JP2010059015A - Foaming agent for cement composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foaming agent for a cement composition which has high foamability and exhibits excellent foam stability not only in cement milk, mortar, and concrete, but also in fly ash mortar. <P>SOLUTION: The foaming agent for a cement composition contains a compound A represented by formula (1), a compound B represented by formula (2), and a compound C represented by formula (3). In formula (1), R<SP>1</SP>represents a 8-30C alkyl, alkenyl or alkylphenyl group; Y represents hydrogen or methyl; groups X and X' each represent a hydrogen atom, a metal atom, or ammonium; and m represents an integer of 0-5. In formula (2), R<SP>2</SP>is the residue obtained from a 6-20C fatty acid by removing the carboxyl group. In formula (3), R<SP>3</SP>represents a 8-20C hydrocarbon group; Y represents hydrogen or a methyl group; and n represents an integer of 0-5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a foaming agent for a cement composition capable of introducing fine and stable bubbles into a cement composition such as concrete, mortar, cement milk and the like.

  Conventionally, sulfate anionic surfactants have been widely used as foaming agents for introducing bubbles into cement blends such as cement milk, mortar and concrete (Patent Document 1).

  However, the above foaming agents are not always satisfactory in terms of the long-lasting air bubbles when they are mixed with the cement formulation. In addition, when a high expansion ratio is required, there is a problem that the required expansion ratio is not reached.

  In recent years, fly ash, which is coal ash generated when coal is burned in a thermal power plant, has been actively used. One of them is bubble fly ash mortar in which fly ash is blended into cement and bubbles are introduced therein. However, when the above-mentioned foaming agent is used in a bubble fly ash mortar, the required performance is not obtained due to severe defoaming.

Therefore, there is a demand for a foaming agent that exhibits stable performance not only in cement milk, mortar and concrete but also in fly ash mortar.
Japanese Patent Laid-Open No. 03-050168

  The present invention has been made in view of the above, and has a high foaming property. The foaming agent for cement composition exhibits excellent cell stability not only in cement milk, mortar and concrete but also in fly ash mortar. The purpose is to provide.

  As a result of repeated researches to solve the above problems, the present inventors have found that the compound A represented by the following general formula (1), the compound B represented by the general formula (2), and the general formula (3) When the foaming agent containing the compound C represented by) was used, the intended purpose was achieved and the present invention was achieved.

  That is, the foaming agent for a cement composition of the present invention includes a compound A represented by the following general formula (1), a compound B represented by the general formula (2), and a compound represented by the general formula (3). It shall contain C.

但し、式（１）において、Ｒ^１，Ｙ，Ｘ，Ｘ´及びｍは以下の通りである。
Ｒ^１：炭素数８〜３０のアルキル基、アルケニル基またはアルキルフェニル基
Ｙ：水素またはメチル基
Ｘ，Ｘ´：水素原子、金属原子、またはアンモニウム
ｍ：０〜５の整数

However, in the formula ^{(1), R 1, Y} , X, X' , and m are as follows.
R ¹ : alkyl group having 8 to 30 carbon atoms, alkenyl group or alkylphenyl group Y: hydrogen or methyl group X, X ′: hydrogen atom, metal atom, or ammonium m: integer of 0 to 5

但し、式（２）において、Ｒ^２は炭素数６〜２０脂肪酸からカルボキシル基を除いた残基である。

However, in formula (2), ^{R 2} is a residue obtained by removing carboxyl group from a few 6-20 fatty atoms.

但し、式（３）において、Ｒ^３，Ｙ及びｎは以下の通りである。
Ｒ^３：炭素数８〜２０の炭化水素基
Ｙ：水素またはメチル基
ｎ：０〜５の整数

However, in Formula (3), R < ³ >, Y and n are as follows.
R ³ : hydrocarbon group having 8 to 20 carbon atoms Y: hydrogen or methyl group n: integer of 0 to 5

  In the above, the mixing ratio of Compound A and Compound B is a pure weight ratio, Compound A / Compound B = 90/10 to 10/90, and the mixing ratio of Compound C to Compound A and Compound B is pure. It is preferable that the weight ratio is (compound A + compound B) / compound C = 95 / 5-30 / 70.

  The foaming agent for a cement composition of the present invention can be used for a cement composition containing fly ash.

