TWI779048B - Defoamer for hydraulic composition, additive for hydraulic composition, and hydraulic composition - Google Patents

Abstract

The present invention provides a defoamer for hydraulic compositions, which is a polyoxyalkylene compound represented by the following general formula (1): RO-[(EO)n/(AO)m]-H...(1) , and satisfy the following relationship: the first condition: 0.02≦n/(n+m)<0.16; and the second condition: 6≦n+m≦100. However, R represents an alkyl or alkenyl group having 8 to 30 carbon atoms, and has a straight-chain or branched structure. EO means an oxyethylene group, and AO means an oxyalkylene group with 3 to 18 carbon atoms. n and m represent average added moles, respectively, 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 were added in bulk or randomly.

Description

Defoamer for hydraulic composition, additive for hydraulic composition, and hydraulic composition

The present invention relates to a defoamer for a hydraulic composition, an additive for a hydraulic composition, and a hydraulic composition, and more specifically relates to a defoamer for a hydraulic composition that exhibits high defoaming performance at low temperatures , an additive for a hydraulic composition including the antifoamer for a hydraulic composition, and a hydraulic composition including the antifoamer for a hydraulic composition.

Conventionally, the hydraulic composition is a hardened body obtained by kneading various materials such as a hydraulic binder and water, filling it into a mold, hardening it, and demolding the mold. In particular, the concrete composition, which is one of the hydraulic compositions, is formed by mixing and kneading various materials such as cement, water, aggregate, and dispersant, and then pouring it into a pre-prepared mold and allowing it to harden for a predetermined period of time. To be manufactured. Such a concrete composition has excellent strength and durability, and is widely used in various buildings or building structures to fully utilize the characteristics.

Here, in the concrete composition, additives (additives for hydraulic composition) are generally added in order to increase the air transport property and fluidity during kneading of various materials. By using such an additive, good dispersion properties can be maintained even when water reduction of the concrete composition has been performed. In addition, the handleability (workability) during kneading or application can be improved. Therefore, the durability, strength, and the like of the concrete composition can be improved, and a concrete composition, etc., that is excellent in stability over time and workability can be constructed.

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

At this time, when a polycarboxylic acid type dispersant and an AE agent are used in combination, an antifoaming agent (an antifoaming agent for a hydraulic composition) is generally used in order to eliminate many bubbles generated by the AE agent and the like. For example, a concrete composition containing polyoxyalkylene compounds, cement, water, fine aggregates, and coarse aggregates as essential components is known (see Patent Document 1). In this concrete composition, the polyoxyalkylene compound is, when the total added moles of the oxyethylene groups in the oxyalkylene groups is u, and the total added moles of the oxyalkylene groups with 3 or more carbon atoms is v , satisfy the relational formula of "0.15<u/(u+v)<0.9", and have at least one aliphatic hydrocarbon group with more than 5 continuous carbon atoms in the molecule. Thereby, it is possible to reduce the increase of the air volume as the kneading time is extended, and there is an advantage that the air delivery volume can be stably maintained. As a result, a high-quality concrete composition excellent in durability and strength can be provided.

That is, in the conventional technology, it is considered to use a highly hydrophobic substance as a defoamer for the concrete composition, but the hydrophilicity is improved by the oxyethylene group of the polyoxyalkylene compound, and the bubbles caused by the AE agent, etc. can be effectively suppressed generated, and the increase in the amount of air as the kneading time is prolonged can be suppressed. As a result, the air delivery rate can be stabilized without increasing the air volume.

[Prior technical literature]

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2003-226565

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

The polyoxyalkylene compound disclosed in the above-mentioned Patent Document 1 is effective in suppressing bubbles generated by AE agents and the like. However, this polyoxyalkylene compound may not exhibit sufficient defoaming performance at low temperatures. Especially when the temperature after kneading is lower than 10°C, the defoaming performance will drop sharply, and even if the amount of defoaming agent is increased, it is difficult to suppress the 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 conducted extensive studies and found a method for optimizing the oxyethylene group constituting the polyoxyalkylene compound in the polyoxyalkylene compound used as a defoamer for a hydraulic composition. The molar ratio and the total addition mole number of the oxyethylene group constituting the polyoxyalkylene compound and the oxyethylene group with 3 to 18 carbons are a defoamer for a hydraulic composition that exhibits high defoaming performance at low temperatures, The additive for hydraulic compositions containing this antifoamer for hydraulic compositions, and the hydraulic composition prepared containing these antifoamers for hydraulic compositions, etc.

