WO2019229889A1

WO2019229889A1 - Antifoaming agent for hydraulic composition, additive for hydraulic composition, and hydraulic composition

Info

Publication number: WO2019229889A1
Application number: PCT/JP2018/020818
Authority: WO
Inventors: 内藤　裕樹; 章宏古田; 洸平中嶋; 陽澤田; 岡田　和寿
Original assignee: 竹本油脂株式会社
Priority date: 2018-05-30
Filing date: 2018-05-30
Publication date: 2019-12-05
Also published as: CN112203998A; TWI779048B; JPWO2019229889A1; KR102548395B1; TW202003772A; JP7060893B2; KR20210013719A

Abstract

An antifoaming agent for hydraulic compositions which is a polyoxyalkylene-based compound represented by general formula (1), the compound satisfying a first requirement, which is 0.02≤n/(n+m)<0.16, and a second requirement, which is 6≤(n+m)≤100. General formula (1): RO-[(EO)n/(AO)m]-H (wherein R represents a C_8-30 alkyl or alkenyl group and has a linear or branched structure; EO represents an oxyethylene group; AO represents a C_3-18 oxyalkylene group; n and m, each indicating the average number of moles added, are 1 or larger each; and [(EO)n/(AO)m] shows that n mole(s) of EO and m mole(s) of AO have been bonded by block addition or random addition.)

Description

Antifoaming agent for hydraulic composition, additive for hydraulic composition, and hydraulic composition

The present invention relates to an antifoaming agent for a hydraulic composition, an additive for a hydraulic composition, and a hydraulic composition, and more particularly, an antifoaming agent for a hydraulic composition that exhibits high defoaming performance at low temperatures. The hydraulic composition additive containing the antifoaming agent for hydraulic compositions and the hydraulic composition containing the antifoaming agent for hydraulic compositions.

Conventionally, a hydraulic composition is obtained by kneading a hydraulic binder and various materials such as water, filling the mold and curing it, and then demolding the mold to obtain a cured body. In particular, a concrete composition which is a kind of hydraulic composition is mixed and kneaded with various materials such as cement, water, aggregate, and a dispersant, and then poured into a pre-prepared formwork, and placed. It is manufactured by curing for a predetermined time. Such a concrete composition has properties such as strength and durability, and is widely used in various buildings and building structures by utilizing the properties.

Here, an additive (additive for hydraulic composition) may be generally added to the concrete composition in order to improve air entrainment and fluidity when kneading various materials. By using such an additive, good dispersibility can be maintained even when the water content of the concrete composition is reduced. In addition, handling properties (workability) at the time of kneading and construction can be improved. Accordingly, it is possible to construct a concrete composition or the like that is superior in durability, strength, etc., and has excellent temporal stability and workability.

In particular, among the additives for hydraulic compositions added to hydraulic compositions, in recent years, polycarboxylic acids have been developed as dispersants that enhance the dispersibility of various materials of hydraulic compositions and can be uniformly mixed and kneaded. It is known to use a system dispersant. By using a polycarboxylic acid-based dispersant, the water-reducing property of the hydraulic composition can be increased. On the other hand, by using a polycarboxylic acid-based dispersant, air entrainment can be improved, but the bubble diameter of bubbles generated during kneading is increased, which may affect construction work. In order to eliminate such problems, so-called AE agents (Air Entraining agents) are used in combination in order to generate fine and high-quality bubbles and improve freeze-dissolution.

At this time, when the polycarboxylic acid-based dispersant and the AE agent are used in combination, an antifoaming agent (an antifoaming agent for a hydraulic composition) is generally used for the purpose of eliminating many bubbles generated by the AE agent or the like. Sometimes. For example, a concrete composition containing a polyoxyalkylene compound, cement, water, fine aggregate and coarse aggregate as essential components is known (see Patent Document 1). In the concrete composition, the polyoxyalkylene compound is expressed as “0.15 <u, where u is the total number of added moles of oxyethylene groups in the oxyalkylene group and v is the total number of added moles of oxyalkylene groups having 3 or more carbon atoms. /(U+v)<0.9 ”and having at least one aliphatic hydrocarbon group in which 5 or more carbon atoms are continuous in the molecule. Thereby, it is advantageous to suppress an increase in the amount of air accompanying the extension of the kneading time and keep the air entrainment amount stable. As a result, it is possible to provide a high-quality concrete composition excellent in durability and strength.

