JP2021004146A - Water reducing agent composition, hydraulic composition and method of producing the same - Google Patents

Abstract

To provide a water reducing agent composition at least comprising a water reducing agent, a water soluble starch ether, and an antifoaming agent, exhibiting improved viscosity subsequent to being converted to one liquid (uniform dispersion), a hydraulic composition employing the same and a method of producing the same.SOLUTION: The water reducing agent composition comprises a water reducing agent, a water soluble starch ether, gum and an antifoaming agent. The water soluble starch ether is selected form the group consisting of alkyl starch, hydroxyalkyl starch, and hydroxyl alkyl starch.SELECTED DRAWING: None

Description

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

The hydraulic composition is a composition containing at least water, a hydraulic substance such as cement, an aggregate such as fine aggregate and / or coarse aggregate, and water, and is an aggregate of inorganic substances having different specific gravities, grain shapes, and particle sizes. Therefore, it is a composition in which material separation is likely to occur, and improvement thereof has been attempted by using a water-soluble polymer. For example, water-soluble cellulose ether and water-soluble starch ether are one of the few nonionic water-soluble polymers that can thicken even in a hydraulic composition having a pH of 12 or more and being strongly alkaline.

However, since water-soluble cellulose ethers and water-soluble starch ethers are generally used as powders, they are inferior in handling as compared with other liquid admixtures, and form mamaco at the time of addition or add a small amount. In some cases, it scatters and there is a problem that it is difficult to add a desired amount.

In order to solve these problems, for example, the viscosity of (A) a polycarboxylic acid-based copolymer and / or a salt thereof, and (B) a 2.0 wt% aqueous solution is 50 to 27,800 mPa · s at 20 ° C. An additive for a cement composition containing a water-soluble cellulose ether and (C) an antifoaming agent has been proposed (Japanese Patent Laid-Open No. 2008-137888 (Patent Document 1)).

Japanese Unexamined Patent Publication No. 2008-137889

However, even in Patent Document 1, the dispersed state of the water-soluble cellulose ether in the additive for cement composition may not be good, and when the hydraulic composition is produced by using it as it is, the hydraulic composition In some cases, it was not possible to provide the desired physical properties, and there was room for improvement. A similar problem also occurred when water-soluble starch ether was used.

The present invention has been made in view of the above circumstances, and is a water reducing agent composition containing at least a water reducing agent, a water-soluble starch ether, and a defoaming agent, and the viscosity after liquefaction (uniform dispersion) is improved. An object of the present invention is to provide a water-reducing agent composition, a water-hardening composition using the same, and a method for producing the same.

As a result of diligent research to solve the above problems, the present inventor has made a water reducing agent by using gums in a water reducing agent composition containing at least a water-soluble starch ether, a water reducing agent, and a defoaming agent. We have found that the storage stability of the composition after liquefaction (uniform dispersion) can be improved, and have made the present invention.

That is, the present invention provides the following water reducing agent composition, hydraulic composition, and a method for producing the same.
1. 1.
A water reducing agent composition containing a water reducing agent, a water-soluble starch ether, gums, and an antifoaming agent.
2. 2.
The water reducing agent composition according to 1, wherein the water-soluble starch ether is at least one selected from the group consisting of alkyl starch, hydroxyalkyl starch and hydroxyalkyl alkyl starch.
3. 3.
The water reducing agent composition according to 1 or 2, wherein the water reducing agent is at least one selected from the group consisting of a polycarboxylic acid-based water reducing agent, a naphthalene-based water reducing agent, a lignin-based water reducing agent, and a melamine-based water reducing agent.
4.
The water reducing agent composition according to any one of 1 to 3, wherein the gums are at least one selected from the group consisting of xanthan gum, welan gum and Daiyutan gum.
5.
The water reducing agent composition according to any one of 1 to 4, further comprising a water-soluble cellulose ether.
6.
The water reducing agent composition according to 5, wherein the water-soluble cellulose ether is at least one selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose and hydroxyalkyl alkyl cellulose.
7.
A hydraulic composition containing at least the water reducing agent composition according to any one of 1 to 6, a hydraulic substance, and water.
8.
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 6, a hydraulic substance, and water.

According to the present invention, by using gums in a water reducing agent composition containing at least a water-soluble starch ether, a water reducing agent and a defoaming agent, the water reducing agent composition is stored after liquefaction (uniform dispersion). Stability can be improved.

The present invention will be described below.
[Water reducing agent composition]
The water reducing agent composition according to the present invention is a composition for a hydraulic composition containing at least a water reducing agent, a water-soluble starch ether, gums, and an antifoaming agent (one-component water reducing agent). ..

