Silicone oil compound for antifoam agent and antifoam composition

Abstract

Provided is an oil complex that is particularly excellent in initial defoaming properties in an alkaline foaming solution, has little deterioration over time, and has excellent defoaming durability, and a defoaming agent composition containing the oil complex. An (A) silicon oil complex for a defoaming agent, which is a crosslinked product of (a) a hydrophobic organopolysiloxane having a viscosity of 10 to 100,000 mm 2 / s at 25°C: 100 parts by mass (b) finely powdered silica: 1 to 15 parts by mass, characterized in that, in a particle size distribution of organopolysiloxane-silica crosslinked material measured by a single particle optical sizing technique (SPOS method) for a substance obtained by diluting the above oil complex with toluene, the median particle size based on the volume standard is 5 to 25 μm.

Description

Technical Field

[0001] This invention relates to a silicone oil complex for defoaming in which the particle size of the organopolysiloxane-silica crosslinker in the oil complex is controlled within a certain range, and to a silicone oil complex for defoaming that exhibits excellent initial defoaming properties and defoaming persistence, especially in alkaline foaming liquids, as well as internal addition stability, and to a defoaming composition containing the silicone oil complex for defoaming. Background Technology

[0002] Silicone-based defoamers are widely used in foaming processes in chemical, food, petroleum, paper, textile, and pharmaceutical industries due to the very low surface tension of silicone and its insolubility in most solvents. A typical silicone-based defoamer is an oil-complex type, combining silicone oils such as dimethylpolysiloxane, methylphenylpolysiloxane, and methylvinylpolysiloxane with micronized silica powder.

[0003] In addition, emulsion-type defoamers, which are formed by emulsifying and dispersing the oil-complex type defoamer with a surfactant in water, are also commonly used, as are self-emulsifying defoamers, which are formed by mixing an alkylene oxide-modified organopolysiloxane with an oil-complex type defoamer. However, the defoaming performance of these defoamers largely depends on the oil-complex type defoamer as the base raw material, and existing technologies suffer from problems such as insufficient initial defoaming performance, especially for alkaline foaming liquids, and insufficient internal stability.

[0004] To address these issues, it has been disclosed that defoamer compositions with improved alkali resistance are prepared by mixing hydrophobic organopolysiloxanes and micronized silica in the presence of an alkaline catalyst to produce organopolysiloxane-silica crosslinks (Patent Document 1: Japanese Patent No. 5163909); defoamer compositions obtained by actively introducing organopolysiloxane-silica crosslinks using terminal alkoxy-modified organopolysiloxanes (Patent Document 2: Japanese Patent No. 6179479, Patent Document 3: Japanese Patent No. 6197768); and defoamer compositions containing R3SiO2 and micronized silica. 1 / 2 Unit (M unit) and SiO 4 / 2Defoamer compositions obtained by preparing organopolysiloxane-silica crosslinks together with organopolysiloxane resins of unit (Q unit) (Patent Document 4: Japanese Patent No. 5922305); defoamer compositions using polyorganosiloxanes capable of addition reactions via hydrosilylation, and containing crosslinks of organopolysiloxanes and silica that have been branched or crosslinked via hydrosilylation (Patent Document 5: Japanese Patent No. 5346283), etc. It is known that defoamer compositions using these organopolysiloxane-silica crosslinks can achieve sustained defoaming properties even for strongly alkaline foaming liquids such as black liquor or cutting oil.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 5163909

[0008] Patent Document 2: Japanese Patent No. 6179479

[0009] Patent Document 3: Japanese Patent No. 6197768

[0010] Patent Document 4: Japanese Patent No. 5922305

[0011] Patent Document 5: Japanese Patent No. 5346283 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] These defoamer compositions generally possess high defoaming performance, particularly exhibiting alkali resistance with minimal degradation over time, even in alkaline foaming solutions. However, if the crosslinking becomes excessively large, emulsion stability during emulsification decreases, or dispersibility diminishes, often resulting in reduced defoaming performance. Conversely, if the crosslinking is too small, the desired defoaming effect and defoaming persistence in alkaline foaming solutions are not achieved, sometimes failing to meet the expected performance. Currently, there is no method to confirm the aforementioned defoaming performance in defoamer compositions. Evaluation requires performance verification under actual or near-actual usage conditions each time, making it difficult to control quality deviations during quality management.

[0014] Therefore, the object of the present invention is to provide an oil complex that exhibits good initial defoaming properties even in alkaline foaming liquids, with minimal degradation over time and excellent defoaming persistence, as well as a defoaming agent composition containing the oil complex.

[0015] Solution for solving the problem

[0016] To achieve the above objectives, the inventors, through meticulous research, discovered that by using a silicone oil composite containing organopolysiloxane and micronized silica as an antifoaming agent, and by measuring the particle size distribution of the organopolysiloxane-silica crosslinked material diluted with toluene using Single Particle Optical Sizing (SPOS) technology, and adjusting the particle size distribution of the organopolysiloxane-silica crosslinked material to a specific range based on the median particle size standard of the volume standard, the material exhibits initial defoaming properties, particularly persistent defoaming properties in alkaline foaming liquids, while also maintaining emulsification stability when prepared as an emulsion, thus completing this invention.

[0017] Therefore, the present invention provides a silicone oil complex for defoaming as shown below and a defoaming composition containing the silicone oil complex for defoaming.

[0018] [1] A silicone oil complex (A) for use as an antifoaming agent, comprising a crosslinked product of components (a) and (b) below, wherein,

[0019] (a) Viscosity of 10–100,000 mm at 25°C 2 / s of hydrophobic organopolysiloxane: 100 parts by weight

[0020] (b) Micronized silica powder: 1-15 parts by weight

[0021] The characteristic feature is that, in the particle size distribution of the organopolysiloxane-silica crosslinked material obtained by diluting the above-mentioned oil complex with toluene using single-particle optical sizing (SPOS method), the median particle size of the particle size standard based on volume is 5 to 25 μm.

[0022] [2] Silicone oil complexes for defoamers as described in [1],

[0023] It is a cross-linked product of components (a), (b), and (c), wherein,

[0024] Component (c) contains R 1 R 2 R 3 SiO 1 / 2 unit and SiO 4 / 2 unit, and relative to SiO 4 / 2 Unit R 1 R 2 R 3 SiO 1 / 2 The unit molar ratio is 0.4–2.0, and the amount is 0.1–15 parts by mass of organopolysiloxane resin.

[0025] (R 1 R 2 and R 3 Each is independently represented as an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms.

[0026] [3] Silicone oil complexes for defoamers as described in [1],

[0027] It is a cross-linked product of components (a), (b), and (c), wherein,

[0028] Component (c) contains R 1 R 2 R 3 SiO 1 / 2 unit and SiO 4 / 2 unit, and relative to SiO 4 / 2 Unit R 1 R 2 R 3 SiO 1 / 2 The unit molar ratio is 0.6–1.0, and the amount is 1.0–10 parts by mass of organopolysiloxane resin.

[0029] (R 1 R 2 and R 3 Each is independently represented as an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms.

[0030] [4] Silicone oil complexes for defoamers as described in [1],

[0031] It is a product treated with an alkaline catalyst.

