JPH0442043B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an antifoam composition, particularly an antifoam composition with improved defoaming durability under strong shear and high temperatures, and a method for producing the same. . [Prior Art] Silicone antifoaming agents made of hydrophobic base oils such as dimethylpolysiloxane and finely powdered silica are well known, and various methods are known to enhance their antifoaming effects. . In other words, for this purpose, for example, a method is known in which the surface silanol groups of fine silica powder are treated with an organic group to make them hydrophobic, thereby providing antifoaming properties even under acidic or alkaline conditions. ) Spraying dimethylsiloxane on silica and treating it at high temperature, 2) Treating silica with organic hydrogen halide, 3) Dispersing silica in silicone oil and treating it at high temperature, diluting it with a solvent and centrifuging it to produce it. The method of drying the solid solid (see Japanese Patent Publication No. 42-26179) is to heat-treat a mixture of polysiloxane liquid and precipitated silica, and then deposit the polysiloxane liquid on the precipitated silica to form hydrophobic silica. The method for producing silica (see Japanese Patent Publication No. 42-22454) is to convert the silanol group on the silica surface to the formula (R′ _{2
A compound represented by} N ₎ ~2, m=1~
40) (see Japanese Patent Publication No. 47-13487) are disclosed in these publications. Further, regarding antifoam compositions containing silica treated with hydrophobic treatment in this way, compositions consisting of silicone oil and silica treated with hydrophobic treatment with dimethyldichlorosilane (see Japanese Patent Publication No. 31836/1983), A composition obtained by adding various basic substances such as potassium silanolate, potassium hydroxide, and trialkylamine to a mixture of organopolysiloxane and finely powdered silica, and heat-treating the mixture to make the silica hydrophobic. 1602), a composition consisting of an organopolysiloxane or hydrocarbon base oil and fine silica powder hydrophobically treated with an organohydrodiene polysiloxane (Japanese Patent Application Laid-Open No. 57-48307)
There is also known a method for reacting this silica with an alkoxy silicone chloride to form a suspension which is particularly stable even in oil (see Japanese Patent Publication No. 13485/1985). [Problems to be solved] However, in all of these known methods, the active silanol on the surface of finely powdered silica is treated with a silicon compound or an organic compound to make it hydrophobic, thereby improving its defoaming performance, acid resistance, and alkali resistance. As a result, the interaction between the organopolysiloxane base oil or hydrocarbon base oil and the hydrophobically treated silica due to the surface properties of the silica is inevitably weakened, and therefore foaming that is subjected to strong shearing is inevitably weakened. In foaming systems and high-temperature foaming systems, the organopolysiloxane base oil or hydrocarbon base oil and hydrophobic silica separate, resulting in a problem that the antifoaming effect does not last for a long time. [Means for Solving the Problems] The present invention relates to an antifoaming agent composition that solves these disadvantages and a method for producing the same, which includes: 1) 100% by weight of a hydrophobic base oil selected from organopolysiloxane oils; 2) 1 to 40 parts by weight of finely powdered silica hydrophobically treated with an organosilicon compound;
3) an antifoaming agent composition characterized by comprising 0.1 to 5 parts by weight of an inorganic ammonium salt compound; The present invention relates to a method for producing an antifoam composition, which is characterized by heat treatment for ~5 hours. That is, the present inventors have conducted various studies on antifoaming compositions that have good antifoaming properties even under strong shearing and high temperatures. It was discovered that when an inorganic ammonium salt compound was added to a composition consisting of After confirming that the defoaming durability under strong shearing and high temperatures was significantly improved, we conducted research on the type and amount of the hydrophobic fine powder silica and the inorganic ammonium salt compound, and completed the present invention. Ta. [Function] These will be explained in detail below. The hydrophobic base oil as the first component constituting the composition of the present invention is said to be selected from organopolysiloxane oils, and this organopolysiloxane has the general formula and R ¹ is an alkyl group such as a methyl group, ethyl group, propyl group, or butyl group, an alkenyl group such as a vinyl group or an allyl group, an aryl group such as a phenyl group or a tolyl group, or a carbon atom of these groups. Part or all of the bonded hydrogen atoms are halogen atoms,
Chloromethyl group substituted with cyano group etc., 3,
Same or different carbon atoms 1 to 20, such as 3,3-trifluoropropyl group, cyanopropyl group, etc.
