JP5328208B2 - Admixture for hydraulic composition - Google Patents

Description

  The present invention relates to an admixture for a hydraulic composition.

  In fresh concrete, the standard range of fluidity is defined from shipment to placement, and it is required to maintain this standard range of fluidity. If the flowability of the fresh concrete falls outside the standard range, the fresh concrete cannot be placed, and will be returned (subject to claims). For this reason, it is important to maintain the fluidity of fresh concrete within the standard range. Conventionally, for example, in a polycarboxylic acid-based admixture using an unsaturated carboxylic acid monomer and a monomer having a polyoxyethylene chain, a so-called ternary polymer using three kinds of constituent monomers is mixed with cement. In combination with the agent, the fluidity has been kept within the standard range.

  In recent years, the versatility of materials and the lowering of viscosity of concrete are progressing. For this purpose, in binary polycarboxylic acid polymers having polyoxyethylene chains, the ethylene oxide chain length is changed from long to short. It is known that migrating is effective. For this reason, it is desirable to use a binary polymer having a short ethylene oxide chain in applications where a high degree of viscosity reduction is required. However, the ternary polymer is used in combination with such a polymer. However, since the flow value greatly exceeds the standard range, there is a problem that the flow value cannot be maintained within the standard range.

Regarding the polycarboxylic acid-based cement admixture, Patent Documents 1 and 2 disclose a cement admixture containing a polycarboxylic acid-based polymer and polyethylene glycol as essential components, and Patent Document 3 discloses a specific binary system or It is disclosed that a polycarboxylic acid-based high-performance water reducing agent can be used in combination with a cement admixture made of a ternary polymer. Patent Documents 4 and 5 disclose that a cement additive containing a butyl carbitol derivative and polyethylene glycol can be used in combination with a polycarboxylic acid-based cement dispersant.
JP-A-6-64956 JP 2003-252666 A JP-A-10-81549 JP-A-10-167786 Japanese Patent Laid-Open No. 8-198653

  However, the admixtures and additives described in Patent Documents 1 to 5 have a limit in fluid retention performance, and sufficient fluid retention performance cannot be obtained.

  An object of the present invention is to provide an admixture for a hydraulic composition capable of expressing excellent initial fluidity and sufficient fluidity retention for a hydraulic composition containing a hydraulic powder. .

The present invention relates to an admixture for a hydraulic composition containing the following components (A) to (C).
<(A) component>
A copolymer (A-1) obtained by polymerizing a monomer represented by the following general formula (A1) and a monomer represented by the following general formula (A2) [hereinafter referred to as copolymer (A- 1)], a monomer represented by the following general formula (A1), a monomer represented by the following general formula (A3), and a monomer represented by the following general formula (A4) One or more copolymers selected from the group consisting of copolymer (A-2) [hereinafter referred to as copolymer (A-2)]

[Wherein, R ^1a and R ^2a each independently represents a hydrogen atom or a methyl group. AO is an oxyalkylene group having 2 to 3 carbon atoms, n1 is the average number of added moles of AO, and represents a number of 6 to 30. X ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ]

[In formula, R ^<3a> , R ^<4a> , R ^<5a> represents a hydrogen atom or a methyl group each independently. M ^1a represents a hydrogen atom, a monovalent metal, or an ammonium group which may have a substituent. ]

[Wherein, R ^6a represents a hydrogen atom or a methyl group. R ^7a represents an alkylene group having 2 to 6 carbon atoms. M ^2a and M ^3a each independently represent a hydrogen atom, an alkali metal, or an alkaline earth metal (1/2 atom). m1 is the average added mole number of OR ^7a and represents a number of 1 to 30. ]

[Wherein, R ^8a and R ^10a each represent a hydrogen atom or a methyl group. R ^9a and R ^11a each independently represents an alkylene group having 2 to 6 carbon atoms. M ^4a represents a hydrogen atom, an alkali metal or an alkaline earth metal (1/2 atom). m2 and m3 are the average added mole numbers of OR ^9a and OR ^11a , respectively, and each independently represents a number of 1 to 30. ]

<(B) component>
A copolymer obtained by polymerizing a monomer represented by the following general formula (B1), a monomer represented by the following general formula (B2), and a monomer represented by the following general formula (B3)

[Wherein, R ^1b and R ^2b each independently represents a hydrogen atom or a methyl group. AO is an oxyalkylene group having 2 to 3 carbon atoms, n2 is the average number of added moles of A′O, and represents a number of 110 to 150. X ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ]

[Wherein, R ^3b , R ^4b and R ^5b each independently represents a hydrogen atom or a methyl group. M ^1b represents a hydrogen atom, a monovalent metal, or an ammonium group which may have a substituent. ]

[R ^6b represents a hydrogen atom or a methyl group. R ^7b represents a C 1-8 alkyl group, a C 2-8 alkenyl group, or a C 2-6 hydroxy group-containing alkyl group. ]

<(C) component>
Polyethylene glycol having a weight average molecular weight of 1000 to 90000

  ADVANTAGE OF THE INVENTION According to this invention, the admixture for hydraulic compositions which can express the outstanding initial fluidity | liquidity and fluid holding | maintenance property with respect to the hydraulic composition containing hydraulic powder is provided.

