Defoaming agent / foam breaker

Abstract

To provide a fatty acid ester of polyoxyethylene as an additive / accelerator to reduce foaming in an aqueous alkali medium and to provide a preparation method of the additive / accelerator.SOLUTION: A defoaming accelerator has a structural formula (I) or (Ia) expressed as linear A-B-C-B-A (structural formula (I)) or tetra arm [A'-B'] 4C'(structural formula (Ia)) where, A is a part of fatty acid; B is a part of dialcohol; C is a part of aliphatic diacid; A' is a part of aliphatic alcohol; B' is a part of aliphatic diacid; C' is a part of tetra alcohol; the fatty acid is selected from among myristic acid, stearic acid and hexa decene acid;the dialcohol is selected from among PEG-400 and polypropylene glycol; and the aliphatic diacid is selected from among sebacic acid, adipic acid and suberic acid.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an antifoaming / defoaming compound having foam breaking effect and a method for preparing the same. The present invention also relates to an antifoaming formulation having additives and accelerators. [Background technology]

[0002] According to the traditional concept, a foam is a dispersion system, where the dispersed part is a gas and the dispersant is a liquid. In many industrial processes involving the treatment of liquids or with liquids, foam formation is a frequent problem. Such foaming problems are often accentuated in the presence of soluble metal salts, insoluble salt particles, other organic components or entrapments. Foaming of liquids contributes to the reduction of process efficiency and product quality.

[0003] To mitigate the efficiency losses associated with foaming, additives are used in industrial processes. To solve the foaming problems of liquids, additives such as antifoaming / defoaming agents are used, which have the effect of breaking down bubbles (i.e., foam breaking effect) or suppressing the generation of bubbles (i.e., foam suppression effect). The essence of additive-based foam control mechanisms is that the antifoaming agent itself accumulates at the gas-liquid interface, destroying the stability of the foam but is unable to form a new ordered monolayer. Commonly used antifoaming agents are water-insoluble oils such as silicones, certain alcohols, stearates, and glycols.

[0004] Antifoam / defoaming additives are often emulsified mixtures of polyethers and fatty acids and / or fatty acid esters. Many additive formulations are fatty acid-based emulsion products. Some examples of fatty acid-based emulsion products are described in the following prior art:

[0005] No. 3,705,860A relates to an improved defoamer particularly suitable for use in paper and pulp manufacturing processes, which is prepared from a mixture of non-polar oils, precipitated silica, organometallic catalysts, polymethylsiloxane and microcrystalline paraffin wax. These defoamers are also useful in the manufacture of latex paints.

[0006] US3337595A relates to novel compounds, namely fatty acid esters of polyoxypropylated glycerol, which have been shown to be useful for controlling, inhibiting and / or preventing foaming in aqueous systems having a tendency to foam.

[0007] DE 3013292 relates to a process for preparing a free-flowing form of an antifoam agent which has a low melting or softening point and therefore a tendency to cake on storage.

[0008] US4451390A relates to compositions for controlling undesirable foaming, comprising soybean oil, mineral oil, fine silica, unsubstituted fatty acid monoesters of glycerol, and unsubstituted fatty acid esters of polyoxyalkylated sorbitan. These compositions are particularly useful for controlling foaming in fermentation, since they are stable to sterilization. They can also be used in paints, since they do not have the drawbacks common to silicone-based antifoaming agents.

[0009] Antifoam / defoaming additives are often emulsified mixtures of polyethers and fatty acids, and / or fatty acid esters. Many additive formulations are fatty acid-based emulsion products. Linear organic esters containing two chemically dissimilar hydrophilic and hydrophobic chain ends are preferred because they can be tailored to be chemically robust yet essentially noncorrosive.

[0010] The primary object of the present invention is to provide fatty acid esters of polyoxyethylene as additives / enhancers for reducing foaming in aqueous alkaline media.

[0011] Another object of the present invention is to provide an antifoam formulation comprising a fatty acid ester of polyoxyethylene as an additive and a tetraarm derivative as an enhancer which enhances the foam reducing tendency of the additive.

