JP7230740B2 - Water-reducing agent composition and method for producing the same, and hydraulic composition and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a water reducing agent composition and its production method , and a hydraulic composition and its production method.

The hydraulic composition is a composition containing at least 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, particle shapes, and particle diameters. Therefore, it is a composition that is likely to cause material separation. Therefore, attempts have been made to improve the viscosity of the hydraulic composition by adding a water-soluble polymer as a thickening agent.

For example, water-soluble cellulose ether is under severe conditions for water-soluble polymers because the pH of cement is 12 or higher, which is a strong alkali, and there are many calcium ions originating from cement components. It is one of the few nonionic water-soluble polymers that can thicken hydraulic compositions.

However, since water-soluble cellulose ether is generally used in the form of powder, it is inferior to other liquid admixtures in terms of handling. Therefore, there is a problem that it is difficult to add the 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, an antifoaming agent, gums and a water-reducing agent are mixed in advance has been proposed (for example, JP-A-2016-056081). Publication (Patent Document 1)).

JP 2016-056081 A

However, in Patent Document 1, an attempt is made to improve the storage stability ^of the water reducing agent composition by using gums. In some cases, the performance was inferior, and there was room for improvement.

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

The inventors of the present invention have made intensive studies to solve the above problems, and found that a water reducing agent composition containing at least a polycarboxylic acid water reducing agent, a water-soluble cellulose ether, gums, and an antifoaming agent, Furthermore, by using a lignin-based water reducing agent together, the storage stability of the water reducing agent composition is improved even while maintaining a high Na ⁺ ion concentration, and in addition, the fluidity of the hydraulic composition is maintained at a high level. I found that it can be done, and came to make the present invention.

That is, the present invention provides the following water reducing agent composition and method for producing the same , and hydraulic composition and method for producing the same.
1.
(A) contains 10 to 50% by mass of a polycarboxylic acid-based water reducing agent and a lignin-based water reducing agent as a solid content in the entire water reducing agent , and the solid content mass (SC _pc ) of the polycarboxylic acid-based water reducing agent and the lignin-based water reducing agent 100 parts by mass of a water reducing agent having a solid content mass (SC _L ) ratio SC _pc : SC _L of 25:75 to 99:1 and a Na ⁺ ion concentration of 8,500 ppm or more ,
(B) water-soluble cellulose ether : 0.1 to 5 parts by mass ,
(C) one or more gums selected from the group consisting of diutan gum, welan gum, xanthan gum and gellan gum : in the case of diutan gum, 0.005 to 2 parts by mass, welan gum, xanthan gum or gellan gum 0.01 to 20 parts by mass , and
(D) Oxyalkylene antifoaming agent : 0.001 to 16 parts by mass
A one-liquid type water reducing agent composition obtained by mixing
2.
2. The water reducing agent according to 1, wherein the ratio of the solid content mass (SC _pc ) _of the polycarboxylic acid _- based water reducing agent to the solid content mass (SC _L ) of the lignin-based water reducing agent is 45:55 to 95:5. Composition.
3.
3. The water reducing agent composition according to 1 or 2, wherein the Na ⁺ ion concentration of component (A) is 9,500 to 50,000 ppm .
4.
4. The water reducing agent composition according to any one of 1 to 3, wherein the water-soluble cellulose ether is one or more selected from the group consisting of alkylcellulose, hydroxyalkylcellulose and hydroxyalkylalkylcellulose.
5 .
(C) The amount of gums added is 0.01 to 1 part by mass when diutan gum is added to 100 parts by mass of component (A), and when it is welan gum, xanthan gum or gellan gum, 0.05 5. The water reducing agent composition according to any one of 1 to 4, which is 10 parts by mass.
6 .
6. The water reducing agent composition according to any one of 1 to 5 , wherein (B) the water-soluble cellulose ether is added in an amount of 0.4 to 3 parts by mass per 100 parts by mass of component (A).
7 .
7. The water reducing agent composition according to any one of 1 to 6 , wherein (D) the antifoaming agent is added in an amount of 0.002 to 10 parts by mass per 100 parts by mass of component (A).
8 .
8. The water reducing agent composition according to any one of 1 to 7, which has a sedimentation volume of 40% by volume or more after standing still for 72 hours immediately after liquefaction.
9.
(A1) a liquid polycarboxylic acid-based water reducing agent,
(A2) a liquid lignin-based water reducing agent;
(B) a water-soluble cellulose ether;
(C) one or more gums selected from the group consisting of diutan gum, welan gum, xanthan gum and gellan gum, and
(D) Oxyalkylene antifoaming agent
having a step of mixing
The ratio of the solid content mass (SC _pc ) of the (A1) polycarboxylic acid-based water reducing agent to the solid content mass (SC _L ) of the (A2) lignin-based water reducing agent SC _pc : SCL _is 25:75 to 99:1. Yes, the total solid concentration of the components (A1) and (A2) is 10 to 50% by mass in the entire water reducing agent, and the total Na + ion concentration of the components (A1) and (A2) is 8,500 ppm or ^more . 9. The method for producing a one-component water reducing agent composition according to any one of 1 to 8, characterized in that:
10.
(A2) The Na ⁺ ion concentration of the lignin-based water reducing agent is greater than the Na ⁺ ion concentration of (A1) the polycarboxylic acid-based water reducing agent , and the absolute value of the difference between the two Na ⁺ ion concentrations is 1,500 to 50,000 ppm. 9. The method for producing a water reducing agent composition according to 9.
11.
9. A hydraulic composition comprising the water reducing agent composition according to any one of 1 to 8 , a hydraulic substance, and water.
12.
9. A method for producing a hydraulic composition, comprising the step of mixing the water reducing agent composition according to any one of 1 to 8 , a hydraulic substance and water.

