Water-soluble silicone defoamer composition and water-based paint containing the same

Abstract

[Problem] To provide a water-soluble silicone defoamer composition that can be uniformly solubilized in water, achieves volatile organic compound (VOC)-free status as defined by the WHO, and has excellent defoaming properties and storage stability, as well as a water-based paint additive and a water-based paint using the same. [Solution] A water-soluble silicone defoamer composition containing (A) a polyether-modified silicone, a polyglycerin-modified silicone, or a mixture thereof having an average HLB value in the range of 0.5 to 5.0, (B) one or more selected from triethylene glycol mono-n-butyl ether and triethylene glycol butyl methyl ether, and (C) water.

Description

Technology Field

[0001] The present invention relates to a water-soluble silicone defoamer composition and a water-based paint containing the same. The present invention also relates to a defoaming method and a quality maintenance method for a water-based paint characterized by the addition of said water-soluble silicone defoamer composition. Background Technology

[0002] Conventionally, silicone-based defoamers exhibit a defoaming effect with only a small amount of addition compared to non-silicone defoamers such as alcohol-based, ester-based, mineral oil, vegetable oil, and synthetic oil. As such, they are widely used as foam breakers and foam inhibitors in fields such as the chemical, food, petroleum, textile, plastics, cement, paint, and adhesive industries, and various compositions have been proposed. In particular, silicone-based defoamers containing polyether-modified silicones such as polyoxyalkylene modifiers, or optionally polypropylene glycol, are liquid and have excellent dispersibility in water. Therefore, by adding or blending the undiluted solution or dispersed (diluted) it into a foaming liquid, the foaming can be effectively suppressed. Consequently, they exhibit excellent handling workability and initial defoaming effects, and are widely used industrially (e.g., Patent Documents 1–5).

[0003] However, even though these silicone-based defoamers are water-dispersible, their use is limited because they do not uniformly solubilize with respect to the aqueous phase, causing suspension of the aqueous phase or a decrease in transparency. Furthermore, Patent Document 6 proposes adding water-soluble polymers such as polyether-modified silicone, polyhydric alcohol alkyl ether, and optionally polyvinyl alcohol to silicone-based defoamers, but when the components disclosed in the document are used, the water dispersibility is improved, and solubilization does not occur. For this reason, there is a strong demand for a water-soluble silicone defoamer composition that can be uniformly solubilized with respect to the aqueous phase and also has excellent defoaming properties and storage stability. Prior art literature

[0004] Patent Document 1: U.S. Patent Publication No. 3233986 Patent Document 2: Japanese Published Patent Application No. (Sho) 54-149388 Patent Document 3: Japanese Published Patent Application No. (Sho) 56-48211 Patent Document 4: Japanese Published Patent Application No. (Sho) 63-147507 Patent Document 5: Japanese Published Patent Application No. (Hei) 07-185212 Patent Document 6: Japanese Published Patent Application No. 2000-246009 The problem to be solved

[0005] In addition to the above problem, the applicant has discovered a new problem regarding the present invention. In silicone-based defoaming agents, low-molecular-weight alcohols such as isopropanol (IPA) are widely used as dispersion media to improve their dispersibility in water and storage stability. However, recently, there has been a strong demand, centered around the World Health Organization (WHO), for so-called VOC-free industrial products that have a low release of low-boiling point or volatile organic compounds, so-called Volatile Organic Compounds (VOC), into the environment. Since IPA, with a boiling point of 82°C, is a volatile organic compound (VOC, boiling point 50–260°C) as defined by the WHO and is also a very volatile organic compound (VVOC, boiling point 100°C or lower), its use is not preferred from the perspective of reducing environmental burden and being eco-friendly. However, alcohols usable as dispersion media for silicone-based defoamers include IPA and are VOCs or VVOCs; as a silicone-based defoamer with excellent water solubilization properties that practically eliminates the need to use these dispersion media has not yet been known, and it has not been possible to provide a silicone-based defoamer product with minimal environmental impact.

[0006] Furthermore, the applicant has discovered a new problem regarding the present invention. In addition to their preservation stability, silicone-based defoamers are generally commercialized by adding preservatives, fungicides, and antimicrobial agents to suppress the growth of live bacteria when incorporated into industrial products such as water-based paints, or into foods and cosmetics, in order to maintain product quality control and safety. However, some preservatives and fungicides contain highly toxic ingredients, so there is a demand for industrial products that use less of them or are free of preservatives and fungicides. On the other hand, no silicone-based defoamer that practically eliminates the need for preservatives and fungicides and has excellent solubilization properties in water has been known until now, and thus, it has not been possible to provide a silicone-based defoamer product that is free of preservatives and fungicides as described above.