That is, in the past, it was thought that a defoaming agent in a concrete composition should have a high hydrophobicity, but by improving the hydrophilicity of the polyoxyalkylene compound by the oxyethylene group, air by an AE agent or the like is used. Generation | occurrence | production of a bubble can be suppressed effectively and the increase in the air quantity accompanying the kneading | mixing time extension can be suppressed. As a result, there is no increase in the amount of air, and the amount of air entrainment can be stabilized.

JP 2003-226565 A

On the other hand, in the case of a general polyoxyalkylene compound disclosed in the above-mentioned Patent Document 1 or the like, there is a possibility of causing the following problems. Specifically, the polyoxyalkylene compound used as the antifoaming agent for the hydraulic composition is less effective in the antifoaming agent and further disappears in the hydraulic composition at low temperatures. There was a problem. That is, there is a problem that the amount of antifoam added increases at low temperatures, and even if the amount of antifoam added is increased, air bubbles cannot be suppressed. In this case, the cost of the hydraulic composition increases with an increase in the amount of antifoaming agent added, and further, it is impossible to suppress air bubbles, and a hydraulic composition excellent in durability and strength can be obtained. It was sometimes difficult.

In the case of the polyoxyalkylene compound disclosed in Patent Document 1, the generation of air bubbles caused by the AE agent or the like could be effectively suppressed. However, the polyoxyalkylene compound sometimes fails to exhibit sufficient defoaming performance at low temperatures. In particular, when the temperature after kneading is less than 10 ° C., the defoaming performance is drastically lowered, and it is difficult to suppress air bubbles even when the amount of the defoaming agent is increased, and the durability and strength are excellent. It may be difficult to obtain a hydraulic composition.

As a result of intensive studies to solve the above problems, the applicant of the present application has determined that oxyethylene constituting the polyoxyalkylene compound in the polyoxyalkylene compound used as an antifoaming agent for the hydraulic composition. By optimizing the molar ratio of the group and the total number of moles added of the oxyethylene group constituting the polyoxyalkylene compound and the oxyethylene group having 3 to 18 carbon atoms, high defoaming performance is exhibited at low temperatures. Invention related to hydraulic composition including antifoaming agent for hydraulic composition, additive for hydraulic composition containing antifoaming agent for hydraulic composition, and antifoaming agent for hydraulic composition, etc. I found.

Therefore, in view of the above circumstances, the present invention has an object to provide an antifoaming agent for a hydraulic composition, an additive for a hydraulic composition, and a hydraulic composition capable of exhibiting particularly high antifoaming performance at low temperatures. To do.

According to the present invention, the following antifoaming agent for hydraulic composition, additive for hydraulic composition, and hydraulic composition are provided.

[1] A polyoxyalkylene compound represented by the following general formula (1):
First condition: 0.02 ≦ n / (n + m) <0.16, and
Second condition: An antifoaming agent for a hydraulic composition that satisfies the relationship of 6 ≦ n + m ≦ 100.
RO-[(EO) n / (AO) m] -H (1)
(However, R represents an alkyl group or alkenyl group having 8 to 30 carbon atoms, and has a linear or branched structure. EO represents an oxyethylene group, and AO represents 3 carbon atoms. Represents an oxyalkylene group of ˜18, n and m each represent an average addition mole number, n is 1 or more, m is 1 or more, and [(EO) n / (AO) m] is , N mol EO and m mol AO indicate block addition or random addition.)

[2] The antifoaming agent for a hydraulic composition according to [1], which can be used in a range where the kneading temperature, which is a temperature immediately after kneading the hydraulic composition, is 3 ° C. or more and less than 15 ° C.

[3] The antifoaming agent for a hydraulic composition according to [1] or [2], wherein R in the general formula (1) is an alkyl group or alkenyl group having 14 to 22 carbon atoms.

[4] The antifoaming agent for a hydraulic composition according to any one of [1] to [3], wherein AO in the general formula (1) is an oxypropylene group.

[5] The antifoaming agent for a hydraulic composition according to any one of [1] to [4], wherein the second condition further satisfies a condition of 6 ≦ n + m ≦ 50.

[6] An additive for a hydraulic composition comprising the antifoaming agent for a hydraulic composition according to any one of [1] to [5], a polycarboxylic acid-based dispersant, and water as essential components.

[7] A hydraulic composition comprising the antifoaming agent for a hydraulic composition according to any one of [1] to [5], a polycarboxylic acid-based dispersant, and cement as essential components.

