JP6248806B2 - Method for producing antifoam oil compound and method for producing antifoam composition - Google Patents

Description

The present invention provides a method for producing an antifoaming oil compound that provides a silicone-based antifoaming agent composition having excellent initial antifoaming properties and antifoaming durability even in foaming liquids, particularly alkaline foaming liquids, and this method. The present invention relates to a method for producing an antifoaming composition containing an oil compound.

  Silicone antifoaming agents are widely used in processes involving foaming in the chemical industry, food industry, petroleum industry, paper industry, textile industry, pharmaceutical industry, etc., and include dimethylpolysiloxane, methylphenylpolysiloxane, and methylvinylpolysiloxane. An oil compound type antifoaming agent in which a silicone oil such as the above is mixed with fine powder silica has been widely used.

  In actual use, an emulsion type antifoaming agent in which the oil compound type antifoaming agent is dispersed in water together with a surfactant, or an organopolysiloxane modified with a polyoxyalkylene group and an oil compound are used in combination. Self-emulsifying antifoaming agents and the like have been proposed (Patent Document 1: Japanese Patent Laid-Open No. 51-71886, Patent Document 2: Japanese Patent Publication No. 54-43015, Patent Document 3: Japanese Patent Publication No. 52-19836). Gazette, patent document 4: Japanese Patent Publication No. 52-22638, patent document 5: Japanese Patent Publication No. 55-23084), and the defoaming performance of the oil compound-type antifoaming agent as a raw material is large. Defoaming performance may be insufficient. As an example, problems such as insufficient initial defoaming performance and deterioration of the defoaming performance over time due to prolonged contact with the foaming liquid may occur, which is particularly noticeable when the foaming liquid is alkaline. there were.

  Various proposals have been made to improve these problems and to further improve the defoaming performance. For example, a method of hydrophobizing silica used in an oil compound with chlorosilane or the like in advance (Patent Document 6: JP-B 52-52). No. 31836), a method of treating silica with a nitrogen-containing organosilicon compound (Patent Document 7: Japanese Patent Publication No. 51-35556) and the like. There has been a demand for further improvement in performance.

  Recently, in response to these problems, a self-emulsification type antifoaming agent composition having improved alkali resistance by mixing hydrophobic organopolysiloxane and fine powder silica surface-treated with organopolysiloxane in the presence of an alkaline catalyst. (Patent Document 8: Japanese Patent No. 4232031), emulsion type antifoaming composition (Patent Document 9: Japanese Patent Application Laid-Open No. 2007-222812) and the like have been proposed.

JP-A-51-71886 Japanese Patent Publication No.54-43015 Japanese Patent Publication No.52-19836 Japanese Patent Publication No. 52-22638 Japanese Patent Publication No. 55-23084 Japanese Patent Publication No.52-31836 Japanese Patent Publication No. 51-35556 Japanese Patent No. 4232031 JP 2007-222812 A

The present invention has been made in view of the above circumstances, and an economical production method of an oil compound having excellent initial defoaming property and less deterioration over time even in a foaming liquid, particularly an alkaline foaming liquid, and an excellent defoaming performance, and this It aims at providing the manufacturing method of the antifoamer composition containing an oil compound.

As a result of intensive studies to achieve the above object, the present inventors
(A) Essentially hydrophobic organopolysiloxane having a viscosity at 25 ° C. of 10 to 100,000 mm ² / s: 100 parts by mass
(B) Fine powdered silica having a specific surface area of 50 m ² / g or more: When compounding 1 to 30 parts by mass,
(C) Trifunctional hydrolyzable silane represented by the following general formula (I) and / or a partial hydrolysis condensate thereof: 0.001 to 5 parts by mass,
R ¹ (R ² O) ₃ Si (I)
(In the formula, R ¹ is a monovalent organic group having 1 to 20 carbon atoms, R ² may be the same or different, and is a hydrogen atom or a substituted or unsubstituted, saturated or unsaturated carbon number. Is a monovalent hydrocarbon group of 1 to 20.)
(D) Water: first step of kneading 0 to 5 parts by mass,
A second step of heat-treating the kneaded product obtained in the first step,
In the kneaded material obtained in this second step,
(E) Alkali catalyst or acid catalyst: third step of kneading 0.001 to 5 parts by mass;
A fourth step of heat treating the kneaded product obtained in the third step,
By using the oil compound for antifoaming agent produced by the fifth step of kneading acid or alkali as a neutralizing agent in the kneaded product obtained in the fourth step, the initial defoaming is also performed in the alkaline foaming liquid. The present inventors have found that a silicone-based antifoaming agent composition having excellent properties and particularly antifoaming sustainability can be obtained, and have led to the present invention.

Therefore, this invention provides the manufacturing method of the antifoaming oil compound shown below, and the manufacturing method of the antifoamer composition containing the same .
[1]
(1) (A) Essentially hydrophobic organopolysiloxane having a viscosity at 25 ° C. of 10 to 100,000 mm ² / s: 100 parts by mass
(B) Fine powder silica having a specific surface area of 50 m ² / g or more: 1 to 30 parts by mass,
(C) Trifunctional hydrolyzable silane represented by the following general formula (I) and / or a partial hydrolysis condensate thereof: 0.001 to 5 parts by mass,
R ¹ (R ² O) ₃ Si (I)
(In the formula, R ¹ is an alkyl group having 1 to 10 carbon atoms or a phenyl group , and R ² may be the same or different, and is a hydrogen atom, or a substituted or unsubstituted, saturated or unsaturated carbon number. Is a monovalent hydrocarbon group of 1 to 20.)
(D) Water: first step of kneading 0 to 5 parts by mass,
(2) a first compound comprising a second step of heat-treating the kneaded product obtained in the first step;
(3) In the kneaded material obtained in this second step,
(E) Alkali catalyst or acid catalyst: third step of kneading 0.001 to 5 parts by mass;
(4) a second compounding comprising a fourth step of heat treating the kneaded product obtained in the third step;
(5) A method for producing an oil compound for an antifoaming agent, comprising the fifth step of kneading an acid or an alkali as a neutralizing agent in the kneaded product obtained in the fourth step.
[2]
The trifunctional hydrolyzable silane of component (C) is methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, hexyltrimethoxysilane, phenyl [1] The method for producing an oil compound for an antifoaming agent according to [1], which is selected from trimethoxysilane, decyltrimethoxysilane, and hexadecyltrimethoxysilane.
[ 3 ]
(C) The partial hydrolysis-condensation product of the trifunctional hydrolyzable silane as the component has an average degree of polymerization of 2 to 30, and is branched or linear. For antifoaming agent according to [1] or [2] A method for producing an oil compound.
[ 4 ]
[1] the production method of the antifoam composition characterized in that it comprises - a oil compound obtained by the process according to any one of [3].
In this case, the antifoaming agent composition can be prepared as a solution type, a self-emulsifying type, or an emulsion type, and is suitable for an alkaline foaming liquid.