[0007] In other words, the objective of the present invention is to provide a water-soluble silicone defoamer composition that can be uniformly solubilized in aqueous solutions, achieves VOC-free status as defined by the WHO, and exhibits excellent defoaming properties and preservation stability. Furthermore, the objective of the present invention is to provide a water-soluble silicone defoamer composition that, if necessary, is free of preservatives and fungicides without compromising preservation stability and quality, and is unlikely to cause problems regarding viable microorganisms even when incorporated into water-based paints.

[0008] Likewise, the object of the present invention is to provide a water-based paint additive and a water-based paint using the above-mentioned water-soluble silicone defoaming agent composition, and also to provide a defoaming method and a quality maintenance method for a water-based paint characterized by the addition of said water-soluble silicone defoaming agent composition. means of solving the problem

[0009] The inventors, after carefully examining the above problem to solve it, discovered that the problem can be solved by a water-soluble silicone defoamer composition comprising one or more selected from triethylene glycol mono-n-butyl ether and triethylene glycol butyl methyl ether, such as a polyether-modified silicone having an average HLB value in a specific range, and water, and arrived at the present invention.

[0010] In detail, the water-soluble silicone defoamer composition of the present invention comprises (A) one or more types of polyether-modified silicone, polyglycerin-modified silicone, or mixtures thereof, having an average HLB value in the range of 0.5 to 5.0; (B) one or more selected from triethylene glycol mono-n-butyl ether and triethylene glycol butyl methyl ether; and (C) water. Here, the above component (B), particularly suitablely triethylene glycol mono-n-butyl ether, is a component that specifically realizes water solubility when used in combination with component (A) and component (C), and at the same time, because it has a boiling point of 260°C or higher, it does not fall under VOCs defined by the WHO, so a VOC-free composition can be designed as needed. Furthermore, by using the above component (B), the proliferation of live bacteria in the composition is strongly inhibited, so a preservative / bactericide-free silicone defoamer composition and a water-based paint containing the same can be designed as needed. In addition, the technical effect cannot be achieved with other similarly structured triethylene glycol alkyl ethers. Effects of the invention

[0011] The water-soluble silicone defoamer composition of the present invention possesses sufficient defoaming properties and storage stability for practical use, and can be uniformly solubilized in aqueous solutions without causing problems such as turbidity or phase separation. Furthermore, the water-soluble silicone defoamer composition of the present invention can achieve volatile organic compound (VOC)-free status as defined by the WHO, and, if necessary, can provide a water-soluble silicone defoamer composition and water-based paints that are free of preservatives and fungicides.

[0012] In addition, the water-soluble silicone defoamer composition of the present invention can provide a water-based paint additive and a water-based paint. Furthermore, a defoaming method and a quality maintenance method for a water-based paint characterized by the addition of said water-soluble silicone defoamer composition can be provided. Specific details for implementing the invention

[0013] The water-soluble silicone defoamer composition of the present invention is described. The composition may further comprise (A) one or more types of polyether-modified silicone, polyglycerin-modified silicone, or a mixture thereof, having an average HLB value in the range of 0.5 to 5.0; (B) one or more selected from triethylene glycol mono-n-butyl ether and triethylene glycol butyl methyl ether; (C) water, and optionally, (D) one or more types of nonionic surfactants having an average HLB value of 2.0 to 12.0 (except for component (A)); (E) hydrophobic silica; (F) an organopolysiloxane having a silanol group at the end of the molecular chain; (G) polypropylene glycol, etc. In addition, the “HLB value” in the water-soluble silicone defoamer composition of the present invention is a calculated value given by Griffin’s formula based on the molecular structure of the subject.

[0014] [Ingredient (A)]

[0015] Component (A) of the present invention is one or more types of polyether-modified silicone, polyglycerin-modified silicone, or a mixture thereof having an average HLB value in the range of 0.5 to 5.0, and is an essential component for solubilizing in water a defoaming component such as a defoaming compound comprising hydrophobic silica and / or an organopolysiloxane having a silanol group at the end of the molecular chain, as described below, by using in combination with component (B) and component (C).

[0016] Component (A) is a silicone compound having a polyether-modifying group represented by at least one polyoxyalkylene group within the molecule or a polyglycerin-modifying group having two or more glycerol units, and is exemplified by one or more selected from polyether-modified silicone, polyglycerin-modified silicone, polyether-polyglycerin co-modified silicone, and mixtures thereof. In addition, the structure of the silicone compound is not particularly limited and may be a linear, branched, dendritic, and cyclic polysiloxane structure, or may have a block copolymer or a cross-linked polysiloxane structure comprising a structure in which two or more polysiloxane structures are connected or cross-linked by a polyoxyalkylene structure or an alkylene structure. Here, the cross-linked polysiloxane structure is exemplified by an organopolysiloxane having a partially cross-linked structure in which a plurality of linear organopolysiloxanes are cross-linked. In terms of water solubilization, component (A) is preferably a straight-chain or branched-chain polydimethylsiloxane having a polyether-modifying group or a polyglycerin-modifying group at the side chain or end, and optionally may have a long-chain alkyl group such as a decyl group, a halogenated alkyl group such as a fluoroalkyl group in the molecule.

