is carried out as follows:
Equipment. - 2 beater kitchen-mixer, 1500 ml.*
beaker; 4 dram vial with dropper, analytical balance, 50 ml.
burette graduated to 0.1 ml., 0.5% solution of sodium lauryl, sulfate.
Note. - The timing sequence for the successive additions of reagent and sample which are described in the procedure are to be duplicated as closely as possible. The elapsed time between successive addition of sodium lauryl-sulfate solution is to be no greater than 30 seconds.
Use in this sequence toluene, acetone and distilled water to rinse the beaker and beaters between tests.
A test temperature of 25C. is recommended. Record the actual test temperature.
Procedures.
1. To a 1500 ml.* beaker which has been arranged for mixing with a mixer add 200 ml. of distilled water.
-* If necessary, a 1/2 gal. ice cream container may be substituted for the 1500 ml. beaker.
~ 8SI-1601 ~066~63 The mixer is to be equipped with two beaters only.
Set the mixer at maximum speed.
2. Add at maximum rate 0.5% Sodium Lauryl Sulfate solution until a foam height which just covers the beaters is formed. (Always refill burette before making additions.) 3. Immediately add enough sample to collapse the foam (usually 1 to 2 drops when pre-conditioning).
4. After the foam level has subsided again add at maximum rate the 0.5% Sodium Lauryl Sulfate as described in Step 2.
12 Most silicone emulsions, as sold, contain 10-7~10 silicone, 13 but are usually diluted to much lower concentration before 14 use. Commercial silicone emuls~ons are pourable systems of low to moderate viscosity, with good shelf stability 16 and good resistance to phase separation.
18 The dimethyl silicones, in particular, are 19 especially useful in antifoaming agents because of their low surface tension, inertness and insolubility in water.
21 Moreover, they are useful at low concentrations against 22 a wide range of foamers.
24 A recently develop~d class of improved anti-foam agents comprises dimethylpolysiloxane compounds con-26 taining untreated andlor treated fumed silica (e.&., 2? fum~d silica treated with octacyclotetrasiloxane). The . . ~ . .
. ' -4 -. 8SI-1601 ~0 661 6 3 1 general process by which these antifoam compounds are made 2 requires that a mixture o the dimethylpolysiloxane ~luid 3 and the untrea~ed and/or treated fumed silica filler is 4 initially heated to about 150C. in order to disperse the ~iller. The mixture is homogenized under pressure or milled and cooled. It is the~ reheated to about 7 150C. for a considerable time to insure proper iller wet 8 out. Finally, the mixture is again cooled and transerred 9 to a storage container for subsequent use in antifoam com-positions, such as aqueous emulsiied antifoam compositions.
Il 12 It has now been discovered that stable aqueous~
3 emulsified antifbam compositions can be prepared without 14 having to use an antifoam compound. ~nstead, a silicone fluid and a treated precipitated silica filler are éach 16 added directly and separately to ~he antifoam composition.
17 The present method is less tedious and less time consuming 18 than prior art methods and provides a composition o~ better 19 defoaming ability and longer shel stability than aqueous emulsified silicone compositions which employ untreated tl precipitated silica or treated f~med silica.
24 Descri tion of the Invention. - In accordance P
with the present invention, stable~ emulsiied antioam 26 ~ompositions are prepared by a method which comprises:
., , 11 - 5 - I ~lr ~51-1601 1 (i) d~ssolving an emulsifying agent ~n water;
3 ~ii) dispersing a dimethylpolysiloxane ~luid 4 in the solution of the emulsifying agent;
(iii) admixing a silazane-treated precipitated 7 silica filler with the dispersion produced in step ' 8 (ii); and . ,.