  According to the present invention, it is possible to obtain a silicone-based antifoaming agent composition that gives good initial antifoaming property even in an alkaline foaming liquid, and that is particularly excellent in defoaming performance with little deterioration in performance over time.

Hereinafter, the present invention will be described in more detail.
Component (A) The organopolysiloxane of component (A) is essentially hydrophobic. Here, “essentially hydrophobic” means that even if some functional groups contain hydrophilic groups, the organopolysiloxane as a whole exhibits hydrophobicity.

The essentially hydrophobic organopolysiloxane (A) may be linear or branched, and those represented by the following average composition formula (II) are particularly preferred.
R ³ _m SiO _{(4-m) / 2} (II)

In the above formula (II), R ³ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms, which may be the same or different. Specific examples of the monovalent hydrocarbon group for R ³ include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group. Alkyl groups such as dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, cycloalkyl group such as cyclohexyl group, alkenyl group such as vinyl group, allyl group, aryl group such as phenyl group, tolyl group, styryl group , An aralkyl group such as an α-methylstyryl group or the like, or a chloromethyl group in which part or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with a halogen atom, a cyano group, an amino group, a hydroxyl group, etc. Chloropropyl group, 3,3,3-trifluoropropyl group, cyanoethyl group, 3-aminopropyl group, N- (β-amino Although ethyl)-.gamma.-aminopropyl group and the like, 80 mol% of the total R ³ in terms of defoaming and economy more, and particularly preferably more than 90 mol% are methyl groups.
M is a positive number satisfying 1.9 ≦ m ≦ 2.2, preferably 1.95 ≦ m ≦ 2.15.
The end of the organopolysiloxane may be blocked with a triorganosilyl group represented by R ³ ₃ Si— or a diorganohydroxysilyl group represented by (HO) R ³ ₂ Si—. Good.

The viscosity at 25 ° C. of this essentially hydrophobic organopolysiloxane (A) measured by an Ostwald viscometer is 10 to 100,000 mm ² / s from the viewpoint of defoaming and workability, preferably 50 to 30,000 mm ² / s. 10mm inferior antifoaming performance is less than ² / s, ^{100,000mm 2} / s more than a defoaming agent for oil compound workability viscosity is increased (hereinafter, sometimes referred to as a silicone oil compound) is poor .

Component (B) The finely divided silica of component (B) is preferably fumed silica or hydrophilic silica such as precipitated silica, and these can be used alone or in combination of two or more. The specific surface area of silica fine powder (BET method) is at 50 m ² / g or higher, preferably 100~700m ² / g, more preferably 150~500m ² / g. When the specific surface area is less than 50 m ² / g, preferable defoaming performance cannot be obtained.

As an example of a commercially available component (B) that can be used in the present invention, AEROSIL (registered trademark) 300 (hydrophilic fumed silica having a BET specific surface area of 300 m ² / g) that can be purchased from Nippon Aerosil Co., Ltd., AEROSIL (registered trademark) 200 (hydrophilic fumed silica having a BET specific surface area of 200 m ² / g) and NIPSIL (registered trademark) L-250 (170 m ² / g BET available from Tosoh Silica Co., Ltd.) And hydrophilic precipitated silica having a specific surface area).

  The ratio of (B) component is 1-30 mass parts with respect to 100 mass parts of (A) component, Preferably it is the range of 5-15 mass parts. If it is less than 1 part by mass, sufficient defoaming performance cannot be obtained, and if it exceeds 30 parts by mass, the viscosity of the resulting silicone oil compound increases and the workability deteriorates.

(C) Component The (C) component trifunctional hydrolyzable silane represented by the following general formula (I) and / or its partial hydrolysis condensate performs the surface hydrophobization treatment of the component (B) ( B) Improves the wettability and dispersibility of component (A), and these can be used alone or in combination of two or more.
R ¹ (R ² O) ₃ Si (I)
(In the formula, R ¹ is a monovalent organic group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and R ² may be the same or different, and may be a hydrogen atom, substituted or unsubstituted, saturated or Unsaturated monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms.)

R ^{1 in the} general formula (I) is preferably a monovalent hydrocarbon group, more preferably an alkyl group or an aryl group, and still more preferably an alkyl group having 1 to 10 carbon atoms or a phenyl group. R ^{2 is} also preferably an alkyl group.
Examples of the trifunctional hydrolyzable silane represented by the above formula (I) include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, and propyltrimethoxysilane. Hexyltrimethoxysilane, phenyltrimethoxysilane, decyltrimethoxysilane, hexadecyltrimethoxysilane and the like.

The partial hydrolysis condensate of the trifunctional hydrolyzable silane represented by the above formula (I) may be branched or linear.
The average degree of polymerization of the partially hydrolyzed condensate is preferably 2 to 30, more preferably 2 to 20. If it is too large, sufficient defoaming performance may not be obtained. In the present invention, the average degree of polymerization is a value that can be determined as the number average degree of polymerization in terms of polystyrene in GPC (gel permeation chromatography) analysis.

  In the present invention, when the partially hydrolyzed condensate is used rather than the trifunctional hydrolyzable silane represented by the formula (I), the initial antifoaming property and particularly the defoaming sustainability even in a more alkaline foaming liquid. An oil compound for an antifoaming agent excellent in the above can be obtained.

