JP2002058906A - Defoaming agent composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyether defoaming agent which shows an excellent defoaming property for a water washing process of water paint, especially for water washing of cationic electrodeposition painting by UF filtrate and exhibits the excellent defoaming effect even in a low temperature range of about 10 deg.C. SOLUTION: The defoaming agent composition is composed of a compound (A) which is obtained by polymerizing 30 to 45 mol of an alkylene oxide of 3-4C to a nonreducing disaccharide and which has a cloud point of 40 to 55 deg.C by butyl diglycol 25% aqueous solution method and of a compound (B) which is obtained by polymerizing 25 to 55 mol of an alkylene oxide of 2-3C to an alcohol of 2-6C having 1 to 3 hydroxyl groups and which has a cloud point of 10 to 25 deg.C. Otherwise the defoaming agent composition is composed of the compound (A), the compound (B), and a compound (C) which is obtained by polymerizing 5 to 15 mol of an alkylene oxide of 2-3C to an alkyl amine and/or an alkyl amide of >=12C and which has a cloud point of 30 to 45 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defoaming agent, and more particularly to a defoaming agent in a water-based coating process, particularly in a water-washing process carried out immediately after the electrodeposition step in cationic electrodeposition coating. The present invention relates to a novel and useful antifoaming composition capable of solving various problems.

[0002]

2. Description of the Related Art Cationic electrodeposition coatings have become essential for primer coating of automobile bodies due to their excellent rust prevention properties.
On the other hand, for economic reasons, rinsing with water to remove excess adhered paint from the surface of the substrate lifted from the electrodeposition bath is also an essential step. Further, from the viewpoint of environmental protection, it has become mainstream to use a filtrate (hereinafter, referred to as a UF filtrate) obtained by subjecting an electrodeposition bath solution to a filtration treatment with an ultrafiltration membrane in this step. The UF filtrate usually has a liquid temperature of 27 to 30 ° C., but originally has a high foaming property because it contains an activator component which is strongly foamable from a paint. In addition, pure water is used in the final step of washing, but a small amount of paint still remains on the object to be coated, and the temperature of pure water varies greatly depending on the season and drops to about 10 ° C in winter. , Foaming is severe, and as a result, a coating film defect may be caused by the foam. In the laboratory, the foaming property in the washing step with pure water is grasped by replacing it with the foaming property of the UF filtrate itself. Conventional techniques for suppressing foaming properties of UF filtrate include a molecular weight of 500 to 1
Production of electrodeposition paints using JP-B 6-45916 in which 500 polypropylene glycol is added to the UF filtrate, JP-B 6-45772 in which both ends of polyether are alkylated, and acetylene glycol series of Air Products as the Surfynol series A method of adding in advance at the time of this is known. However, these methods have a problem that the defoaming property at low temperatures is not sufficient.

[0003]

SUMMARY OF THE INVENTION The present invention solves the drawbacks of the above-mentioned conventional defoaming agents, and is excellent in a wide temperature range, particularly at low temperatures, in a water washing process for water-based paints, particularly in a water washing with a UF filtrate in electrodeposition coating. It is an object of the present invention to provide an inexpensive defoaming agent which exhibits excellent defoaming properties and is excellent in handleability.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have reached the present invention. That is, a compound (A) having a cloud point of 40 to 55 ° C. in a 25% aqueous butyldiglycol solution obtained by polymerizing 30 to 45 mol of an alkylene oxide having 3 to 4 carbon atoms to a non-reducing disaccharide, and 2-6
Alcohols having 1 to 3 hydroxyl groups to 2 to 3 carbon atoms
An antifoaming composition comprising a compound (B) having a cloud point of 10 to 25 ° C. obtained by polymerizing 25 to 55 moles of an alkylene oxide of the formula (A), the compound (A), the compound (B) and a compound having 12 or more carbon atoms. An alkylamine and / or an alkylamide is added with an alkylene oxide having 2 to 3 carbon atoms in an amount of 5-1.
Compound (C) which is polymerized by 5 mol and has a cloud point of 30 to 45 ° C.
An antifoaming composition comprising:

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the non-reducing disaccharide constituting compound (A) is defined as non-reducing maltose or lactose by chemical modification such as sucrose, trehalose and alkylation, or glucose. And a non-reducing saccharide such as fructose using a dihydric alcohol. Of these, sucrose is particularly preferred. Examples of the alkylene oxide having 3 to 4 carbon atoms to be subjected to addition polymerization to these saccharides include propylene oxide (hereinafter abbreviated as PO) and 1,2-butylene oxide (hereinafter abbreviated as BO). The number of moles of PO and BO added to these saccharides is 30 to 45 moles, preferably 32 to 43 moles.
Is a mole. If the amount is less than 30 mol or more than 45 mol, sufficient defoaming properties cannot be obtained. Of these, BO
Is from 0 to 3, and if it exceeds 3 moles, the defoaming property is reduced. The order of addition polymerization of PO and BO is not particularly limited, and the polymerization mode may be either block or random. Usually, PO is polymerized first, and then BO is polymerized.

