JPS60106507A - Powdery antifoaming agent - Google Patents

Abstract

PURPOSE:To obtain powdery antifoaming agent having superior processability, fluidity, and dispersibility into aqueous system and causing no change with the lapse of time by mixing powdery silica, with organo-polysiloxane or polyalkylene glycol. CONSTITUTION:The powdery lantifoaming agent comprises (1) 35-70wt% powdery silica having >=150m<2>/g specific surface area, >=100mu average particle size, and >=150g/l bulk density and (2) 30-65wt% antifoaming compsn. contg. at least one among (a)-(c) described hereunder: (a): organopolysiloxane compsn. consisting of 80-98pts.wt. organopolysiloxane expressed by the formula ( I ) (wherein R<1> is univalent 1-20C hydrocarbon group; 0<=a<=1; 1.90<=a+b<=2.10), and 20-2pts.wt. fine powdery silica, (b); organopolysiloxane contg. polyether group and expressed by the formula (II) (wherein R<2> is a univalent 1-20C hydrocarbon group; G is a group contg. polyether structure; 0<=m<=0.5; 0.02<=n<=0.5; 1.90<=m+n+p<=2.10), and (c): polyalkylene glycol expressed by the formula (III) (wherein R<3> is H, univalent 1-20C hydrocarbon group or acyl group; R<4> is methyl or ethyl; 0<=s; 1<=t<=100).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a powder antifoaming agent, and particularly to a powdery antifoaming agent that has excellent workability, fluidity and antifoaming properties, has excellent dispersibility in aqueous systems, and does not change over time. It is.

For the purpose of extinguishing various types of foam produced industrially, various antifoaming agents are already known.
Regarding the second, those containing Niorganoboliv-chitin as an effective antifoaming ingredient are widely used.

This silicone antifoaming agent is usually solvent-based.

Although it is used in emulsion form, this liquid antifoaming agent has the disadvantage of being difficult to operate when the object to be treated is a powder product (secondary process), and is itself susceptible to deterioration over time. Because of this drawback, powdered antifoaming agents have been developed in which silicone resin is adsorbed on various powders, and these include l) methyl cellulose as the organopolysiloxane component.

A water-bathable resin such as polyvinyl alcohol is emulsified and dispersed using a water-soluble comb such as acacia gum or tragalant gum, and the resulting emulsion is spray-dried and encapsulated. 2) The organopolysiloxane component is cured by ultraviolet light. 3) Organopolysiloxane components encapsulated with inorganic or organic water-soluble @
Those dispersed or covered during trade are divided into three types (C).

However, in the case of (1), the water-soluble resin or rubber that makes up the outer wall of the capsule swells and collapses due to moisture, and as a result, the antifoaming agent component inside the capsule is released, but the capsule itself Because it has hygroscopic properties, it becomes sticky even with a small amount of moisture, and as a result, the smooth powder form becomes sticky due to changes over time.
There is one drawback: it becomes lumpy), has poor storage stability, and loses fluidity when powdered substances are added at the time of use.
Si in the hinyl group-containing polysiloxane and hydrosilyl bond
It is known that the capsules are encapsulated by cross-linking the poly(I/A)-containing chitin or Mercagite group-containing polysiloxane with ultraviolet irradiation, but the capsules are not easily destroyed by water or heat. ), this does not work effectively with water-based foaming, and there is a problem with defoaming performance. Also this 3)
C: For example, magnesium hydroxide-magnesicum carbonate, magnesium oxide, sodium bicarbonate, lactose-
A method using crystalline α-cellulose, a cellulose derivative, polyvinyl alcohol, gelatin, etc. with a particle size of 20 mμN as a carrier, and adsorbing the carbonate 1 niorganosiloxane component. , a method of microencapsulation using cellulose derivatives,
Methods using solid organopolysiloxane are known, but these generally have the disadvantage of being sticky and unable to contain a large amount of antifoaming agent component. There is a common flaw that they have bad sex.