  (C) The usage-amount of a component is 0.001-5 mass parts with respect to 100 mass parts of (A) component, Preferably it is 0.01-3 mass parts. If it is less than 0.001 part by mass, sufficient antifoaming performance cannot be obtained, and if it exceeds 5 parts by mass, the defoaming performance of the silicone oil compound obtained is deteriorated.

(D) Component Water of component (D) promotes hydrolysis of component (C) and plays a role of increasing the surface treatment rate of component (B). Since component (B) may contain water such as adsorbed water, component (D) may not be essential.

  (D) The usage-amount of a component is 0-5 mass parts with respect to 100 mass parts of (A) component, Preferably it is 0.01-5 mass parts, More preferably, it is 0.01-3 mass parts. is there.

(E) Component As an alkali catalyst of (E) component, the alkali metal or alkaline-earth metal oxide, hydroxide, alkoxide, or siliconate which is a well-known alkaline catalyst used for the equilibrium reaction of polysiloxane is used. Preferably, potassium siliconate and potassium hydroxide are used. Examples of the acid catalyst include organic acids such as acetic acid, butyric acid, maleic acid, and citric acid, and inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, and sulfuric acid. As the component (E), an alkali catalyst is preferable to an acid catalyst.

  (E) The usage-amount of a component is 0.001-5 mass parts with respect to 100 mass parts of (A) component, Preferably it is 0.01-5 mass parts, More preferably, it is 0.01-3 mass. Part, more preferably 0.05 to 3 parts by mass. If it is less than 0.001 part by mass, a sufficient catalytic effect cannot be obtained, and if it exceeds 5 parts by mass, the effect of the catalyst is not greatly improved, which is disadvantageous in terms of cost.

  As the neutralizing agent for the alkali catalyst, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid or a carboxylic acid that is solid at room temperature can be used, preferably a carboxylic acid that is solid at room temperature. It is. Carboxylic acids that are solid at room temperature include monocarboxylic acids such as benzoic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, and other dicarboxylic acids, citric acid, isocitrate. Tricarboxylic acids such as acids, oxalosuccinic acid and aconitic acid are used. Of these, succinic acid, which has a small acid dissociation constant and is strong as an acid, and is easily available, is preferred. Further, as a neutralizing agent for the acid catalyst, an alkali metal or alkaline earth metal oxide, hydroxide, alkoxide or siliconate can be used, and potassium siliconate and potassium hydroxide are preferred.

  The feature of the method for producing a silicone oil compound in the present invention is that the compounding is performed in two stages of a first compounding and a second compounding. The first compounding is mainly to adsorb or immobilize the trifunctional hydrolyzable silane and / or its partially hydrolyzed condensate as component (C) on the surface of fine powder silica as component (B). The purpose of the second compounding is to immobilize the polymer component such as organopolysiloxane (A) component and reactive group derived from component (C) on the fine powder silica surface as component (B). With a purpose.

That is, in the present invention,
(1) (A) Essentially hydrophobic organopolysiloxane having a viscosity at 25 ° C. of 10 to 100,000 mm ² / s: 100 parts by mass
(B) Fine powder silica having a specific surface area of 50 m ² / g or more: 1 to 30 parts by mass,
(C) Trifunctional hydrolyzable silane represented by the following general formula (I) and / or a partial hydrolysis condensate thereof: 0.001 to 5 parts by mass, and R ¹ (R ² O) ₃ Si (I)
(In the formula, R ¹ is a monovalent organic group having 1 to 20 carbon atoms, R ² may be the same or different, and is a hydrogen atom or a substituted or unsubstituted, saturated or unsaturated carbon number. Is a monovalent hydrocarbon group of 1 to 20.)
(D) Water: first step of kneading 0 to 5 parts by mass,
(2) a first compound comprising a second step of heat-treating the kneaded product obtained in the first step;
(3) In the kneaded material obtained in this second step,
(E) Alkali catalyst or acid catalyst: third step of kneading 0.001 to 5 parts by mass;
(4) a second compounding comprising a fourth step of heat treating the kneaded product obtained in the third step;
(5) The kneaded product obtained in the fourth step includes a fifth step of kneading acid or alkali as a neutralizing agent, thereby producing an antifoaming oil compound.

  By using the silicone oil compound produced through the first to fifth steps, it is possible to obtain a defoaming agent composition having excellent initial defoaming property and defoaming durability even in a foaming liquid, particularly an alkaline foaming liquid. it can.

  In this case, in the first step, the components (A) to (C) or the components (A) to (D) are preferably kneaded at a temperature of 100 ° C. or lower, more preferably 80 ° C. or lower. It is not particularly necessary to heat from the outside, and can be kneaded at room temperature (for example, 10 to 30 ° C.). It is good to do. When kneading is performed at a temperature exceeding 100 ° C., the component (C) may volatilize and may not function effectively. The treatment time of the first step largely depends on the kneading apparatus and the scale and cannot be defined unconditionally, but is usually 0.1 to 3 hours, particularly about 0.5 to 2 hours.

  The second step is a heat treatment step for immobilizing (C) component hydrolyzed by at least one of adsorbed water in component (B) or component (D) on the surface of component (B), It heat-processes at 120-200 degreeC, Preferably it is 140-180 degreeC, Preferably kneading | mixing. When the heat treatment temperature is less than 120 ° C, the defoaming performance is inferior, and when the heat treatment temperature exceeds 200 ° C, the component (A) may be deteriorated (decomposed). The processing time of the second step largely depends on the kneading apparatus and the scale and cannot be specified unconditionally, but is usually 0.1 to 4 hours, particularly about 0.5 to 2 hours.

  In the third step, the component (E) is added to the kneaded product obtained in the second step to make the oil compound system alkaline or acidic. For the same reason as in the first step, the third step is preferably kneaded at a temperature of 100 ° C. or lower. In this case as well, kneading can be performed at room temperature (for example, 10 to 30 ° C.). The processing time of the third step is also largely dependent on the kneading apparatus and scale and cannot be defined unconditionally, but it is usually 0.05 to 3 hours, particularly about 0.1 to 2 hours.