<(A) component>
The component (A) of the present invention is a copolymer (A-1) obtained by polymerizing the monomer represented by the general formula (A1) and the monomer represented by the general formula (A2). And a monomer obtained by polymerizing the monomer represented by the general formula (A1), the monomer represented by the general formula (A3), and the monomer represented by the general formula (A4). It is at least one copolymer selected from the group consisting of polymers (A-2). The component (A) of the present invention contributes to the expression of initial fluidity.

<Copolymer (A-1)>
The copolymer (A-1) of the present invention comprises a monomer represented by the general formula (A1) [hereinafter referred to as the monomer (A1)] and a single monomer represented by the general formula (A2). It is obtained by copolymerizing a monomer containing a body [hereinafter referred to as monomer (A2)].

  The monomer (A1) is an ethylenically unsaturated monomer having 6 to 30 moles of an oxyalkylene group having 2 to 3 carbon atoms, and examples thereof include methoxypolyalkylene glycol and (meth) acrylic acid esters.

  As the monomer (A1), methoxypolyethylene glycol, methoxypolyethylenepolypropylene glycol, ethoxypolyethyleneglycol, ethoxypolyethylenepolypropyleneglycol, propoxypolyethyleneglycol, propoxypolyethylenepolypropyleneglycol, etc., one-end alkyl-capped polyalkyleneglycol and acrylic acid or methacrylic acid Or an adduct of ethylene oxide and / or propylene oxide to acrylic acid or methacrylic acid. The average addition mole number n1 of the oxyalkylene group is 6 to 30, and both additions of ethylene oxide and propylene oxide can be used in any of random addition, block addition, alternating addition, and the like. From the viewpoint of dispersibility with respect to the hydraulic composition and the effect of imparting viscosity, the average added mole number is preferably 7 or more, and more preferably 8 or more. Further, from the viewpoint of polymerizability and fluidity imparting property, n1 is preferably 28 or less, and more preferably 25 or less.

  The monomer (A1) is obtained by reacting an acid having an unsaturated bond with polyalkylene glycol or a derivative obtained by alkyl etherifying one end thereof. Examples of the acid having an unsaturated bond include carboxylic acids such as acrylic acid and methacrylic acid, and one or two or more selected from these groups can be used, but a monocarboxylic acid is more preferable. .

  Examples of the acrylic acid monomer of the monomer (A2) used in the present invention include acrylic acid, methacrylic acid, crotonic acid, and metal salts thereof.

  The copolymer (A-1) obtained by polymerizing the monomer (A1) and the monomer (A2) can be produced by a method such as polymerization in a solvent or bulk polymerization.

  The synthesis in the solvent can be carried out batchwise or continuously. Examples of the solvent include water, lower alcohols, aromatic hydrocarbons, aliphatic hydrocarbons, and ketone compounds, but water, methyl alcohol, ethyl alcohol, isopropyl alcohol, and water / lower alcohol mixed systems are preferable from the viewpoint of workability. . As the polymerization initiator in the case of performing polymerization in an aqueous system, ammonium or alkali metal persulfate, hydrogen peroxide, and the like are suitable. The polymerization temperature is preferably 0 to 120 ° C.

  As the polymerization initiator for bulk polymerization, a peroxide such as benzoyl peroxide and an aliphatic azo compound such as azobisisobutyronitrile are preferable. The polymerization temperature is preferably 40 ° C to 160 ° C.

  As the polymerization initiator for bulk polymerization, a peroxide such as benzoyl peroxide and an aliphatic azo compound such as azobisisobutyronitrile are preferable. The polymerization temperature is preferably 40 ° C to 160 ° C.

  The copolymer (A-1) preferably has a weight average molecular weight (Mw) of 5,000 to 500,000, further 20,000 to 100,000, and more preferably 30,000 to 85,000. This weight average molecular weight is measured by a gel permeation chromatography method (in terms of standard substance sodium polystyrene sulfonate).

<Copolymer (A-2)>
The copolymer (A-2) of the present invention is a phosphoric acid polymer, and the monomer (A1) and the monomer represented by the general formula (A3) [hereinafter, the monomer (A3) And a monomer containing the monomer represented by the general formula (A4) [hereinafter referred to as the monomer (A4)], preferably at a pH of 7 or less It is a coalescence.