[8] A bone containing the antifoaming agent for a hydraulic composition according to any one of [1] to [5], a polycarboxylic acid-based dispersant, cement, fine bone and / or coarse aggregate. A hydraulic composition comprising a material as an essential component.

According to the antifoaming agent for a hydraulic composition of the present invention, a high defoaming performance is exhibited at a low temperature, and the difference between a normal temperature and a low temperature can be reduced. Furthermore, creating a hydraulic composition excellent in durability and strength by using the antifoaming agent for hydraulic composition or the additive for hydraulic composition containing the antifoaming agent for hydraulic composition. Can do.

Hereinafter, embodiments of the antifoaming agent for hydraulic composition, the additive for hydraulic composition, and the hydraulic composition of the present invention will be described. Here, the antifoaming agent for hydraulic composition of the present invention (hereinafter simply referred to as “antifoaming agent”), the additive for hydraulic composition, and the hydraulic composition are limited to the following embodiments. However, changes, modifications, improvements and the like can be added without departing from the scope of the present invention.

1. Antifoaming agent (antifoaming agent for hydraulic composition)
The antifoaming agent of one embodiment of the present invention is a polyoxyalkylene compound represented by the following general formula (1):
First condition: 0.02 ≦ n / (n + m) <0.16, and
Second condition: 6 ≦ n + m ≦ 100
It satisfies the relationship.
RO-[(EO) n / (AO) m] -H (1)

In the above general formula (1), “R” represents an alkyl group or alkenyl group having 8 to 30 carbon atoms, and exhibits a linear or branched structure. “EO” represents an oxyethylene group, and “AO” represents an oxyalkylene group having 3 to 18 carbon atoms. On the other hand, n and m each represent an average added mole number, n is 1 or more, and m is 1 or more. Furthermore, [(EO) n / (AO) m] indicates that n moles of EO and mmoles of AO are added in blocks or randomly.

That is, the antifoaming agent of this embodiment is a polyoxyalkylene compound represented by the above general formula (1), and an oxyethylene group (EO) and an oxyalkylene group (AO) are added in blocks or randomly. The average added mole number of EO and AO satisfies both the first condition and the second condition shown above.

Furthermore, the antifoaming agent of the present embodiment has a “kneading temperature” that is a temperature immediately after kneading the hydraulic composition of 0 ° C. or more and less than 18 ° C., more preferably 3 ° C. or more and less than 15 ° C. Can be used in a range. That is, it has excellent defoaming performance at low temperatures. Here, in this specification, “low temperature (hour)” is defined as a range of 0 ° C. or more and less than 18 ° C.

Here, R in the general formula (1) is an alkyl or alkenyl group having 8 to 30 carbon atoms, more preferably 14 to 22 carbon atoms. In particular, R may be a residue obtained by removing a hydroxy group from an alcohol, and usable alcohols are not particularly limited. For example, octanol, nonaol, decanol, undecanol, dodecanol, tridecanol, tetradecanol are usable. Nord, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, heneicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, heptacosanol, octacosanol, nonacosanol and triacon Linear alkanols such as butanol; 2-ethylhexanol, 2-propylheptanol, 2-butyloctanol, 1-methylheptadecanol, 2-hexyloctanol, 2 Branched alkanols such as hexyldecanol, isodecanol, isotridecanol, 3,5,5-trimethylhexanol; octenol, nonenol, decenol, undecenol, dodecenol, tridecenol, tetradecenol, pentadecenol, hexadecenol, pentadecenol, hexadecenol, heptadecenol, Linear alkenols such as octadecenol, nonadecenol, eisenol, docosenol, tetracosenol, pentacosenol, hexacosenol, heptacosenol, octacosenol, nonacosenol and triaconsenol; 2-ethylhexenol, 1-methylheptadecenol, isotridecenol and Examples include branched alkenols such as isooctadecenol. Furthermore, as alcohol used as R, you may use only 1 type from the said enumeration, or may use 2 or more types of alcohol together.

Specific examples of alcohols that can be used include higher-grade alcohols derived from natural fats and oils, the Calcoal series (Kao), the Conol series (New Nippon Rika), the Fine Oxocol series (Nissan Chemical Industries), the Neodol series ( Shell Chemicals), SAFOL series (SASOL), EXXAL series (Exxon Mobile) and the like.

