JP3222049B2 - Self-emulsifying antifoam composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-emulsifying antifoaming composition, and more particularly to a self-emulsifying antifoaming composition suitable as an antifoaming agent for water-based paints and water-based inks.

[0002]

2. Description of the Related Art Silicone antifoaming agents mainly composed of an oil compound composed of dimethylpolysiloxane and finely divided silica have various excellent properties as compared with other types of antifoaming agents. It is widely used in manufacturing processes involving foaming in industries such as the oil, fats, fermentation, rubber, food, petrochemical, textile, pulp and paper, and pharmaceutical industries. Due to its hydrophobic nature, this antifoaming agent is widely used as an emulsion type antifoaming agent obtained by dispersing the above-mentioned oil compound together with a surfactant in water.

However, this emulsion-type antifoaming agent cannot provide a desired defoaming effect because the emulsion is destroyed when the liquid to be treated is at a high temperature or is subjected to a high shearing force. May be promoted, and during long-term storage, the emulsion separates, resulting in latex,
In water-based paints, water-based inks, dyeing industries, and the like, the water repellency of the separated dimethylpolysiloxane has the disadvantage of causing repelling or uneven dyeing on the object.

Therefore, it has been proposed to use a so-called polyether-modified siloxane in which a polyoxyalkylene group has been introduced into the siloxane (see US Pat. No. 3,233,986). A water-soluble defoaming agent comprising a copolymer / nonionic surfactant has been proposed as an effective one for high-temperature dyeing (see Japanese Patent Publication No. 58-34167). Is added to prevent the occurrence of repelling, but this has a disadvantage that the defoaming property at low temperatures is particularly poor.

[0005]

Therefore, there has been proposed a self-emulsifying type defoaming agent in which an oil compound comprising dimethylpolysiloxane and finely divided silica is used in combination with the above polyether-modified siloxane (Japanese Patent Publication No. 52-19836, JP-B-52-22638, JP-B-54-43015, JP-B-55-23084,
JP, 55-161850, A), dyeing, water-based, paint,
Used for applications such as aqueous inks and various oils. However, although these products have good defoaming properties, repelling and uneven dyeing occur when the added amount is large for application to a high foaming system, and when added to a water-based paint or water-based ink, the gloss of the coating film is impaired. Problem occurs.

The antifoaming agent is an antifoaming agent having improved paintability by introducing an alkyl group other than a methyl group into a base oil of an oil compound or a polyether-modified siloxane (Japanese Patent Publication No. 61-34847, JP-A-61-34847; Showa 54
-149388, JP-A-60-172315), an antifoaming agent composed of polyether-modified siloxane / fine-powder silica / polypropylene glycol (see JP-B-54-9145), an alkyl-polyether co-modified siloxane / Antifoaming agents composed of finely divided silica have also been proposed (see JP-A-57-180407), which have relatively good antifoaming properties and provide an antifoaming agent which does not easily cause cissing. ,
The water-based paints and water-based inks using these are not necessarily satisfactory in the gloss of the coating film, and are required to have further improved properties.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a self-emulsifying defoamer composition which solves such disadvantages and problems of the prior art, and comprises (1) an average composition formula G _a R _b SiO _{(4-ab) / 2} [wherein G is a general formula -R'-O- (CH ₂ CH ₂ O) _m- [CH ₂ CH (CH ₃ ) O] _n-
R "(where R 'is a divalent hydrocarbon group having 1 to 10 carbon atoms, R" is a monovalent organic group selected from an alkyl group having 1 to 6 carbon atoms, an acetyl group and an isocyanic acid group, or a hydrogen atom , M, n
Is an oxyalkylene group represented by 0 ≦ m ≦ 50, 10 ≦ n ≦ 50 and 0 ≦ m / m + n ≦ 0.5), R is a monovalent hydrocarbon group having 1 to 18 carbon atoms, and a and b are positive numbers of 1.9 <A + b <2.1,
And 0.01 ≦ a / a + b ≦ 0.2], wherein the polyoxyalkylene-modified silicone oil is 50 to 99% by weight,
(2) 0.5 to 40% by weight of hydrophobized silica fine powder, and (3) 0.1 to 20% by weight of a nonionic surfactant.

