JP2020196637A - Water-reducing agent composition and hydraulic composition and method for producing the same - Google Patents

Abstract

To provide a water-reducing agent composition at least containing a water-reducing agent, a gum, and an antifoaming agent, wherein the composition shows improvement in the storage stability after turned into a single liquid (uniform dispersion).SOLUTION: A water-reducing agent composition contains a water-reducing agent, a gum containing xanthan gum and diutan gum, and an antifoaming agent.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 a fine aggregate and / or a 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, the water-soluble cellulose ether is one of the few nonionic water-soluble polymers capable of thickening even in a hydraulic composition having a pH of 12 or more and being strongly alkaline.

However, since the water-soluble cellulose ether is generally used as a powder, it is inferior in handling as compared with other liquid admixtures, and forms mamaco at the time of addition or scatters when a small amount is added. Therefore, there is a problem that it is difficult to add a desired amount.

In order to solve these problems, a water reducing agent composition (one-component water reducing agent) in which a water-soluble cellulose ether, a defoaming agent, gums and a water reducing agent are mixed has been proposed in advance (Japanese Patent Laid-Open No. 2016-056081). Gazette (Patent Document 1)).

Japanese Unexamined Patent Publication No. 2016-056081

However, in Patent Document 1, an attempt is made to improve the storage stability of the water reducing agent composition after liquefaction (uniform dispersion) by using gums, but depending on the type of gum, liquefaction (uniformity) is attempted. Storage stability after (dispersion) may be inferior, and there was room for improvement.

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, gums, and an antifoaming agent, and the storage stability after liquefaction (uniform dispersion) thereof. It is an object of the present invention to provide an improved water reducing agent composition, a hydraulic composition using the same, and a method for producing the same.

As a result of diligent research to solve the above problems, the present inventors have added xanthan gum to a water reducing agent composition containing at least Daiyutan gum, a water reducing agent, and a defoaming agent. Storage stability after liquefaction (uniform dispersion) of the water-reducing agent composition (particularly, storage stability at room temperature (20 ° C.)) is improved, and in addition, the material of the water-hard composition containing the water-reducing agent composition It has been found that the separation resistance is also improved, and the present invention has been made.

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, gums containing xanthan gum and Daiyutan gum, and an antifoaming agent.
2. 2.
The water reducing agent composition according to 1, wherein the water reducing agent is one or more 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 sulfonic acid-based water reducing agent. ..
3. 3.
The water reducing agent composition according to 1 or 2, further comprising a water-soluble cellulose ether.
4.
3. The water reducing agent composition according to 3, wherein the water-soluble cellulose ether is one or more selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose and hydroxyalkyl alkyl cellulose.
5.
The water reducing agent composition according to any one of 1 to 4, wherein the mass ratio of the xanthan gum to the dieu tan gum is 95: 5 to 5:95.
6.
A hydraulic composition containing at least the water reducing agent composition according to any one of 1 to 5, a hydraulic substance, 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 substance, and water.

According to the present invention, by using xanthan gum and Daiyutan gum in combination, the storage stability of the water reducing agent composition after liquefaction (uniform dispersion) is improved, and the bleeding suppressing effect when used in a hydraulic composition is improved. There is expected.

The present invention will be described below.
[Water reducing agent composition]
The water reducing agent composition according to the present invention is a composition (one-component water reducing agent) for a hydraulic composition containing at least a water reducing agent, gums containing xanthan gum and Daiyutan gum, and a defoaming agent. is there.

(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, and melamine-based water reducing agents.

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 hydraulic 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 8,500 to 16,000 ppm, and particularly preferably 9,000 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 of the present invention, the water reducing agent is a reference amount (for example, 100 parts by mass), and the components described below (xanthan gum and Daiyutan gum gums and defoaming agent) are added in a predetermined ratio to the water reducing agent. To do.

(Gum)
The gums include xanthan gum and daiyutan gum, preferably composed of xanthan gum and daiyutan gum.

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.

Two or more types of xanthan gum may be used in combination. In addition, commercially available xanthan gum can be used.

By using xanthan gum, the apparent viscosity of the water reducing agent is increased, the dispersed state of Daiyutan gum in the water reducing agent composition is improved, and the storage stability after liquefaction (uniform dispersion) (particularly at room temperature (20 ° C.)). Storage stability in) can be improved.

