JPH10113552A - Dilution-stable defoaming emulsion concentrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a defoaming agent which can be diluted in a wide range of the concentration by producing a water-in-oil type emulsion by adding polyorgano siloxane having a specified formula, fine powder silica having a specified average particle size, an emulsifying agent having a specified hydrophilicity-hydrophobicity ratio, a specified thickener, and water. SOLUTION: A defoaming agent concentrate forming a water-in-oil type emulsion is produced by adding about 1-99wt.% of polyorgano siloxane having a formula MDx M, about 0.01-50.0wt.% of fine powder silica having about 0.001-1000μm average particle size, about 0.10-50.0wt.% of an emulsifying agent having about 2-20 hydrophilicity-lipophilicity ratio, about 0.001-20.0wt.% of a thickener with molecular weight about 100-100,000,000 Dalton, and slightly more than 0wt.% and not more than 20.0wt.% of water. In the formula MDx M, M=R<1> R<2> R<3> SiO1/2 , D=R<4> R<5> SiO2/2 wherein R<1> -R<5> stand for univalent hydrocarbon groups and x for about 1-10000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antifoam concentrate which forms an oil-in-water emulsion which is a water-in-oil emulsion when concentrated, but continues to function as an antifoaming agent when diluted.

[0002]

BACKGROUND OF THE INVENTION Antifoam compositions are materials that, when added to a foaming liquid, balance or accelerate the rate of foam collapse relative to the rate of foam formation. Usually, such materials are added at low concentrations. Antifoams find use in a wide variety of manufacturing and treatment processes, including paints and latex, painting processes, textile materials, fermentation processes, polymer manufacturing, cleaning compounds, pulp and papermaking, wastewater treatment, and cooling towers. Have been.

It is generally desirable for an antifoaming agent to be inert to the product or system in which it is used, in other words, to have no adverse effect. The components of the antifoam composition generally consist of primary and secondary antifoams, carriers, emulsifiers, and optionally stabilizers. Primary defoamers are typically hydrophobic silicas dispersed in oils such as hydrocarbon waxes, fatty acids, fatty acid esters or fatty acid amides. It is the combination of the two components that produces the defoaming action, since hydrophobic silica by itself has no foam breaking activity. The secondary defoamer is usually a silicone or fatty alcohol or fatty acid ester, which increases the defoaming effect of the primary defoamer. Commonly used carriers include hydrocarbon oils and solvents, water, fatty alcohols and fatty acid esters.
Emulsifiers have the function of introducing primary and secondary defoamers into the system to be treated.

There are basically two types of antifoam compositions containing silicone compounds. The first type is a composition utilizing a material having a certain minimum critical solution temperature, such as silicone polyether. The mode of use of such a material is to use it at a temperature above its minimum critical dissolution temperature, where the material loses solubility in water and thus acts as an antifoam. Due to the constraints on the minimum critical solution temperature, this type of defoaming composition has limited utility because it only works over a narrow temperature range.

US Pat. No. 5,106,535 teaches a silicone-based defoaming composition comprising a polyoxyalkylene-substituted organopolysiloxane, dimethyl silicone fluid and finely divided silica powder. To function as a defoamer, the composition described in U.S. Pat. No. 5,106,535 requires a surfactant to be dispersed in an aqueous system that controls foaming. A modification to the requirement that a surfactant be required for dispersion of the defoaming composition is disclosed in US Pat.
This is accomplished by incorporating into the composition a second polyoxyalkylene modified silicone that acts as a surfactant, as taught in US Pat.

US Pat. No. 5,169,561 describes a rare antifoam concentrate in which fine silica is treated with an antimicrobial agent to render the composition resistant to bacterial spoilage. A second, more traditional type of antifoam composition is an oil-in-water emulsion prepared by emulsifying a silicone polymer and finely divided silica. Emulsions of this type are generally very effective as defoamers, but are not stable to dilution. Oil-in-water emulsions, which function as defoamers, are thermodynamically unstable, and therefore have a purpose to increase the viscosity of the aqueous phase in order to slow the particle settling rate and thereby increase the storage stability of the emulsion. A thickener is added. When such an emulsion is diluted with water, the viscosity is reduced by the dilution, and the emulsion becomes unstable.