On the other hand, AO (oxyalkylene group) in the general formula (1) represents an oxyalkylene group having 3 to 18 carbon atoms. Examples of the oxyalkylene group having 3 to 18 carbon atoms include oxypropylene group, oxybutylene group, oxyhexylene group, oxyoctylene group, and oxystyrene group. In particular, AO is preferably an oxypropylene group. Thereby, higher defoaming performance can be exhibited at low temperatures.

In addition, in the antifoaming agent of this embodiment, the second condition in the general formula (1) may satisfy the condition of 6 ≦ n + m ≦ 50. That is, the range of the second condition described above may be narrower. By further limiting the range of the second condition, an excellent antifoaming agent that exhibits higher defoaming performance at low temperatures can be obtained.

2. Additive for hydraulic composition, and hydraulic composition By using the antifoaming agent shown above, the additive for hydraulic composition and the hydraulic composition can be obtained. Here, the additive for hydraulic compositions contains a polycarboxylic acid-based dispersant and water as essential components together with the antifoaming agent. Thereby, the additive for hydraulic compositions which can exhibit high defoaming performance also at the time of low temperature can be obtained. On the other hand, the hydraulic composition further includes cement as an essential component in the hydraulic composition additive, or further includes cement and aggregate as essential components. In addition, since the water contained in the additive for hydraulic compositions or the hydraulic composition is well-known, detailed description is abbreviate | omitted here. Furthermore, as the aggregate contained in the hydraulic composition, fine aggregates such as sand and / or coarse aggregates such as gravel, crushed stone, granulated slag, recycled aggregate, and the like can be used as appropriate. The details of the polycarboxylic acid-based dispersant will be described later, and thus the description thereof is omitted here.

3. Production method of antifoaming agent (polyoxyalkylene compound) The production method for producing the antifoaming agent (polyoxyalkylene compound) of the present embodiment is not particularly limited, and is produced by a known production method. be able to. For example, a polyoxyalkylene compound can be obtained by adding an alkylene oxide to an alcohol. Here, when adding an alkylene oxide, a catalyst can be used. Examples of the catalyst include alkali catalysts such as alkali metals and alkaline earth metals, their hydroxides, alcoholates, Lewis acid catalysts, and composite metals. A catalyst can be used, and an alkali catalyst can be preferably used.

Usable alkali catalysts include, for example, sodium, potassium, sodium potassium amalgam, sodium hydroxide, potassium hydroxide, sodium hydride, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, potassium butoxide and the like. Preferred are sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, potassium butoxide.

On the other hand, usable Lewis acid catalysts include, for example, tin tetrachloride, boron trifluoride, boron trifluoride diethyl ether complex, boron trifluoride di-n-butyl ether complex, boron trifluoride tetrahydrofuran complex, and trifluoride. Examples thereof include boron trifluoride compounds such as boron phenol complex and boron trifluoride acetic acid complex.

These catalysts can be neutralized and removed after the addition reaction, but may be left as they are. When neutralizing a catalyst, it can be performed by a well-known method. For example, when the catalyst is an alkaline catalyst, the neutralizing agent includes hydrochloric acid, sulfuric acid, methanesulfonic acid, phosphoric acid, acetic acid, lactic acid, citric acid, succinic acid and other acids, silicates such as aluminum silicate and magnesium silicate, activated clay Adsorbents such as acidic clay, silica gel, and acidic ion exchange resin can be used.

Further, the neutralization will be specifically described. Examples of commercially available adsorbents include KYOWARD 600 and 700 (trade names: Kyowa Chemical Industry, respectively), Mizuka Life P-1, P-1S, P-1G, F Silicates such as -1G (each trade name: Mizusawa Chemical Industry), Tomita-AD600, 700 (each trade name: Tomita Pharmaceutical), Diaion (trade name: Mitsubishi Chemical), Amberlist, Amberlite, Dowex (each An ion exchange resin such as a trade name: Dow Chemical) can be used. These neutralizing agents may be used alone or in combination of two or more.

