JPH03104A - Deforming agent composition - Google Patents

Abstract

PURPOSE:To obtain a defoaming agent compsn. separating no component even after the lapse of time and having stability over a long period of time by using polymethylsilsesquioxane having a great affinity for hydrophobic oil as a filler. CONSTITUTION:100 pts.wt. hydrophobic oil consisting of organopolysiloxane oil such as dimethylpolysiloxane oil and/or hydrocarbon oil such as aliphatic hydrocarbon oil is uniformly mixed with 5-100 pts.wt. polymethylsilsesquioxane powder of 0.1-20mum average particle size to obtain a defoaming agent compsn. Since the polymethylsilsesquioxane having a great affinity for the hydrophobic oil is used, satisfactory aging stability is ensured and the sticking of oil spots and silicone is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an antifoam composition, and particularly to an antifoam composition with excellent dispersion stability.

(Prior art) Conventionally, hydrophobic oils such as organopolysiloxane oils and hydrocarbon oils are the main ingredients, and inorganic fillers such as finely powdered silica or (CH3)3Si+/ units and Si
Antifoam compositions containing a filler consisting of a copolymer consisting of ng units and a filler consisting of finely powdered silica are known (for example, Japanese Patent Publications No. 37-14491, No. 43-7691, No. 45).
-13945, 45-23613, 46-14
330, No. 47-1602, No. 47-13487, No. 51-35556, etc.).

However, antifoaming agents that contain finely powdered silica in hydrophobic oils such as organopolysiloxanes and hydrocarbon oils have poor dispersion stability due to the poor affinity between hydrophobic oils and silica.
The drawback is that silica settles over time or aggregates in the foaming system, causing oil spots and stains due to silicone adhesion.

Also, for hydrophobic oils such as organopolysiloxane oils and hydrocarbon oils (CHs)! S 1+z□ unit and Sto
Antifoaming agents blended with copolymers consisting of , and units have good dispersion stability, but have the disadvantage that their antifoaming effects are significantly inferior to those blended with fine silica powder, so they must be used in combination with fine silica powder. It was difficult to exhibit a sufficient antifoaming effect.

As a result of intensive studies to solve these drawbacks, the inventors found that
When the main component is organopolysiloxane oil and/or hydrocarbon oil and polymethylsilsesquioxane powder with an average particle size of 0.1 to 20 μm is blended with this hydrophobic oil as a filler, the resulting The dispersion stability of the foaming agent composition is extremely good, and the components do not separate over time, and the foaming system does not cause aggregation or stains due to oil spots or silicone adhesion. This discovery led to the present invention.

(Problems to be Solved by the Invention) Therefore, the first object of the present invention is to provide an antifoam composition that does not separate its components over time and is stable over a long period of time.

A second object of the present invention is to provide an antifoaming composition that does not cause aggregation in a foaming system and cause oil spots or stains due to silicone adhesion.

(Means for Solving the Problems) That is, the present invention consists of: (1) 100 parts by weight of a hydrophobic oil consisting of an organopolysiloxane oil and/or a hydrocarbon oil; Sun powder: This is an antifoam composition characterized by consisting of a mixture of 5 to 100 parts by weight uniformly mixed together.

The hydrophobic base oil as the first component constituting the composition of the present invention is selected from organopolysiloxane oils or hydrocarbon oils. This organopolysiloxane oil is represented by the general formula %. In the formula, %R" is an alkyl group such as a methyl group, ethyl group, propyl group, butyl group; an aryl group such as a vinyl group or tolyl group; a part or all of the hydrogen atoms bonded to the hydrocarbon of these groups is a halogen Unsubstituted or substituted monovalent carbon atoms having 1 to 20 carbon atoms of the same or different type, such as chloromethyl group substituted with atom, cyano group, etc., 3゜3.3-)lifluoropropyl group, cyanopropyl group, etc. It is selected from hydrogen groups, and the average value of a is suitably from 1.9 to 2.1.