[0007]

There is a need for traditional types of defoamers that can be diluted to a wide range of concentrations and remain effective as defoamers.

[0008]

SUMMARY OF THE INVENTION We now have a water-in-oil emulsion that functions as a defoamer, which upon dilution changes phase to an oil-in-water emulsion that continues to function as a defoamer over a wide range of concentrations. A water-in-oil emulsion is disclosed. The present invention has the following components (a) ~ (e): (a) in from about 1 to about 99 wt% of the following general formula polyorganosiloxane MD _x M (the above ^{formula, M = R 1 R 2 R} 3 SiO 1 _{/ 2} (however,
R ¹ , R ² and R ³ are each independently selected from monovalent hydrocarbon groups having 1 to 40 carbon atoms), and D = R ⁴ R ⁵ SiO
_2/2 (provided that R ⁴ and R ⁵ each independently have 1 to 4 carbon atoms)
0 is selected from monovalent hydrocarbon groups), the subscript x representing the stoichiometric ratio is about 1 to about 10,000, and the viscosity of the polyorganosiloxane is about 1 to about 25 at 25 ° C.
(B) about 0.01 to about 50.0% by weight of finely divided silica having a mean particle size of about 0.001 to about 1000 μm; (c) about 0.10 to about 50 0.0% by weight, on average about 2
An emulsifier or emulsifier mixture having a hydrophilic-lipophilic ratio (HLB) of about 20; (d) a molecular weight of about 0.001 to about 20.0 wt.
From 0 to about 100,000,000 daltons of a thickener or a mixture of water-soluble thickeners selected from the group consisting of polyacrylates, polyamides, polyamines, styrene sulfonate polymers, polyethylene oxides and cellulose derivatives; and A water-in-oil emulsion comprising slightly more than about 20.0% by weight of water, the water-in-oil emulsion being added to water in an amount greater than the weight of the water-in-oil emulsion. Water-in-oil emulsions provide a water-in-oil emulsion that inverts to an oil-in-water emulsion that reduces foaming.