In the present invention, the cloud point is a measure of the hydrophilicity of a nonionic surfactant. Generally, the higher the cloud point, the greater the hydrophilicity. The measuring method in the present invention conformed to "Measurement method B" in ISO 1065-1975 (E), "Ethylene oxide based nonionic surfactant-Cloud point measurement method". That is, the sample is first dissolved in a 25% by weight aqueous solution of butyl diglycol (butanol / EO 2 mol adduct) to a concentration of 10% by weight. Next, about 5 cc of this sample solution is taken in a test tube, and a thermometer is put in the test tube and gradually heated with stirring, and finally the sample solution becomes cloudy. Then slowly cool with stirring,
The temperature at which the sample solution turns from cloudy to transparent is read, and this is defined as the cloud point.

The cloud point of the compound (A) of the present invention is 40 to 55.
° C, preferably 42 to 53 ° C. Even if the cloud point exceeds 55 ° C or falls below 40 ° C, sufficient defoaming properties cannot be obtained.

In the present invention, examples of the catalyst used for addition polymerization of PO and BO to the saccharide include alkali or alkaline earth hydroxides or carbonates, and trialkylamines. Of these, potassium hydroxide, cesium hydroxide, trimethylamine and triethylamine are preferred. The amount of the catalyst used is in the range of 0.05 to 2.0% by weight, preferably 0.1 to 1.0% by weight, based on the weight of the polyether at the end of the polymerization. Usually, first, use an amine catalyst at 80 to 120 ° C. for 10 to 1
A low addition polymer of about 5 mol is produced, and then a high addition polymer is produced using a catalyst such as potassium hydroxide or cesium hydroxide.

In the present invention, examples of the alcohol having 2 to 6 carbon atoms and having 1 to 3 hydroxyl groups which constitute the compound (B) include ethanol, butanol, propylene glycol, 1,6-hexanediol, glycerin and trimethylol. Pull bread and the like can be mentioned. Of these, alcohols having 2 to 4 carbon atoms are preferable. Examples of the alkylene oxide having 2 to 3 carbon atoms to be subjected to addition polymerization include EO and PO.
O. The number of moles of these added is 25 to 55, preferably 27 to 53. The order of addition polymerization of EO and PO is not particularly limited, and the polymerization type may be either block or random. The cloud point of the compound (B) of the present invention is 10 to 25.
° C, preferably 12 to 23 ° C. If the cloud point exceeds 25 ° C. or falls below 10 ° C., sufficient defoaming properties cannot be obtained. In particular, if it exceeds 25 ° C., sufficient defoaming properties cannot be obtained at low temperatures.

In the present invention, the alkylamine and / or alkylamide having 12 or more carbon atoms forming the compound (C) is a compound having 12 or more carbon atoms and having one or more primary or secondary nitrogen atoms.
A compound having at least one compound, laurylamine, palmitylamine, stearylamine, distearylamine, oleylamine, stearylpropylenediamine, laurylamide, myristylamide, palmitylamide, stearylamide, oleylamide, polyalkylpolyamine, and a carboxylic acid. And a mixture thereof. Of these, preferred are laurylamine, palmitylamine, stearylamine, oleylamine, stearylamide and ethylenebisstearylamide, and particularly preferred are stearylamine and oleylamine.

In the present invention, the alkylamine and / or alkylamide is subjected to addition polymerization with 2 to 3 carbon atoms.
Examples of the alkylene oxide include EO and PO, with PO being preferred. The number of moles of EO and PO added is 5 to 15. Of these, the average number of moles of EO is 20% or less of the total number of moles added, and if it exceeds 20%, the defoaming power decreases. When the number of moles of the alkylene oxide added is less than 5, no defoaming property can be obtained. When it is more than 15, the defoaming property, especially the foam breaking property is reduced. EO, PO
The order of addition polymerization is not particularly limited, and the polymerization type may be either block or random. The cloud point of the compound (B) of the present invention is 30 to 45 ° C, preferably 32 to 43 ° C.
It is. Even if the cloud point exceeds 45 ° C. or falls below 30 ° C., sufficient defoaming properties cannot be obtained.