That is, the present inventors have conducted various studies to develop a self-emulsifying type antifoaming agent which is excellent in defoaming property and does not cause repelling. As a result, the molar ratio of ethyleneoxy groups / propyleneoxy groups was found. When a polyoxyalkylene-modified silicone oil having a high propyleneoxy group content of 0/100 to 50/50 is mixed with a hydrophobic silica fine powder and a nonionic surfactant, an antifoaming composition having excellent properties is obtained. This composition has good water dispersibility and excellent defoaming properties, and it has been found that it does not generate repelling even when used in aqueous paints and inks. The present invention was completed by confirming that a glossy coating film could be obtained when used in addition to paints and water-based inks.

The present invention provides the above (1), (2) and (3)
The present invention relates to a self-emulsifying antifoaming composition comprising components, which will be described in more detail below. The polyoxyalkylene-modified silicone oil as the component (1) constituting the self-emulsifying type antifoaming composition of the present invention is a main component of the present composition, and has an antifoaming property, a water dispersing property and a repelling resistance. This is to be expressed by the following average composition formula G _a R _b SiO _{(4-ab) / 2} .

Here, G is an oxyalkylene group represented by the general formula -R'-O- (CH ₂ CH ₂ O) _m- [CH ₂ CH (CH ₃ ) O] _n -R " Is a divalent hydrocarbon group having 1 to 10 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexamethylene group, an octamethylene group, a decamethylene group, and R "is a methyl group, an ethyl group propyl group, and a butyl group. , A monovalent organic group selected from an alkyl group having 1 to 6 carbon atoms such as a pentyl group and a hexyl group, an acetyl group, an isocyanic acid group and the like, or a hydrogen atom . If the value is less than 10, the hydrophobicity is too strong and the water dispersibility becomes poor, and cissing tends to occur, and if it exceeds 100, the hydrophilicity becomes too strong and the defoaming property is insufficient, and the viscosity at the time of dilution is reduced. The workability is deteriorated due to the increase, and when m> n, the hydrophilicity is strong even in this case. Water-based paint too with the decrease of anti-foaming properties,
When used as an aqueous ink, the gloss of the coating film becomes inferior, so that m and n are 0 ≦ m ≦ 50, 10 ≦ n ≦ 50 and 0 ≦ m / m + n ≦ 0.5, preferably 0 ≦ m ≦ 30, 10 ≦ n
≦ 30 and 0 ≦ m / m + n ≦ 0.35.

R is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, etc. An alkenyl group such as a vinyl group or an allyl group;
An aryl group such as a phenyl group or a tolyl group; a cycloalkyl group such as a cyclohexyl group, or a chloromethyl group in which some or all of the hydrogen atoms bonded to carbon atoms of these groups have been substituted with halogen atoms, cyano groups, or the like; An unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms selected from a 3-chloropropyl group, a 3,3,3-trifluoropropyl group, a cyanoethyl group and the like. It is preferable that 90 mol% or more of the groups is a methyl group. Note that a and b are positive numbers, respectively.
1.9 <a + b <2.1, but if the value of a / a + b is less than 0.01, the hydrophobicity is too strong and the water dispersibility is poor, and cissing is likely to occur. Since the properties are too strong and the defoaming properties are insufficient, this should be set to 0.01 ≦ a / a + b ≦ 0.2, preferably 0.1.
It is preferable that 02 ≦ a / a + b ≦ 0.1.

The polyoxyalkylene-modified silicone oil is preferably in a liquid state at room temperature.
When the viscosity at 10 cSt is lower than 10 cSt, the obtained self-emulsifying defoamer composition is easily separated and has low stability.
If it is higher than 00,000 cSt, the obtained self-emulsifying type antifoaming composition becomes difficult to separate when it is diluted with water, and the workability is deteriorated. cSt. As the polyoxyalkylene-modified silicone oil, those commercially available as polyether-modified silicone may be used, or a method known in the art, for example, a method in which an organopolysiloxane containing a ≡SiH group is added to a vinyl group or an allyl group at a molecular chain terminal. A polyoxyalkylene compound having an unsaturated group such as a group can be easily obtained by an addition reaction in the presence of a platinum catalyst. If the compounding amount of the component (1) in the composition of the present invention is less than 50% by weight, the viscosity increases and the workability deteriorates, and the water dispersibility decreases. This will be less
It is required to be 50 to 99% by weight, but a more preferable range is 70 to 95% by weight.