The present invention also provides a method for reducing foam,
The following steps (a) to (c): (a) the following components (i) to (v): (i) from about 1 to about 99% by weight of a polyorganosiloxane of the general formula MD _x M (where M is = R ¹ R ² R ³ SiO _1/2 (However,
R ¹ , R ² and R ³ are each independently selected from monovalent hydrocarbon groups having 1 to 40 carbon atoms), and D = R ⁴ R ⁵ SiO
_2/2 (provided that R ⁴ and R ⁵ each independently have 1 to 4 carbon atoms)
0 is selected from monovalent hydrocarbon groups), the subscript x representing the stoichiometric ratio is about 1 to about 10,000, and the viscosity of the polyorganosiloxane is about 1 to about 25 at 25 ° C.
(Ii) about 0.01 to about 50.0% by weight of finely divided silica having a mean particle size of about 0.001 to about 1000 μm; (iii) about 0.10 to about 50. 0.0% by weight, on average about 2
An emulsifier or emulsifier mixture having a hydrophilic-lipophilic ratio (HLB) of about 20; (iv) about 0.001 to about 20.0% by weight of a molecular weight of about 1;
From 0 to about 100,000,000 daltons of a thickener or water-soluble thickener mixture selected from the group consisting of polyacrylates, polyamides, polyamines, styrene sulfonate polymers, polyethylene oxides and cellulose derivatives; and (v) more than 0% by weight A water-in-oil emulsion comprising slightly more than about 20.0% by weight of water, the water-in-oil emulsion being added to water in an amount greater than the weight of the water-in-oil emulsion. Preparing a water-in-oil emulsion such that the water-in-oil emulsion inverts to a foam-reducing oil-in-water emulsion; (b) reducing the weight of the water-in-oil emulsion (C) adding the emulsion from a water-in-oil emulsion to an oil-in-water emulsion. Is phase inversion to also provides a method that thus to foam collapse rate comprising the step of to exceed the bubble generation rate.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises the following components (a) to
(E): (a) about 1 to about 99% by weight, preferably about 5 to about 95% by weight, more preferably about 25 to about 90% by weight, and most preferably about 60 to about 85% by weight of the following general formula: of the polyorganosiloxane MD _x M (the above ^{formula, M = R 1 R 2 R} 3 SiO 1/2 ( provided that
R ¹ , R ² and R ³ each independently represent a monovalent hydrocarbon group having 1 to 40 carbon atoms, preferably a monovalent hydrocarbon group having 1 to 20 carbon atoms, and more preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms. Hydrogen group, most preferably methyl, ethyl, n-propyl, i
-Propyl, trifluoropropyl, n-butyl, i-
Butyl, sec-butyl, n-pentyl, i-pentyl, neopentyl, n-hexyl, i-hexyl, phenyl and benzyl) and D = R ⁴ R ⁵ SiO
_2/2 (provided that R ⁴ and R ⁵ each independently have 1 to 4 carbon atoms)
0 monovalent hydrocarbon group, preferably a monovalent hydrocarbon group having 1 to 20 carbon atoms, more preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, most preferably methyl, ethyl, n-propyl, i- Propyl, trifluoropropyl, n-butyl, i-butyl, sec-butyl, n-pentyl, i-
Pentyl, neopentyl, n-hexyl, i-hexyl, phenyl and benzyl), and a subscript x representing a stoichiometric ratio is about 1 to about 10,000, preferably about 10 to about 5000, more preferably about 10 to about 5000. 50 to about 300
0, most preferably from about 100 to about 1000, wherein the viscosity of the polyorganosiloxane at 25 ° C is from about 1 to about 1
(B) about 100,000 centipoise at 25 ° C, preferably about 10 to about 1,000,000 centipoise at 25 ° C, more preferably about 50 to about 100,000 centipoise at 25 ° C, and most preferably about 100 to about 10,000 centipoise at 25 ° C); 0.01 to about 50.0% by weight, preferably about 0.10 to about 30.0% by weight, more preferably about 0.1 to about 50.0% by weight.
50 to about 20.0 wt%, most preferably about 1.0 to about 10.0 wt%, average particle size of about 0.001 to about 1000.
μm, preferably about 0.010 to about 100 μm in average particle size
m, more preferably about 0.050 to about 50μ average particle size
m, most preferably about 0.100 to about 10 μm average particle size
(C) about 0.10 to about 50.0% by weight, preferably about 1.0 to about 40.0% by weight, and more preferably about 5.0% by weight.
To about 30.0% by weight, most preferably from about 10.0 to about 2% by weight.
0.0% by weight, on average about 2 to about 20, preferably about 3
An emulsifier or an emulsifier mixture having a hydrophilic lipophilic ratio (HLB) of from about 18 to about 18, more preferably from about 4 to about 16, most preferably from about 5 to about 14; %, Preferably from about 0.010 to about 15.0% by weight, more preferably from about 0.050 to about 10.0% by weight, most preferably from about 0.
10 to about 5.0% by weight, molecular weight of about 100 to about 1000.
00000 daltons, preferably about 1000 to about 500
00000 daltons, more preferably about 10,000
About 100,000,000 daltons, most preferably about 100
000 to about 5,000,000 daltons of a thickener or thickener mixture which is a water-soluble polymer selected from the group consisting of polyacrylates, polyamides, polyamines, styrene sulfonate polymers, polyethylene oxides and cellulose derivatives; and (e) 0 weight % To about 20.0% by weight, preferably about 0.001 to about 15.0% by weight, more preferably about 0.050 to about 10.0% by weight, and most preferably about 0.100% by weight. This composition is an antifoam composition, although it relates to a water-in-oil emulsion comprising from about 5.0% by weight of water.

