WO2020085192A1 - Dispersant composition for hydraulic compositions for centrifugal molding or vibration molding - Google Patents

Abstract

The present invention is a dispersant composition for hydraulic compositions for centrifugal molding or vibration molding, which contains a copolymer that has a weight average molecular weight of from 30,000 to 100,000 (inclusive) and contains, as constituent monomers, an acrylic acid or a salt thereof, a methacrylic acid or a salt thereof, and a compound represented by general formula (1), with the ratio of the acrylic acid or a salt thereof in the total of the acrylic acid or a salt thereof and the methacrylic acid or a salt thereof being from 20 mol% to 70 mol% (inclusive). (In the formula, R¹ and R³ may be the same or different and each represents a hydrogen atom or an alkyl group having from 1 to 3 (inclusive) carbon atoms; R² represents a hydrogen atom or a methyl group; and n represents the average number of added moles, which is a number of from 5 to 150 (inclusive).)

Description

Dispersant composition for hydraulic composition for centrifugal molding or vibration molding

The present invention relates to a dispersant composition for a hydraulic composition for centrifugal molding or vibration molding and a method for producing the same, a hydraulic composition for centrifugal molding or vibration molding and a method for producing the same, and a method for producing a cured product of the hydraulic composition.

BACKGROUND ART Centrifugal molding is known as a method for producing hollow cylindrical concrete molded products such as pipes, piles and poles. This centrifugal molding method is a method in which a kneaded concrete material is put into a mold and the concrete is pressed against the inner surface of the mold by centrifugal force generated by rotating the mold at a high speed. The formwork has joints parallel to the rotation axis, and during the centrifugal compaction process of concrete, large vibrations are applied to the concrete due to the joints of the formframes splashing the formwork during centrifugal molding. It is one of the factors that contribute to firmness.

In hydraulic compositions for centrifugal molding, naphthalene-based dispersants are often used as the dispersant from the viewpoint of moldability of centrifugally molded products, but there is a growing need for higher strength and earthquake resistance both in Japan and overseas. However, in a region where a high-strength hardened body is required, in a region where the unit water amount of concrete is small, a region where it is difficult to knead with a naphthalene-based dispersant appears, which makes practical use difficult. For this reason, the use of polycarboxylic acid-based dispersants having high water-reducing properties has been promoted, but a problem when using the polycarboxylic acid-based dispersants is the centrifugal (vibration) compaction property of the centrifugally molded product. In the Architectural Institute of Japan Structural Papers, No. 606, pages 29-34 (General Incorporated Foundation, Architectural Institute of Japan, published in August 2006), a naphthalene-based dispersant is used in a region where the water binder ratio is 20% or more. There is.

Centrifugal compaction is a property that indicates the degree of compaction of concrete during centrifugal molding. It depends on the filling property of mortar in the aggregate gap during centrifugal molding and the shape retention (property to maintain the shape) after molding. It is considered to be dominated. Therefore, it is considered that the centrifugal compaction property of the concrete during centrifugal molding reflects the thixotropic property of the concrete as a fluid.

If the centrifugal compaction property of the centrifugally molded product is not good, the strength development of the cured product after centrifugal molding will be reduced, the centrifugal compaction process will take time, and the productivity will be impaired. Defects such as exfoliation of hardened concrete (shelf drop) will occur. Therefore, a hydraulic composition for centrifugal molding is desired to exhibit more excellent centrifugal compaction property.

Japanese Patent Application Laid-Open No. 61-122147 discloses a concrete containing amorphous ultrafine silica, a high-performance raw water additive and a centrifugal molding aid, and having a water cement ratio of 35% or less, and a centrifugal force of 35 G or less at a medium speed. There is disclosed a method for producing concrete, which is characterized by compacting with.

In JP-A-2017-122027, (A) a reaction step of polymerizing a monomer in a solution to obtain a dispersant for a hydraulic composition, and (B) after the reaction step, further heating is performed and unreacted. The aging step of advancing the polymerization reaction of the monomer, (C) the cooling step of adjusting the temperature of the solution containing the dispersant for the hydraulic composition obtained in the aging step, and the (D) obtained in the cooling step. And a neutralization step of neutralizing and adjusting the pH of the solution containing the dispersant for hydraulic composition, and (E) adjusting the concentration of the solution containing the dispersant for hydraulic composition obtained in the neutralization step. The method for producing a dispersant for a hydraulic composition is described in which the diluting steps are performed in this order.

In Japanese Patent Laid-Open No. 2003-221266, a structural unit (I) derived from a specific unsaturated (poly) alkylene glycol ether-based monomer (a), another specific unsaturated polyalkylene glycol ether-based monomer ( The structural unit (II) derived from (b) and the structural unit (III) derived from the unsaturated monocarboxylic acid-based monomer (c) are included as essential structural units, and the structural unit (I) and the structural unit ( II) and the structural unit (III) each account for 1% by weight or more of all the structural units, and the total ratio of the structural unit (I) and the structural unit (II) is 50 mol% or less in the total structural unit. The cement admixture containing the copolymer (A) as an essential component is described.