  As such a monomer (A3) (monoester) and a monomer (A4) (diester form), a mixed monomer containing them can be used, and specifically includes a monoester form and a diester form. Commercially available products can be used, for example, Phosmer M, Phosmer PE, Phosmer P (Unichemical), JAMP514, JAMP514P, JMP100 (all Johoku Chemical), Light Ester P-1M, Light Acrylate P-1A (all Kyoeisha Chemical), MR200 (Daihachi Chemical), Kayamar (Nippon Kayaku), Ethyleneglycolate phosphate (Aldrich Reagent), and the like.

The mixed monomer including the monomer (A3) and the monomer (A4) is, for example, an organic hydroxy compound represented by the general formula (A6), phosphoric anhydride (P ₂ O ₅ ), and water. It can also manufacture as a reaction product by making it react with a predetermined preparation ratio.

[Wherein, R ^12a represents a hydrogen atom or a methyl group, R ^13a represents an alkylene group having 2 to 12 carbon atoms, and m4 represents a number of 1 to 30. ]

  The monomer (A3) and the monomer (A4) are phosphoric acid ester products of monomers having an unsaturated bond and a hydroxyl group, and the above-mentioned commercially available products and reaction products include monoester compounds (single amount). (A3)) and a diester (monomer (A4)) are included. These other compounds are considered to be a mixture of polymerizable and non-polymerizable compounds. In the present invention, such a mixture can be used as it is.

The contents of the monomer (A3) and the monomer (A4) in the mixture can be calculated based on the ³¹ P-NMR measurement result.
< ³¹ P-NMR measurement conditions>
・ Inverse-gated-decoupling method
・ Measurement range 6459.9Hz
・ Pulse delay time 30 sec
Observation data point 10336
・ Pulse width (5.833 μsec) 35 ° pulse ・ Solvent CD ₃ OH (deuterated methanol) (concentration 30% by weight during measurement)
・ Number of integration 128

  From the signal of the obtained chart, it is possible to determine the relative quantitative ratio from the area ratio of the signal assigned to each compound as in the following example.

For example, when the organic hydroxy compound is a phosphorous oxide of “2-hydroxyethyl methacrylate”, it can be assigned as follows.
1.8 ppm to 2.6 ppm: phosphoric acid0.5 ppm to 1.1 ppm: monomer 2 (monoester)
-0.5 ppm to 0.1 ppm: monomer 3 (diester form)
-1.0 ppm to -0.6 ppm: triester form--11.1 ppm to -10.9 ppm, -12.4 ppm to -12.1 ppm: pyrophosphoric acid monoester, -12.0 ppm to -11.8 ppm: Pyrophosphate diester -11.2 to -11.1 ppm: Pyrophosphate -Other peaks: Unknown

  In the present invention, the phosphoric acid content in the mixed monomer was quantified to determine the ratio of the monomer (A3) and the monomer (A4) in the mixed monomer. Specifically, the calculation is performed as follows.

  The absolute amount (% by weight) of the phosphoric acid content in the sample is determined by gas chromatography. Since the relative molar ratio of phosphoric acid, mono-isomer and di-isomer in the sample can be obtained from the result of P-NMR, the absolute amounts of mono-isomer and di-isomer were calculated based on the absolute amount of phosphoric acid.

[Phosphoric acid content]
The conditions for gas chromatography are as follows.
Sample: Methylation with diazomethane Example) Methylation by adding 1-1.5 cc of diazomethane in diethyl ether to 0.1 g sample Column: Ultra ALLOY, 15 m × 0.25 mm (inner diameter) × 0.15 μmdf
Carrier gas: He, split ratio 50: 1
Column temperature: 40 ° C. (5 min) (hold) → 10 ° C./min (temperature rise) → 15 min after reaching 300 ° C. Hold inlet temperature: 300 ° C.
Detector temperature: 300 ° C
Under the above conditions, a peak derived from phosphoric acid is detected around 9 minutes, and the phosphoric acid content in the unknown sample can be calculated by a calibration curve method.

  As described above, industrially, phosphate ester monomers are usually available as a mixture containing a monoester (monomer (A3)) and a diester (monomer (A4)). Among these, since diesters are likely to have a high molecular weight (gelation) by crosslinking, such a mixture is restricted in production in fields using the properties, for example, thickeners, adhesives, coatings, etc. Can be used suitably without receiving much. On the other hand, in admixtures for hydraulic compositions (dispersants, water reducing agents, etc.), polymers containing phosphate groups are preferable because of their excellent adsorptive power to hydraulic substances, but dispersibility and viscosity are reduced by increasing the molecular weight. The effect is lowered, which is not preferable from the viewpoint of handleability. However, it is industrially disadvantageous to separate the monoester form and the diester form from the mixture of phosphate esters as raw materials from the application and economical properties of the hydraulic composition.

