JP2685685B2 - Foam suppressor 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 suds suppressor composition, and more particularly to a suds suppressor composition exhibiting excellent dispersion stability and foam suppressing property when added to an aqueous cutting oil, an oil agent for dyeing process and the like. It is a thing.

[0002]

2. Description of the Related Art Silicone defoaming agents containing dimethylpolysiloxane as a main component have various excellent properties as compared with other defoaming agents, so that they can be used in general chemical industries involving foaming. Widely used in the process. However, since this dimethylpolysiloxane is essentially hydrophobic, it is used as an emulsion type defoaming agent in which it is dispersed in water using a surfactant. When the liquid to be treated is at a high temperature or is subject to high shear, the desired defoaming effect cannot be expected because the emulsion is destroyed, and sometimes foaming is promoted. Also has the drawback that it cannot be used in non-aqueous systems and that the emulsion separates during long-term storage.

Therefore, it has been proposed to use an organopolysiloxane modified with a polyoxyalkylene group as the antifoaming agent (US Pat. No. 3,233,986).
However, this has the disadvantage that the effect of defoaming and defoaming is small, and a hydrophilic polysiloxane represented by dimethylpolysiloxane modified with polyoxyalkylene is used as a base oil. It has also been proposed to improve the defoaming effect by using an oil compound made of finely powdered silica (Japanese Patent Publication No. 52-19836, Japanese Patent Publication No. 52-22638, and Japanese Patent Publication No. 55-230).
No. 84), but those using a long-chain alkyl group and a polyoxyalkylene co-modified organopolysiloxane as a base oil have also been proposed (see Japanese Examined Patent Publication No. 58-58126), but these are not available with fine powder silica alone. Is difficult to stably disperse in dimethylpolysiloxane, when high temperature or mechanically strong shearing force is applied for a long time,
There is a disadvantage that silica aggregates or separates during dilution or long-term storage.

[0004]

Therefore, in order to improve the dispersibility of dimethylpolysiloxane and silica,
It has also been proposed to subject the silica surface to a silazane treatment to make it hydrophobic, but in this case, the defoaming property may be lowered depending on the treatment amount, and this is disadvantageous in that this adjustment is difficult. Regarding the defoaming agent, the present inventors have also limited polyoxyalkylene-modified organopolysiloxane, a foam inhibitor component composed of dimethyl silicone oil and fine powder silica, polyoxyethylene-polyoxypropylene copolymer and We have proposed a foam inhibitor consisting of dimethyl silicone oil in which both ends of the molecular chain are blocked with hydroxyl groups (see Japanese Patent Application No. 2-414678), which can solve the above-mentioned drawbacks considerably. Although you can
This still has the disadvantage that the dispersibility and defoaming properties of silica are insufficient.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a suds suppressor which solves these disadvantages, which comprises A) the general formula

Embedded image [Wherein G ¹ is a group selected from R ¹ , G ² or G ³ , G ² , G ³
The formula (CH ₂₎ a molecular weight of ^{_{500 ~3,000 r -O- (R 2 O}} ) s Q (R 2 is an ethylene group and a propylene group, Q is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, an acetyl group, Monovalent organic group selected from isocyanic acid group, r is 2 to 6 and s is 5 to 50)
In the group represented by, G ² is an ethyleneoxy group in the (R ² O) group.
10 to 30 mol%, G ³ has an ethyleneoxy group in the (R ² O) group of 65
~ 85 mol%, G ² / G ³ (molar ratio) is 0.3 / 1 ~ 3
/ 1, R ¹ is a monovalent hydrocarbon group having 3 to 20 carbon atoms, a is 0 or 1, m and n are positive numbers of 1 to 30, p is 10 to 100, and q is 1
To a positive number of 10] polyoxyalkylene-modified silicone oil 30 to 80% by weight B) Viscosity at 25 ℃ is 10 to
It consists essentially of 100 parts by weight of 100,000 cS dimethylpolysiloxane, (CH ₃ ) ₃ SiO _1/2 units and SiO ₂ units, with a (CH ₃ ) ₃ SiO _1/2 / SiO ₂ ratio of 0.4 / 1 to 10 parts by weight of a siloxane resin in the range of 1 to 1.3 / 1 and 5 to 50 parts by weight of a mixture of 1 to 40 parts by weight of finely divided silica, C) the molecular weight range is 500 to 3,000, and the ethyleneoxy group is 10 ~ 85
5% to 50% by weight of polyoxyethylene-polyoxypropylene copolymer, which is a mol%, D) has a viscosity of 10 to 50 at 25 ° C.
It is characterized by comprising 2 to 20% by weight of dimethylpolysiloxane in which both ends of the molecular chain of 0 cS are blocked with monohydroxydimethylsilyl groups.