[0012] It is yet another object of the present invention to provide an antifoam formulation that does not undergo phase separation and has reduced handling and use limitations. Summary of the Invention

[0013] The present invention provides a series of fatty acid esters of polyoxyethylene with gradually varying fatty acid chain lengths of the series of fatty acid polyol esters. Selected fatty acids were further used to prepare alternative triblock (ABA) and pentablock (ABCBA) chains and their relative effectiveness was confirmed. Finally, the tetraarm [A'-B'] 4 C' type molecules were prepared, and their non-linear structure allowed for even greater foaming tendency. All designs were achieved through a scalable esterification reaction. Because the fatty acids are chemically bonded to the polyol chain, the resulting liquid materials do not undergo phase separation, easing handling and usage restrictions.

[0014] In one embodiment of the disclosure, there is provided a defoaming promoter having the following structural formula (I) or (Ia): Linear ABCBA (I), or Tetra Arm [A´-B´] 4 C´ (Ia) Where: A is the fatty acid moiety, B is the dialcohol portion, C is the fatty di-acid moiety, A' is the aliphatic alcohol moiety, B' is the aliphatic diacid moiety; C' is the tetraalcohol portion.

[0015] In another embodiment, the present invention provides a defoamer booster, wherein the fatty acid is selected from myristic acid, stearic acid, and hexadecenoic acid, the dialcohol is selected from PEG-400 and polypropylene glycol, and the aliphatic diacid is selected from sebacic acid, adipic acid, and suberic acid.

[0016] In the structural formula (I) of the defoaming promoter, structural formula (I) is compound 9 shown below. TIFF2025026278000002.tif30161

[0017] In another embodiment, the present invention provides a method for synthesizing compound 9 by a process comprising the following steps: (a) adding the following compound 8 and myristic acid in toluene to obtain a reaction mixture; and TIFF2025026278000003.tif30129 (b) heating the reaction mixture obtained in step (a) for 4-8 hours with constant stirring to obtain compound 9.

[0018] In one preferred aspect of the invention, heating of the reaction mixture in the synthesis of compound 9 is carried out at 110°C.

[0019] In another embodiment, the present invention provides a method for synthesizing compound 8 by a process comprising the following steps: (a) adding sebacic acid and PEG-400 in toluene to obtain a reaction mixture; and (b) heating the resulting reaction mixture for 4-8 hours with constant stirring to give compound 8.

[0020] In one preferred aspect of the invention, heating of the reaction mixture in the synthesis of compound 8 is carried out at 110°C.

[0021] In another embodiment, the present invention provides a tetraarm [A'-B'] 4The present invention provides a defoaming promoter having the structure C', wherein the fatty alcohol is selected from myristyl alcohol, stearyl alcohol, and dodecanol, the fatty diacid is selected from sebacic acid, adipic acid, and suberic acid, and the tetraalcohol is selected from pentaerythritol, erythritol, and threitol.

[0022] In the structural formula (Ia) of the defoaming promoter, structural formula (Ia) is compound 10 shown below. TIFF2025026278000004.tif53129

[0023] In another embodiment, the present invention provides a method for synthesizing antifoam compound 10 by a process comprising the following steps: (a) adding sebacic acid and myristyl alcohol in toluene to obtain a reaction mixture; (b) heating the reaction mixture obtained in step (a) for 4 to 8 hours with constant stirring; and (c) adding pentaerythritol to the reaction mixture obtained in step (b) and continuing to stir for an additional 8 to 16 hours to obtain compound 10;

[0024] In one preferred aspect of the invention, heating of the reaction mixture in the synthesis of compound 10 is carried out at 110°C.

[0025] In another embodiment, the present invention provides an antifoam formulation comprising: (a) an additive which is compound 4 below, and TIFF2025026278000005.tif30129 (b) a promoter as disclosed herein.