According to the present invention, by using a polycarboxylic acid-based water reducing agent and a lignin-based water reducing agent in combination, the storage stability of the water reducing agent composition is improved, and an effect of suppressing bleeding when used in a hydraulic composition is expected. be. Furthermore, a fluid hydraulic composition can be produced.

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

((A) component)
Component (A) is a water reducing agent containing a polycarboxylic acid-based water reducing agent and a lignin-based water reducing agent, and preferably consists of a polycarboxylic acid-based water reducing agent and a lignin-based water reducing agent. The water reducing agent referred to here is a chemical admixture that reduces the unit amount of water required to obtain a predetermined slump flow, and is called a high performance water reducing agent, an AE water reducing agent, or a high performance AE water reducing agent. Any one of these is preferable.

Specific examples of polycarboxylic acid-based water reducing agents include polycarboxylic acid ether-based compounds, composites of polycarboxylic acid ether-based compounds and crosslinked polymers, composites of polycarboxylic acid ether-based compounds and oriented polymers, polycarboxylic acid ether-based compound and highly modified polymer complex, polyether carboxylic acid polymer compound, maleic acid copolymer, maleic acid ester copolymer, maleic acid derivative copolymer, carboxyl group-containing polyether compound, terminal sulfone group polycarboxylic acid group-containing multicomponent polymers, polycarboxylic acid-based graft copolymers, polycarboxylic acid ether-based polymers, and the like.

Moreover, a commercially available polycarboxylic acid-based water reducing agent can be used. Examples thereof include Tupole HP-11 (manufactured by Takemoto Yushi Co., Ltd.) and Master Glenium SP8SV X2 (manufactured by BASF Japan Ltd.). Its properties are preferably liquid. Moreover, if necessary, a commercially available polycarboxylic acid-based water reducing agent may be appropriately diluted with water.
Two or more kinds of polycarboxylic acid-based water reducing agents may be used in combination.

Specific examples of lignin-based water reducing agents include those containing ligninsulfonic acid, salts thereof, or derivatives thereof as a main component. Commercially available lignin-based water reducing agents can be used, for example, Darex WRDA (manufactured by GCP Chemicals Co., Ltd.), Master Pozzolith No. 70BASF Japan Co., Ltd.) and the like. Its properties are preferably liquid. Moreover, if necessary, a commercially available lignin-based water reducing agent may be appropriately diluted with water.
Two or more types of lignin-based water reducing agents may be used in combination.

The solid content concentration in the mixture of the polycarboxylic acid-based water-reducing agent and the lignin-based water-reducing agent (that is, (A) the water-reducing agent) is preferably 10% by mass or more from the viewpoint of storage stability after liquefaction (uniform dispersion). , more preferably 12.5 to 50% by mass, still more preferably 13 to 40% by mass, and particularly preferably 13 to 20% by mass. If the solid content concentration in component (A) is less than 10% by mass or more than 50% by mass, there is a risk that the storage stability after one-pack (uniform dispersion) will be reduced.

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

The ratio of the solid content mass (SC _pc ) of the polycarboxylic acid-based water reducing agent to the solid content mass (SC _L ) of the lignin-based water reducing agent in component (A) (mass ratio; SC _pc : _SCL ) From the viewpoint of storage stability after dispersion), the ratio is preferably 25:75 to 99:1, more preferably 45:55 to 95:5. If the content is out of the above range, the storage stability after one-pack (uniform dispersion) may be deteriorated.

The Na ⁺ ion concentration in the mixture of the polycarboxylic acid-based water reducing agent and the lignin-based water reducing agent (that is, (A) the water reducing agent) is preferably 8,500 ppm from the viewpoint of storage stability after liquefaction (uniform dispersion). Above, more preferably 9,000 to 50,000 ppm, still more preferably 9,500 to 20,000 ppm. If the Na ⁺ ion concentration in the component (A) is less than 8,500 ppm, the storage stability after one-liquidization (uniform dispersion) may deteriorate.
The Na ⁺ ion concentration of the water-reducing agent can be measured by ion chromatography (same below). Details will be described in Examples.