  From the viewpoint of fluidity and viscosity-reducing properties, it is better to use a mixture of phosphate esters containing a large amount of monoester, but even when containing a large amount of diester, monomer (A1) and By controlling the copolymerization molar ratio, fluidity and viscosity reduction can be adjusted.

  When the monomers are copolymerized, the molar ratio of the monomer (A1) to the monomer (A3) and the monomer (A4) is as follows: monomer (A1) / [monomer (A3) + Monomer (A4)] = 5/95 to 95/5, more preferably 10/90 to 90/10. The molar ratio of monomer (A1), monomer (A3), and monomer (A3) is as follows: monomer (A1) / monomer (A3) / monomer (A4) = 5. 95/3 to 90/1 to 80 (this means that the monomer (A1) is 5 to 95, the monomer (A3) is 3 to 90, and the monomer (A4) is 1 to 80. However, the total is 100), and more preferably 5 to 96/3 to 80/1 to 60. In addition, about a monomer (A3) and a monomer (A4), a molar ratio and mol% shall be computed based on an acid type compound.

  In the production method for obtaining the copolymer (A-2) of the present invention, it is preferable to react the monomer (A1), the monomer (A3), and the monomer (A4) at a pH of 7 or less. In the present invention, the pH at 20 ° C. of the reaction solution collected during the reaction (from the start of the reaction to the end of the reaction) is defined as the pH during the reaction. Usually, the reaction may be started under conditions that clearly show that the pH during the reaction is 7 or less (monomer ratio, solvent, other components, etc.). Further, it is preferable to use a chain transfer agent or a polymerization initiator, or a solution polymerization method.

  The phosphate ester polymer of the copolymer (A-2) preferably has a weight average molecular weight (Mw) of 10,000 to 150,000. Moreover, it is preferable that Mw / Mn is 1.0-2.6. Here, Mn is the number average molecular weight. Mw is preferably 10,000 or more, more preferably 12,000 or more, still more preferably 13,000 or more, still more preferably 14,000 or more, and even more preferably 15 from the viewpoint of expression of the dispersion effect and viscosity reduction effect. 15,000 or less, preferably 150,000 or less, more preferably 130,000 or less, and still more preferably 120,000 from the viewpoints of high molecular weight by crosslinking, suppression of gelation, and performance in terms of dispersion effect and viscosity reduction effect. Or less, more preferably 110,000 or less, still more preferably 100,000 or less. Therefore, from the viewpoints of the both, preferably 12,000 to 130,000, more preferably 13,000 to 120,000, More preferably, 14,000 to 110,000, still more preferably 15,000 to 100,000. A. It is preferable to have Mw in this range and Mw / Mn is 1.0 to 2.6. Here, the value of Mw / Mn represents the degree of dispersion of the molecular weight distribution, and the closer to 1, the closer the molecular weight distribution to monodispersion, and the farther from 1 (larger), the wider the molecular weight distribution.

Mw and Mn of the copolymer (A-2) are those measured by a gel permeation chromatography (GPC) method under the following conditions. In addition, Mw / Mn of the copolymer (A-2) in this invention shall be computed based on the peak of this polymer. [GPC conditions]
Column: G4000PWXL + G2500PWXL (Tosoh)
Eluent: 0.2M phosphate buffer / CH ₃ CN = 9/1
Flow rate: 1.0mL / min
Column temperature: 40 ° C
Detection: RI
Sample size: 0.2mg / mL
Reference material: Polyethylene glycol equivalent

<(B) component>
The component (B) of the present invention is a copolymer different from the copolymer (A-1), and is a monomer represented by the general formula (B1) [hereinafter referred to as monomer (B1)]. , A monomer represented by the above general formula (B2) [hereinafter referred to as monomer (B2)] and a monomer represented by the above general formula (B3) [hereinafter referred to as monomer (B3)] It is obtained by copolymerizing the monomer containing. The component (B) of the present invention contributes to developing fluidity retention over time.

  The monomer (B1) is an ethylenically unsaturated monomer having 110 to 150 moles of an oxyalkylene group having 2 to 3 carbon atoms, such as an ester of methoxypolyalkylene glycol and (meth) acrylic acid, or polyalkylene glycol. Examples include monoallyl ether.