[0017] Component (A) is preferably a polyether-modified silicone having polyoxyalkylene groups within the molecule, and -R 1 -O(C2H4O) p (C3H6O) q -R 2 (Here, R 1 R is a divalent hydrocarbon group having 1 to 4 carbon atoms. 2 It is particularly preferable to have a polyoxyalkylene group represented by (where is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and p and q are integers satisfying 10 ≤ p + q ≤ 100 and 10:90 ≤ p:q ≤ 100:0). Hereinafter, the C2H4O unit may be referred to as "EO" and the C3H6O unit as "PO". In addition, R 1 Examples of divalent hydrocarbon groups with 1 to 4 carbon atoms include methylene, ethylene, propylene, and butylene groups, and R2 Examples of alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, and hexyl groups.

[0018] In terms of water solubility, it is necessary for component (A) to have an average HLB value in the range of 0.5 to 5.0. Here, the average HLB value means that if component (A) is one type of polyether-modified silicone, etc., its HLB value is in the range of 0.5 to 5.0, but if component (A) is a mixture of two or more types of polyether-modified silicone, etc., the average value of the individual polyether-modified silicone, etc. according to their mass ratio is in the range of 0.5 to 5.0. That is, when component (A) is a mixture of two or more types of polyether-modified silicone, etc., individual polyether-modified silicone, etc. may have an HLB value of less than 0.5 or greater than 5.0.

[0019] Particularly suitable, component (A) is a polyether-modified silicone or a mixture thereof having an average HLB value in the range of 1.0 to 4.0 (A1), and it is particularly preferable that the average HLB value be in the range of 1.0 to 3.0, 1.1 to 2.5, or 1.2 to 2.0.

[0020] As long as component (A) satisfies the condition of the average value of the above HLB, it is not particularly limited in its molecular weight and viscosity (25°C), but in terms of handling workability and formulation stability in a water-soluble silicone defoamer composition, it is preferable that the kinematic viscosity at 25°C be in the range of 5 to 10,000 mPa·s, and particularly preferable that it be in the range of 100 to 5,000 mPa·s.

[0021] [Ingredient (B)]

[0022] Component (B) of the present invention is one or more selected from triethylene glycol mono-n-butyl ether and triethylene glycol butyl methyl ether, most suitably being triethylene glycol mono-n-butyl ether (sometimes referred to by the trade name “butoxytriglycol” or “butyltriglycol”). Component (B) is a component that enables the solubilization of the silicone defoamer composition of the present invention with water by combining the above component (A) and component (C), which is water. Furthermore, since its boiling point is 260°C or higher, it does not fall under the VOCs defined by the WHO, and thus, if necessary, a VOC-free composition can be designed for the composition according to the present invention. Additionally, since the technical effect cannot be achieved with other triethylene glycol alkyl ethers of similar structure, it is necessary to use at least one of the above two types, most suitably triethylene glycol mono-n-butyl ether.

[0023] In addition, the applicant has also discovered that if one or more selected from triethylene glycol mono-n-butyl ether and triethylene glycol butyl methyl ether are used, the proliferation of viable bacteria is strongly inhibited in the silicone defoamer composition itself and in water-based paints formulated with said composition, making it possible to design a preservative / bactericide-free composition. The same effect, particularly an effect comparable to that of commonly used preservatives, has not been confirmed in other dispersion media.

[0024] [Ingredient (C)]

[0025] Component (C) of the present invention is water, and is a component that forms an aqueous phase in which an antifoaming component, such as an antifoaming compound composed of organopolysiloxane of the composition, an optional nonionic surfactant, and an optional water-soluble component, such as polypropylene glycol, are dispersed. It is also a component that enables the solubilization of the entire silicone antifoaming agent composition of the present invention with water by using it in combination with the above components (A) and (B). In addition, water may include other optional water-soluble components described below.

[0026] It is preferable that the water be clean and not contain components that impair the storage stability of the silicone defoamer composition of the present invention, and examples include ion-exchanged water, distilled water, well water, and tap water. Furthermore, from the perspective of designing a preservative / bactericide-free composition, it is practically preferable that the water be clean water in which the proliferation of microorganisms is suppressed by ozone water, heating, filtration treatment, etc.

[0027] The silicone defoamer composition of the present invention is essential for the above components (A) to (C), and when the total composition is 100 mass%,

[0028] It is preferable that the content of the above component (A) be in the range of 1 to 70 mass%, more preferable that it be in the range of 5 to 50 mass%, and particularly preferable that it be 5 to 30 mass%.

[0029] It is preferable that the content of the above component (B) be in the range of 1 to 50 mass%, more preferable that it be in the range of 5 to 50 mass%, and particularly preferable that it be 5 to 30 mass%.