(iv) milling the mixture o step (iii) until 11 there is produced a composition which is homogeneous 12 and incapable of separasing into twa layers. -An especial-ly preferred method of practicing 16 the present inNention involves dissolving the emNlsifying 17 a&ent in water at a temperature in the range o~ from about 60C. to about 70~C., dispersing a dimethylpolysiloxane 19 fluid in the solution o emulsifying a&en~ at a temperature about about 60C., admixing a silazane-treated pxecipitated 21 silica filler with this dispersion while maintaining the 22 temperature above about 60~C., and thereafter cooling the 23 mixture to a temperature of about 55C. and milling the 24 cooled mixture.
The treated, precipitated silica filler is pre-par-d by admixin~ the same with a silazane, e~g., hexa-. , ... ' .' ' ' IIF
. 8SI-1601 l 10 661 6 3 1 methydisilazane, at a temperature o~ ~rom about 25C. to 2 about 150~C. for about 1 to 2 hours and~preferablyrat room 3 temperature for about 1 hour. Ammonia is liberated as a 4 by-p~oduct.
S With regard to the materials used in the present 7 method, any o~ the well-known linear dimethylpolysilox~ne 8 fluids haYing a ~iscosity in the range of from about 100 9 to about 70,000 centistokes at 25C. are suitable for the present purposes. For example, dimethylpolysiloxane fluids 11 represented by the following general formula are suitable:
lS R ~ ~ 3 16 ¦¦ R ~ 5~0 t Sl J Sl R
18 . . .
.
21 wherein each R is the same or different and selected ~rom 22 monovalent hydrocarbon and substituted hydrocarbon radicals, 23 such as aliphatic, haloaliphatic and cycloaliphatic, e.g., 24 alkyl, alkenyl, cycloallyl, haloalkyl, including methyl, ethyl, propyl, butyl, chlorobutyl, cyclohexyl, trifluoro-26 propyl, aryl radicals, and halo~enated aryl radicals, such 27 as phenyl7 chlorophenyl; allcenyl radicals such as xylyl, --7 ~
. ' '', . 8SI -16 01 ~0 661 6 3 1 tolyl, and the like; aralkyl radicals, such as phenylethyl, 2 benzyl, and the like; cyanoalkyl, such as cyanoethyl; and 3 n is sufficien~ to provide a viscosity of from about 100 4 to about 70,000 centistokes a~ 25C. Preferably, all the R groups in the above formula are methyl, and i~ is also S preferred that the viscosi~y of the dimethylpolysiloxanes 7 used in the practice of this inNenti~n is from about 100 8 to about 30,000 centistokes at 25C. and most preferably 9 from about 300 to about 1,000 centistokes at 25~C.
.
11 Any of the well-known andlor commercially a~ail-12 able precipitated silica ~illers are useful in the practice 13 of the present invention. These precipitated silica fillers 14 are hi~h surface area materials, the surface area generally being in the ran&e o from about 100 to about 800 m2/g and 16 are &enerally prepared by the depolymerization of high 17 purity sand, which is a crystalline orm of silica, to 18 produce soluble silicate, which in turn is treated to cause 19 repolymerizatiOn and precipitation of extremely par~iculate amorphous filler. The resultant silica is a fine white 21 p~der, the particles of which have fully hydroxylated 22 surfaces, ccvPred by moisture layers. For purposes o 23 this invention the moisture content is ~enerally in the 24 r~n&e of from about 1 to about 15% by weight. Most pre-ferably, the precipita~ed silicas employed herein ha~e 226 a moisture content of from abQut 7 ~o about 10% by weight.
Il I
, ~ 8 --16~66~t;3 Specifically, preferred precipitated silica sillers useful in the practice of the present invention are commercially available from, for example, the Philadelphia Quartz Company, sold under the name of QUSO-F22*; SCM Glidden Durkee Company, sold as Silcron*
G-100; the J. M. Huber Corp., sold as Zeothex* 95; and the W.R. Grace Co., sold as Syloid* 266. All of these precipitated silica fillers are generally identified as hydrated silicon dioxide having a surface area of from about 300 to 400 m2/g, having a moisture content of from about 7 to about 10% by weight.
