JP2020083747A - Water-reducing composition, hydraulic composition, and method for producing the same - Google Patents

Abstract

To provide a water-reducing composition which contains a polycarboxylic acid-based water reducing agent, water-soluble cellulose ether, gums, and a defoamer, and has storage stability improved.SOLUTION: A water-reducing composition includes (A) a water reducing agent containing a polycarboxylic acid-based water reducing agent and a naphthalene-based water reducing agent, (B) water-soluble cellulose ether, (C) gums, and (D) a defoamer. The ratio between a solid content mass of the polycarboxylic acid-based water reducing agent and a solid content mass of the naphthalene-based water reducing agent is preferably 1:99 to 80:20.SELECTED DRAWING: None

Description

The present invention relates to a water reducing composition, a hydraulic composition, and a method for producing the same.

The hydraulic composition is a composition containing at least a hydraulic material such as cement, an aggregate such as fine aggregate and/or coarse aggregate, and water, and is an aggregate of inorganic materials having different specific gravities, particle shapes, and particle sizes. Therefore, the composition is likely to cause material separation. Therefore, an attempt has been made to improve the viscosity of a hydraulic composition by adding a water-soluble polymer as a thickener.

For example, water-soluble cellulose ether has a pH of cement of 12 or more and is a strong alkali, and there are many calcium ions originating from the components of the cement, and the water-soluble polymer is under severe conditions. It is a few nonionic water-soluble polymer that can be thickened even in a hydraulic composition.

However, since water-soluble cellulose ethers are generally used in powder form, they are inferior in handling as compared with other liquid admixtures, and form mamako upon addition, or scatter when a trace amount is added. Then, there is a problem that it becomes difficult to add a desired amount.

In order to solve these problems, a water reducing agent composition (one-pack type water reducing agent) in which a water-soluble cellulose ether, an antifoaming agent, gums and a water reducing agent are mixed in advance has been proposed (for example, JP-A-2016-056081). Publication (Patent Document 1)).

JP, 2016-056081, A

However, in Patent Document 1, although an attempt is made to improve the storage stability of the water reducing agent composition by using gums, depending on the solid content concentration and Na ⁺ ion concentration of the polycarboxylic acid water reducing agent, storage stability is improved. There was room for improvement in some cases because it was inferior in sex.

The present invention has been made in view of the above circumstances, and is a water reducing agent composition containing a polycarboxylic acid type water reducing agent, a water-soluble cellulose ether, gums and a defoaming agent, the storage stability of which is improved. It is an object to provide a water reducing agent composition, a hydraulic composition using the same, and a method for producing the same.

The present inventor, as a result of intensive research to solve the above problems, a polycarboxylic acid-based water reducing agent, a water-soluble cellulose ether, gums, a water reducing agent composition containing at least a defoaming agent, By using a naphthalene-based water reducing agent in combination, it is possible to improve the storage stability of the water reducing agent composition even when maintaining a high Na ⁺ ion concentration, and also to maintain the fluidity of the hydraulic composition at a high level. The present invention has been accomplished and the present invention has been accomplished.

That is, the present invention provides the following water reducing agent composition, hydraulic composition, and method for producing the same.
1.
A water reducing agent composition containing (A) a polycarboxylic acid water reducing agent and a naphthalene water reducing agent, (B) a water-soluble cellulose ether, (C) gums, and (D) a defoaming agent.
2.
1. The water reducing agent according to 1, wherein the ratio SC _pc :SC _np of the solid content mass (SC _pc ) of the polycarboxylic acid type water reducing agent and the solid content mass (SC _np ) of the naphthalene type water reducing agent is 1:99 to 80:20. Composition.
3.
The water reducing agent composition according to 1 or 2, wherein the component (A) has a Na ⁺ ion concentration of 8,500 ppm or more.
4.
The water-reducing agent composition according to any one of 1 to 3, wherein the water-soluble cellulose ether is one kind or two or more kinds selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose and hydroxyalkylalkyl cellulose.
5.
5. The water reducing composition according to any one of 1 to 4, wherein the gums are one kind or two or more kinds selected from the group consisting of diutan gum, welan gum, xanthan gum and gellan gum.
6.
A hydraulic composition comprising the water reducing agent composition according to any one of 1 to 5, a hydraulic material, and water.
7.
A method for producing a hydraulic composition, which comprises a step of mixing the water reducing agent composition according to any one of 1 to 5, a hydraulic material, and water.

According to the present invention, by using a polycarboxylic acid water reducing agent and a naphthalene water reducing agent in combination, the storage stability of the water reducing agent composition is improved, and a bleeding suppressing effect when used in a hydraulic composition is expected. It Furthermore, since addition of a naphthalene-based water reducing agent does not cause aggregation with the water-soluble cellulose ether, a water reducing effect can be expected and a fluid hydraulic composition can be obtained.

[Water reducing composition]
The constitution of the water reducing agent composition according to the present invention will be described below.
The water reducing agent composition according to the present invention,
(A) a water reducing agent containing a polycarboxylic acid water reducing agent and a naphthalene water reducing agent,
(B) Water-soluble cellulose ether,
(C) gums,
(D) It contains an antifoaming agent.
The water reducing agent composition is a composition (one-pack type water reducing agent) for a hydraulic composition containing at least a water reducing agent, a water-soluble cellulose ether, gums and an antifoaming agent.

(Component (A))
The component (A) is a water reducing agent containing a polycarboxylic acid type water reducing agent and a naphthalene type water reducing agent, and preferably comprises a polycarboxylic acid type water reducing agent and a naphthalene type water reducing agent. The water reducing agent here is a chemical admixture that reduces the amount of unit water required to obtain a predetermined slump flow, and is called a so-called high performance water reducing agent, AE water reducing agent, or high performance AE water reducing agent. All of them are included, and any of these is preferable.