  The fourth step is a heat treatment step for immobilizing a polymer component such as organopolysiloxane of component (A) and a reactive group derived from component (C) on the surface of fine powder silica of component (B), 120 It heat-processes at -200 degreeC, Preferably it is 140-180 degreeC, Preferably kneading | mixing. When the heat treatment temperature is less than 120 ° C, the defoaming performance is inferior, and when the heat treatment temperature exceeds 200 ° C, the component (A) may be deteriorated (decomposed). The processing time of the second step largely depends on the kneading apparatus and the scale and cannot be specified unconditionally, but is usually 0.1 to 6 hours, particularly about 2 to 4 hours.

  The fifth step is a step of neutralizing the alkali catalyst or acid catalyst used in the second compounding. For the same reason as in the first and third steps, the fifth step is preferably kneaded at a temperature of 100 ° C. or lower. In this case as well, kneading can be performed at room temperature (for example, 10 to 30 ° C.). The processing time of the third step is largely dependent on the kneading apparatus and the scale and cannot be defined unconditionally, but is usually 0.1 to 4 hours, particularly about 0.5 to 3 hours.

  Examples of the kneading machine used for kneading in the production method of the present invention include a planetary mixer, a kneader, a pressure kneader, a twin-screw kneader, an intensive mixer, an azimuth mixer, a disper, a planetary disper, etc. However, it is not particularly limited. These kneaders can be used in any of the first step to the neutralization step.

  The silicone oil compound obtained by kneading and heat-treating the above components is used as it is, or an antifoam composition containing the silicone oil compound, specifically, a solution type antifoam dispersed in an appropriate solvent. It can be used as an agent composition, a self-emulsifying antifoaming composition in combination with an organopolysiloxane modified with a polyoxyalkylene group, or an emulsion defoaming composition obtained by a known emulsifying technique. .

  Here, in the case of a solution-type antifoaming agent composition dispersed in a suitable solvent, as the solvent, a solvent in which the essentially hydrophobic organopolysiloxane as component (A) is dissolved, for example, toluene, xylene, Examples include hexane, chloroform, 2-butanone and 4-methyl-2-pentanone.

  When setting it as a solution type antifoamer composition, it is preferable that content of a silicone oil compound is 5-80 mass% of the whole antifoamer composition, More preferably, it is 30-70 mass%. If the silicone oil compound content is too low, the defoaming performance of the antifoaming composition may be inferior. If it is too high, the main purpose of the solution type antifoaming composition is to improve the dispersibility of the silicone oil compound. There are cases where it is not possible.

In addition, when a self-emulsifying antifoam composition is used in combination with an organopolysiloxane modified with a polyoxyalkylene group, the organopolysiloxane modified with a polyoxyalkylene group is represented by the following general formula (III): What is shown.
R ⁴ ₂ R ⁶ SiO— (R ⁴ ₂ SiO) _x — (R ⁴ R ⁵ SiO) _y —SiR ⁴ ₂ R ⁶ (III)

In the above formula (III), R ⁴ is the same or different unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms, specifically, methyl group, ethyl group, propyl group, isopropyl group , Butyl group, isobutyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group and other alkyl groups, cyclohexyl group and other cycloalkyl groups Group, an alkenyl group such as a vinyl group and an allyl group, an aryl group such as a phenyl group and a tolyl group, an aralkyl group such as a styryl group and an α-methylstyryl group, or a hydrogen atom bonded to a carbon atom of these groups Chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoro substituted part or all with halogen atom, cyano group, amino group, etc. Examples thereof include monovalent hydrocarbon groups such as olopropyl group, cyanoethyl group, 3-aminopropyl group, and N- (β-aminoethyl) -γ-aminopropyl group.

R ⁵ is a polyoxyalkylene group represented by the following general formula (IV).
—R ⁷ —O (CH ₂ CH ₂ O) _a — (CH ₂ (CH ₃ ) CHO) _b —R ⁸ (IV)
In the above formula (IV), R ⁷ is a divalent hydrocarbon group having 2 to 6 carbon atoms, and examples thereof include an alkylene group and an alkenylene group, such as an ethylene group, a propylene group, a butylene group, a pentylene group, and a hexylene group. Etc. R ⁸ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an acetyl group or an isocyan group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. a and b may be polymerized in a block or random manner, and the degree of polymerization thereof is such that a and b are 3 ≦ a + b ≦ 80, preferably 5 ≦ a + b ≦ 60, and a / b = 2/8 to 8/2, Preferably, it is a positive number satisfying a / b = 2.5 / 7.5 to 7.5 / 2.5.

On the other hand, R ⁶ is the same group as R ⁴ or R ⁵ , a hydroxyl group or an alkoxy group having 1 to 6 carbon atoms. Specifically, the groups exemplified as the above R ⁴ and R ⁵ and the alkoxy group include methoxy Group, ethoxy group, propoxy group, butoxy group and the like.
In the above formula (III), x is an integer of 5 to 200, preferably 20 to 150, and y is an integer of 1 to 30, preferably 1 to 20.

The organopolysiloxane modified with the polyoxyalkylene group may be used singly or as a mixture of two or more, but the viscosity at 25 ° C. measured by Ostwald viscometer is 10 to 10, 000 mm ² / s, preferably 50~8,000mm ² / s, more preferably it is possible to use those which are 500~5,000mm ² / s.