[0030] It is preferable that the content of the above component (C) be in the range of 1 to 70 mass%, more preferable that it be in the range of 5 to 60 mass%, and particularly preferable that it be 5 to 50 mass%.

[0031] In addition, the silicone defoamer composition of the present invention preferably includes any component other than components (A) to (C).

[0032] [Ingredient (D)]

[0033] The component (D) of the present invention is one or more types of nonionic surfactants having an average HLB value of 2.0 to 12.0, and component (A) is excluded from the range. By using component (D) in combination with component (A), the uniformity and storage stability of the entire composition are further improved, and there is an advantage of further enhancing solubility and dispersibility in water. On the other hand, if the average HLB value of the nonionic surfactant is below the lower limit, there may be cases where solubility in water cannot be sufficiently improved, in particular. Furthermore, if the average HLB value exceeds the upper limit, depending on the combination of the silica component and the organopolysiloxane component described later, the solubility in water and the uniformity of the entire composition may be impaired. In addition, component (D) may include a silicone-based nonionic surfactant such as polyoxyalkylene modified silicone, polyglyceryl modified silicone, glyceryl modified silicone, or sugar modified silicone, provided that it has an average HLB value different from that of component (A); however, for the sake of improving water solubilization, it is particularly preferable that the nonionic surfactant be composed of an organic compound that does not contain siloxane bonds within its molecule. Furthermore, it is preferable that the average HLB value of component (D) be 11 or less, and more preferable that it be in the range of 5 to 11 or 6 to 10.

[0034] As a nonionic surfactant of component (D), polyoxyalkylene ethers, polyoxyalkylene alkyl ethers, polyoxyalkylene fatty acid esters (e.g., those composed of polyethylene glycol (or ethylene oxide) and a higher fatty acid (e.g., a straight-chain or branched fatty acid having 12 to 18 carbon atoms), polyoxyalkylene fatty acid diesters, polyoxyalkylene resin acid esters, polyoxyalkylene (hydrogenated) castor oils, polyoxyalkylene alkyl phenols, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene phenylphenyl ethers, polyoxyalkylene alkyl esters, polyoxyalkylene alkyl esters, sorbitan fatty acid esters, polyoxyalkylene sorbitan alkyl esters (e.g., those composed of sorbitan, polyethylene glycol, and a higher fatty acid (e.g., a straight-chain or branched fatty acid having 12 to 18 carbon atoms), polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene Examples include sorbitate fatty acid esters, polyoxyalkylene glycerin fatty acid esters, polyglycerin alkyl ethers, polyglycerin fatty acid esters, sucrose fatty acid esters, fatty acid alkanolamides, alkyl glucosides, polyoxyalkylene fatty acid bisphenyl ethers, polyoxyethylene-polyoxypropylene block polymers, and alkyl polyoxyethylene-polyoxypropylene block polymer ethers.

[0035] In terms of water solubility, component (D) is preferably a polyoxyalkylene monoalkyl ether or a mixture thereof having an average HLB value of (D1) 11 or less, and the average HLB value may be in the range of 5 to 11 or 6 to 10.

[0036] [Ingredient (E)]

[0037] Component (E) is hydrophobic silica and, together with component (F), is a component that imparts defoaming properties and defoaming persistence. Specifically, examples include fumed silica subjected to hydrophobization treatment, calcined silica fine powder, precipitated silica fine powder, silica aerogel, quartz fine powder, and fused silica fine powder. For the defoaming effect, it is preferable that these hydrophobic silicas have a BET specific surface area of ​​50 m2 / g or more, and particularly preferable that it be 100 m2 / g or more.

[0038] The hydrophobization treatment of component (E) is not particularly limited, but it is common to hydrophobize its surface by mixing it with a hydrophobizing agent represented by component (F), organosilane, and organosiloxane oligomer. Known compounds may be used as organosilane or organosiloxane oligomer, and examples of organosilane include dimethyldichlorosilane, methyltrichlorosilane, hexamethyldisilazane, and dimethyldialkoxysilane. Examples of organosiloxane oligomers include dimethylsiloxane oligomers with bi-terminal silanol group blocking, methylhydrogensiloxane oligomers with bi-terminal trimethylsiloxy group blocking, 1,1,3,3-tetramethyldisiloxane, and 1,3,5,7-tetramethylcyclotetrasiloxane. In addition, other hydrophobic agents include stearic acid, sodium stearate, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(N-2-aminoethyl)aminopropyltrimethoxysilane, etc.

[0039] [Ingredient (F)]

[0040] Component (F) is an organopolysiloxane having a silanol group at the end of the molecular chain, and by mixing it alone or with component (E), a silicone compound can be formed that imparts antifoaming properties and antifoaming persistence to the composition.