The emulsifying agent is a compound or compounds selected from among conventional emulsifiers, e.g., oxyethylene sorbitan monostearate (Tween 60*), sorbitan monostearate (Span 60*), polyoxyethylene stearate (Myrj 52S*), and mixtures thereof. Especially preferred is a mixture of sorbitan monostearate (Span 60) and polyoxyethylene stearate (Myrj 52S), commercially available from Atlas Chemical.
of course, other additives which are generally used in antifoam compositions of the present type are also contemplated herein in minor but effective amounts, including bactericides. Sorbic acid is especially preferred as a bactericide, and is preferably added in the present method after the milling step to the milled homogeneous composition.
The amounts of the ingredients employed in the *TM
. . .
/
present process may vary within wide limits. Generally, however, the amount of silazane used, e.g., hexamethyl-disilazane, is from about 8 to 20% by weight, based on the amount of precipitated silica filler employed. Generally, the amount of silazane-treated precipitated silica filler used in the practice of this invention is from about 0.05 to about 1% by weight of the total composition, the amount of dimethylpolysiloxane ranges from about 25 to about 35%
by weight and the amount of emulsifying agent ranges from about 10 to about 20~ by weight, with the balance of the composition comprising water and minor but effective amounts of additives, such as bactericides. An especially preferred amount of bactericide is from about 0.05 to about 2% by weight.
The practice of the present invention is illustrated in the following examples, which are not to be construed as limiting this invention to the embodiments disclosed therein.
EX~PLE 1 A stable, aqueous, emulsified antifoam composition is prepared according to the present invention, as follows:
18 parts by weight of water are charged to a ~066~63 suitable cleaned premix vessel and heated to a temperature of from about 60C. to 70C. While this temperature is maintained, 8.3 parts by weight of emulsifier (Span 60) and 5.7 parts by weight of emulsifier (Myrj 52S) are added with rapid agitation, and the agitation is continued for about 30 minutes after the addition. 31.1 parts by weight of dimethylsilicone oil are slowly added while keeping the temperature above 60C., and the mixture is agitated rapidly for about 30 minutes. Four-tenths part by weight of treated filler are now added, then 36.3 parts by weight of water are added with rapid agitation, and mixing is continued for one hour. After completion of the premix agitation, the batch is cooled to about 53 to 57C., and milled on a Manton-Gaulin colloid mill, at about 3 to 5 mils, into a dilution kettle where moderate agitation is maintained. About 0.2 parts by weight of sorbic acid bactericide are added to the milled dispersion and moderate agitation is continued for about 30 minutes. The emulsifiers are products of Atlas Chemical (ICI America). Equivalents are available, e.g., from Mayer Chemical, Hodag Co., and the like.
The composition prepared by this procedure exhibits the following physical properties:
Property Value Viscosity (cps.) ~ 320 Centrifuge stability T-lcc cream Solids (Weight %) B-.25 cc heavy cream Defoam (mg/ml) 45.2 ~ ~366~63 The defoam test is carried out as follows:
Equipment. - 2 beater kitchen-mixer, 1500 ml.*
beaker; 4 dram vial with dropper, analytical balance, 50 ml.
burette graduated to 0.1 ml., 0.5% solution of sodium lauryl, sulfate.
Note. - The timing sequence for the successive additions of reagent and sample which are described in the procedure are to be duplicated as closely as possible. The elapsed time between successive addition of sodium lauryl-sulfate solution is to be no greater than 30 seconds.
Use in this sequence toluene, acetone and distilled water to rinse the beaker and beaters between tests.
A test temperature of 25C. is recommended. Record the actual test temperature.
Procedures.
1. To a 1500 ml.* beaker which has been arranged for mixing with a mixer add 200 ml. of distilled water.
-* If necessary, a 1/2 gal. ice cream container may be substituted for the 1500 ml. beaker.
