Dispersed defoaming agent

Abstract

The purpose of the present invention is to provide a defoaming agent capable of exhibiting exceptional defoaming properties (foam breaking and foam suppressing effects) and exceptional surface finish properties (cissing and foam breaking effects). The present invention is a dispersed defoaming agent characterized by containing a dispersoid composed of a liquid glycerin fatty acid ester (A), a dispersion medium composed of a liquid alkylene oxide adduct (B), and at least one hydrophobic substance (C) selected from the group consisting of hydrophobic silica, fatty acid metal salts, fatty acid amides, and waxes, the amount of the liquid glycerin fatty acid ester (A) being 4-49 wt%, the amount of the liquid alkylene oxide adduct (B) being 51-96 wt%, and the amount of the hydrophobic substance (C) being 0.1-15 wt%, on the basis of the weight of the liquid glycerin fatty acid ester (A) and the liquid alkylene oxide adduct (B).

Description

Dispersed defoamer

[0001] The present invention relates to a dispersible defoamer.

[0002] A known antifoaming agent composition is "comprised of, as essential components, 40 to 90% by mass of (A) a sorbitan oleate ester, 5 to 60% by mass of (B) an edible oil or fat having a melting point of 10°C or lower, and 0.5 to 5% by mass of (C) a polyoxyethylene sorbitan fatty acid ester" (Patent Document 1).

[0003] JP 2014-210215 A

[0004] Conventional defoaming agents have a problem in that they are unable to provide good surface finish (cissing and traces of broken bubbles) while maintaining excellent defoaming properties (foam breaking and foam suppression effects). An object of the present invention is to provide a defoaming agent that can exhibit excellent defoaming properties (foam breaking and foam suppression effects) as well as excellent surface finish (cissing and traces of broken bubbles).

[0005] The dispersed defoaming agent of the present invention is characterized in that it comprises a dispersoid comprising a liquid glycerin fatty acid ester (A), a dispersion medium comprising a liquid alkylene oxide adduct (B), and at least one hydrophobic substance (C) selected from the group consisting of hydrophobic silica, fatty acid metal salts, fatty acid amides, and waxes, and the content of the liquid glycerin fatty acid ester (A) is 4 to 49% by weight, the content of the liquid alkylene oxide adduct (B) is 51 to 96% by weight, and the content of the hydrophobic substance (C) is 0.1 to 15% by weight, based on the weights of the liquid glycerin fatty acid ester (A) and the liquid alkylene oxide adduct (B).

[0006] The water-based resin emulsion of the present invention is characterized in that it contains the above-mentioned dispersed defoaming agent, water, and a resin.

[0007] The defoaming agent of the present invention has excellent defoaming properties (foam breaking and foam suppression effects) as well as excellent surface finish (cissing and broken foam marks).

[0008] The aqueous resin emulsion of the present invention contains the above-mentioned dispersed defoaming agent, and therefore exhibits excellent defoaming properties (foam breaking and foam suppression effects) as well as excellent surface finish (cissing and foam breakage marks).

[0009] 1 is a photograph of the phase state of the dispersed defoaming agent of the present invention prepared in Example 1, taken with a phase contrast microscope (200x magnification).

[0010] As the liquid glycerin fatty acid ester (A), any glycerin fatty acid ester that is liquid (viscosity of 0.1 to 50,000 mPa·s) at 25° C. can be used without any restrictions.

[0011] Examples of the liquid glycerin fatty acid ester (A) include esters of glycerin with a fatty acid having 6 to 22 carbon atoms or a mixture thereof (glycerin fatty acid triester, glycerin fatty acid diester, and glycerin fatty acid monoester), and examples thereof include vegetable oils (rapeseed oil, soybean oil, palm oil, coconut oil, olive oil, etc.), fish oils (anchovy oil, tuna oil, herring oil, salmon oil, krill oil, cod liver oil, etc.), fatty acid triglycerides (trade names such as Panasate 875; NOF Corporation, "Panasate" is a registered trademark of the company in Japan), and fatty acid mono- and diglycerides (trade names such as Poem OL-200VM, Glycerin Monodiolate, Riken Vitamin Co., Ltd., "Poem" is a registered trademark of the company in Japan).

[0012] The content (wt %) of the liquid glycerin fatty acid ester (A) based on the weight of the liquid glycerin fatty acid ester (A) and the liquid alkylene oxide adduct (B) is preferably 4 to 49, more preferably 8 to 48, and particularly preferably 15 to 47. Within this range, the defoaming properties and surface finish are further improved.

[0013] The liquid alkylene oxide adduct (B) can be any alkylene oxide adduct that is liquid (0.1 to 50,000 mPa s) at 25° C. without any limitations. When the liquid alkylene oxide adduct (B) contains a plurality of alkylene oxide adducts, it is sufficient that the mixture as a whole is liquid.

[0014] The liquid alkylene oxide adduct (B) includes alkylene oxide adducts of active hydrogen compounds and fatty acid esters of alkylene oxide adducts of active hydrogen compounds.

[0015] In the liquid alkylene oxide adduct (B), the alkylene oxide is at least one selected from the group consisting of ethylene oxide, propylene oxide, and alkyl glycidyl ethers. Examples of the alkyl glycidyl ether include alkyl glycidyl ethers having 4 to 18 carbon atoms, such as methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, dodecyl glycidyl ether, and octadecyl glycidyl ether.

[0016] A plurality of types of alkylene oxides (oxyalkylene groups) may be contained, and when a plurality of types of alkylene oxides (oxyalkylene groups) are contained, they may be in a random form, a block form, or a mixture thereof.

[0017] In the liquid alkylene oxide adduct (B), the proportion (wt %) of oxyethylene groups among the oxyalkylene groups constituting the alkylene oxide adduct is preferably 0 to 60 based on the weight of the oxyalkylene groups, but when the oxyalkylene groups contain oxyethylene groups, the proportion (wt %) of oxyethylene groups is preferably 1 to 60, more preferably 2 to 50, and particularly preferably 4 to 40. Within this range, the defoaming properties and surface finish are further improved.

[0018] The number of moles (moles) of alkylene oxide added to the alkylene oxide adduct relative to 1 mole (equivalent) of active hydrogen of the active hydrogen compound is preferably 1 to 100, more preferably 2 to 75, and particularly preferably 5 to 60. Within this range, the defoaming properties and surface finish are further improved.

[0019] The active hydrogen compounds include hydroxyl groups (-OH), imino groups (-NH-), and amino groups (-NH ２ ) and / or a carboxyl group (—COOH), and includes alcohols, amides, amines, carboxylic acids, hydroxycarboxylic acids, and glycerides having a hydroxyl group.

