TW202003772A - Antifoaming agent for hydraulic composition, additive for hydraulic composition, and hydraulic composition - Google Patents

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 C8-30 alkyl or alkenyl group and has a linear or branched structure; EO represents an oxyethylene group; AO represents a C3-18 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 hydraulic compositions, additives for hydraulic compositions and hydraulic compositions, and more specifically to an antifoaming agent for hydraulic compositions that can exhibit high defoaming performance at low temperatures An additive for a hydraulic composition containing the antifoaming agent for a hydraulic composition and a hydraulic composition containing the antifoaming agent for the hydraulic composition.

Conventionally, a hydraulic composition is a hardened body obtained by kneading various materials such as a hydraulic binder and water, filling a mold, and hardening the mold. In particular, the concrete composition, which is one of the hydraulic compositions, is mixed and kneaded with various materials such as cement, water, aggregates, and dispersants, and poured into a mold prepared in advance to harden at a predetermined time. To be manufactured. Such a concrete composition has characteristics of excellent strength and durability, and is widely used in various buildings or building structures to fully exert the characteristics.

Here, in order to increase gas transmission characteristics or fluidity when kneading various materials, concrete compositions generally add additives (additives for hydraulic compositions). With the use of additives like this, it is possible to maintain good dispersion characteristics even when the concrete composition has been reduced in water. In addition, the operating characteristics (construction characteristics) during kneading or construction can be made good. Therefore, the durability and strength of the concrete composition can be improved, and it can be built into a concrete composition with excellent stability and operability over time.

Especially in recent years, among additives for hydraulic compositions added to hydraulic compositions, it is known to use a polycarboxylic acid type dispersant as a dispersant, which can improve the dispersion characteristics of various materials of hydraulic compositions. Mix and knead evenly. By using a polycarboxylic acid type dispersant, the water reducing properties of the hydraulic composition can be improved. On the other hand, although the use of a polycarboxylic acid type dispersant provides excellent gas transmission characteristics, the bubbles generated during kneading have a large bubble diameter, which may affect construction work. In order to solve the above problems and generate fine and fine-textured air bubbles to improve the freezing solubility, the so-called AE agent (air entraining agent) is currently used in combination.

In this case, when a polycarboxylic acid type dispersant and an AE agent are used in combination, in general, an antifoaming agent (antifoaming agent for hydraulic composition) is used to eliminate most of the bubbles generated by the AE agent and the like. For example, a concrete composition containing polyoxyalkylene compound, cement, water, fine aggregate, and coarse aggregate as essential components is known (refer to Patent Document 1). In this concrete composition, the polyoxyalkylene compound is when the total number of added moles of oxyethylene groups in the oxyalkylene group is u and the total number of added moles of oxyalkylene groups with a carbon number of 3 or more is v , Satisfying the relationship of "0.15<u/(u+v)<0.9", and having at least one carbon atom with 5 or more continuous aliphatic hydrocarbon groups in the molecule. This can reduce the increase in air volume as the kneading time increases, and has the advantage of stably maintaining the air volume. As a result, a high-quality concrete composition with excellent durability and strength can be provided.

That is, in the conventional technology, it is considered to use a highly hydrophobic material as a defoaming agent for the concrete composition, but the oxyethylene group of the polyoxyalkylene compound improves the hydrophilicity, which can effectively suppress bubbles caused by the AE agent and the like This can suppress the increase in the amount of air as the kneading time increases. As a result, the air volume can be stabilized without increasing the air volume.

【Prior Technical Literature】

Patent Literature

Patent Document 1: Japanese Patent Publication No. 2003-226565

On the other hand, in the case of the general polyoxyalkylene compound disclosed in Patent Document 1, the following problems may occur. Specifically, the polyoxyalkylene compound used as the defoaming agent for the hydraulic composition has a problem that the effect of the defoaming agent in the hydraulic composition at a low temperature is reduced and the defoaming effect disappears. That is, there is a problem that the addition amount of the antifoaming agent increases at a low temperature, and the increase in the amount of the antifoaming agent further increases and the bubble cannot be suppressed. In this case, as the amount of the defoamer added increases, the cost of the hydraulic composition becomes high, and even bubbles cannot be suppressed, and it is difficult to obtain a stable hydraulic composition with excellent durability and strength.