  As the monomer (B1), methoxypolyethylene glycol, methoxypolyethylenepolypropylene glycol, ethoxypolyethyleneglycol, ethoxypolyethylenepolypropyleneglycol, propoxypolyethyleneglycol, propoxypolyethylenepolypropyleneglycol, etc., one-end alkyl-capped polyalkyleneglycol and acrylic acid or methacrylic acid Or an adduct of ethylene oxide and / or propylene oxide to acrylic acid or methacrylic acid. The average addition mole number n2 of the oxyalkylene group is 110 to 150, and both additions of ethylene oxide and propylene oxide can be used in any of random addition, block addition, alternating addition, and the like. From the viewpoint of not causing a delay in hardening of the concrete, the average added mole number is preferably 115 or more, more preferably 117 or more, and further preferably 120 or more. Further, from the viewpoint of polymerizability and fluidity imparting property, n2 is preferably 140 or less, and more preferably 130 or less.

  The monomer (B2) is the same compound as the monomer (A2). This monomer (B2) is an ethylenically unsaturated monocarboxylic acid or a salt thereof, or an ethylenically unsaturated dicarboxylic acid, an acid anhydride thereof, or a salt thereof. For example, acrylic acid, methacrylic acid, crotonic acid Or alkali metal salts thereof, or ammonium salts which may have a substituent. Examples of the ammonium salt which may have a substituent include substituted alkyl ammonium salts such as ammonium salt, alkyl ammonium salt, and hydroxyethyl ammonium salt.

The monomer (B3) is an alkyl, alkenyl or hydroxyalkyl ester monomer of an ethylenically unsaturated monocarboxylic acid, for example, a linear or branched alkyl (meth) acrylic acid ester having 1 to 8 carbon atoms, A linear or branched alkenyl (meth) acrylate ester having 2 to 8 carbon atoms and a hydroxyalkyl (meth) acrylate ester having 2 to 6 carbon atoms can be used. Here, as R ^<7b > in general formula (B3), the thing of a C1-C4 alkyl group is more preferable at the point which the solubility to the water of the polymer obtained is good, and a methyl group is especially preferable. However, the linear and branched forms are not limited.

  The ratio of the monomer (B1) unit, the monomer (B2) unit, and the monomer (B3) unit constituting the component (B) is 0.1 to 50 mol% of the monomer (B1) The range of 0.1 to 50 mol% of the body (B2) and 50 to 90 mol% of the monomer (B3) is excellent in fluid retention, and further 5 to 40 mol% of the monomer (B1) and monomer (B2). ) In the range of 5-40 mol% and monomer (B3) 50-90 mol%, there is almost no decrease in fluidity, and there is a good balance between initial fluidity and fluidity retention. It is extremely excellent in that the amount used can be reduced.

  Moreover, you may manufacture (B) component using another copolymerizable monomer within the range which does not impair the effect of this invention. Examples of such monomers include acrylonitrile, methallyl sulfonic acid, acrylamide, methacrylamide, styrene, styrene sulfonic acid, and the like. More particularly, mention may be made of alkyl, alkenyl or hydroxyalkyl ester monomers of ethylenically unsaturated dicarboxylic acids. Specifically, a maleic acid diester, a fumaric acid diester, an itaconic acid diester, or a citraconic acid diester having 1 to 18 carbon atoms, or a linear or branched alkyl alkenyl maleic acid having 1 to 18 carbon atoms Diesters, fumaric acid diesters, itaconic acid diesters, or citraconic acid diesters can also be used. Also in this case, the linear and branched forms are not limited. Examples of other constituent monomers include acrylamide, vinyl acetate, styrene, vinyl chloride and the like. Further, as other constituent monomers, as unsaturated dicarboxylic acid monomers, maleic acid, itaconic acid, citraconic acid, fumaric acid, or alkali metal salts, alkaline earth metal salts, and substituents thereof. An ammonium salt which may be present can be used. Examples of the ammonium salt which may have a substituent include substituted alkyl ammonium salts such as ammonium salt, alkyl ammonium salt, and hydroxyethyl ammonium salt.

  (B) A component can be manufactured by a well-known method. Examples thereof include solution polymerization methods described in JP-A-62-1119147 and JP-A-62-78137. That is, it is produced by polymerizing the monomer (B1), the monomer (B2) and the monomer (B3) in a suitable solvent in the above ratio.

  Examples of the solvent used in the solution polymerization method include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, benzene, toluene, xylene, cyclohexane, n-hexane, ethyl acetate, acetone, and methyl ethyl ketone. In consideration of handling and reaction equipment, water and methyl alcohol, ethyl alcohol, and isopropyl alcohol are preferable.

  As an aqueous polymerization initiator, persulfuric acid ammonium salt or alkali metal salt or hydrogen peroxide, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis (2-methylpropionamide) Water-soluble azo compounds such as dihydrate are used. For solution polymerization using a non-aqueous solvent, peroxides such as benzoyl peroxide and lauroyl peroxide, aliphatic azo compounds such as azobisisobutyronitrile, and the like are used.