Specific examples of the polycarboxylic acid-based water reducing agent include polycarboxylic acid ether-based compounds, composites of polycarboxylic acid ether-based compounds and crosslinked polymers, composites of polycarboxylic acid ether-based compounds and oriented polymers, polycarboxylic acid ether-based compounds. Compounds and highly modified polymer composites, polyether carboxylic acid polymer compounds, maleic acid copolymers, maleic acid ester copolymers, maleic acid derivative copolymers, carboxyl group-containing polyether compounds, terminal sulfone groups Examples thereof include polycarboxylic acid group-containing multi-component polymers, polycarboxylic acid-based graft copolymers, polycarboxylic acid ether-based polymers and the like.

As the polycarboxylic acid-based water reducing agent, commercially available products can be used. For example, Chupol HP-11 (manufactured by Takemoto Yushi Co., Ltd.), Master Glenium SP8SV X2 (manufactured by BASF Japan Ltd.) and the like can be mentioned. The property is preferably liquid. If necessary, a commercially available polycarboxylic acid water reducing agent may be appropriately diluted with water.
Two or more polycarboxylic acid water reducing agents may be used in combination.

Specific examples of the naphthalene-based water reducing agent include those containing naphthalene sulfonate or a derivative thereof as a main component. As the naphthalene-based water reducing agent, a commercially available one can be used, and examples thereof include Mighty 150 (manufactured by Kao Corporation). The property is preferably liquid. If necessary, a commercially available naphthalene-based water reducing agent may be appropriately diluted with water.
Two or more naphthalene-based water reducing agents may be used in combination.

The solid content concentration in the mixture of the polycarboxylic acid water reducing agent and the naphthalene water reducing agent (that is, the water reducing agent (A)) is preferably 10% by mass or more from the viewpoint of storage stability after liquefaction (uniform dispersion). %, more preferably 10 to 50% by mass, further preferably 12.5 to 30% by mass, and particularly preferably 13 to 20% by mass. When the solid content concentration of the component (A) is less than 10% by mass or more than 50% by mass, the storage stability after one liquefaction (uniform dispersion) may decrease.

The solid content concentration of the water reducing agent can be measured as follows.
First, a predetermined amount (for example, about 5 g) of a water reducing agent is placed in a weighing bottle (for example, a bottle volume of 16 ml), and its mass, that is, the mass (g) of the water reducing agent before drying is measured. Then, it is dried in a drier at 105° C. to a constant weight, and the mass (g) of the dried water reducing agent is measured. The solid content concentration is calculated by the following calculation formula using the measured masses of the water reducing agent before and after drying (hereinafter the same).
Solid content concentration (mass %)={mass of water reducing agent after drying (g)/mass of water reducing agent before drying (g)}×100

The ratio (mass ratio; SC _pc :SC _np ) of the solid content mass (SC _pc ) of the polycarboxylic acid water reducing agent and the solid content mass (SC _np ) of the naphthalene water reducing agent in the component (A) is one liquid (uniform). From the viewpoint of storage stability after dispersion, it is preferably 1:99 to 80:20, more preferably 5:95 to 70:30, and further preferably 10:90 to 55:45. If the amount is out of the above range, the storage stability after liquefaction (uniform dispersion) may decrease.

The Na ⁺ ion concentration in the mixture of the polycarboxylic acid water reducing agent and the naphthalene water reducing agent (that is, the water reducing agent (A)) is preferably 8,500 ppm from the viewpoint of storage stability after liquefaction (uniform dispersion). The above is more preferably 9,000 to 30,000 ppm, still more preferably 9,500 to 2,500 ppm, and particularly preferably 10,000 to 20,000 ppm. If the Na ⁺ ion concentration in the component (A) is less than 8,500 ppm, the storage stability after liquefaction (uniform dispersion) may decrease.
The Na ⁺ ion concentration of the water reducing agent can be measured by an ion chromatography method (hereinafter the same). Details will be described in Examples.

In producing the water reducing agent composition of the present invention, it is preferable to use a polycarboxylic acid water reducing agent and a naphthalene water reducing agent under the following conditions.

That is, the solid content concentration of the polycarboxylic acid-based water reducing agent is preferably 10 to 25% by mass, more preferably 12 to 24.5% by mass, from the viewpoint of the economical amount or the amount added during the production of the hydraulic composition. More preferably, it is 13 to 20 mass %.

The Na ⁺ ion concentration of the polycarboxylic acid-based water reducing agent is preferably 8,500 ppm or more, more preferably 9,000 to 18,000 ppm, and further preferably from the viewpoint of storage stability after liquefaction (uniform dispersion). It is preferably 9,000 to 16,000 ppm, particularly preferably 9,000 to 12,000 ppm.

The water reduction rate of the polycarboxylic acid water reducing agent is preferably 18% or more, and more preferably 19 to 30%, from the viewpoint of economy or the amount added in the production of the hydraulic composition.
The water reduction rate of the water reducing agent can be calculated from the unit water amounts of the standard concrete and the test concrete defined in JIS A6204 (hereinafter the same).

The solid content concentration of the naphthalene-based water reducing agent is preferably 10 to 50% by mass, more preferably 10 to 40% by mass, and still more preferably 10 to 20 from the viewpoint of economy or the amount added at the time of production of the hydraulic composition. It is% by mass.

The Na ⁺ ion concentration of the naphthalene-based water reducing agent is preferably 8,500 ppm or more, more preferably 9,000 to 40,000 ppm, further preferably from the viewpoint of storage stability after liquefaction (uniform dispersion). It is 10,000 to 35,000 ppm, particularly preferably 10,000 to 20,000 ppm.

From the viewpoint of the fluidity of the hydraulic composition, the water reduction rate of the naphthalene-based water reducing agent is preferably 10% or more, more preferably 12 to 30%.