Specific examples of the organopolysiloxane modified with a polyoxyalkylene group include, but are not limited to, the following.
_{(CH 3) 3 SiO - [} (CH 3) 2 SiO] 30 - [(CH 3) R'SiO] 5 -Si (CH 3) 3
R ′: —C ₃ H ₆ O— (C ₂ H ₄ O) ₃₀ — (C ₃ H ₆ O) ₁₀ —C ₄ H ₉ ,
_{(CH 3) 3 SiO - [} (CH 3) 2 SiO] 30 - [(CH 3) R'SiO] 3 -Si (CH 3) 3
R ′: —C ₃ H ₆ O— (C ₂ H ₄ O) ₂₀ — (C ₃ H ₆ O) ₂₀ —C ₄ H ₉ ,
_{(CH 3) 3 SiO - [} (CH 3) 2 SiO] 40 - [(CH 3) R'SiO] 4 -Si (CH 3) 3
R ′: —C ₃ H ₆ O— (C ₂ H ₄ O) ₂₁ — (C ₃ H ₆ O) ₇ —COCH ₃ ,
_{(CH 3) 3 SiO - [} (CH 3) 2 SiO] 50 - [(CH 3) R''SiO] 6 - [(CH 3) R '''SiO] 1 -Si (CH 3) 3
R ″: —C ₃ H ₆ O— (C ₂ H ₄ O) ₃₂ — (C ₃ H ₆ O) ₈ —C ₄ H ₉
R ′ ″: —C ₁₂ H ₂₅ ,
(CH ₃ ) ₃ SiO — [(CH ₃ ) ₂ SiO] ₁₃₅ — [(CH ₃ ) R′SiO] ₁₅ —Si (CH ₃ ) ₃
R ′: —C ₃ H ₆ O— (C ₂ H ₄ O) ₂₁ — (C ₃ H ₆ O) ₂₁ —CH ₃ ,
_{(CH 3) 3 SiO - [} (CH 3) 2 SiO] 30 - [(CH 3) R'SiO] 5 -Si (CH 3) 3
R ′: —C ₃ H ₆ O— (C ₂ H ₄ O) _25.5 — (C ₃ H ₆ O) _8.5 —C ₄ H ₉ ,
(CH ₃ ) ₃ SiO — [(CH ₃ ) ₂ SiO] ₂₇ — [(CH ₃ ) R′SiO] ₃ —Si (CH ₃ ) ₃
R ′: —C ₃ H ₆ O— (C ₂ H ₄ O) ₂₃ — (C ₃ H ₆ O) ₂₃ —C ₄ H ₉

  In the self-emulsifying antifoaming agent composition, the organopolysiloxane modified with the polyoxyalkylene group may be used alone or in a mixture of two or more, but the content thereof is self-emulsifying. It is preferable that it is 0-95 mass% of the whole type | mold antifoamer composition, More preferably, it is 0-70 mass%. If the content is too small, the main purpose of the self-emulsifying antifoam composition to increase the dispersibility of the silicone oil compound may not be satisfied. If the content is too large, the defoaming performance as an antifoam composition may be inferior. is there. In addition, although it can be set as an effective amount when mix | blending, it is preferable to mix | blend 20 mass% or more.

In addition, in the self-emulsifying antifoaming agent composition in combination with an organopolysiloxane modified with a polyoxyalkylene group,
HO— [CH ₂ (CH ₃ ) CHO] ₃₅ —H,
HO— [CH ₂ (CH ₃ ) CHO] ₇₀ —H,
HO— (CH ₂ CH ₂ O) ₄ — [CH ₂ (CH ₃ ) CHO] ₃₀ —H,
_{HO- (C 2 H 4 O)} 25 - (C 3 H 6 O) 35 -H,
HO— (C ₃ H ₆ O) ₃₀ —H,
_{CH 2 = CHCH 2 O- (CH} 2 CH 2 O) 32 - [CH 2 (CH 3) CHO] 8 -H,
_{CH 2 = CHCH 2 O- (CH} 2 CH 2 O) 22 - [CH 2 (CH 3) CHO] 22 -C 4 H 9,
_{CH 2 = CHCH 2 O- (CH} 2 CH 2 O) 10 -CH 3
A polyoxyalkylene polymer such as exemplified by sorbitan fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, propylene glycol fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene oxypropylene alkyl ether, Non-ionic surfactants such as polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene propylene glycol fatty acid ester, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil Good.
In addition, the compositional formula illustrated above is an example, and does not restrict | limit this invention.

  In the self-emulsifying antifoaming agent composition, the polyoxyalkylene polymer is blended in order to increase the dispersibility of the silicone oil compound, and even if it is used alone or in combination of two or more. However, the content is preferably 0 to 95% by mass, more preferably 0 to 70% by mass, based on the entire self-emulsifying antifoam composition. When there is too much content, the defoaming performance as an antifoamer composition may be inferior. In addition, although it can be set as an effective amount when mix | blending, it is preferable to mix | blend 20 mass% or more.

  Moreover, in the self-emulsifying antifoaming agent composition, the nonionic surfactant is blended in order to improve the dispersibility of the silicone oil compound, and even if it is used alone, it is a mixture of two or more. However, the content is preferably 0 to 95% by mass, more preferably 0 to 70% by mass, based on the entire self-emulsifying antifoam composition. When there is too much content, the defoaming performance as an antifoamer composition may be inferior. In addition, although it can be set as an effective amount when mix | blending, it is preferable to mix | blend 20 mass% or more.

  Moreover, when setting it as a self-emulsification type antifoamer composition, it is preferable that content of a silicone oil compound is 5-80 mass% of the whole self-emulsification type antifoamer composition, More preferably, it is 10-70 mass. %, And more preferably 20 to 60% by mass. If the content of the silicone oil compound is too small, the defoaming performance as an antifoaming composition may be inferior. If the content is too large, the main purpose of the self-emulsifying antifoaming composition is to increase the dispersibility of the silicone oil compound. You may not be satisfied.

  Further, when an emulsion type antifoaming agent composition is used, a known method can be used. As an emulsifier for emulsifying a silicone oil compound, the above-mentioned organopolysiloxane modified with a polyoxyalkylene group or polyoxyalkylene can be used. An alkylene polymer, a nonionic surfactant, etc. can be used.

  In the emulsion type antifoaming agent composition, the organopolysiloxane modified with the polyoxyalkylene group may be used singly or in a mixture of two or more, but the content thereof is an emulsion type antifoaming agent. It is preferable that it is 0-30 mass% of the whole foaming agent composition, More preferably, it is 1-20 mass%. When content exceeds 30 mass%, the defoaming performance of a composition may worsen.

  Further, in the emulsion type antifoaming agent composition, the polyoxyalkylene polymer serves as an emulsification aid, and may be used alone or in a mixture of two or more. Is preferably 0 to 40% by mass, more preferably 0 to 20% by mass, based on the whole emulsion antifoam composition. When content exceeds 40 mass%, the emulsification characteristic of a composition may worsen. In addition, although it can be set as an effective amount when mix | blending, it is preferable to mix | blend 5 mass% or more.