~ 8SI-1601 ~066~63 The mixer is to be equipped with two beaters only.
Set the mixer at maximum speed.
2. Add at maximum rate 0.5% Sodium Lauryl Sulfate solution until a foam height which just covers the beaters is formed. (Always refill burette before making additions.) 3. Immediately add enough sample to collapse the foam (usually 1 to 2 drops when pre-conditioning).
4. After the foam level has subsided again add at maximum rate the 0.5% Sodium Lauryl Sulfate as described in Step 2.
5. Add 2 drops of sample.
6. After the foam level has subsided shut t'ne mixer off. The time interval between the following two steps should be no longer than 10 minutes.
7. Weigh a weighing bottom containing approximately 10 gms. of sample and a medicine dropper to +0.001 gms. Record the weight as Wl.
8. Turn the mixer to maximum speed. Record the volume of Sodium Lauryl Sulfate reagent in the ~66163 burette. Repeat Step 2 (each time noting the volume of reagent used) and Step 3 until five successive additions of reagent and sample have been made.
9. Weigh the weighing bottle with sample and dropper. Record the weight as W2.
10. Total the volume of each of the five additions of Sodium Lauryl Sulfate addedin Step 8. Record the volume as VT. Divide by 5 to obtain the average volume, VA. Divide the average by 4. Add and substract this result to VA to give the range VL - Vu.
Compare each of the five individual volumes to this range. They must fall within the range or else the test is to be repeated.
Compare each of the five individual volumes to this range. They must fall within the range or else the test is to be repeated.
11. Calculate the ratio, R, of the total weight in mgm. of sample used to the total volume in ml. of Sodium Lauryl Sulfate used.
Wl - W2 VT
Wl - W2 VT
12. Convert milligrams of sample/ml. of Sodium Lauryl Sulfate solution to mg, silicone/ml. as follows:
10~6163 mg. silicone/ml. = R
It is seen from the above detailed description that the present invention provides a beneficial process for the production of antifoam emulsions using dimethyl-polysiloxane oil and a silica filler, instead of a con-ventional antifoam compound. The filler should be a sil-azane, - especially a hexamethyldisilazane-treated pre-cipitated silica. Obviously, modifications can be made without departing from the scope or spirit of the invention.
All such obvious variations are embraced by the full in-tended scope of the appended claims.
10~6163 mg. silicone/ml. = R
It is seen from the above detailed description that the present invention provides a beneficial process for the production of antifoam emulsions using dimethyl-polysiloxane oil and a silica filler, instead of a con-ventional antifoam compound. The filler should be a sil-azane, - especially a hexamethyldisilazane-treated pre-cipitated silica. Obviously, modifications can be made without departing from the scope or spirit of the invention.
All such obvious variations are embraced by the full in-tended scope of the appended claims.
Claims (10)
1. A method of making a stable, emulsified anti-foam composition, which comprises:
(i) dissolving an emulsifying agent in water;
(ii) dispersing a dimethylpolysiloxane fluid in the solution of the emulsifying agent;
(iii) admixing a silazane-treated precipitated silica filler with the dispersion produced in step (ii); and (iv) milling the mixing of step (iii) until there is produced a composition which is homogeneous and incapable of separating into two layers.
(i) dissolving an emulsifying agent in water;
(ii) dispersing a dimethylpolysiloxane fluid in the solution of the emulsifying agent;
(iii) admixing a silazane-treated precipitated silica filler with the dispersion produced in step (ii); and (iv) milling the mixing of step (iii) until there is produced a composition which is homogeneous and incapable of separating into two layers.