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

According to the present invention, an antifoamer for a hydraulic composition, an additive for a hydraulic composition, and a hydraulic composition disclosed below are provided.

[1] A defoamer for a hydraulic composition, which is a polyoxyalkylene compound represented by the following general formula (1), and satisfies the following relationship: the 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 straight-chain or branched structure. EO means an oxyethylene group, and AO means an oxyalkylene group with 3 to 18 carbon atoms. n and m represent average added moles, respectively, 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 were added in bulk or randomly.

[2] The antifoaming agent for a hydraulic composition described in [1] can be used at a kneading temperature immediately after kneading the hydraulic composition within a range of 3°C to less than 15°C.

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

[5] The antifoaming agent for a hydraulic composition according to 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 defoamer for a hydraulic composition according to any one of [1] to [5], a polycarboxylic acid type dispersant, and water as essential components.

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

[8] A hydraulic composition comprising the defoamer for a hydraulic composition described in any one of [1] to [5], a polycarboxylic acid type dispersant, cement, and fine aggregates and/or The aggregate of the coarse aggregate is an essential component.

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

Hereinafter, embodiments of the defoamer for a hydraulic composition, the additive for a hydraulic composition, and the hydraulic composition of the present invention will be described. Here, the defoamer for hydraulic composition (hereinafter simply referred to as "defoamer"), the additive for hydraulic composition and the hydraulic composition of the present invention are not limited to the following embodiments, and without departing from the present invention Changes, corrections, or improvements are possible within the scope of the invention.

1. Defoamer (defoamer for hydraulic composition)

The defoamer 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 the second Two conditions: the relationship of 6≦n+m≦100; RO-[(EO)n/(AO)m]-H...(1).

In the above-mentioned general formula (1), "R" represents an alkyl or alkenyl group having 8 to 30 carbon atoms, and exhibits a linear or branched structure. In addition, "AO" means an oxyalkylene group with 3 to 18 carbon atoms, and "EO" means an oxyethylene group. On the other hand, n and m represent the average added moles, respectively, 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 were added in bulk or randomly.

That is, the antifoaming agent of this embodiment is a polyoxyalkylene compound represented by the above-mentioned general formula (1), and is a block addition or random addition of oxyethylene groups (EO) and oxyalkylene groups (AO ) composition, and the average added moles of EO and AO all satisfy the first condition and the second condition shown above.

Furthermore, the antifoaming agent of the present embodiment may have a "kneading temperature" immediately after the kneading of the hydraulic composition is 0°C or more and less than 18°C, more preferably 3°C or more and less than 15°C range of use. That is, the defoaming performance at low temperature is excellent. Here, the low temperature (hour) 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 or alkenyl group having 8 to 30 carbon atoms, particularly preferably 14 to 22 carbon atoms. In particular, for R, a residue obtained by removing a hydroxyl group from an alcohol can be used. The alcohols that can be used are not particularly limited, and can be, for example, octanol, nonanol, decyl alcohol, undecanol, dodecyl alcohol, tridecanol, tetradecyl alcohol, pentadecyl alcohol, cetyl alcohol, cetyl alcohol, Octadecanol, nonadecanol, eicosanol, hexacyl alcohol, behenyl alcohol, tricosanol, tetracyl alcohol, pentapentyl alcohol, hexacyl alcohol, hectahecanol, octacosanol Straight-chain alcohols such as alcohol, nonacosyl alcohol and triacontanol; 2-ethylhexanol, 2-propylheptanol, 2-butyloctanol, 1-methylheptadecanol, 2-hexyloctyl alcohol Alcohol, 2-hexyldecanol, isodecyl alcohol, isotridecanol, 3,5,5-trimethylhexanol and other branched alcohols; octenol, nonenol, decenyl alcohol, undecenol , Dodecenyl Alcohol, Tridecyl Alcohol, Tetradecyl Alcohol, Pentadecyl Alcohol, Hexadecenyl Alcohol, Pentadecyl Alcohol, Hexadecenyl Alcohol, Heptadecenyl Alcohol, Octadecenyl Alcohol, Nonadecenyl Alcohol Eicosenol, Docosenol, Tetracosenol, Hexacenol, Hexacenol, Heptacenol, Octacenol, Thirty Straight-chain enols such as carbenol and tritridecenyl alcohol; or branched-chain enols such as 2-ethylhexenol, 1-methylheptadecenol, isynyl alcohol, and isostearenyl alcohol, etc. . Furthermore, as the alcohol used only as R, only one kind selected from the above-mentioned ones may be used, or two or more kinds of alcohols may be used in combination.