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

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

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

The water reducing rate of the polycarboxylic acid-based water reducing agent is preferably 18% or more, more preferably 19 to 30%, from the viewpoint of economy or the amount added during production of the hydraulic composition.
The water reduction rate of the water reducing agent can be obtained by calculation from the unit water content of the standard concrete and the test concrete specified in JIS A6204 (hereinafter the same).

The solid content concentration of the lignin-based water reducing agent is preferably 10 to 50% by mass, more preferably 10 to 48% by mass, and still more preferably 10 to 20%, from the viewpoint of economy or the amount added during production of the hydraulic composition. % by mass.

In addition, the Na ⁺ ion concentration of the lignin-based water reducing agent is preferably 8,500 ppm or more, more preferably 9,000 to 55,000 ppm, still more preferably from the viewpoint of storage stability after one-liquidization (uniform dispersion) 10,000 to 20,000 ppm.

The water reducing rate of the lignin-based water reducing agent is preferably 4% or more, more preferably 5 to 17%, from the viewpoint of fluidity of the hydraulic composition.

Furthermore, the absolute value of the difference between the Na ⁺ ion concentration of the polycarboxylic acid-based water reducing agent and the Na ⁺ ion concentration of the lignin-based water reducing agent is preferably 1, 1, 2 from the viewpoint of storage stability after liquefaction (uniform dispersion). 000 ppm or more, more preferably 1,500 to 50,000 ppm, still more preferably 1,750 to 40,000 ppm, and particularly preferably 2,000 to 10,000 ppm.
Also, from the viewpoint of storage stability after one-liquidization (uniform dispersion), the Na ⁺ ion concentration of the lignin-based water reducing agent is preferably higher than the Na ⁺ ion concentration of the polycarboxylic acid-based water reducing agent.

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

((B) component)
The water-soluble cellulose ethers are preferably nonionic and include alkylcelluloses such as methylcellulose; hydroxyalkylcelluloses such as hydroxyethylcellulose and hydroxypropylcellulose; and hydroxyalkylalkylcelluloses such as hydroxypropylmethylcellulose, hydroxyethylmethylcellulose and hydroxyethylethylcellulose. is mentioned.

Among the above alkylcelluloses, methylcellulose preferably has a methoxy group substitution degree (DS) of 1.0 to 2.2, more preferably 1.2 to 2.0. The degree of substitution (DS) of the alkoxy group in the alkyl cellulose can be obtained by converting a value that can be measured by the method of analyzing the degree of substitution of methyl cellulose according to the 17th revision of the Japanese Pharmacopoeia.

Among the above hydroxyalkyl celluloses, in hydroxyethyl cellulose, the molar number (MS) of hydroxyethoxy group substitution is preferably 0.3 to 3.0, more preferably 0.5 to 2.8, and in hydroxypropyl cellulose , the number of substituted moles (MS) of the hydroxypropoxy group is preferably 0.1 to 3.3, more preferably 0.3 to 3.0. The number of moles of substituted 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 Japanese Pharmacopoeia 17th Edition.

Among the above hydroxyalkylalkylcelluloses, in hydroxypropylmethylcellulose, the degree of substitution (DS) of methoxy groups is preferably 1.0 to 2.2, more preferably 1.3 to 1.9, and the substitution mole of hydroxypropoxy groups is The number (MS) is preferably between 0.1 and 0.6, more preferably between 0.1 and 0.5. In hydroxyethylmethylcellulose, the degree of substitution of methoxy groups (DS) is preferably 1.0 to 2.2, more preferably 1.3 to 1.9, and the number of moles of substitution of hydroxyethoxy groups (MS) is It is preferably 0.1 to 0.6, more preferably 0.15 to 0.4. In hydroxyethylethyl cellulose, the degree of substitution of ethoxy groups (DS) is preferably 1.0 to 2.2, more preferably 1.2 to 2.0, and the number of moles of substitution of hydroxyethoxy groups (MS) is It is preferably 0.05 to 0.6, more preferably 0.1 to 0.5. The degree of substitution of alkoxy groups and the number of moles of substituted hydroxyalkoxy groups in hydroxyalkylalkylcellulose are obtained by converting values that can be measured by the method of analyzing the degree of substitution of hypromellose (hydroxypropylmethylcellulose) described in the 17th revision of the Japanese Pharmacopoeia. can ask.