PO to alkylamine, alcohol, etc.
As a catalyst used for the addition polymerization of EO, an alkali or alkaline earth hydroxide is preferable, and potassium hydroxide is particularly preferable. The amount of the catalyst used is in the range of 0.01 to 2.0% by weight, preferably 0.05 to 1.0% by weight, based on the weight of the polyether at the end of the polymerization.

In the present invention, the addition polymerization reaction of (A), (B) and (C) may be carried out under ordinary conditions, for example, at a temperature of 60 to 170 ° C., preferably 80 to 1
50 ° C. The pressure (gauge pressure) during the polymerization is 0 to
8 kg / cm ^2, preferably 1~6kg / cm ^2. The time required for the reaction is usually 2 to 12 hours.

In the present invention, as a method for removing the catalyst from (A), (B) and (C) obtained by polymerization, for example, as described in JP-B-47-3745, an alkaline catalyst is prepared by using an acidic component. , And the resulting salt is removed by filtration, the method using an alkali adsorbent disclosed in JP-A-53-123499, Japanese Patent Publication No. 49-1435.
No. 9, a method of dissolving in a solvent and washing with water;
No. 23211, a method using an ion exchange resin, a method of neutralizing an alkaline catalyst of Japanese Patent Publication No. 52-33000 with carbon dioxide, and filtering a generated carbonate, and a method of neutralizing with various organic acids and inorganic acids. Etc., but any of them can be used.

Among the components of the antifoaming composition of the present invention, (A) has a stable defoaming property with respect to the UF filtrate, especially the defoaming in the middle stage of the defoaming test (2 to 4 minutes after the start of the defoaming test). (B) shows the defoaming property at the early stage of the defoaming test (two minutes from immediately after the start of the defoaming test) and the defoaming property at low temperature, and (C) shows the late stage of the defoaming test ( 3 after start of defoaming test
Minutes to 5 minutes). Therefore (A) /
The compounding ratio based on the weight of (B) / (C) is 40 to 85/1.
5-35 / 0-25. If (A) is less than 40, the balance of the defoaming property is lost, and no effective defoaming property is exhibited.

The antifoaming composition of the present invention may be added directly to the UF filtrate, or may be added in advance to a resin component forming a cationic electrodeposition paint, or may be a resin component, a pigment paste component and water. May be added when producing an electrodeposition paint. In addition, (A), (B) and (C) may be added in a state of being previously blended, or may be added individually. When adding individually, the order of addition is not particularly limited. Also,
The total amount of the antifoaming composition of the present invention added to the UF filtrate is usually 100 to 3,000 ppm, preferably 200 to 3,000 ppm.
2,000 ppm.

[0017]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. Table 1 shows the results of the defoaming test. In addition, the part in an Example means a weight part.

[Production of cationic electrodeposition paint for defoaming test]
The cationic electrodeposition paint for obtaining the UF filtrate for the defoaming test is 1,
An emulsion containing a resin component, 2, a pigment paste containing a pigment component, and 3, deionized water.

Production Example 1 Production of emulsion containing resin component 950 parts of a commercially available bisphenol A type epoxy resin (epoxy equivalent: 950), methyl isobutyl ketone (MI
BK) 240 parts, N-methylethanolamine 55 parts,
75% of MIBK diketimine compound of diethylenetriamine
% Of a MIBK solution containing 80% by weight is defined as an emulsion-1 component. 980 parts of isophorone diisocyanate, 600 parts of MIBK, 1 part of dibutyltin dilaurate and 225 parts of trimethylolpropane
After reacting at 0 ° C. or lower, 430 parts of methyl ethyl ketoxime were added at the same temperature, and n-butanol 3
The fully blocked polyisocyanate resin solution to which 5 parts were added was designated as emulsion-2 component. The above emulsion-
To 1320 parts of one component and 570 parts of the emulsion-2 component, 100 parts of ethylene glycol monobutyl ether and 550 parts of 6% acetic acid water were added to neutralize, and further deionized water 220
After adding 0 parts to make uniform, low-boiling substances were distilled off under reduced pressure to produce an emulsion having a solid content of 35%. Note that a commercially available deionized water was used.