  Moreover, accelerators, such as sodium hydrogen sulfite and an amine compound, can also be used in combination with a polymerization initiator. Furthermore, for the purpose of adjusting the molecular weight, chain transfer agents such as 2-mercaptoethanol, mercaptoacetic acid, 1-mercaptoglycerin, mercaptosuccinic acid and alkyl mercaptan can be used in combination.

  The weight average molecular weight (gel permeation chromatography method / polyethylene glycol equivalent) of the component (B) is preferably in the range of 8,000 to 1,000,000, and more preferably 10,000 to 300,000. When the molecular weight is too large, the fluidity imparting property is lowered, and when the molecular weight is too small, the fluidity retaining property tends to be lowered.

<(C) component>
The component (C) is polyethylene glycol having a weight average molecular weight of 1,000 to 90,000, and the weight average molecular weight is preferably 50,000 to 90,000 from the viewpoint of fluid retention performance. This weight average molecular weight is measured by gel permeation chromatography.

  Component (C) of the present invention is a component that contributes to the expression of fluidity retention in the presence of component (A) and component (B), and the amount of component (A) and component (B) used is the initial fluidity. Even when the amount is small enough not to affect the flow, good fluidity is exhibited by using the component (C).

<Admixture for hydraulic composition>
The hydraulic composition admixture in the present invention is generally used as one agent by combining three types of the component (A), the component (B) and the component (C). Can be used separately.

  In the admixture for hydraulic composition of the present invention, the weight ratio of the component (A) to the component (C) is [(C) / (A)] = 0.1 from the viewpoint of initial fluidity and fluid retention performance. It is preferable that it is -1, More preferably, it is 0.15-0.8, More preferably, it is 0.2-0.6.

  In the admixture for hydraulic composition of the present invention, from the viewpoint of initial fluidity and fluid retention performance, the weight ratio of the sum of the components (A) and (B) and the component (C) is [( C) / {(A) + (B)}] = 0.1 to 0.85, more preferably 0.15 to 0.7, and still more preferably 0.2 to 0.5. .

  The amount of the admixture for hydraulic composition of the present invention added to the hydraulic composition is preferably 0.1 to 3.5% by weight in terms of solid content with respect to the hydraulic powder (cement etc.). More preferred is ˜2% by weight.

  Furthermore, the admixture for hydraulic composition of the present invention may contain a high-performance water reducing agent. An example of a high-performance water reducing agent is naphthalene (for example, Mighty 150: manufactured by Kao Corporation), melamine (for example, Mighty 150V-2: manufactured by Kao Corporation), aminosulfonic acid (for example, Palic FP: Fujisawa) Chemical Co., Ltd.), (A) component, and polycarboxylic acid-based compounds (for example, Mighty 2000WHZ: manufactured by Kao Corporation) made of compounds not corresponding to the component (B).

  The admixture for hydraulic composition can be used in combination with known additives (materials). For example, AE agent, AE water reducing agent, fluidizing agent, retarding agent, early strengthening agent, accelerator, foaming agent, foaming agent, antifoaming agent, thickener, waterproofing agent, antifoaming agent, water retention agent, self-leveling agent , Waterproofing agent, rust-preventing agent, crack reducing agent, silica sand, blast furnace slag, fly ash, silica fume and the like.

  Furthermore, the admixture for hydraulic composition of the present invention is added to hydraulic powder, especially cement paste using cement, mortar, concrete, etc., and the content thereof is not limited.

  The hydraulic powder used in the hydraulic composition that is the target of the admixture of the present invention is a powder having physical properties that is cured by a hydration reaction, and examples thereof include cement and gypsum. Preferred are ordinary Portland cement, Belite cement, moderate heat cement, early strong cement, super early strong cement, sulfuric acid resistant cement, etc., and blast furnace slag, fly ash, silica fume, stone powder (calcium carbonate powder), etc. May be added. In addition, the hydraulic composition finally obtained by adding sand, sand and gravel as aggregates to these powders is generally called mortar, concrete, etc., respectively. The admixture of the present invention is not only for the ready-mixed concrete and concrete vibration product fields, but also for self-leveling, for refractories, for plaster, for gypsum slurry, for lightweight or heavy concrete, for AE, for repairing, for prepacked, for trayy, It is useful in any field of various concrete such as grout, ground improvement, and cold.