Further, the absolute value of the difference between the Na ⁺ ion concentration of the polycarboxylic acid type water reducing agent and the Na ⁺ ion concentration of the naphthalene type water reducing agent is preferably 1, from the viewpoint of storage stability after liquefaction (uniform dispersion). 000 ppm or more, more preferably 1,500 to 30,000 ppm, still more preferably 1,750 to 25,000 ppm, and particularly preferably 2,000 to 10,000 ppm.
Further, from the viewpoint of storage stability after one-liquefaction (uniform dispersion), the Na ⁺ ion concentration of the naphthalene-based water reducing agent is preferably higher than the Na ⁺ ion concentration of the polycarboxylic acid-based water reducing agent.

In the water reducing agent composition of the present invention, (A) the water reducing agent (the total mass of the polycarboxylic acid type water reducing agent and the naphthalene type water reducing agent) becomes a reference amount (for example, 100 parts by mass), and a predetermined ratio with respect to this water reducing agent. Add water-soluble cellulose ether, gums and defoamer at.

((B) component)
The water-soluble cellulose ether is preferably a nonionic one, such as alkyl cellulose such as methyl cellulose; hydroxyalkyl cellulose such as hydroxyethyl cellulose and hydroxypropyl cellulose; and hydroxyalkyl alkyl cellulose such as hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose and hydroxyethyl ethyl cellulose. Is mentioned.

In the above-mentioned alkyl cellulose, in methyl cellulose, the degree of substitution (DS) of the methoxy group is preferably 1.0 to 2.2, more preferably 1.2 to 2.0. The degree of substitution (DS) of the alkoxy group in the alkyl cellulose can be obtained by converting the value that can be measured by the method for analyzing the degree of substitution of methyl cellulose of the 17th revised Japanese Pharmacopoeia.

Among the above-mentioned hydroxyalkyl cellulose, in hydroxyethyl cellulose, the substitution number of moles (MS) of hydroxyethoxy group is preferably 0.3 to 3.0, more preferably 0.5 to 2.8. The number of moles (MS) of hydroxypropoxy group substitution is preferably 0.1 to 3.3, and more preferably 0.3 to 3.0. The number of moles of hydroxyalkoxy groups substituted in the hydroxyalkyl cellulose can be determined by converting a value that can be measured by the method for analyzing the degree of substitution of hydroxypropylcellulose of the 17th revised Japanese Pharmacopoeia.

Of the above hydroxyalkylalkyl celluloses, in hydroxypropylmethyl cellulose, the degree of substitution (DS) of the methoxy group is preferably 1.0 to 2.2, more preferably 1.3 to 1.9, the substitution mole of the hydroxypropoxy group. The number (MS) is preferably 0.1 to 0.6, more preferably 0.1 to 0.5. In the hydroxyethylmethyl cellulose, the degree of substitution (DS) of the methoxy group is preferably 1.0 to 2.2, more preferably 1.3 to 1.9, and the number of substitution moles (MS) of the hydroxyethoxy group is It is preferably 0.1 to 0.6, more preferably 0.15 to 0.4. In the hydroxyethylethyl cellulose, the degree of substitution (DS) of the ethoxy group is preferably 1.0 to 2.2, more preferably 1.2 to 2.0, and the number of substitution moles (MS) of the hydroxyethoxy group is It is preferably 0.05 to 0.6, more preferably 0.1 to 0.5. In addition, the substitution degree of the alkoxy group and the substitution mole number of the hydroxyalkoxy group in the hydroxyalkylalkylcellulose are converted into values that can be measured by the substitution degree analysis method for hypromellose (hydroxypropylmethylcellulose) described in the 17th revised Japanese Pharmacopoeia. You can ask.

In addition, DS of the alkoxy group in alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkylalkyl cellulose represents the degree of substitution (degree of substitution), and refers to the average number of methoxy groups per unit of anhydrous glucose.
The MS of the hydroxyalkoxy group in alkylcellulose, hydroxyalkylcellulose, and hydroxyalkylalkylcellulose represents the number of moles of substitution (mol substitution), which is the average number of moles of hydroxyalkoxy groups per mole of anhydrous glucose.

As the water-soluble cellulose ether, hydroxyalkylalkyl celluloses such as hydroxypropylmethyl cellulose and hydroxyethylmethyl cellulose are preferable among those exemplified above from the viewpoint of imparting material separation resistance to the hydraulic composition.

The viscosity of a 1% by mass aqueous solution of water-soluble cellulose ether at 20° C. is preferably 30 to 30,000 mPa·s, more preferably 300 to 25,000 mPa·s, from the viewpoint of imparting a predetermined viscosity to the hydraulic composition. It is more preferably 500 to 20,000 mPa·s, and particularly preferably 500 to 3,000 mPa·s.
The viscosity of a 1% by mass aqueous solution of water-soluble cellulose ether at 20°C can be measured using a B-type viscometer under a measurement condition of 12 rpm.

The amount of the water-soluble cellulose ether added is 100 parts by mass of the total mass of the polycarboxylic acid-based water reducing agent and the naphthalene-based water reducing agent (that is, the component (A)) from the viewpoint of imparting a predetermined viscosity to the hydraulic composition. , Preferably 0.1 to 5 parts by mass, more preferably 0.4 to 3 parts by mass.

The water-soluble cellulose ethers may be used alone or in combination of two or more. Further, as the water-soluble cellulose ether, a commercially available one may be used, or one produced by a known method may be used.

((C) component)
Examples of gums include diutan gum, welan gum, xanthan gum, gellan gum and the like.