[0032] [5] Silicone oil complexes for defoamers as described in [2] or [3],

[0033] It is a product treated with an alkaline catalyst.

[0034] [6] A self-emulsifying defoamer composition.

[0035] It contains (A) a silicone oil complex for defoaming as described in any one of [1] to [5] and (B) an organopolysiloxane modified with polyoxyalkylene.

[0036] [7] An emulsion-type defoamer composition,

[0037] It contains (A) a silicone oil complex for defoaming, (C) a surfactant and (E) water, as described in any one of [1] to [5].

[0038] [8] A method for manufacturing a silicone oil composite for use as an antifoaming agent,

[0039] The method for manufacturing a silicone oil composite for defoaming as described in any one of [1] to [5] is characterized by comprising the steps of mixing component (b) with component (a) and heating the mixture to perform a crosslinking treatment.

[0040] In the mixing step, a step of dispersing component (b) into component (a) is set to adjust the median particle size of the organopolysiloxane-silica crosslink to 5–25 μm.

[0041] [9] The method for manufacturing silicone oil complexes for defoamers as described in [8]

[0042] In the mixing step, a dispersion step is performed by applying a shear at a circumferential speed of 2.75 to 15.8 m / s using a disperser.

[0043]

[10] The method for manufacturing silicone oil complexes for defoamers as described in [8]

[0044] In the mixing step, a kneader is used for the dispersion step, wherein component (b) is mixed with 1 / 3 to 1 / 5 of the amount of component (a) and stirred at 15 to 30 rpm to thicken, and the remaining amount of component (a) is mixed and diluted.

[0045] The effects of the invention

[0046] According to the present invention, an organosilicon-based silicone oil complex and defoamer composition can be provided that exhibits defoaming properties in the initial stage, particularly in alkaline foaming liquids, while also maintaining emulsification stability when prepared as an emulsion. Detailed Implementation

[0047] The present invention will now be described in more detail.

[0048] <(a) Ingredients: Organopolysiloxane>

[0049] (a) The organopolysiloxane of component (a) is a hydrophobic organopolysiloxane. Here, hydrophobic means that even if some functional groups contain hydrophilic groups, the organopolysiloxane as a whole still exhibits hydrophobicity.

[0050] The hydrophobic (a) organopolysiloxane can be a linear organopolysiloxane or one containing R. 4 SiO 3 / 2 (T unit) and / or SiO 4 / 2 (Q unit) branched organopolysiloxane, particularly preferably organopolysiloxane represented by the following average composition formula (I).

[0051] R4 n SiO (4-n) / 2 (I)

[0052] In equation (I) above, R 4 The groups are monovalent hydrocarbon groups with 1 to 18 carbon atoms, either substituted or unsubstituted; they can be the same or different. As R 4 The monovalent hydrocarbon group, specifically, can include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, and octadecyl; cyclohexyl groups such as cyclohexyl; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl and tolyl; aralkyl groups such as styryl and α-methylstyryl; or chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, cyanoethyl, 3-aminopropyl, N-(β-aminoethyl)-γ-aminopropyl, etc., where some or all of the hydrogen atoms of these groups are replaced by halogen atoms, cyano, amino, hydroxyl, etc. However, from the perspective of defoaming and economy, all R groups are preferred. 4 More than 80%, particularly preferably more than 90%, of the methyl group is present. Furthermore, n is a positive number of 1.9 ≤ n ≤ 2.2, preferably a positive number of 1.95 ≤ n ≤ 2.15. It should be noted that the terminus of the organopolysiloxane can be R... 4 The 3Si- group, representing a tri-organosilylate end-capped structure, can also be used as (HO)R. 4 The 2Si-represented diorganohydroxysilyl end-capping can also be used as (R 17 O) m R 18 3-m Si-represents alkoxysilyl-terminated (R) 17 Represented as a hydrogen atom or a monovalent hydrocarbon group, R 18 This represents a monovalent organic group, where m is an integer from 1 to 3.

[0053] (a) Organopolysiloxane, considering defoaming properties and workability, preferably has a viscosity of 10–100,000 mmHg as measured by an Ostwald viscometer at 25°C. 2 / s, more preferably 50 to 30000 mm 2 / s. If the viscosity is below the lower limit mentioned above, the defoaming performance of the silicone oil compound deteriorates; if it exceeds the upper limit mentioned above, the viscosity of the silicone oil compound increases, resulting in poor workability.

[0054] The proportion of (a) organopolysiloxane used, based on the total amount of the silicone oil composite used as defoamer in (A), is preferably 75-99.5% by mass, more preferably 80-99% by mass. If the proportion is lower than the lower limit of the above-mentioned proportion, the addition of (b) micronized silica or (c) organopolysiloxane resin increases, leading to an increase in the viscosity of the silicone oil composite, which tends to result in poor workability. If the proportion exceeds the upper limit of the above-mentioned proportion, the addition of (b) micronized silica or (c) organopolysiloxane resin decreases, which tends to reduce defoaming performance.

[0055] Preferred examples of organopolysiloxanes represented by formula (I) above include dimethyl polysiloxane, diethyl polysiloxane, methylphenyl polysiloxane, dimethylsiloxane / diphenylsiloxane copolymer, methyl(3,3,3-trifluoropropyl)polysiloxane, and α,ω-dihydroxydimethyl polysiloxane. They can be used individually or in combination of two or more.

[0056] <(b) Composition: Micronized silica>

[0057] (b) The micronized silica component can be any known micronized silica, such as wet silica like precipitated silica, or dry silica like silica dry gel or fumed silica. While all of the above-mentioned silicas are hydrophilic, the present invention can use either the hydrophilic silica directly or hydrophobic silica formed by surface treatment of silica with a compound containing an organosilanes. One type of micronized silica can be used alone, or two or more types can be used in combination.

[0058] Commercially available products can be used for this micro-powdered silica. Examples include products under the trade names AEROSIL (registered trademark) (manufactured by NIPPON AEROSIL CO.,LTD.), SIPERNAT (registered trademark) (manufactured by Evonik Japan Co.,Ltd.), NIPSIL (registered trademark), NIPGEL (registered trademark) (all manufactured by Tosoh Silicon Chemical Co., Ltd., Japan), and SYLYSIA (registered trademark) (manufactured by FUJI SILYSIA CHEMICAL LTD.). The micro-powdered silica is preferably characterized by a specific surface area of ​​50 m² based on the BET method. 2 / g or more, more preferably 100-500m 2 / g, further preferably 150-500m 2 / g of fine powdered silica. If the specific surface area is less than 50m² 2 If the defoaming rate is / g, then sometimes the optimal defoaming performance cannot be obtained.

[0059] (b) The particle size of the micro-powdered silica is the median particle size of the particle size distribution measured by single-particle optical sizing (SPOS method) as a volume standard, preferably in the range of 0.75 to 10 μm, more preferably in the range of 1 to 8 μm. If the particle size is within such a range, the particle size distribution of the organopolysiloxane-silica crosslink is controlled within a suitable range, thereby easily obtaining preferred defoaming performance.

[0060] The amount of (b) micronized silica used is 1 to 15 parts by mass, preferably 3 to 10 parts by mass, relative to 100 parts by mass of (a) organopolysiloxane. If the amount of micronized silica used in (b) is less than 1 part by mass, the defoaming performance deteriorates; if the amount of micronized silica used in (b) is more than 15 parts by mass, the viscosity of (A) silicone oil composite increases, resulting in poor workability.