Next, the finely divided silica as the component (2) constituting the self-emulsifying type antifoaming composition of the present invention is required to have been subjected to a hydrophobic treatment. Any of known dry silica and wet silica may be used. Examples thereof include Aerosil [trade name, manufactured by Nippon Aerosil Co., Ltd.], Nip Seal [trade name, manufactured by Nippon Silica Industry Co., Ltd.], Thylsia [Fuji Silysia Co., Ltd.] Brand name), Cabosil [trade name of Cabot Corporation in the United States], Santocell [trade name of Monsanto Chemical Company in the United States], etc., which have a specific surface area of 50 m ² / g or more according to the BET method. Is preferred.

The hydrophobizing treatment of the finely divided silica may be carried out by a conventionally known method. Therefore, the finely divided silica may be treated with an organosilicon compound. Silazane, trimethylethoxysilane, trimethylsilane, trimethylchlorosilane, dimethyldichlorosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldiethoxysilane, vinylmethyldimethoxysilane, methyltriethoxysilane, trimethylsilylmercaptan,
Vinyldimethylacetoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane,
Examples thereof include 1,3-diphenyltetramethyldisilazane, trimethylsilylisopropylamine, trimethylsilylethylamine, phenyldimethylsilylpropylamine, and vinyldimethylsilylbutylamine.

The hydrophobization treatment with this organosilicon compound is carried out by using a nitrogen-containing organosilicon compound or a chlorine-containing organosilicon compound as disclosed in JP-B-51-35556 and JP-B-52-31836. Silanol groups on the silica surface are preferably subjected to hydrophobizing treatment. In particular, those having silanol groups on the surface thereof subjected to hydrophobizing treatment with hexamethyldisilazane, 1,3-diphenyltetramethylsilazane, trimethylchlorosilane, dimethyldichlorosilane, etc. Although preferred from the viewpoint of defoaming performance, the method of reacting the organosilicon compound with the finely divided silica may be carried out by the methods described in the known JP-B-47-30422 and JP-B-53-44504. When the amount of the hydrophobized silica fine powder is less than 0.5% by weight in the composition of the present invention, the defoaming performance becomes inferior. When the amount is more than 40% by weight, the viscosity of the composition increases and the water dispersion becomes poor. This is because
It is required to be in the range of 0.5 to 40% by weight, but preferably in the range of 2 to 20% by weight.

Next, the nonionic surfactant as the component (3) constituting the self-emulsifying type antifoaming composition of the present invention comprises:
The antifoaming composition of the present invention is used for the purpose of improving the dispersibility in water without deteriorating the defoaming property, and includes a conventionally known nonionic containing an alkylene oxide bond in the molecule. Anionic surfactants can be used. Specific examples thereof include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, and polyoxyethylene castor oil derivative. .

However, the nonionic surfactant used in the present invention is inferior in water dispersibility since the nonionic surfactant becomes lipophilic when the added mole number of the alkylene oxide is less than 5 mol. When it exceeds 25 mol, the defoaming property is adversely affected, and it becomes solid and difficult to handle, so it is preferable to be in the range of 5 to 25 mol, preferably in the range of 6 to 20 mol. Good. If the amount of the component (3) in the composition of the present invention is less than 0.1% by weight, the water dispersibility decreases, and if it is more than 20% by weight, the defoaming property deteriorates. It is necessary to have a range of, but the preferred range is 1 to 10
% By weight.

The self-emulsifying defoamer composition of the present invention can be obtained by mixing predetermined amounts of the above-mentioned components (1), (2) and (3) in a mixer having an appropriate stirring mechanism. These components can be mixed uniformly using, for example, a mixer such as a homomixer. The mixing method is not particularly limited, and the components may be mixed by heating in a range of 40 to 130 ° C.
In the self-emulsifying antifoaming composition of the present invention thus obtained, the (1) component polyoxyalkylene-modified silicone oil has a molar ratio of ethyleneoxy groups / propyleneoxy groups of 0/100 to 50/50. / 50, which has a high content of propyleneoxy groups, so that this composition has a good balance between hydrophobicity and hydrophilicity, and therefore has excellent water dispersibility and defoaming properties. When it is used by adding it to water-based inks, latexes, and the like, repellency does not occur, and an advantage is obtained in that a coating film having excellent gloss can be obtained.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples and comparative examples.