The choice of emulsifier is governed by two requirements: 1) compatibility in silicone, and 2) HLB. The emulsifier is required to be compatible with the silicone phase in order to provide a water-in-oil emulsion that will invert to an oil-in-water emulsion upon dilution. Compatibility in silicone can be determined by mixing silicone and emulsifier,
It can be determined by a simple test of heating between ° C. The mixture is maintained in this temperature range until a homogeneous mixture is obtained. The mixture of emulsifier and silicone is then cooled to room temperature. Applicants define a silicone-compatible emulsifier as an emulsifier that forms a homogenous mixture with the silicone after heating between 30 and 50 ° C. and then cooling to room temperature. Obviously, emulsifiers that do not form a homogeneous mixture are not compatible. Some emulsifiers will meet the criteria of this test independently of the silicone used, while others will depend on the viscosity of the silicone. The second condition imposed on the emulsifier is that the initially formed water-in-oil emulsion must undergo phase inversion to an oil-in-water emulsion when diluted with water.
Compatibility and the ability to invert the emulsion upon dilution are necessary and sufficient conditions for limiting the emulsifier.

A preferred class of emulsifiers is the ester derivatives of oleic acid. For example, mono-, di- and tri-glycerides of oleic acid, polyethylene oxide sorbitan mono-, di- and tri-oleates are preferred emulsifiers, ie, oleic acid surfactants. Within the range of the most preferred HLB values for emulsifiers, oleate derivatives having the following general formula have been found to be particularly effective.

[0013]

Embedded image

In the above formula, each Q is independently the formula-(CR ¹¹ R ¹²
Defined by _{^{CR 13 R 14 -O-) n -H}} . Where R ¹¹ and R
^12, R ¹³ and R ¹⁴ is a monovalent hydrocarbon group having 1 to 10 hydrogen or carbon atoms, n represents a 0 to about 100. The most preferred HLB range is 5-14. As this range is extended, the number of compatible surfactants that can be used to prepare a water-in-oil emulsion that will invert to an oil-in-water emulsion upon dilution increases. However, as this range is increased to less than 5 or 14 or more, the stability of the water-in-oil emulsion before dilution tends to be impaired.

The thickener is generally a water-soluble polymer, which may be anionic, nonionic or cationic, and may be solid or liquid. Generally, any suitable thickener may be used so long as the emulsion is not disrupted by the thickener. The thickener can be any suitable water-soluble polymer that does not disrupt the emulsion. Particularly preferred thickeners are water-soluble polymers having a molecular weight of about 100 to about 100,000,000 daltons, selected from the group consisting of polyacrylates, polyamides, polyamines, styrene sulfonate polymers, polyethylene oxides and cellulose derivatives.

The water-in-oil emulsion defoamer of the present invention is generally prepared by mixing silicone, a water-soluble polymer, an emulsifier, water and an optional neutralizing agent. The present invention is illustrated by the following examples, which do not limit the scope of the claims. All U.S. patents cited herein are hereby incorporated by reference.

[0017]

EXAMPLES Examples 1-3 Table 1 shows the weights of the various components used to prepare the water-dilutable antifoam compositions.

[0018]

[Table 1]

Notes for Table 1: AF9000® is available from GE Silicones, Waterford, NY, USA.
It is an antifoaming composition containing hexamethyldisilazane-treated silica and polydimethylsiloxane manufactured by Azbil Corporation. 2. Arlacel 186® is a trademark of ICI Ameri, Wilmington, Del., USA.
cas) is a mixture of mono- and di-glycerides of lipogenic fatty acids. 3. Polysorbate 80® is a trademark of ICI Americas of Wilmington, Delaware, U.S.A.
Americas) polyethylene oxide (20) sorbitan monooleate. 4. SF96-350® is available from GE Silicones, Waterford, NY, USA.
nes) Polydimethylsiloxane having a viscosity of 350 centipoise at 25 ° C. 5. EMA10® is a polymer emulsion containing a copolymer of acrylamide and sodium acrylate manufactured by Chemtall of Riceboro, Georgia, USA.