(Water reducing agent)
Examples of the water reducing agent include polycarboxylic acid-based water reducing agents, naphthalene-based water reducing agents, lignin-based water reducing agents, melamine-based water reducing agents, and the like, and at least one selected from these is preferable.

Further, the water reducing agent referred to here is a chemical admixture that reduces the unit amount of water required to obtain a predetermined fluidity, and is a so-called high-performance water reducing agent, AE water reducing agent, high-performance AE water reducing agent, and AE water reducing agent. It contains all of what is called an agent (high-performance type), and any one of these is preferable.

Specific examples of the polycarboxylic acid-based water reducing agent include polycarboxylic acid ether-based compounds, polycarboxylic acid ether-based compounds and crosslinked polymers, polycarboxylic acid ether-based compounds and oriented polymers, and polycarboxylic acid ether-based compounds. Complex of compound and highly modified polymer, polyether carboxylic acid-based polymer compound, maleic acid copolymer, maleic acid ester copolymer, maleic acid derivative copolymer, carboxyl group-containing polyether compound, terminal sulfone group Examples thereof include a polycarboxylic acid group-containing multi-element polymer, a polycarboxylic acid-based graft copolymer, and a polycarboxylic acid ether-based polymer.
Its properties are preferably liquid.

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, still more preferably, from the viewpoint of economic efficiency or the amount added during the production of the water-hard composition. Is 13 to 20% by mass.

The solid content concentration can be measured as follows.
First, about 5 g of the water reducing agent is placed in a 16 ml weighing bottle, and the mass thereof, that is, the mass (g) of the water reducing agent before drying is measured. Then, it is dried in a dryer at 105 ° C. until it reaches a constant weight, and the mass (g) of the water reducing agent after drying is measured.
The solid content concentration can be calculated by the following formula using the measured masses of the water reducing agent before and after drying.
Solid content concentration (mass%) = {mass of water reducing agent after drying (g) / mass of water reducing agent before drying (g)} x 100

The Na ⁺ ion concentration of the polycarboxylic acid-based water reducing agent is preferably 1,000 ppm or more, more preferably 2,000 to 18, from the viewpoint of storage stability after liquefaction (uniform dispersion) of the water reducing agent composition. It is 000 ppm, more preferably 7,500 to 16,000 ppm, and particularly preferably 8,000 to 12,000 ppm.
The Na ⁺ ion concentration can be measured by an ion chromatograph method and will be described in detail in Examples.

Specific examples of the naphthalene-based water reducing agent include those containing naphthalene sulfonate or a derivative thereof as a main component.
Specific examples of the lignin-based water reducing agent include those containing lignin sulfonic acid or a salt thereof or a derivative thereof as a main component.
Specific examples of the melamine-based water reducing agent include a melamine sulfonic acid formarin condensate, a melamine sulfonate condensate, and a melamine sulfonate polyol condensate.
Two or more kinds of water reducing agents may be used in combination. Moreover, a commercially available water reducing agent can be used.

In the water-reducing agent composition, the water-reducing agent is a reference amount (for example, 100 parts by mass), and the components described below (water-soluble starch ether, gums and defoaming agent, if necessary) are used in a predetermined ratio with respect to the water-reducing agent. Water-soluble cellulose ether) is added.

(Water-soluble starch ether)
Examples of the water-soluble starch ether include alkyl starch, hydroxyalkyl starch, hydroxyalkyl alkyl starch and the like, and at least one selected from these is preferable.

Examples of alkyl starch include methyl starch, ethyl starch, propyl starch and the like.
Examples of hydroxyalkyl starch include hydroxymethyl starch, hydroxyethyl starch, hydroxypropyl starch and the like.
Examples of the hydroxyalkylalkyl starch include hydroxymethyl methyl starch, hydroxyethyl methyl starch, hydroxypropyl methyl starch and the like.

The origin of the water-soluble starch ether includes potato, tapioca, corn, etc., but the water-soluble starch ether used in the present invention has a viewpoint of storage stability after liquefaction (uniform dispersion) of the water reducing agent composition. Therefore, hydroxyalkyl starch derived from potato and hydroxyalkyl starch derived from tapioca are preferable.

The content (degree of substitution) of the hydroxyalkoxy group in the hydroxyalkyl starch derived from potato is preferably 5 to 30% by mass, more preferably 7 to 25% by mass, still more preferably 9 to 9 to 30% by mass from the viewpoint of solubility in water. It is 23% by mass.
The content of the hydroxyalkoxy group in the hydroxyalkyl starch derived from potato can be measured by the method of analyzing the degree of substitution of hydroxypropyl cellulose in the 17th revision of the Japanese Pharmacopoeia.