That is, the present inventors have conducted various studies on methods for solving the disadvantage of the defoaming agent containing a conventionally known polyoxyalkylene-modified organopolysiloxane as a main component, and as a result, this polyoxyalkylene-modified organopolysiloxane has not been found. The amount of ethyleneoxy groups and propyleneoxy groups contained in and the molar ratio thereof are specified, and the amount of the ethyleneoxy groups and the mixture of dimethylpolysiloxane, siloxane resin and fine powder silica is specified. When the polyoxyethylene-polyoxypropylene copolymer described above and a linear dimethylpolysiloxane whose molecular chain end is blocked with a monohydroxydimethylsilyl group are added, the foam inhibitor obtained in this manner has dilution stability and quenching effect. It has excellent foam stability and high temperature stability. Out was.

Further, when a polysiloxane containing two kinds of polyoxyalkylene in the same molecule as described above is used as compared with a polysiloxane modified with a single polyoxyalkylene, this product is excellent in dilution. It was confirmed that when the siloxane resin was added to the compound consisting of dimethylpolysiloxane and powdered silica, it exhibited excellent defoaming durability and defoaming property, as well as stability and high temperature stability. The present invention has been completed by proceeding with research on types, compounding ratios, and the like. This will be described in more detail below.

[0008]

The present invention relates to a foam inhibitor composition which is particularly useful for aqueous cutting oils, fiber dyeing baths, scouring baths and the like because of its excellent dilution stability, defoaming durability and high temperature stability. Yes, this foam control composition has A) the general formula described above.
(1) polyoxyalkylene-modified silicone oil, B) dimethylpolysiloxane and (CH ₃ ) ₃ SiO _1/2 unit
A mixture comprising a siloxane resin composed of SiO ₂ units and finely divided silica, C) polyoxyethylene-polyoxypropylene copolymer, and D) a mixture of a predetermined amount of dimethylpolysiloxane having a hydroxyl group at the terminal of the molecular chain. It

The polyoxyalkylene-modified silicone oil as the component A) constituting the foam control composition of the present invention has the general formula

Embedded image , Where G ¹ is selected from R ¹ , G ² or G ³ ,
G ^2, G ³ is represented by the formula _{(CH 2) r -O- (R} 2 O) s -Q, R 2 is an ethylene group and a propylene group, r 2-6, preferably 2 to
3, s is 5 to 50, preferably 15 to 45, G ² is 10 to 30 mol% of ethyleneoxy group in (R ² O) group, and G ³ is (R ² O) group. 65-85 mol% of ethyleneoxy groups in
Are required to be.

When the average molecular weight of G ² and G ³ is less than 500, the effect of the alkyleneoxy group as a hydrophilic group is not sufficiently exerted, and when it exceeds 3,000, the viscosity becomes too high and the dispersibility,
Since the workability becomes poor, it is necessary to set it in the range of 500 to 3,000, preferably 1,000 to 2,000. Also this
Regarding G ² and G ³ , when G ² / G ³ (molar ratio) in the formula is less than 0.3, the hydrophobic portion increases and the dispersibility deteriorates, and when it exceeds 3 the defoaming property deteriorates. It must be in the range of 3.

In the above, Q is selected from a hydrogen atom, an alkyl group having 1 to 8 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group and an octyl group, an acetyl group and an isocyanic acid group. R ¹ is a monovalent hydrocarbon group, but R ¹ is a monovalent hydrocarbon group, but if the carbon number exceeds 20, the defoaming property and the water dispersibility deteriorate, so the carbon number is 3 to 20.
When m and n are positive numbers of 1 to 30 and m + n is 3 to 40, preferably 3 to 20, and p is less than 10, the defoaming property becomes poor and the viscosity of The storage stability deteriorates due to the decrease, and when it exceeds 100, the viscosity at the time of dilution becomes high and the workability deteriorates, so 10 to 100, preferably 20
-60, and q is a positive number from 1 to 10, and this has a content of a hydrophobic moiety represented by siloxane in the molecule, that is, from the total molecular weight to G ² , G ³ The amount excluding the molecular weight of is preferably 5 to 30% by weight.