Such organopolysiloxane oils include dimethylpolysiloxane, diethylpolysiloxane, methylphenylpolysiloxane, polydimethyl-polydiphenylsiloxane copolymer, polymethyl-3,3,3-)lifluoropropylsiloxane, polydimethyl-chloropropyl Examples include methylsiloxane, but dimethylpolysiloxane oil is particularly preferred from the viewpoint of antifoaming properties and economic efficiency.The terminals of the organopolysiloxane are usually capped with trimethylsilyl groups, but the terminals are capped with hydroxyl groups. Good too.

On the other hand, hydrocarbon oils include aliphatic hydrocarbon oils, alicyclic hydrocarbon oils, aromatic hydrocarbon oils, etc., especially 7
Aliphatic compounds having a boiling point of 0° C. or higher are preferred, and specific examples thereof include heptane, octane, nonane, decane, dodecane, tetradecane, hexadecane, and the like.

Note that these base oils may be liquid at room temperature, but from the viewpoint of antifoaming properties and workability, they should have a viscosity of 20 to 25°C at 25°C.
It is preferably of 1,000,0OOcS,
Particularly preferred is a range of 50 to 10.0 OOcS.

The second component polymethylsilsesquioxane powder in the composition of the present invention is used as a filler,
By blending this, antifoaming properties can be imparted to the composition. This powder has a lower specific gravity than conventional inorganic fillers such as fine silica powder, and has good affinity with hydrophobic oils, so even if it is filled in a large amount, the specific gravity of the composition will not increase too much, and the viscosity will not increase. Because of their small size, the compositions of the present invention are swable, fluid, and easy to use.

Further, it is preferable that this powder has an independent spherical shape, and that the proportion of particles having a particle size distribution within ±30% of the average particle size is 80% by weight or more.

The above-mentioned polymethylsilsesquioxane powder used in the present invention is used for boat fishing by hydrolyzing and condensing methylalkoxysilane or its partially hydrolyzed product in an aqueous solution containing an alkaline substance, dehydrated and dried, and then taken out. However, it is preferable that methyltrialkoxysilane is hydrolyzed and condensed in an aqueous solution containing an alkaline earth metal hydroxide or an alkali metal carbonate. Method (Tokuko Sho 56-3
No. 9808), in an aqueous solution of ammonia or amines,
Method for hydrolyzing and condensing methyltrialkoxysilane and/or its partial hydrolysis tank hardware (JP-A-60-1
No. 3813, No. 63-77940) and other known methods.

The particle size of polymethylsilsesquioxane powder is 0°1~2
0tIm, preferably 0.5-6 μm.

If it is less than 0.1 μm, it is difficult to produce spherical fine particles, it is not easy to handle, and it is difficult to disperse uniformly, and if it exceeds 20 μm, sufficient antifoaming properties cannot be imparted.

The amount of the second component in the composition of the present invention is not particularly limited, but 5 parts by weight per 100 parts by weight of the first component.
-100 parts by weight is preferred, particularly 10-60 parts by weight.
It is preferable that the amount is less than 5 parts by weight, and if the amount is less than 5 parts by weight, a sufficient antifoaming effect will not be obtained and oil spots will likely occur. On the other hand, if the blending amount exceeds 100 parts by weight, the viscosity of the composition increases, resulting in poor workability and deterioration in antifoaming properties.

In the present invention, an antifoam composition having excellent dispersion stability can be obtained by including the first and second components as essential components. By incorporating finely powdered silica as a component, it is possible to further impart rapid-acting foam-breaking and defoaming effects.

The fine powder silica as the third component may be either dry silica or wet silica, which has been conventionally known as a silica filler. Examples of such fine powder silica include precipitated silica, silica xerogel, hiemed silica, and these. Examples include treated silica whose surface is treated with organic silyl groups, specifically Aerosil (trade name, manufactured by Nippon Aerosil Co., Ltd.) and Nibusil (trade name, manufactured by Nippon Silica Co., Ltd.).
, Thyroid (trade name, manufactured by Fuji Divilin Co., Ltd.), Cabosil (trade name, manufactured by Cabot, USA), Santocel (trade name, manufactured by Monsando Chemical Company, USA), and the like. The finely powdered silica preferably has a specific surface area of 50 n(/g or more) as determined by the BET method, and the blending amount is 1 to 100 parts by weight of the hydrophobic oil as the first component.
The amount is 20 parts by weight, preferably 3 to 15 parts by weight. If it is less than 1 part by weight, its performance will not be fully exhibited, and if it is more than 20 parts by weight, the viscosity of the composition will increase, resulting in poor workability, making it difficult to handle, and also worsening the dispersion stability of the composition. .