[0041] In terms of the antifoaming and water solubilization properties of the composition, component (F) is preferably a dimethylpolysiloxane having silanol groups at both ends of the molecular chain, and optionally may additionally include hydrophobic functional groups such as fluoroalkyl. The kinematic viscosity of component (F) at 25°C is not particularly limited, but may be in the range of 1.5 to 100,000 mPa·s, preferably in the range of 5.0 to 10,000 mPa·s, and more preferably in the range of 5.0 to 5,000 mPa·s. In particular, as component (F) of the present invention, (F1) is preferably exemplified as a dimethylpolysiloxane having silanol groups at both ends of the molecular chain, and its viscosity at 25°C is in the range of 5.0 to 1,000 mPa·s.

[0042] When using a combination of component (E) and component (F) to form and utilize a defoaming silicone compound, it is preferable that the mass ratio of component (F) to component (E) be in the range of 100:1 to 50. This is because if the mass ratio of component (F), which is hydrophobic silica, is less than 1, the expected defoaming properties and defoaming persistence may not be realized, while if the mass ratio of component (F) exceeds 50, it may become difficult to prepare a uniform defoaming agent composition. Furthermore, from the perspective of defoaming properties, it is of course possible to use component (E) or component (F) alone.

[0043] [Ingredients (G)]

[0044] Component (G) is polypropylene glycol and is a component that improves the defoaming properties and defoaming persistence of the entire silicone defoaming agent composition according to the present invention, preferably by using it in combination with the above components (A) to (E). In particular, by using polypropylene glycol as component (G) in combination with component (A) which is triethylene glycol mono-n-butyl ether, a silicone defoaming agent composition can be provided that has excellent uniformity and solubility in water, and further improves the defoaming properties and defoaming persistence.

[0045] The above components (D) to (G) are any components of the present invention, and when the total composition is 100 mass%,

[0046] It is preferable that the content of the above component (D) be in the range of 0 to 40 mass%, more preferable that it be in the range of 5 to 40 mass%, and particularly preferable that it be 5 to 35 mass%.

[0047] It is preferable that the content of the above component (E) be in the range of 0 to 5 mass%, more preferable that it be in the range of 0.1 to 3 mass%, and particularly preferable that it be 0.2 to 2 mass%.

[0048] It is preferable that the content of the above component (F) be in the range of 0 to 10 mass%, more preferable that it be in the range of 0.2 to 8 mass%, and particularly preferable that it be 0.5 to 6 mass%.

[0049] It is preferable that the content of the above component (G) be in the range of 0 to 50 mass%, more preferable that it be in the range of 0 to 30 mass%, and particularly preferable that it be 5 to 25 mass%.

[0050] [Other optional components]

[0051] In the silicone defoaming agent composition of the present invention, other emulsifiers, alcohols, solvents, stabilizers, thickeners, preservatives, pH adjusters, etc. may be incorporated to a range that does not impair the purpose of the present invention. The amount of the defoaming agent composition of the present invention added to a target object during use is determined according to various conditions such as the target process, the properties of the defoaming target object, and the influence on the physical properties of the final product; however, as a general standard, it is preferable to have 1 to 500 ppm in the case of a high-concentration defoaming agent composition with a low water content, and 100 to 10,000 ppm in the case of a low-concentration defoaming agent composition with a high water content.

[0052] Meanwhile, in the silicone defoamer composition of the present invention, by selecting component (B), it is possible to achieve VOC-free as defined by the WHO and simultaneously achieve preservative / bactericide-free. Therefore, when these technical intentions are met, it is particularly desirable not to use low-boiling point alcohols or solvents, and not to use preservatives, etc. For example, in the case of preservative / bactericide-free, the content of the preservative or bacteria component is an amount of 0.05 mass% or less of the total water-based paint containing the silicone defoamer composition, and it is particularly desirable not to substantially contain preservatives or bacteria.

[0053] [Manufacturing Method]

[0054] The silicone defoamer composition of the present invention can be prepared by uniformly stirring the above components (A) to (C) and other components using mechanical force such as a mixer. As long as the device is capable of inputting raw materials and uniform stirring, the stirring / mixing device is not particularly limited, and the temperature conditions during stirring are not particularly limited as long as uniform stirring is possible; for the purpose of reducing viscosity, it may be heated up to about 50°C. In addition, the above components (E) and (F) may be mixed in advance and formulated in the form of a silicone compound, or the water-soluble component (C) may be mixed in advance and then the entire mixture may be uniformly stirred. Furthermore, if necessary, after uniformly stirring each component, it may be further processed using a high-pressure emulsification device capable of applying high shear force, such as a colloid mill, ball mill, disperser mill, homogenizer, or Gaulin homogenizer.

[0055] [use]

[0056] The water-soluble silicone defoamer composition of the present invention is effective against aqueous foaming liquids and can be particularly well used as a defoamer for paints (water-based paints, paper coating paints, etc.) and as a defoamer for various manufacturing processes (papermaking process, fermentation process, wastewater treatment process, monomer stripping process and polymer polymerization process, etc.). By solubilizing it in an aqueous solution, it can achieve excellent defoaming or foam suppression effects while maintaining a transparent to translucent and uniform appearance.