[0020] Examples of alcohols include monools (methanol, butanol, stearyl alcohol, oleyl alcohol, isostearyl alcohol, etc.) and polyols (ethylene glycol, propylene glycol, glycerin, diglycerin, tetraglycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, dihydroxyacetone, fructose, glucose, mannose, galactose, sucrose, lactose, trehalose, etc.).

[0021] Examples of the amide include monoamides (formic acid amide, propionic acid amide, stearyl amide, etc.) and polyamides (malonic acid diamide, ethylene bis octyl amide, etc.).

[0022] Examples of the amine include monoamines (dimethylamine, ethylamine, aniline, stearylamine, etc.) and polyamines (ethylenediamine, diethylenetriamine, triethylenetetramine, etc.).

[0023] Carboxylic acids include monocarboxylic acids (such as acetic acid, propanoic acid, 2-ethylhexanoic acid, stearic acid, oleic acid, and benzoic acid) and polycarboxylic acids (such as maleic acid and hexanedioic acid).

[0024] Examples of hydroxycarboxylic acids include hydroxyacetic acid, tartaric acid, malic acid, and 12-hydroxystearic acid.

[0025] Examples of glycerides having a hydroxyl group include carboxylic acid monoglycerides (such as glycerin monoricinolate), carboxylic acid diglycerides (such as glycerin diricinolate), and carboxylic acid triglycerides (such as castor oil, hydrogenated castor oil, and glycerin triricinolate).

[0026] Among the active hydrogen compounds, alcohols and glycerides having a hydroxyl group are preferred from the viewpoints of defoaming properties and surface finish. That is, the liquid alkylene oxide adduct (B) is preferably at least one selected from the group consisting of alkylene oxide adducts of alcohols, alkylene oxide adducts of glycerides having a hydroxyl group, and fatty acid esters thereof.

[0027] Examples of fatty acids that can constitute the fatty acid ester of the alkylene oxide adduct of an active hydrogen compound include the above-mentioned monocarboxylic acids.

[0028] The content (wt %) of the liquid alkylene oxide adduct (B) based on the weight of the liquid glycerin fatty acid ester (A) and the liquid alkylene oxide adduct (B) is preferably 51 to 96, more preferably 52 to 92, and particularly preferably 53 to 85. Within this range, the defoaming properties and surface finish are further improved.

[0029] Among the at least one hydrophobic substance (C) selected from the group consisting of hydrophobic silica, fatty acid metal salts, fatty acid amides, and waxes, the hydrophobic silica includes hydrophobic silica (hydrophobic wet silica, hydrophobic dry silica, etc.) obtained by subjecting silica (wet silica, dry silica, etc.) to a hydrophobic treatment with a hydrophobizing agent. Examples of the hydrophobizing agent include dimethylpolysiloxane and dichlorodimethylsilane.

[0030] The M value (methanol wettability) of the hydrophobic silica is preferably from 5 to 80, more preferably from 25 to 75, and particularly preferably from 40 to 70. Within this range, the defoaming property and surface finish are further improved.

[0031] The M value (methanol wettability) is a characteristic value that indicates the degree of hydrophobic treatment on the powder surface. A higher M value indicates lower hydrophilicity and a higher proportion of hydrophobic treatment (higher hydrophobicity). The M value is expressed as the volume fraction of the minimum amount of methanol required to uniformly disperse the powder (particles to be measured) in a water / methanol mixed solution, and can be determined by the following method.

[0032] <Method for Measuring the M Value> Water / methanol mixed solutions with varying methanol concentrations at 5% by volume intervals are prepared, and 5 ml of each solution is placed in a 10 ml test tube. 0.2 g of the measurement sample is then placed in the tube, which is then capped and inverted 20 times. After allowing to stand for 1-2 minutes, the contents are observed, and the M value is determined to be the methanol concentration (volume %) of the dispersion with the lowest methanol concentration among the dispersions in which there are no aggregates and the measurement sample is completely wetted and uniformly dispersed (it is customary not to specify the unit (volume %) for the M value).

[0033] The volume-based median diameter (d50; μm) of the hydrophobic wet silica is preferably 0.1 to 20, more preferably 1 to 10, and particularly preferably 6 to 7. Within this range, the defoaming property becomes even better.

[0034] The volume-based median diameter (d50) was measured using a laser diffraction particle size analyzer (e.g., Microtrac series from Leeds & Northrup, Partica LA series from Horiba, Ltd.) conforming to JIS Z8825:2022 (corresponding international standard; ISO13320:2020) by adding a measurement sample to 1,000 parts by weight of 2-propanol (purity of 99% by weight or more) so that the measurement sample concentration was 0.1% by weight to prepare a measurement dispersion, and measuring at a measurement temperature of 25±5°C. After that, the refractive index of 2-propanol was set to 1.3749, and the refractive index of the measurement sample was set to a literature value ("A GUIDE FOR ENTERING MICROTRAC" RUN The particle size is determined as a 50% cumulative volume average particle size using the "(F3) DATA" INFORMATION (produced by Leeds & Northrup).

[0035] The primary particle size (nm) of the hydrophobic dry silica is preferably 1 to 100, more preferably 5 to 60, and particularly preferably 7 to 16.

[0036] The primary particle diameter (nm) of the particles is the number-average circle-equivalent diameter calculated using image processing computer software (for example, WinRoof by Mitani Shoji Co., Ltd.) in accordance with JIS Z8901-2006 "Test powders and test particles," 5.4.4 Particle size distribution c) Microscopy, in which a sample prepared by the sprinkling method is observed under a transmission electron microscope at a magnification of 50,000 to 1,000,000 times, in accordance with JIS Z8827-1:2018 (corresponding international standard; ISO13322-1:2014) "Particle size - Image analysis - Part 1: Static image analysis."

[0037] Hydrophobic silica is readily available on the market, and examples thereof include the following commercial products: Examples of hydrophobic wet silica include the Nipsil SS series (SS-10, SS-50, SS-115, etc.); the Nipgel series (AY-200, AZ-400, BZ-400, CY-200, etc.) (Tosoh Silica Corporation; "Nipsil" and "NIPGEL" are registered Japanese trademarks of Tosoh Silica Corporation. The same applies to registered trademarks hereinafter.)); and the Sipernat D series (D10, D17, etc.) (Degussa Japan Co., Ltd.; "SIPERNAT" is a registered Japanese trademark of Evonik Degussa GmbH.)

[0038] Examples of hydrophobic dry silica include the Aerosil series (R972, RX200, RY200, R202, R805, and R812, etc.) (Nippon Aerosil Co., Ltd. and Evonik Degussa GmbH, "Aerosil" is a registered trademark of Evonik Degussa GmbH in Japan. The same applies to registered trademarks hereinafter.) and the Reolosil MT and DM series (MT-10, DM-10, DM-20S, etc.) (Tokuyama Corporation, "Reolosil" is a registered trademark of Tokuyama Corporation in Japan.)