The viscosity of a 5% by mass aqueous solution of potato-derived hydroxyalkyl starch at 20 ° C. is preferably 10 to 1,000 mPa · s, more preferably 50 to 800 mPa · s, from the viewpoint of imparting a predetermined viscosity to the hydraulic composition. More preferably, it is 70 to 600 mPa · s.
The viscosity of a 5% by mass aqueous solution of potato-derived hydroxyalkyl starch at 20 ° C. can be measured using a B-type viscometer under measurement conditions of 30 rpm (hereinafter, the same applies to Examples).

The content (degree of substitution) of the hydroxyalkoxy group in the hydroxyalkyl starch derived from tapioca is preferably 0.5 to 20% by mass, more preferably 2 to 15% by mass, still more preferably from the viewpoint of solubility in water. It is 2.5 to 10% by mass.
The content of the hydroxyalkoxy group in the hydroxyalkyl starch derived from tapioca can be measured by the method of analyzing the degree of substitution of hydroxypropyl cellulose in the 17th revision of the Japanese Pharmacopoeia.

The viscosity of a 5% by mass aqueous solution of hydroxyalkyl starch derived from tapioca at 20 ° C. is preferably 2 to 1,000 mPa · s, more preferably 5 to 800 mPa · s, from the viewpoint of imparting a predetermined viscosity to the hydraulic composition. More preferably, it is 10 to 600 mPa · s.
The viscosity of a 5% by mass aqueous solution of hydroxyalkyl starch derived from tapioca at 20 ° C. can be measured using a B-type viscometer under measurement conditions of 30 rpm (hereinafter, the same applies to Examples).

The amount of the water-soluble starch ether added is preferably 0.1 to 20 parts by mass, more preferably 0.15 to 15 parts by mass with respect to 100 parts by mass of the water reducing agent from the viewpoint of imparting a predetermined viscosity to the water-hard composition. Parts, more preferably 0.15 to 10 parts by mass.
At this time, two or more types of water-soluble starch ether may be used in combination. Moreover, as the water-soluble starch ether, a commercially available one can be used.

(Gum)
Examples of gums include xanthan gum, welan gum, Daiyu tan gum and the like, and at least one selected from these is preferable. By using gums, it is possible to improve the apparent viscosity of the water reducing agent, improve the dispersion state of the water-soluble starch ether in the water reducing agent composition, and improve the storage stability after liquefaction (uniform dispersion). it can.

Like cellulose, xanthan gum has a main chain of β-1,4 bonds of D-glucose, and a side chain composed of two mannoses and one glucuronic acid.

The viscosity of a 1% by mass aqueous solution of xanthan gum at 20 ° C. is preferably 1,200 to 10,000 mPa · s, more preferably 1 from the viewpoint of storage stability after liquefaction (uniform dispersion) of the water reducing agent composition. , 500 to 7,000 mPa · s, more preferably 2,000 to 6,000 mPa · s.
The viscosity of a 1% by mass aqueous solution of xanthan gum at 20 ° C. can be measured using a B-type viscometer under measurement conditions of 12 rpm (hereinafter, the same applies to Examples).

The amount of xanthan gum added is preferable with respect to 100 parts by mass of the water reducing agent from the viewpoint of improving the dispersed state of the water-soluble starch ether in the water reducing agent composition and improving the storage stability after liquefaction (uniform dispersion). Is 0.005 to 2 parts by mass, more preferably 0.01 to 1 part by mass, and even more preferably 0.05 to 0.8 parts by mass.
At this time, two or more types of xanthan gum may be used in combination. In addition, commercially available xanthan gum can be used.

Welan gum has a structure in which an L-rhamnose or L-mannose side chain is bound to a main chain in which D-glucose, D-glucuronic acid, and L-rhamnose are bound at a ratio of 2: 2: 1.

The viscosity of a 1% by mass aqueous solution of welan gum at 20 ° C. is preferably 1,000 to 15,000 mPa · s, more preferably 2 from the viewpoint of storage stability after liquefaction (uniform dispersion) of the water reducing agent composition. It is 000 to 12,000 mPa · s, more preferably 2,500 to 7,500 mPa · s.
The viscosity of a 1% by mass aqueous solution of welan gum at 20 ° C. can be measured using a B-type viscometer under measurement conditions of 12 rpm.