[0020]

EXAMPLES Examples of the present invention and comparative examples will now be described.
The viscosities in the examples show the measured values at 25 ° C., and the various physical property values in the examples show the measurement results by the following methods. (Water dispersibility test) In a 500 ml glass beaker, 20 g of the self-emulsifying defoamer composition and 380 g of deionized water were put, and the diameter was 8 cm.
The dispersion after stirring at 400 rpm for 3 minutes with a glass stirring blade was visually observed and evaluated according to the following criteria. 〇: easily dispersed to form a uniform emulsion. Δ: Dispersed, but precipitates or oil floating. ×: Not dispersed. (Defoaming test for nonionic foaming liquid) Emulgen 909, a polyoxyethylene nonylphenyl ether (trade name, manufactured by Kao Corporation), was placed in a 1-liter measuring cylinder.
100 g of a 0.1% aqueous solution of
500 ppm was added, and the foaming amount after 20 minutes [total ml amount of (foam volume + liquid volume)] was measured by an air bubbling method in which air was blown at a rate of 1 liter / minute through a glass diffuser stone at room temperature. .

(Repelling, gloss test) After adding 1% by weight of a self-emulsifying defoamer composition to emulsion Boncoat EC-846 for gloss paint (trade name, manufactured by Dainippon Ink and Chemicals, Incorporated), it was applied to an iron plate. The surface state after brush coating and drying was visually observed and evaluated as follows. Repelling Δ: Same as blank (without adding antifoaming agent), Δ: Some repelling is present, ×: Repelling is innumerable. Gloss Δ: Same as blank (no antifoaming agent added), Δ: Some clouding is observed, ×: No gloss at all.

Examples 1 to 6 and Comparative Examples 1 to 7 The following five types (1) -1 to (1) -5 were prepared as the polyoxyalkylene-modified silicone oil (1). (1) -1 G ¹ _0.05 (CH ₃ ) _1.98 SiO _0.985 G ¹ = -C ₃ H ₆ O [CH ₂ CH (CH ₃ ) O] ₂₇ H, viscosity 600 cSt, (1) -2 G ² _0.09 (CH ₃ ) _1.97 SiO _0.97 G ² = -C ₃ H ₆ O (CH ₂ CH ₂ O) ₆ [CH ₂ CH (CH ₃ ) O] ₂₄ H, viscosity 500 cSt
, (1) -3G ² _0.65 (CH ₃ ) _1.96 (C ₁₀ H ₂₁ ) _0.03 SiO _0.98 G ² = above, viscosity 1,000 cSt, (1) -4 G ³ _0.13 (CH ₃ ) _1.93 SiO _0.97 G ³ _{= -C 3 H 6 O (CH} 2 CH 2 O) 12 [CH 2 CH (CH 3) O] 4 H, viscosity 400cSt
_{^{, (1) -5 G 4 0.13}} (CH 3) 1.93 SiO 0.97 G 4 = -C 3 H 6 O (CH 2 CH 2 O) 10 H, viscosity 600 cSt.

The following three types (2) -1 to (2) -3 were prepared as the hydrophobized silica fine powder of the component (2). (2) -1 Aerosil 300 [Japan Aerosil Co., Ltd.]
Ltd. trade name, specific surface area 300 meters ² / g] of the hydrophobic silica fine powder treated with hexamethyldisilazane, (2) silica -2 hydrophobic treated powder, Nipsil SS-100L [Nippon Silica Industrial Co., Product name, specific surface area 90 m ² / g], (2) -3 Untreated silica fine powder, Sylysia 310
[Fuji Silysia Corp. product name, specific surface area 300m ² / g]

Further, the following two types (3) -1 and (3) -2 were prepared as the nonionic surfactant of the component (3). (3) -1 polyoxyethylene (EO = 11 mol) nonylphenyl ether; (3) -2 polyoxyethylene (EO = 20 mol) sorbitan monooleate.