are selected from unsubstituted or substituted monovalent hydrocarbon groups with an average value of a of 1.9 to 2.1, including dimethylpolysiloxane, diethylpolysiloxane, methylphenylpolysiloxane, polydimethyl- Examples include polydiphenylsiloxane copolymer, polymethyl-3,3,3-trifluoropropylsiloxane, polydimethyl-chloropropylmethylsiloxane, etc., in which the molecular chain terminals are blocked with a trimethylsilyl group or a dimethylhydroxysilyl group. Homopolymers or copolymers of dimethylsiloxane, methylphenylsiloxane, or diphenylsiloxane are preferred, but dimethylpolysiloxane oil is particularly preferred from the viewpoint of antifoaming properties and economic efficiency. The terminal end is usually capped with a trimethylsilyl group, but it may also be capped with a hydroxyl group. Note that these base oils may be liquid at room temperature, but in terms of antifoaming properties and workability, it is necessary to have a viscosity of 20 to 1,000,000 cs at 25°C, which is preferably 50 to 1,000,000 cs. It is recommended that it be in the range of 10000cs. Next, the fine powder silica as the second component constituting the composition of the present invention needs to be hydrophobically treated, but this fine powder silica may be either known dry silica or wet silica. These include Aerosil [trade name manufactured by Nippon Aerosil Co., Ltd.], Nipsil [trade name manufactured by Nippon Silica Co., Ltd.], Thyroid [trade name manufactured by Fuji Davison Co., Ltd.], and Kyabosil [manufactured by Kyabot Corporation of the United States]. Examples include Santocel [product name manufactured by Monsanto Chemical Company in the United States], but the specific surface area according to the BET method is 50 m ² /g.
The above is preferable. The hydrophobic treatment of this fine powdered silica can be carried out by a known method, and therefore, it has the formula (R ² ₃ Si) _b Z
or R ² _b SiZ' _4-b [where R ² is the same or different monovalent hydrocarbon group, Z and Z' are halogen atoms, hydrogen atoms or -OH, -OR ³ , -NR ³ X, -ONR ³ ₂ ,
-SR ³ , -OOCR ³ (R ³ is a monovalent hydrocarbon group, preferably an alkyl group having 1 to 4 carbon atoms,
is hydrogen or the same as R ¹ ), b is 1 or 2], in particular the halogen atoms of Z and Z' are chlorine, and R ³ is an organic group, preferably a methyl group or an ethyl group. The organic silicon compound may be treated with a silicon compound, such as hexamethyldisilazane, trimethylethoxysilane, trimethylsilane, trimethylchlorosilane, dimethyldichlorosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldiethoxysilane. , vinylmethyldimethoxysilane, methyltriethoxysilane, trimethylsilylmercapitane, vinyldimethylacetoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisilazane, trimethylsilylisopropylamine, Examples include trimethylsilylethylamine, phenyldimethylsilylpropylamine, and vinyldimethylsilylbutylamine. This hydrophobic treatment using organosilicon compounds was carried out in the 1970s.
As disclosed in Japanese Patent Publication No. 35556 and Japanese Patent Publication No. 52-31836, the silanol groups on the silica surface are often hydrophobically treated with a nitrogen-containing organosilicon compound or a chlorine-containing organosilicon compound. From the viewpoint of antifoaming performance, it is preferable to use silanol groups on the surface that have been hydrophobically treated with hexamethyldisilazane, 1,3-diphenyltetramethyldisilazane, trimethoxychlorosilane, dimethyldichlorosilane, etc. The reaction between this organosilicon compound and finely powdered silica may be carried out by the known methods described in Japanese Patent Publications No. 47-30422 and Japanese Patent Publication No. 53-44504. If the blending amount of the hydrophobic silica as the second component thus obtained is less than 1 part by weight based on 100 parts by weight of the hydrophobic base oil as the first component, its performance will not be fully exhibited; If the amount is more than 1 part by weight, the viscosity of the base oil will increase, resulting in poor workability and difficulty in handling, so it is necessary to use 1 to 40 parts by weight, preferably 3 to 20 parts by weight. . Furthermore, as described above, the inorganic ammonium salt compound as the third component constituting the composition of the present invention strengthens the bond between the hydrophobic base oil as the first component and the hydrophobic silica as the second component. ammonium chloride.