[0026] In other embodiments, the present invention provides an antifoam formulation, wherein the enhancer is compound 9, compound 10, or a combination thereof.

[0027] In one preferred aspect of the invention, the antifoam formulation has a ratio of Compound 4:Compound 10 of 19:1.

[0028] In yet another embodiment, the present invention provides a foam reduction process comprising incorporating an antifoam formulation into a foam-generating material, wherein the amount of antifoam formulation is between 1 and 20 ppm of the foam-generating material.

[0029] In another embodiment, the present invention provides a foam reduction process, where foam reduction occurs at any gas-liquid interface where the liquid phase is an alkaline aqueous medium. [Brief description of the drawings]

[0030] [Figure 1] The diagram shows the structures of the synthesized compounds, from the left: linear diblock AB type, linear triblock ABA type, linear pentablock ABCBA type, and tetraarm [A'-B']4C' type. [Diagram 2] FIG. 2 illustrates the mechanism of bubble bursting in the presence of additives and accelerators. [Diagram 3] FIG. 1 shows the experimental design for calculating the foam reduction efficiency of an additive in the presence of an additive and a promoter compared to a blank solution. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] In order to facilitate the understanding of the principles of the present invention, specific embodiments are described below. However, it is not intended to limit the scope of the present invention, and it should be understood that the changes and modifications in the illustrated process, and further application of the illustrated principles of the present invention are contemplated as those that are normally performed by those skilled in the art to which the present invention belongs. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The compositions, methods and examples provided herein are illustrative only and are not intended to be limiting.

[0032] The articles "a," "an," and "the" refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.

[0033] The terms "comprise" and "comprising" are used in an inclusive, open sense, meaning that additional elements may be included. It is not intended to be interpreted as "consisting only of." Throughout this specification, unless the context requires otherwise, the word "comprise" and variations such as "comprises" and "comprising" should be understood to mean the inclusion of a stated element or step, or group of elements or steps, but not the exclusion of other elements or steps, or group of elements or steps.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs.Although any method and material similar or equivalent to those described herein can be used in the practice or testing of this disclosure, preferred methods and materials are described herein.All publications described herein are incorporated herein by reference.

[0035] In the present invention, linear diblock esters of polyether derivatives and fatty acid derivatives were synthesized by using the components in a molar ratio of 1:1 and refluxing at 110° C. in toluene as a solvent.

[0036] A linear triblock ester in which the central block is a polyether derivative was synthesized by refluxing at 110°C in toluene as a solvent using a polyether and a fatty acid in a molar ratio of 1:2 as building blocks.

[0037] Linear triblock esters, in which the center block ester is a linear diacid, were prepared using a 1:2 molar ratio of linear di-acid and polyether at reflux at 110° C. in toluene.

[0038] Similarly, the open polyether chain ends can be further esterified to prepare linear pentablock esters. Diblock linear esters of diacids and aliphatic alcohols were coupled with pentaerythritol under similar reaction conditions to give tetraarm derivatives (e.g., compound 10).

[0039] Chart I: Shown below are structures of compounds 1-10 of the present disclosure. TIFF2025026278000006.tif107135

[0040] [Table 1]

[0041] The present invention will be described below with reference to examples. However, those skilled in the art should understand in light of this disclosure that many modifications can be made to the specific embodiments disclosed to obtain the same or similar results without departing from the spirit and scope of the present invention. It should be understood that the examples are provided for the purpose of illustrating the present invention and are not intended to limit the scope of the present invention in any way.

[0042] Example 1: Synthesis of Compounds 1 to 5 40 g of PEG-400 (100 mmol) and 8.81 g of butanoic acid (100 mmol) were taken in a 250 mL round-bottom flask along with 100 mL of toluene. The reaction mixture was heated to 110 °C with constant stirring for 8 h and the released water was separated from the refluxing medium using a Dean-Stark trap. After completion of the reaction, the solvent was evaporated under vacuum to obtain the desired product (1) as a colorless liquid (yield >99%). Following a similar procedure, compounds 2-5 were obtained using 100 mmol of fatty acid instead of butanoic acid. All compounds were obtained as colorless liquids (see Table 1). JPEG2025026278000008.jpg33129 where R is a linear or branched alkyl group, n is 10 to 25.