[0039] Of the hydrophobic substances (C), fatty acid metal salts include salts of fatty acids having 12 to 22 carbon atoms with metals (such as alkaline earth metals, aluminum, manganese, cobalt, copper, iron, zinc, and nickel), and examples thereof include aluminum stearate, manganese stearate, cobalt stearate, copper stearate, iron stearate, nickel stearate, calcium stearate, zinc laurate, and magnesium behenate.

[0040] In the fatty acid metal salt, the amount of the metal and the fatty acid may be 1 to 3 moles (mono-, di-, or tri-form) of fatty acid per mole of metal, or a mixture of mono-, di-, and tri-forms may be used.

[0041] Of the hydrophobic substances (C), fatty acid amides include reaction products (fatty acid diamides) of alkylenediamines or alkenylenediamines having 1 to 6 carbon atoms with fatty acids having 10 to 22 carbon atoms, and / or reaction products (fatty acid monoamides) of alkylamines, alkenylamines or ammonia having 1 to 22 carbon atoms with fatty acids having 10 to 22 carbon atoms.

[0042] Examples of fatty acid diamides include ethylene bisstearylamide, ethylene bispalmitylamide, ethylene bismyristylamide, ethylene bislaurylamide, ethylene bisoleylamide, propylene bisstearylamide, propylene bispalmitylamide, propylene bismyristylamide, propylene bislaurylamide, propylene bisoleylamide, butylene bisstearylamide, butylene bispalmitylamide, butylene bismyristylamide, butylene bislaurylamide, butylene bisoleylamide, methylene bislaurylamide, methylene bisstearylamide, and hexamethylene bisstearylamide.

[0043] Examples of fatty acid monoamides include N-stearylstearylamide, oleic acid amide, erucic acid amide, and stearylamide.

[0044] Of the hydrophobic substances (C), examples of waxes include oxidized polyethylene wax, microcrystalline wax, paraffin wax, alcohol-modified wax, maleic acid-modified wax, ethylene-vinyl acetate copolymer wax, ethylene-acrylic acid copolymer wax, Fischer-Tropsch wax, Japan wax, beeswax, palm wax, carnauba wax, montan wax, and rice wax.

[0045] Of the hydrophobic substances (C), hydrophobic silica, fatty acid amides and waxes are preferred from the viewpoint of defoaming properties and surface finish, and hydrophobic silica is more preferred.

[0046] The content (wt %) of the hydrophobic substance (C) based on the weight of the liquid glycerin fatty acid ester (A) and the liquid alkylene oxide adduct (B) is preferably 0.1 to 15, more preferably 1 to 10, and particularly preferably 2.9 to 9.3. Within this range, the defoaming property and surface finish are further improved.

[0047] The dispersible defoaming agent of the present invention may contain a hydrophilic liquid (D) as needed. Examples of the hydrophilic liquid (D) include alkylene oxide adducts of active hydrogen compounds, fatty acid esters of alkylene oxide adducts of active hydrogen compounds, water, glycerin, and alkylene glycols having 2 to 4 carbon atoms.

[0048] In the alkylene oxide adduct of the active hydrogen compound in the hydrophilic liquid (D), the alkylene oxide is ethylene oxide and / or propylene oxide.

[0049] A plurality of types of alkylene oxides (oxyalkylene groups) may be contained, and when a plurality of types of alkylene oxides (oxyalkylene groups) are contained, they may be in a random form, a block form, or a mixture thereof.

[0050] In the alkylene oxide adduct of an active hydrogen compound in the hydrophilic liquid (D), the proportion (% by weight) of oxyethylene groups among the oxyalkylene groups constituting the alkylene oxide adduct is preferably 61 to 100 based on the weight of the oxyalkylene groups, and when oxyethylene and oxypropylene are contained, it is preferably 61 to 99, more preferably 65 to 90, and particularly preferably 69 to 82. Within this range, the defoaming properties and surface finish are further improved.

[0051] The number of moles (moles) of alkylene oxide added to the alkylene oxide adduct relative to 1 mole (equivalent) of active hydrogen of the active hydrogen compound is preferably 1 to 100, more preferably 2 to 75, and particularly preferably 5 to 60. Within this range, the defoaming properties and surface finish are further improved.

[0052] The active hydrogen compound is the same as the liquid alkylene oxide adduct (B), and among the active hydrogen compounds, alcohols and glycerides having a hydroxyl group are preferred from the viewpoints of defoaming properties and surface finish. That is, the hydrophilic liquid (D) is preferably at least one selected from the group consisting of alkylene oxide adducts of alcohols, alkylene oxide adducts of glycerides having a hydroxyl group, and fatty acid esters thereof.

[0053] Examples of fatty acids that can constitute the fatty acid ester of the alkylene oxide adduct of an active hydrogen compound include the above-mentioned monocarboxylic acids.

[0054] When the dispersible defoaming agent of the present invention contains a hydrophilic liquid (D), the content (wt%) of the hydrophilic liquid (D) is 1 × 10 based on the weight of the liquid glycerin fatty acid ester (A) and the liquid alkylene oxide adduct (B). －３ Preferably up to 30, more preferably 1 × 10 －１ The molecular weight is preferably 1 to 28, and more preferably 1 to 26. Within this range, the defoaming property and surface finish are further improved.

[0055] The dispersible defoaming agent of the present invention may contain other components (mineral oil, aliphatic alcohol, fatty acid, fatty acid ester, fatty acid amide, and / or modified silicone oil, etc.) within the range that does not impair the effects of the present invention, but it is preferable that the dispersible defoaming agent does not contain mineral oil and modified silicone oil.

[0056] The dispersible defoaming agent of the present invention may be produced by any method that can uniformly mix the liquid glycerin fatty acid ester (A), the liquid alkylene oxide adduct (B), at least one hydrophobic substance (C) selected from the group consisting of hydrophobic silica, fatty acid metal salts, fatty acid amides, and waxes, and, if necessary, the hydrophilic liquid (D) and / or other components, without any particular limitation, and any known mixing method or the like can be applied.

[0057] The hydrophobic substance (C), and the hydrophilic liquid (D) and / or other components contained as needed, may be contained in either the dispersoid containing the liquid glycerin fatty acid ester (A) or the dispersion medium containing the liquid alkylene oxide adduct (B), or may be contained in both the dispersoid and the dispersion medium.

[0058] The dispersed defoaming agent of the present invention is effective for aqueous resin solutions (usages, etc.) and aqueous resin emulsions (o / w resin emulsions, uses: water-based paints, water-based pressure-sensitive adhesives, paper coating agents, latex, etc.). Of these, it is particularly effective for aqueous resin emulsions. Examples of water-soluble resins for aqueous resin solutions include polyvinyl alcohol. Examples of resins for aqueous resin emulsions include acrylic resins, vinyl acetate resins, and nitrile rubber.