  The foaming agent for a cement composition of the present invention has a high foaming property, and exhibits excellent cell stability not only in cement milk, mortar and concrete but also in fly ash mortar.

  In particular, by setting the mixing ratio of the compound A, the compound B and the compound C to a specific ratio in a pure weight ratio, sufficient foaming properties can be obtained, and even more excellent bubble stability can be obtained. Be able to.

  Next, embodiments of the present invention will be described in detail. Hereinafter, unless otherwise specified, “parts” represents parts by weight.

  The foaming agent for a cement composition of the present invention essentially comprises the compound A represented by the general formula (1), the compound B represented by the general formula (2), and the compound C represented by the general formula (3). Ingredients.

Compound A is represented by the following general formula (1):

R ¹ in Formula (1) is a linear or branched alkyl group, alkenyl group, or alkylphenyl group having 8 to 30 carbon atoms.

When R ¹ is an alkyl group or an alkenyl group, the carbon number is preferably 8-20. Examples include octyl, nonyl, decyl, undecyl, lauryl (dodecyl), tridecyl, myristyl (tetradecyl), pentadecyl, cetyl (hexadecyl), heptadecyl, stearyl (octadecyl), nonadecyl, eicosyl, oleyl, linoleyl, and linolenyl. . These may be used alone or in combination of two or more.

  Of these, straight chain is preferable to branching from the viewpoint of foaming power, and decyl, undecyl, dodecyl (lauryl), tridecyl, and tetradecyl (myristyl) are more preferable.

When R ¹ is an alkylphenyl group, the alkyl group in the alkylphenyl group preferably has 4 to 12 carbon atoms. Among these, a straight chain is preferable to a branch from the viewpoint of foaming power, and an alkylphenyl group having an alkyl group having 6 to 10 carbon atoms is more preferable.

  Specific examples of the compound represented by the general formula (1) include (polyoxyethylene) octylsulfosuccinate, (polyoxypropylene) octylsulfosuccinate, (polyoxyethylene) decylsulfosuccinate, (Polyoxypropylene) decyl sulfosuccinate, (polyoxyethylene) lauryl sulfosuccinate, (polyoxypropylene) lauryl sulfosuccinate, (polyoxyethylene) myristyl sulfosuccinate, (polyoxypropylene) myristyl sulfosuccinate, ( (Polyoxyethylene) stearyl sulfosuccinate, (polyoxypropylene) stearyl sulfosuccinate, (polyoxyethylene) oleyl sulfosuccinate, (polyoxypropylene) oleyl sulfosuccinate, (polyoxyethylene) N) octylphenylsulfosuccinate, (polyoxypropylene) octylphenylsulfosuccinate, (polyoxyethylene) nonylphenylsulfosuccinate, (polyoxypropylene) nonylphenylsulfosuccinate, (polyoxyethylene) dodecylphenylsulfosuccinate Salt, (polyoxypropylene) dodecylphenyl sulfosuccinate, (polyoxyethylene) styrenated phenyl sulfosuccinate, (polyoxypropylene) styrenated phenyl sulfosuccinate, and the like. These may be used alone or in combination of two or more.

The repeating unit represented by the following formula represents oxyethylene or oxypropylene, and may be any one kind or a mixture. m is 0-5. This is because if m exceeds 5, the foaming power decreases.

  Furthermore, in the compound A, X and X ′ represent a hydrogen atom, a metal atom, or ammonium. Examples of the metal atom include alkali metal atoms such as lithium, sodium and potassium, alkaline earth metal atoms such as magnesium and calcium (however, since alkaline earth metal atoms are usually divalent, 1/2), etc. Examples of ammonium include ammonia, methylamine, dimethylamine, ethylamine, diethylamine, (iso) propylamine, di (iso) propylamine, monoethanolamine, N-methylmonoethanolamine, and N-ethylmonoethanol. Amine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, 2-amino-2-methyl-1,3-propanediol, aminoethylethanolamine, N, N, N ′, N′— Tetrakis (2-Hi Rokishipuropiru) ammonium, such as ethylenediamine. X and X ′ may be the same or different, and two or more of the above-described ones can be mixed and used.

  Among these compounds A represented by the general formula (1), (polyoxyethylene) lauryl sulfosuccinate is particularly preferable. In this case, the chain length of polyoxyethylene is preferably such that the average number of repeating units is 0-3.