Dieuthan gum is composed of D-glucose, D-glucuronic acid, D-glucose and L-rhamnose, and two L-rhamnose.
Welan gum has a structure in which an L-rhamnose or L-mannose side chain is bonded to a main chain to which D-glucose, D-glucuronic acid, and L-rhamnose are bonded at a ratio of 2:2:1.
Like cellulose, xanthan gum has a main chain of β-1,4 bond of D-glucose, and a side chain composed of two mannose and one glucuronic acid.
Gellan gum is a heteropolysaccharide having 4 sugars in which D-glucose, D-glucuronic acid and L-rhamnose are combined at a ratio of 2:1:1 as a repeating unit.
By using gums, it is possible to improve the apparent viscosity of the water-reducing agent, improve the dispersion state of the water-soluble cellulose ether in the water-reducing agent composition, and improve the storage stability after liquefaction (uniform dispersion). it can.

The amount of gums added is such that, in the case of diutan gum, polycarboxylic acid-based water-reducing agents are used from the viewpoint of improving the dispersion state of the water-soluble cellulose ether in the water-reducing agent composition and improving the storage stability after liquefaction (dispersion). With respect to 100 parts by mass of the total mass of the agent and the naphthalene-based water reducing agent (that is, the component (A)), preferably 0.005 to 2 parts by mass, more preferably 0.01 to 1 part by mass, still more preferably 0. It is 1 to 0.8 parts by mass. Further, in the case of welan gum, xanthan gum, and gellan gum, preferably 0.01 to 20 parts by mass, more preferably 0.01 to 20 parts by mass, relative to 100 parts by mass of the total mass of the polycarboxylic acid type water reducing agent and the naphthalene type water reducing agent (that is, the component (A)). The amount is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 8 parts by mass.

The gums may be used alone or in combination of two or more. As the gums, commercially available gums can be used.

((D) component)
Examples of the defoaming agent include an oxyalkylene defoaming agent, a silicone defoaming agent, an alcohol defoaming agent, a mineral oil defoaming agent, a fatty acid defoaming agent, and a fatty acid ester defoaming agent.

Specific examples of the oxyalkylene defoaming agent include polyoxyalkylenes such as (poly)oxyethylene (poly)oxypropylene adducts; diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene poly. (Poly)oxyalkylene alkyl ethers such as oxypropylene 2-ethylhexyl ether, higher alcohols having 8 or more carbon atoms and oxyethyleneoxypropylene adducts to secondary alcohols having 12 to 14 carbon atoms; polyoxypropylene phenyl ether, poly (Poly)oxyalkylene(alkyl)aryl ethers such as oxyethylene nonylphenyl ether; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne- Acetylene ethers obtained by addition-polymerizing alkylene oxides to acetylene alcohols such as 2,5-diol and 3-methyl-1-butyn-3-ol; diethylene glycol oleate, diethylene glycol lauryl ester, ethylene glycol distearate, poly (Poly)oxyalkylene fatty acid esters such as oxyalkylene oleate; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan trioleate (poly)oxyalkylene sorbitan fatty acid esters; polyoxypropylene methyl ether sulfate Sodium, polyoxyethylene dodecylphenol ether sodium sulfate and other (poly)oxyalkylene alkyl (aryl) ether sulfate ester salts; (poly)oxyethylene stearyl phosphate ester and other (poly)oxyalkylene alkyl phosphate esters; polyoxy (Poly)oxyalkylene alkyl amines such as ethylene lauryl amine; and polyoxyalkylene amide.

Specific examples of the silicone defoaming agent include dimethyl silicone oil, silicone paste, silicone emulsion, organically modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), fluorosilicone oil and the like.

Specific examples of the alcohol-based defoaming agent include octyl alcohol, 2-ethylhexyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like.
Specific examples of the mineral oil type defoaming agent include kerosene and liquid paraffin.
Specific examples of the fatty acid-based defoaming agent include oleic acid, stearic acid, and alkylene oxide adducts thereof.
Specific examples of the fatty acid ester antifoaming agent include glycerin monoricinolate, alkenylsuccinic acid derivatives, sorbitol monolaurate, sorbitol trioleate, and natural wax.
Among these, the oxyalkylene-based defoaming agent is preferable from the viewpoint of efficiently defoaming the entrained air of the water-soluble cellulose ether and gums and improving the storage stability after liquefaction (uniform dispersion).

The amount of the defoaming agent added is a polycarboxylic acid-based water reducing agent from the viewpoint of efficiently defoaming the entrained air of water-soluble cellulose ethers and gums and improving the storage stability after liquefaction (uniform dispersion). It is preferably 0.001 to 16 parts by mass, and more preferably 0.002 to 10 parts by mass, based on 100 parts by mass of the total mass of the naphthalene-based water reducing agent (that is, the component (A)).

The antifoaming agents may be used alone or in combination of two or more kinds. A commercially available antifoaming agent can be used.

The water reducing agent composition of the present invention has improved storage stability. For example, the sedimentation volume after standing for 72 hours immediately after one liquefaction (uniform dispersion) is 65% by volume or more. Further, according to the present invention, it is also possible to set the sedimentation volume after the liquefaction (uniform dispersion) of the water reducing agent composition for 168 hours to 50% by volume or more.

Here, the sedimentation volume means that a predetermined amount (for example, 100 ml) of the water reducing agent composition immediately after being liquefied (uniformly dispersed) (immediately after mixing) is poured into a graduated cylinder having a predetermined outer diameter (for example, 32 mm) and having a room temperature ( It means the volume ratio (suspension maintenance ratio) of the suspension layer (water reducing agent composition layer) to the entire liquid, which is observed when it is allowed to stand at 20±3° C. for a certain period of time. The amount of the water reducing agent composition immediately after liquefaction (homogeneous dispersion) (immediately after mixing) and the size (outer diameter and height) of the graduated cylinder to be used are the suspension layer (reduction water) in the whole liquid during the above observation. There is no particular limitation as long as the height of the agent composition layer) (that is, the boundary position between the supernatant liquid and the suspension layer in the entire liquid) can be clearly confirmed by visual observation.