[0059] The amount of the antifoaming agent of the present invention to be used can be determined appropriately depending on the type of foaming liquid and the foaming state, for example, about 0.005 to 0.2% by weight based on the weight of the foaming liquid.

[0060] Hereinafter, unless otherwise specified, all parts mean parts by weight. Liquid alkylene oxide adducts (B) and hydrophilic liquids (D) for which no source of supply is specified were prepared by known methods (such as alkylene oxide addition reaction and esterification reaction).

[0061] Example 1 36.7 parts of a liquid alkylene oxide adduct (b1: a block adduct of decyl alcohol with ethylene oxide (13 mol) and propylene oxide (40 mol)) and 1.1 parts of a hydrophobic substance (c1: hydrophobic dry silica particles, Aerosil R972, Degussa Japan Co., Ltd., M value 43, number average primary particle size 16 nm) were uniformly mixed, and then 36.4 parts of a liquid alkylene oxide adduct (b2: a block adduct of glycerin with propylene oxide (40 mol) and ethylene oxide (14 mol)), and 1.1 parts of a hydrophilic liquid (d1: water) were added and mixed uniformly to prepare 75.3 parts of a dispersion medium (1).

[0062] Meanwhile, 26.9 parts of a liquid glycerin fatty acid ester (a1: rapeseed oil, Okamura Oil Mills, Ltd.) and 5.4 parts of a hydrophobic substance (c2: NIPSIL SS-215, Tosoh Silica Corporation, hydrophobic wet silica particles, M value 65, volume-based median diameter 6 μm) were uniformly mixed and homogenized using a pressure homogenizer (SMT Corporation) at 3500 psi (24.1 MPa) to obtain 32.3 parts of dispersoid (1).

[0063] 75.3 parts of the dispersion medium (1) and 32.3 parts of the dispersoid (1) were uniformly mixed to obtain a dispersed defoaming agent (1) of the present invention.

[0064] It was confirmed that the defoaming agent was a dispersion containing a dispersoid consisting of a liquid glycerin fatty acid ester (A) and a dispersion medium consisting of a liquid alkylene oxide adduct (B) by <1> observing the phase state using a phase contrast microscope and <2> determining the dispersion medium (continuous phase) and the dispersoid (discontinuous layer) by measuring electrical conductivity.

[0065] <1> A small amount of the evaluation material (dispersed defoaming agent) was attached to a slide glass, and a cover glass was placed on top to prepare a preparation. The phase state of the measurement sample was observed at a magnification of 200 times using a phase contrast microscope (Olympus BX60F5, Olympus Corporation, "Olympus" is a registered trademark of the company in Japan) (observations were made in the same way for other Examples). As shown in Fig. 1, the dispersion medium (continuous phase) and dispersoid (discontinuous layer) were observed for the dispersed defoaming agent (1) obtained in Example 1, and it was confirmed that the dispersed defoaming agent was composed of at least two phases.

[0066] <2> It is known that when measuring the electrical conductivity of a mixture containing two or more liquid phases, the electrical conductivity is the value of the electrical conductivity of the dispersion medium (continuous phase) (there is almost no effect of the hydrophobic substance (c)) (for example, "Introductory Lecture: Emulsions and HLB", Oleoscience, Vol. 1, No. 2, 2001, by Hironobu Kunieda and Kenji Aramaki, published by the Japan Oil Chemists' Society; "The Science of Emulsions (II)", Cooking Science, Vol. 6, No. 4, 1973, by Tetsuya Hanai, published by the Japan Cooking Science Society). Therefore, the electrical conductivity was measured using a conductivity meter (DT-700, Dispersion Technology, Inc.) (average value of 50 measurements; similar measurements were also taken for other Examples). The electrical conductivity of the dispersed defoaming agent (1) of Example 1 was 9.7 × 10 －７ It was S / m.

[0067] The electrical conductivity of "dispersoid (1) consisting of 26.9 parts of liquid glycerin fatty acid ester (a1) and 5.4 parts of hydrophobic substance (c2)" is 3.8 × 10 －１１The electrical conductivity of "dispersion medium (1) consisting of 36.7 parts of liquid alkylene oxide adduct (b1), 1.1 parts of hydrophobic substance (c1), 36.4 parts of liquid alkylene oxide adduct (b2), and 1.1 parts of hydrophilic liquid (d1: water)" was 1.1 × 10 －６ It was S / m.

[0068] Therefore, it was found that the dispersion defoaming agent (1) of Example 1 had a dispersion medium (continuous phase) composed of the liquid alkylene oxide adduct (b1), the liquid alkylene oxide adduct (b2), the hydrophobic substance (c1), and the aqueous liquid (d1), and a dispersoid (discontinuous layer) composed of the liquid glycerin fatty acid ester (a1) and the hydrophobic substance (c2).

[0069] Example 2 57.1 parts of a liquid alkylene oxide adduct (b3: polypropylene glycol having a number average molecular weight of 1000, Primepol PX-1000, Sanyo Chemical Industries, Ltd.; "Primepol" is a registered trademark of the company in Japan), 3.7 parts of a hydrophilic liquid (d1), 1.2 parts of a hydrophilic liquid (d2: polyethylene glycol, number average molecular weight Mn 200, PEG-200, Sanyo Chemical Industries, Ltd.), and 9.2 parts of a hydrophilic liquid (d3: an ethylene oxide (10 mol) adduct of castor oil, Braunon BR-410, Aoki Oil & Fats Co., Ltd.; "Braunon" is a registered trademark of the company in Japan) were uniformly mixed to prepare 71.2 parts of a dispersion medium (2).

[0070] 71.2 parts of the dispersion medium (2) and 51.5 parts of the dispersoid (1) prepared in the same manner as in Example 1 {42.9 parts of the liquid glycerin fatty acid ester (a1) and 8.6 parts of the hydrophobic substance (c2)} were uniformly mixed to obtain a dispersed defoaming agent (2) of the present invention.

[0071] <1> When the phase state of the dispersed defoaming agent (2) obtained in Example 2 was observed with a phase contrast microscope, it was confirmed that the dispersed defoaming agent was composed of at least two phases.

[0072] <2> The electrical conductivity of the dispersed defoaming agent (2) obtained in Example 2 was 8.8 × 10 －７ The electrical conductivity of the "dispersoid (1) consisting of 42.9 parts of liquid glycerin fatty acid ester (a1) and 8.6 parts of hydrophobic substance (c2)" was 3.8 × 10－１１ The electrical conductivity of "dispersion medium (2) consisting of 57.1 parts of liquid alkylene oxide adduct (b3), 3.7 parts of hydrophilic liquid (d1), 1.2 parts of hydrophilic liquid (d2), and 9.2 parts of hydrophilic liquid (d3)" was 2.6 × 10 －６ It was S / m.