Production Example 2 20 parts of bisphenol A type epoxy-based quaternary ammonium salt pigment dispersion resin (solid content: 50%), titanium dioxide 32
Parts, 15 parts of kaolin, 1.5 parts of basic lead silicate, 1 part of carbon black and 30.5 parts of deionized water were dispersed in a steel ball mill to a particle size of 10 μm or less to obtain a pigment paste.

[Defoaming test method]
It carried out as follows based on the method described in 45916 gazette. 400 parts of the emulsion obtained in Production Example 1 (In the case of Surfynol 104, the defoaming agent of Comparative Example 11, a methanol solution of Surfynol 104, 50% of the active ingredient
1.5 parts of the product are added and stirred for 15 minutes. Surfynol 104 is 750 ppm by weight with respect to the coating composition), 500 parts of deionized water is charged, and the mixture is mixed uniformly at room temperature. To this, 100 parts of the pigment paste obtained in Production Example 2 is added and uniformly mixed at room temperature to obtain an electrodeposition paint. Thereafter, stirring is continued for 5 hours at 40 ° C. in an unsealed state, and deionized water is additionally supplemented for the reduced weight. Approximately 1.5 liters of the paint thus obtained was adjusted to a temperature of 28 ° C. or less, a UF module manufactured by Asahi Kasei Corporation,
Ultrafiltration is carried out with KCP-1010 to obtain 150 mL of UF filtrate. An antifoaming agent is added to the filtrate so as to have a weight ratio of 500 ppm, and the mixture is stirred uniformly. (If the antifoaming agent was not added in Comparative Example 1, the step of adding the antifoaming agent was omitted.) The temperature of this UF filtrate was adjusted to 28 ° C and 10 ° C. Put 100mL into 4 Ford Cup, 500mL placed 1m below
Drop into glass graduated cylinder to generate bubbles. The amount of foam remaining in the measuring cylinder (mL) is measured over 5 minutes. The results are shown in Table 1.

Production Example 3 In a pressure vessel capable of heating, stirring and dripping, Sanix polyol RP-410A [13 mol adduct of sucrose / PO, manufactured by Sanyo Chemical Industries, Ltd., average hydroxyl value 410, average molecular weight 1095] 1095 And 6.0 parts of potassium hydroxide [special reagent grade, the same applies hereinafter], and after dehydration at 130 ° C. under reduced pressure, 22 mols of PO and 1276 parts of PO were dropped at 100 to 120 ° C. to carry out addition polymerization. . The required reaction time was about 8 hours. Next, after adding 6 parts of ion-exchanged water at 90 ° C., 50 parts of Kyoward 600 (manufactured by Kyowa Chemical Co., Ltd.) as an alkali adsorbent was added, and the mixture was stirred at the same temperature for 1 hour. Then, at the same temperature, 2 Filter paper [Toyo Filter Paper Co., Ltd.
The catalyst is adsorbed and removed under reduced pressure.
After dehydration treatment at 20 ° C for 2 hours, (A-1) having a sucrose / PO35 mol adduct and a cloud point of 50.2 ° C was obtained.

Production Example 4 In the same manner as in Production Example 3, sucrose / 30 mol of PO / BO1
A molar adduct, (A-2) having a cloud point of 54.2 ° C, was obtained.

Preparation Example 5 In the same manner as in Preparation Example 3, sucrose / PO43 mol adduct
(A-3) having a cloud point of 42.3 ° C was obtained.

Production Example 6 Modified n-butyl maltose was obtained from maltose and n-butanol (1 mol) by the method described in JP-A-63-84637. Then Sanix polyol RP-41
Polymerization treatment was performed in the same manner as in Production Example 3 using a mixture having a weight ratio of 0A / n-butyl modified maltose of 3/1, and sucrose and n-
(A-4) having an average molar number of addition of PO of 33 and a cloud point of 52.5 ° C was obtained in a mixture of about 1: 1 butyl-modified maltose.

Production Example 7 In the same manner as in Production Example 3, sucrose / PO 20 mol adduct
(A-5) having a cloud point of 60.6 ° C was obtained.

Production Example 8 In the same manner as in Production Example 3, sucrose / PO 50 mol adduct
(A-6) having a cloud point of 38.2 ° C was obtained.