2. A method as defined in Claim 1 which further comprises adding a bactericide to the milled homogeneous composition.
3. A method as defined in Claim 2 wherein the bactericide is sorbic acid.
4. A method as defined in Claim 1 wherein the filler is a hexamethyldisilazane-treated precipitated silica filler.
5. A method as defined in Claim 1 wherein the dimethylpolysiloxane fluid has the general formula wherein each R is the same or different and is selected from the group consisting of aliphatic radicals, haloali-phatic radicals, cycloaliphatic radicals, cyanoalkyl radicals, aryl radicals, alkaryl radicals, haloaryl radicals and aralkyl radicals and n is a number sufficient to provide a viscosity from about 100 to about 70,000 centistokes at 25°C.
6. A method as defined in Claim 1 wherein the emulsifying agent consists of a mixture of sorbitan mono-stearate and polyoxyethylene stearate.
7. A method of making a stable, emulsified antifoam composition, which comprises:
(i) dissolving an emulsifying agent in water at a temperature in the range of from about 60°C.
to about 70°C.;
(ii) dispersing a dimethylpolysiloxane fluid in the solution of emulsifying agent at a tem-perature above about 60°C.;
(iii) admixing a hexamethyldisilazane-treated precipitated silica filler with the dispersion of step (ii) while maintaining the temperature above about 60°C., and thereafter cooling the mixture to a temperature of about 55°C.; and (iv) milling the cooled mixture of step (iii) until there is produced a composition which is homogeneous and incapable of separation into two layers.
(i) dissolving an emulsifying agent in water at a temperature in the range of from about 60°C.
to about 70°C.;
(ii) dispersing a dimethylpolysiloxane fluid in the solution of emulsifying agent at a tem-perature above about 60°C.;
(iii) admixing a hexamethyldisilazane-treated precipitated silica filler with the dispersion of step (ii) while maintaining the temperature above about 60°C., and thereafter cooling the mixture to a temperature of about 55°C.; and (iv) milling the cooled mixture of step (iii) until there is produced a composition which is homogeneous and incapable of separation into two layers.
8. A method as defined in Claim 7 wherein the amount of dimethylpolysiloxane ranges from about 25 to about 35%
by weight, the amount of treated, precipitated silica filler ranges from about 0.05 to about 1% by weight, the amount of emulsifying agent ranges from about 10 to about 20% by weight and the balance comprises water.
by weight, the amount of treated, precipitated silica filler ranges from about 0.05 to about 1% by weight, the amount of emulsifying agent ranges from about 10 to about 20% by weight and the balance comprises water.
9. A method of making a stable, emulsified antifoam composition, which comprises:
i) dissolving from about 10 to about 20% by weight of an emulsifying agent in water at a temperature of from about 60°
C. to about 70°C., said emulsifying agent being selected from the group consisting of oxyethylene sorbitan monostearate, polyoxy-ethylene stearate, sorbitan monostearate and mixtures thereof;
ii) dispersing a dimethylpolysiloxane fluid in a solu-tion of said emulsifying agent at a temperature above about 60°C.;
iii) admixing from about 0.05 to about 1% by weight of a silazane-treated precipitated silica filler with the dispersion of step (ii) while maintaining the temperature above about 60°C., and thereafter cooling the mixture to a temperature of about 55°C.; and iv) milling the cooled mixture of step (iii) until there is produced a composition which is homogeneous and incapable of separation into two layers.
i) dissolving from about 10 to about 20% by weight of an emulsifying agent in water at a temperature of from about 60°
C. to about 70°C., said emulsifying agent being selected from the group consisting of oxyethylene sorbitan monostearate, polyoxy-ethylene stearate, sorbitan monostearate and mixtures thereof;
ii) dispersing a dimethylpolysiloxane fluid in a solu-tion of said emulsifying agent at a temperature above about 60°C.;
iii) admixing from about 0.05 to about 1% by weight of a silazane-treated precipitated silica filler with the dispersion of step (ii) while maintaining the temperature above about 60°C., and thereafter cooling the mixture to a temperature of about 55°C.; and iv) milling the cooled mixture of step (iii) until there is produced a composition which is homogeneous and incapable of separation into two layers.