[0073] Therefore, it was found that the dispersion defoaming agent (2) of Example 2 had a dispersion medium (continuous phase) composed of the liquid alkylene oxide adduct (b3), the aqueous liquid (d1), the hydrophilic liquid (d1), the hydrophilic liquid (d2) and the hydrophilic liquid (d3), and a dispersoid (discontinuous layer) composed of the liquid glycerin fatty acid ester (a1) and the hydrophobic substance (c2).

[0074] Example 3 79.1 parts of a dispersion medium (3) were prepared by uniformly mixing 1.0 part of a liquid alkylene oxide adduct (b10: polyoxyethylene polyoxypropylene polyoxyethylene block polymer, the number average molecular weight of the polyoxypropylene chain portion is approximately 1750, the total number average molecular weight is 2000, NEWPOL PE-61, Sanyo Chemical Industries, Ltd.; "NEWPOL" is a registered Japanese trademark of this company. The same applies to registered trademarks hereinafter), 1.0 part of a liquid alkylene oxide adduct (b11: a propylene oxide (5 mol) adduct of butanol, NEWPOL LB-65, Sanyo Chemical Industries, Ltd.), and 77.1 parts of a liquid alkylene oxide adduct (b12: polyoxyethylene polyoxypropylene polyoxyethylene block polymer, the number average molecular weight of the polyoxypropylene chain portion is approximately 1750, the total number average molecular weight is 2400, NEWPOL PE-62, Sanyo Chemical Industries, Ltd.).

[0075] 79.1 parts of the dispersion medium (3) and 25.1 parts of the dispersoid (1) prepared in the same manner as in Example 1 {20.9 parts of a liquid glycerin fatty acid ester (a1) and 4.2 parts of a hydrophobic substance (c2)} were uniformly mixed to obtain a dispersed defoaming agent (3) of the present invention.

[0076] <1> When the phase state of the dispersed defoaming agent (3) obtained in Example 3 was observed with a phase contrast microscope, it was confirmed that the dispersed defoaming agent was composed of at least two phases.

[0077] <2> The electrical conductivity of the dispersed defoaming agent (3) obtained in Example 3 was 3.4 × 10 －８ The electrical conductivity of the "dispersoid (1) consisting of 20.9 parts of liquid glycerin fatty acid ester (a1) and 4.2 parts of hydrophobic substance (c2)" was 3.8 × 10 －１１ The electrical conductivity of "dispersion medium (3) consisting of 1.0 part of liquid alkylene oxide adduct (b10), 1.0 part of liquid alkylene oxide adduct (b11), and 77.1 parts of liquid alkylene oxide adduct (b12)" was 3.7 × 10 －８ It was S / m.

[0078] Therefore, it was found that the dispersion defoaming agent (3) of Example 3 had a dispersion medium (continuous phase) composed of the liquid alkylene oxide adduct (b10), the liquid alkylene oxide adduct (b11) and the liquid alkylene oxide adduct (b12), and a dispersoid (discontinuous layer) composed of the liquid glycerin fatty acid ester (a1) and the hydrophobic substance (c2).

[0079] Example 4 61.3 parts of the liquid alkylene oxide adduct (b12) and 1.1 parts of a liquid alkylene oxide adduct (b13: a propylene oxide (40 mol) adduct of butanol, Newpol LB-1715, Sanyo Chemical Industries, Ltd.) were uniformly mixed to prepare 62.4 parts of a dispersion medium (4).

[0080] 62.4 parts of the dispersion medium (4) and 45.1 parts of the dispersoid (1) prepared in the same manner as in Example 1 {37.6 parts of liquid glycerin fatty acid ester (a1) and 7.5 parts of hydrophobic substance (c2)} were uniformly mixed to obtain a dispersed defoaming agent (4) of the present invention.

[0081] <1> When the phase state of the dispersed defoaming agent (4) obtained in Example 4 was observed with a phase contrast microscope, it was confirmed that the dispersed defoaming agent was composed of at least two phases.

[0082] <2> The electrical conductivity of the dispersed defoaming agent (4) obtained in Example 4 was 3.1 × 10 －８ The electrical conductivity of the "dispersoid (1) consisting of 37.6 parts of liquid glycerin fatty acid ester (a1) and 7.5 parts of hydrophobic substance (c2)" was 3.8 × 10 －１１The electrical conductivity of "dispersion medium (4) consisting of 61.3 parts of liquid alkylene oxide adduct (b12) and 1.1 parts of liquid alkylene oxide adduct (b13)" was 3.2 × 10 －８ It was S / m.

[0083] Therefore, it was found that the dispersion defoaming agent (4) of Example 4 had a dispersion medium (continuous phase) composed of the liquid alkylene oxide adduct (b12) and the liquid alkylene oxide adduct (b13), and a dispersoid (discontinuous layer) composed of the liquid glycerin fatty acid ester (a1) and the hydrophobic substance (c2).

[0084] Example 5 37.6 parts of a liquid glycerin fatty acid ester (a2: cottonseed oil, Okamura Oil Mills, Ltd.) and 7.5 parts of a hydrophobic substance (c1) were uniformly mixed and homogenized using a pressure homogenizer (SMT Corporation) at 3500 psi (24.1 MPa) to obtain 45.1 parts of a dispersoid (5).

[0085] 62.4 parts of the dispersion medium (5; liquid alkylene oxide adduct (b2)) and 45.1 parts of the dispersoid (5) were uniformly mixed to obtain a dispersed defoaming agent (5) of the present invention.

[0086] <1> When the phase state of the dispersed defoaming agent (5) obtained in Example 5 was observed with a phase contrast microscope, it was confirmed that the dispersed defoaming agent had at least two phases.

[0087] <2> The electrical conductivity of the dispersed defoaming agent (5) obtained in Example 5 was 2.3 × 10 －８ The electrical conductivity of the "dispersoid (5) consisting of 37.6 parts of liquid glycerin fatty acid ester (a2) and 7.5 parts of hydrophobic substance (c1)" was 5.8 × 10 －１１ The electrical conductivity of the "dispersion medium (5) consisting of 62.4 parts of liquid alkylene oxide adduct (b2)" was 2.5 × 10 －８ It was S / m.

[0088] Therefore, it was found that in the dispersed defoaming agent (5) of Example 5, the dispersion medium (continuous phase) was composed of the liquid alkylene oxide adduct (b2), and the dispersoid (discontinuous layer) was composed of the liquid glycerin fatty acid ester (a2) and the hydrophobic substance (c1).