[0061] <(c) Composition: Organopolysiloxane resin>

[0062] The organopolysiloxane resin is any component that increases the crosslinking points of the silicone oil complex used as a defoamer (A), improves defoaming properties, and particularly enhances the persistence of defoaming in alkaline foaming liquids. The organopolysiloxane resin contains R. 1 R 2 R 3 SiO 1 / 2 (M) unit and SiO 4 / 2 (Q) unit, the molar ratio of M unit / Q unit is preferably 0.4 to 2.0, and particularly preferably 0.6 to 1.0.

[0063] Here, the so-called "includes R" 1 R 2 R 3 SiO 1 / 2 (M) unit and SiO 4 / 2 "(Q) unit" refers to the fact that almost all units in the (c) organopolysiloxane resin are M units and Q units, and the molar ratio of [M units and Q units] / [other units] is preferably 90 / 10 or more, more preferably 95 / 5 or more.

[0064] (c) R of organopolysiloxane resins 1 R 2 and R 3 Each of the groups is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms, but from the perspective of defoaming and economy, it is preferred that (c) 80% or more, and particularly preferred that 90% or more, of the total organic polysiloxane resin is methyl.

[0065] The organopolysiloxane resin may also contain up to 10% hydroxyl or alkoxy groups.

[0066] (c) An organopolysiloxane resin, particularly preferably an organopolysiloxane resin represented by the following average composition formula (II).

[0067] R 5 n SiO (4-n) / 2 (II)

[0068] In equation (II) above, R 5 The groups are monovalent hydrocarbon groups with 1 to 18 carbon atoms, either substituted or unsubstituted; they can be the same or different. As R 5 The monovalent hydrocarbon group, specifically, can include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, and octadecyl; cyclohexyl groups such as cyclohexyl; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl and tolyl; aralkyl groups such as styryl and α-methylstyryl; or chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, cyanoethyl, 3-aminopropyl, N-(β-aminoethyl)-γ-aminopropyl, etc., where some or all of the hydrogen atoms of these groups are replaced by halogen atoms, cyano, amino, hydroxyl, etc. However, from the perspective of defoaming and economy, all R groups are preferred. 5 More than 80%, particularly preferably more than 90%, of the methyl group is present. Furthermore, n is a positive number of 2.0 ≤ n ≤ 3.2, preferably a positive number of 2.5 ≤ n ≤ 2.9.

[0069] The amount of organopolysiloxane resin used is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 15 parts by weight, and particularly preferably 1.0 to 10 parts by weight, relative to 100 parts by weight of (a) organopolysiloxane. When the amount added is less than 0.1 parts by weight, the effect of improving the persistence of alkaline foaming liquid cannot be obtained; when the amount added is greater than 15 parts by weight, the viscosity of the oil complex used as a defoamer becomes very high, which may sometimes impair workability.

[0070] Here, we will describe the organopolysiloxane-silica crosslinks and their particle size distribution.

[0071] The silicone oil composite for defoaming agents of the present invention (A) is a cross-linked product of (a) organopolysiloxane and (b) micronized silica, and contains an organopolysiloxane-silica cross-link. Further, when using an organopolysiloxane resin (c), it is a cross-linked product of components (a), (b), and (c), and contains an organopolysiloxane-silica cross-link.

[0072] The principle of defoamer action is explained as follows: the defoamer component exists in an insoluble state relative to the foaming liquid. This defoamer component penetrates the bubble film, and the defoamer component, with its lower interfacial tension than the foaming liquid, expands and is torn, creating defects in the bubble film, thus breaking the bubble. Here, while organopolysiloxanes possess excellent properties as defoamer components, such as insolubility in various solvents, primarily water, and low interfacial tension, they also have the weakness of easily undergoing cleavage of siloxane bonds (-O-Si-O) under extreme pH conditions, especially in alkaline environments. As the organopolysiloxane decomposes, its insolubility is impaired, resulting in a gradual decrease in defoaming performance over time. Therefore, although methods to improve the gradual decrease in defoaming performance by further increasing the degree of polymerization of organopolysiloxanes are employed, excessively increasing the degree of polymerization results in very high viscosity, limiting workability. Therefore, by introducing R into the organopolysiloxane... ’ SiO 3 / 2 (T) unit, SiO 4 / 2 (Q) Units such as crosslinking points, or containing R 1 R 2 R 3 SiO 1 / 2 (M) unit and SiO 4 / 2 (Q) unit (c) organopolysiloxane resin, which can suppress the increase of viscosity to some extent while improving the insolubility of organopolysiloxane.

[0073] In addition, in this invention, micro-powdered silica is used, and micro-powdered silica and organopolysiloxane are chemically bonded to generate organopolysiloxane-silica crosslinks. When used as a defoamer, it can not only improve the insolubility in solvents, but also significantly improve the defoaming properties by penetrating the bubble film.

[0074] However, if crosslinking points are introduced as described above to generate organopolysiloxane-silica crosslinks, their large size, especially in the case of self-emulsifying or emulsion-type formations, leads to impaired emulsion stability due to coarse particles. This results in reduced emulsion separation or dispersibility, and consequently, decreased defoaming properties. Regarding the evaluation of organopolysiloxane-silica crosslinks that balance defoaming and emulsion stability in silicone oil composites used as defoamers, no useful analytical methods have been found. Currently, the only reliable approach is to infer their defoaming and defoaming properties during emulsification.

[0075] As a solution to this problem, this invention has found that for (A), a silicone oil composite used as an antifoaming agent, which is a cross-linked product of (a) organopolysiloxane and (b) micronized silica, a particle count method is suitable for determining the particle number of a substance obtained by diluting the organopolysiloxane-silica cross-linked product with toluene using single-particle optical sizing (SPOS) technology. Specifically, by adjusting the particle size distribution of the organopolysiloxane-silica cross-linked product to a median particle size of 5–25 μm (volume standard), preferably 5–23 μm, and more preferably 5–20 μm, it is possible to exhibit initial defoaming properties, particularly persistent defoaming in alkaline foaming solutions, while also maintaining emulsification stability when prepared as an emulsion. If the value is below the lower limit mentioned above, the dispersibility increases, contrary to the condition that the defoamer exists in a state that is insoluble relative to the foaming liquid in order to exhibit defoaming properties. Therefore, the defoaming property decreases, or it is more susceptible to deterioration over time in alkaline foaming liquids. If the value is above the upper limit mentioned above, in the case of forming a self-emulsifying or emulsion type, the coarse particles impair the emulsion stability. Due to the reduced separation or dispersibility of the emulsion, the defoaming property itself also decreases.

[0076] On the other hand, particle size distributions obtained by other particle size distribution determination methods, such as photon correlation (dynamic light scattering, DLS) and laser diffraction / scattering (static light scattering, SLS), differ from particle number counting formulas. In these calculations, the particle size distribution of organopolysiloxane-silica crosslinks is not obtained; only the particle size distribution of silica alone is obtained. Therefore, the correlation between the particle size distribution of silicone oil composites used as defoamers and emulsification stability and defoaming persistence during emulsification has not been established.