The amount of welan gum added is preferable with respect to 100 parts by mass of the water reducing agent from the viewpoint of improving the dispersed state of the water-soluble starch ether in the water reducing agent composition and improving the storage stability after liquefaction (uniform dispersion). Is 0.01 to 20 parts by mass, more preferably 0.02 to 10 parts by mass, still more preferably 0.03 to 8 parts by mass.
At this time, two or more types of welan gum may be used in combination. In addition, a commercially available welan gum can be used.

Daiyutan gum is composed of D-glucose, D-glucuronic acid, D-glucose and L-rhamnose and two L-rhamnose.

The viscosity of a 1% by mass aqueous solution of Daiyutan gum at 20 ° C. is preferably 1,000 to 10,000 mPa · s, more preferably from the viewpoint of storage stability after liquefaction (uniform dispersion) of the water reducing agent composition. Is 2,000 to 7,000 mPa · s, more preferably 2,500 to 6,000 mPa · s.
The viscosity of a 1% by mass aqueous solution of Daiyutan gum at 20 ° C. can be measured using a B-type viscometer under measurement conditions of 12 rpm.

The amount of Daiyutan gum added is based on 100 parts by mass of the water reducing agent from the viewpoint of improving the dispersed state of the water-soluble starch ether in the water reducing agent composition and improving the storage stability after liquefaction (uniform dispersion). It is preferably 0.01 to 20 parts by mass, more preferably 0.02 to 10 parts by mass, and further preferably 0.03 to 8 parts by mass.
At this time, two or more types of Daiyu tan gum may be used in combination. In addition, commercially available Daiyu tan gum can be used.

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

Specific examples of the oxyalkylene-based defoaming agent include polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adduct; diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, and polyoxyethylene poly. (Poly) oxyalkylene alkyl ethers such as oxypropylene 2-ethylhexyl ether, higher alcohol having 8 or more carbon atoms and secondary alcohol having 12 to 14 carbon atoms with oxyethyleneoxypropylene adduct; polyoxypropylene phenyl ether, poly (Poly) oxyalkylene (alkyl) aryl ethers such as oxyethylene nonylphenyl ether; 2,4,7,9-tetramethyl-5-decine-4,7-diol, 2,5-dimethyl-3-hexin- Acetylene ethers obtained by addition-polymerizing alkylene oxide to acetylene alcohol such as 2,5-diol, 3-methyl-1-butin-3-ol; diethylene glycol oleic acid ester, diethylene glycol lauric acid ester, ethylene glycol distearate, poly (Poly) oxyalkylene fatty acid esters such as oxyalkylene oleic acid ester; (Poly) oxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolauric acid ester and polyoxyethylene sorbitan trioleic acid ester; Polyoxypropylene methyl ether sulfuric acid (Poly) oxyalkylene alkyl (aryl) ether sulfate esters such as sodium and polyoxyethylene dodecylphenol ether sulfate sodium; (poly) oxyalkylene alkyl phosphate esters such as (poly) oxyethylene stearyl phosphate; polyoxy (Poly) oxyalkylene alkyl amines such as ethylene lauryl amine; polyoxyalkylene amide and the like can be mentioned.

Specific examples of the silicone-based 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 antifoaming agent include octyl alcohol, 2-ethylhexyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like.

Specific examples of the mineral oil-based defoaming agent include kerosene and liquid paraffin.
Specific examples of the fatty acid-based antifoaming agent include oleic acid, stearic acid, and alkylene oxide adducts thereof.
Specific examples of the fatty acid ester antifoaming agent include glycerin monolithinolate, an alkenyl succinic acid derivative, sorbitol monolaurate, sorbitol trioleate, and natural wax.

Among these, an oxyalkylene defoaming agent is preferable from the viewpoint of efficiently defoaming the entrained air of the water-soluble starch ether and improving the storage stability after liquefaction (uniform dispersion).

The amount of the defoaming agent added is preferable with respect to 100 parts by mass of the water reducing agent from the viewpoint of efficiently defoaming the entrained air of the water-soluble starch ether and improving the storage stability after liquefaction (uniform dispersion). Is 0.001 to 16 parts by mass, more preferably 0.002 to 10 parts by mass, still more preferably 0.05 to 5 parts by mass.
At this time, two or more kinds of antifoaming agents may be used in combination. As the defoaming agent, a commercially available one can be used.

(Other ingredients)
The water reducing agent composition of the present invention may further contain a water-soluble cellulose ether.
The water-soluble cellulose ether is preferably nonionic, and is preferably an alkyl cellulose such as methyl cellulose; a hydroxyalkyl cellulose such as hydroxyethyl cellulose and hydroxypropyl cellulose; and a hydroxyalkyl alkyl such as hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose and hydroxyethyl ethyl cellulose. Cellulose is mentioned, and at least one selected from these is preferable.