  Furthermore, in the emulsion-type antifoaming agent composition, the nonionic surfactant is for dispersing the silicone oil compound in water, and even if it is used alone or in a mixture of two or more. However, the content is preferably 0 to 20% by mass, more preferably 1 to 12% by mass, based on the whole emulsion antifoam composition. When it exceeds 20 mass%, the viscosity of an antifoamer composition may become high and workability | operativity may worsen.

  Moreover, when setting it as an emulsion type antifoamer composition, it is preferable that content of a silicone oil compound is 5-50 mass% of the whole emulsion type antifoamer composition, More preferably, it is 10-40 mass%. is there. If the content of the silicone oil compound is too small, the defoaming performance as the antifoaming composition may be inferior, and if it is too large, the viscosity of the antifoaming composition may be increased and workability may be deteriorated.

  In the emulsion type antifoaming agent composition, water necessary for emulsifying each component such as silicone oil compound, organopolysiloxane modified with polyoxyalkylene group, polyoxyalkylene polymer, nonionic surfactant and the like. The amount is the balance with respect to the total content of each component, preferably 50 to 2,000 parts by mass, more preferably 80 to 400 parts by mass with respect to 100 parts by mass of each component in total. Add to be.

  The emulsion-type antifoaming agent composition is a known method, for example, a mixer / disperser such as a homomixer, homogenizer, colloid mill or the like, while mixing a predetermined amount of each component other than water and heating as necessary. It can be prepared by stirring and emulsifying, but in particular, after a predetermined amount of each component other than water is uniformly mixed and dispersed, a part of water is added, and the remaining after stirring and emulsification A method of adding water and stirring and mixing uniformly is preferable.

  In addition, a small amount of preservatives and bactericides may optionally be added to the emulsion antifoam composition for the purpose of preserving. Specific examples of the preservative / disinfectant include sodium hypochlorite, sorbic acid, potassium sorbate, salicylic acid, sodium salicylate, benzoic acid, sodium benzoate, parabens, isothiazoline compounds and the like. This addition amount is preferably 0 to 0.5% by mass, particularly preferably 0.005 to 0.5% by mass, based on the total emulsion antifoam composition.

  In addition, a small amount of a thickener may be optionally added to the emulsion antifoam composition for the purpose of thickening. Specific examples of the thickener include polyacrylic acid, sodium polyacrylate, acrylic acid / methacrylic acid copolymer, sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, xanthan gum, and guar gum. This addition amount is preferably 0 to 1.0% by mass, and particularly preferably 0.01 to 0.5% by mass, based on the whole emulsion antifoam composition.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example. In the following examples, the viscosity is a value at 25 ° C. measured with an Ostwald viscometer, and the average degree of polymerization is a value obtained as a number average degree of polymerization in terms of polystyrene in GPC (gel permeation chromatography) analysis.

[Example 1]
As an essentially hydrophobic organopolysiloxane, 100 parts by mass of dimethylpolysiloxane having a viscosity of 10,000 mm ² / s and both ends of the molecular chain blocked with trimethylsilyl groups, as fine powder silica, AEROSIL 300 [Japan 5 parts by mass of a specific surface area of 300 m ² / g] manufactured by Aerosil Co., Ltd., and 0.3 parts by mass of propyltrimethoxysilane and 0.3 parts by mass of water were kneaded for 1 hour using a planetary mixer. . Thereafter, the temperature was raised to 150 ° C. and kneading was continued for 2 hours. After cooling to 100 ° C. or lower, 2 parts by weight of potassium siliconate containing 3% by weight of potassium hydroxide as an alkaline catalyst was added and kneaded at 100 ° C. or lower for 0.1 hour, and then the temperature was raised to 150 ° C. while kneaded. The temperature was maintained, the temperature was raised, and the mixture was kneaded for 4 hours in total. After cooling to 100 ° C or lower, succinic acid was added and neutralized by kneading for 3 hours to obtain a silicone oil compound (a-1).
30 parts by mass of this silicone oil compound (a-1) has an average composition of the following formula: R ⁴ ₂ R ⁶ SiO— (R ⁴ ₂ SiO) _x — (R ⁴ R ⁵ SiO) _y —SiR ⁴ ₂ R ⁶
(However, R ⁴ and R ⁶ are —CH ₃ , R ⁵ is —C ₃ H ₆ O (C ₂ H ₄ O) ₂₁ (C ₃ H ₆ O) ₂₁ CH ₃ , x is 135, and y is 15. .)
In addition, 70 parts by mass of a polyoxyalkylene-modified organosiloxane (a-2) having a viscosity of 2,500 mm ² / s was mixed at room temperature to prepare a self-emulsifying antifoam composition (A).

[Example 2]
After heating and dissolving a mixture of 20 parts by mass of the silicone oil compound (a-1), 4 parts by mass of sorbitan monostearate and 6 parts by mass of polyoxyethylene (55) monostearate of Example 1, 70 parts by mass of water was added. In addition, the mixture was stirred and emulsified with a homomixer to prepare an emulsion antifoam composition (B).

[Example 3]
As an essentially hydrophobic organopolysiloxane, 100 parts by mass of dimethylpolysiloxane having a viscosity of 8,000 mm ² / s and both ends of the molecular chain blocked with trimethylsilyl groups, and as fine powder silica, AEROSIL 200 [Japan 12 parts by mass of a specific surface area of 200 m ² / g] manufactured by Aerosil Co., Ltd. and 0.72 parts by mass of phenyltrimethoxysilane as a silica surface treatment agent were kneaded for 1 hour using a planetary mixer. Thereafter, the temperature was raised to 150 ° C. and kneading was continued for 2 hours. After cooling to 100 ° C. or lower, 3 parts by weight of potassium siliconate containing 3% by weight of potassium hydroxide as an alkaline catalyst was added and kneaded at 100 ° C. or lower for 0.1 hour, and then the temperature was raised to 150 ° C. while kneaded. Warmed and kneaded at 150 ° C. for 2 hours. After cooling to 100 ° C. or lower, succinic acid was added and neutralized by kneading for 3 hours to obtain a silicone oil compound (c-1).
30 parts by mass of this silicone oil compound (c-1) has an average composition of the following formula: R ⁴ ₂ R ⁶ SiO— (R ⁴ ₂ SiO) _x — (R ⁴ R ⁵ SiO) _y —SiR ⁴ ₂ R ⁶
(However, R ⁴ and R ⁶ are —CH ₃ , R ⁵ is —C ₃ H ₆ O (C ₂ H ₄ O) _25.5 (C ₃ H ₆ O) _8.5 C ₄ H ₉ , x is 30, y is 5 .)
50 parts by mass of polyoxyalkylene-modified organosiloxane (c-2) having a viscosity of 1,000 mm ² / s and an average composition of the following formula: HO— (C ₂ H ₄ O) ₂₅ — (C ₃ H ₆ O) ₃₅ -H
A self-emulsifying antifoam composition (C) was prepared by mixing 20 parts by mass of a polyoxyalkylene polymer (c-3) represented by