[0089] Example 6 67.4 parts of a liquid alkylene oxide adduct (b3), 0.6 parts of a liquid alkylene oxide adduct (b4: a block adduct of glycerin with ethylene oxide (3 moles) and 2-ethylhexyl glycidyl ether (2 moles)), 2.9 parts of a hydrophilic liquid (d1), 1.2 parts of a hydrophilic liquid (d2), 8.7 parts of a hydrophilic liquid (d3), and 0.6 parts of a hydrophilic liquid (d5: glycerin, RG, NOF Corporation) were uniformly mixed to prepare 81.4 parts of a dispersion medium (6).

[0090] Separately, 14.5 parts of the liquid glycerin fatty acid ester (a1) and 2.9 parts of a hydrophobic substance (c3: Alflow H-50S, NOF Corporation, ethylene bisstearylamide, softening point 143°C, "Alflow" is a registered Japanese trademark of NOF Corporation) were heated to 145°C with stirring, and heating and stirring were continued at this temperature for an additional 15 minutes. This was then added with stirring to 17.5 parts of the liquid glycerin fatty acid ester (a1) that had been cooled to 25°C or below, and the mixture was homogenized at 3500 psi (24.1 MPa) using a pressure homogenizer (SMT Corporation) to obtain 34.9 parts of dispersoids (6).

[0091] 81.4 parts of the dispersion medium (6) and 34.9 parts of the dispersoid (6) were uniformly mixed to obtain a dispersed defoaming agent (6) of the present invention.

[0092] <1> When the phase state of the dispersed defoaming agent (6) obtained in Example 6 was observed with a phase contrast microscope, it was confirmed that the dispersed defoaming agent was composed of at least two phases.

[0093] <2> The electrical conductivity of the dispersed defoaming agent (6) obtained in Example 6 was 9.0 × 10 －７ The electrical conductivity of the "dispersoid (6) consisting of 32.0 parts of liquid glycerin fatty acid ester (a1) and 2.9 parts of hydrophobic substance (c3)" was 3.9 × 10 －１１ The electrical conductivity of "dispersion medium (6) consisting of 67.4 parts of liquid alkylene oxide adduct (b3), 0.6 parts of liquid alkylene oxide adduct (b4), 2.9 parts of hydrophilic liquid (d1), 1.2 parts of hydrophilic liquid (d2), 8.7 parts of hydrophilic liquid (d3), and 0.6 parts of hydrophilic liquid (d5)" was 9.8 × 10 －７ It was S / m.

[0094] Therefore, it was found that the dispersion defoaming agent (6) of Example 6 had a dispersion medium (continuous phase) composed of the liquid alkylene oxide adduct (b3), the liquid alkylene oxide adduct (b4), the hydrophilic liquid (d1), the hydrophilic liquid (d2), the hydrophilic liquid (d3) and the hydrophilic liquid (d5), and a dispersoid (discontinuous layer) composed of the liquid glycerin fatty acid ester (a1) and the hydrophobic substance (c3).

[0095] Example 7 11.0 parts of liquid alkylene oxide adduct (b1), 53.3 parts of liquid alkylene oxide adduct (b2), 53.3 parts of liquid alkylene oxide adduct (b5: polypropylene glycol having a number average molecular weight of 1,140, ​​Sannix PP-1200, Sanyo Chemical Industries, Ltd., and "SANNIX" is a registered Japanese trademark of the company. The same applies hereinafter to registered trademarks.), 8.2 parts of a liquid alkylene oxide adduct (b6: a propylene oxide (43 mol) adduct of glycerin, SANNIX GP-3000, Sanyo Chemical Industries, Ltd.), 5.5 parts of a hydrophilic liquid (d1), 2.2 parts of a hydrophilic liquid (d4: diethylene glycol, Nippon Shokubai Co., Ltd.), 2.2 parts of a hydrophilic liquid (d6: polyoxyethylene sorbitan oleate, EMASOL O-120V, Kao Corporation, and "EMASOL" is a registered Japanese trademark of the company), and 0.5 parts of a hydrophilic liquid (d7: an ethylene oxide (2 mol), propylene oxide (2 mol), and ethylene oxide (4 mol) block adduct of pentadecanol) were uniformly mixed to obtain 83.4 parts of a dispersion medium (7).

[0096] On the other hand, 22.0 parts of a liquid glycerin fatty acid ester (a3: rice bran oil, Okamura Oil Mills, Ltd.) and 4.4 parts of a hydrophobic substance (c1) were uniformly mixed and homogenized using a pressure homogenizer (SMT Corporation) at 3500 psi (24.1 MPa) to obtain 26.4 parts of a dispersoid (7).

[0097] 83.4 parts of the dispersion medium (7) and 26.4 parts of the dispersoid (7) were uniformly mixed to obtain a dispersed defoaming agent (7) of the present invention.

[0098] <1> When the phase state of the dispersed defoaming agent (7) obtained in Example 7 was observed with a phase contrast microscope, it was confirmed that the dispersed defoaming agent had at least two phases.

[0099] <2> The electrical conductivity of the dispersed defoaming agent (7) obtained in Example 7 was 8.8 × 10 －７ The electrical conductivity of the "dispersoid (7) consisting of 22.0 parts of liquid glycerin fatty acid ester (a3) ​​and 4.4 parts of hydrophobic substance (c1)" was 4.4 × 10 －１１ The electrical conductivity of "dispersion medium (7) consisting of 11.0 parts of liquid alkylene oxide adduct (b1), 53.3 parts of liquid alkylene oxide adduct (b2), 8.2 parts of liquid alkylene oxide adduct (b5), 5.5 parts of liquid alkylene oxide adduct (b6), 2.2 parts of hydrophilic liquid (d1), 2.2 parts of hydrophilic liquid (d4), 0.5 parts of hydrophilic liquid (d6), and 0.5 parts of hydrophilic liquid (d7)" was 9.5 × 10 －７ It was S / m.

[0100] Therefore, it was found that the dispersion defoaming agent (7) of Example 7 had a dispersion medium (continuous phase) composed of the liquid alkylene oxide adduct (b1), the liquid alkylene oxide adduct (b2), the liquid alkylene oxide adduct (b5), the liquid alkylene oxide adduct (b6), the hydrophilic liquid (d1), the hydrophilic liquid (d4), the hydrophilic liquid (d6) and the hydrophilic liquid (d7), and a dispersoid (discontinuous layer) composed of the liquid glycerin fatty acid ester (a3) ​​and the hydrophobic substance (c1).