10. A method as defined in claim 9 wherein said silazane-treated precipitated silica filler is a hexamethyl-disilazane-treated precipitated silica filler.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/588,700 US4005044A (en) | 1975-06-20 | 1975-06-20 | Method of making aqueous antifoam compositions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1066163A true CA1066163A (en) | 1979-11-13 |
Family
ID=24354943
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA254,934A Expired CA1066163A (en) | 1975-06-20 | 1976-06-16 | Method of making aqueous antifoam compositions |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4005044A (en) |
| JP (1) | JPS6035163B2 (en) |
| BE (1) | BE848110A (en) |
| CA (1) | CA1066163A (en) |
| DE (1) | DE2626942A1 (en) |
| FR (1) | FR2315972A1 (en) |
| GB (1) | GB1549884A (en) |
Families Citing this family (29)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4075118A (en) * | 1975-10-14 | 1978-02-21 | The Procter & Gamble Company | Liquid detergent compositions containing a self-emulsified silicone suds controlling agent |
| US4136045A (en) * | 1976-10-12 | 1979-01-23 | The Procter & Gamble Company | Detergent compositions containing ethoxylated nonionic surfactants and silicone containing suds suppressing agents |
| US4145308A (en) * | 1977-07-07 | 1979-03-20 | General Electric Company | Anti-foam silicone emulsion, and preparation and use thereof |
| DE3128631A1 (en) * | 1981-07-20 | 1983-02-03 | Henkel Kgaa | "METHOD FOR PRODUCING A FOAMED, SILICONE-CONTAINING DETERGENT" |
| US4584125A (en) * | 1984-08-10 | 1986-04-22 | Sws Silicones Corporation | Antifoam compositions |
| USRE34584E (en) * | 1984-11-09 | 1994-04-12 | The Procter & Gamble Company | Shampoo compositions |
| US4874547A (en) * | 1985-04-02 | 1989-10-17 | Dow Corning Corporation | Bi-modal silicone emulsions, silicone emulsification process and emulsions therefrom |
| CA1260795A (en) * | 1985-04-02 | 1989-09-26 | Dipak Narula | Emulsification process and emulsions therefrom |
| JPH0626643B2 (en) * | 1987-02-25 | 1994-04-13 | 東レ・ダウコーニング・シリコーン株式会社 | Antifoam composition for paper processing |
| US5169560A (en) * | 1990-09-17 | 1992-12-08 | Betz Laboratories, Inc. | Control of foam in hydrocarbon fluids |
| SE9301347A0 (en) * | 1992-04-27 | 1993-10-28 | Nikko Chemical Inst Inc | Anti-foaming composition of emulsion type and anti-foaming method using the same |
| US5643862A (en) * | 1992-06-06 | 1997-07-01 | The Procter & Gamble Company | Stable foam-controlled liquid detergent compositions |
| JP3711561B2 (en) * | 1993-04-05 | 2005-11-02 | 三菱ウェルファーマ株式会社 | Antithrombin-III liquid formulation and stabilization method thereof |
| US5648327A (en) * | 1993-07-22 | 1997-07-15 | The Procter & Gamble Company | Stable liquid detergent compositions comprising a dispersible silicone-based suds suppressor system |
| US6136917A (en) * | 1993-07-22 | 2000-10-24 | Dow Corning Corporation | Stable dispersible silicone compositions |
| US5667669A (en) * | 1996-03-22 | 1997-09-16 | Betzdearborn Inc. | Methods for inhibiting foam |
| US5800738A (en) * | 1996-06-13 | 1998-09-01 | Betzdearborn Inc. | Methods for inhibiting foam in crude oils |
| US6083998A (en) | 1998-04-24 | 2000-07-04 | Betzdearborn Inc. | Defoamer and methods of use thereof |