Example 4 A concentrated antifoam composition was prepared as follows. 30g Spa
n 80 (registered trademark) (ICI Americas
s) Sorbitan monooleate from Co., Ltd., 70 g Tween
en 85® (ICI Ameris)
cas) polyethylene oxide (20) sorbitan trioleate), 180 g SF96-350 and 20
g of hexamethyldisilazane treated precipitated silica,
Homogenized until uniform. 38 g of the mixture thus prepared was blended with 2 g of EM533® (a water-in-oil emulsion of about 40% by weight of acrylamide-sodium acrylate copolymer). The resulting antifoam concentrate was an emulsion that could be easily diluted with water.

EXAMPLE 5 40.2 g of a mixture of 5 to 15% by weight of hexamethyldisilazane-treated fumed silica and 85 to 95% by weight of hexamethyldisilazane-treated precipitated silica and polydimethyl having a viscosity of 350 centipoise at 25 ° C. A premix of 361.8 g of siloxane was homogenized until uniform. 11. Add 68.0 g of Span 80® to this silicone oil-silica mixture and 12.
7 g of Tween 85® was added and mixed well. This premix was used to prepare yet another antifoam concentrate. In the following examples, this premix is referred to as premix A.

Example 6-9

[0023]

[Table 2]

Notes to Table 2: (1) SF 18-350 is a polydimethylsiloxane having a viscosity of 350 centipoise at 25 ° C., manufactured by GE Silicones of Waterford, NY. (2) EMA 533® is a water-in-oil emulsion containing about 40% by weight acrylamide-sodium acrylate copolymer manufactured by Chemtall of Riceboro, Georgia, USA.

Example 10 200 g of Premix A (Example 5) was mixed with 26.41 g of S
pan 80® and 23.73 g Tween
n 85®, then 249.87 g
Premix B was made by adding SF 18-350 of the above. Example 11 To 300 g of Premix B was added 6.1 g of Pemule
n TR-1®, 2.30 g of 50% by weight N
An aqueous aOH solution and 5 g of water were added. Pemulen
TR-1 (R) is available from B.C. of Cleveland, Ohio, USA. F. Polyacrylic acid manufactured by BF Goodrich. This preparation could be diluted with water.

Example 12 96 g of 10 g of Pemulen TR-1®
g of water was added to prepare an aqueous slurry of 9.43% by weight of Pemulen TR-1®. This P
aqueous slurry of emulen TR-1 (registered trademark) 2
To 2 g, add 200 g of Premix B, then add 50 g
0.65 g of a weight% NaOH aqueous solution was added. This preparation could be diluted with water.

EXAMPLE 13 532.6 pounds of SF 18-35 large reaction kettle
62 pounds of a mixture of 0.5 to 15% by weight hexamethyldisilazane treated fumed silica and 85 to 95% by weight hexamethyldisilazane treated precipitated silica and 0.6 pounds of oleic acid were charged. The mixture was heated to 120 ° C. with stirring. After stirring at 120 ° C. for 4 hours,
The mixture was cooled to 25C. Followed by 24.8 pounds of P
emulen TR-1® was added and the mixture was mixed until homogeneous. The resulting mixture is Gauli
The second reaction was transferred to the kettle by homogenization with an n mixer. The second reaction containing the homogenized mixture is
2.8 pound Span 80®, 107.
8 lb Tween 85® and 953.
After adding 2 pounds of SF 18-350, mix for 2 hours. While mixing the mixture, 62 pounds of water at a temperature of 20-35 ° C was added. One hour after starting mixing, 8
One pound of Proxel GXL®, two pounds of methylparaben and two pounds of propylparaben were added as a disinfectant package. When all the ingredients were mixed, 42.2 pounds of a 10% by weight aqueous NaOH solution was added.

This preparation was diluted by changing the amount of water as shown in Table 3.