The DS of alkoxy groups in alkylcellulose, hydroxyalkylcellulose, and hydroxyalkylalkylcellulose represents the degree of substitution, and refers to the average number of methoxy groups per unit of anhydroglucose.
In addition, MS of hydroxyalkoxy groups in alkylcellulose, hydroxyalkylcellulose and hydroxyalkylalkylcellulose represents the number of moles of substitution (molar substitution), and means the average number of moles of hydroxyalkoxy groups per 1 mol of anhydroglucose.

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

The viscosity of a 1% by mass aqueous solution of the 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 giving a predetermined viscosity to the hydraulic composition. More preferably 500 to 20,000 mPa·s, 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 Brookfield viscometer under the measurement conditions of 12 rpm.

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

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

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

Diutan gum is composed of D-glucose, D-glucuronic acid, D-glucose and L-rhamnose and two L-rhamnoses.
Welan gum has a structure in which L-rhamnose or L-mannose side chains are bound to the main chain in which D-glucose, D-glucuronic acid, and L-rhamnose are bound in a ratio of 2:2:1.
Xanthan gum, like cellulose, has a main chain of β-1,4 bonds of D-glucose and side chains composed of two mannose and one glucuronic acid.
Gellan gum is a heteropolysaccharide composed of four repeating units of D-glucose, D-glucuronic acid and L-rhamnose linked in a ratio of 2:1:1.
By using gums, it is possible to improve the apparent viscosity of the water-reducing agent, improve the state of dispersion of the water-soluble cellulose ether in the water-reducing agent composition, and improve the storage stability after one-liquidization (uniform dispersion). can.

From the viewpoint of improving the dispersion state of the water-soluble cellulose ether in the water-reducing agent composition and improving the storage stability after one-pack (dispersion), the amount of gums added is, in the case of diutan gum, polycarboxylic acid-based water-reducing 0.005 to 2 parts by mass, more preferably 0.01 to 1 part by mass, still more preferably 0.01 to 1 part by mass per 100 parts by mass of the total mass of the agent and the lignin-based water reducing agent (that is, component (A)). It is 1 to 0.8 parts by mass. In the case of welan gum, xanthan gum, and gellan gum, the total weight of the polycarboxylic acid-based water reducing agent and the lignin-based water reducing agent (that is, component (A)) per 100 parts by weight, preferably 0.01 to 20 parts by weight, more It is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 8 parts by mass.

You may use gums individually or in combination of 2 or more types. In addition, commercially available gums can be used.

((D) component)
Examples of antifoaming agents include oxyalkylene antifoaming agents, silicone antifoaming agents, alcohol antifoaming agents, mineral oil antifoaming agents, fatty acid antifoaming agents, and fatty acid ester antifoaming agents.

Specific examples of oxyalkylene antifoaming agents include polyoxyalkylenes such as (poly)oxyethylene (poly)oxypropylene adducts; diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene poly Oxypropylene 2-ethylhexyl ether, (poly)oxyalkylene alkyl ethers such as oxyethyleneoxypropylene adducts to higher alcohols having 8 or more carbon atoms and secondary alcohols having 12 to 14 carbon atoms; polyoxypropylene phenyl ether, poly (Poly)oxyalkylene (alkyl)aryl ethers such as oxyethylene nonylphenyl ether; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne- Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohol such as 2,5-diol and 3-methyl-1-butyn-3-ol; diethylene glycol oleate, diethylene glycol laurate, ethylene glycol distearate, poly (Poly)oxyalkylene fatty acid esters such as oxyalkylene oleate; (poly)oxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan trioleate; polyoxypropylene methyl ether sulfate (Poly) oxyalkylene alkyl (aryl) ether sulfates such as sodium and sodium polyoxyethylene dodecylphenol ether sulfate; (poly) oxyalkylene alkyl phosphates such as (poly) oxyethylene stearyl phosphate; (poly)oxyalkylenealkylamines such as ethylene laurylamine; and polyoxyalkyleneamides.

Specific examples of silicone antifoaming agents include dimethylsilicone oil, silicone paste, silicone emulsion, organically modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), and fluorosilicone oil.

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

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

You may use an antifoamer individually or in combination of 2 or more types. In addition, a commercially available antifoaming agent can be used.

According to the water reducing agent composition of the present invention, storage stability is improved. For example, the sedimentation volume after standing for 72 hours immediately after liquefaction (uniform dispersion) is 40% by volume or more. Further, according to the present invention, the sedimentation volume after 168 hours from immediately after the one-liquidization (uniform dispersion) of the water-reducing agent composition can be made 30% by volume or more.

Here, the sedimentation volume is defined by pouring a predetermined amount (for example, 100 ml) of the water reducing agent composition immediately after liquefaction (uniform dispersion) (immediately after mixing) into a graduated cylinder with a predetermined outer diameter (for example, 32 mm), 20±3° C.) is the volume ratio (suspension retention rate) of the suspension layer (water-reducing agent composition layer) to the entire liquid observed when left standing 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 to be used were determined during the above observation. As long as the height of the agent composition layer) (that is, the boundary position between the supernatant liquid and the suspension layer in the entire liquid) can be clearly confirmed visually, there is no particular limitation.