The antifoam composition of the present invention can be easily obtained by mixing the above-mentioned first and second components and a predetermined amount of the third component added as necessary in a mixer equipped with an appropriate stirring mechanism. However, when it is added to a foaming system, it may be used as an emulsion by dispersing it in an organic solvent and emulsifying it with a suitable surfactant.

Examples of such organic solvents include aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, chlorinated hydrocarbon solvents, ether solvents, and alcohol solvents.

Examples of surfactants include sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl ether, and block copolymers of ethylene oxide and propylene oxide. However, it is not limited to these.

When used as an emulsion-type antifoaming agent, protective colloid agents, thickeners, stability improvers, etc. during emulsification include carboxymethyl cellulose, polyvinyl alcohol, sodium alginate, sig sugar fatty acid ester, hydroxymethyl cellulose, carboxyethyl cellulose, etc. may be added.

The antifoaming agent 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. may be added to the foaming system. It may be used as a powder antifoaming agent by adding it together with a surfactant, or it may be solidified by mixing with a solid surfactant, water-soluble wax, etc. and used.

(Effects of the Invention) The antifoaming composition of the present invention uses polymethylsilsesquioxane, which has good affinity for hydrophobic oils, as a filler, so it not only has good stability over time, but also prevents oil spots and silicone. Since adhesion can be prevented, no stains occur during use.

In particular, when finely powdered silica is blended as the third component, the composition of the present invention becomes even more useful because it can provide immediate foam-breaking and defoaming effects.

(Examples) The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited thereto.

Example 1゜ It was synthesized by the method.

In a 60 f stainless steel container equipped with a stirrer, thermometer, dropping funnel, and cooling jacket, water and potassium hydroxide were charged to give an aqueous potassium hydroxide solution with the concentration shown in Table 1, and the mixture was cooled to 15°C. .

Next, a predetermined amount of methyltrimethoxysilane was added dropwise over 2 hours with stirring, while the temperature and stirring rotation speed were kept constant.

After the dropwise addition was completed, stirring was continued for an additional hour, and then acetic acid was added to neutralize the mixture. The resulting suspension was filtered, and dehydrated and washed twice using a centrifuge to form a cake. This was dried in a dryer at 150'C until the moisture content was 20% or less, and then crushed in a jet mill to obtain powdered polymethylsilsesquioxanes P-1 to P-1 with excellent free-flowing properties. -4 was obtained.

Dimethylpolysiloxane KF-96 [manufactured by Shin-Etsu Chemical Co., Ltd.], in which both ends of polymethylsilsesquioxane are blocked with trimethylsilyl groups, is used as the hydrophobic oil shown below.
Polymethylsilsesquioxane powders P-1 and P-, which were previously synthesized as fine powder fillers while using [trade name]
No. 2 was used in the proportion shown in Table 2, and the filler was uniformly incorporated into the base silicone oil by stirring at 150 DEG C. for 3 hours to obtain antifoam compositions A-D.

In addition, as a comparison sample, instead of polymethylsilsesquioxane, fine powdered silica Aerosil (trade name manufactured by Nippon Aerosil ■) or Nibusil (manufactured by Nippon Silkani Industry ■) was used.
Defoamer composition E-C using [trade name] and CH3S i O+/ instead of polymethylsilsesquioxane.
z unit and Sin.

silicone resin with a molar ratio of 0.75 to the unit (50
% xylene solution) to obtain antifoam composition H.

Regarding the properties of these antifoam compositions, viscosity, dispersion stability, and workability were investigated. Furthermore, each antifoam composition was made into a 10% tetrahydrofuran solution, and 1.0 g of this solution was added to defoam. When a sex test was conducted, the results shown in Table 2 were obtained.

The characteristics and antifoaming properties of the antifoam composition were measured or evaluated by the following methods.

Viscosity Measured at 25°C using an iBM rotational viscometer.

Dispersion stability: The antifoam composition was placed in a glass bottle and allowed to stand, and one week later, the appearance was observed to determine whether the filler had separated and settled.