Japanese Unexamined Patent Publication No. 2002-348161 discloses a constitutional unit (I) derived from a specific unsaturated polyalkylene glycol ether monomer (a1) and a specific unsaturated monocarboxylic acid type monomer (b) derived from the structural unit (I). A cement dispersant containing a copolymer containing a structural unit (II) as an essential component, wherein the structural unit (II) includes at least a structure derived from methacrylic acid (salt). Has been done.

JP-A-58-74552 discloses a specific polyalkylene glycol mono (meth) acrylic acid ester-based monomer, a specific (meth) acrylic acid-based monomer, and any monomer polymerizable with these. A cement dispersant containing, as a main component, a copolymer or a neutralized product thereof derived from the above is described.

SUMMARY OF THE INVENTION The present invention provides a dispersant composition for a hydraulic composition capable of imparting excellent vibration moldability to a hydraulic composition that is molded using an external force such as centrifugal molding or vibration molding.

The present invention includes, as constituent monomers, acrylic acid or a salt thereof, methacrylic acid or a salt thereof, and a compound represented by the following general formula (1), and a total of acrylic acid or a salt thereof and methacrylic acid or a salt thereof. Among them, for a hydraulic composition for centrifugal molding or vibration molding, which contains a copolymer having a proportion of acrylic acid or a salt thereof of 20 mol% or more and 70 mol% or less and a weight average molecular weight of 30,000 or more and 100,000 or less. Dispersant composition.

(In the formula, R ¹ and R ³ are the same or different and each represents an alkyl group having 1 to 3 carbon atoms, R ² represents a hydrogen atom or a methyl group, and n is an average number of moles added and is 5 to 150. Indicates the number.)

The present invention also contains the dispersant composition for a hydraulic composition for centrifugal molding or vibration molding of the present invention, water, and a hydraulic powder, and the water / hydraulic powder ratio is 10% by mass or more. 25% by mass or less of the hydraulic composition for centrifugal molding or vibration molding.

The present invention also relates to a method for improving the compaction property of a hydraulic composition by centrifugal force, using the dispersant composition for a hydraulic composition for centrifugal molding or vibration molding of the present invention.

The present invention also relates to a method for producing a hydraulic composition, which comprises mixing the dispersant composition for a hydraulic composition for centrifugal molding or vibration molding of the present invention, water, and a hydraulic powder.

Further, the present invention is to produce a hydraulic composition by mixing the dispersant composition for a hydraulic composition for centrifugal molding or vibration molding of the present invention, water, and a hydraulic powder, and the hydraulic composition The present invention relates to a method for producing a cured product of a hydraulic composition, in which a mold is filled with an object and then the mold is clamped by applying a centrifugal force.

Further, the present invention is to produce a hydraulic composition by mixing the dispersant composition for a hydraulic composition for centrifugal molding or vibration molding of the present invention, water, and a hydraulic powder, and the hydraulic composition The present invention relates to a method for producing a cured product of a hydraulic composition, in which a mold is filled with a product and then the mold is clamped with vibration.

Hereinafter, the copolymer will be referred to as component (A).
The dispersant composition for hydraulic composition for centrifugal molding or vibration molding of the present invention may be referred to as the dispersant composition for hydraulic composition of the present invention or the dispersant composition of the present invention.
Further, the hydraulic composition for centrifugal molding or vibration molding of the present invention may be referred to as the hydraulic composition of the present invention.

According to the present invention, there is provided a dispersant composition for a hydraulic composition, which can impart excellent vibration moldability to a hydraulic composition used for molding using vibration such as centrifugal molding and vibration molding.

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have found that concrete using a dispersant composition containing the component (A) has improved vibration moldability such as centrifugal compaction property by centrifugal molding. It was The reason why such an effect is exhibited is not always clear, but it is presumed as follows. The structural unit of acrylic acid or a salt thereof imparts flexibility to the copolymer of the component (A) due to its high molecular mobility, and the excluded volume of the polycarboxylic acid-based dispersant containing the structural unit contains the structure. It will be bigger than the one without. As a result, the absolute coating area of the surface of the hydraulic particles is reduced, the hydration reaction is promoted (a delay in setting is avoided), and a dense structure is formed by the hydration product, which results in a hydraulic composition. It is considered that the thixotropy of the product is improved and the excellent vibration response is brought about. In addition, since the vibration is generated by the rotation of the metallic mold during centrifugal molding, it is considered that during centrifugal molding, when fluidized, it fluidizes and the filling of the aggregate progresses, resulting in excellent centrifugal compaction.

<Dispersant composition for hydraulic composition>
The component (A) is a copolymer having a predetermined weight average molecular weight containing acrylic acid or a salt thereof, methacrylic acid or a salt thereof, and a compound represented by the following general formula (1) as constituent monomers. The component (A) has a proportion of acrylic acid or a salt thereof of 20 mol% or more and 70 mol% or less in the total of acrylic acid or a salt thereof and methacrylic acid or a salt thereof.