Further, specific examples of alcohols that can be used are higher alcohols derived from natural oils and fats, KALCOL series (Kao Corporation), CONOL series (New Nippon Chemical Co., Ltd.), FINEOXOCOL series (Nissan Chemical Industry Co., Ltd.), 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) represents an oxyalkylene group having 3 to 18 carbon atoms. Examples of the oxyalkylene group having 3 to 18 carbon atoms include an oxypropylene group, an oxybutylene group, an oxyhexylene group, an oxyoctylene group, and an oxystyryl group. In particular, AO is preferably an oxypropylene group. Thereby, high defoaming performance can be exhibited at low temperature.

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 aforementioned second condition may also be set within a narrower range. By further limiting the range of the second condition, an excellent defoamer exhibiting high defoaming performance at low temperature can be obtained.

2. Additives for hydraulic compositions and hydraulic compositions

By using such an antifoaming agent, an additive for a hydraulic composition and a 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 above-mentioned antifoaming agent. Thereby, an additive for a hydraulic composition capable of exhibiting high defoaming performance even at low temperatures can be obtained. On the other hand, the hydraulic composition further contains cement as an essential component, or further contains cement and an aggregate as essential components, in addition to the above-mentioned additive for hydraulic composition. However, the additive for a hydraulic composition or the water contained in a hydraulic composition are well-known, and the 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, groundwater slag, and regenerated aggregates can be appropriately used. In addition, the detailed description of the polycarboxylic acid type dispersant will be described later, and the description will be omitted here.

3. Production method of antifoaming agent (polyoxyalkylene compound)

There are no particular limitations on the method for producing the antifoaming agent (polyoxyalkylene compound) of this embodiment, and a known production method can be used. Polyoxyalkylene compounds can be obtained, for example, by adding alkylene oxides to alcohols. Here, a catalyst can be used when adding an alkylene oxide. As the catalyst, a basic catalyst such as an alkali metal, an alkaline earth metal, or their hydroxide, alkoxide, or a Lewis acid catalyst and a composite metal catalyst can be used. good.

As the basic catalyst that can be used, for example, there are sodium, potassium, sodium potassium amalgam, sodium hydroxide, potassium hydroxide, sodium hydride, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, potassium butoxide, etc., and hydrogen Sodium oxide, potassium hydroxide, sodium methoxide, potassium methoxide, and potassium butoxide are particularly preferred.

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

These catalysts may be neutralized and removed after the addition reaction, or may be kept in a contained state. When neutralizing a catalyst, it can carry out by a well-known method. For example, when the catalyst is a basic catalyst, acids such as hydrochloric acid, sulfuric acid, methanesulfonic acid, phosphoric acid, acetic acid, lactic acid, citric acid, and succinic acid, or silicates such as aluminum silicate and magnesium silicate, activated clay, acidic acid, etc., can be used. Adsorbents such as clay, silica gel, and acidic ion exchange resin are used as neutralizing agents.

Further, neutralization will be described more specifically. As commercially available adsorbents, for example, KYOWAAD600, 700 (trade names of Kyowa Chemical Industry), MIZUKALIFEP-1, P-1S, P-1G, F-1G ( Silicates such as Mizusawa Chemical Industries), TOMITA-AD600, 700 (trade names of Tomita Pharmaceutical Co., Ltd. respectively); or DIAION (trade names of Mitsubishi Chemical Corporation), AMBERLYST, AMBERLITE, DOWEX (respectively Ion exchange resins such as DOW CHEMICAL COMPANY trade name) and the like. One of these neutralizing agents may be used alone, or two or more neutralizing agents may be used in combination.