Among the above alkyl celluloses, in methyl cellulose (MC), 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 alkyl cellulose can be obtained by converting a value that can be measured by the method of analyzing the degree of substitution of methyl cellulose in the 17th revised Japanese Pharmacopoeia.

Among the above hydroxyalkyl celluloses, in hydroxyethyl cellulose (HEC), the number of substituted molars (MS) of the hydroxyethoxy group is preferably 0.3 to 3.0, more preferably 0.5 to 2.8, and hydroxy. In propyl cellulose (HPC), the number of substituted molars (MS) of the hydroxypropoxy group is preferably 0.1 to 3.3, more preferably 0.3 to 3.0.
The number of substituted molars (MS) of hydroxyalkoxy groups in hydroxyalkyl cellulose can be obtained by converting a value that can be measured by the method for analyzing the degree of substitution of hydroxypropyl cellulose in the 17th revised Japanese Pharmacopoeia.

Among the above hydroxyalkylalkyl celluloses, in hydroxypropylmethyl cellulose (HPMC), the degree of substitution (DS) of the methoxy group is preferably 1.0 to 2.2, more preferably 1.3 to 1.9, and a hydroxypropoxy group. The substitution molar number (MS) of is preferably 0.1 to 0.6, more preferably 0.1 to 0.5. Further, in hydroxyethyl methyl cellulose (HEMC), 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 molar substitutions of the hydroxyethoxy group (MS). ) Is preferably 0.1 to 0.6, more preferably 0.15 to 0.4. Further, in hydroxyethyl ethyl cellulose (HEEC), 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 molar substitutions of the hydroxyethoxy group (MS). ) Is preferably 0.05 to 0.6, more preferably 0.1 to 0.5.
The degree of substitution of the alkoxy group and the number of moles of the hydroxyalkoxy group in the hydroxyalkylalkylcellulose can be converted into values that can be measured by the method for analyzing the degree of substitution of hypromellose (hydroxypropylmethylcellulose) described in the 17th revised Japanese Pharmacy. Can be sought.

The DS of the alkoxy group in alkyl cellulose or hydroxyalkyl alkyl cellulose represents the degree of substitution, and refers to the average number of methoxy groups per unit of anhydrous glucose.
Further, MS of a hydroxyalkoxy group in hydroxyalkyl cellulose and hydroxyalkyl alkyl cellulose represents the number of moles of substitution (molar suspension), and means the average number of moles of hydroxyalkoxy groups per mole of anhydrous glucose.

As the water-soluble cellulose ether, hydroxyalkylalkylcellulose such as hydroxypropylmethylcellulose and hydroxyethylmethylcellulose are preferable from the above-exemplified ones from the viewpoint of imparting material separation resistance in the water-hard composition.

The viscosity of a 1% by mass aqueous solution of water-soluble cellulose ether at 20 ° C. is preferably 130,000 mPa · s, more preferably 1.2 to 25,000 mPa · s, from the viewpoint of imparting a predetermined viscosity to the hydraulic composition. s, more preferably 1.5 to 20,000 mPa · s, and particularly preferably 1.5 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 measurement conditions of 12 rpm (hereinafter, the same applies to Examples).

The amount of the water-soluble cellulose ether added is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass, based on 100 parts by mass of the water reducing agent, from the viewpoint of imparting a predetermined viscosity to the hydraulic composition. It is a department.
At this time, two or more kinds of water-soluble cellulose ethers may be used in combination. Further, as the water-soluble cellulose ether, a commercially available one may be used, or one produced by a known method may be used.

According to the water reducing agent composition of the present invention, the storage stability is improved. For example, the sedimentation volume after standing at room temperature (20 ° C.) for 72 hours immediately after liquefaction (uniform dispersion) is preferably 70% by volume or more, more preferably 75% by volume or more. Further, according to the present invention, the sedimentation volume of the water reducing agent composition immediately after liquefaction (uniform dispersion) and after 168 hours at room temperature (20 ° C.) is preferably 50% by volume or more, more preferably 53% by volume or more. It is also possible.

Here, the sedimentation volume is defined as a predetermined amount (for example, 100 ml) of a water reducing agent composition immediately after one liquefaction (uniform dispersion) (immediately after mixing) is poured into a plugged graduated cylinder having a predetermined outer diameter (for example, 32 mm) and at room temperature (for example, 32 mm). It means the volume ratio (suspension retention rate) of the suspension layer (water reducing agent composition layer) to the entire liquid observed when the liquid 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 (uniform dispersion) (immediately after mixing) and the size (outer diameter and height) of the graduated cylinder used were determined by the suspension layer (water reduction) in the entire liquid at the time of the above observation. The height of the agent composition layer) (that is, the boundary position between the supernatant liquid and the suspension layer in the entire liquid) is not particularly limited as long as it can be clearly confirmed visually.