[0077] <(A) Preparation of silicone oil composites for defoamers>

[0078] The preparation of the silicone oil composite for defoamers according to (A) of the present invention can be achieved, for example, by mixing the above-mentioned (a) organopolysiloxane and (b) micronized silica, heating at a temperature of 80°C or higher, particularly 80–200°C, and then neutralizing and / or removing low-boiling fractions as needed, thereby enabling it to be manufactured as a crosslinked product. When (c) organopolysiloxane resin is added, for example, by mixing (a) organopolysiloxane and (c) organopolysiloxane resin, mixing under reduced pressure of 10 mmHg or lower at 150°C for 2 hours while distilling off the solvent components, returning to room temperature, mixing (b) micronized silica, heating at a temperature of 80°C or higher, particularly 80–200°C, and then neutralizing and / or removing low-boiling fractions as needed, thereby enabling it to be manufactured as a crosslinked product. To improve the defoaming persistence, high-temperature characteristics, dilution stability, and alkali resistance of the defoamer, inorganic ammonium salts, organosilicon compounds, siloxane resins, and alkaline catalysts, as described in Japanese Patent Application Publication Nos. 4-42043, 5-261206, and 2005-324140, can be added to the silicone oil composite. Although the silicone oil composite for defoamer in (A) of the present invention is a crosslinked product of (a) organopolysiloxane and (b) micronized silica, or (a), (b), and (c) organopolysiloxane resin, the crosslinked product is preferably treated with an alkaline catalyst. Under the condition of adding an alkaline catalyst, a neutralizing agent can be added after this treatment to carry out a neutralization reaction as needed. Furthermore, neutralizing salts can be removed by a filtration step.

[0079] Adjustments to set the specific median particle size range of the organopolysiloxane-silica crosslink within the scope of the present invention can be made, for example, by pre-dispersing (a) the organopolysiloxane and (b) micro-powdered silica having the specific median particle size range using a disperser or kneader.

[0080] In a preferred method for manufacturing the silicone oil composite for defoaming according to the present invention, there are steps of mixing component (b) with component (a) and heating the mixture for crosslinking treatment, wherein the mixing step includes a dispersion step of component (b) into component (a), thereby adjusting the median particle size of the organopolysiloxane-silica crosslink to 5-25 μm.

[0081] In the mixing step, to control the median particle size of the organopolysiloxane-silica crosslinker within a given range, it is preferable to perform a dispersion step by applying a shear rate of 2.75 to 15.8 m / s using a disperser. Here, the circumferential speed is calculated by the following formula.

[0082] ν=(N / 60)·πD

[0083] ν: Circumferential speed (m / s), N: Rotational speed (rpm), D: Blade diameter (m)

[0084] Alternatively, the dispersion step can be carried out by using a kneader to mix component (b) with 1 / 3 to 1 / 5 of the amount of component (a), stirring at 15 to 30 rpm, and then diluting the remaining amount of component (a).

[0085] It should be noted that the above treatment time is preferably 10 minutes to 5 hours, and particularly preferably 1 to 3 hours. Furthermore, the above treatment is preferably carried out under an inert atmosphere such as nitrogen.

[0086] Examples of alkaline catalysts include known alkaline catalysts used in the rearrangement reaction of polysiloxanes, oxides of alkali metals or alkaline earth metals, hydroxides of alkali metals or alkaline earth metals, alkali metals or alkaline earth metals alkoxides or silicates, TMAH (tetramethylammonium hydroxide) silicate catalysts, etc., with potassium silicate and potassium hydroxide being preferred.

[0087] The amount of alkaline catalyst used relative to 100 parts by weight of (a) organopolysiloxane is 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight, and more preferably 0.05 to 2 parts by weight. If the amount of alkaline catalyst used is less than 0.001 parts by weight, the effect as a catalyst may be weak; however, even if the amount used exceeds 5 parts by weight, the effect of the catalyst will not be significantly improved, which may be disadvantageous in terms of cost.

[0088] When manufacturing the silicone oil composite for defoaming agent of the present invention, various types of mixing machines can be used for mixing, such as grid mixers, kneaders, pressure kneaders, twin-shaft mixers, and high-intensity mixers, but there are no particular limitations on them. These mixing machines can be used in any step, such as the mixing process of components (a) and (b), the surface treatment of silica, and the subsequent neutralization step.

[0089] <Defoaming Composition>

[0090] The silicone oil complex (A) obtained in the above steps, used as an antifoaming agent, can be used directly or as an antifoaming composition containing the silicone oil complex. Specifically, it can be used as an antifoaming composition containing (B) an alkylene oxide-modified organopolysiloxane and (C) a surfactant and / or (D) an alkylene oxide polymer, etc., as a silicone oil complex and an emulsifier or emulsification aid. More specifically, (A) the silicone oil complex can be used as a self-emulsifying antifoaming composition obtained by combining it with (B) an alkylene oxide-modified organopolysiloxane, as an emulsion-type antifoaming composition containing (E) water and obtained by known emulsification techniques, or as a solution-type antifoaming composition dispersed in a suitable solvent.

[0091] As (B) organopolysiloxanes modified with polyoxyalkylene oxides, organopolysiloxanes represented by the following general formula (III) can be listed.

[0092] R 6 2R 7 SiO-(R 6 2SiO) x -(R 6 R 7 SiO) y -SiR 6 2R 8 (III)

[0093] In the above general formula (III), R 6 These are monovalent hydrocarbon groups with 1 to 18 carbon atoms that are either identical or different from each other, either substituted or unsubstituted. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, and octadecyl; cyclohexyl groups such as cyclohexyl; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl and tolyl; aralkyl groups such as styryl and α-methylstyryl; or monovalent hydrocarbon groups such as chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, cyanoethyl, 3-aminopropyl, and N-(β-aminoethyl)-γ-aminopropyl, where some or all of the hydrogen atoms bonded to the carbon atoms of these groups are replaced by halogen atoms, cyano, amino, etc.

[0094] In the above general formula (III), R 7 It is a polyoxyalkylene oxide represented by the following general formula (IV).

[0095] -R 9 -O(CH2CH2O) a -(CH2(CH3)CHO) b -R 10 (IV)

[0096] In equation (IV) above, R 9 These are divalent hydrocarbon groups with 2 to 6 carbon atoms, and examples include alkylene and alkenylene groups. Examples include ethylene, propyleneene, trimethylene, butylene, pentylene, and hexylene. Additionally, R... 10 It is a hydrogen atom, an alkyl group, an acetyl group, or an isocyanate group with 1 to 6 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, butyl, and pentyl. a and b are positive numbers that satisfy 3 ≤ a + b ≤ 80, preferably 5 ≤ a + b ≤ 60 and a / b = 2 / 8 to 8 / 2, and more preferably a / b = 2.5 / 7.5 to 7.5 / 2.5.

[0097] In the above general formula (III), R 8 To be with R 6 Or R 7 The same group, hydroxyl group, or alkoxy group having 1 to 6 carbon atoms, specifically, examples can be listed as the R group. 6 and R 7 The exemplified groups include methoxy, ethoxy, propoxy, butoxy, etc., which are alkoxy groups.