The water reducing agent composition of the present invention is produced by a step of obtaining a water reducing agent composition by mixing a polycarboxylic acid type water reducing agent, a naphthalene type water reducing agent, a water-soluble cellulose ether, gums, and an antifoaming agent. can do.

At this time, the order of adding the polycarboxylic acid type water reducing agent, the naphthalene type water reducing agent, the water-soluble cellulose ether, the gums, and the defoaming agent (that is, the order of adding the materials and mixing) is not particularly limited.

Further, the polycarboxylic acid water reducing agent and the naphthalene water reducing agent may be added separately or may be mixed in advance and then added. Further, the polycarboxylic acid water reducing agent and the naphthalene water reducing agent may be added at the same time or either may be added first. For example, while the stirrer of the stirrer described below is rotating, polycarboxylic acid-based water reducing agent, naphthalene-based water reducing agent, water-soluble cellulose ether, gums, defoaming agents are added in any order and mixed. Alternatively, the polycarboxylic acid type water reducing agent and the naphthalene type water reducing agent may be mixed in advance, and the water reducing agent mixture, water-soluble cellulose ether, gums and defoaming agent may be added in any order. Furthermore, either one of a polycarboxylic acid type water reducing agent and a naphthalene type water reducing agent is added, and then a mixture of water-soluble cellulose ether, gums and an antifoaming agent is added in advance for a certain period of time (1 After mixing for about a minute), the remaining water reducing agent may be added and mixed at the end.
Further, the gums may be added in the form of powder or aqueous solution.

The mixing method is not particularly limited, and can be performed using, for example, a stirrer.
The stirrer is a device including a stirrer (rotary blade) that rotates at a high speed, and a container in which the above materials can be mixed by the rotation of the stirrer. For example, a homomixer (HM-310, manufactured by AS ONE), Rotor/stator type mixer such as high speed homomixer (LZB14-HM-1, manufactured by Chuo Rika Co., Ltd.), cylindrical wall rotating mixer such as thin film swirling high speed mixer (Filmix, manufactured by Primix), homogenizer (PH91, manufactured by SMT Corporation) ), etc., or a high-speed stirrer to which those principles are applied. Among these, a rotor-stator type mixer or a cylindrical wall swirling mixer is preferable.

Examples of types of stirrers (rotating blades) in a stirrer include a turbine/stator type, a thin film swivel type (PC wheel), a disper type, and a perforated basket type, but the stirring efficiency and storage stability of the water reducing agent composition From the viewpoint of the property, the turbine-stator type and the thin film rotating type (PC wheel) are preferable.

The peripheral speed of the stirrer in the stirrer is preferably 7 to 30 m/s, more preferably 7 to 15 m/s, from the viewpoint of efficient productivity of the water reducing agent composition.
The peripheral speed of the stirrer is the speed of the fastest part of the stirrer (rotating blade) that rotates in the stirrer (that is, the outermost circumference of the stirrer).

The peripheral speed v (m/s) of the stirrer is calculated by the following formula from the diameter d (mm) of the stirrer and the rotational speed n (rpm (the number of rotations per minute)) of the stirrer.
v=π×d×n/60,000

The mixing time (stirring time) is the time after the target peripheral speed of the stirrer has been reached after all the ingredients such as the water reducing agent, water-soluble cellulose ether, gums, and defoaming agent have been added, or the target peripheral speed of the stirrer. Efficient productivity of the water-reducing agent composition, though not particularly limited, after reaching the speed and after all the ingredients such as the water-reducing agent, water-soluble cellulose ether, gums, and defoaming agent are charged. From the viewpoint, it is preferably 30 seconds or longer, more preferably 1 minute or longer. The upper limit of the mixing time is not particularly limited, but from the viewpoint of efficient productivity of the water reducing agent composition, it is preferably 60 minutes or less, more preferably 10 minutes or less.

[Hydraulic composition and method for producing the same]
The hydraulic composition according to the present invention is characterized by containing the above-described water reducing agent composition of the present invention, a hydraulic substance, and water.
The method for producing a hydraulic composition according to the present invention is characterized by including at least a step of mixing the above-described water reducing agent composition of the present invention, a hydraulic substance, and water.

Concrete applications of the hydraulic composition include concrete, mortar and cement paste.

The hydraulic composition for concrete is preferably a composition containing the water reducing agent composition of the present invention and a hydraulic material (cement), water, fine aggregate (sand) and coarse aggregate (gravel). Examples include concrete, medium-fluidity concrete, high-fluidity concrete, underwater non-separable concrete and sprayed concrete.

The hydraulic composition for mortar preferably contains the water reducing agent composition of the present invention and a hydraulic substance (cement), water and fine aggregate (sand), and its types include tiled mortar, repair mortar and Examples include self-leveling materials.

The hydraulic composition for cement paste preferably contains the water-reducing agent composition of the present invention, a hydraulic material (cement) and water, and fills the adhesives of tile-based inorganic building materials and members and empty walls of members. Examples include grout materials.

Examples of the hydraulic material include ordinary Portland cement, early strength Portland cement, moderate heat Portland cement, blast furnace cement, silica cement, fly ash cement, alumina cement, and super early strength Portland cement.
The hydraulic substances may be used alone or in combination of two or more. In addition, a commercially available thing can be used for a hydraulic substance.

From the viewpoint of ensuring strength, the content of the hydraulic substance (cement) is preferably 270 to 800 kg per 1 m ³ of concrete when the hydraulic composition is for concrete.
When the hydraulic composition is for mortar, it is preferably 300 to 1,000 kg per 1 m ³ of mortar.
When the hydraulic composition is for cement paste, it is preferably 500 to 1,600 kg per 1 m ^{3 of} cement paste.