The neutralized salt (neutralized product) generated by neutralization of the catalyst can be further solid-liquid separated. As a method for solid-liquid separation of the neutralized salt, for example, a known technique such as filtration or centrifugation can be used. Here, solid-liquid separation by filtration is performed under reduced pressure or pressure using, for example, a filter paper, a filter cloth, a cartridge filter, a two-layer filter of cellulose and polyester, a metal mesh filter, a metal sintered filter, and the like. The reaction can be carried out at 20 to 140 ° C. On the other hand, solid-liquid separation by centrifugation can be carried out using a centrifugal separator such as a decanter or a centrifugal clarifier. If necessary, about 1 to 30 parts by mass of water can be added to 100 parts by mass of the solution before solid-liquid separation. As the solid-liquid separation, particularly when filtration is performed, it is more preferable to use a filter aid because the filtration rate is improved.

The filter aid used for the filtration is not particularly limited. For example, each series of Celite, High Flow Supercell, and Cell Pure (trade names: Advanced Minalals Corporation), silica # 645, silica # 600H, silica # Diatomite such as 600S, Silica # 300S, Silica # 100F (Product name: Central Silica), Dicalite (Product name: Grefco), LocaHelp (Product name: Mitsui Mining), Topco (Product name: Showa Chemical), etc. Perlite; Cellulose-based filter aids such as KC Flock (trade name: Nippon Paper Industries) and Fibracel (Advanced Minerals Corporation); and silica gels such as silopute (trade name: Fuji Silysia Chemical). Further, only one type of the above-mentioned filter aid may be used, or two or more types may be used in combination.

Furthermore, known polycarboxylic acid dispersants can be used. For example, a copolymer comprising a monomer represented by the following general formula (2) and an unsaturated carboxylic acid monomer can be mentioned.

R ¹ —O—A—R ² (2)
(In the general formula (2), R ¹ represents an alkenyl group having 2 to 5 carbon atoms, or an unsaturated acyl group having 3 or 4 carbon atoms, and A represents 1 of an oxyalkylene group having 2 to 4 carbon atoms. (Poly) oxyalkylene units having an average addition mole number of 1 to 500 composed of seeds or two or more kinds, and R ² is a hydrogen atom, an alkyl group having 1 to 22 carbon atoms or a fat having 1 to 22 carbon atoms Represents an acyl group.)

As unsaturated carboxylic acid monomers, monocarboxylic acid monomers such as (meth) acrylic acid, crotonic acid and their salts, and dicarboxylic acid monomers such as maleic acid, itaconic acid, fumaric acid, etc. And its salts. Of these, (meth) acrylic acid, maleic acid and salts thereof are preferred. The salt is not particularly limited, and examples thereof include alkali metal salts such as sodium and potassium, alkaline earth metal salts such as magnesium and calcium, metal salts with aluminum and iron, ammonium salts, and amine salts.

The copolymer may be obtained by reacting any appropriate monomer (third monomer) in addition to the above-mentioned monomer and unsaturated carboxylic acid monomer. good. In this case, for example, (meth) allylsulfonic acid and its salt, (meth) acrylamide, acrylonitrile, (meth) acrylic acid ester and the like can be used as the third monomer.

Furthermore, the polycarboxylic acid-based dispersant can be produced by a known method. The copolymer can be produced by a known method. For example, the copolymer is synthesized by radical polymerization, and the above monomer, unsaturated carboxylic acid monomer, and third monomer are mixed (heated) with a radical initiator. can get. Examples of the radical initiator used include persulfates such as potassium persulfate and ammonium persulfate, hydrogen peroxide, 2,2-azobis (2-amidinopropane) dihydrochloride, azobisisobutyronitrile and the like. These can also be used as a redox initiator in combination with a reducing substance such as sulfite or L-ascorbic acid, or an amine. In order to bring the mass average molecular weight of the resulting copolymer into a desired range, a chain transfer agent such as 2-mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thioglycolic acid, mercaptoethanol, thioglycerin and the like is used. It can also be used. In the polymerization, water or an organic solvent may be used as a solvent, or no solvent may be used.

Hereinafter, the antifoaming agent of the present invention and the hydraulic composition containing the antifoaming agent will be described based on the following examples. In addition, the antifoamer and hydraulic composition of this invention are not limited to the following Example. In addition, since it already demonstrated about the conditions of the specific method (addition reaction etc.) for manufacturing an antifoamer, detailed description is abbreviate | omitted here.

1. Synthesis of Antifoaming Agent (Polyoxyalkylene Compound) First, an alcohol was used as R in the general formula (1) to synthesize an antifoaming agent (polyoxyalkylene compound). First, 128.3 g of alcohol A1 (“Angekor 85AN (trade name: Shin Nippon Rika)”) and 0.9 g of potassium hydroxide were put into a pressure vessel equipped with a stirrer, a pressure gauge, and a thermometer. The melting point of alcohol A1 (“Angekor 85AN”) is about 11 ° C., and it is in a liquid state at room temperature around 20 ° C.