[0098] In the above general formula (III), x is an integer from 5 to 200, preferably an integer from 20 to 150, and y is an integer from 1 to 30, preferably an integer from 1 to 20.

[0099] (B) The polyoxyalkylene-modified organopolysiloxane can be used alone or in a mixture of two or more types. The polyoxyalkylene-modified organopolysiloxane should preferably have a viscosity of 10–10000 mmHg, as measured by an Ostwald viscometer at 25°C. 2 / s, more preferably 50 to 8000 mm 2 / s, further preferably 500-5000mm 2 / s of organopolysiloxanes modified with polyoxyalkylene oxides.

[0100] As specific examples of organopolysiloxanes modified with polyoxyalkylene oxides (B), the following organopolysiloxanes can be listed, but are not limited thereto.

[0101] (CH3)3SiO-[(CH3)2SiO] 30 -[(CH3)R'SiO]5-Si(CH3)3

[0102] R': -C3H6O-(C2H4O) 30 -(CH2(CH3)CHO) 10 -C4H9(CH3)3SiO-[(CH3)2SiO] 30-[(CH3)R'SiO]3-Si(CH3)3

[0103] R': -C3H6O-(C2H4O) 20 -(CH2(CH3)CHO) 20 -C4H9(CH3)3SiO-[(CH3)2SiO] 40 -[(CH3)R'SiO]4-Si(CH3)3

[0104] R': -C3H6O-(C2H4O) 21 -(CH2(CH3)CHO)7-COCH3(CH3)3SiO-[(CH3)2SiO] 50 -[(CH3)R”SiO]6-[(CH3)R”'SiO]1-Si(CH3)3

[0105] R”:-C3H6O-(C2H4O) 32 -(CH2(CH3)CHO)8-C4H9

[0106] R”':-C 12 H 25 (CH3)3SiO-[(CH3)2SiO] 135 -[(CH3)R'SiO] 15 -Si(CH3)3

[0107] R': -C3H6O-(C2H4O) 21 -(CH2(CH3)CHO) 21 -CH3(CH3)3SiO-[(CH3)2SiO] 30 -[(CH3)R'SiO]5-Si(CH3)3

[0108] R': -C3H6O-(C2H4O) 25.5 -(CH2(CH3)CHO) 8.5 -C4H9(CH3)3SiO-[(CH3)2SiO] 27 -[(CH3)R'SiO]3-Si(CH3)3

[0109] R': -C3H6O-(C2H4O) 23 -(CH2(CH3)CHO) 23 -C4H9

[0110] As (C) surfactants, examples include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0111] (C-1) Nonionic surfactant

[0112] Examples of nonionic surfactants include, for instance, polyoxyalkylene alkyl ethers or polyoxyalkylene alkenyl ethers having straight-chain or branched alkyl or alkenyl groups with an average carbon number of 10 to 24 and having been added to ethylene oxide, propylene oxide, or butyl oxide; glycerol esters of fatty acids having 8 to 20 carbon atoms; diol esters of fatty acids having 8 to 20 carbon atoms; alkylene oxide adducts of monoglycerides of fatty acids having 8 to 20 carbon atoms; and sucrose of fatty acids having 8 to 20 carbon atoms. Esters; sorbitan anhydride esters of fatty acids having 8 to 20 carbon atoms; polyglycerol fatty acid esters with acyl groups having 8 to 20 carbon atoms; monoethanolamides or diethanolamides or their ethoxylated derivatives of fatty acids having 8 to 20 carbon atoms; polyoxyalkylene hydrogenated castor oil; polyoxyalkylene sorbitan fatty acid esters with acyl groups having 8 to 20 carbon atoms; polyoxyethylene sorbitol fatty acid esters with acyl groups having 8 to 20 carbon atoms; linear esters with 8 to 18 carbon atoms. Alkyl or branched alkyl, alkyl sugar surfactants having alkenyl or alkylphenyl groups; straight-chain alkyl or branched alkyl groups with 8 to 20 carbon atoms, alkylamine oxides or alkylamide amine oxides having alkenyl groups; ether or ester compounds of polyols having straight-chain or branched alkyl or alkenyl groups with 8 to 20 carbon atoms; polyoxyalkylene-modified organopolysiloxanes, polyoxyalkylene / alkyl co-modified organopolysiloxanes, polyglycerol-modified organopolysiloxanes, polyglycerol / alkyl co-modified organopolysiloxanes, polyoxyalkylene / fluoroalkyl co-modified organopolysiloxanes, cross-linked polyoxyalkylene / organopolysiloxanes, sugar-modified organosilicon, oxazoline-modified organosilicon, polyoxyalkylene alkyl aryl ethers, polyoxyalkylene lanolin alcohol, polyoxyalkylene fatty acid esters, Pluronic block polymers, Tetronic block polymers, polyoxyalkylene fatty acid amides, polyoxyalkylene alkylamides, polyethyleneimine derivatives, etc. They can be used individually or in combination with two or more.

[0113] (C-2) Anionic surfactants

[0114] Examples of anionic surfactants include alkylbenzene sulfonates, alkyl ether sulfates or alkenyl ether sulfates, alkyl sulfates or alkenyl sulfates, olefin sulfonates, alkane sulfonates, higher fatty acid salts, (amide) ether carboxylic acid surfactants, α-sulfonyl fatty acid salts or α-sulfonyl fatty acid esters, N-acyl amino acid surfactants, phosphate ester surfactants, sulfosuccinate surfactants, polyoxyalkylene fatty acid amide ether sulfates, monoglyceride sulfates, acylated hydroxyethyl sulfonates, alkyl glycerol ether sulfates or alkyl glycerol ether sulfonates, alkylamide sulfonates or alkenylamide sulfonates, alkanolamide sulfosuccinates, alkyl sulfonyl acetates, acylated taurine esters, and N-acyl-N-carboxyethyl glycine salts. They can be used alone or in combination of two or more.

[0115] Salts of these anionic surfactants, i.e., anti-charged ions of anionic residues, can be exemplified by, for example, alkali metal ions such as sodium and potassium; alkaline earth metal ions such as calcium and magnesium; ammonium ions; and alkanolamines having 1 to 3 alkanol groups with 2 or 3 carbon atoms (e.g., monoethanolamine, diethanolamine, triethanolamine, triisopropanolamine, etc.). They can be used alone or in combination of two or more.

[0116] (C-3) Cationic surfactants

[0117] Examples of cationic surfactants include tertiary amines, quaternary ammonium salts, amide amines, and ester amines. For instance, besides dodecyltrimethylammonium chloride, di(octadecyl)dimethylammonium chloride, hexadecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, N-octadecyl-N,N,N-tris(polyoxyethylene)ammonium chloride (addition total 3 moles of ethylene oxide), hexadecylbenzyldimethylammonium chloride, hexadecyltriethylammonium bromide, and di(octadecyl)dimethylammonium chloride, other examples include 2-decyltetradecyltrimethylammonium chloride, 2-dodecylhexadecyltrimethylammonium chloride, di-2-hexyldecyldimethylammonium chloride, di-2-octyldodecyldimethylammonium chloride, dodecyl tertiary amine, octadecyl tertiary amine, and stearamide propyl dimethylamine. These can be used alone or in combination of two or more.