The polyoxyalkylene compound disclosed in the above Patent Document 1 can effectively suppress bubbles generated by the AE agent or the like. However, the polyoxyalkylene compound may fail to exhibit sufficient defoaming performance at low temperatures. In particular, when the temperature after kneading is lower than 10°C, the defoaming efficiency will drop sharply. Even if the amount of the defoaming agent is increased, it is difficult to suppress bubbles, and it is difficult to obtain a hydraulic composition with excellent durability and strength.

In order to solve the above-mentioned problems, the inventors of the present invention have repeatedly studied and found that by optimizing the polyoxyalkylene compound used as the defoaming agent of the hydraulic composition, the oxyethylene group constituting the polyoxyalkylene compound The molar ratio and the total added mole number of the oxyethylene group constituting the polyoxyalkylene compound and the oxyethylene group having 3 to 18 carbon atoms can be used as a defoaming agent for hydraulic compositions that exhibit high defoaming performance at low temperatures, An additive for a hydraulic composition containing the antifoaming agent for a hydraulic composition, and a hydraulic composition prepared by including an antifoaming agent for the hydraulic composition and the like.

The object of the present invention is to provide a defoamer for hydraulic compositions, additives for hydraulic compositions, and hydraulic compositions that can exhibit high defoaming performance at low temperatures in view of the above facts.

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

[1] An antifoaming agent for a hydraulic composition, which is a polyoxyalkylene compound represented by the following general formula (1) and satisfies the following relationship: First condition: 0.02≦n/(n+m)<0.16 ; And the second condition: 6≦n+m≦100; RO-[(EO)n/(AO)m]-H...(1). However, R represents an alkyl or alkenyl group having 8 to 30 carbon atoms and has a linear or branched structure. EO is an oxyethylene group, and AO is an oxyalkylene group having 3 to 18 carbon atoms. n and m represent the average addition mole number, respectively, n is 1 or more, and m is 1 or more. In addition, [(EO)n/(AO)m] means that n moles of EO and m moles of AO are added or randomly added.

[2] The defoamer for hydraulic compositions described in [1] can be used in a range where the kneading temperature immediately after kneading of the hydraulic composition is 3°C or more and less than 15°C.

[3] The defoamer for hydraulic compositions described in [1] or [2], wherein R in the general formula (1) is an alkyl group or an alkenyl group having 14 to 22 carbon atoms.

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

[5] The defoamer for hydraulic compositions described in any one of [1] to [4], wherein the second condition further satisfies the condition of 6≦n+m≦50.

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

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

[8] A hydraulic composition, which is a defoamer for hydraulic compositions described in any one of [1] to [5], a polycarboxylic acid type dispersant, cement, and contains fine aggregates and/or Coarse aggregates are essential components.

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

Hereinafter, an embodiment of the defoamer for hydraulic compositions, the additive for hydraulic compositions, and the hydraulic composition 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 not limited to the following embodiments, without departing from the present invention. Changes, modifications, or improvements can be made within the scope of the invention.

1. Antifoaming agent (antifoaming agent for hydraulic composition)

An antifoaming agent of one embodiment of the present invention is a polyoxyalkylene compound represented by the following general formula (1), and satisfies the first condition: 0.02≦n/(n+m)<0.16; and Two conditions: 6≦n+m≦100; RO-[(EO)n/(AO)m]-H...(1).

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

That is, the defoamer of the present embodiment is a polyoxyalkylene compound represented by the above general formula (1), and the oxyethylene group (EO) and the oxyalkylene group (AO) are added by block addition or random addition ) Structure, and the average addition mole numbers of EO and AO both satisfy the first condition and the second condition shown above.

Furthermore, the defoamer of the present embodiment may have a "kneading 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. Range use. That is, the defoaming efficiency at low temperature is excellent. Here, the low temperature (time) regulation in this specification means the range of 0 degreeC or more and less than 18 degreeC.