The present invention relates to a powder antifoaming agent C2' that solves these disadvantages.
tr? /I or more - Average particle diameter is 100μ or more, bulk specific gravity (
35-701r powdered silica with a loose weight method) of 15 (1/11% or more), 2) an antifoaming agent component containing at least one of the following 'a) to C) 30-65 weight ratio-a)
Average composition formula: Monovalent hydrocarbon group with prime number 1 to 20, 0≦a≦1゜1.9≦
An organopolysiloxane composition consisting of 80 to 98 parts by weight of an organopolysiloxane represented by a+b≦2.10) and 20 to 2 parts by weight of finely powdered silica, the average formula 2 has 1 to 20 carbon atoms. is a monovalent hydrocarbon group, G is a polyether structure-containing group, 0 m≦0.5.0.02≦n≦0.5-
A polyether group-containing organopolysiloxane having a composition of 1.90 m + n + p≦2.10.

＼l) R is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms or an acyl group -R is a methyl group or an ethyl group, 0≦
S≦30-1≦t≦100).

To explain this, 1. The present inventors conducted various studies on modification of powdered antifoaming agent.2 - Dispersion of antifoaming agent components - Specific surface area, average particle diameter, bulk specific gravity, etc. Using a large force and force, proceed with the grinding with two antifoaming agent components C, and using an antifoaming agent selected from h) to 0) above,
In addition to obtaining an antifoaming agent containing a large amount of C2 as an antifoaming agent component,
Since the antifoaming agent component is absorbed into the pore structure of this silica, the stickiness on the surface of the powder is eliminated, and since the silica has a high bulk specific gravity, floating diffusion of the powder is prevented, which improves the manufacturing process. The present invention was completed by discovering that the product is easier to handle and, secondly, has better dispersibility in aqueous systems.

It is essential that the glue as the first component constituting the powder antifoaming agent of this @mei has a large specific surface area, average particle diameter, and bulk density. That is, since it is desirable that this silica be able to adsorb as much antifoaming agent component as possible, the specific surface area measured by the BET method 52 is 150 d/1! or more - preferably 170d1
It is preferable that the specific surface area is 11 or more. If the specific surface area is less than this, it is impossible to contain a large amount of the antifoaming agent component, and therefore a sticky feeling occurs when a large amount is added. ,
In addition, regarding this semi-average particle size, general grinding products have a secondary agglomerated particle size of 20 to 100 microns as measured by the light transmission particle size distribution measuring method C2.

With this, it is not possible to contain a large amount of antifoaming agent component.
For example, adding a liquid material weighing 30 to 40 µm will cause stickiness, so this should be 100 µm or more, preferably 15 µm or more.
It is preferable to set it to 0 μ or more.

If the particle size is too large, the particles will be too large and become rough, impairing the fluidity of the powder, so it is preferable that the particle size is in the range of 150 to 400 μm. Sara(
Second, the bulk specific gravity (loose weight method) is 30 to 150 g/l, as is the case with general glue products, but the silica itself is straight, and even those with an antifoaming agent added to it are too light, resulting in significant floating diffusion. This will result in poor workability and handling, so this should be more than 150g/, preferably 2001
It is preferable to set 1/ or more. In addition, this Rika is a dry method.

It may be made by any wet method (this is a hemispherical secondary particle in which primary particles with the above-mentioned properties aggregate and the agglomerated space forms a porous pore structure). Although it is considered optimal to use secondary aggregates, this type of silica has the advantage of having excellent hygroscopic properties and having little change over time.

On the other hand, the antifoaming agent component as the second component constituting the powdered antifoaming agent of the present invention, which is added to the powdered antifoaming agent of the present invention, is the above-mentioned a).
The organoborilychitin composition as component a) has the average compositional formula Ra(○H
3) It consists of an organopolysiloxane represented by bSiO4-ab and finely powdered silica, and R1 in the above formula has a hamethyl group, -ethyl group, globyl group-butyl group, hexyl group-decyl group unsubstituted or substituted monovalent carbonized carbon atoms having 1 to 20 carbon atoms of the same or different types selected from alkyl groups such as , octadecyl groups, alkenyl groups such as vinyl groups and allyl groups, and aryl groups such as phenyl groups and styryl groups. is a hydrogen group, a satisfies 0≦a≦1, and 1.
90≦a+b≦2. It is assumed that IO is satisfied. Furthermore, this organopolysiloxane may be either linear or branched or resin-like, and ranges from a liquid with a viscosity of 1ifX several tens of centistokes to a raw rubber-like one with a viscosity of several million centistokes. However, regarding the above a value, the smaller the a, the stronger the antifoaming performance is.<-The larger the a, the greater the affinity with organic substances, and the repellency phenomenon, which is a drawback of conventional silicones, can be avoided. Since 5C2 indicates one-paint tuple property, it is preferable to set this in the range of O≦a≦0.7. The finely powdered silica blended into this organosilochitin may be the one used in conventionally known antifoaming agents, and there are no special restrictions on physical properties or shape, so it can be used with either wet or dry methods. It may be made by the above method, or the surface thereof may be treated with a-type v-lan, alkoxysilane, V-lasan, aminosilane, etc.