The amount of xanthan gum added is preferably relative to 100 parts by mass of the water reducing agent from the viewpoint of improving the dispersed state of the water reducing agent composition of Daiyutan gum and improving the storage stability after liquefaction (uniform dispersion). It is 0.005 to 2 parts by mass, more preferably 0.01 to 1 part by mass, and further preferably 0.05 to 0.8 parts by mass.

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, from the viewpoint of imparting a predetermined viscosity to the hydraulic composition and imparting material separation resistance. It is preferably 2,000 to 7,000 mPa · s, and 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.

Two or more types of Daiyu tan gum may be used in combination. In addition, commercially available chewing gum can be used.

The amount of Daiyutan gum added is preferably 0.01 to 20 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 hydraulic composition and imparting material separation resistance. It is preferably 0.02 to 10 parts by mass, and more preferably 0.03 to 8 parts by mass.

The ratio ( _MXG : M _DG ) of the mass of xanthan gum ( _MXG ) to the mass of Daiyutan gum (M _DG ) in the water reducing agent composition of the present invention is one liquefaction (uniform dispersion) of the water reducing agent composition. From the viewpoint of storage stability later, it is preferably 95: 5 to 5:95, more preferably 85:15 to 10:90, still more preferably 75:25 to 25:75, and particularly preferably 75:25 to 40: It is 60.

The absolute value of the difference in viscosity of each 1% by mass aqueous solution (20 ° C.) of xanthan gum and Daiyutan gum is preferably 100 mPa. From the viewpoint of storage stability after liquefaction (uniform dispersion) of the water reducing agent composition. It is s or more, more preferably 200 to 1,000 mPa · s.

Further, from the viewpoint of storage stability after liquefaction (uniform dispersion) of the water reducing agent composition, the viscosity of the 1% by mass aqueous solution of dayutan gum at 20 ° C. is higher than the viscosity of the 1% by mass aqueous solution of xanthan gum at 20 ° C. Is also preferable.

(Defoamer)
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-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 and oxyethylene oxypropylene 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 sulfate (Poly) oxyalkylene alkyl (aryl) ether sulfate esters such as sodium and polyoxyethylene dodecylphenol ether sodium sulfate; (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, alkenyl succinic acid derivative, sorbitol monolaurate, sorbitol trioleate, and natural wax.

Among these, an oxyalkylene-based defoaming agent is preferable from the viewpoint of efficiently defoaming the entrained air of xanthan gum and Daiyu tan gum and improving the storage stability after liquefaction (uniform dispersion).

The amount of the defoaming agent added is based on 100 parts by mass of the water reducing agent from the viewpoint of efficiently defoaming the entrained air of xanthan gum and Daiyutan gum 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.

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 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. It is preferably one or more selected from the group consisting of.

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 moles substituted (MS) of the hydroxyethoxy group is preferably 0.30 to 3.00, more preferably 0.50 to 2.80, and hydroxy. In propyl cellulose (HPC), the number of moles substituted (MS) of the hydroxypropoxy group is preferably 0.30 to 3.30, more preferably 0.10 to 3.00.
The number of moles of hydroxyalkoxy group substitution (MS) 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 hydroxypropylmethylcellulose (HPMC), the degree of substitution (DS) of the methoxy group is preferably 1.00 to 2.20, more preferably 1.30 to 1.90, and a hydroxypropoxy group. The number of substitution moles (MS) of the above is preferably 0.10 to 0.60, more preferably 0.10 to 0.50. Further, in hydroxyethyl methyl cellulose (HEMC), the degree of substitution (DS) of the methoxy group is preferably 1.00 to 2.20, more preferably 1.30 to 1.90, and the number of moles of substitution of the hydroxyethoxy group (MS). ) Is preferably 0.10 to 0.60, more preferably 0.15 to 0.40. Further, in hydroxyethyl ethyl cellulose (HEEC), the degree of substitution (DS) of the ethoxy group is preferably 1.00 to 2.20, more preferably 1.20 to 2.00, and the number of moles of substitution of the hydroxyethoxy group (MS). ) Is preferably 0.05 to 0.60, more preferably 0.10 to 0.50.
The degree of substitution (DS) of the alkoxy group and the number of moles of substitution (MS) of the hydroxyalkoxy group in hydroxyalkylalkylcellulose can be measured by the method for analyzing the degree of substitution of hypromellose (hydroxypropylmethylcellulose) described in the 17th revised Japanese Pharmacopoeia. It can be obtained by converting the value.