[0101] Example 8 62.4 parts of a liquid alkylene oxide adduct (b3), 4.6 parts of a liquid alkylene oxide adduct (b7: polypropylene glycol having a number average molecular weight of 200, Sannix PP-200, Sanyo Chemical Industries, Ltd.), 0.6 parts of a liquid alkylene oxide adduct (b8: polypropylene glycol having a number average molecular weight of 3200, Sannix PP-3000, Sanyo Chemical Industries, Ltd.), 0.6 parts of a liquid alkylene oxide adduct (b9: a propylene oxide (86 mol) ethylene oxide (5) block adduct of glycerin), 2.9 parts of a hydrophilic liquid (d1), 1.2 parts of a hydrophilic liquid (d2), and 8.7 parts of a hydrophilic liquid (d3) were uniformly mixed to obtain 81.0 parts of a dispersion medium (8).

[0102] Separately, 14.5 parts of the liquid glycerin fatty acid ester (a2) and 2.9 parts of a hydrophobic substance (c4: Hi-Mic-1070, Nippon Seiro Co., Ltd., microcrystalline wax, softening point 80°C, "Hi-Mic" is a registered Japanese trademark of Nippon Seiro Co., Ltd.) were heated to 145°C with stirring, and heating and stirring were continued at this temperature for an additional 15 minutes. After that, this was added with stirring to 17.3 parts of the liquid glycerin fatty acid ester (a2) that had been cooled to 25°C or below, and then homogenized at 3500 psi (24.1 MPa) using a pressure homogenizer (SMT Corporation) to obtain 34.7 parts of dispersoids (8).

[0103] 81.0 parts of the dispersion medium (8) and 34.7 parts of the dispersoid (8) were uniformly mixed to obtain a dispersed defoaming agent (8) of the present invention.

[0104] <1> When the phase state of the dispersed defoaming agent (8) obtained in Example 8 was observed with a phase contrast microscope, it was confirmed that the dispersed defoaming agent was composed of at least two phases.

[0105] <2> The electrical conductivity of the dispersed defoaming agent (8) obtained in Example 8 was 8.3 × 10 －７ The electrical conductivity of the "dispersoid (8) consisting of 31.8 parts of liquid glycerin fatty acid ester (a2) and 2.9 parts of hydrophobic substance (c4)" was 2.7 × 10 －１１ The electrical conductivity of "dispersion medium (8) consisting of 62.4 parts of liquid alkylene oxide adduct (b3), 4.6 parts of liquid alkylene oxide adduct (b7), 0.6 parts of liquid alkylene oxide adduct (b8), 0.6 parts of liquid alkylene oxide adduct (b9), 2.9 parts of hydrophilic liquid (d1), 1.2 parts of hydrophilic liquid (d2), and 8.7 parts of hydrophilic liquid (d3)" was 8.9 × 10 －７ It was S / m.

[0106] Therefore, it was found that the dispersed defoaming agent (8) of Example 8 had a dispersion medium (continuous phase) composed of the liquid alkylene oxide adduct (b3), the liquid alkylene oxide adduct (b7), the liquid alkylene oxide adduct (b8), the liquid alkylene oxide adduct (b9), the hydrophilic liquid (d1), the hydrophilic liquid (d2) and the hydrophilic liquid (d3), and a dispersoid (discontinuous layer) composed of the liquid glycerin fatty acid ester (a2) and the hydrophobic substance (c4).

[0107] Example 9 65.9 parts of a liquid alkylene oxide adduct (b12), 1.1 parts of a liquid alkylene oxide adduct (b14: oleate ester of a butanol propylene oxide (25 mol) adduct), and 1.1 parts of a liquid alkylene oxide adduct (b15: oleate ester of a castor oil propylene oxide (30 mol) adduct) were uniformly mixed to obtain 68.1 parts of a dispersion medium (9).

[0108] 68.1 parts of the dispersion medium (9) and 38.3 parts of a dispersoid (5) prepared in the same manner as in Example 5 {31.9 parts of a liquid glycerin fatty acid ester (a2) and 6.4 parts of a hydrophobic substance (c1)} were uniformly mixed to obtain a dispersed defoaming agent (9) of the present invention.

[0109] <1> When the phase state of the dispersed defoaming agent (9) obtained in Example 9 was observed with a phase contrast microscope, it was confirmed that the dispersed defoaming agent had at least two phases.

[0110] <2> The electrical conductivity of the dispersed defoaming agent (9) obtained in Example 9 was 4.0 × 10 －８ The electrical conductivity of the "dispersoid (5) consisting of 31.9 parts of liquid glycerin fatty acid ester (a2) and 6.4 parts of hydrophobic substance (c1)" was 5.8 × 10 －１１ The electrical conductivity of "dispersion medium (8) consisting of 65.9 parts of liquid alkylene oxide adduct (b12), 1.1 parts of liquid alkylene oxide adduct (b14), and 1.1 parts of liquid alkylene oxide adduct (b15)" was 4.4 × 10 －８ It was S / m.

[0111] Therefore, it was found that the dispersion defoaming agent (9) of Example 9 had a dispersion medium (continuous phase) composed of the liquid alkylene oxide adduct (b12), the liquid alkylene oxide adduct (b14) and the liquid alkylene oxide adduct (b15), and a dispersoid (discontinuous layer) composed of the liquid glycerin fatty acid ester (a2) and the hydrophobic substance (c1).

[0112] Example 10 3.1 parts of a liquid glycerin fatty acid ester (a4: palm olein oil, Okamura Oil Mills, Ltd.) and 0.6 parts of a hydrophobic substance (c1) were uniformly mixed and homogenized at 3500 psi (24.1 MPa) using a pressure homogenizer (SMT Corporation). This mixture was then uniformly mixed with 14.9 parts of a dispersoid (7) prepared in the same manner as in Example 7 (12.4 parts of a liquid glycerin fatty acid ester (a3) ​​and 2.5 parts of a hydrophobic substance (c1)), to obtain 18.6 parts of a dispersoid (10).

[0113] 84.5 parts of the dispersion medium (10; liquid alkylene oxide adduct (b12)) and 18.6 parts of the dispersoid (10) were uniformly mixed to obtain a dispersed defoaming agent (10) of the present invention.

[0114] <1> When the phase state of the dispersed defoaming agent (10) obtained in Example 10 was observed with a phase contrast microscope, it was confirmed that the dispersed defoaming agent was composed of at least two phases.

[0115] <2> The electrical conductivity of the dispersed defoaming agent (10) obtained in Example 10 was 2.6 × 10 －８ The electrical conductivity of "dispersoid (10) consisting of 12.4 parts of liquid glycerin fatty acid ester (a3), 3.1 parts of liquid glycerin fatty acid ester (a4), and 3.1 parts of hydrophobic substance (c1)" was 3.5 × 10 －１１ The electrical conductivity of the "dispersion medium (10) composed of 84.5 parts of liquid alkylene oxide adduct (b12)" was 3.0 × 10 －８ It was S / m.