The water-reducing agent composition of the present invention is produced by mixing a polycarboxylic acid-based water-reducing agent, a lignin-based water-reducing agent, a water-soluble cellulose ether, gums, and an antifoaming agent to obtain a water-reducing agent composition. can do.

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

Moreover, the polycarboxylic acid-based water reducing agent and the lignin-based water reducing agent may be added separately, or may be added after being mixed in advance. Moreover, the order of addition of the polycarboxylic acid-based water reducing agent and the lignin-based water reducing agent may be simultaneous, or one may be added first. For example, a polycarboxylic acid-based water reducing agent, a lignin-based water reducing agent, a water-soluble cellulose ether, gums, and an antifoaming agent are added in no particular order to a rotating stirrer of a stirrer, which will be described later, and mixed. Alternatively, a water-reducing agent mixture obtained by pre-mixing a polycarboxylic acid-based water-reducing agent and a lignin-based water-reducing agent, water-soluble cellulose ether, gums, and an antifoaming agent may be added in random order and mixed. Furthermore, either a polycarboxylic acid-based water-reducing agent or a lignin-based water-reducing agent is added, and then a pre-mixed mixture of water-soluble cellulose ether, gums, and an antifoaming agent is added for a certain period of time (1 minutes), and finally the remaining water reducing agent may be added and mixed.
Furthermore, gums may be added in either powder or aqueous solution form.

A mixing method is not particularly limited, and, for example, a stirrer can be used.
The stirrer is a device equipped with a stirrer (rotating blade) that rotates at high speed and a container in which the above materials can be mixed by the rotation of the stirrer. Rotor-stator mixers such as high-speed homomixer (LZB14-HM-1, manufactured by Chuo Rika Co., Ltd.), cylindrical wall swirl mixers such as thin-film swirl-type high-speed mixers (Filmics, manufactured by Primix), homogenizers (PH91, manufactured by SMT) ), etc., or a high-speed stirrer to which those principles are applied. Of these, rotor-stator mixers or cylindrical wall swirl mixers are preferred.

Types of stirrers (rotating blades) in stirrers include turbine stator type, thin film swirl type (PC wheel), disper type and perforated cage type. Turbine-stator type and thin-film spiral type (PC wheel) are preferred from the viewpoint of performance.

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

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

The mixing time (stirring time) is the time after all the materials including the water reducing agent, water-soluble cellulose ether, gums, and antifoaming agent are added and the target peripheral speed of the stirrer is reached, or the target speed of the stirrer. It is the time from when the water-reducing agent, water-soluble cellulose ether, gums, and antifoaming agent are all added, and is not particularly limited, but is effective productivity of the water-reducing agent composition. from the point of view, it is preferably 30 seconds or longer, more preferably 1 minute or longer. The upper limit of the mixing time is not particularly limited, but from the viewpoint of efficient productivity of the water reducing agent composition, it is preferably 60 minutes or less, more preferably 10 minutes or less.

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

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

The hydraulic composition for concrete preferably contains the water reducing agent composition of the present invention, a hydraulic substance (cement), water, fine aggregate (sand) and coarse aggregate (gravel). Concrete, medium-fluidity concrete, high-fluidity concrete, water-inseparable concrete, shotcrete and the like can be mentioned.

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

The hydraulic composition for cement paste preferably contains the water reducing agent composition of the present invention, a hydraulic substance (cement) and water, and is used as an adhesive for tile-based inorganic building materials or for filling empty walls between members. A grout material etc. are mentioned.

Examples of hydraulic substances include hydraulic cements such as ordinary Portland cement, high early strength Portland cement, moderate heat Portland cement, blast furnace cement, silica cement, fly ash cement, alumina cement and super high early strength Portland cement.
Hydraulic substances may be used alone or in combination of two or more. In addition, a commercial thing can be used for a hydraulic substance.

When the hydraulic composition is used for concrete, the content of the hydraulic substance (cement) is preferably 270 to 800 kg per 1 m ³ of concrete from the viewpoint of securing strength.
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 of the present invention to be added is preferably 0.1 per unit cement amount (kg/m ³ ) from the viewpoint of fluidity, material separation resistance, setting delay, etc. in the hydraulic composition. to 5% by mass, more preferably 0.3 to 3% by mass.

Examples of water include tap water and seawater, and 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 aggregate depending on its use. Aggregates include fine aggregates and coarse aggregates.

Preferred fine aggregates include river sand, mountain sand, land sand, and crushed sand.