  The hydraulic composition has a water / hydraulic powder ratio [weight percentage (% by weight) of water and hydraulic powder in the slurry, usually abbreviated as W / P. Abbreviated as / C. ] 65% by weight or less, further 10 to 60% by weight, further 12 to 57% by weight, further 15 to 55% by weight, and further 20 to 55% by weight. Furthermore, the effect of the admixture of the present invention is remarkably exhibited even when the unit water content is as low as 40% by weight or less.

<Blending ingredients>
(1) (A) Component A-1: Methanol EO (23) Aqueous solution (solid content) of copolymer Na salt (weight average molecular weight 51000) of methacrylic acid monoester / methacrylic acid = 30/70 (molar ratio) 40% aqueous solution adjusted to a solid content of 23% using ion-exchanged water) (EO is an abbreviation for ethylene oxide, the number in parentheses is the average number of moles added, and so on.)
A-2: Methanol EO (23) obtained by the following production example Methacrylic acid monoester / 2-hydroxyethyl methacrylate monophosphate / 2-hydroxyethyl methacrylate diphosphate = 50/35/15 (molar ratio) An aqueous solution of a copolymer Na salt (weight average molecular weight 35000) (an aqueous solution having a solid content of 35% was adjusted to a solid content of 23% using ion-exchanged water)

Production example (production of aqueous copolymer solution for A-2)
A glass reaction vessel (four-necked flask) equipped with a stirrer was charged with 423 g of water, purged with nitrogen while stirring, and heated to 80 ° C. in a nitrogen atmosphere. ω-Methoxypolyethyleneglycol monomethacrylate (average added mole number of ethylene oxide 23) 407 g (effective part 60.8%, moisture 35%), mono (2-hydroxyethyl) methacrylate and di-[( 2-Hydroxyethyl) methacrylic acid] ester mixture 65.0 g of phosphoric acid ester (A) and 4.1 g of 3-mercaptopropionic acid and 7.6 g of ammonium persulfate were dissolved in 30.4 g of water. Two of these solutions were dropped into the reaction vessel over 1.5 hours. Thereafter, aging was performed for 1 hour, and a solution obtained by dissolving 1.7 g of ammonium persulfate in 6.7 g of water was added dropwise over 30 minutes, followed by aging for 1.5 hours. The temperature of the reaction system during this series was kept at 80 ° C. The mixture was neutralized with 63.5 g of a 30% aqueous sodium hydroxide solution after completion of aging to obtain a copolymer for A-2 (solid content 35%).

In addition, the phosphoric acid ester product (A) used in this production example was obtained by the following production method. A reaction vessel was charged with 200 g of 2-hydroxyethyl methacrylate and 36.0 g of 85% phosphoric acid (H ₃ PO ₄ ), and 89.1 g of phosphorus pentoxide (anhydrous phosphoric acid) (P ₂ O ₅ ) at a temperature of 60 The solution was gradually added while cooling so as not to exceed ° C. After completion, the reaction temperature was set to 80 ° C., the reaction was performed for 6 hours, and after cooling, a phosphoric acid ester (A) was obtained.

(2) Component (B) B-1: Methanol EO (120) Methacrylic acid monoester / Methyl acrylate / Methacrylic acid = 10/70/20 (molar ratio) copolymer Na salt (weight average molecular weight 81000 ) Aqueous solution (an aqueous solution with a solid content of 40% adjusted to a solid content of 23% with ion-exchanged water)

(3) Component (C) · C-1: Polyethylene glycol (weight average molecular weight 1,000)
C-2: Polyethylene glycol (weight average molecular weight 10,000)
C-3: Polyethylene glycol (weight average molecular weight 70,000)
C-4: Polyethylene glycol (weight average molecular weight 90,000)
C-5: polyethylene glycol (weight average molecular weight 100,000)

<Manufacture and evaluation of concrete>
The materials were weighed so that the mixing amount of the concrete was 30 liters with the two blends shown in Table 1, and concrete was prepared using a forced biaxial mixer. As for kneading, after adding coarse aggregate, 1/2 weight of fine aggregate, cement, and 1/2 weight of fine aggregate were charged, and empty kneading was carried out for 10 seconds. Then, the kneading water containing the admixture for hydraulic composition was added, discharged after stirring for 90 seconds, and the fluidity (slump value) of the concrete was measured by JIS A1011 method (immediately after). At this time, the amount of air in the concrete was adjusted to 4 to 5%. Further, the concrete was allowed to stand for 60 minutes with a kneaded plate, and the slump value and the amount of air were measured (after 60 minutes). The evaluation results for Formulation 1 and Formulation 2 are shown in Table 2 and Table 3, respectively.