[0116] Therefore, it was found that in the dispersed defoaming agent (10) of Example 10, the dispersion medium (continuous phase) was composed of the liquid alkylene oxide adduct (b12), and the dispersoid (discontinuous layer) was composed of the liquid glycerin fatty acid ester (a3), the liquid glycerin fatty acid ester (a4), and the hydrophobic substance (c1).

[0117] Example 11 53.3 parts of a liquid alkylene oxide adduct (b3), 3.4 parts of a hydrophilic liquid (d1), 1.3 parts of a hydrophilic liquid (d2), 20.2 parts of a hydrophilic liquid (d3), and 0.7 parts of a hydrophilic liquid (d8: a block adduct of pentadecanol with ethylene oxide (2 mol), propylene oxide (2 mol), and ethylene oxide (10 mol)) were uniformly mixed to obtain 78.9 parts of a dispersion medium (11).

[0118] 78.9 parts of the dispersion medium (11) and 56.0 parts of a dispersoid (5) prepared in the same manner as in Example 5 {46.7 parts of a liquid glycerin fatty acid ester (a2) and 9.3 parts of a hydrophobic substance (c1)} were uniformly mixed to obtain a dispersed defoaming agent (11) of the present invention.

[0119] <1> When the phase state of the dispersed defoaming agent (11) obtained in Example 11 was observed with a phase contrast microscope, it was confirmed that the dispersed defoaming agent was composed of at least two phases.

[0120] <2> The electrical conductivity of the dispersed defoaming agent (11) obtained in Example 11 was 9.1 × 10 －７ The electrical conductivity of the "dispersoid (5) consisting of 46.7 parts of liquid glycerin fatty acid ester (a2) and 9.3 parts of hydrophobic substance (c1)" was 5.8 × 10 －１１ The electrical conductivity of "dispersion medium (11) consisting of 53.3 parts of liquid alkylene oxide adduct (b3), 3.4 parts of hydrophilic liquid (d1), 1.3 parts of hydrophilic liquid (d2), 20.2 parts of hydrophilic liquid (d3), and 0.7 parts of hydrophilic liquid (d8)" was 2.2 × 10 －６ It was S / m.

[0121] Therefore, it was found that the dispersed defoaming agent (11) of Example 11 had a dispersion medium (continuous phase) composed of the liquid alkylene oxide adduct (b3), the hydrophilic liquid (d1), the hydrophilic liquid (d2), the hydrophilic liquid (d3) and the hydrophilic liquid (d8), and a dispersoid (discontinuous layer) composed of the liquid glycerin fatty acid ester (a2) and the hydrophobic substance (c1).

[0122] <Comparative Example> Based on the description of Example 1 of Patent Document 1, 25 parts of soybean oil (The Nisshin Oillio Group, Ltd.), 74 parts of sorbitan trioleate (Nonion OP-85R, NOF Corporation), and 1 part of polyoxyethylene (20 mol) sorbitan monooleate (Willsurf TF-80, NOF Corporation; "Willsurf" is a registered trademark of the company in Japan) were uniformly mixed at 80°C and then cooled to about 25°C, thereby obtaining a comparative defoaming agent (H).

[0123] <Evaluation of Defoaming Property> 90 g of an acrylic styrene resin emulsion (BASF Japan Ltd., ACRONAL 295DN; "ACRONAL" is a registered trademark of BASF Societas Europea in Japan) and 10 g of ion-exchanged water were uniformly stirred and mixed to prepare a mixture, and then this mixture and 30 μL of an evaluation sample (any of the dispersed defoamers (1) to (11) prepared in Examples 1 to 11 or the defoamer (H) prepared in the Comparative Example) were stirred for 5 minutes in a stand automixer DL-7524 (Kai Corporation, speed adjustment lever 10) to prepare an aqueous resin emulsion. After stirring, the aqueous resin emulsion was transferred to a 300 mL measuring cylinder, and the weight (g) and volume (ml) were measured 8 seconds after stirring was stopped, and the specific gravity was calculated and shown in the table below. A higher specific gravity indicates higher defoaming property, and is therefore preferable. Furthermore, the specific gravity (blank) was calculated in the same manner as above, except that no antifoaming agent was added, and is shown in the table below.

[0124] <Evaluation of Surface Finish> After evaluating the defoaming properties, the aqueous resin emulsion was applied to a glass plate using a 3 mil film applicator (FAs-2876, Coating Star Co., Ltd.), and the coated surface was visually evaluated for cissing and traces of broken bubbles. The evaluation results for cissing and traces of broken bubbles are shown in the table below.

[0125]

[0126] As described above, the defoaming agent of the present invention was superior to the comparative defoaming agent in defoaming properties while maintaining the surface finish.

Claims

1. A dispersed defoaming agent comprising: a dispersoid comprising a liquid glycerin fatty acid ester (A); a dispersion medium comprising a liquid alkylene oxide adduct (B); and at least one hydrophobic substance (C) selected from the group consisting of hydrophobic silica, fatty acid metal salts, fatty acid amides, and waxes, wherein the content of the liquid glycerin fatty acid ester (A) is 4 to 49% by weight, the content of the liquid alkylene oxide adduct (B) is 51 to 96% by weight, and the content of the hydrophobic substance (C) is 0.1 to 15% by weight, based on the weights of the liquid glycerin fatty acid ester (A) and the liquid alkylene oxide adduct (B).

2. Further comprising a hydrophilic liquid (D), wherein the content of the hydrophilic liquid (D) is 1 x 10 based on the weight of the liquid glycerin fatty acid ester (A) and the liquid alkylene oxide adduct (B). －３ 2. The dispersed defoaming agent according to claim 1, wherein the content is from 100 to 30% by weight.

3. The dispersible defoaming agent according to claim 1, wherein the liquid alkylene oxide adduct (B) is at least one selected from the group consisting of alkylene oxide adducts of alcohols, alkylene oxide adducts of glycerides having a hydroxyl group, and fatty acid esters thereof, the alkylene oxide is at least one selected from the group consisting of ethylene oxide, propylene oxide, and alkyl glycidyl ether, and the proportion of oxyethylene groups among the oxyalkylene groups constituting the alkylene oxide adduct is 0 to 60% by weight.

4. The dispersible defoaming agent according to claim 2, wherein the hydrophilic liquid (D) is at least one selected from the group consisting of alkylene oxide adducts of alcohols, alkylene oxide adducts of glycerides having hydroxyl groups, fatty acid esters thereof, water, glycerin, and alkylene glycols having 2 to 4 carbon atoms, the alkylene oxide being at least one selected from the group consisting of ethylene oxide and propylene oxide, and the proportion of oxyethylene groups among the oxyalkylene groups constituting the alkylene oxide adduct is 61 to 100% by weight.

5. A water-based resin emulsion comprising the dispersed defoaming agent according to any one of claims 1 to 4, water, and a resin.

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