The DS of the alkoxy group in alkyl cellulose and hydroxyalkyl alkyl cellulose represents the degree of substitution, and refers to the average number of methoxy groups per unit of anhydrous glucose.
The MS of the hydroxyalkoxy group in hydroxyalkyl cellulose and hydroxyalkyl alkyl cellulose represents the number of moles of substitution (molar substation), and refers to 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 hydroxyethyl methyl cellulose are preferable from the above-exemplified ones from the viewpoint of imparting material separation resistance in 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. More preferably, it is 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 measurement conditions of 12 rpm.

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.

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 settling volume after standing at room temperature (20 ° C.) for 72 hours immediately after liquefaction is preferably 50% by volume or more, more preferably 70% by volume or more, and settling after standing at high temperature (40 ° C.) for 72 hours. The volume is preferably 45% by volume or more, more preferably 90% by volume or more. Further, according to the present invention, the sedimentation volume of the water reducing agent composition immediately after liquefaction and after 168 hours at room temperature (20 ° C.) can be preferably 45% by volume or more, more preferably 65% by volume or more. ..

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.) and high temperature (40 ± 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 shall be produced by a step of mixing gums containing xanthan gum and Daiyutan gum, a water reducing agent, a defoaming agent, and if necessary, a water-soluble cellulose ether to obtain a water reducing agent composition. Can be done.

At this time, the order of adding xanthan gum, Daiyu tan gum, a water reducing agent, and an antifoaming agent (when adding the water-soluble cellulose ether, the order of adding the water-soluble cellulose ether) is not particularly limited.

Further, xanthan gum and Daiyutan gum may be added separately or may be added after being mixed in advance. Further, xanthan gum and dieutan gum may be added in either powder or aqueous solution form.

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 swirl 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 after all the materials including xanthan gum and chewing gum including xanthan gum, a water reducing agent, a defoaming agent, and if necessary, a water-soluble cellulose ether are added. Time after reaching the target peripheral speed of the child, or after reaching the target peripheral speed of the stirrer, gums containing xanthan gum and Daiyutan gum, a water reducing agent, an antifoaming agent, and if necessary. This is the time after all the materials including the water-soluble cellulose ether are added, and is not particularly limited, but from the viewpoint of efficient productivity of the water reducing agent composition, it is preferably 30 seconds or more, more preferably 1 minute. That is all. 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.

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, if 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 defoam gum from the viewpoint of suppressing foaming by the defoam gum.

In addition, 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 condensation of calcium chloride, lithium chloride, calcium citrate and the like is promoted. Agents and setting retarders 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 agent 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, a hydraulic composition in which material separation resistance is improved and bleeding is suppressed 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 7, Comparative Examples 1 to 4]
<Manufacturing of water reducing agent composition>
Weigh xanthan gum, Daiyu tan gum, water reducing agent, defoaming agent, and water-soluble cellulose ether as shown below to the amounts shown in Table 1, and use a stirrer for these materials. Stir and mix to produce a water reducing agent composition. In all of the examples and comparative examples, the stirring time was set to xanthan gum, dieutan gum, a water reducing agent, a defoaming agent, and if necessary, a water-soluble cellulose ether after the stirrer reached the target peripheral speed. After adding all the ingredients, the time was 2 minutes.
Xanthan gum and Daiyu tan gum were added individually and simultaneously in the form of powder.
In Examples 1 to 3 and Comparative Examples 1 and 2, no water-soluble cellulose ether was used.

<Material used>
(1) Water reducing agent / polycarboxylic acid-based water reducing agent-A
Solid content concentration; 15.5% by mass
Na ⁺ ion concentration; 10,500 ppm
-Polycarboxylic acid-based water reducing agent-B
Solid content concentration; 14.0% by mass
Na ⁺ ion concentration; 9,400 ppm
The polycarboxylic acid-based water reducing agents-A and B are polycarboxylic acid-based water reducing agents (Chupol EX-60T, solid content concentration; 12.3% by mass, Na ⁺ ion concentration; 8,300 ppm, Takemoto Oil & Fat Co., Ltd. ) Is weighed in a beaker and concentrated by heating to 60 ° C. to adjust the solid content concentration and Na ⁺ ion concentration.

(Measurement method of Na ⁺ ion concentration)
The Na ⁺ ion concentrations of the polycarboxylic acid-based water reducing agents -A and B were measured by the following methods.
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 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 metasulfonic acid with pure water to 10 mmol.