The water-reducing agent composition of the present invention is produced by a step of mixing a water-reducing agent, a water-soluble starch ether, gums, an antifoaming agent, and a water-soluble cellulose ether, if necessary, to obtain a water-reducing agent composition. can do.

At this time, the order of adding the water reducing agent, the water-soluble starch ether, the gums, and the defoaming agent (when the water-soluble cellulose ether is added, the order of addition including the water-soluble cellulose ether) is not particularly limited. ..

Further, the water-soluble starch ether, the gums, and the water-soluble cellulose ether added as needed may be added separately or may be added after being mixed in advance.
Further, the water-soluble starch ether, gums, and water-soluble cellulose ether 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 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 swivel mixer such as thin-film swirling type high-speed mixer (Filmix, manufactured by Primix), homogenizer (PH91, manufactured by SMT). ) Etc., or a high-speed stirrer to which those principles are applied. Of these, a rotor-stator type mixer or a cylindrical wall swivel mixer is preferable.

Examples of the type of stirrer (rotary blade) in the stirrer include a turbine / stator type, a thin film swirl type (PC wheel), a disper type and a perforated cage type, and the stirring efficiency and the water reducing agent composition are liquefied. From the viewpoint of storage stability after (uniform dispersion), turbine stator type and thin film swivel 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 portion (that is, the outermost circumference of the stirrer) of the stirrer (rotary blade) rotating in the stirrer.

The peripheral speed v (m / s) of the stirrer is calculated by the following equation from the diameter d (mm) of the stirrer and the rotation speed n (rpm (rotation speed per minute)) of the stirrer.
v = π × d × n / 60000

The mixing time (stirring time) is the water-soluble starch ether, the water reducing agent, the gums, and all the materials of the defoaming agent (when the water-soluble cellulose ether is added, all the materials including this water-soluble cellulose ether). The time after the material) is added and after reaching the target peripheral speed of the stirrer, or water-soluble starch ether, water reducing agent, gums, defoaming agent, and water-soluble added as necessary. The time after all the materials of the cellulose ether are added is not particularly limited, but is preferably 30 seconds or longer, more preferably 1 minute or longer, from the viewpoint of efficient productivity of the water reducing agent composition.
The upper limit of the mixing time is not particularly limited, but is preferably 60 minutes or less, more preferably 10 minutes or less, from the viewpoint of efficient productivity of the water reducing agent composition.

[Hydraulic composition and its production method]
The hydraulic composition according to the present invention is characterized by containing the above-mentioned water reducing agent composition of the present invention, a hydraulic substance, and water.

Further, the method for producing a hydraulic composition according to the present invention is characterized by including at least a step of mixing the above-mentioned water reducing agent composition of the present invention, a hydraulic substance, and water.

Specific uses of the hydraulic composition include concrete, mortar, cement paste and the like.

The water-hardening composition for concrete preferably contains the water-reducing agent composition of the present invention and a water-hardening substance (cement), water, fine aggregate (sand) and coarse aggregate (gravel), and is usually of the type. Examples thereof include concrete, medium-fluidity concrete, high-fluidity concrete, underwater inseparable concrete and shotcrete.

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

The hydraulic composition for cement paste preferably contains the hydraulic composition of the present invention, a hydraulic substance (cement) and water, and examples thereof include a member and a grout material for filling an empty wall of the member.

Examples of the water-hardening substance include water-hardening cements such as ordinary Portland cement, early-strength Portland cement, moderate heat Portland cement, blast furnace cement, silica cement, fly ash cement, alumina cement and ultra-fast-strength Portland cement.
The hydraulic substance may be used alone or in combination of two or more. As the hydraulic substance, a commercially available substance can be used.

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 amount of the water reducing agent composition added 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. It is ~ 5% by mass, more preferably 0.3 to 3% by mass.

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

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 use. Examples of the aggregate include 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 size (maximum particle size) 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, still more preferably 0.075 to 1 mm from the viewpoint of troweling workability of the mortar composition.
The particle size distribution of the fine aggregate can be measured using a sieve having a mesh size 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.

The content of the fine aggregate is preferably 400 to 1,100 kg, more preferably 500 to 1,000 kg per 1 m ^{3 of} concrete when the hydraulic composition is for concrete, and the hydraulic composition is for mortar. In the case of, the amount 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, and more preferably 25 mm or less.