This polyoxyalkylene-modified silicone oil can be synthesized by a conventionally known method. For example, two kinds of methylpolysiloxane containing ≡SiH group and vinyl group or allyl group at the terminal of the molecular chain are used. The above polyoxyalkylene compound and an unsaturated olefin having 3 to 20 carbon atoms are subjected to an addition reaction in the presence of a platinum catalyst, or an organopolysiloxane containing an ≡SiH group and an R ¹ group is added to a vinyl group at the end of the molecular chain or The foam inhibitor composition of the present invention can be easily obtained by addition reaction of two or more polyoxyalkylene compounds having an allyl group, etc.
If the content of component (A) in 00% by weight is less than 30% by weight, the water dispersibility is poor, and if it is more than 80% by weight, a uniform and stable self-emulsifying emulsion is unlikely to be formed, so
The amount may be 80% by weight, and more preferably 50 to 70% by weight.

Next, the foam control composition of the present invention is constituted.
The composition as the component (B) is the main component for imparting the defoaming persistence to the foam inhibitor composition of the present invention, which comprises dimethylpolysiloxane and (CH ₃ ) ₃ SiO _1/2 units. And a siloxane resin consisting essentially of SiO ₂ units and finely divided silica.

The dimethylpolysiloxane used here may be linear or branched, but it is preferable that the terminal of the molecular chain is blocked with a trimethylsilyl group. This dimethylpolysiloxane should have a viscosity as low as possible from the viewpoint of ease of dispersion and workability, and it is better that the viscosity is high from the viewpoint of defoaming durability.
When the viscosity is less than 10 cS, the resulting composition has poor stability, and when the viscosity is more than 100,000 cS, the resulting composition becomes significantly thickened when diluted with water before being used as a suds suppressor composition. There is a difficulty in sex, so 10 to 10
It may be in the range of 0,000 cS, preferably 100 to 5,000 cS.

The siloxane resin used here is a known method (US Pat. Nos. 2,676,182 and 2,814,601).
No. 2,857,356, JP-A-61-195129, JP-A-63-2
It can be easily manufactured according to Japanese Patent No. 56628). This siloxane resin has a ratio of (CH ₃ ) ₃ SiO _1/2 units / SiO ₂ units of 0.4 / 1 to 1.3 / 1, which is dissolved in an organic solvent or dimethylpolysiloxane. To use as. The organic solvent or dimethylpolysiloxane is not particularly limited as long as it can stably disperse the siloxane resin, but it includes dimethylpolysiloxane having a viscosity of 0.6 to 100 cS and a boiling point of 70 at normal pressure. Examples thereof include saturated aliphatic hydrocarbons, aliphatic alcohols and aromatic hydrocarbons having a temperature of up to 300 ° C.

The dimethylpolysiloxane includes hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane,
Cyclic dimethylpolysiloxane such as dodecamethylcyclohexasiloxane, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane,
Examples are linear dimethylpolysiloxanes such as dodecamethylpentasiloxane and tetradecamethylhexasiloxane.

Examples of the saturated aliphatic hydrocarbons used here include n-heptane, cyclohexane, kerosene, isoparaffins and chlorine hydrocarbons such as trichloroethane, trichloroethylene and perchloroethylene. Aliphatic alcohols Examples thereof include ethanol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, t-butyl alcohol, isopropyl alcohol and the like, and aromatic hydrocarbons such as benzene, toluene and xylene. It is illustrated.

The finely powdered silica used here may be a known one, and may be either wet silica or dry silica. Therefore, precipitated silica, silica xerogel, fumed silica, and further its surface may be used. Those treated with an organic silyl group are shown. Specifically, Aerosil [trade name of Nippon Aerosil Co., Ltd.], Nipsil [trade name of Nihon Silica Co., Ltd.], Cabosil [trade name of Cabot Co., USA], Examples include Santocell [trade name of Monsanto Chemical Co., USA], and it is preferable that the specific surface area by BET method is 100 m ² / g or more.

The compounding ratio of the dimethylpolysiloxane, the siloxane resin and the fine powder silica is 100 to 100% by weight of dimethylpolysiloxane and 0.1 to 10 parts by weight of the siloxane resin and 1 to 40 parts by weight of the fine powder silica. And it is sufficient. If the amount of this siloxane resin is less than 0.1 part by weight, the defoaming sustainability is inferior, and if it exceeds 10 parts by weight, the water dilution stability of the resulting composition is reduced, so the content is set to 0.1 to 10 parts by weight, but more preferably Is 0.5 to 5 parts by weight.
If the amount of this finely divided silica is less than 1 part by weight, the defoaming performance will be poor, and if it is more than 40 parts by weight, the viscosity of the composition will increase and the water dispersibility will decrease, so the amount will be 1-40 parts by weight. It is more preferably 5 to 20 parts by weight.