The addition amount of the water reducing agent composition of the present invention is preferably 0.1 with respect to the unit cement amount (kg/m ³ ) from the viewpoints of fluidity, material separation resistance, setting delay, etc. in the hydraulic composition. -5 mass%, more preferably 0.3-3 mass%.

Examples of water include tap water and seawater, and from the viewpoint of preventing salt damage, tap water is preferable.

The water/cement ratio (W/C) in the hydraulic composition is preferably 30 to 75% by mass, more preferably 45 to 65% by mass, from the viewpoint of material separation in the hydraulic composition.

The hydraulic composition further comprises an aggregate, depending on its application. The aggregate includes fine aggregate and coarse aggregate.

As the fine aggregate, river sand, mountain sand, land sand, crushed sand and the like are preferable.

The sand cement ratio in the hydraulic composition is preferably 0.5 to 3.0 from the viewpoint of fluidity, cracking and cost of the hydraulic composition.

The particle diameter (maximum particle diameter) of the fine aggregate is preferably 5 mm or less.

The particle size distribution of the fine aggregate is preferably 0.075 to 5 mm, more preferably 0.075 to 2 mm, and further preferably 0.075 to 1 mm from the viewpoint of trowel coating workability of the mortar composition. The particle size distribution of the fine aggregate can be measured using a sieve having openings of 5 mm, 2.5 mm, 1.2 mm, 850 μm, 600 μm, 425 μm, 300 μm, 212 μm, 150 μm, 106 μm, 75 μm and 53 μm.

When the hydraulic composition is for concrete, the content of fine aggregate is preferably 400 to 1,100 kg, more preferably 500 to 1,000 kg per 1 m ^{3 of} concrete, and the hydraulic composition is for mortar. In the case of, it is preferably 500 to 2,000 kg, more preferably 600 to 1,600 kg per 1 m ^{3 of} mortar.

As the coarse aggregate, river gravel, mountain gravel, land gravel, crushed stone and the like are preferable.

The particle size (maximum particle size) of the coarse aggregate is larger than the particle size of the fine aggregate, preferably 40 mm or less, more preferably 25 mm or less.

When the hydraulic composition is for concrete, the content of coarse aggregate is preferably 600 to 1,200 kg, and more preferably 650 to 1,150 kg per 1 m ^{3 of} concrete.

When the hydraulic composition is for concrete, the fine aggregate ratio (volume percentage) in the aggregate is preferably 30 to 55% by volume, more preferably 35 to 55%, from the viewpoint of maintaining fluidity or sufficient strength. %, more preferably 35 to 50% by volume. The ratio of fine aggregate (volume %)=volume of fine aggregate/(volume of fine aggregate+volume of coarse aggregate)×100.

The aggregates may be used alone or in combination of two or more kinds. The aggregate may be a commercially available one.

If necessary, an admixture may be added to the hydraulic composition in order to suppress heat generation during curing and increase durability after curing. Examples of the admixture include blast furnace slag and fly ash.

From the viewpoint of developing the initial strength and durability of the hydraulic composition, the content of the admixture is preferably more than 0% by mass and 70% by mass or less when added. The admixture may be used alone or in combination of two or more kinds. As the admixture, a commercially available admixture can be used.

An AE agent (Air Entraining Agent) may be optionally used in the hydraulic composition in order to secure a predetermined amount of air and to obtain the durability of the hydraulic composition.

Examples of the AE agent include anionic surfactant-based, cationic surfactant-based, nonionic surfactant-based, amphoteric surfactant-based, rosin-based surfactant-based AE agents and the like.

Examples of the anionic surfactant system include carboxylic acid type, sulfuric acid ester type, sulfonic acid type and phosphoric acid ester type.
Examples of the cationic surfactant system include amine salt type, primary amine salt type, secondary amine salt type, tertiary amine salt type and quaternary amine salt type.
Examples of the nonionic surfactant system include ester type, ester/ether type, ether type and alkanolamide type.
Examples of the amphoteric surfactant system include amino acid type and sulfobetaine type.
Examples of the rosin-based surfactant system include abietic acid, neoabietic acid, parastoric acid, pimaric acid, isopimaric acid, dehydroabietic acid and the like.

From the viewpoint of the air content of the hydraulic composition, the amount of the AE agent added is preferably 0.0001 to 0.01 mass% with respect to the unit cement content (kg/m ³ ).

The AE agents may be used alone or in combination of two or more kinds. A commercially available AE agent can be used.

An antifoaming agent may be added to the hydraulic composition, if necessary, in order to obtain the strength of the hydraulic composition. Examples of the antifoaming agent include the same ones as those used in the water reducing agent composition.

From the viewpoint of dispersibility, the amount of the defoaming agent added is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the water-soluble cellulose ether.

In the hydraulic composition of the present invention, in order to control the physical properties of the hydraulic composition immediately after kneading (fresh concrete, fresh mortar or fresh cement paste), calcium chloride, lithium chloride, calcium formate, etc. are accelerated in setting. Agents and setting retarders such as sodium citrate and sodium gluconate can be used as necessary. Furthermore, in the hydraulic composition of the present invention, a shrinkage crack due to curing/drying, a crack shrinkage due to temperature stress due to heat of hydration reaction of cement, a drying shrinkage reducing agent, a hain-based or lime-based expansive material is added. It can be added if necessary.

The hydraulic composition described above can be manufactured by a conventional method. For example, first, a water reducing agent composition of the present invention, a hydraulic substance, and optionally an aggregate (fine aggregate and/or coarse aggregate) and an antifoaming agent are put in a mixer and kneading is performed. Then, water is added and kneaded to obtain a hydraulic composition.
Further, the water reducing agent composition and water may be mixed and added in advance.

As described above, according to the method for producing a hydraulic composition of the present invention, bleeding is suppressed and a fluid hydraulic composition is obtained.