NH ₄ Cl, ammonium chlorate NH ₄ ClO ₃ , ammonium perchlorate NH ₄ ClO ₄ , ammonium bromide
NH ₄ Br, ammonium bromate NH ₄ BrO ₃ , ammonium iodide NH ₄ I, ammonium iodate
NH ₄ IO ₃ , ammonium fluoride NH ₄ F, ammonium hydrogen fluoride NH ₄ HF ₂ , ammonium carbonate (NH ₄ ) ₂ CO ₃・H ₂ O, ammonium hydrogen carbonate NH ₄
HCO ₃ , ammonium nitrate NH ₄ NO ₃ , hydroxylammonium nitrate (NH ₃ OH) NO ₃ , ammonium sulfide (NH ₄ ) ₂ S, ammonium hydrogen sulfide
NH ₄ SH, ammonium sulfate (NH ₄ ) ₂ SO ₄ , ammonium hydrogen sulfate (NH ₄ )HSO ₄ , ammonium zinc sulfate (NH ₄ ) ₂ Zn(SO ₄ ) ₂・6H ₂ O, ammonium cobalt sulfate (NH ₄ ) ₂ CO( _SO4 ) ₂・_6H2O ,
Iron sulfate () ammonium (NH ₄ ) ₂ Fe (SO ₄ ) ₂・
6H ₂ O, iron sulfate () ammonium (NH ₄ ) Fe
(SO ₄ ) ₂・12H ₂ O, magnesium sulfate (NH ₄ ) ₂ Mg
(SO ₄ ) ₂・6H ₂ O, ammonium phosphate (NH ₄ ) ₃
PO ₄・3H ₂ O, diammonium hydrogen phosphate (NH ₄ ) ₂ HPO ₄ , ammonium dihydrogen phosphate NH ₄
H ₂ PO ₄ , ammonium amidosulfate NH ₄ SO ₃ NH ₂ ,
Ammonium peroxodisulfate (NH ₄ ) ₂ S ₂ O ₈ ,
Ammonium thiosulfate (NH ₄ ) ₂ S ₂ O ₃ , ammonium pentasulfide (NH ₄ ) ₂ S ₅ , ammonium thiocyanate NH ₄ SCN, tetraammonium dihydrogen tricarbonate (NH ₄ ) ₄ H ₂ (CO ₃ ) ₃・H ₂ O, ammonium chromate (NH ₄ ) ₂ CrO ₄ , ammonium dichromate (NH ₄ ) ₂ Cr ₂ O ₇ , ammonium arsenate (NH ₄ ) ₃
AsO ₄ 3H ₂ O, ammonium molybdate (NH ₄ ) ₂ MoO ₄ , ammonium metaborate (NH ₄ )
Examples include BO ₂ .1.25H ₂ O, hexachlorotin ammonium (NH ₄ ) ₂ [SnCl ₆ ], and among these, ammonium chloride, ammonium hydrogen chloride,
Ammonium carbonate, ammonium hydrogen carbonate, ammonium nitrate, ammonium sulfate, ammonium hydrogen sulfate, ammonium phosphate, and diammonium hydrogen phosphate are preferred. If the amount of this inorganic ammonium salt compound is less than 0.1 part by weight based on 100 parts by weight of the hydrophobic base oil as the first component, the desired effect will not be obtained, and if it is more than 5 parts by weight, the effect will be reduced. Since the foaming properties become worse and the ammonium odor becomes stronger, which is undesirable in terms of workability, the amount needs to be 0.1 to 5 parts by weight, but the preferred range is 0.2 to 3 parts by weight. The antifoam composition of the present invention can be obtained by uniformly mixing predetermined amounts of the first to third components described above, but the composition can be manufactured by adding the first to third components. 60 to 200℃ after mixing in a mixer with an appropriate stirring mechanism or while mixing.
The antifoaming effect of the desired antifoaming agent composition under strong shear or high temperature can be maintained for a longer period of time. When the antifoam composition of the present invention thus obtained is added to a foaming system, it can be prepared by dispersing it in an organic solvent solution or in an organic solvent, or by emulsifying it with an appropriate surfactant. It may also be used as an emulsion type. Examples of such organic solvents include aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, chlorinated hydrocarbon solvents, ether solvents, and alcohol solvents, and examples of surfactants include sorbitan fatty acid esters. Examples include, but are not limited to, glycerin fatty acid ester, propylene glycol fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl ether, ethylene oxide, propylene oxide block copolymer, etc. It's not a thing. In addition, for this emulsion type antifoaming agent, methylcellulose,
Polyvinyl alcohol, sodium alginate, sucrose fatty acid ester, hydroxymethyl cellulose, carboxyethyl cellulose, etc. may be added. The antifoam composition of the present invention may be added to the foaming system as it is, but depending on the purpose and use, fine powder carriers such as methyl cellulose, polyvinyl alcohol, lactose, dextrin, hydrophilic fine powder silica, starch, etc. It may be used as a powder antifoaming agent by adding it together with the above-mentioned surfactant, or it may be used after being solidified by mixing with a solid surfactant and a water-soluble wax. [Example] Next, an example of the present invention will be given. The viscosity in the example shows the measured value at 25°C, and the defoaming durability test result shows the result by the following method. be. (Defoaming durability test) Weigh out 100g of 0.2% sodium oleate aqueous solution into a graduated cylinder with an internal volume of 1000ml, add caustic soda solution to adjust the pH to 11, and then add a predetermined amount of defoaming to this. The change over time in the amount of foaming was examined when the agent was added and then air was continuously introduced at a rate of 1/min through a glass ball filter. Example 1, Comparative Example 1 Clay 100cs dimethylpolysiloxane/KF96
[Product name manufactured by Shin-Etsu Chemical Co., Ltd.] 200 g and 20 g of hydrophobic fine powder silica obtained by treating the surface nolanol groups of dry fine powder silica Aerosil 300L [Product name manufactured by Nippon Aerosil Co., Ltd.] with hexamethyldisilazane. After adding 0.8 g of ammonium carbonate to the three-necked flask described in No. 1, the mixture was heated at 150°C with stirring.