Here, R in the general formula (1) is an alkyl group or alkenyl group having 8 to 30 carbon atoms, particularly preferably 14 to 22 carbon atoms. In particular, R can use residues obtained by removing hydroxyl groups from alcohols. The alcohols that can be used are not particularly limited, and may be, for example, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, Octadecanol, nonadecanol, eicosanol, twenty-one alcohol, behenyl alcohol, twenty-three alcohol, twenty-four alcohol, twenty-five alcohol, twenty-six alcohol, twenty-seven alcohol, twenty-eight alcohol Straight-chain alcohols such as alcohol, 29 alcohol and triocanol; 2-ethylhexanol, 2-propylheptanol, 2-butyloctanol, 1-methylheptadecanol, 2-hexyloctanol Alcohol, 2-hexyldecanol, isodecyl alcohol, isotridecyl alcohol, 3,5,5-trimethylhexanol and other branched chain alcohols; octenol, nonenol, decenol, undecenol , Dodecenol, tridecanol, tetradecenol, pentadecenol, hexadecenol, pentadecenol, hexadecenol, heptadecenol, octadecenol, nonapenol Eicosenol, Docosenol, Twenty-four-enol, Twenty-five-carbon dilute alcohol, Twenty-six-enol, Twenty-seven-enol, Twenty-eight-enol, 30 Straight-chain enols such as carbenols, thirty-three-carbon dilute alcohols, etc.; or branched-chain dilute alcohols such as 2-ethylhexenol, 1-methylheptadecanol, isoynyl alcohol, isostearyl alcohol, etc. . Furthermore, the alcohol used only as R may be used by selecting only one type from the above list, or two or more alcohols may be used in combination.

Furthermore, specific examples of alcohols that can be used are high-grade alcohols derived from natural oils and fats, KALCOL series (Kao Corporation), CONOL series (New Japan Physical and Chemical Corporation), FINEOXOCOL series (Nissan Chemical Industry Corporation), NEODOL series (SHELL CHEMICALS Ltd.), SAFOL series (SASOL), EXXAL series (EXXON MOBIL CORPORATION), etc.

On the other hand, AO (oxyalkylene group) in the general formula (1) is an oxyalkylene group having 3 to 18 carbon atoms. Examples of the oxyalkylene groups having 3 to 18 carbon atoms include oxypropylene groups, oxybutylene groups, oxyhexylene groups, oxyoctylene groups, and oxystyryl groups. In particular, AO is preferably an oxypropylene group. By this, high defoaming effect can be exerted at low temperature.

In addition, in the defoamer of the present embodiment, the second condition in the general formula (1) may also satisfy the condition of 6≦n+m≦50. That is, the aforementioned second condition may be set to a narrower range. By further restricting the range of the second condition, an excellent defoaming agent exhibiting high defoaming efficiency at low temperature can be obtained.

2. Additives for hydraulic compositions and hydraulic compositions

By using the defoaming agent as described above, the additive for hydraulic composition and the hydraulic composition can be obtained. Here, the additive for a hydraulic composition contains a polycarboxylic acid type dispersant and water as essential components in addition to the defoamer mentioned above. By this, an additive for a hydraulic composition that can radiate high defoaming performance at low temperatures can be obtained. On the other hand, in addition to the additives for the hydraulic composition, the hydraulic composition further contains cement as an essential component or cement and aggregate as an essential component. However, the additive for the hydraulic composition or the water contained in the hydraulic composition is a well-known substance, and therefore its detailed description is omitted here. Furthermore, as the aggregate contained in the hydraulic composition, fine aggregate such as sand and/or coarse aggregate such as gravel, crushed stone, groundwater slag, and recycled aggregate can be suitably used. In addition, the detailed description of the polycarboxylic acid type dispersant will be described later, and the description is omitted here.