The sand-cement ratio in the hydraulic composition is preferably 0.5 to 3.0 from the viewpoints 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 fine aggregate can be measured using sieves with openings of 5 mm, 2.5 mm, 1.2 mm, 850 μm, 600 μm, 425 μm, 300 μm, 212 μm, 150 μm, 106 μm, 75 μm, and 53 μm.

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

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

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

When the hydraulic composition is used for concrete, the content of coarse aggregate is preferably 600 to 1,200 kg, more preferably 650 to 1,150 kg per 1 m ³ of 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 when the hydraulic composition is for concrete. % by volume, more preferably 35 to 50% by volume. The ratio of fine aggregate (% by volume)=volume of fine aggregate/(volume of fine aggregate+volume of coarse aggregate)×100.

You may use an aggregate individually or in combination of 2 or more types. In addition, a commercially available aggregate can be used.

An admixture may be added to the hydraulic composition as needed in order to suppress heat generation during curing and increase durability after curing. Examples of admixtures include blast furnace slag and fly ash.

The content of the admixture, when added, is preferably more than 0% by mass and 70% by mass or less from the viewpoint of the development of initial strength and durability of the hydraulic composition. You may use an admixture individually or in combination of 2 or more types. In addition, a commercial thing can be used for an admixture.

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 durability of the hydraulic composition.

Examples of AE agents include AE agents such as anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, and rosin surfactants.

Examples of anionic surfactants include carboxylic acid type, sulfate type, sulfonic acid type, and phosphate type.
Examples of cationic surfactants include amine salt type, primary amine salt type, secondary amine salt type, tertiary amine salt type, and quaternary amine salt type.
Nonionic surfactants include ester-type, ester-ether-type, ether-type, and alkanolamide-type surfactants.
Amphoteric surfactants include amino acid type, sulfobetaine type and the like.
Rosin-based surfactants include abietic acid, neoabietic acid, parastric acid, pimaric acid, isopimaric acid, dehydroabietic acid, and the like.

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

The AE agents may be used alone or in combination of two or more. In addition, a commercially available AE agent can be used.

An antifoaming agent may be added to the hydraulic composition as needed in order to obtain the strength of the hydraulic composition. Examples of the antifoaming agent include those similar to those used in the water reducing agent composition.

The amount of the antifoaming agent to be added is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the water-soluble cellulose ether from the viewpoint of dispersibility.

In addition, in order to control the physical properties of the hydraulic composition (fresh concrete, fresh mortar or fresh cement paste) immediately after kneading, the hydraulic composition of the present invention contains a setting accelerator such as calcium chloride, lithium chloride, calcium formate, etc. A setting retardant such as sodium citrate and sodium gluconate can be used as necessary. Furthermore, the hydraulic composition of the present invention contains a drying shrinkage reducing agent and an auin-based or lime-based expansive agent in order to prevent shrinkage cracks due to curing and drying, and cracks due to temperature stress due to the heat of hydration reaction of cement. It can be added as needed.

The hydraulic composition described above can be produced by a conventional method. For example, first, the water reducing agent composition of the present invention, a hydraulic substance, and optionally aggregates (fine aggregates and/or coarse aggregates) and an antifoaming agent are put into a mixer, and dry kneaded. After that, water is added and kneaded to obtain a hydraulic composition.
Alternatively, the water reducing agent composition and water may be mixed in advance and added.

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

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[Examples 1 to 10, Comparative Examples 1 and 2]
<Production of water reducing agent composition>
The following water-reducing agents, water-soluble cellulose ethers, gums, and antifoaming agents were weighed so as to be added in the amounts shown in Table 1, and these materials were stirred and mixed using a stirrer as follows to reduce water. A composition was prepared.
(Examples 1 to 8, Comparative Examples 1 and 2)
For the stirring time in any of Examples 1 to 8 and Comparative Examples 1 and 2, after the stirrer reached the target peripheral speed, all materials including the water reducing agent, water-soluble cellulose ether, gums, and antifoaming agent were added. After that, it was set to 2 minutes.
The water reducing agent was added as a water reducing agent mixture obtained by previously mixing a polycarboxylic acid water reducing agent and a lignin water reducing agent. Moreover, gums were added in the form of powder.
(Example 9)
In Example 9, after the stirrer reaches the target peripheral speed, a mixture of water-soluble cellulose ether, gums, and antifoaming agent is added to the polycarboxylic acid water reducing agent, stirred for 1 minute, and then the lignin water reducing agent is added. was added and stirred for an additional minute.
The water-soluble cellulose ether, gums, and antifoaming agent were added in the form of powder.
(Example 10)
In Example 10, after the stirrer reached the target peripheral speed, a mixture of water-soluble cellulose ether, gums, and antifoaming agent was added to the lignin water reducing agent, stirred for 1 minute, and then polycarboxylic acid water reducing agent was added. agent was added and stirred for an additional minute.
The water-soluble cellulose ether, gums, and antifoaming agent were added in the form of powder.