Production Example 9 76 parts of propylene glycol and 4.0 parts of potassium hydroxide were added to a pressure-resistant vessel capable of being heated, stirred and dropped, and after dehydration under reduced pressure at 80 ° C., 27 mol of PO and 1566 parts of PO were added. 10
Addition polymerization was carried out by dropping at 0 to 120 ° C. The required reaction time was about 10 hours. Next, after adding 6 parts of ion-exchanged water at 90 ° C., 80 parts of Kyoward 600 was added,
The mixture was stirred at the same temperature for 1 hour. Then, at the same temperature, 2
The mixture was filtered using a filter paper and dehydrated under reduced pressure at 120 ° C. for 2 hours to obtain a propylene glycol / PO 27 mol adduct (B-1) having a cloud point of 24.0 ° C.

Production Example 10 Glycerin 92 was placed in a pressure vessel capable of heating, stirring and dropping.
And 6.0 parts of potassium hydroxide, and after dehydration at 90 ° C. under reduced pressure, 46 mol of PO and 2668 parts of 100 to 12 parts were added.
It was added dropwise at 0 ° C. to effect addition polymerization. Required reaction time is about 13
It was time. Next, 6 parts of ion-exchanged water was added at 90 ° C., and then 90 parts of Kyoward 600 was added, followed by stirring at the same temperature for 1 hour. Then, at the same temperature, 2 Filtration using filter paper and dehydration treatment under reduced pressure at 120 ° C. for 2 hours, glycerin / PO 46 mol adduct, cloud point 12.7 ° C.
(B-2) was obtained.

Production Example 11 n-Butanol 7 was placed in a pressure vessel capable of heating, stirring and dropping.
4 parts and 5.0 parts of potassium hydroxide were added thereto, and after dehydration under reduced pressure, 1 part 44 parts of EO and then 38 parts 220 mol of PO
4 parts were added dropwise at 100 to 120 ° C. to carry out addition polymerization. The required reaction time was about 12 hours. Next, after adding 5 parts of ion-exchanged water at 90 ° C.,
And stirred at the same temperature for 1 hour. Then, at the same temperature, 2 Filtered using filter paper, and further dehydrated under reduced pressure at 120 ° C. for 2 hours to obtain n-butanol / EO 1 mol /
A 38 mol PO adduct (B-3) having a cloud point of 15.6 ° C. was obtained.

Production Example 12 In the same manner as in Production Example 9, propylene glycol / PO5
(B-4) having an adduct of 8 mol and a cloud point of 9.0 ° C. was obtained.

Production Example 13 In the same manner as in Production Example 11, a butanol / PO22 mol adduct (B-5) having a cloud point of 27.4 ° C. was obtained.

Production Example 14 To a pressure-resistant container capable of heating, stirring and dripping, 269 parts of stearylamine and 1.5 parts of potassium hydroxide were added, and after dehydration under reduced pressure at 120 ° C., 44 parts of 1 mol of EO, 4 mol parts of 8 mol of PO was added dropwise at 100 to 120 ° C. to carry out addition polymerization. The required reaction time was about 10 hours. Then 9
After adding 2 parts of ion-exchanged water at 0 ° C, Kyoward 6
00 was added thereto and stirred at the same temperature for 1 hour. Then, at the same temperature, 2 Filtered using filter paper, and further dehydrated under reduced pressure at 120 ° C. for 2 hours to obtain stearylamine /
1 mol of EO / 8 mol of PO adduct, (C) with a cloud point of 36.5 ° C.
-1) was obtained.

Production Example 15 In the same manner as in Production Example 14, stearylamide / PO 6 mol adduct (C-2) having a cloud point of 40.3 ° C. was obtained.

Production Example 16 In the same manner as in Production Example 14, an oleylamine / PO 12 mol adduct (C-3) having a cloud point of 32.7 ° C. was obtained.

Production Example 17 In the same manner as in Production Example 14, an ethylene bisstearylamide / 2 mol EO / 8 mol PO8 adduct (C-4) having a cloud point of 31.4 ° C. was obtained.

Production Example 18 In the same manner as in Production Example 14, stearylamine / PO16
A molar adduct, (C-5) with a cloud point of 27.8 ° C, was obtained.

Production Example 19 In the same manner as in Production Example 14, 2-ethylhexylamine /
A PO4 molar adduct, (C-6) with a cloud point of 47.5 ° C, was obtained.

Example 1 (A-1) / (B-1) / (C-1) = 50/30/2
No. 0 antifoaming composition was prepared and subjected to an antifoaming test.

Example 2 (A-2) / (B-2) / (C-2) = 70/23/7
Was prepared and subjected to a defoaming test.