[0057] In particular, the water-soluble silicone defoamer composition of the present invention is suitable as an additive for water-based paints and is also very suitable as a defoamer for water-based paints. Among water-based paints (water-based paints for building exteriors, paints for building interiors, water-based inks and paints for paper coatings, etc.), it is particularly very suitable as a defoamer for emulsion-containing water-based paints and paper coatings. In addition, emulsions used in emulsion paints may include vinyl acetate resin, acrylic resin, styrene resin, halogenated olefin resin, urethane resin, silicone resin, or silicone resin containing fluorine atoms, and it is effective for any of them, and is particularly effective for acrylic paints containing acrylic resin, acrylic styrene paints, acrylic urethane paints, and acrylic silicone paints. In addition, since the water-soluble silicone defoamer composition of the present invention enables uniform solubilization in the aqueous phase, it is effective for all water-based paints including alcohol-based or emulsion-type paints. Unlike conventional emulsion-type silicone defoamers and suspension-type silicone defoamers, because it is uniformly solubilized in the aqueous phase of the paint, it is difficult to affect the stability of the formulation or emulsion, while simultaneously achieving high defoaming or foam suppression performance.

[0058] When applying the water-soluble silicone defoamer composition of the present invention to the water-based paint, the method of adding may be done during pigment dispersion or after paint production, but it is particularly preferable to add it after paint production in which the aqueous phase is a continuous layer. In addition, when applying to various manufacturing processes, the method may be any of the following: (1) together with the supply of raw materials, (2) before heating and / or depressurization treatment, and / or (3) the final finishing process.

[0059] The amount of water-soluble silicone defoamer composition of the present invention added is in the range of 0.01 to 2.0 mass% with respect to the solid content of the water-based paint, converted to solid content, a range of 0.05 to 1.0 mass% is more preferable, and a range of 0.05 to 0.5 mass% is particularly preferable.

[0060] [Antifoaming and Quality Preservation Methods for Water-based Paints]

[0061] The water-soluble silicone defoamer composition of the present invention can achieve a defoaming or anti-foaming effect by being appropriately incorporated into a water-based paint in the above-mentioned amount. Furthermore, as described above, by using component (B), the water-soluble silicone defoamer composition of the present invention itself strongly inhibits the proliferation of live bacteria, and can be used for quality preservation of water-based paints (including antibacterial and anti-spoilage effects), and can realize a composition that is substantially free of preservatives / bactericides for said water-based paints.

[0062] Examples

[0063] The water-soluble silicone defoamer composition of the present invention and the water-based paint containing the same are described in detail by way of examples. In addition, the viscosity is a value measured using a rotational viscometer at 25°C.

[0064] (Appearance and presence of phase separation)

[0065] The appearance and the presence or absence of phase separation were evaluated visually and rated as "transparent" or "turbid."

[0066] In addition, if even slight separation was observed, it was evaluated as "separation present," and if the entire sample was uniform, it was evaluated as "uniform (no phase separation)."

[0067] (Evaluation of antifoaming ability: Evaluation based on liquid level height after stirring and the number of bubbles after 30 seconds)

[0068] 50 g of a coating agent having the following composition was placed in a glass bottle with a diameter of 55 mm, and 0.4 mass% of the silicone defoamer of the present invention or a silicone oil other than the one was added to make a sample. The sample was then stirred for 1 minute at a rotational speed of 5,000 rpm using an edged turbine-type stirring blade, and the antifoaming properties (height of the liquid level after stirring (mm)) were evaluated by measuring the height of the liquid level immediately after stirring stopped.

[0069]

[0070] In addition, the same sample was coated (20 times back and forth) on a 200 mm x 300 mm tin-plated steel plate (tin plate) using a medium-sized roller, and the anti-foaming properties (number of bubbles after 30 seconds) were evaluated based on the number of bubbles (diameter 1.0 mm or larger) within a 10 cm × 15 cm area in the center after 30 seconds.

[0071] (Flatness / uniformity of the coating)

[0072] The above sample was applied to a 150 mm × 50 mm glass plate using Bar Coater #16, and the number of cissing incidents within a 10 cm × 10 cm area of ​​the coated surface was evaluated visually.

[0073] If the number of occurrences of pitting was 5 or fewer, it was evaluated as “good,” and if it was 6 or more, it was evaluated as “poor,” and the number of pitting was recorded.

[0074] (Vivid bacteria test)

[0075] Test bacterial solutions prepared after pre-culture were each inoculated into test samples, and after a certain period of time, the viable cell count was measured and the preservation efficacy was evaluated. The bacterial species were Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, Aspergillus brasiliensis, and Pseudomonas fluoresceinus.

[0076] In addition, for test specimens where a uniform sample was not obtained, a viable cell test was not performed.