<Materials used>
(A) Water-reducing agent (A-1) Carboxylic acid-based water-reducing agent Tupole HP-11 (manufactured by Takemoto Yushi Co., Ltd.)
Solid content concentration; 24.3% by mass
Na ⁺ ion concentration; 16,000 ppm
Water reduction rate: 19%
(A-2) Carboxylic acid-based water reducing agent Tupole HP-11 (manufactured by Takemoto Oil & Fat Co., Ltd.) diluted with water Solid content concentration; 15.0% by mass
Na ⁺ ion concentration; 9,880 ppm
Water reduction rate: 19%
(A-3) Lignin-based water reducing agent, Darex WRDA (manufactured by GCP Chemicals Co., Ltd.)
Solid content concentration; 14.2% by mass
Na ⁺ ion concentration; 12,000 ppm
Water reduction rate: 12%

(Method for measuring Na ⁺ ion concentration)
The Na ⁺ ion concentration of the water reducing agents (carboxylic acid water reducing agents, lignin water reducing agents and mixtures thereof) 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 Clodisc (manufactured by PTFE), manufactured by Thermo Fisher Scientific) and measured with an ion chromatograph DIONEX ICS-1600 (manufactured by Thermo Fisher Scientific) 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 volume: 25 μm
・ Eluent; 10 mM-MSA (methasulfonic acid)
The eluent was prepared by diluting 2 mol of methasulfonic acid to 10 mmol with pure water.

(B) Water-soluble cellulose ether hydroxypropyl methylcellulose (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% by mass aqueous solution at 20°C; 2,070 mPa s)
・Hydroxyethyl cellulose (HEC)
(MS; 2.50, viscosity at 20 ° C. of 1% by mass aqueous solution; 2,070 mPa s)
(C) gums xanthan gum (XG)
(KELTROL, manufactured by CP Kelco)
・Welan Gum (WG)
(KELCO-CRETE WG, manufactured by CP Kelco)
(D) Defoamer/Oxyalkylene-based (OA-based) defoamer (SN Deformer 14HP, manufactured by San Nopco Co., Ltd.)

<Stirring conditions>
・ Stirrer: Homomixer (HM-310, manufactured by AS ONE)
Blade type: turbine stator type Blade size (diameter): 29 mm
Rotation speed: 5,000 rpm
Peripheral speed: 7.6m/s

The sedimentation volume of the obtained water reducing agent composition was measured by the following method.
(Measurement of sedimentation volume)
100 ml of the water reducing agent composition immediately after the above production, that is, immediately after the one-component (uniform dispersion) is collected in a capped graduated cylinder (outer diameter 32 mm, capacity 100 ml, manufactured by IWAKI) and left at room temperature (20 ± 3 ° C.) ( The sample was allowed to stand still), and the boundary with the supernatant was visually observed immediately after collection (after 0 hour), after 24 hours, after 72 hours, and after every 168 hours. Based on the scale corresponding to the boundary, 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. For example, when the boundary with the supernatant liquid is 0 mL, the sedimentation volume is 100 vol%, and when the boundary with the supernatant liquid is 90 mL, the sedimentation volume is 90 vol%, and the boundary with the supernatant liquid is 50 mL. , the sedimentation volume is 50% by volume.

<Production of hydraulic composition (mortar)>
Next, using the water reducing agent composition produced as described above, a mortar was produced as a hydraulic composition as follows.
That is, a predetermined amount of cement and fine aggregate was placed in a 5-liter mortar mixer (C138A-48, manufactured by Maruto Seisakusho Co., Ltd.) according to JIS R 5201, and dry blended for 1 minute to prepare a dry mortar. . Next, a mixture of the above-mentioned water-reducing agent composition and a predetermined amount of water was added, and the mixture was stirred for 3 minutes at a low speed specified in JIS R 5201 (rotation speed: 140 rpm, revolution speed: 62 rpm). A mortar was produced by mixing. The conditions at this time are as follows.

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

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

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

The following table flow test was performed on the obtained hydraulic composition (mortar) to measure the table flow value.
(Table flow test)
A test was conducted according to JIS R 5201. However, after the mortar was placed on the table, the table flow value (zero stroke flow) was measured without performing the specified 15 impacts (drop motion) on the table. That is, the table flow value (mortar flow value) was defined as the spread at the time when the flow stopped after the mortar was placed on the table.
Table 1 shows the above results.