Next, compound B is represented by the following general formula (2);

In the formula (2), R ² is a residue obtained by removing a carboxyl group from a fatty acid having 6 to 20 carbon atoms.

  Examples of fatty acids include caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and the like. Moreover, the mixed fatty acid obtained from natural fats and oils, such as coconut oil, balm oil, balm kernel oil, castor oil, soybean oil, rapeseed oil, beef tallow, and lard, may be sufficient.

  Of these, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, and coconut oil fatty acid are more preferable from the viewpoint of foaming ability.

  Specific examples of the compound represented by the general formula (2) include amidopropyl caprylate, amidopropyl caprylate, amidopropyl betaine laurate, amidopropyl myristate, amidopropyl palmitate, stearic acid Examples include amidopropyl betaine, oleic acid amidopropyl betaine, and coconut oil fatty acid amidopropyl betaine. Moreover, these may be used independently and can also be used in mixture of 2 or more types.

Further, Compound C is represented by the following general formula (3);

  The compound C used together with the compounds A and B is a specific higher alcohol and an alkylene oxide adduct of the higher alcohol. The specific higher alcohol is a linear or branched natural alcohol or synthetic alcohol. Moreover, the alkylene oxide adduct of the specific higher alcohol is obtained by adding an alkylene oxide to these higher alcohols.

In the general formula (3), ^{R 3} is a hydrocarbon group having 8 to 20 carbon atoms, preferably a hydrocarbon group having 10 to 18 carbon atoms. That is, if the carbon number of the hydrocarbon group represented by R ³ is as small as less than 8, the stability of the bubbles deteriorates. Conversely, if the carbon number exceeds 20 and the solubility in water is insufficient. Product separation is likely to occur.

  Specific examples of the specific higher alcohol include octyl alcohol, decyl alcohol, lauryl alcohol (dodecyl alcohol), myristyl alcohol (tetradecyl alcohol), cetyl alcohol (hexadecyl alcohol), stearyl alcohol (octadecyl alcohol), and oleyl. Alcohols and the like as well as synthetic alcohols can be mentioned. These may be used alone or in combination of two or more.

  Examples of the alkylene oxide added to the specific higher alcohol include ethylene oxide and propylene oxide, and the number of moles added is preferably 0 to 5 mol on average including those not added with alkylene oxide (the higher alcohol). More preferably, the average is 0 to 3 mol. When the added mole number of alkylene oxide exceeds 5 moles on average, the stability of the bubbles is lowered.

  In the compound C, particularly from the viewpoint of stability of bubbles, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, and adducts thereof with an alkylene oxide (average number of added moles of 0 to 3 mol) are used. preferable.

  Thus, the foaming agent for a cement composition according to the present invention comprises compound A and compound B, which are foaming components, and compound C as essential components, and the mixing ratio of compound A and compound B is as follows: The pure weight ratio is preferably set in the range of Compound A / Compound B = 90/10 to 10/90, more preferably in the range of Compound A / Compound B = 70/30 to 30/70.

  The mixing ratio of compound C to compound A and compound B (total amount of both) is a pure weight ratio, and is set in the range of (compound A + compound B) / compound C = 95/5 to 30/70. Is preferable, and (Compound A + Compound B) / Compound C = 80/20 to 50/50 is more preferable.

  That is, in the mixing ratio of compound A and compound B, when the ratio of compound A exceeds 90, the fluidity of the slurry in a state where foam and cement are mixed is lowered, while when compound A is less than 10, Bubble stability is reduced.

  Moreover, in the mixing ratio of compound A + compound B and compound C, when the ratio of compound C exceeds 70, foaming properties are lowered, whereas when the ratio of compound C is less than 5, bubble stability is lowered.

  In the foaming agent for a cement composition of the present invention, if necessary, a surfactant other than Compound A, Compound B, and Compound C, a water-soluble organic solvent, a fatty acid (salt), a water-soluble polymer, a water reducing agent, A dispersant may be used.