3. Manufacturing method of antifoaming agent (polyoxyalkylene compound)

The method for producing the defoamer (polyoxyalkylene compound) of the present embodiment is not particularly limited, and a well-known production method can be used. For example, polyoxyalkylene compounds can be obtained by adding alkylene oxides to alcohols. Here, when adding alkylene oxide, a catalyst may be used, and as the catalyst, alkali catalysts such as hydroxides and alkoxides of alkali metals, alkaline earth metals or the like, or Lewis acid catalysts and composite metal catalysts may be used, especially alkaline catalysts. good.

Examples of usable basic catalysts include sodium, potassium, sodium-potassium amalgam, sodium hydroxide, potassium hydroxide, sodium hydride, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, and potassium butoxide. Sodium oxide, potassium hydroxide, sodium methoxide, potassium methoxide and potassium butoxide are particularly preferred.

On the other hand, examples of usable Lewis acid catalysts include tin tetrachloride, boron trifluoride, boron trifluoride ether complex, boron trifluoride di-n-butyl ether complex, and boron trifluoride Boron trifluoride compounds such as tetrahydrofuran complex, boron trifluoride phenol complex, boron trifluoride acetic acid complex, etc.

These catalysts can be neutralized and removed after the addition reaction, on the other hand, they can also be kept contained. The neutralization of the catalyst can be carried out by well-known techniques. For example, when the catalyst is an alkaline catalyst, acids such as hydrochloric acid, sulfuric acid, methanesulfonic acid, phosphoric acid, acetic acid, lactic acid, citric acid, succinic acid, or silicates such as aluminum silicate and magnesium silicate, activated clay, acid Adsorbents such as clay, silicone rubber, acidic ion exchange resin, etc. are used as neutralizing agents.

Furthermore, neutralization will be described more specifically. As commercially available adsorbents, for example, KYOWAAD600, 700 (respectively trade names of Kyowa Chemical Industry), MIZUKALIFEP-1, P-1S, P-1G, F-1G ( Silicates of Mizusawa Chemical Industry, TOMITA-AD600, 700 (respectively of Futian Pharmaceutical Factory), etc.; or DIAION (product name of Mitsubishi Chemical Corporation), AMBERLYST, AMBERLITE, DOWEX (respectively for DOW CHEMICALCOMPANY Chemical Co., Ltd.'s ion exchange resin, etc. Only one kind of neutralizing agent may be used, or two or more kinds of neutralizing agents may be used in combination.

The neutralization salts (neutralization products) generated by the neutralization of the catalyst can be further solid-liquid separated. For the solid-liquid separation method of neutralizing salts, for example, well-known filtration or centrifugal separation methods can be used. Here, the solid-liquid separation type caused by filtration uses, for example, filter paper, filter cloth, cartridge filter, two-layer filter of cellulose and polyester, metal mesh filter, metal sintered filter, etc. In the case of pressurization, the temperature is 20 to 140°C. On the other hand, the solid-liquid separation by centrifugal separation can be implemented with a centrifugal separator such as a decanter or a centrifugal clarifier. However, about 1 to 30 parts by mass of water can also be added to 100 parts by mass of the solution before solid-liquid separation according to needs. When the above solid-liquid separation requires special filtration, it is advisable to use filter aids to increase the filtration speed.

The filter aid used for filtration is not particularly limited, and examples thereof include diatomaceous earth, HYFLO SUPER CEL., CELL PURE series (trade name of ADVANCED MINERALS CORPORATION), silicon dioxide #645, silicon dioxide # Diatomite such as 600H, silica #600S, silica #300S, silica #100F (central SILICA trade name), white diatomite (GREFCO trade name); and ROKAHELPR (Mitsui Metal Mining (Trade name), TOPCO (trade name of Showa Chemical), perlite, etc.; KC-FLOCK (trade name of Japanese paper company), FIBERACELL (manufactured by ADVANCED MINERALS CORPORATION) and other cellulose-based filter aids; SAIROPYUTO (Fuji Silicone of Silysia Chemical Co., Ltd. etc.). In addition, only one kind of the above filter aid may be used, or two or more kinds may be used in combination.