[0118] (C-4) Amphoteric surfactants

[0119] Examples of amphoteric surfactants include amide-amino acid type, carboxyl betaine type, amide-betaine type, sulfo-betaine type, amide-sulfo-betaine type, imidazoline betaine type, amino acid type, phosphate-betaine type, and phosphate ester type. They can be used individually or in combination of two or more types.

[0120] Examples of (D) polyoxyalkylene polymers include, for example, polyoxyalkylene polymers represented by the following formula.

[0121] HO-[CH2(CH3)CHO] 35 -H

[0122] HO-[CH2(CH3)CHO] 70 -H

[0123] HO-(CH2CH2O)4-[CH2(CH3)CHO] 30 -H

[0124] HO-(C2H4O) 25 -(C3H6O) 35 -H

[0125] HO-(C3H6O) 30 -H

[0126] CH2=CHCH2O-(CH2CH2O) 32 -[CH2(CH3)CHO]8-H

[0127] CH2=CHCH2O-(CH2CH2O) 22 -[CH2(CH3)CHO] 22 -C4H9

[0128] CH2=CHCH2O-(CH2CH2O) 10 -CH3

[0129] It should be noted that the above-described composition is an example and does not limit the present invention.

[0130] (Self-emulsifying defoamer composition)

[0131] The self-emulsifying defoamer composition contains (A) a silicone oil complex for defoaming and (B) an organopolysiloxane modified with polyoxyalkylene oxide.

[0132] As needed, the self-emulsifying defoamer composition may also contain the surfactant (C) and / or polyoxyalkylene polymer exemplified above.

[0133] Furthermore, in the case of a self-emulsifying defoamer composition, the content of the silicone oil complex used as the defoamer in (A) is preferably 5 to 80% by mass of the total defoamer composition, more preferably 10 to 70% by mass, and even more preferably 20 to 60% by mass. If the content of the silicone oil complex is too low, the defoaming performance of the defoamer composition may sometimes deteriorate; if the content of the silicone oil complex is too high, the main purpose of the self-emulsifying defoamer composition, which is to improve the dispersibility of the oil complex components, may not be achieved.

[0134] In addition, in the self-emulsifying defoamer composition, the amount of (B) polyoxyalkylene-modified organopolysiloxane used is preferably 20% or more by mass of the total defoamer composition, more preferably 30% or more by mass, and even more preferably 40% or more by mass.

[0135] In the self-emulsifying defoamer composition, when combined with (D) polyoxyalkylene polymer and nonionic surfactant, the amount used is preferably 0 to 60% by mass of the total defoamer composition, and particularly preferably 0 to 40% by mass.

[0136] (Emulsion-type defoamer composition)

[0137] The emulsion-type defoamer composition contains (A) a silicone oil complex for defoaming, (C) a surfactant, and (E) water. The emulsion-type defoamer composition can be manufactured using known emulsification techniques. In addition to using the surfactant (C), the emulsifier or emulsifying aid for emulsifying (A) the silicone oil complex for defoaming can also be the aforementioned (B) polyoxyalkylene-modified organopolysiloxane and (D) polyoxyalkylene polymer.

[0138] In the emulsion-type defoamer composition, the surfactant (C) is used to disperse the silicone oil complex (A) in the water (E). It can be used alone or in a mixture of two or more. Its content is preferably 20% by mass or less of the total defoamer composition, more preferably 1 to 10% by mass. If the content exceeds 20% by mass, the viscosity of the defoamer composition may increase, resulting in poor workability.

[0139] In the emulsion-type defoamer composition, the above-mentioned (B) polyoxyalkylene-modified organopolysiloxane can be used alone or in a mixture of two or more. Its content is preferably 0-30% by mass of the total defoamer composition, more preferably 1-20% by mass. If the content exceeds 30% by mass, the defoaming performance of the composition may sometimes deteriorate.

[0140] Furthermore, in emulsion-type defoamer compositions, the aforementioned (D) polyoxyalkylene polymer serves as an emulsifying aid. It can be used alone or in a mixture of two or more types, and its content is preferably 0-40% by mass of the total defoamer composition, more preferably 0-20% by mass. If the content of the (D) polyoxyalkylene polymer exceeds 40% by mass, the emulsifying properties of the composition may sometimes deteriorate. It should be noted that although an effective amount can be set in the case of compounding, it is preferably 5% by mass or more of the total defoamer composition.

[0141] In the emulsion-type defoamer composition, the total amount of the emulsifier or emulsifying aid, such as (B) polyoxyalkylene modified organopolysiloxane, (D) polyoxyalkylene polymer and (C) surfactant, is preferably 1 to 40% by mass of the total defoamer composition, more preferably 2 to 20% by mass.

[0142] Furthermore, in the case of an emulsion-type defoamer composition, the content of the silicone oil complex (A) used as the defoamer is preferably 5 to 50% by mass, more preferably 5 to 40% by mass, and particularly preferably 5 to 30% by mass of the total remaining portion of the defoamer composition excluding water (E). If the content of the silicone oil complex is too low, the defoaming performance of the defoamer composition may sometimes deteriorate; if the content of the silicone oil complex is too high, the viscosity of the defoamer composition may sometimes increase, resulting in poor workability.

[0143] In the emulsion-type defoamer composition, water (E) is required to emulsify (A) the silicone oil complex used as a defoamer, (C) the surfactant, (B) the polyoxyalkylene-modified organopolysiloxane, and (D) the polyoxyalkylene polymer. The amount of water (E) added is the balance relative to the total content ratio of each component; preferably, it is added in the form of 50 to 2000 parts by mass, more preferably 80 to 400 parts by mass, relative to 100 parts by mass of the total components.

[0144] It should be noted that although the emulsion-type defoamer composition can be prepared by mixing the components other than water in a given amount, heating as needed, and stirring / emulsifying using known methods, such as using a homogenizer, homogenizer, colloid mill, or other mixer / disperser, it is particularly preferred to prepare the composition by uniformly mixing / dispersing the given amounts of the components other than water, then adding a portion of the amount of water to be added, stirring / emulsifying, and then adding the remaining water, and then uniformly stirring / mixing.

[0145] In addition, for the purpose of preservation, a small amount of preservative or bactericide may be added to the emulsion-type defoamer composition; for the purpose of thickening and emulsion stabilization, a small amount of thickener or other ingredients may also be added.

[0146] Specific examples of the aforementioned preservatives or bactericides include sodium hypochlorite, sorbic acid, potassium sorbate, salicylic acid, sodium salicylate, benzoic acid, sodium benzoate, parabens, and isothiazolino compounds. The amount of preservative or bactericide added is preferably 0 to 0.5% by mass of the total emulsion-type defoamer composition, and particularly preferably 0.005 to 0.5% by mass of the total emulsion-type defoamer composition.

[0147] Specific examples of the aforementioned thickeners include polyacrylic acid, sodium polyacrylate, acrylic acid / methacrylic acid copolymer, sodium carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, xanthan gum, and guar gum. The amount of thickener added is preferably 0 to 1.0% by mass of the total emulsion-type defoamer composition, and particularly preferably 0.01 to 0.5% by mass of the total emulsion-type defoamer composition.