This organopolysilochitin resin composition @ is made by mixing the above-mentioned organopolysilochitin and fine powder powder, but for the purpose of improving the antifoaming effect, it is recommended that the two be combined to some extent. Accordingly, a method may be adopted in which a binder is added or a catalyst is added to cause the organopolysiloxane to react with the lanol groups on the surface of the resin.

Component b) as the antifoaming agent component is a riether-modified silicone with an average compositional formula, R2 is a group selected from those exemplified above for R1, and G is ethylene oxide, globylene oxide, butylene oxide F, etc. mtX, a polyether structure-containing group having a polyoxyalkylene glycol structure obtained by polymerization of
O≦m≦0.5. n is a number in the range of 0.02≦n≦0.5, and p is a number that satisfies 1.90≦m + n + p≦2.10, but this silicone compound @ is a polyoxyalkylene Condensation reaction between the hydroxyl group or alkoxy group of glycols and the hydroxyl group or alkoxy group of organosiloxa ν, or the condensation reaction between the hydroxyl group or alkoxy group of glycols and the unsaturated group such as a vinyl group or styryl group introduced in advance right at the end of Glyfur and organosiloxitin. Addition reaction with a human ai/lyl group or mercapto group, and ring-opening addition reaction between an epoxy group introduced in advance on the nigericol side and an amino group or mercapto group of organosilochitin are known. This polyether-modified silicone can be easily obtained by the method (2).In addition, this polyether-modified silicone exhibits bindable property when the m value becomes large, similar to the a value in component I described above, but if it is too large, Antifoaming properties decrease,
If this n value is too small, the antifoaming agent will have poor dispersibility in aqueous systems, and if it is too large, it will become water-soluble and the antifoaming properties will decrease, so these should be 0≦n≦0.3.0≦ n≦0.3
It is preferable to set it as the range of.

In addition, component 0) as the antifoaming agent component is a polyalkylene glycol represented by the general formula R4RO-+0H20H, Otecaca, Otecaca, Otsumu R3.

R is selected from a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or an acyl group; B is a methyl group or an ethyl group; ≦t≦100, p is 1.90≦s + t 10p
The number satisfies ≦2.10, but if the S value, which indicates the degree of polymerization of ethylene oxide, is too small, it will not be sufficiently dispersed in the aqueous system, and if it is too large, it will cause water fm. This is preferably 0≦S≦10.
If the upper value indicating the degree of concentration of propylene oxide or GX butylene oxide is too small, the defoaming performance will be poor, and if it is too large, the diffusibility will be poor.
Since the defoaming performance also tends to decrease, this is
A range of 80 is preferable.

The powder antifoam bottle of the present invention is composed of the above-mentioned powdered silica and antifoam component, but if the blending ratio of these components is too small, the antifoam properties will be insufficient. If the amount is too large, a sticky feeling will result, so it is necessary to adjust the antifoaming component to 65 to 35% by weight of powdered silica and 85 to 65% by weight of powdered silica.

This preferably includes powdered silica from 4 to 65 antifoam components and 60
It is preferable to set it to 35 weight i1%.

The antifoaming agent component may be any one of the above a) to 0), but if the silicone resin component of component a), which is extremely hydrophobic, is used as the main antifoaming component, If used alone, the dispersibility will be poor, so this is recommended)
In addition, it is desirable to use the &XO) components in combination, and the mixing ratio of these components may be the same as that of the foaming system. In addition, there are various combination methods for the combination of components a) to C), for example, a) + b, etc., depending on the type of foaming system. a)+
o).

They may be used in appropriate combinations such as a) + b) + o) - b) + c). The mixing ratio of these additions may be set as desired depending on the type of foaming system and the situation.

The powdered antifoaming agent of the present invention can be easily prepared by combining the powdered silica described above and one or more of the liquid antifoaming agents described above in a container (two containers) and stirring and mixing. However, the desired powder antifoaming agent can be obtained using methanol.