  Examples of combined surfactants other than Compound A and Compound B include, as anionic surfactants, alkyl sulfate esters, polyoxyalkylene alkyl ether sulfates, alkane sulfonates, α-olefin sulfonates, and the like. . Examples of nonionic surfactants include polyoxyalkylene alkyl ethers and fatty acid alkanolamides. Examples of amphoteric surfactants include imidazolium betaine type amphoteric surfactants, aminodipropyl betaine type amphoteric surfactants, and amine oxide type amphoteric surfactants. These may be used alone or in combination of two or more.

  Of these, alkyl sulfate ester salts, polyoxyalkylene alkyl ether sulfates, alkane sulfonates, α-olefin sulfonates, and imidazolium betaine type amphoteric surfactants are preferably used. Stability can be further improved.

  As a compounding quantity of these surfactant, 0-100 parts are preferable with respect to a total of 100 parts of the compound A, the compound B, and the compound C, Most preferably, you may be 0.1-50 parts.

  As the water-soluble organic solvent, cellosolve solvents, carbitol solvents, polyoxyethylene lower alkyl ethers having 3 to 10 added moles of ethylene oxide, and diols can be used.

  Examples of water-soluble organic solvents include cellosolve solvents such as methyl cellosolve, ethyl cellosolve, n-propyl cellosolve, n-butyl cellosolve, isobutyl cellosolve, and phenyl cellosolve, and carbitol solvents such as ethyl carbitol and butyl carbitol. Examples of the polyoxyethylene lower alkyl ether include polyoxyethylene (3 mol) methyl ether, and examples of the diol include ethylene glycol, propylene glycol, diethylene glycol, and polyethylene glycol. These may be used alone or in combination of two or more.

  Of these, butyl cellosolve, isobutyl cellosolve, butyl carbitol, and polyoxyethylene (3 mol) methyl ether are preferable, which can improve the solubility of compound C in water, and improve foaming properties and product stability. It is valid.

  As a compounding quantity, 0-600 parts are preferable with respect to a total of 100 parts of compound A, compound B, and compound C, Most preferably, it is 10-400 parts.

  As the fatty acid (salt), a linear or branched, saturated or unsaturated, natural or synthetic fatty acid (salt) having 8 to 18 carbon atoms can be used.

  Examples of fatty acids (salts) include caprylic acid (salt), capric acid (salt), lauric acid (salt), myristic acid (salt), palmitic acid (salt), stearic acid (salt), oleic acid (salt) Linoleic acid (salt), linolenic acid (salt), palmitoleic acid (salt), myristoleic acid (salt), linolenic acid (salt), and the like.

  As the (salt) in the above, alkali metal salts (lithium, sodium, potassium, etc.), ammonium (ammonia, methylamine, dimethylamine, ethylamine, diethylamine, monoethanolamine, N-methylmonoethanolamine, diethanolamine, triethanolamine) And the like). These may be used alone or in combination of two or more.

  Among these, capric acid (salt), lauric acid (salt), myristic acid (salt), palmitic acid (salt), and stearic acid (salt) are preferable, and are effective for improving the stability of bubbles.

  As a compounding quantity, 0-50 parts are preferable with respect to 100 parts of total amounts of the compound A, the compound B, and the compound C, Most preferably, it is 0.1-30 parts.

  Examples of the water-soluble polymer include cellulose derivatives (such as methyl cellulose and hydroxyethyl cellulose), polyvinyl alcohol, polyvinyl pyrrolidone, sodium alginate, and xanthan gum.

  As a compounding quantity of water-soluble polymer, 0-40 parts are preferable with respect to a total of 100 parts of compound A, compound B, and compound C, Most preferably, it is 0.1-20 parts.

  Examples of water reducing agents include lignin sulfonate, naphthalene sulfonic acid formalin condensate salt, melamine formalin formalin condensate salt, polycarboxylic acid salt, amino sulfonic acid formalin condensate salt, polyoxyalkylene group-containing polycarboxylic acid salt, etc. Can be mentioned.

  As a compounding quantity of a water reducing agent, 0-80 parts are preferable with respect to a total of 100 parts of the compound A, the compound B, and the compound C, Most preferably, it is 1-40 parts.

  The foaming agent for a cement composition of the present invention is used by blending in a cement blend such as cement milk, mortar, concrete, etc., and the cement blend to be used is usually concrete or mortar, Cement milk is formed using cement, water, and the like, and cement milk is formed using cement, water, and the like.