Furthermore, a well-known thing can be used for a carboxylic acid type polycarboxylic acid type dispersant. For example, a copolymer containing a monomer represented by the following general formula (2) and an unsaturated carboxylic acid monomer can be exemplified.

R ¹ -OAR ² ... (2)

(Only, in the general formula (2), R ¹ is an alkenyl group having 2 to 5 carbon atoms or an unsaturated acetyl group having 3 or 4 carbon atoms, and A is a carbon atom having 2 to 4 carbon atoms or more. (Poly)oxyalkylene units with an average addition mole number of 1 to 500 composed of alkylene oxide groups, R ² represents a hydrogen atom or an alkyl group having 1 to 22 carbon atoms or an aliphatic group having 1 to 22 carbon atoms Acrylic.)

As the unsaturated carboxylic acid monomers, there are (meth)acrylic acid, crotonic acid and the like and their salts as the monocarboxylic acid type monomers, while the dicarboxylic acid monomers are maleic acid, itaconic acid, fumaric acid and the like And its equivalent. Among them, (meth)acrylic acid, maleic acid and their salts are particularly preferred. The salt is not particularly limited, but examples thereof include alkali metal salts such as sodium and potassium, alkaline earth metal salts such as magnesium and calcium, aluminum and iron metal salts, ammonium salts, and amine salts.

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

Furthermore, the carboxylic acid type polycarboxylic acid type dispersant can be produced by a known method. In addition, the copolymer can be produced by a known method. For example, the copolymer is synthesized by radical polymerization, and is obtained by mixing (heating) the above monomer, the unsaturated carboxylic acid monomer, and the third monomer with a radical initiator. Examples of the free radical accelerator used include potassium persulfate, ammonium persulfate, hydrogen peroxide, 2,2-azobis(2-amidinopropane) dihydrochloride, and azobisisobutyronitrile. These can be combined with reducing substances such as sulfite and L-ascorbic acid, or further combined with amines, etc., to be used as redox initiators. In order to make the mass average molecular weight of the obtained copolymer within the desired range, chain transfer agents such as 2-mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thioglycolic acid, mercaptoethanol, and thioglycerol can be used . In addition, water or an organic solvent may be used as a solvent for the polymerization, or a solvent may not be used.

Examples

Hereinafter, the defoaming agent of the present invention and the hydraulic composition containing the defoaming agent will be described based on the following examples and the like. However, the defoamer and hydraulic composition of the present invention are not limited to the following examples. The conditions for the specific method (addition reaction, etc.) used to produce the defoamer have already been described, and therefore detailed descriptions thereof are omitted here.

1. Synthesis of defoamer (polyoxyalkylene compound)

Initially, alcohols were used as R in the general formula (1) to synthesize an antifoaming agent (polyoxyalkylene compound). First, 128.3 g of alcohol A1 ("UNJECOL85AN (new Japanese physical and chemical trade name)") and 0.9 g of potassium hydroxide were added to a pressure vessel equipped with a stirrer, pressure gauge and thermometer. Alcohol A1 ("UNJECOL85AN") has a melting point of about 11°C, and is in a liquid state at room temperature around 20°C.

In this state, after dehydration treatment, while maintaining the reaction system in the pressure vessel at 110±5°C, 87.1 g of ethylene oxide was pressed in at a gauge pressure of 0.4 MPa for one hour, and then for two hours ripe. Furthermore, while maintaining the above-mentioned reflection system at 135±5°C, while pressing 706.5 g of propylene oxide at a gauge pressure of 0.4 MPa for five hours, the reaction was matured in two hours to complete the reaction.

After that, "KYOWAAD600 (trade name of Kyowa Chemical Industry Co., Ltd.)" was used as an adsorbent for neutralization treatment, and filtration purification was performed to obtain a purified product. According to the analysis results of NMR and gel permeation chromatography (converted to the mass average molecular weight of polystyrene) of this purified product, 4.1 mol of ethylene oxide and 2.2 mol of epoxy resin were sequentially added to 1.0 mol of lauryl alcohol. Propane defoamer af-1 (polyoxyalkylene compound). The measurement conditions of NMR and gel permeation chromatography are as follows.