:T. , 9/=ILt. Adding solvents such as alcohols such as isoglopanol, ketones such as acetone, and chlorinated solvents such as methylene chloride also improves the dispersibility of this antifoaming agent in foaming systems. Nonionic, anionic, or cationic surfactants may be added for the purpose of oxidation, and surfactants such as esorbitan fatty acid esters, glycerin fatty acid esters, etc. can be used in particular. If a surfactant with a low HLB is used, it can be expected that dispersibility and co-defoaming properties will be improved.

Next, 52 Examples of the present invention will be given. In one example, parts are parts by weight, % is weight %, and viscosity is a value measured at 25°C. Example 1.

Polyether-modified silicone represented by the following H3-5i-OH3 OH3 was added to 100 g of powdered silica of the seven types shown in Table 1 with different specific surface areas, average particle diameters, and bulk specific gravity, and a chemical compound was obtained. The point at which the powder loses its fluidity is determined. m
The results shown for 1% were obtained, and the specific surface area. It was confirmed that particles with large average particle diameter and bulk specific gravity can contain a large amount of antifoaming agent component.

Example 2゜ 50 parts of various antifoaming agent components were added to 50 parts of powdered silica of sample AI used in Example 1, and the following powdered antifoaming agent samples A to 4 were prepared by forcibly stirring them. did.

Sample A...500c8 dimethylpolysiloxane 94
Sample B: Added polyether-modified silicone B represented by the following formula Sample 0: Added polyether-modified silicone O represented by the following formula OH3-8i -OH3 ■ OR1 Sample D...Add polyalkylene glycoTR D shown by the following formula HO (-OH20H, O-)vfOHOHgO+-HO
H3 Sample E: Added 50% silicone resin A and polyether Sample F: Added a mixture of 50% silicone resin A and polyether silicone 050 Sample G: Added 50% silicone resin A, modified with polyether Added a mixture of Silicone B30'J and Polyal 1 Kylene Glycol D2096 Sample H: Added a mixture of 50% silicone resin A and 50% polyalkylene glycol E represented by the linear formula c, 1h23-c-o4ca-OH ,-09 "-←0H
2-OH2-0-+E-H Sample preparation: Added a mixture of polyether modified silicone B50j and polyalkylene glycol D50%, then 21. Pour 100 g of a 0.02% aqueous solution of polyoxyethylene nonylphenyl ether (HLB13) (foaming solution X) or a 7% polyvinyl alcohol water bath solution (foaming solution Y) into a 1 m measuring cylinder.
To the foaming liquid

Vent nitrogen through a glass pole filter.

When the changes in the amount of aging were measured and their defoaming performance was compared, the results shown in Table 2 above were obtained, and the following was confirmed from the results.

1) Since silicone resin alone has water repellency, good antifoaming properties cannot be obtained.

2-Silicone Resin When 2-nibolyether-modified silicone is used in combination, the dispersibility becomes good and the antifoaming property is also good.

When a polyalkylene glycol is used in combination with a mixture of silicone resin and polyether modified oil, antifoaming properties and antifoaming durability are improved.

Claims (1)

[Claims] 1;1) Specific surface mCBET method) -11150 m'/#
Powdered silica with an average particle diameter of 100 μ or more and a bulk specific gravity (loose weight method) of 15 (1/A or more) 35
~70M11%. 2) Antifoaming agent component containing at least one of the following a) to 0) Weight: 30 to 65. a) In the average composition formula - (2B is a monovalent hydrocarbon group having 1 to 20 carbon atoms, 0≦
Organopolysiloxane composition consisting of 780 to 98 parts by weight of an organopolysiloxane represented by a≦1.1.90≦a + b≦2.10) and 20 to 21 parts by weight of finely powdered silica b) Average composition In the formula, \, 2n2 is a monovalent hydrocarbon group having 1 to 2 carbon atoms, and G is a polyether structure-containing group. 0≦m≦0.5, 0.02≦n≦0.5゜1.90≦m
10n+p≦2.10) Organopolysiloxane C) General formula % Formula % 2(1) Monovalent hydrocarbon group or acyl group. RG ethyl group or ethyl group, 0≦8≦30, 1≦t
A powder antifoaming agent characterized by comprising a polyalkylene glyfur represented by ≦100). .