[0148] (Solution-type defoamer composition)

[0149] The solution-type defoamer composition is a composition in which the silicone oil complex (A) used as a defoamer is dispersed in a suitable solvent. The content of the silicone oil complex (A) used as a defoamer in the solution-type defoamer composition is preferably 5-80% by mass of the total defoamer composition, more preferably 30-70% by mass. If the content of the silicone oil complex is too low, the defoaming performance of the defoamer composition may sometimes deteriorate; if the content of the silicone oil complex is too high, the main purpose of the solution-type defoamer composition—to improve the dispersibility of the oil complex component—may not be achieved.

[0150] In addition, solvents that can dissolve hydrophobic organopolysiloxanes as component (a) in solution-type defoamer compositions can be listed as solvents, such as toluene, xylene, hexane, chloroform, 2-butanone, 4-methyl-2-pentanone, etc. They can be used alone or in combination of two or more.

[0151] Example

[0152] The following examples and comparative examples illustrate the present invention in detail, but the present invention is not limited to the following examples. It should be noted that in the examples below, the viscosity is the value measured by an Ostwald viscometer at 25°C.

[0153] (Ingredients list)

[0154] (a) Organopolysiloxane

[0155] (a-1) As a hydrophobic organopolysiloxane, it has a viscosity of 10000 mm. 2 / s of dimethyl polysiloxane [manufactured by Shin-Etsu Chemical Co., Ltd., Japan, KF96 (10000cs)]

[0156] (a-2) As a hydrophobic organopolysiloxane, it has a viscosity of 1000 mm. 2 / s of dimethyl polysiloxane [manufactured by Shin-Etsu Chemical Co., Ltd., Japan, KF96 (1000cs)]

[0157] (a-3) As a hydrophobic organopolysiloxane, it has a viscosity of 8000 mm. 2 / s and contains 0.01 mole fraction of CH3SiO 3 / 2 Branched dimethyl polysiloxane unit

[0158] (b) Micronized silica powder

[0159] (b-1) AEROSIL 300 [manufactured by NIPPON AEROSIL CO.,LTD., with a specific surface area of ​​300 m² as determined by the BET method] was prepared using hexamethyldisilazane. 2 / g, median particle size of the volume standard determined by the SPOS method is 3.3μm] hydrophobic silica with surface treatment.

[0160] (b-2) SIPERNAT D10 [manufactured by Evonik Japan Co., Ltd., median particle size of volume standard measured by SPOS method: 5.5 μm]

[0161] (c) Organopolysiloxane resins

[0162] (c-1) Contains Me3SiO 1 / 2 unit and SiO 4 / 2 The unit is an organopolysiloxane, Me3SiO 1 / 2 Unit / SiO 4 / 2 A 60% toluene solution with a unit concentration of 0.74 (solution viscosity: 10.4 mm). 2 / s)

[0163] (c-2) Contains Me3SiO 1 / 2 unit and SiO 4 / 2 The unit is an organopolysiloxane, Me3SiO 1 / 2 Unit / SiO 4 / 2 A 70% toluene solution with a unit concentration of 1.17 (solution viscosity: 23.1 mm). 2 / s)

[0164] (c-3) contains Me3SiO 1 / 2 unit and SiO 4 / 2 The unit is an organopolysiloxane, Me3SiO 1 / 2 Unit / SiO4 / 2 Unit = 1.30 of 70% toluene solution (solution viscosity: 12.6 mm) 2 / s)

[0165] (B) Organopolysiloxanes modified with polyoxyalkylene oxides

[0166] (B-1) The average composition is expressed by the following formula (V) and the viscosity is 1640 mm. 2 / s of polyoxyalkylene-modified organopolysiloxanes

[0167] R 11 2R 12 SiO-(R 11 2SiO) m -(R 12 R 13 SiO) n -SiR 11 2R 12 (V)

[0168] (In the formula, R) 11 and R 12 For -CH3, R 13 It is -C3H6O(CH2CH2O) 23 (CH2CH(CH3)O) 23 (C4H9, m = 27, n = 3)

[0169] (B-2) The average composition is expressed by the following formula (VI), and the viscosity is 1100 mm. 2 / s of polyoxyalkylene-modified organopolysiloxanes

[0170] R 14 2R 15 SiO-(R 14 2SiO) x -(R 14 R 16 SiO) y -SiR 14 2R 15 (VI)

[0171] (In the formula, R) 14 For -CH3, R 15 -C 13 H 27 R 16 It is -C3H6O(C2H4O)6(C3H6O) 24 CH3, x is 80, y is 2)

[0172] (C) Surfactants

[0173] (C-1) Sorbitan monostearate

[0174] (C-2) Polyethylene glycol monostearate (EO addition molar number 50)

[0175] (D) Polyoxyalkylene polymers with average composition represented by formula (VII)

[0176] HO-(C3H6O) 35 -H(VII)

[0177] (E) Water

[0178] [Examples 1-8]

[0179] (A) Preparation of silicone oil composite

[0180] (a) organopolysiloxane and (b) micronized silica were mixed in the proportions listed in Table 1, and 1 part by mass of potassium silicate containing 3% by mass potassium hydroxide was used as an alkaline catalyst. The mixture was kneaded for 3 hours at 150°C using a grid mixer under a nitrogen atmosphere. After cooling to below 100°C, the mixture was neutralized with 2-chloroethanol, followed by removal of low-boiling fractions to obtain (A) a silicone oil composite.

[0181] To adjust the median particle size of the organopolysiloxane-silica crosslink, prior to the aforementioned heat treatment, conditions were controlled at a blade diameter of [missing information - likely a specific particle size range]. This was achieved by using a disperser (LABOLUTION, manufactured by PRIMIX Co., Ltd., Japan) which functions as a mixer. Mixing is performed at a rotational speed of 1500–5500 rpm (circumferential speed 2.75–15.8 m / s) to promote the dispersion of component (b) into component (a). Alternatively, a kneader (manufactured by Satake Chemical Machinery Co., Ltd., Japan) is used as a mixer, and component (b) is mixed with 1 / 3 to 1 / 5 of the amount of component (a) and stirred at 15–30 rpm to thicken. The remaining amount of component (a) is then mixed and diluted, thereby promoting the dispersion of component (b) into component (a).

[0182] In addition, when combined with organopolysiloxane (c), organopolysiloxane (a) and organopolysiloxane resin (c) based on solids content were mixed in the amounts specified in Table 1. The mixture was stirred for 2 hours at 150°C under reduced pressure (below 10 mmHg) while simultaneously distilling to remove solvent components. After returning to room temperature, it was then kneaded for 3 hours at 150°C using a grid mixer under a nitrogen atmosphere with (b) micronized silica powder and 1 part by mass of potassium silicate containing 3% by mass potassium hydroxide as an alkaline catalyst. After cooling to below 100°C, it was neutralized with 2-chloroethanol, followed by removal of low-boiling fractions, thus obtaining (A) silicone oil composite.

[0183] [Comparative Examples 1-4]

[0184] In order to adjust the median particle size of the organopolysiloxane-silica crosslinker, except that the step of promoting the dispersion of component (b) into component (a) by a mixer was not performed before the above-mentioned heat treatment, the same steps as in Examples 1 to 8 were performed to obtain (A) silicone oil composite.