  Conventionally known various cements are used as the cement, and are not particularly limited. For example, ordinary portland cement, moderately heated portland cement, early strong portland cement, alumina cement, blast furnace slag cement, fly ash cement Etc.

  The aggregate is not particularly limited, and various conventionally known aggregates are used. Examples thereof include masa soil, sand, gravel, and lightweight aggregate.

  The fly ash used in the fly ash mortar is not particularly limited, and examples thereof include fly ash types I to IV in JIS A6201-1999 as concrete fly ash.

   As the water, normal tap water, hard water containing a large amount of calcium and magnesium, seawater and the like are used.

   Furthermore, in addition to the above-mentioned components, powders such as lime, silica fume, gypsum and blast furnace slag, and commonly used admixtures are appropriately blended with the cement blend as necessary. For example, a cement dispersant, a setting time adjusting agent, a waterproofing agent, a rust preventive agent, a shrinkage reducing agent and the like are used.

  When producing a cement composition containing bubbles using the foaming agent for a cement composition of the present invention, the method is not particularly limited, and examples thereof include the following methods. In other words, a preform method in which an aqueous solution in which a foaming agent is dissolved is used to produce air bubbles through a foaming apparatus and a cement compound is mixed with the foam, and a foaming agent and other materials are simultaneously introduced into a mixer. A mixed foam method of mixing while foaming is usually used.

  The amount of the foaming agent for a cement composition of the present invention is appropriately set according to the purpose and environment, but is usually set in a range of 0.01 to 10 parts pure with respect to water. .

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

[Preparation of foaming agent for cement composition]
Each compound AD shown to the following Tables 1-4 was mix | blended in the ratio shown to Table 5 and 6, and it mixed, and prepared the foaming agent for cement compositions. As organic solvents (* 3 in Tables 5 and 6), foaming agents (Examples) a to f and foaming agents (Comparative Examples) q and r are butyl carbitol, foaming agents (Example) g ˜l and foaming agent (comparative example) s and t were butyl cellosolve, and foaming agents (examples) m to p were isobutyl cellosolve.

[Examples 1 to 20, Comparative Examples 1 to 6]
<Foamability test>
The above-mentioned various foaming agents were tested for foamability. That is, 100 parts of the foaming agent was dissolved in 2400 parts of water to prepare a foaming agent aqueous solution. Air was introduced into the foaming apparatus at a pressure of 5 kg / cm ^{2 and} an aqueous foaming agent solution was sent to cause foaming, and the foaming ratio was measured. The expansion ratio was obtained by taking bubbles in a 1 L container and measuring the weight. The results are shown in Table 7 below.

<Cement blending test 1>
Using the above various foaming agents, foam mortar was prepared by a preform method, and a foaming agent performance evaluation test was performed. An aqueous solution having a predetermined concentration was prepared at a blending amount of 100 parts of the foaming agent with respect to 2400 parts of water, and bubbles (25 times foaming) were formed using a foaming apparatus. On the other hand, 100 parts of cement, 200 parts of sand and 82 parts of water were mixed with a mortar mixer at low speed for 2 minutes to prepare a mortar. Next, bubbles prepared in advance were put into the mortar, and the mixture was stirred with the mortar mixer for 30 seconds to prepare a bubble mortar.

As water, Examples 1-16 and Comparative Examples 1-4, 7-10 used tap water, and Examples 17-20 and Comparative Examples 5, 6 used seawater. In addition, the blending ratio of the mortar and bubbles was set to about 1/1 by volume ratio (50% air, theoretical specific gravity ^{* 4} = 0.98, * 4: specific gravity of cement, sand, water, and air Calculated from the amount.)

  The specific gravity of the foam mortar thus obtained was measured immediately after production, 30 minutes later, and 60 minutes later. The results are shown in Table 7 below.

[Examples 21 to 39, Comparative Examples 7 to 12]
<Cement blending test 2>
Using the above various foaming agents, bubble fly ash mortar was prepared by a preform method, and a foaming agent performance evaluation test was performed. That is, an aqueous solution having a predetermined concentration was prepared with a blending amount of 100 parts of the foaming agent with respect to 2400 parts of water, and bubbles (25-fold foaming) were formed using a foaming apparatus. On the other hand, 150 parts of cement, 150 parts of fly ash and 350 parts of water were mixed with a mortar mixer at low speed for 2 minutes to prepare mortar. Next, bubbles prepared in advance were put into the mortar, and stirred for 30 seconds with a mortar mixer to prepare bubble fly ash mortar.