[0043] Example 2: Synthesis of Compounds 6 and 7 40 g of PEG-400 (100 mmol) and 45.70 g of myristic acid (200 mmol) were taken in a 250 mL round-bottom flask along with 100 mL of toluene. The reaction mixture was heated to 110 °C with constant stirring for 8 h and the released water was separated from the refluxing medium using a Dean-Stark trap. After completion of the reaction, the solvent was evaporated under vacuum to obtain the desired product (6) as a colorless liquid (yield >99%). Compound 7 was synthesized following a similar procedure, using 200 mmol of diacid instead of myristic acid. Compound 7 was isolated as a white solid (see Table 1). JPEG2025026278000009.jpg35129 where R is any straight chain alkyl group. n is 10 to 25.

[0044] Example 3: Synthesis of compound 8 20.22 g of sebacic acid (100 mmol) and 80 g of PEG-400 (200 mmol) were taken in a 250 mL round-bottom flask along with 100 mL of toluene. The reaction mixture was heated to 110 °C with constant stirring for 8 h and a Dean-Stark trap was used to separate the released water from the refluxing medium. After completion of the reaction, the solvent was evaporated under vacuum to give the desired product (8) as a colorless liquid (yield >98%) (see Table 1). JPEG2025026278000010.jpg30137 where n is 10 to 25; m is 8.

[0045] Example 4: Synthesis of Compound 9 96.6 g of compound 8 (100 mmol) and 45.70 g of myristic acid (200 mmol) were taken in a 250 mL round-bottom flask along with 100 mL of toluene. The reaction mixture was heated to 110 °C with constant stirring for 8 h, and the released water was separated from the refluxing medium using a Dean-Stark trap. After completion of the reaction, the solvent was evaporated under vacuum to give the desired product (9) as a colorless liquid (yield >97%) (see Table 1). 1 H NMR (500MHz, CDCl 3 ):σ4.2(m,8H),3.7(m,40H),2.4(m,8H),1.7(m,8H),1.3(m,48H),0.9(t,6H). FTIR 2920cm -1 ,2850cm -1 ,1735cm -1 ,1450cm -1 ,1350cm -1 ,1250cm -1 ,1100cm -1 ,725cm -1 ,695cm -1 . JPEG2025026278000011.jpg30161 where n is 10 to 25; m is 8.

[0046] Example 5: Synthesis of Compound 10 20.22 g of sebacic acid (100 mmol) and 21.4 g of myristyl alcohol (100 mmol) were taken in a 250 mL round bottom flask along with 100 mL of toluene. The reaction mixture was heated to 110 °C with constant stirring for 8 h and a Dean-Stark trap was used to separate the released water from the refluxing medium. Further, 3.4 g of pentaerythritol (25 mmol) was added to the reaction mixture and allowed to react for another 16 h. After completion of the reaction, the solvent was evaporated to obtain the desired compound as a low melting white solid (see Table 1). 1 H NMR (500 MHz, CDCl 3 ):σ4.25(t,8H),3.7(m,8H),2.3(m,16H),1.6(m,24H),1.3(m,120H),0.9(t,12H). FTIR 2950cm -1 ,2915cm -1 ,2850cm -1 ,1731cm -1 ,1700cm -1 ,1420cm -1 ,1300cm -1 ,1215cm -1 ,1175cm -1 ,715cm -1 . JPEG2025026278000012.jpg52162

[0047] Example 6: Evaluation of formulations The foaming test was performed by measuring the equilibrium foam height. For example, blank / reference solutions and test solutions containing additives were diluted with N 2 The foam was then subjected to a constant purge of nitrogen and the equilibrium heights were compared to determine the percentage foam reduction as a function of the additive. 3 )·9H 2 A solution containing 0.5 wt % O (iron nitrate nonhydrate) was used as the blank / reference solution (see FIG. 3 and Table 2).