Antifoaming agent test: 100 g of sodium oleate aqueous solution with a concentration of 0.2% in a graduated cylinder with an internal volume of 1,000 m1
was weighed out, a predetermined amount of antifoaming agent was added thereto, and then air was continuously blown through a glass pole filter at a rate of iN/min. Changes in the amount of foaming over time were measured.

From the results in Table 2, it can be seen that the composition of the present invention is satisfactory in both its various properties and antifoaming properties, whereas the composition of the comparative sample is satisfactory in its various properties. It has been demonstrated that it is not possible to achieve both antifoaming and antifoaming properties.

Example 2゜To 1100 g of the antifoam composition A-) prepared in Example 1, 40 g of sorbitan monostearate Rheodol 5S-10 (product name manufactured by Kao ■) and polyoxyethylene sorbitan monostearate Rheodol To-120 were added. (Kao ■
[Product Name] 40g was prepared, stirred and mixed at 70-80°C for 15 minutes, and then 820g of water at 20°C was gradually added over 20 minutes while stirring with a homomixer to emulsify it and make an emulsion type. Antifoaming agent (emulsion A
~H) was obtained. This emulsion was diluted with 10% water, 5.0 g of this diluted solution was added, and a defoaming test was carried out.
Furthermore, the diluted solution was placed in a glass bottle and allowed to stand for 1 week.After one week, the appearance was observed to see if the emulsion had separated and settled, and the dispersion stability was determined.The results are shown in Table 3.

As is clear from the results in Table 3, it was demonstrated that good results could be obtained even when the composition of the present invention was made into an emulsion type.

Example 3゜Dimethylpolysiloxane KF-96 used in Example 1
(1, OOOcs) and 200 g of polymethylsilsesquioxane powder P-3 or P-4 synthesized earlier as a fine powder filler were subjected to the same treatment as in Example 1, and antifoam compositions K and L were prepared. I got it.

The viscosities of these compositions are 1,700 cp and 1,4 cp, respectively.
50 cp, and both dispersion stability and workability were good.

Further, these antifoam compositions K and L were emulsified according to the same recipe as in Example 2 to obtain emulsion type antifoam agents (emulsions K and L). The dispersion stability of emulsions K and L diluted with 10% water was examined in the same manner as in Example 1, and it was confirmed that both emulsions were good.

Example 4 Emulsions A-L obtained in Examples 2 and 3 were subjected to a dilution high temperature stability test and mechanical stability test using the following method, and the results were as shown in Table 4. Obtained.

In addition, each test was conducted by the following method.

High-temperature stability test of diluted solution: Dilute and disperse 1'Og of sample in 90g of water, put it in a 200ml beaker, and incubate at 130°C in a high-temperature sterilizer for 30 minutes.
After heating for 0 minutes, the state was observed when it was left to cool to room temperature, and the state was observed and evaluated after being redispersed by stirring gently with a spatula.

Evaluation criteria ◎: There is no oil floating or dirt on the wall surface, and it is easily redispersed.

○: There is some oil floating and dirt on the wall surface, but it is easily redispersed.

Δ: There is oil floating and dirt on the wall surface, and some parts are not redispersed.

×: There is oil floating and dirt on the wall surface, and there is almost no redispersion.

Mechanical stability test of diluted solution: 20 g of sample was diluted with 180 g of water, placed in a 300 m2 beaker, stirred for 10 minutes at 7°00 rpm using a homomixer, and then the state was observed and evaluated.

Evaluation criteria ◎...There is almost no oil floating or dirt on the wall surface.

○...There is no oil floating, but the wall surface is a little dirty.

Δ...There is some oil floating and the wall surface is also dirty.

×: There is a large amount of oil floating.

As is clear from the results in Table 4, the composition of the present invention was demonstrated to be fully satisfactory in both high temperature stability and mechanical stability.

Claims (1)

[Claims] (1) Hydrophobic oil consisting of organopolysiloxane oil and/or hydrocarbon oil: 100 parts by weight (2) Average particle size 0.1
An antifoaming agent composition comprising a uniform mixture of 5 to 100 parts by weight of spherical polymethylsilsesquioxane powder of ~20 μm.