In this state, after dehydration treatment, 87.1 g of ethylene oxide was injected at a gauge pressure of 0.4 MPa over 1 hour while maintaining the reaction system in the pressure vessel at 110 ± 5 ° C., and then for 2 hours. Aged. Further, while maintaining the above reaction system at 135 ± 5 ° C., 706.5 g of propylene oxide was injected at a gauge pressure of 0.4 MPa over 5 hours, and then aged for 2 hours to complete the reaction.

Thereafter, neutralization treatment was performed using “KYOWARD 600 (trade name: Kyowa Chemical Industry)” as an adsorbent, followed by filtration and purification to obtain a purified product. From the analysis results of NMR and gel permeation chromatography (mass average molecular weight in terms of polystyrene), the purified product was added with 4.1 mol of ethylene oxide and 2.2 mol of propylene oxide in order to 1.0 mol of lauryl alcohol. Antifoaming agent af-1 (polyoxyalkylene compound). The measurement conditions of NMR and gel permeation chromatography are shown below.
<Measurement conditions>
(1) NMR
Apparatus: Varian Mercury 300 (300 MHz)
Nuclide: 1H, 13C
Solvent: CDCl3

(2) Gel permeation chromatography device: HLC-8120GPC (Tosoh)
Column: TSK gel Super H4000 + TSK gel Super H3000 + TSK gel Super H2000 (Tosoh)
Detector: Differential refractometer (RI)
Eluent: Tetrahydrofuran Flow rate: 0.5 mL / min Column temperature: 40 ° C
Sample concentration: Eluent solution standard material with sample concentration of 0.5 mass%: Polystyrene (Tosoh)

By changing the types of alcohols A1 to A4 used, alkylene oxide (oxypropylene group), addition order in addition reaction, addition amount, etc., the antifoaming agent af-1 was changed according to the conditions shown in Table 1 below. The same treatment as in the synthesis was performed to synthesize various antifoaming agents af-2 to af-6, af-e1, and af-e2. Table 2 below summarizes the detailed characteristics and properties (linear / branched, saturated / unsaturated, and carbon number, etc.) of alcohols A1 to A4 used in the synthesis of the antifoaming agent. .

In Table 1 above, the antifoaming agents af-1 to af-6 and the first and second conditions in the antifoaming agent of the present invention were both satisfied. On the other hand, antifoaming agents af-e1 and af-e2 are synthesized deviating from the first condition.

2. Synthesis of copolymer used for polycarboxylic acid-based dispersant and production of dispersant (1) Production Example 1 (Production of Dispersant SP-1)
140.1 g of ion-exchanged water, 163.0 g of α-methacryloyl-ω-methoxy-poly (n = 9) oxyethylene, 28.8 g of methacrylic acid, 3.8 g of 3-mercaptopropionic acid, 30% aqueous sodium hydroxide solution 9. 9 g was charged into a reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, and a nitrogen introduction tube, dissolved uniformly while stirring, and then the atmosphere was replaced with nitrogen, and the temperature of the reaction system was adjusted to 60 ° C. in a hot water bath. . Next, 63.9 g of a 3.0% aqueous sodium persulfate solution was added to initiate the polymerization reaction. Two hours later, 28.8 g of 3.0% aqueous sodium persulfate solution was added and maintained at 60 ° C. for 2 hours to complete the polymerization reaction. Then, 30% aqueous sodium hydroxide solution was added to adjust the pH to 8, and the dispersant adjusted to 20% with ion-exchanged water was designated as (SP-1).

(2) Production Example 2 (Production of Dispersant SP-2)
209.2 g of ion-exchanged water, 181.9 g of α-methacryloyl-ω-methoxy-poly (n = 45) oxyethylene, 15.8 g of methacrylic acid, 2.0 g of 3-mercaptopropionic acid, thermometer, stirrer, dropping funnel The mixture was charged into a reaction vessel equipped with a nitrogen introduction tube and dissolved uniformly with stirring, the atmosphere was replaced with nitrogen, and the temperature of the reaction system was adjusted to 60 ° C. in a warm water bath. Next, 27.7 g of a 1.0% aqueous hydrogen peroxide solution was added dropwise over 2.5 hours. Thereafter, 7.1 g of a 1.0% aqueous hydrogen peroxide solution was added dropwise over 3.5 hours to complete the polymerization reaction. Thereafter, 30% aqueous sodium hydroxide solution was added to adjust the pH to 9, and the dispersant adjusted to a concentration of 20% with ion-exchanged water was designated as (SP-2).