[Example 4]
After heating and dissolving a mixture of 20 parts by mass of the silicone oil compound (c-1), 6 parts by mass of sorbitan monostearate and 6 parts by mass of polyoxyethylene (55) monostearate of Example 3, 68 parts by mass of water was added. In addition, the mixture was stirred and emulsified with a homomixer to prepare an emulsion antifoam composition (D).

[Example 5]
As an essentially hydrophobic organopolysiloxane, 100 parts by mass of dimethylpolysiloxane having a viscosity of 10,000 mm ² / s and both ends of the molecular chain blocked with trimethylsilyl groups, as fine powder silica, AEROSIL 300 [Japan 5 parts by mass of a specific surface area of 300 m ² / g] manufactured by Aerosil Co., Ltd. 0.3 parts by mass of an oligomer obtained by partially hydrolyzing propyltrimethoxysilane and condensing to an average degree of polymerization of 3 using a silica surface treatment agent, Three parts by mass were kneaded for 1 hour using a planetary mixer. Thereafter, the temperature was raised to 150 ° C. and kneading was continued for 2 hours. After cooling to 100 ° C. or lower, 3 parts by weight of potassium siliconate containing 3% by weight of potassium hydroxide as an alkaline catalyst was added and kneaded at 100 ° C. or lower for 0.1 hour, and then the temperature was raised to 150 ° C. while kneaded. Warmed and kneaded at 150 ° C. for 2 hours. After cooling to 100 ° C. or lower, succinic acid was added and neutralized by kneading for 3 hours to obtain a silicone oil compound (e-1).
30 parts by mass of this silicone oil compound (e-1) has an average composition of the following formula: R ⁴ ₂ R ⁶ SiO— (R ⁴ ₂ SiO) _x — (R ⁴ R ⁵ SiO) _y —SiR ⁴ ₂ R ⁶
(However, R ⁴ and R ⁶ are —CH ₃ , R ⁵ is —C ₃ H ₆ O (C ₂ H ₄ O) ₂₁ (C ₃ H ₆ O) ₂₁ CH ₃ , x is 135, and y is 15. .)
In expressed, and viscosity to prepare self-emulsifying antifoam composition (E) were mixed at room temperature a polyoxyalkylene-modified organosiloxane (e-2) 70 parts by weight is 2,500 mm ² / s.

[Example 6]
After heating and dissolving a mixture of 20 parts by mass of the silicone oil compound (e-1), 4 parts by mass of sorbitan monostearate and 6 parts by mass of polyoxyethylene (55) monostearate of Example 5, 70 parts by mass of water was added. In addition, the mixture was stirred and emulsified with a homomixer to prepare an emulsion antifoam composition (F).

[Example 7]
As an essentially hydrophobic organopolysiloxane, 100 parts by mass of dimethylpolysiloxane having a viscosity of 8,000 mm ² / s and both ends of the molecular chain blocked with trimethylsilyl groups, and as fine powder silica, AEROSIL 200 [Japan Planetary mixer containing 0.72 parts by mass of an oligomer obtained by partial hydrolysis of phenyltrimethoxysilane and condensing to an average degree of polymerization of 10 using 12 parts by mass of a specific surface area of 200 m ² / g] manufactured by Aerosil Co., Ltd. And kneaded for 1 hour. Thereafter, the temperature was raised to 150 ° C. and kneading was continued for 2 hours. After cooling to 100 ° C. or lower, 3 parts by weight of potassium siliconate containing 3% by weight of potassium hydroxide as an alkaline catalyst was added and kneaded at 100 ° C. or lower for 0.1 hour, and then the temperature was raised to 150 ° C. while kneaded. Warmed and kneaded at 150 ° C. for 2 hours. After cooling to 100 ° C. or below, succinic acid was added and neutralized by kneading for 3 hours to obtain a silicone oil compound (g-1).
30 parts by mass of this silicone oil compound (g-1) has an average composition of the following formula: R ⁴ ₂ R ⁶ SiO— (R ⁴ ₂ SiO) _x — (R ⁴ R ⁵ SiO) _y —SiR ⁴ ₂ R ⁶
(However, R ⁴ and R ⁶ are —CH ₃ , R ⁵ is —C ₃ H ₆ O (C ₂ H ₄ O) _25.5 (C ₃ H ₆ O) _8.5 C ₄ H ₉ , x is 30, y is 5 .)
And 50 parts by mass of polyoxyalkylene-modified organosiloxane (g-2) having a viscosity of 1,000 mm ² / s and an average composition of the following formula: HO— (C ₂ H ₄ O) ₂₅ — (C ₃ H ₆ O) ₃₅ -H
A self-emulsifying antifoaming composition (G) was prepared by mixing 20 parts by mass of a polyoxyalkylene polymer (g-3) represented by

[Example 8]
After heating and dissolving a mixture of 20 parts by mass of the silicone oil compound (g-1), 6 parts by mass of sorbitan monostearate and 6 parts by mass of polyoxyethylene (55) monostearate of Example 7, 68 parts by mass of water was added. In addition, the emulsion type antifoaming agent composition (H) was prepared by stirring and emulsifying with a homomixer.