The components in Table 1 are as follows.
a) Fine aggregate (S): Joyo mountain sand FM = 2.67 Density: 2.55 g / cm ³
b) Coarse aggregate (G1): Torigata mountain sand Limestone crush 2010 FM = 6.92 Density: 2.72 g / cm ³
c) Coarse aggregate (G2): Torigata mountain sand Limestone crushed stone 1005 FM = 5.87 Density: 2.72 g / cm ³
d) Cement (C1): Ordinary Portland cement (manufactured by Taiheiyo Cement / Sumitomo Osaka Cement = 50/50) Density: 3.16 g / cm ³
e) Cement (C2): Medium heat cement (manufactured by Taiheiyo Cement) Density: 3.21 g / cm ³

  In the table, the amount of admixture added is the weight percent of the solid content relative to the cement weight for each component.

  From the above results, it is difficult to maintain fluidity until after 60 minutes when the component (A) or component (B) is used alone, or when the component (A) and component (B) are used in combination. By using three types of (A) component, (B) component, and (C) component, high fluidity retention can be expressed.

  Furthermore, the product of the present invention can exhibit initial fluidity as compared with the case where only the component (A) or the component (B) is used.

  Therefore, if the admixture for hydraulic composition of the present invention is added to the hydraulic composition, the initial fluidity is easily expressed, and further, since there is little slump change over a long period of time, there are a variety of such as at high temperatures in summer. (Placement etc.) can be met.

Claims (4)

An admixture for a hydraulic composition containing the following components (A) to (C).
<(A) component>
In the copolymer (A-1) obtained by polymerizing the monomer represented by the following general formula (A1) and the monomer represented by the following general formula (A2), and the following general formula (A1) And a copolymer (A-2) obtained by polymerizing a monomer represented by the following general formula (A3) and a monomer represented by the following general formula (A4). One or more copolymers selected from the group

[Wherein, R ^1a represents a hydrogen atom and R ^2a represents a methyl group. AO is an oxyalkylene group having 2 carbon atoms, n1 is the average added mole number of AO, and represents a number of 8-25. X ¹ represents an alkyl group having 1 carbon atom. ]

[Wherein, R ^3a represents a hydrogen atom, R ^4a represents a methyl group, and R ^5a represents a hydrogen atom. M ^1a represents a hydrogen atom, a monovalent metal, or an ammonium group which may have a substituent. ]

[Wherein, R ^6a represents a hydrogen atom or a methyl group. R ^7a represents an alkylene group having 2 to 6 carbon atoms. M ^2a and M ^3a each independently represent a hydrogen atom, an alkali metal, or an alkaline earth metal (1/2 atom). m1 is the average added mole number of OR ^7a and represents a number of 1 to 30. ]

[Wherein, R ^8a and R ^10a each represent a hydrogen atom or a methyl group. R ^9a and R ^11a each independently represents an alkylene group having 2 to 6 carbon atoms. M ^4a represents a hydrogen atom, an alkali metal or an alkaline earth metal (1/2 atom). m2 and m3 are the average added mole numbers of OR ^9a and OR ^11a , respectively, and each independently represents a number of 1 to 30. ]
<(B) component>
A monomer represented by the following general formula (B1) [hereinafter referred to as monomer (B1)] , a monomer represented by the following general formula (B2) [hereinafter referred to as monomer (B2)], and The monomer represented by the following general formula (B3) [hereinafter referred to as the monomer (B3)] is 5 to 40 mol% monomer (B1), 5 to 40 mol% monomer (B2), and Copolymer obtained by polymerizing monomer (B3) at a ratio of 50 to 90 mol%

[Wherein, R ^1b represents a hydrogen atom, and R ^2b represents a methyl group. A′O is an oxyalkylene group having 2 carbon atoms, n2 is the average number of moles added of A′O, and represents a number of 110 to 150. X ² represents an alkyl group having 1 carbon atom. ]

[Wherein, R ^3b represents a hydrogen atom, R ^4b represents a methyl group, and R ^5b represents a hydrogen atom. M ^1b represents a hydrogen atom, a monovalent metal, or an ammonium group which may have a substituent. ]

[R ^6b represents a hydrogen atom or a methyl group. R ^7b represents a C 1-8 alkyl group, a C 2-8 alkenyl group, or a C 2-6 hydroxy group-containing alkyl group. ]
<(C) component>
Polyethylene glycol having a weight average molecular weight of 1,000 to 90,000   The admixture for hydraulic composition according to claim 1, wherein the weight ratio of the component (A) to the component (C) is [(C) / (A)] = 0.1-1.   The weight ratio of the sum of the components (A) and (B) and the component (C) is [(C) / {(A) + (B)}] = 0.15 to 0.85. The admixture for hydraulic compositions according to 1 or 2.   The weight average molecular weight of (C) component is 50,000-90,000, The admixture for hydraulic compositions in any one of Claims 1-3.