Next, the components (1), (2), and (3) were mixed in the amounts shown in Table 1 at 100 ° C. for 3 hours under a nitrogen gas stream to obtain a self-emulsifying defoamer composition. The prepared compositions were tested for water dispersibility, defoaming property, cissing test, and gloss, and the results shown in Table 1 below were obtained.

Comparative Example 8 Polyoxyalkylene-modified silicone oil (1) -2 used in the above-mentioned example (75% by weight), nonionic surfactant (3) -15% by weight and dimethyl silicone having a viscosity of 1,000 cSt 90 parts by weight of oil / KF-96 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and 10 parts by weight of hydrophobized silica fine powder / nip seal SS-100L (described above) are mixed at 150 ° C. for 2 hours under a nitrogen gas stream. 20% by weight of the oil compound obtained by
A self-emulsifying defoamer composition was prepared by stirring at 000 rpm for 10 minutes, and the composition was tested for water dispersibility, defoaming property, cissing test and gloss. The results were as shown in Table 1 below. was gotten.

[0027] Based on JP Comparative Example 9-B 54-9145, polyoxyalkylene-modified silicone oil _{^{(1) -6 G 5 0.15 (}} CH 3) 1.91 SiO 0.97 G 5 = -C 3 H 6 O (CH 2 CH ₂ O) ₂₅ [CH ₂ CH (CH ₃ ) O] ₂₅ C ₄ H ₉ , viscosity 1,6
Polypropylene glycol uniol having an average molecular weight of 1,200 instead of the nonionic surfactant as the component (c), 5% by weight, 5% by weight of hydrophobized silica fine powder (2) -1 (mentioned above), and (3) the component (3) A self-emulsifying defoamer composition was prepared by mixing 85% by weight of D-1200 [trade name of Nippon Yushi Co., Ltd.] at 100 ° C. for 3 hours under a stream of nitrogen gas. When the defoaming property, the cissing test, and the gloss were tested, the results shown in the following Table 1 were obtained.

[0028]

[Table 1]

[0029]

The present invention relates to a self-emulsifying type antifoaming composition. This composition comprises a polyoxyalkylene-modified silicone oil as the component (1) used as an ethyleneoxy group / propyleneoxy group. Is 0.
/ 100 to 50/50, which has a high content of propyleneoxy groups, so that a predetermined amount of the hydrophobized silica fine powder as the component (2) and the nonionic surfactant as the component (3) are added thereto. The mixed composition becomes a self-emulsifying defoaming composition that has a good balance of hydrophobicity and hydrophilicity and is excellent in water dispersibility and defoaming properties. Then, there is an advantage that repelling does not occur and a glossy coating film can be obtained.

Continuation of the front page (72) Inventor Satoshi Kuwata 1-10 Hitomi, Matsuida-machi, Usui-gun, Gunma Prefecture Inside Silicone Electronic Materials Technology Laboratory, Shin-Etsu Chemical Co., Ltd. (56) References JP-A-60-106507 (JP, A JP-A-54-149388 (JP, A) JP-A-56-48211 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01D 19/04

Claims (1)

(57) [Claims] (1) Average composition formula: G _a R _b SiO _{(4-ab) / 2 wherein} G is a general formula: —R′—O— (CH ₂ CH ₂ O) _m — [CH ₂ CH (CH ₃ ) O] _n-
R "(where R 'is a divalent hydrocarbon group having 1 to 10 carbon atoms, R" is a monovalent organic group selected from an alkyl group having 1 to 6 carbon atoms, an acetyl group and an isocyanic acid group, or a hydrogen atom , M, n
Is an oxyalkylene group represented by 0 ≦ m ≦ 50, 10 ≦ n ≦ 50 and 0 ≦ m / m + n ≦ 0.5), R is a monovalent hydrocarbon group having 1 to 18 carbon atoms, and a and b are positive numbers of 1.9 <A + b <2.1,
And 0.01 ≦ a / a + b ≦ 0.2], 50 to 99% by weight of a polyoxyalkylene-modified silicone oil, (2) 0.5 to 40% by weight of hydrophobized silica fine powder, and (3) nonionic surfactant 0.1 A self-emulsifying antifoaming composition, characterized in that the composition comprises from 20 to 20% by weight.