(3) Production Example 3 (Production of Dispersant SP-3)
Charge 82.6 g of ion-exchanged water and 175.7 g of α-methallyl-ω-hydroxy-poly (n = 113) oxyethylene into a reaction vessel equipped with a thermometer, stirrer, dropping funnel and nitrogen introducing tube while stirring. After uniformly dissolving, the atmosphere was replaced with nitrogen, and the temperature of the reaction system was set to 60 ° C. in a warm water bath. Next, 9.8 g of 10.0% hydrogen peroxide aqueous solution was dropped over 3.0 hours, and at the same time, an aqueous solution in which 11.7 g of acrylic acid and 7.8 g of hydroxyethyl acrylate were dissolved in 97.6 g of ion-exchanged water. The solution was added dropwise over 3.0 hours, and at the same time, an aqueous solution prepared by dissolving 0.8 g of 3-mercaptopropionic acid and 1.0 g of ascorbic acid in 7.0 g of ion exchange was added dropwise over 4.0 hours. Thereafter, the temperature was maintained at 60 ° C. for 0.5 hours to complete the polymerization reaction. Then, 30% aqueous sodium hydroxide solution was added to adjust the pH to 5, and the dispersant adjusted to a concentration of 20% with ion-exchanged water was designated as (SP-3).

The mass average molecular weight of the dispersant was measured by gel permeation chromatography according to the measurement conditions shown below.
<Measurement conditions>
Equipment: Shodex GPC-101 (Showa Denko)
Column: OHpak SB-806M HQ + SB-806M HQ (Showa Denko)
Detector: Differential refractometer (RI)
Eluent: 50 mM aqueous sodium nitrate flow rate: 0.7 mL / min Column temperature: 40 ° C.
Sample concentration: Eluent solution with sample concentration of 0.5% by mass Standard substances: Polyethylene glycol, polyethylene oxide (Agilent)

Water was removed from the dispersants SP-1 to SP-3 produced in each of Production Examples 1 to 3, and the solution was adjusted to a concentration of 5% using heavy water, and measured by 300 MHz NMR. It was. Thereby, it was confirmed that each monomer was polymerized and became a copolymer. Types of each component (component A, component B (component B1, component B2)) used in each of the dispersants SP-1 to SP-3 produced in Production Examples 1 to 5, their respective masses (%), and The mass average molecular weights and pH values of the dispersants SP-1 to SP-3 measured as described above are shown in Table 3 below.

In the description in Table 3 above, the following terms have the following meanings.
L-1: α-methacryloyl-ω-methoxy-poly (n = 9) oxyethylene L-2: α-methacryloyl-ω-methoxy-poly (n = 45) oxyethylene L-3: α-methallyl-ω- Hydroxy-poly (n = 113) oxyethylene L-4: Hydroxyethyl acrylate M-1: Methacrylic acid M-2: Acrylic acid

3. Next, the effect of the defoaming performance of the various antifoaming agents af-1 and the like (polyoxyalkylene compounds) synthesized was confirmed. First, a concrete composition was prepared as shown below.

(1) Preparation of concrete composition Each material used what adjusted temperature so that it might become the target kneading temperature. 55L forced biaxial mixer and ordinary Portland cement (Pacific Cement, Ube Mitsubishi Cement, Sumitomo Osaka Cement. Equal mixing of the above three brands, specific gravity = 3.16), and fine aggregate ( Oikawa water sand, specific gravity = 2.58) and coarse aggregate (Okazaki crushed stone, specific gravity = 2.66) were sequentially added at the blending ratios shown in Table 4, and after 10 seconds of air kneading, slump The polycarboxylic acid dispersants SP-1 and SP-2 shown in Table 3 and “AE-300 (trade name: Takemoto Yushi)” as the AE agent are applied to the cement so as to be 18 ± 2.5 cm. 0.0025% by mass, the antifoaming agents af-1 to af-6, af-e1, af-e2 shown in Table 1 are of the types shown in Table 6 below, adjusted in addition amount and mixed with water The mixture was added and kneaded for 90 seconds. Here, the antifoaming agent af-1 and the like and the polycarboxylic acid dispersant SP-1 and the like are regarded as a part of the kneaded water. Similarly, the polycarboxylic acid-based dispersant SP-3 shown in Table 3 and the antifoaming agents af-1 to af-6, af-e1, and af-e2 shown in Table 1 at the blending ratios shown in Table 5 are as follows. Kneading was carried out with the types shown in Table 7.