Measurement conditions

(1) NMR

Device: Varian Mercury 300 (300MHz)

Nuclear species: 1H, 13C

Solvent: CDCl3

(2) Gel permeation chromatography

Device: HLC-8120GPC (TOSOH Corporation)

Column: TSK gel Super H4000+TSK gel Super H3000+TSK gel Super H2000 (TOSOH Co., Ltd.)

Detector: Differential Refractometer (RI)

Dissolution solution: Tetrahydrofuran

Flow rate: 0.5mL/min

Column temperature: 40℃

Sample concentration: 0.5% by mass of eluent solution

Standard material: Polystyrene (TOSOH Corporation)

The types of alcohols A1 to A4 used, alkylene oxide (oxypropylene group), addition order and amount of addition reaction, etc. were changed according to the conditions shown in Table 1 below. The synthesis of -1 is similar to the treatment to synthesize various defoamers af-2~af-6, af-e1, af-e2. The detailed information about the detailed characteristics or properties (linear/branched, saturated/unsaturated, carbon number, etc.) of the alcohols A1 to A4 used in the synthesis of the defoamer is shown in Table 2 below.

In the above Table 1, the defoamers af-1 to af-6 are synthesized to satisfy the first and second conditions of the defoamer of the present invention. On the other hand, defoamers af-e1 and af-e2 were synthesized without first conditions.

2. Synthesis of copolymers used in carboxylic acid polycarboxylic acid type dispersants and manufacture of dispersants

(1) Production Example 1 (Production of Dispersant SP-1)

Combine 140.1 grams of ion-exchanged water, 163.0 grams of α-methacryloyl-ω-methoxy-poly(n=9) ethylene oxide, 28.8 grams of methacrylic acid, 3.8 grams of 3-mercaptopropionic acid, and 9.9 grams of 30 % Aqueous sodium hydroxide solution is prepared in a reaction vessel with a thermometer, stirrer, dropping funnel, and nitrogen introduction tube. After stirring and dissolving uniformly, the ambient gas is replaced with nitrogen, and the temperature of the reaction system is reached 60°C in a warm water bath . Next, 63.9 g of 3.0% sodium persulfate aqueous solution was added to start the polymerization reaction. Two hours later, after adding 28.8 g of 3.0% sodium persulfate aqueous solution and maintaining at 60°C for two hours, the polymerization reaction was terminated. Thereafter, a 30% sodium hydroxide aqueous solution was added to adjust to pH 8, and the concentration was adjusted to 20% dispersant (SP-1) with ion-exchanged water.

(2) Production Example 2 (Production of Dispersant SP-2)

209.2 g of ion-exchanged water, 181.9 g of α-methyl-ω-methoxy-poly(n=45) oxyethylene, 15.8 g of methacrylic acid, and 2.0 g of 3-mercaptopropionic acid were prepared with The reaction vessel of the thermometer, stirrer, dropping funnel, and nitrogen introduction tube was dissolved while dissolving evenly while replacing the ambient gas with nitrogen, and the temperature of the reaction system was brought to 60°C in a warm water bath. Next, 27.7 g of a 1.0% aqueous hydrogen peroxide solution was dropped over 2.5 hours. Thereafter, 7.1 g of a 1.0% hydrogen peroxide aqueous solution was dropped over 3.5 hours, and the polymerization reaction was ended. Thereafter, a 30% sodium hydroxide aqueous solution was added to adjust to pH 9, and the concentration was adjusted with ion exchanged water to obtain a 20% dispersant (SP-2).