The composition as the component B) used in the present invention is prepared by mixing the above-mentioned dimethylpolysiloxane oil, siloxane resin and fine powder silica and heat treating at room temperature to 200 ° C. It can be produced by removing it, but if the blending amount of this component B) in 100% by weight of the foam inhibitor composition of the present invention is less than 5% by weight, the defoaming performance is not sufficiently exhibited, and 50% by weight is obtained. If more is added, the system thickens, causing a problem in workability.
It is good to be in the range of 50 to 50% by weight, more preferably 10 to 30% by weight.

It also constitutes the suds suppressor composition of the present invention.
The polyoxyethylene-polyoxypropylene copolymer as the component C) serves as an emulsification aid for emulsifying and dispersing the components A), B) and the component D) described below.
If the molecular weight is less than 500, the resulting composition has poor stability over time, and if it exceeds 3,000, the viscosity increases and the dispersibility is affected.
It is required to be in the range of 3,000 to 3,000, preferably 1,500 to 2,500.

When the ethyleneoxy group contained in the component C) is less than 10 mol%, the hydrophobicity becomes so strong that the function as an emulsification aid becomes insufficient, and when it exceeds 85 mol%, the hydrophilicity becomes poor. In this case too, the function as an emulsification aid cannot be sufficiently exerted, and therefore the content of ethyleneoxy groups must be in the range of 10 to 85 mol%, preferably 30 to 70 mol%. However, if the content of this product in 100% by weight of the foam suppressor composition is less than 5% by weight, the storage stability will be poor, and if it is more than 50% by weight, the dilution stability of the composition will be poor. This is 5
It may be in the range of up to 50% by weight, more preferably 10 to 30% by weight.

The dimethylpolysiloxane as component D) constituting the foam control composition of the present invention is a linear one in which both ends of the molecular chain are blocked with monohydroxydimethylsilyl groups. This is effective as a binder for the above-mentioned A) component and B) component in the foam control composition of the present invention, and the interface between the A) component and B) component where the monohydroxydimethylsilyl group is originally less compatible. It has the function of lowering the tension and improves the compatibility of these components.
If this viscosity is less than 10 cS, it causes an oil spot, and if the viscosity is higher than 500 cS, the viscosity cannot be reduced, and the effect of its addition is insufficient, so the viscosity of this suds suppressor composition cannot be increased. Moreover, it is necessary that the viscosity is 10 to 500 cS, preferably 30 to 200 cS.

The foam inhibitor composition of the component D) is 100% by weight.
If the compounding amount is less than 2% by weight, the above-mentioned effect is not sufficiently exhibited, and if it exceeds 20% by weight, the viscosity becomes too low and the silica content precipitates, which deteriorates the storage stability over time. -20% by weight, more preferably 5-
It may be in the range of 15% by weight.

The foam control composition of the present invention has the above A) to D).
It can be obtained by mixing predetermined amounts of the components, but this may be achieved by uniformly mixing each of these components using a mixer such as a homomixer, and the mixing order is not particularly limited, but at the time of mixing You may heat in the range of 40-150 degreeC.

The foam inhibitor composition of the present invention thus obtained imparts an excellent low foaming property to the liquid to which it is added for a long period of time, and it also has excellent dispersion stability and high temperature, Since it has excellent mechanical stability under high shear and does not cause agglomeration, it can be suitably used as an antifoaming agent for aqueous cutting oils and oil agents in various dyeing processes or general paints, various oil agent internal additions. it can.

[0027]

[Examples] Examples and comparative examples of the present invention are shown below, in which the viscosity shows the measured value at 25 ° C, and the various physical properties show the measured values by the following test methods.

(Dilution Stability Test Method) 10 of foam control composition
Add 100 g of 100% aqueous dispersion to a 200 ml glass beaker and add 25
The stability over time after storage at 1 ° C for 1 day was visually evaluated as follows. ⊚: Good emulsion and oil floating are not observed. ○: There is some oil floating or silica sedimentation. Δ: A lot of oil floats and a lot of silica sedimentation.