Oil compound A was prepared by heating for a period of time. Next, for comparison, oil compound B was prepared in the same manner as above except that ammonium carbonate was not added. Example 2 300 L of dry fine powder silica Aerosil in Example 1 was replaced with 20 g of dry fine powder silica Aerosil R-972 [trade name manufactured by Degussa, Germany], in which the surface silanol groups of dry fine powder silica were treated with dimethyldichlorosilane. Other than that, oil compound C was prepared in the same manner as in Example 1. Example 3, Comparative Example 2 Hydrophobic fine powder silica Aerosil surface treated with hexamethyldisilane in Example 1
Instead of 300L, fine powder silica Nipsil SS-30p is made by surface treating fine powder silica Nipsil LP with dimethylpolysiloxane with a viscosity of 50cs to make it hydrophobic.
Oil compound D was prepared in the same manner as in Example 1 except that [trade name manufactured by Nippon Silica Kogyo Co., Ltd.] was used.
I made it. For comparison, oil compound E was prepared in the same manner as above except that ammonium carbonate was not added. Example 4 Oil compound F was prepared in the same manner as in Example 1, except that 1.0 g of ammonium chloride was used instead of 0.8 g of ammonium carbonate in Example 1. Example 5, Comparative Example 3 Dimethylpolysiloxane in Example 1
Instead of KF96, use 200 g of KF-50 [trade name manufactured by Shin-Etsu Chemical Co., Ltd.], a copolymer of dimethylpolysiloxane and diphenylpolysiloxane with a viscosity of 100 cs.
Oil compound G was prepared in the same manner as in Example 1 except for the use of the following ingredients. For comparison, oil compound H was prepared in the same manner as above except that 0.8 g of ammonium carbonate was not added. (Defoaming durability test) 1 The defoaming durability test described above was carried out using 0.5 g of a 10% tetrahydrofuran solution of the oil compounds A to H obtained in Examples 1 to 5 and Comparative Examples 1 to 3 above. As a result, the results shown in Table 1 were obtained, and Examples 1 to 5 all gave superior results compared to Comparative Examples 1 to 3.

[Table] 2 Add 100g of this oil compound A to H to sorbitan monostearate nonionic SP-60R.
[Product name manufactured by NOF Corporation] 20g, polyoxyethylene ethyl ether Nitsukol BC-30TX
[Product name manufactured by Nikko Chemicals Co., Ltd.] 20g, and polypropylene glycol Uniol D-4000
[Product name manufactured by Nippon Oil & Fats Co., Ltd.] After heating and mixing with 20g at 60 to 70℃, 840g of water was added and stirred for 20 minutes with a homomixer to emulsify to make emulsions A to H. When the defoaming continuity test described above was carried out using 3.0 g of the % water diluted solution, the results shown in Table 2 were obtained.

[Table] 3 Add 400 g of a block copolymer of polyoxyalkylene glycol and dimethylpolysiloxane F-244 [trade name manufactured by Shin-Etsu Chemical Co., Ltd.] to 100 g of Cono Oil Compounds A to H, and mix it in a homomixer at room temperature. Stir and mix for 20 minutes to make self-emulsifying antifoaming agents A to H, and add this 10% aqueous dispersion.
The defoaming durability test described above was carried out using 2.0g at 80℃.
The results shown in Table 3 were obtained.

[Table] [Effects of the Invention] The antifoam composition of the present invention is obtained by adding an inorganic ammonium compound to a known antifoaming agent consisting of organopolysiloxane oil and finely powdered silica that has been hydrophobically treated with an organosilicon compound. However, the addition of an inorganic ammonium salt compound strengthens the bond between the organopolysiloxane oil and the hydrophobically treated silica, giving it excellent antifoaming properties even under strong shear or high temperatures. This gives you the advantage of

Claims (1)

[Claims] 1 1 Hydrophobic base oil selected from organopolysiloxane oils 100 parts by weight 2 Fine powder silica hydrophobized with an organosilicon compound 1 to 40 parts by weight 3 Inorganic ammonium salt compound 0.1 to 5 parts by weight An antifoam composition comprising: 2. The method for producing an antifoam composition according to claim 1, characterized in that after or while mixing the above-described components 1, 2, and 3, heat treatment is performed at 60 to 200°C for 1 to 5 hours.