(3) Production Example 3 (Production of Dispersant SP-3)

Prepare 82.6 grams of ion-exchanged water and 175.7 grams of α-methallyl-ω-hydroxy-poly(n=113) oxyethylene in a reaction vessel with a thermometer, stirrer, dropping funnel, and nitrogen introduction tube, stirring After uniformly dissolving on one side, the ambient gas was replaced with nitrogen, and the temperature of the reaction system was brought to 60°C in a warm water bath. Next, 9.8 g of a 10.0% aqueous hydrogen peroxide solution was dropped in 3.0 hours, and at the same time, an aqueous solution of 11.7 g of acrylic acid and 7.8 g of hydroxyethyl acrylate dissolved in 97.6 g of ion-exchanged water was dropped in 3.0 hours. An aqueous solution in which 0.8 g of 3-mercaptopropionic acid and 1.0 g of ascorbic acid were dissolved in 7.0 g of ion-exchanged water was dropped in 4.0 hours. Thereafter, the temperature was maintained at 60°C for 0.5 hours, and the polymerization reaction was terminated. After that, 30% sodium hydroxide aqueous solution was added to adjust to pH 5, and adjusted to 20% concentration dispersant (SP-3) with ion-exchanged water.

The mass average molecular weight of the dispersant is measured by gel permeation chromatography in accordance with the measurement conditions shown below.

Measurement conditions

Device: Shodex GPC-101 (Showa Denko)

Column: OHpak SB-806M HQ+SB-806M HQ (Showa Denko)

Detector: Differential Refractometer (RI)

Eluent: 50mM aqueous solution of sodium nitrate

Flow rate: 0.7mL/min

Column temperature: 40℃

Sample concentration: 0.5% by mass of eluent solution

Standard materials: polyethylene glycol, polyethylene oxide (Agilent)

The water was removed from the dispersants SP-1 to SP-3 produced in each of Production Examples 1 to 5, and the solution was adjusted to a concentration of 5% using heavy water, and measured by NMR at 300 MHz. From this, it was confirmed that individual monomers had been polymerized into copolymers. Types of each component (component A, component B (component B1, component B2)) used in each of the dispersants SP-1 to SP-3 manufactured by Manufacturing Examples 1 to 5, and their respective masses (%) The average molecular weight of each of the dispersants SP-1 to SP-3 measured above and the values of pH are shown in Table 3 below.

However, in the description of Table 3 above, the following terms are used to indicate the following meanings.

L-1: α-methyl-ω-methoxy-poly(n=9) oxyethylene

L-2: α-methyl-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

3. The effect of defoaming effect caused by antifoaming agent

Next, the effect of the defoaming effectiveness of various synthesized antifoaming agents af-1 and the like (polyoxyalkylene compound) was confirmed. Initially, the concrete composition was prepared as shown below.

(1) Modulation of concrete composition

Adjust the temperature of each material to the target concrete temperature and use it. In the 55L forced twin-screw mixer, ordinary Portland cement (a blend of Pacific Cement, Ube Mitsubishi Cement, Sumitomo Osaka Cement, and the above three brands in equal amounts, specific gravity = 3.16) and fine bone as bone material The materials (Oikawa water system sand, specific gravity = 2.58) and coarse aggregate (Okazaki gravel, specific gravity = 2.66) were input at the mixing ratio shown in Table 4, and after 10 seconds of dry mixing, the fluidity became 18±2.5cm, the polycarboxylic acid type dispersants SP-1, SP-2 described in Table 3 and "AE-300 (trade name of Takemoto Oil and Fats Co., Ltd.)" as AE agent are 0.0025 relative to cement The mass %, defoamers af-1 to af-6, af-e1, af-e2 described in Table 1 are adjusted according to the types shown in Table 6 below. The added amount is added together with kneading water, and kneading is carried out for 90 seconds . Here, the defoamer af-1 and the like and the carboxylic acid polycarboxylic acid type dispersant SP-1 and the like are considered to be a part of kneaded water. In addition, similarly, at the mixing ratio shown in Table 5, the carboxylic acid-based polycarboxylic acid type dispersant SP-3 described in Table 3 and the defoaming agents af-1 to af-6 and af-e1 described in Table 1 were used. And af-e2 are kneaded in the types shown in Table 7 below.