| US6837778B2 (en) * | 2000-11-24 | 2005-01-04 | Neomax Co., Ltd | Method for cutting rare earth alloy, method for manufacturing rare earth magnet, and wire-saw machine |
| WO2003033207A1 (en) * | 2001-10-17 | 2003-04-24 | Neomax Co., Ltd. | Cutting method using wire saw, wire saw device, and method of manufacturing rare-earth magnet |
| BR0215793B1 (en) * | 2002-06-26 | 2012-11-27 | methods for reducing waste accumulation in a washing unit used in a hydrocarbon cracking process. | |
| US7906012B2 (en) * | 2002-07-16 | 2011-03-15 | Dorf Ketal Chemicals India Pvt. Ltd. | Method for reducing foam in a primary fractionator |
| DE10349082A1 (en) * | 2003-10-22 | 2005-05-25 | Wacker-Chemie Gmbh | Aqueous polymer dispersions |
| DE102004063762A1 (en) * | 2004-12-29 | 2006-07-13 | Wacker Chemie Ag | Reactive silica suspensions |
| EP2601245A1 (en) | 2010-08-05 | 2013-06-12 | Biofilm IP, LLC | Cyclosiloxane-substituted polysiloxane compounds, compositions containing the compounds and methods of use thereof |
| US20150141561A1 (en) * | 2012-06-08 | 2015-05-21 | Dow Corning Toray Co., Ltd. | Carboxy silicone containing composition and process for preparing the composition |
| MX2013014352A (en) | 2013-12-06 | 2015-06-10 | Inst Mexicano Del Petróleo | Formulations of homopolymers based on alkyl acrylates used as antifoaming agents in heavy and super-heavy crude oils. |
| MX2015009234A (en) | 2015-07-17 | 2017-01-16 | Inst Mexicano Del Petróleo | Formulations of copolymers based on alkyl acrylates used as defoamers of heavy and super-heavy crude oils. |
| MX2016004130A (en) | 2016-03-31 | 2017-09-29 | Inst Mexicano Del Petróleo | Formulation of terpolymers based on alkyl acrylates employed as antifoaming of gasified heavy and super-heavy crude oils. |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL100779C (en) * | 1958-02-20 | |||
| CA662734A (en) * | 1959-07-20 | 1963-05-07 | Hercules Powder Company | Defoamer |
| GB1020022A (en) * | 1962-12-21 | 1966-02-16 | Midland Silicones Ltd | Organopolysiloxane antifoam compositions |
| US3666681A (en) * | 1970-03-16 | 1972-05-30 | Dow Corning | Antifoam preparation for aqueous systems |
| US3856701A (en) * | 1971-05-17 | 1974-12-24 | Dow Corning | Antifoam composition |
| JPS5135556B2 (en) * | 1973-06-08 | 1976-10-02 | ||
| US4012334A (en) * | 1974-11-12 | 1977-03-15 | General Electric Company | Antifoam compositions and process for the preparation and use thereof |
-
1975
- 1975-06-20 US US05/588,700 patent/US4005044A/en not_active Expired - Lifetime
-
1976
- 1976-06-09 GB GB23829/76A patent/GB1549884A/en not_active Expired
- 1976-06-16 CA CA254,934A patent/CA1066163A/en not_active Expired
- 1976-06-16 DE DE19762626942 patent/DE2626942A1/en not_active Withdrawn
- 1976-06-18 FR FR7618589A patent/FR2315972A1/en not_active Withdrawn
- 1976-06-21 JP JP51072304A patent/JPS6035163B2/en not_active Expired
- 1976-11-08 BE BE172169A patent/BE848110A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FR2315972A1 (en) | 1977-01-28 |
| GB1549884A (en) | 1979-08-08 |
| DE2626942A1 (en) | 1976-12-30 |
| US4005044A (en) | 1977-01-25 |
| JPS6035163B2 (en) | 1985-08-13 |
| BE848110A (en) | 1977-03-01 |
| JPS522887A (en) | 1977-01-10 |
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