[0077] In each example and comparative example, each of the following components was used.

[0078] A-1) Polyether-modified silicon having a polyether structure containing EO units and PO units within the molecule (HLB 1.6, molecular weight 10000, viscosity 650 mPa·s)

[0079] A-2) Polyether-modified silicone having a polyether structure containing only EO units within the molecule (HLB 1.8, molecular weight 5000, viscosity 150 mPa·s)

[0080] Among the following B-1) to B-14), only B-1) and B-14) are components (B) of the present invention used in the examples, and the others are similar compounds and alcohols for comparative experiments.

[0081] B-1) Triethylene glycol mono-n-butyl ether, purity >98%, product of Tokyo Chemical Industry Co., Ltd.

[0082] B-2) Diethylene glycol mono-n-butyl ether, purity >98%, Fujifilm Wako Junyaku Co., Ltd. product

[0083] Others

[0084] B-3) 2-Propanol, Purity > 99.7%, Product of Fujifilm Wako Junyaku Co., Ltd.

[0085] B-4) Dipropylene glycol monomethyl ether, purity >95%, Fujifilm Wako Junyaku Co., Ltd. product

[0086] B-5) Tripropylene Glycol Monobutyl Ether, Purity >95%, Product of Kanto Chemical Co., Inc.

[0087] B-6) Triethylene Glycol, Purity >98%, Alfa Aesar Product

[0088] B-7) Tetraethylene Glycol, Purity >95%, Product of Tokyo Kasei Kogyo Co., Ltd.

[0089] B-8) Tetraethylene Glycol Dimethyl Ether, Purity >98%, Product of Tokyo Kasei Kogyo Co., Ltd.

[0090] B-9) Triethylene glycol dimethyl ether, purity >97%, Fujifilm Wako Junyaku Co., Ltd. product

[0091] B-10) 2-Butoxyethanol / Ethylene Glycol Mono-n-Butyl Ether, Purity >99%, Product of Fujifilm Wako Junyaku Co., Ltd.

[0092] B-11) Triethylene glycol dimethyl ether purity >97%, Fujifilm Wako Junyaku Co., Ltd. product

[0093] B-12) Triethylene glycol monomethyl ether, purity >98%, product of Tokyo Kasei Kogyo Co., Ltd.

[0094] B-13) 2-ethoxyethyl acetate, purity >98%, product of Kanto Kagaku Co., Ltd.

[0095] B-14) Triethylene glycol butyl methyl ether, purity >97%, Fujifilm Wako Junyaku Co., Ltd. product

[0096] C) Water ion exchange water

[0097] D-1) Non-ionic surfactant, Product name SANNONIC SS-30 (Product of Sanyo Chemical Industries, Ltd.) HLB=8

[0098] D-2) Non-ionic surfactant Product name Sannonic SS-50 (Manufactured by Sanyo Kasei Kogyo Co., Ltd.) HLB=10.5

[0099] E) Hydrophobic Silica Trade Name Aerosil R-972 (Product of NIPPON AEROSIL CO., LTD.)

[0100] F) Dimethylpolysiloxane having silanol groups at both ends of the molecular chain (molecular weight 900, viscosity 40 mPa·s)

[0101] G) Polypropylene Glycol, Product Name SANNIX PP-2000 (Manufactured by Sanyo Kasei Kogyo Co., Ltd.)

[0102] [Examples 1–4 and Comparative Examples 1–2]

[0103] The above ingredients were uniformly stirred and mixed using mechanical force (mixer) to achieve the concentration (mass%) listed in Table 1 to adjust the water-solubilizing silicone defoamer, and then left to stand for 24 hours and 1 week. The appearance and presence or absence of phase separation were determined by the above method and recorded in Table 1.

[0104] In addition, 0.4 parts by mass (%) was added to an acrylic emulsion paint (based on U-Double (registered trademark) E-135, Nippon Shokubai Co., Ltd. product), and the mixture was uniformly stirred and mixed using mechanical force (mixer). The anti-foaming performance and other properties were evaluated using the above method and are shown in the table below.

[0105]

[0106] [Comparative Examples 4~13]

[0107] The component B-1) of "Example 1" listed in the table above was replaced with components B-4) to B-13) that do not correspond to component (B) of the present invention, and the water-soluble silicone defoamer was adjusted by uniformly stirring and mixing with mechanical force (mixer) in the same manner as in Example 1, left to stand for 24 hours, and the presence or absence of phase separation was determined and recorded using the above method. As a result, in the comparative examples using B-4) to B-13) that do not correspond to component (B) of the present invention, phase separation occurred in all cases, and a uniform defoamer composition could not be obtained.