The neutralized salts (neutralization product) generated by the neutralization of the catalyst can be further separated into solid and liquid. As a method for solid-liquid separation of neutralized salts, well-known techniques such as filtration or centrifugation can be used, for example. Here, the solid-liquid separation method by filtration uses, for example, filter paper, filter cloth, cartridge filter, double-layer filter of cellulose and polyester, metal mesh filter, metal sintered filter, etc. It is carried out at a temperature of 20 to 140°C under pressure. On the other hand, the solid-liquid separation by centrifugal separation can be implemented, for example, with a centrifugal separator such as a decanter or a centrifugal clarifier. However, 1 to 30 parts by mass of water may be added to 100 parts by mass of the solution before solid-liquid separation as required. When the above-mentioned solid-liquid separation needs to be filtered, it is advisable to use a filter aid to increase the filtration speed.

The filter aid used for filtration is not particularly limited, and examples include diatomaceous earth, HYFLO SUPER CEL., various series of CELL PURE (trade name of ADVANCED MINERALS CORPORATION), silica #645, silica # Diatomaceous earth such as 600H, silica #600S, silica #300S, silica #100F (trade names of CENTRAL SILICA, respectively), white diatomaceous earth (trade name of GREFCO); and ROKAHELPR (Mitsui Metal Mining Co., Ltd. Perlite such as TOPCO (trade name of Showa Chemicals), etc.; KC-FLOCK (trade name of Nippon Paper Corporation), cellulose-based filter aids such as FIBERACELL (manufactured by ADVANCED MINERALS CORPORATION); SAIROPYUTO (Fuji Silysia Chemical Co., Ltd.'s trade name) and other silicone rubber. Moreover, only 1 type of said filter aid may be used, or 2 or more types may be used together.

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-based monomer is exemplified.

R ¹ -OAR ² ...(2)

(Only, in the general formula (2), R1 represents an alkenyl group with ² to 5 carbon atoms or an unsaturated acyl group with 3 or 4 carbon atoms, and A is one or more than two types of alkenyl groups with 2 to 4 carbon atoms. The (poly)oxyalkylene unit formed by the oxyalkylene group with an average addition mole number of ¹ to 500, R2 represents a hydrogen atom or represents an alkyl group with 1 to 22 carbons or an aliphatic group with 1 to 22 carbons Acyl group.)

As the unsaturated carboxylic acid monomer, there are (meth)acrylic acid, crotonic acid, etc. and their salts as the monocarboxylic acid type monomer, and maleic acid, itaconic acid, fumaric acid, etc. as the dicarboxylic acid type monomer. and its salt. Among them, salts of (meth)acrylic acid, maleic acid and the like are particularly preferable. 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, metal salts of aluminum and iron, ammonium salts, and amine salts.

In the copolymer, a copolymer can be obtained by reacting any appropriate 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 salt, (meth)acrylamide, acrylonitrile, (meth)acrylate, etc. can be used.

Furthermore, the carboxylic acid type polycarboxylic acid type dispersant can be manufactured by a well-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-mentioned monomers, unsaturated carboxylic acid monomers, and a third monomer with a radical promoter. Examples of the radical generator used include potassium persulfate, ammonium persulfate, hydrogen peroxide, 2,2-azobis(2-amidinopropane) dihydrochloride, azobisisobutyronitrile, and the like. These can be used as redox initiators in combination with reducing substances such as sulfite and L-ascorbic acid, or further with amines. In order to make the mass average molecular weight of the resulting copolymer within the desired range, chain transfer agents such as 2-mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, mercaptoacetic acid, mercaptoethanol and thioglycerol can be used. . In addition, in the polymerization, water or an organic solvent may be used as a solvent, or no solvent may be used.

Example

Hereinafter, the antifoaming agent of the present invention and the hydraulic composition containing the antifoaming agent will be described based on the following examples and the like. However, the antifoaming agent and hydraulic composition of this invention are not limited to the following examples. Since the conditions of the specific method (addition reaction, etc.) for producing the antifoaming agent have already been described, detailed description thereof will be omitted here.

1. Synthesis of defoamer (polyoxyalkylene compound)

Initially, an antifoaming agent (polyoxyalkylene compound) was synthesized using alcohols as R in the general formula (1). First, 128.3 g of alcohol A1 ("UNJECOL 85AN (trade name of Nippon Chemical)") and 0.9 g of potassium hydroxide were placed in a pressure vessel equipped with a stirrer, a pressure gauge, and a 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 the 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 reaction system at 135±5°C, 706.5 g of propylene oxide was injected at a gauge pressure of 0.4 MPa for five hours and then matured for two hours to complete the reaction.