As a result of the above, when looking at the storage stability of the water reducing agent composition, the water reducing agent composition containing the polycarboxylic acid water reducing agent and the lignin water reducing agent of Examples 1 to 10 was superior to the polycarboxylic acid water reducing agent of Comparative Example 1. The storage stability up to 168 hours later was improved as compared with the water reducing agent composition containing only the agent. In addition, in Examples 2 to 5, 9, and 10, although the proportion of the polycarboxylic acid-based water reducing agent was increased, the storage stability was improved while maintaining the Na ⁺ ion concentration of 10,000 ppm or more. It had been. Furthermore, in Examples 6 to 8, one of the combinations of the water-soluble cellulose ether and gums was different from that in Example 5, but in any case, the water-reducing agent composition It has been found that storage stability is improved.
Next, regarding the fluidity of the hydraulic composition (mortar) using the water reducing agent composition, the water reducing agent composition containing the polycarboxylic acid water reducing agent and the lignin water reducing agent of Examples 1 to 10 was used. All mortars showed good fluidity. On the other hand, in Comparative Example 2, since the mortar used the water reducing agent composition containing only the lignin-based water reducing agent, the fluidity was poor.

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

Claims (12)

(A) contains 10 to 50% by mass of a polycarboxylic acid-based water reducing agent and a lignin-based water reducing agent as a solid content in the entire water reducing agent , and the solid content mass (SC _pc ) of the polycarboxylic acid-based water reducing agent and the lignin-based water reducing agent 100 parts by mass of a water reducing agent having a solid content mass (SC _L ) ratio SC _pc : SC _L of 25:75 to 99:1 and a Na ⁺ ion concentration of 8,500 ppm or more ,
(B) water-soluble cellulose ether : 0.1 to 5 parts by mass ,
(C) one or more gums selected from the group consisting of diutan gum, welan gum, xanthan gum and gellan gum : in the case of diutan gum, 0.005 to 2 parts by mass, welan gum, xanthan gum or gellan gum 0.01 to 20 parts by mass , and
(D) Oxyalkylene antifoaming agent : 0.001 to 16 parts by mass
A one-liquid type water reducing agent composition obtained by mixing 2. The method according to claim 1, wherein the ratio SC _pc : SCL of the solid content mass (SC _pc ) of _the polycarboxylic acid-based water reducing agent to the solid content mass (SC _L ) of the lignin-based water reducing agent is 45:55 to 95:5. A water reducing agent composition. 3. The water reducing agent composition according to claim 1, wherein the Na ⁺ ion concentration of component (A) is 9,500 to 50,000 ppm . The water reducing agent composition according to any one of claims 1 to 3, wherein the water-soluble cellulose ether is one or more selected from the group consisting of alkylcellulose, hydroxyalkylcellulose and hydroxyalkylalkylcellulose. (C) The amount of gums added is 0.01 to 1 part by mass when diutan gum is added to 100 parts by mass of component (A), and when it is welan gum, xanthan gum or gellan gum, 0.05 5. The water reducing agent composition according to any one of claims 1 to 4, wherein the amount is from 1 to 10 parts by mass. The water reducing agent composition according to any one of claims 1 to 5 , wherein the amount of water-soluble cellulose ether (B) added is 0.4 to 3 parts by mass per 100 parts by mass of component (A). 7. The water reducing agent composition according to any one of claims 1 to 6 , wherein (D) the antifoaming agent is added in an amount of 0.002 to 10 parts by mass per 100 parts by mass of component (A). 8. The water reducing agent composition according to any one of claims 1 to 7, which has a sedimentation volume of 40% by volume or more after standing still for 72 hours immediately after liquefaction. (A1) a liquid polycarboxylic acid-based water reducing agent,
(A2) a liquid lignin-based water reducing agent;
(B) a water-soluble cellulose ether;
(C) one or more gums selected from the group consisting of diutan gum, welan gum, xanthan gum and gellan gum, and
(D) Oxyalkylene antifoaming agent
having a step of mixing
Solid content mass (SC _pc ) and (A2) the solid content mass of the lignin-based water reducing agent (SC _L. ) ratio SC _pc : SC _L. is 25:75 to 99:1, the total solid content concentration of the components (A1) and (A2) in the entire water reducing agent is 10 to 50% by mass, and the total concentration of the components (A1) and (A2) is Na ⁺ The method for producing a one-component water reducing agent composition according to any one of claims 1 to 8, characterized in that the ion concentration is 8,500 ppm or more. (A2) Na of lignin-based water reducing agent ⁺ The ion concentration is (A1) Na of the polycarboxylic acid-based water reducing agent ⁺ greater than the ion concentration, both Na ⁺ 10. The method for producing a water reducing agent composition according to claim 9, wherein the absolute value of the ion concentration difference is 1,500 to 50,000 ppm. A hydraulic composition comprising the water reducing agent composition according to any one of claims 1 to 8 , a hydraulic substance, and water. A method for producing a hydraulic composition, comprising the step of mixing the water reducing agent composition according to any one of claims 1 to 8 , a hydraulic substance, and water.