[0108] [Example 5]

[0109] The component B-1) of "Example 1" listed in the table above was replaced with component B-14), which is component (B) of the present invention, and a water-solubilizable silicone defoamer was prepared by uniformly stirring and mixing with mechanical force (mixer) in the same manner as in Example 1, left to stand for 24 hours, and the presence or absence of phase separation was determined and recorded by the above method. As a result, when B-14) triethylene glycol butyl methyl ether was used, it was uniformly dispersed, and the composition could be solubilized in water.

[0110] <Overall>

[0111] The water-soluble silicone defoamer according to the example is water-soluble, so it has excellent handling workability and uniform dispersion. When mixed into a water-based paint by simply stirring with a mixer, it becomes a uniform and transparent silicone composition, and does not cause phase separation even after one week. In addition, the composition has excellent defoaming properties, allowing for a uniform coating film to be obtained. Furthermore, it inhibits the proliferation of live bacteria over a long period without the use of preservatives, antibacterial agents, or bactericides, making it antibacterial agent-free and having excellent storage stability. Moreover, all components (B) used in the example do not correspond to volatile organic compounds, thereby realizing a water-soluble silicone defoamer that is free of volatile organic compounds (VOCs) while having the above advantages.

[0112] Meanwhile, in comparative examples that did not use component (B) of the present invention, or used a water-solubilizing agent component that did not correspond to component (B), practical application was difficult because the composition was not dispersed in water and subsequently became cloudy and separated into phases. Furthermore, when these compositions were incorporated into an emulsion paint, the anti-foaming properties were clearly inferior compared to the examples, and at the same time, it caused coating defects such as pitting in the appearance of the coating film. In addition, even when using IPA (2-propanol), which is equivalent to a volatile component (VOC), instead of component (B) of the present invention, technical effects equivalent to those of the present invention could not be realized (Comparative Example 3).

Claims

Claim 1 A water-soluble silicone defoamer composition comprising (A) one or more polyether-modified silicones, polyglycerin-modified silicones, or mixtures thereof, with an average HLB value in the range of 0.5 to 5.0; (B) one or more selected from triethylene glycol mono-n-butyl ether and triethylene glycol butyl methyl ether; (C) water; and (D) one or more nonionic surfactants with an average HLB value of 2.0 to 12.0 (except for component (A)). Claim 2 In claim 1, additionally, (E) a water-soluble silicone defoamer composition containing hydrophobic silica. Claim 3 In paragraph 2, additionally, (F) a water-soluble silicone defoamer composition containing an organopolysiloxane having a silanol group at the end of the molecular chain. Claim 4 ◈Claim 4 was abandoned upon payment of the registration fee.◈ In claim 3, additionally, (G) a water-soluble silicone defoamer composition containing polypropylene glycol. Claim 5 ◈Claim 5 was abandoned upon payment of the registration fee.◈ A water-soluble silicone defoamer composition according to Claim 4, wherein, when the total composition is 100 mass%, the content of component (A) is in the range of 1 to 70 mass%, the content of component (B) is in the range of 1 to 50 mass%, the content of component (C) is in the range of 1 to 70 mass%, the content of component (D) is in the range of 5 to 40 mass%, the content of component (E) is in the range of 0 to 5 mass%, the content of component (F) is in the range of 0 to 10 mass%, and the content of component (G) is in the range of 0 to 50 mass%. Claim 6 ◈Claim 6 was abandoned upon payment of the registration fee.◈ A water-soluble silicone defoamer composition according to any one of claims 1 to 5, wherein the component (A) is a polyether-modified silicone or a mixture thereof having an average HLB value (A1) in the range of 1.0 to 4.0, the content of the component (B) is in the range of 10 to 150 parts by mass per 100 parts by mass of the component (A), and the content of the component (C) is in the range of 1 to 200 parts by mass per 100 parts by mass of the component (A). Claim 7 ◈Claim 7 was abandoned upon payment of the registration fee.◈ A water-soluble silicone defoamer composition according to any one of claims 1 to 5, wherein the component (D) is a polyoxyalkylene monoalkyl ether or a mixture thereof having an average HLB value of (D1) 11 or less. Claim 8 ◈Claim 8 was abandoned upon payment of the registration fee.◈ A water-soluble silicone defoamer composition, which is a water-based paint additive, in any one of Claims 1 to 5. Claim 9 A water-based paint comprising a water-soluble silicone defoamer composition as described in any one of claims 1 to 5. Claim 10 A water-based paint according to claim 9, wherein the content of a preservative or fungicide component is 0.05 mass% or less of the total water-based paint. Claim 11 A method for defoaming water-based paint, comprising the step of adding a water-soluble silicone defoamer composition described in any one of claims 1 to 5 to the solid content of one or more types of water-based paint, wherein the composition is 0.01 to 2.0 mass% in terms of solid content. Claim 12 A method for preserving the quality of a water-based paint, comprising the step of adding a water-soluble silicone defoamer composition described in any one of claims 1 to 5 to the solid content of one or more types of water-based paints, in an amount of 0.01 to 2.0 mass% when converted to solid content. Claim 13 delete

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