(Defoaming test method) 100 g of a 0.2% sodium oleate aqueous solution was put into a 1,000 cc measuring cylinder,
1.0 g of 10% aqueous dispersion of suds suppressor composition (as an active ingredient
1,000 ppm) was added, and the amount of foaming (foaming amount + liquid amount) after 5 minutes was measured at 25 ° C. by an air bubbling method in which air was blown at 1.0 liter / min through a glass dephasor stone.

Example 1 Component A) Average composition formula

Embedded image 650 g of polyoxyalkylene-modified silicone oil with a viscosity of 950 cS

Component B) Dimethyl silicone oil having a viscosity of 1,000 cS (B-
1) 439 g, dimethyl silicone oil (B-2) with a viscosity of 100 cS 439 g, average particle size 1.4 μm and specific surface area
100 g of wet silica (B-3) which is 300 m ² / g and (C
H ₃ ) ₃ SiO _1/2 / SiO ₂ ratio of 0.58 / 1 siloxane resin
In a glass 2 liter flask, 42 g of 60% toluene solution (B-4) was distilled under reduced pressure to remove low boiling substances at 100 mmHg at 120 ° C, heat treated at 150 ° C for 3 hours, and mixed with a homomixer 150g.

Component C) Formula

Embedded image 150 g of a polyoxyethylene-polyoxypropylene copolymer having a viscosity of 250 cS, component D) 80 g of a linear dimethyl silicone oil having a viscosity of 56 cS and having molecular chain ends blocked with silanol groups, Mix the above components A) to D) with a homomixer for 5 minutes to 10 minutes.
The foam inhibitor composition a) was adjusted by stirring for minutes, and the dilution stability and defoaming property of this composition were examined. As a result, the results shown in Table 1 below were obtained.

Example 2 As component B), 439 g of (B-1) in Example 1,
(B-2) 439 g, (B-3) 100 g and (CH _{3) 3} SiO
60% of siloxane resin with a _1/2 / SiO ₂ ratio of 0.7 / 1
Example 1 except that 42 g of a toluene solution (B-5) was used
Example 1 with components A), C) and D) used in
A foam inhibitor composition (b) was prepared in the same manner as in (1) above, and its dilution stability and defoaming property were examined. As a result, the results shown in Table 1 below were obtained.

Example 3 As component B), 439 g of (B-1) in Example 1 (B)
-2) 439g, (B-3 ) 100g and _{(CH 3) 3 SiO 1/2 /} SiO 2
Was treated as in Example 1 with components A), C) and D) used in Example 1, except that 42 g of a 60% toluene solution of a siloxane resin (B-6) having a ratio of 0.74 / 1 was used. The foam inhibitor composition C) was prepared and examined for dilution stability and defoaming property, and the results shown in Table 1 below were obtained.

Example 4 Instead of (B-4) in Example 1 as the component B),
Components A) and C) used in Example 1 except that 42 g of a 60% toluene solution of a siloxane resin (B-7) having a (CH ₃ ) ₃ SiO _1/2 / SiO ₂ ratio of 0.85 / 1 was used. , D) with Example 1
A foam inhibitor composition d) treated in the same manner as in Example 1) was prepared, and its dilution stability and defoaming property were examined.
The result as shown in was obtained.

Example 5 As component B), instead of (B-4) of Example 1, (CH ₃ ) ₃
60% of siloxane resin with a ratio of SiO _1/2 / SiO ₂ of 1.1 / 1
A foam control composition (e) was prepared by treating in the same manner as in Example 1 with the components A), C) and D) used in Example 1 except that 42 g of a toluene solution (B-8) was used. When the dilution stability and defoaming property of the product were examined, the results shown in Table 1 below were obtained.

Example 6 Instead of (B-4) of Example 1 as the component B), (CH ₃ ) ₃
60% of siloxane resin with a SiO _1/2 / SiO ₂ ratio of 1.15 / 1
A foam inhibitor composition was prepared by performing the same treatment with the same components as in Example 1 except that 42 g of a toluene solution (B-9) was used, and the dilution stability and defoaming property of this product were examined. As a result, the results shown in Table 1 described later were obtained.

Example 7 As component B), instead of (B-4) of Example 1, (CH ₃ ) ₃
60% of siloxane resin with a SiO _1/2 / SiO ₂ ratio of 1.3 / 1
Octamethylcyclotetrasiloxane solution (B-10) 42
A foam inhibitor composition g) was prepared by performing the same treatment with the same components as in Example 1 except that g was used, and its dilution stability and defoaming property were examined. The result as shown in was obtained.