Hereinafter, the present invention will be specifically described by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Examples 1 to 10 and Comparative Examples 1 and 2]
<Production of water reducing agent composition>
The water-reducing agent, water-soluble cellulose ether, gums, and defoaming agent shown below were weighed so as to have the addition amounts shown in Table 1, and these materials were stirred and mixed as follows using a stirrer to reduce water. An agent composition was produced.
(Examples 1 to 8 and Comparative Examples 1 and 2)
In all of Examples 1 to 8 and Comparative Examples 1 and 2, the stirring time is the addition of all the materials of the water reducing agent, the water-soluble cellulose ether, the gums, and the defoaming agent after the stirrer reaches the target peripheral speed. After that, it was set to 2 minutes.
As the water reducing agent, a polycarboxylic acid type water reducing agent and a naphthalene type water reducing agent were mixed in advance and added as a mixture of water reducing agents. The gums were added in powder form.
(Example 9)
In Example 9, after the stirrer reached the target peripheral speed, the mixture of water-soluble cellulose ether, gums, and defoaming agent was added to the polycarboxylic acid water reducing agent, the mixture was stirred for 1 minute, and then the naphthalene-based water reducing agent was used. Was added and stirred for another 1 minute.
The water-soluble cellulose ether, gums, and defoaming agent were added in powder form.
(Example 10)
In Example 10, after the stirrer reached the target peripheral speed, the mixture of the water-soluble cellulose ether, the gums and the defoaming agent was added to the naphthalene-based water reducing agent, the mixture was stirred for 1 minute, and then the polycarboxylic acid-based water reducing agent was used. The agent was added and the mixture was further stirred for 1 minute.
The water-soluble cellulose ether, gums, and defoaming agent were added in powder form.

<Materials used>
(A) Water-reducing agent (A-1) Carboxylic acid-based water-reducing agent, Chupol HP-11 (manufactured by Takemoto Yushi Co., Ltd.)
Solid content concentration: 24.3% by mass
Na ⁺ ion concentration; 16,000ppm
Water reduction rate: 19%
(A-2) Carboxylic acid-based water reducing agent, Chupol HP-11 (manufactured by Takemoto Yushi Co., Ltd.) diluted with water Solid content concentration: 15.0% by mass
Na ⁺ ion concentration: 9,880 ppm
Water reduction rate: 19%
(A-3) Naphthalene-based water reducing agent Mighty 150 (manufactured by Kao Corporation)
Solid content concentration: 39.7 mass%
Na ⁺ ion concentration: 35,000 ppm
Water reduction rate: 26%
(A-4) Naphthalene-based water reducing agent Mighty 150 (manufactured by Kao Corporation) diluted with water Solid content concentration: 15.0% by mass
Na ⁺ ion concentration: 13,200 ppm
Water reduction rate: 26%

(Method of measuring Na ⁺ ion concentration)
The Na ⁺ ion concentration of the water reducing agent (the above-mentioned carboxylic acid type water reducing agent, naphthalene type water reducing agent and a mixture thereof) was measured by the following method.
A sample of the water reducing agent used in the production of the water reducing agent composition is diluted with pure water to a concentration of 1/10000, and a 0.2 μm filter (trade name, liquid black disk (made by PTFE), made by Thermo Fisher Scientific Co., Ltd.) And was measured with an ion chromatograph DIONEX ICS-1600 (manufactured by Thermo Fisher Scientific) under the following measurement conditions.
(Measurement condition)
・Guard column: CG14 (made by Thermo Fisher Scientific Co.)
・Main column; CS14 (made by Thermo Fisher Scientific)
-Suppressor: CERS-500-4mm (made by Thermo Fisher Scientific)
・Column temperature: 30℃
・Liquid volume: 1 ml/min
・Injection amount: 25 μm
Eluent: 10 mM-MSA (metasulfonic acid)
The eluent was prepared by diluting 2 mol of metasulfonic acid with pure water to 10 mmol.

(B) Water-soluble cellulose ether/hydroxypropyl methylcellulose (HPMC)
(DS; 1.40, MS; 0.20, viscosity of 1 mass% aqueous solution at 20°C; 2,200 mPa·s)
・Hydroxyethyl methylcellulose (HEMC)
(DS; 1.50, MS; 0.20, viscosity of 1 mass% aqueous solution at 20° C.; 2,070 mPa·s)
・Hydroxyethyl cellulose (HEC)
(MS; 2.50, viscosity of 1% by mass aqueous solution at 20° C.; 2,070 mPa·s)
(C) Gums and xanthan gum (XG)
(KELTROL, manufactured by CP Kelco)
・Welan gum (WG)
(KELCO-CRETE WG, manufactured by CP Kelco)
・Daiyu Tangham (DG)
(KELCO-CRETE DG-F, manufactured by CP Kelco)
(D) Defoaming agent/oxyalkylene-based (OA-based) defoaming agent (SN Deformer 14HP, manufactured by San Nopco Ltd.)

<Stirring conditions>
-Agitator: Homo mixer (HM-310, manufactured by AS ONE)
Blade type: Turbine/stator blade Size (diameter): 29 mm
Rotation speed: 5,000 rpm
Peripheral speed: 7.6m/s

The sedimentation volume of the obtained water reducing agent composition was measured by the following method.
(Measurement of sedimentation volume)
Immediately after the above production, that is, immediately after being liquefied (uniformly dispersed), 100 ml of the water reducing agent composition was sampled in a graduated cylinder (32 mm in outer diameter, 100 ml in volume, manufactured by IWAKI) having a stopper and left at room temperature (20±3° C.) Immediately after collection (0 hour), after 24 hours, after 72 hours, and after every 168 hours, the boundary with the supernatant was visually observed. The volume ratio (suspension maintenance ratio) of the suspension layer (water reducing agent composition layer) to the entire liquid was determined as the sedimentation volume based on the scale corresponding to the boundary. For example, when the boundary with the supernatant is 0 mL, the sedimentation volume is 100% by volume, when the boundary with the supernatant is 90 mL, the sedimentation volume is 90% by volume, and the boundary with the supernatant is 50 mL. In the case of, the sedimentation volume is 50% by volume.