Thereafter, neutralization treatment was performed using "KYOWAAD600 (trade name of Kyowa Chemical Industry Co., Ltd.)" as an adsorbent, and purification by filtration was performed to obtain a purified product. The purified product, according to the analysis results of NMR and gel permeation chromatography (converted to the mass average molecular weight of polystyrene), is to add 4.1 moles of ethylene oxide and 2.2 moles of epoxy to 1.0 moles of lauryl alcohol. Propane antifoaming agent 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 Co., Ltd.)

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

Detector: Differential Refractometer (RI)

Eluent: Tetrahydrofuran

Flow rate: 0.5mL/min

Column temperature: 40°C

Sample concentration: eluent solution with a sample concentration of 0.5% by mass

Standard material: polystyrene (TOSOH Co., Ltd.)

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

In the above Table 1, the defoamers af-1~af-6 are synthesized to satisfy the first condition and the second condition of the defoamer of the present invention. On the other hand, the defoamers af-e1 and af-e2 are synthesized away from the first condition.

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

(1) Manufacturing Example 1 (Manufacture of Dispersant SP-1)

140.1 grams of ion-exchanged water, 163.0 grams of α-methacryl-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 % sodium hydroxide aqueous solution is prepared in a reaction vessel with a thermometer, a stirrer, a dropping funnel and a nitrogen gas inlet pipe, and the ambient gas is replaced with nitrogen after stirring while uniformly dissolving, and the temperature of the reaction system reaches 60°C in a warm water bath . Next, 63.9 g of a 3.0% aqueous solution of sodium persulfate was added to start polymerization. Two hours later, 28.8 g of a 3.0% aqueous solution of sodium persulfate was added and maintained at 60°C for two hours to terminate the polymerization. After that, 30% sodium hydroxide aqueous solution was added to adjust the pH to 8, and the concentration was adjusted to 20% dispersant (SP-1) with ion-exchanged water.

(2) Manufacturing Example 2 (Manufacture of Dispersant SP-2)

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

(3) Manufacturing Example 3 (Manufacture of Dispersant SP-3)

82.6 grams of ion-exchanged water and 175.7 grams of α-methallyl-ω-hydroxyl-poly(n=113)oxyethylene were prepared in a reaction vessel with a thermometer, a stirrer, a dropping funnel and a nitrogen inlet tube, and stirred After one side was uniformly dissolved, the ambient gas was replaced with nitrogen, and the temperature of the reaction system was brought to 60° C. with a warm water bath. Then, 9.8 grams of 10.0% hydrogen peroxide aqueous solution was dripped for 3.0 hours, and at the same time, 97.6 grams of ion-exchanged water was dissolved with 11.7 grams of acrylic acid, and 7.8 grams of hydroxyethyl acrylate was dripped for 3.0 hours, and at the same time 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 dripped over 4.0 hours. Thereafter, 60° C. was maintained for 0.5 hours, and the polymerization reaction was terminated. Afterwards, 30% sodium hydroxide aqueous solution was added to adjust the pH to 5, and ion-exchanged water was used to adjust to a dispersant (SP-3) with a concentration of 20%.

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 sodium nitrate aqueous solution

Flow: 0.7mL/min

Column temperature: 40°C

Sample concentration: eluent solution with a sample concentration of 0.5% by mass

Standard material: polyethylene glycol, polyethylene oxide (Agilent)

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 300 MHz NMR. Thereby, it was confirmed that individual monomers had been polymerized into copolymers. Types of components (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, and their respective mass (%) And the average molecular weight of each dispersant SP-1-SP-3 measured above, and the value of pH are shown in following Table 3.

However, in the description in Table 3 above, the following terms have 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 performance caused by defoaming agent

Next, the effect of the defoaming performance of various synthesized defoamers af-1 and the like (polyoxyalkylene compounds) was confirmed. Initially, the concrete composition was prepared as follows.