[0029]

[Table 3]

The viscosity of each diluted preparation of Example 13 was adjusted by adding a 10% aqueous acetic acid solution. The pH was changed by adding sufficient acetic acid solution, thereby changing the viscosity of the diluted preparation. As shown in Table 4, the viscosity of the antifoam concentrate significantly changed by a relatively slight change in pH.

[0031]

[Table 4]

Claims (10)

[Claims] 1. A following components (a) ~ (e): (a) from about 1 in to about 99 wt% of the following general formula polyorganosiloxane MD _x M (the above ^{formula, M = R 1 R 2 R} 3 SiO _1/2 (however,
R ¹ , R ² and R ³ are each independently selected from monovalent hydrocarbon groups having 1 to 40 carbon atoms), and D = R ⁴ R ⁵ SiO
_2/2 (provided that R ⁴ and R ⁵ each independently have 1 to 4 carbon atoms)
0 is selected from monovalent hydrocarbon radicals), the stoichiometric subscript x is from about 1 to about 10,000, and the viscosity of the polyorganosiloxane is from about 1 to about 100,000,000 centipoise at 25 ° C. (B) about 0.01 to about 50.0% by weight of finely divided silica having an average particle size of about 0.001 to about 1000 μm; (c) about 0.10 to about 50.0% by weight %, On average about 2
An emulsifier or emulsifier mixture having a hydrophilic-lipophilic ratio (HLB) of about 20; (d) a molecular weight of about 0.001 to about 20.0 wt.
From 0 to about 100,000,000 daltons of a thickener or a mixture of water-soluble thickeners selected from the group consisting of polyacrylates, polyamides, polyamines, styrene sulfonate polymers, polyethylene oxides and cellulose derivatives; and A water-in-oil emulsion comprising slightly more than about 20.0% by weight of water, the water-in-oil emulsion being added to water in an amount greater than the weight of the water-in-oil emulsion. Water-in-oil emulsions are phase-inverted oil-in-water emulsions that reduce foam. 2. The water-in-oil emulsion of claim 1, wherein said emulsifier has a hydrophilic to lipophilic ratio of from about 3 to about 18. 3. The emulsifier is an ester of oleic acid and has a hydrophilic to lipophilic ratio of about 5 to about 14.
A water-in-oil emulsion as described. 4. The water-in-oil emulsion according to claim 3, wherein the ester of oleic acid is of the following formula: Embedded image Wherein each Q is independently of the formula-(CR ¹¹ R ¹² CR ¹³ R ¹⁴ -O-) _n
-H (where R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are hydrogen or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and n is 0 to about 10
0). 5. The water-in-oil emulsion according to claim 3, wherein the ester of oleic acid comprises a glycerin ester. 6. The water-in-oil emulsion according to claim 3, wherein the ester of oleic acid comprises glycerin monoester. 7. The water-in-oil emulsion of claim 3, wherein said ester of oleic acid comprises glycerin triester. 8. A method for reducing foam, comprising:
-(C): (a) preparing the water-in-oil emulsion according to claim 1; (b) adding the water-in-oil emulsion to water having a weight exceeding the weight of the water-in-oil emulsion. And (c) inverting the emulsion from a water-in-oil emulsion to an oil-in-water emulsion, such that the rate of foam collapse exceeds the rate of foam formation. 9. A method for reducing foam, comprising:
-(C): (a) preparing the water-in-oil emulsion according to claim 2; (b) adding the water-in-oil emulsion to water having a weight exceeding the weight of the water-in-oil emulsion. And (c) inverting the emulsion from a water-in-oil emulsion to an oil-in-water emulsion, such that the rate of foam collapse exceeds the rate of foam formation. 10. A method for reducing foam, comprising the following steps (a) to (c): (a) preparing the water-in-oil emulsion according to claim 3; (b) preparing the water-in-oil emulsion. Adding to the water in an amount greater than the weight of the water-in-oil emulsion; and (c) inverting the emulsion from a water-in-oil emulsion to an oil-in-water emulsion; A method comprising increasing speed.