<Production of hydraulic composition (mortar)>
Next, using the water reducing agent composition produced as described above, a mortar was produced as a hydraulic composition as follows.
That is, dry mortar was prepared by putting a predetermined amount of cement and fine aggregate in a 5 liter mortar mixer (C138A-48, manufactured by Maruto Manufacturing Co., Ltd.) specified in JIS R 5201 and performing dry blending for 1 minute. .. Then, a mixture of the water reducing agent composition and a predetermined amount of water, which has been mixed in advance, is introduced, and the mixture is rotated at a low speed (rotation speed per minute: 140 revolutions, revolution speed: 62 revolutions per minute) for 3 minutes, as specified in JIS R5201. The mortar was produced by mixing. The conditions at this time are as follows.

<Materials used>
(1) Water-reducing agent composition: Water-reducing agent composition produced in each Example and Comparative Example (2) Cement: Ordinary Portland cement manufactured by Taiheiyo Cement Co., Ltd. (3) Fine aggregate: Mikawa silica sand No. 5 and 6, (Mikawa silica stone) (Made by the company, crushed sand, maximum particle size 2 mm, particle size distribution 0.075 to 0.425 mm)
(4) Water; tap water

<Mortar mix>
・Water cement ratio (W/C); 45% by mass
・Sand cement ratio: 1.0
・Amount of water reducing agent composition; C×0.50% by mass
In addition, W represents a unit water amount (kg/m ³ ), and C represents a unit cement amount (kg/m ³ ).

<Mortar temperature>
The material temperature was adjusted so that the kneading temperature of the mortar was 20±3°C.

The following table flow test was performed on the obtained hydraulic composition (mortar), and the table flow value was measured.
(Table flow test)
The test was performed according to JIS R5201. However, after the mortar was placed on the table, the operation of giving 15 shocks (falling motion) to the specified table was not performed, and the table flow value (0 hit flow) was measured without the shock. That is, the spread at the time when the flow was stopped after the mortar was placed on the table was taken as the table flow value (mortar flow value).
The above results are shown in Table 1.

As a result, regarding the storage stability of the water reducing agent composition, the water reducing agent compositions containing the polycarboxylic acid type water reducing agent and the naphthalene type water reducing agent of Examples 1 to 10 were the same as the polycarboxylic acid type water reducing agent of Comparative Example 1. As a result, the storage stability was improved up to 168 hours after the water reducing agent composition containing only the agent. Further, in all of Examples 1 to 10, the storage stability of the water reducing agent composition was improved while maintaining the Na ⁺ ion concentration of 10,000 ppm or more. Furthermore, in Examples 5 to 8, although one in which one of the combinations of the water-soluble cellulose ether and the gums is different from that in Example 4 is used, in any case, the composition of the water reducing agent composition is used. It has been found that storage stability is improved.
Next, regarding the fluidity of the hydraulic composition (mortar) using the water reducing agent composition, the water reducing agent compositions containing the polycarboxylic acid type water reducing agent and the naphthalene type water reducing agent of Examples 1 to 10 were used. All mortars showed good fluidity. On the other hand, in Comparative Example 2, since the mortar uses the water reducing agent composition containing only the naphthalene-based water reducing agent, the result is inferior in fluidity. Further, particularly in Examples 2 to 4, the result was excellent in fluidity, although the ratio of the naphthalene-based water reducing agent was large.
It is known that when a naphthalene-based water reducing agent and water-soluble cellulose are used in combination as in Comparative Example 2, both of them form a certain kind of complex, and as a result, the fluidity of the hydraulic composition is lowered. ing.
On the other hand, in the present invention, by using a polycarboxylic acid type water reducing agent and a naphthalene type water reducing agent in combination as the water reducing agent, the formation of this complex (complex) is avoided and the fluidity of the hydraulic composition is reduced. It is possible to achieve both high storage stability of the water reducing composition and fluidity of the hydraulic composition at a high level.

It should be noted that although the present invention has been described with reference to the above-described embodiment, the present invention is not limited to this embodiment, and a person skilled in the art can conceive of other embodiments, additions, changes, deletions, and the like. The present invention can be modified within the scope of the invention and is included in the scope of the invention as long as the effects of the invention are exhibited in any of the embodiments.

Claims (7)

A water reducing agent composition containing (A) a polycarboxylic acid water reducing agent and a naphthalene water reducing agent, (B) a water-soluble cellulose ether, (C) gums, and (D) a defoaming agent. The ratio SC _pc :SC _np of the solid content mass (SC _pc ) of the polycarboxylic acid water reducing agent and the solid content mass (SC _np ) of the naphthalene water reducing agent is 1:99 to 80:20. Water reducing agent composition. The water reducing agent composition according to claim 1 or 2, wherein the component (A) has a Na ⁺ ion concentration of 8,500 ppm or more. The water-reducing agent composition according to any one of claims 1 to 3, wherein the water-soluble cellulose ether is one kind or two or more kinds selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose and hydroxyalkyl alkyl cellulose. The water reducing agent composition according to any one of claims 1 to 4, wherein the gums are one kind or two or more kinds selected from the group consisting of diutan gum, welan gum, xanthan gum and gellan gum. A hydraulic composition comprising the water reducing agent composition according to claim 1, a hydraulic substance, and water. A method for producing a hydraulic composition, which comprises a step of mixing the water reducing agent composition according to any one of claims 1 to 5, a hydraulic substance, and water.