(1) Modulation of concrete composition

Adjust the temperature of each material to the target concrete temperature and use it. In a 55L forced twin-screw mixer, Ordinary Portland cement (mixed with Pacific Cement, Ube Mitsubishi Cement, Sumitomo Osaka Cement, the above three brands in equal amounts, specific gravity = 3.16) and fine bone as aggregate Material (Oigawa river system sand, specific gravity = 2.58) and coarse aggregate (Okazaki crushed stone, specific gravity = 2.66) were added at the mixing ratio shown in Table 4, and dry-mixed for 10 seconds so that the fluidity became 18 ± 2.5cm, the polycarboxylic acid type dispersant SP-1, SP-2 recorded in Table 3 and "AE-300 (trade name of Takemoto Oil Co., Ltd.)" as the AE agent were 0.0025 to the cement. Mass %, defoamers af-1~af-6, af-e1, af-e2 listed in Table 1 are added according to the type shown in Table 6, and added together with kneading water, and kneaded for 90 seconds . Here, the antifoaming agent af-1 etc. and the carboxylic acid type polycarboxylic acid type dispersant SP-1 etc. are regarded as a part of kneading water. Again, similarly with the mixing ratio shown in Table 5, the carboxylic acid polycarboxylic acid type dispersant SP-3 recorded in Table 3 and the defoamer af-1~af-6, af-e1 recorded in Table 1 were mixed. , af-e2 were kneaded by the kind shown in following Table 7.

(2) The effect of defoaming performance

"Air volume (%)" was measured on the concrete combination immediately after kneading in accordance with JIS-A1128. The amount of air (%) represents the volume % of the hydraulic composition. Furthermore, the "fluidity (cm)" was measured in accordance with JIS-A1101 while measuring the above-mentioned air volume (%). Furthermore, simultaneously with the above air amount (%) measurement, the temperature immediately after kneading was measured in accordance with JIS-A1156. The defoaming performance of the defoamer is confirmed by the air volume (%) and the temperature immediately after kneading. 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 was fixed for each formulation. 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 exhibit good performance at a low temperature such as 5°C or 12°C immediately after kneading. Defoaming effect. Especially when the temperature immediately after kneading is lower 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 (%) increased especially when the kneading temperature was lower than 5°C (Comparative Example 1, 2, 4, 5). However, when the kneading temperature is 12°C, the value of the air content (%) is slightly improved but all show lower defoaming performance (Comparative Examples 3 and 6). That is, it was confirmed that the antifoaming agent of the present invention exhibits high antifoaming performance especially at low temperatures when used as one of the essential components of the hydraulic composition.

Industrial availability

The antifoaming agent for hydraulic compositions of this invention can be used as an antifoaming agent when preparing a hydraulic composition. Furthermore, the additive for hydraulic compositions of this invention can be used as an additive when preparing a hydraulic composition. The hydraulic composition of the present invention can be advantageously used in construction parts of various buildings or construction parts by using a defoamer capable of exhibiting high defoaming performance at low temperature.

Claims (7)

A defoamer for a hydraulic composition, which is used when the kneading temperature of the hydraulic composition immediately after kneading is 3°C or more and less than 15°C, and is a polyoxygen compound represented by the following general formula (1): Alkene compound, RO-[(EO)n/(AO)m]-H...(1), and satisfy: the first condition: 0.02≦n/(n+m)<0.16; and the second condition: 6 The relationship of ≦n+m≦47; where R represents an alkyl or alkenyl group with 8 to 30 carbons, and is in a straight-chain or branched structure; EO represents an oxyethylene group, and AO represents the same or different An oxyalkylene group with 3 to 18 carbons; n and m represent the average added moles respectively, and n is more than 1, and m is more than 1. In addition, [(EO)n/(AO)m] is Indicates that n moles of EO and m moles of AO were added in blocks in the order of EO, AO or AO, EO, AO. The defoamer for hydraulic compositions as described in Claim 1, wherein R in the aforementioned general formula (1) is an alkyl or alkenyl group having 14 to 22 carbon atoms. The antifoaming agent for a hydraulic composition as described in Claim 1, wherein AO in the aforementioned general formula (1) is an oxypropylene group. The antifoaming agent for a hydraulic composition as described in claim 2, wherein AO in the aforementioned general formula (1) is an oxypropylene group. An additive for a hydraulic composition, comprising the defoamer for a hydraulic composition described in claim 1, a carboxylic acid polycarboxylic acid type dispersant, and water as essential components. A hydraulic composition comprising the defoamer for a hydraulic composition described in Claim 1, a carboxylic acid polycarboxylic acid type dispersant, and cement as essential components. A hydraulic composition comprising the defoamer for the hydraulic composition described in claim 1, a carboxylic acid polycarboxylic acid type dispersant, cement, and aggregates containing fine aggregates and/or coarse aggregates as essential components .