When the hydraulic composition is for concrete, the content of the coarse aggregate is preferably 600 to 1,200 kg, 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. It is% by volume, more preferably 35 to 50% by volume.
The fine aggregate ratio (volume%) = the volume of the fine aggregate / (volume of the fine aggregate + volume of the coarse aggregate) × 100.

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

An admixture can be added to the hydraulic composition, if necessary, in order to suppress heat generation during curing and increase durability after curing.

Examples of the admixture include blast furnace slag and fly ash.

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

An AE agent (Air Entraining Agent) may be used in combination with the hydraulic composition, if necessary, in order to secure a predetermined amount of air and 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, and rosin-based surfactant-based AE agents.

Examples of the anionic surfactant system include a carboxylic acid type, a sulfate ester type, a sulfonic acid type, and a 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 an ester type, an ester ether type, an ether type, and an alkanolamide type.
Examples of amphoteric surfactant systems include amino acid type and sulfobetaine type.
Examples of the rosin-based surfactant system include abietic acid, neo-avietic acid, palastolic acid, pimalic acid, isopimalic acid, dehydroabietic acid and the like.

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

The AE agent may be used alone or in combination of two or more. As the AE agent, a commercially available one can be used.

An antifoaming agent may be added to the hydraulic composition of the present invention as necessary in order to obtain the strength of the hydraulic composition.
Examples of the defoaming agent include those similar to those used in the above-mentioned water reducing agent composition.

The amount of the defoaming agent added is preferably 0.1 to 50 parts by mass with respect to 100 parts by mass of the water-soluble starch ether from the viewpoint of suppressing foaming by the water-soluble starch ether.

In the hydraulic composition of the present invention, in order to control the physical properties of the hydraulic composition (fresh concrete, fresh mortar or fresh cement paste) immediately after kneading, the coagulation of calcium chloride, lithium chloride, calcium citrate and the like is promoted. Agents and coagulation retardants such as sodium citrate and sodium gluconate can be used as needed.

Further, in the hydraulic composition of the present invention, in order to prevent shrinkage cracks due to hardening and drying and cracks due to temperature stress due to the heat of hydration reaction of cement, a drying shrinkage reducing agent and an Auin-based or lime-based expanding material are used. It can be added as needed.

The hydraulic composition described above can be produced by a method for producing a hydraulic composition, which includes at least a step of mixing the hydraulic composition, the hydraulic substance, and water.

For example, first, the water-reducing agent composition of the present invention, a hydraulic substance, and if necessary, an aggregate (fine aggregate and / or coarse aggregate) and a defoaming agent are put into a mixer and kneaded in the air. 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 can be obtained.

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

[Examples 1 to 10, Comparative Example 1]
<Manufacturing of water reducing agent composition>
Weigh the water-soluble starch ethers, water-reducing agents, gums, defoamers, and water-soluble cellulose ethers shown below to the amounts shown in Table 1, and stirrers for these materials. A water reducing agent composition was produced by stirring and mixing using the above.
In all the examples and comparative examples, the stirring time was set after the stirrer reached the target peripheral speed, and then in Examples 1 to 4, all of the water-soluble starch ether, the water reducing agent, the gums, and the defoaming agent. In Examples 5 to 10, all the materials of water-soluble starch ether, water reducing agent, gums, defoamer, and water-soluble cellulose ether were used, and in Comparative Example 1, water-soluble starch ether and water reducing agent were used. After adding the defoamer and all the materials of the water-soluble cellulose ether, the time was 2 minutes.
The water-soluble starch ether, gums, and water-soluble cellulose ether were individually and simultaneously added to the water reducing agent in the form of powder, and a liquid defoaming agent was also added.

<Material used>
(1) Water reducing agent / polycarboxylic acid-based water reducing agent-A
Solid content concentration; 15.0% by mass
Na ⁺ ion concentration; 10,100 ppm
The polycarboxylic acid-based water reducing agent-A is a polycarboxylic acid-based water reducing agent (Chupol EX-60T, solid content concentration: 12.3% by mass, Na ⁺ ion concentration: 8,300 ppm, manufactured by Takemoto Oil & Fat Co., Ltd.). ) Weighed in a beaker and heated to 60 ° C. to concentrate and adjust the solid content concentration and Na ⁺ ion concentration.