[Comparative Example 1]
As an essentially hydrophobic organopolysiloxane, 100 parts by mass of dimethylpolysiloxane having a viscosity of 10,000 mm ² / s and both ends of the molecular chain blocked with trimethylsilyl groups, as fine powder silica, AEROSIL 300 [Japan 5 parts by mass of a specific surface area of 300 m ² / g] manufactured by Aerosil Co., Ltd., and 0.3 parts by mass of propyltrimethoxysilane and 0.3 parts by mass of water were kneaded for 1 hour using a planetary mixer. . Thereafter, the temperature was raised to 150 ° C. and kneaded for 3 hours to obtain a silicone oil compound (i-1).
30 parts by mass of this silicone oil compound (i-1) has an average composition of the following formula: R ⁴ ₂ R ⁶ SiO— (R ⁴ ₂ SiO) _x — (R ⁴ R ⁵ SiO) _y —SiR ⁴ ₂ R ⁶
(However, R ⁴ and R ⁶ are —CH ₃ , R ⁵ is —C ₃ H ₆ O (C ₂ H ₄ O) ₂₁ (C ₃ H ₆ O) ₂₁ CH ₃ , x is 135, and y is 15. .)
And 70 parts by mass of a polyoxyalkylene-modified organosiloxane (i-2) having a viscosity of 2,500 mm ² / s was mixed at room temperature to prepare a self-emulsifying antifoam composition (I).

[Comparative Example 2]
After heating and dissolving a mixture of 20 parts by mass of the silicone oil compound (i-1), 4 parts by mass of sorbitan monostearate and 6 parts by mass of polyoxyethylene (55) monostearate of Comparative Example 1, 68 parts by mass of water was added. In addition, the mixture was stirred and emulsified with a homomixer to prepare an emulsion antifoam composition (J).

[Comparative Example 3]
As an essentially hydrophobic organopolysiloxane, 100 parts by mass of dimethylpolysiloxane having a viscosity of 10,000 mm ² / s and blocked at both ends of a molecular chain by a trimethylsilyl group, as fine powder silica, AEROSIL 200 [Japan Aerosil, specific surface area of 200 m ² / g], 5 parts by mass, 2 parts by mass of potassium siliconate containing 3% by mass of potassium hydroxide as an alkaline catalyst, using a planetary mixer in a nitrogen gas atmosphere The mixture was kneaded at 150 ° C. for 3 hours. After cooling to 100 ° C. or lower, it was neutralized with succinic acid to obtain a silicone oil compound (k-1).
30 parts by mass of this silicone oil compound (k-1) has an average composition of the following formula: R ⁴ ₂ R ⁶ SiO— (R ⁴ ₂ SiO) _x — (R ⁴ R ⁵ SiO) _y —SiR ⁴ ₂ R ⁶
(However, R ⁴ and R ⁶ are —CH ₃ , R ⁵ is —C ₃ H ₆ O (C ₂ H ₄ O) ₂₁ (C ₃ H ₆ O) ₂₁ CH ₃ , x is 135, and y is 15. .)
And 70 parts by mass of a polyoxyalkylene-modified organosiloxane (k-2) having a viscosity of 2,500 mm ² / s was mixed at room temperature to prepare a self-emulsifying antifoam composition (K).

  The antifoam compositions (A) to (K) obtained in Examples 1 to 8 and Comparative Examples 1 to 3 were evaluated by the following methods. The results are shown in Table 1.

[Evaluation method]
A 100 mL glass bottle was filled with 50 g of a hardwood-derived sulfite pulp waste liquid whose nonvolatile content was adjusted to 8% by mass, and this was preheated at 80 ° C.
Defoaming property (initial):
After adding 0.1% by mass of the defoamer composition as an active ingredient to the test solution preheated at 80 ° C., the mixture is shaken with a shaker for 30 seconds to be foamed, and the foam height (liquid level + foam) The defoaming property was evaluated by measuring the time until defoaming.
Defoaming property (persistence):
After adding 0.1% by mass of each antifoam composition as an active ingredient to the above sulfite pulp waste liquid at 80 ° C., it is shaken every predetermined time (after 30 minutes and 120 minutes). The defoaming property was evaluated by measuring the foam height (liquid level + foam) and the time until defoaming by shaking for 30 seconds.

Claims (8)

(1) (A) Essentially hydrophobic organopolysiloxane having a viscosity at 25 ° C. of 10 to 100,000 mm ² / s: 100 parts by mass
(B) Fine powder silica having a specific surface area of 50 m ² / g or more: 1 to 30 parts by mass,
(C) Trifunctional hydrolyzable silane represented by the following general formula (I) and / or a partial hydrolysis condensate thereof: 0.001 to 5 parts by mass,
R ¹ (R ² O) ₃ Si (I)
(In the formula, R ¹ is an alkyl group having 1 to 10 carbon atoms or a phenyl group , and R ² may be the same or different, and is a hydrogen atom, or a substituted or unsubstituted, saturated or unsaturated carbon number. Is a monovalent hydrocarbon group of 1 to 20.)
(D) Water: first step of kneading 0 to 5 parts by mass,
(2) a first compound comprising a second step of heat-treating the kneaded product obtained in the first step;
(3) In the kneaded material obtained in this second step,
(E) Alkali catalyst or acid catalyst: third step of kneading 0.001 to 5 parts by mass;
(4) a second compounding comprising a fourth step of heat treating the kneaded product obtained in the third step;
(5) A method for producing an oil compound for an antifoaming agent, comprising the fifth step of kneading an acid or an alkali as a neutralizing agent in the kneaded product obtained in the fourth step.   The trifunctional hydrolyzable silane of component (C) is methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, hexyltrimethoxysilane, phenyl The method for producing an oil compound for an antifoaming agent according to claim 1, wherein the method is selected from trimethoxysilane, decyltrimethoxysilane, and hexadecyltrimethoxysilane. An oil compound for an antifoaming agent according to claim 1 or 2, wherein the partial hydrolysis-condensation product of the (C) component trifunctional hydrolyzable silane has an average degree of polymerization of 2 to 30, and is branched or linear. Manufacturing method. Method for producing a defoamer composition comprising the oil compound obtained in claim 1 to 3 any one method according to. The method for producing an antifoaming composition according to claim 4, which is a solution type. The method for producing an antifoaming composition according to claim 4, wherein the composition is a self-emulsifying type in combination with an organopolysiloxane modified with a polyoxyalkylene group. The method for producing an antifoam composition according to claim 4, which is an emulsion type. The method for producing an antifoam composition according to any one of claims 4 to 7 , which is used for an alkaline foaming liquid.