(2) Gum, xanthan gum (XG)
(KELTROL, CP Kelco, Viscosity of 1% by Mass Aqueous Solution at 20 ° C .; 3,110 mPa · s)
・ Daiyu Tangham (DG)
(KELCO-CRETE DG-F, CP Kelco, Viscosity of 1% by Mass Aqueous Solution at 20 ° C .; 4,000 mPa · s)

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

(4) Water-soluble cellulose ether hydroxypropylmethyl cellulose (HPMC)
(DS; 1.40, MS; 0.20, viscosity of 1% by mass aqueous solution at 20 ° C .; 2,200 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
Number of root turns: 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) at room temperature (20 ± 3 ° C) and high temperature (20 ± 3 ° C.) It was left to stand (standing) at 40 ± 3 ° C.), and the boundary with the supernatant was visually observed immediately after collection (0 hours), 24 hours, 72 hours, and 168 hours. 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 air was left at a high temperature (40 ± 3 ° C.) (standing) using a blower dryer.

<Manufacturing 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, a dry mortar was prepared by putting a predetermined amount of cement and fine aggregate in a JIS R 5201 default 5 liter mortar mixer (C138A-48, manufactured by Maruto Seisakusho Co., Ltd.) and performing a dry blend for 1 minute. .. Next, a mixture of the above water reducing agent composition and a predetermined amount of water in advance is added, and the speed is defined in JIS R5201 at a low speed (rotation speed: 140 rotations per minute, revolution speed: 62 rotations per minute) for 3 minutes. A mortar was produced by mixing. The conditions at this time are as follows.

<Material used>
(1) Water reducing agent composition: Water reducing agent composition produced in each example and comparative example (2) Cement: Ordinary Portland cement 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 formulation>
-Water-cement ratio (W / C); 45% by mass
・ Sand cement ratio; 1.0
-Amount of water reducing agent composition added; C x 0.50% by mass
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 viscosity measurement test was carried out on the obtained hydraulic composition (mortar) to measure the apparent viscosity.
Using a T-bar stage TS-20 (Toki Sangyo Co., Ltd., model: TV-10R) as a viscometer, 400 g of mortar to be measured was collected in a beaker with a capacity of 500 ml and rotated at a rotation speed of 5 rpm for 2 minutes. , The viscosity was read. As the rotor, a T-type spindle set having a T-bar portion having a length of 20.4 mm (“TD”) was used.
The above results are shown in Table 1.

As a result, from Examples 1 to 3 and Comparative Examples 1 and 2, the combined use of xanthan gum and Daiyutan gum improved the sedimentation volume of the water reducing agent composition at 20 ° C. and 40 ° C. In addition, since good results were obtained with respect to the apparent viscosity of the hydraulic composition, improvement in material separation resistance was also observed.
Specifically, Examples 1 to 3 have an improved 20 ° C. sedimentation volume and a reduced apparent viscosity of the hydraulic composition as compared with Comparative Example 1 of Xanthan gum alone, and are more than Comparative Example 2 of xanthan gum alone. The 40 ° C. sedimentation volume was improved. Further, in Examples 1 to 3, there was a tendency that the sedimentation volume at 20 ° C. was improved as the mass ratio (XG: DG) of xanthan gum and Daiyutan gum increased.
Further, from Examples 4 and 5 and Comparative Examples 3 and 4, the same improvement effect was confirmed even when the water-soluble cellulose ether was used.
In addition, from Examples 6 and 7, the same improvement effect was confirmed even when various cellulose ethers were used.

Although the present invention has been described above with the above-described embodiment, the present invention is not limited to this embodiment, and those skilled in the art may think of other embodiments, additions, changes, deletions, and the like. It can be changed within the range possible, 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 (7)

A water reducing agent composition containing a water reducing agent, gums containing xanthan gum and Daiyutan gum, and an antifoaming agent. The water reducing agent according to claim 1, wherein the water reducing agent is one or more 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 sulfonic acid-based water reducing agent. Composition. The water reducing agent composition according to claim 1 or 2, further comprising a water-soluble cellulose ether. The water reducing agent composition according to claim 3, wherein the water-soluble cellulose ether is one or more 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 mass ratio of the xanthan gum to the die utan gum is 95: 5 to 5:95. A hydraulic composition containing at least the water reducing agent composition according to any one of claims 1 to 5, 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.