As water, Examples 21 to 35 and Comparative Examples 7 to 10 used tap water, and Examples 36 to 39 and Comparative Examples 11 and 12 used seawater. The blending ratio of the mortar and bubbles was set to about 1/1 by volume ratio (50% air, theoretical specific gravity ^{* 5} = 0.69, * 5: cement, fly ash, specific gravity of water, and air Calculated from the amount.)

  The specific gravity of the bubble fly ash mortar thus obtained was measured immediately after production, after 30 minutes, and after 60 minutes. The results are shown in Table 8 below.

  From the foaming test results in Table 7 above, the foaming agents of Examples 1 to 16 were compared with the foaming agents of Comparative Example 3 (using sodium lauryl sulfate) and Comparative Example 4 (using (polyoxyethylene) alkyl sulfate ester salt). It can be seen that high foamability can be obtained. Further, in the cement blending test 1, the specific gravity immediately after the production of the cement slurry is almost the same as the theoretical specific gravity, and there is almost no change in the specific gravity even after one hour has passed, so that stable bubbles are maintained even in the cement slurry. I understand that.

  On the other hand, Comparative Examples 1 and 2 were tested using compounds B and C excluding Compound A as foaming agents. As a result, the specific gravity immediately after the cement slurry was prepared was larger than the theoretical specific gravity. Since the specific gravity after the passage of time is further increased, it can be seen that the bubbles disappeared in the cement slurry. From this, it can be seen that the required performance cannot be obtained with only the compounds B and C excluding the compound A.

  Also in cement blending test 2 (fly ash cement blending test) in Table 8 above, specific gravity immediately after production of Examples 21 to 35 cement slurries was almost the same as the theoretical specific gravity, and the change in specific gravity was almost unchanged even after 1 hour. From this, it can be seen that stable bubbles are retained in the cement slurry.

  On the other hand, in Comparative Examples 7 to 12, the specific gravity immediately after the preparation of the cement slurry is larger than the theoretical specific gravity, and the specific gravity after 1 hour has further increased, so it can be seen that the bubbles disappeared in the cement slurry. .

  Moreover, in Examples 17-20, 36-39, and Comparative Examples 5, 6, 11, and 12, tests using seawater are performed. However, Examples are compared with Comparative Examples when using tap water. Similarly, it can be seen that it exhibits high foamability and excellent foam stability in cement slurry.

  As described above, the foaming agent for concrete of the present invention is represented by the compound A represented by the general formula (1), the compound B represented by the general formula (2), and the general formula (3). By containing the three components of Compound C as essential components, it has high foaming properties and exhibits excellent performance in foamed fly ash mortar as well as foamed cement milk, foamed mortar, and foamed concrete. Will be able to.

  In particular, by setting the mixing ratio of the compound A, the compound B and the compound C to a specific ratio in a pure weight ratio, sufficient foaming properties can be obtained, and even more excellent bubble stability can be obtained. Be able to.

Claims (3)

A foaming agent for a cement composition comprising a compound A represented by the following general formula (1), a compound B represented by the general formula (2), and a compound C represented by the general formula (3).

However, in the formula ^{(1), R 1, Y} , X, X' , and m are as follows.
R ¹ : alkyl group having 8 to 30 carbon atoms, alkenyl group or alkylphenyl group Y: hydrogen or methyl group X, X ′: hydrogen atom, metal atom, or ammonium m: integer of 0 to 5

However, in formula (2), ^{R 2} is a residue obtained by removing carboxyl group from a few 6-20 fatty atoms.

However, in Formula (3), R < ³ >, Y and n are as follows.
R ³ : hydrocarbon group having 8 to 20 carbon atoms Y: hydrogen or methyl group n: integer of 0 to 5   The mixing ratio of compound A and compound B is a pure weight ratio of compound A / compound B = 90/10 to 10/90, and the mixing ratio of compound C to compound A and compound B is the pure weight. The foaming agent for cement composition according to claim 1, wherein the ratio is (compound A + compound B) / compound C = 95/5 to 30/70.   The foaming agent for a cement composition according to claim 1 or 2, which is used for a cement composition containing fly ash.