(2) Effect of defoaming performance The “air content (%)” of the concrete composition immediately after mixing was measured in accordance with JIS-A1128. The amount of air (%) indicates the volume% in the hydraulic composition. Further, simultaneously with the measurement of the air amount (%), “slump (cm)” was measured according to JIS-A1101. Furthermore, simultaneously with the measurement of the air amount (%), the temperature immediately after kneading was measured according to JIS-A1156. The effect of the defoaming performance of the antifoaming agent at low temperatures was confirmed by the amount of air (%) and the temperature immediately after kneading. The measurement results are shown in Tables 6 and 7 below.

In order to compare the effect of antifoaming performance, the amount of antifoaming agent added was fixed for each formulation. According to this, the antifoaming agents af-1 to af-6 satisfying the first condition and the second condition in the present invention all have a good defoaming effect when the temperature immediately after kneading is as low as 5 ° C or 12 ° C. It was confirmed that In particular, it was shown that good defoaming performance was exhibited even when the temperature immediately after kneading was lower than 5 ° C. On the other hand, when the antifoaming agents af-e1 and af-e2 synthesized for comparison are used, it is shown that the air amount (%) increases particularly when the mixing temperature is low at 5 ° C. (Comparative Examples 1, 2, 4, 5). When the kneading temperature was 12 ° C., the value of air amount (%) was slightly improved, but in all cases, low defoaming performance was exhibited (Comparative Examples 3 and 6). That is, it was confirmed that the antifoaming agent of the present invention exhibits high antifoaming performance particularly at low temperatures when used as one of the essential components of the hydraulic composition.

The antifoaming agent for a hydraulic composition of the present invention can be used as an antifoaming agent when preparing a hydraulic composition. Furthermore, according to the additive for hydraulic compositions of the present invention, it can be used as an additive when preparing a hydraulic composition. The hydraulic composition of the present invention can be beneficially used in various buildings and building members of building members by using an antifoaming agent that can exhibit high defoaming performance at low temperatures.

Claims

A polyoxyalkylene compound represented by the following general formula (1),
First condition: 0.02 ≦ n / (n + m) <0.16, and
Second condition: 6 ≦ n + m ≦ 100
Antifoaming agent for hydraulic composition satisfying the above relationship.
RO-[(EO) n / (AO) m] -H (1)
(However, R represents an alkyl group or alkenyl group having 8 to 30 carbon atoms, and has a linear or branched structure. EO represents an oxyethylene group, and AO represents 3 carbon atoms. Represents an oxyalkylene group of ˜18, n and m each represent an average addition mole number, n is 1 or more, m is 1 or more, and [(EO) n / (AO) m] is , N mol EO and m mol AO indicate block addition or random addition.)
The antifoaming agent for a hydraulic composition according to claim 1, which can be used in a range in which a kneading temperature, which is a temperature immediately after kneading the hydraulic composition, is 3 ° C or higher and lower than 15 ° C.
R in the general formula (1) is
The antifoaming agent for a hydraulic composition according to claim 1 or 2, which is an alkyl group or an alkenyl group having 14 to 22 carbon atoms.
AO in the general formula (1) is
The antifoaming agent for a hydraulic composition according to any one of claims 1 to 3, which is an oxypropylene group.
The second condition is:
6 ≦ n + m ≦ 50
The antifoaming agent for a hydraulic composition according to any one of claims 1 to 4, further satisfying the following conditions:
An antifoaming agent for a hydraulic composition according to any one of claims 1 to 5;
A polycarboxylic acid dispersant;
An additive for hydraulic compositions containing water as an essential component.
An antifoaming agent for a hydraulic composition according to any one of claims 1 to 5;
A polycarboxylic acid dispersant;
A hydraulic composition containing cement as an essential component.
An antifoaming agent for a hydraulic composition according to any one of claims 1 to 5;
A polycarboxylic acid dispersant;
Cement,
A hydraulic composition comprising a fine aggregate and / or an aggregate containing coarse aggregate as an essential component.