[0185] [Examples 1 and Examples 3-8, Comparative Examples 1 and Comparative Examples 3-4]

[0186] Preparation of self-emulsifying defoamer compositions

[0187] Using the formulations described in Table 1, (B) polyoxyalkylene modified organopolysiloxane was incorporated into the (A) silicone oil composite obtained above, and in Example 7, (D) polyoxyalkylene polymer was further incorporated into the (A) silicone oil composite obtained above. By mixing with a homogenizer at room temperature, a self-emulsifying defoamer composition was obtained.

[0188] [Example 2, Comparative Example 2]

[0189] Preparation of emulsion-type defoamer compositions

[0190] Using the formulations described in Table 1, (B) polyoxyalkylene modified organopolysiloxane and (C) surfactant were combined in the (A) silicone oil composite obtained above. By adding (E) water at room temperature and mixing and emulsifying with a homogenizer, an emulsion-type defoamer composition was obtained.

[0191] The performance of the organopolysiloxane-silica crosslinks (silicone oil complexes) or defoamer compositions obtained in Examples 1-8 and Comparative Examples 1-4 was evaluated using the following methods. The results are shown in Table 1.

[0192] [Median Particle Size]

[0193] The particle size distribution of organopolysiloxane-silica crosslinks was determined using the Single Particle Optical Sizing (SPOS) method, as follows.

[0194] 99.95 g of solvent (toluene) was added to 0.050 mg of sample (a silicone oil composite used as an antifoaming agent). After the sample was fully dissolved and dispersed, the particle size distribution was determined using the apparatus described below. The median particle size was calculated from the obtained particle size distribution.

[0195] [Particle size distribution measurement apparatus / conditions]

[0196] • Device: Accusizer SIS (manufactured by Particle Sizing System)

[0197] • Measurement principle: Single Particle Optical Sizing (SPOS method, light scattering / shielding method)

[0198] • Measurement range: 0.5~400μm

[0199] • Sample volume × number of measurements: 20 mL × 3 times (collection time: 120 seconds)

[0200] • Measurement temperature: room temperature

[0201] [Emulsion stability]

[0202] The appearance of the emulsion-type defoamer composition, prepared by the above method and left to stand at room temperature for one day, was visually observed according to the following criteria. Additionally, the appearance of the self-emulsifying defoamer composition, after being emulsified by mixing 70g of pure water with 30g of the self-emulsifying defoamer composition and left to stand at room temperature for one day, was also visually observed according to the following criteria.

[0203] ○: No separation, floating oil, or condensate was observed.

[0204] △: A small amount of separation, floating oil and condensate are observed.

[0205] ×: Significant separation, floating oil, and condensate are observed.

[0206] [Defoaming properties (initial stage)]

[0207] Each defoamer composition was added to a commercially available water-based cutting oil (manufactured by Yushiro Chemical Industry Co., Ltd., Yushiroken FGE234) at a concentration of 0.1% by mass of the active ingredient (excluding water). The resulting substance was diluted 10 times with water and stirred in a 500 mL beaker at 5000 rpm for 1 minute using a homogenizer. The time required from the cessation of stirring to the complete disappearance of bubbles was measured. This was repeated three times, and the defoaming persistence was evaluated based on the change in the time required until the bubbles disappeared.

[0208] [Internal stability added]

[0209] The appearance of the substance after it was stored at 50°C for 7 days, after each defoamer composition was added to the above-mentioned water-based cutting oil at an effective ingredient amount (excluding water) of 0.1% by mass, was visually observed according to the following standards.

[0210] ◎: No floating matter or sediment was observed.

[0211] ○: A small amount of floating matter and sediment may be observed.

[0212] △: Moderate levels of floating matter and sediment are observed.

[0213] ×: A large amount of floating matter and sediment are observed.

[0214] [Defoaming properties (after aging)]

[0215] The aged water-based cutting oil used in the above internal stability test was diluted 10 times with water, and stirred in a 500 mL beaker at 5000 rpm for 1 minute using a homogenizer. The time required from stopping the stirring to the complete disappearance of bubbles was measured.

[0216] Table 1

[0217]

Claims

1. A silicone oil complex (A) for use as an antifoaming agent, comprising a crosslinked product of components (a) and (b) below, wherein, (a) Viscosity of 10~100000 mm at 25°C 2 / s of hydrophobic organopolysiloxane: 100 parts by weight (b) Micronized silica powder: 1-15 parts by weight The characteristic feature is that, in the particle size distribution of the organopolysiloxane-silica crosslinked material obtained by diluting the above-mentioned oil complex with toluene using single-particle optical sizing (SPOS method), the median particle size of the particle size standard based on volume is 5~23µm.

2. The silicone oil composite for defoaming agents according to claim 1, It is a cross-linked product of components (a), (b), and (c), wherein, Component (c) contains R 1 R 2 R 3 SiO 1 / 2 unit and SiO 4 / 2 unit, and relative to SiO 4 / 2 Unit R 1 R 2 R 3 SiO 1 / 2 The unit molar ratio is 0.4~2.0, and the amount is 0.1~15 parts by mass. In the unit, R 1 R 2 and R 3 Each is independently represented as an unsubstituted or substituted monovalent hydrocarbon group with 1 to 18 carbon atoms.

3. The silicone oil composite for defoaming agents according to claim 1, It is a cross-linked product of components (a), (b), and (c), wherein, Component (c) contains R 1 R 2 R 3 SiO 1 / 2 unit and SiO 4 / 2 unit, and relative to SiO 4 / 2 Unit R 1 R 2 R 3 SiO 1 / 2 The unit molar ratio is 0.6~1.0, and the amount is 1.0~10 parts by mass. In the unit, R 1 R 2 and R 3 Each is independently represented as an unsubstituted or substituted monovalent hydrocarbon group with 1 to 18 carbon atoms.

4. The silicone oil composite for defoaming agents according to claim 1, It is a product treated with an alkaline catalyst.

5. The silicone oil complex for defoaming agents according to claim 2 or claim 3, It is a product treated with an alkaline catalyst.

6. A self-emulsifying defoamer composition, It contains (A) the silicone oil complex for defoaming as described in claim 1 and (B) an organopolysiloxane modified with polyoxyalkylene oxide.

7. An emulsion-type defoamer composition, It contains (A) the silicone oil complex for defoaming as described in claim 1, (C) a surfactant and (E) water.

8. A method for manufacturing a silicone oil composite for use as an antifoaming agent, It is a method for manufacturing the silicone oil composite for defoaming agents as described in claim 1, characterized in that, It includes the steps of mixing component (b) with component (a) and heating the mixture to perform a crosslinking treatment. In the mixing step, a step of dispersing component (b) into component (a) is set to adjust the median particle size of the organopolysiloxane-silica crosslink to 5~23µm.

9. The method for manufacturing the silicone oil composite for defoamer according to claim 8, In the mixing step, a dispersion step is performed by applying a shear at a circumferential speed of 2.75~15.8m / s using a disperser.

10. The method for manufacturing the silicone oil composite for defoamer according to claim 8, In the mixing step, a kneader is used for the dispersion step, wherein, Mix component (b) with 1 / 3 to 1 / 5 of the total amount of component (a) and stir at 15 to 30 rpm to thicken. Then mix with the remaining amount of component (a) to dilute.

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