[0048] An equal volume of blank / standard solution was added to the equilibrium nitrogen (N 2) under purging and compared to an additive-containing solution, i.e., all conditions in the two parallel setups were kept the same except that one solution contained the additive formulation. The foam reduction rate was calculated according to the following formula. Foam reduction rate (%) = Δh ÷ h (blank) × 100

[0049] [Table 2]

[0050] After comprehensive screening of various additives, it was possible to identify the optimal additive (compound 4) and further find the optimal formulation (compound 4 and compound 10 in a ratio of 19:1) in combination with various accelerators. The tetra-arm design acts as a performance enhancer for linear systems, as the non-linear structure makes the foam surface more unstable. The final formulation was able to reduce the foaming of the medium by up to 95% when compared to the reference solution.

Claims

1. A defoaming promoter having the following structural formula (I) or (Ia): Linear ABCBA (I), or Tetra arm [A'-B'] ４ C' (Ia) Where: A is the fatty acid moiety, B is the dialcohol portion, C is an aliphatic diacid moiety; A' is an aliphatic alcohol moiety, B' is an aliphatic diacid moiety; C' is a defoaming promoter which is a tetraalcohol moiety.

2. The defoaming promoter according to claim 1, the fatty acid is selected from myristic acid, stearic acid, and hexadecenoic acid; the dialcohol is selected from PEG-400 and polypropylene glycol; A defoaming promoter wherein said aliphatic diacid is selected from sebacic acid, adipic acid, and suberic acid.

3. The defoaming promoter according to claim 1, The defoaming promoter, wherein the structural formula (I) is compound 9 below.

4. A method for preparing compound 9, comprising the steps of: (a) adding the following compound 8 and myristic acid in toluene to obtain a reaction mixture; (b) heating the reaction mixture obtained in step (a) for 4-8 hours under constant stirring to obtain compound 9; The method includes:

5. 5. The method of claim 4, wherein the heating of the reaction mixture is performed at 110°C.

6. 5. The method of claim 4, wherein the compound 8 is (a) adding sebacic acid and PEG-400 in toluene to obtain a reaction mixture; (b) heating the resulting reaction mixture with constant stirring for 4 to 8 hours; The method is synthesized by a process including:

7. 7. The method of claim 6, wherein the heating of the reaction mixture is performed at 110°C.

8. The defoaming promoter according to claim 1, the fatty alcohol is selected from myristyl alcohol, stearyl alcohol, and dodecanol; the aliphatic diacid is selected from sebacic acid, adipic acid, and suberic acid; The tetra-alcohol is selected from pentaerythritol, erythritol, and threitol.

9. The defoaming promoter according to claim 1, The defoaming promoter, wherein the structural formula (Ia) is compound 10:

10. A process for preparing compound 10, comprising the steps of: (a) adding sebacic acid and myristyl alcohol in toluene to obtain a reaction mixture; (b) heating the reaction mixture obtained in step (a) for 4 to 8 hours with constant stirring; and (c) adding pentaerythritol to the reaction mixture obtained in step (b) and continuing stirring for an additional 8 to 16 hours to obtain compound 10; The method includes:

11. 11. The method of claim 10, wherein the heating of the reaction mixture is performed at 110°C.

12. 1. An antifoam formulation comprising: (a) an additive of compound 4 below, (b) an accelerator according to claim 1; 13. An antifoam formulation comprising:

13. 13. The antifoam formulation of claim 12, wherein the enhancer is compound 9, compound 10, or a combination thereof.

14. 14. The antifoam formulation according to claim 12 or 13, wherein the ratio of compound 4:compound 10 is 19:

1.

15. 14. A process for reducing foam comprising incorporating an antifoam formulation according to claim 12 or 13 into a foam-producing material, the amount of antifoam formulation being 1-20 ppm of the foam-producing material.

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