(2) The effect of defoaming effectiveness

According to JIS-A1128, the "air volume (%)" was measured for the concrete composition immediately after kneading. The air volume (%) indicates the volume% of the hydraulic composition. Furthermore, while measuring the above-mentioned air volume (%), the "fluidity (cm)" was measured in compliance with JIS-A1101. Furthermore, the temperature immediately after kneading was measured in accordance with JIS-A1156 at the same time as the above-mentioned air volume (%) measurement. With the air volume (%) and the temperature immediately after kneading, the defoaming performance of the defoaming agent was confirmed. The measurement results are shown in Table 6 and Table 7 below.

In order to compare the results of defoaming efficacy, the amount of defoamer added for each formulation is fixed. From this, it can be confirmed that the defoamers af-1 to af-6 satisfying the first condition and the second condition of the present invention can exhibit a good Defoaming effect. Especially when the temperature immediately after kneading is less than 5°C, it can also exert good defoaming performance. On the other hand, it was also confirmed that when the defoamers af-e1 and af-e2 synthesized for comparison were used, the air volume (%) became higher especially when the kneading temperature was lower than 5°C (Comparative Example 1, 2, 4, 5). However, when the kneading temperature was 12°C, the value of the air volume (%) was slightly improved, but all showed lower defoaming efficiency (Comparative Examples 3 and 6). That is, it is confirmed that when the antifoaming agent of the present invention is used as one of the essential components of the hydraulic composition, it can exert a high antifoaming effect especially at low temperatures.

Industrial availability

The antifoaming agent for hydraulic compositions of the present invention can be used as an antifoaming agent when preparing hydraulic compositions. Furthermore, the additive for a hydraulic composition of the present invention can be used as an additive when preparing a hydraulic composition. The hydraulic composition of the present invention can be advantageously used in various building components or building components by using a defoaming agent that exhibits high defoaming performance at low temperatures.

Claims (12)

An antifoaming agent for hydraulic compositions is a polyoxyalkylene compound represented by the following general formula (1), RO-[(EO)n/(AO)m]-H...(1), and satisfies : The first condition: 0.02≦n/(n+m)<0.16; and the second condition: 6≦n+m≦100; where R is an alkyl or alkenyl group with 8 to 30 carbon atoms, and Straight or branched chain structure; EO is an oxyethylene group, AO is an alkylene oxide group with the same or different carbon number of 3 to 18; n and m are the average addition mole number, respectively, and n It is 1 or more, m is 1 or more, and [(EO)n/(AO)m] means that n moles of EO and m moles of AO are added or randomly added. The antifoaming agent for a hydraulic composition as described in claim 1 is used in a range where the kneading temperature immediately after kneading the hydraulic composition is 3°C or more and less than 15°C. The defoamer for a hydraulic composition according to claim 1, wherein R in the general formula (1) is an alkyl group or an alkenyl group having 14 to 22 carbon atoms. The defoamer for a hydraulic composition according to claim 2, wherein R in the general formula (1) is an alkyl group or an alkenyl group having 14 to 22 carbon atoms. The defoamer for a hydraulic composition according to claim 1, wherein the AO of the aforementioned general formula (1) is an oxypropylene group. The defoamer for a hydraulic composition according to claim 2, wherein the AO of the aforementioned general formula (1) is an oxypropylene group. The defoamer for a hydraulic composition according to claim 3, wherein the AO of the aforementioned general formula (1) is an oxypropylene group. The defoamer for a hydraulic composition according to claim 4, wherein the AO of the general formula (1) is an oxypropylene group. The defoamer for a hydraulic composition according to claim 1, wherein the second condition further satisfies the condition of 6≦n+m≦50. An additive for a hydraulic composition is a defoamer for a hydraulic composition described in claim 1, a carboxylic acid-based polycarboxylic acid type dispersant, and water as essential components. A hydraulic composition is a defoamer for hydraulic compositions described in claim 1, a carboxylic acid-based polycarboxylic acid type dispersant, and cement as essential components. A hydraulic composition comprising the defoamer for hydraulic composition described in claim 1, a carboxylic acid-based polycarboxylic acid type dispersant, cement, and aggregates containing fine aggregates and/or coarse aggregates as essential components .