Example 3 An antifoaming composition (A-3) / (B-3) = 75/25 was prepared and subjected to an antifoaming test.

Example 4 (A-4) / (B-2) / (C-3) = 52/33/1
The defoamer composition of No. 5 was manufactured and subjected to the defoaming test.

Example 5 (A-1) / (B-3) / (C-4) = 75/17/1
The antifoaming composition of No. 8 was produced and subjected to an antifoaming test.

Example 6 (A-2) / (B-2) / (C-3) = 40/35/2
The defoamer composition of No. 5 was manufactured and subjected to the defoaming test.

Example 7 (A-3) / (B-1) / (C-4) = 80/15/5
Was prepared and subjected to a defoaming test.

Comparative Example 1 [Defoaming Test] An antifoaming test was conducted without adding the defoaming agent described.

Comparative Example 2 (A-1) was subjected to a defoaming test.

Comparative Example 3 (B-2) was subjected to a defoaming test.

Comparative Example 4 (C-3) was subjected to a defoaming test.

Comparative Example 5 (A-5) / (B-4) / (C-5) = 60/20/2
No. 0 antifoaming composition was prepared and subjected to an antifoaming test.

Comparative Example 6 (A-6) / (B-5) / (C-6) = 60/20/2
No. 0 antifoaming composition was prepared and subjected to an antifoaming test.

Comparative Example 7 (A-1) / (B-4) / (C-6) = 60/20/2
No. 0 antifoaming composition was prepared and subjected to an antifoaming test.

Comparative Example 8 (A-1) / (B-3) / (C-2) = 30/40/3
No. 0 antifoaming composition was prepared and subjected to an antifoaming test.

Comparative Example 9 An antifoaming composition (A-2) / (C-1) = 80/20 was produced and subjected to an antifoaming test.

Comparative Example 10 An antifoaming composition (A-1) / (B-5) = 70/30 was produced and subjected to an antifoaming test.

Comparative Example 11 A UF filtrate obtained from an electrodeposition paint using Surfynol 104 as an antifoaming agent was subjected to an antifoaming test.

[0057]

[Table 1]

[0058]

The defoamer composition according to the present invention exhibits excellent defoaming properties with respect to the water-washing step in water-based coatings, particularly in the UF filtrate washing step immediately after the electrodeposition step in cationic electrodeposition coating, Further, since the defoaming effect is excellent even in a temperature range as low as about 10 ° C., it is useful for improving operation stability and the like in an electrodeposition coating process.

Claims (7)

[Claims] 1. A compound (A) in which a non-reducing disaccharide is polymerized with 30 to 45 mol of an alkylene oxide having 3 to 4 carbon atoms, and has a cloud point of 40 to 55 ° C. by a 25% aqueous solution of butyldiglycol. An alcohol having 2 to 6 carbon atoms and having 1 to 3 hydroxyl groups is polymerized with 25 to 55 moles of an alkylene oxide having 2 to 3 carbon atoms, and a compound (B) having a cloud point of 10 to 25 ° C. Foam composition. 2. A compound (A) having 30 to 45 moles of an alkylene oxide having 3 to 4 carbon atoms polymerized on a non-reducing disaccharide and having a cloud point of 40 to 55 ° C. by a 25% aqueous solution of butyldiglycol. Compound (B) having 25 to 55 moles of an alkylene oxide having 2 to 3 carbon atoms polymerized on an alcohol having 2 to 6 carbon atoms and having 1 to 3 hydroxyl groups, and having a cloud point of 10 to 25 ° C. An antifoaming composition comprising a compound (C) obtained by polymerizing 5 to 15 moles of an alkylene oxide having 2 to 3 carbon atoms to 12 or more alkylamines and / or alkylamides and having a cloud point of 30 to 45 ° C. 3. The antifoaming composition according to claim 1, wherein the compound (A) is obtained by polymerizing sucrose with propylene oxide. 4. The compound (B) obtained by polymerizing propylene oxide on an alcohol having 2 to 4 carbon atoms.
The antifoaming composition according to any one of the above. 5. The antifoaming composition according to claim 2, wherein the compound (C) is obtained by polymerizing an alkylene oxide having 2 to 3 carbon atoms with a monoalkylamine having 12 to 18 carbon atoms. 6. The antifoaming composition according to claim 1, wherein the compounding ratio based on the weight of (A) / (B) / (C) is from 40 to 85/15 to 35/0 to 25. object. 7. The antifoaming composition according to claim 1, which is an antifoaming agent for a water washing step in a water-based paint.