Comparative Example 1 As component B), 450 g of (B-1) in Example 1 (B)
-2) Same as Example 1 with components A), C), and D) used in Example 1, except that 450 g and (B-3) 100 g were used but no siloxane resin was used. Then, a foam inhibitor composition H) was prepared and its dilution stability and defoaming property were examined. As a result, the results shown in Table 1 below were obtained.

Comparative Example 2 450 g of (B-1) used in Example 1 as component B),
(B-2) 450 g (B-3) 100 g and hexamethyldisilazane (B-11) 100 g, except that the components A), C) and D) used in Example 1 were used in the same manner as in Example 1. A foam inhibitor composition (i) was prepared by treating the composition, and the dilution stability and defoaming property of this composition were examined. The results shown in Table 1 below were obtained.

Comparative Example 3 As component A), the average composition formula is

Embedded image 650 g of polyoxyalkylene-modified silicone oil having a viscosity of 1,800 cS is used, and components B), C),
D) was used in the same manner as in Comparative Example 1 and treated in the same manner as in Example 1 to prepare a suds suppressor composition n). The dilution stability and defoaming property of this product were examined. Table 1
The result as shown in was obtained.

Comparative Example 4 Component A) is the same as Comparative Example 3, and components B), C),
The same as in Example 2 was used as D), and these were treated with the same blending amount to prepare a foam inhibitor composition l). The dilution stability and defoaming property of this product were examined. The result as shown in 1 was obtained.

[0043]

[Table 1]

[0044]

The present invention relates to a suds suppressor composition, which comprises A) a polyoxyalkylene-modified silicone oil represented by the general formula (1), B) a dimethylpolysiloxane oil and a siloxane resin, as described above. Compound consisting of finely divided silica, C) Polyoxyethylene-
The present invention is characterized by comprising a polyoxypropylene copolymer and D) a dimethylpolysiloxane oil whose molecular chain ends are blocked with monohydroxydimethylsilyl groups. This is a conventionally known silicone antifoaming agent. It is superior in dilution stability, defoaming sustainability, and high-temperature characteristics compared to other products, which gives it an industrial advantage of being able to reduce the amount added, but this product is particularly superior in stability and water-based. It can be suitably used as a defoaming agent for cutting oil, various oil agents, fiber dyeing step, and scouring step.

Front page continued (72) Inventor Satoshi Kuwata 1 Hitomi, Osamu Matsuida-cho, Usui-gun, Gunma Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory (56) Reference JP-A-3-157106 (JP, A) )

Claims (1)

(57) [Claims] 1. A) General formula: [G ¹ is a group selected from R ¹ , G ² or G ³ , and G ² and G ³ are of the formula (CH ₂ ) _r -O- (R ² O) _s Q (R ² is Ethylene group and propylene group, Q is a hydrogen atom or a carbon number of 1 to
8 is a monovalent organic group selected from an alkyl group, an acetyl group and an isocyanic acid group, r is 2 to 6 and s is a group represented by 5 to 50), and G ² is a group in the (R ² O) group. 10 to 30 ethyleneoxy groups
Mol%, G ³ is 65 to 85 mol% of ethyleneoxy group in (R ² O) group, G ² / G ³ (molar ratio) is 0.3 / 1 to 3/1, R ¹
Is a monovalent hydrocarbon group having 3 to 20 carbon atoms, a is 0 or 1,
m and n are positive numbers from 1 to 30, p is from 10 to 100, and q is a positive number from 1 to 10] 30 to 80% by weight of polyoxyalkylene-modified silicone oil, B) the viscosity at 25 ° C is 10 to 100 parts by weight of 100,000 cS dimethylpolysiloxane, (CH ₃ ) ₃ SiO _1/2 units and SiO 2
Essentially consists of ₂ units and the ratio of (CH ₃ ) ₃ SiO _1/2 / SiO ₂ is
Siloxane resin 1-10 in the range of 0.4 / 1-1.3 / 1
5 to 50% by weight of a blend consisting of 1 to 40 parts by weight of finely divided silica and C) a polyoxyethylene-polyoxypropylene having a molecular weight range of 500 to 3,000 and an ethyleneoxy group of 10 to 85 mol%. Copolymer 5 to 50% by weight, D) 2 to 20% by weight of dimethylpolysiloxane whose viscosity at 25 ° C is 10 to 500 cS, both ends of which are blocked with monohydroxydimethylsilyl groups. A suds suppressor composition characterized.