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

(2) Hydroxypropyl starch (HPS-A) derived from water-soluble starch ether tapioca
(Excelcorn C250, Siam Modified Starch Co., manufactured by Ltd., Hydroxypropoxy group content 4.3% by mass, viscosity of 5% by mass aqueous solution at 20 ° C; 484.0 mPa · s)
-Hydroxypropyl starch derived from tapioca (HPS-B)
(Excelcorn 100, Siam Modified Starch Co., manufactured by Ltd., Hydroxypropoxy group content 3.9% by mass, viscosity of 5% by mass aqueous solution at 20 ° C.; 45.0 mPa · s)
-Hydroxypropyl starch derived from potato (HPS-C)
(EmsetKH6, manufactured by EMSLAND GROUP, hydroxypropoxy group content 17.1% by mass, viscosity of 5% by mass aqueous solution at 20 ° C; 313.0 mPa · s)

(3) Gum, xanthan gum (XG)
(KELTROL, CP Kelco, Viscosity of 1% by Mass Aqueous Solution at 20 ° C .; 3,110 mPa · s)

(4) Defoamer / oxyalkylene-based (OA-based) defoamer (SN Deformer 14HP, manufactured by San Nopco Co., Ltd.)

(5) Water-soluble cellulose ether hydroxypropylmethyl cellulose (HPMC-1)
(DS; 1.87, MS; 0.24, viscosity of 1% by mass aqueous solution at 20 ° C .; 2.0 mPa · s)
-Hydroxypropyl methylcellulose (HPMC-2)
(DS; 1.82, MS; 0.18, viscosity of 1% by mass aqueous solution at 20 ° C .; 2,090 mPa · s)
-Hydroxyethyl methyl cellulose (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)

<Stirring conditions>
・ Stirrer: Homo mixer (HM-310, manufactured by AS ONE)
Type of blade: Turbine / stator type Blade size (diameter): 29 mm
Rotation speed: 5,000 rpm
Peripheral speed: 7.6 m / 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 liquefaction (uniform dispersion), 100 mL of the water reducing agent composition was collected in a plugged graduated cylinder (outer diameter 32 mm, capacity 100 mL, manufactured by IWAKI) and left at room temperature (20 ± 3 ° C.). (Standing) was performed, and the boundary with the supernatant was visually observed immediately after collection (0 hours later), 24 hours later, 72 hours later, and 168 hours later. The volume ratio (suspension retention rate) 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, and 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.
The above results are shown in Table 1.

From the results of Example 1 and Comparative Example 1, by using gums, a water-reducing agent composition containing a water-soluble starch ether (hydroxyalkyl starch derived from tapioca), a water reducing agent, and a defoaming agent was precipitated at 20 ° C. The result was an improvement in volume.
Further, from Example 2, it was found that the same effect was exhibited even when hydroxyalkyl starch derived from tapioca having a different hydroxypropoxy group content and viscosity was used.
Furthermore, from Example 3, it was found that the same effect was exhibited even when hydroxyalkyl starch derived from potato was used. Comparing Examples 1 to 3, it was found that the hydroxyalkyl starch derived from tapioca was more effective.
Further, from Example 4, it was found that even when the addition amounts of the water-soluble starch ether, gums, and antifoaming agent were increased, the same effect as in Example 1 was exhibited.
Then, from Examples 5 to 7, it was found that even when the water-soluble cellulose ether was used in combination, the same effect as in Example 1 was exhibited.
In addition, from Examples 8 to 10, it was found that even when various water-soluble cellulose ethers were used in combination, the same effect as in Example 1 was exhibited.

Although the present invention has been described above with the embodiments shown above, the present invention is not limited to this embodiment, and other embodiments, additions, changes, deletions, etc. can be conceived by those skilled in the art. It can be changed within the range that can be changed, and is included in the scope of the present invention as long as the action and effect of the present invention are exhibited in any aspect.

Claims (8)

A water reducing agent composition containing a water reducing agent, a water-soluble starch ether, gums, and an antifoaming agent. The water reducing agent composition according to claim 1, wherein the water-soluble starch ether is at least one selected from the group consisting of alkyl starch, hydroxyalkyl starch and hydroxyalkyl alkyl starch. The water reducing agent composition according to claim 1 or 2, wherein the water reducing agent is at least one selected from the group consisting of a polycarboxylic acid-based water reducing agent, a naphthalene-based water reducing agent, a lignin-based water reducing agent, and a melamine-based water reducing agent. The water reducing agent composition according to any one of claims 1 to 3, wherein the gums are at least one selected from the group consisting of xanthan gum, welan gum and Daiyu tan gum. The water reducing agent composition according to any one of claims 1 to 4, further comprising a water-soluble cellulose ether. The water reducing agent composition according to claim 5, wherein the water-soluble cellulose ether is at least one selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose and hydroxyalkyl alkyl cellulose. A hydraulic composition containing at least the water reducing agent composition according to any one of claims 1 to 6, 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 6, a hydraulic substance, and water.