The component (A) has a proportion of acrylic acid or a salt thereof of 20 mol% or more, preferably 30 mol% or more in the total of acrylic acid or a salt thereof and methacrylic acid or a salt thereof, from the viewpoint of vibration response and centrifugal compaction property. , More preferably 40 mol% or more, and 70 mol% or less, preferably 65 mol% or less, more preferably 60 mol% or less.

From the viewpoint of vibration responsiveness and centrifugal compaction property, the component (A) is acrylic acid or its salt in the total of acrylic acid or its salt, methacrylic acid or its salt, and the compound represented by the above general formula (1). The total proportion of the salt and methacrylic acid or its salt is preferably 50 mol% or more, more preferably 60 mol% or more, further preferably 65 mol% or more, and preferably 95 mol% or less, more preferably 85 mol% or less, further preferably Is 77 mol% or less.

In the component (A), the total proportion of acrylic acid or a salt thereof, methacrylic acid or a salt thereof, and the compound represented by the general formula (1) in the total amount of the constituent monomers is preferably 50 mol% or more, It is more preferably 70 mol% or more, and preferably 100 mol% or less, and may be 100 mol%.

Examples of the salt of acrylic acid and the salt of methacrylic acid include an alkali metal salt, an alkaline earth metal salt (1/2 atom), an ammonium salt, an alkylammonium salt, or an alkenylammonium salt, and preferably an alkali metal salt. , An alkaline earth metal salt (1/2 atom), an alkyl ammonium salt, or an alkenyl ammonium salt, and more preferably an alkali metal salt, an alkaline earth metal salt (1/2 atom), or an alkyl ammonium salt.

In general formula (1), R ¹ is preferably a methyl group.
In general formula (1), R ² is preferably a hydrogen atom.
In general formula (1), R ³ is preferably a methyl group or a hydrogen atom.
In the general formula (1), n is the average number of moles added, preferably 10 or more, more preferably 20 or more, further preferably 30 or more, still more preferably 40 or more, and preferably 90 or less, more preferably Is 80 or less, more preferably 70 or less, even more preferably 60 or less, still more preferably 55 or less.

The component (A) has a weight average molecular weight of 30,000 or more, preferably 32,000 or more, more preferably 35,000 or more, from the viewpoint of imparting excellent vibration moldability to the hydraulic composition. It is 100,000 or less, preferably 60,000 or less, more preferably 50,000 or less, still more preferably 45,000 or less, still more preferably 40,000 or less. This weight average molecular weight is measured by gel permeation chromatography (GPC) under the following conditions.
* GPC condition device: GPC (HLC-8320GPC) Tosoh Corporation column: G4000PWXL + G2500PWXL (Tosoh Corporation)
Eluent: 0.2 M phosphoric acid buffer _/ CH 3 CN = _9/1
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detection: RI
Sample size: 0.2mg / mL
Standard substance: Polyethylene glycol equivalent (monodisperse polyethylene glycol: molecular weight 87,500, 250,000, 145,000, 46,000, 24,000)

The dispersant composition for hydraulic composition of the present invention may further contain a strength improver and / or a retarder.

Examples of the strength improver include a polyol compound, an alkali metal thiosulfate, an alkaline earth metal thiosulfate, an alkaline metal thiocyanate, an alkaline earth metal thiocyanate, an alkaline metal sulfate and an alkaline earth metal sulfate. To be The strength improver is preferably one or more selected from polyol compounds. Examples of the polyol compound include glycerin, glycerin ester derivatives, glycol compounds, and sugar alcohols. The polyol compound is preferably glycerin.

Examples of the retarder include oxycarboxylic acid, polyvalent carboxylic acid, reducing polysaccharide and sugar alcohol. The retarder is preferably one or more selected from oxycarboxylic acids. The oxycarboxylic acid is gluconic acid and / or its salt, glycolic acid and / or its salt, tartronic acid and / or its salt, glyceric acid and / or its salt, tartaric acid and / or its salt, citric acid and / or its Salt, salicylic acid and / or its salt, gallic acid and / or its salt are mentioned. The oxycarboxylic acid is preferably gluconic acid and / or a salt thereof.

The dispersant composition for hydraulic compositions of the present invention preferably contains component (A) in an amount of 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and preferably 90% by mass. The following content is more preferably 70% by mass or less, further preferably 50% by mass or less. The dispersant composition for hydraulic compositions of the present invention may have a content of the component (A) of 100% by mass, that is, a component (A).

When the dispersant composition for a hydraulic composition of the present invention contains a strength improver, its content is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and , Preferably 10% by mass or less, more preferably 5% by mass or less.

When the dispersant composition for hydraulic composition of the present invention contains a strength improver, the mass ratio of the content of the component (A) to the content of the strength improver is the content of the strength improver / ( The content of component A) is preferably 0.01 or more, more preferably 0.03 or more, still more preferably 0.045 or more, and preferably 1 or less, more preferably 0.5 or less, still more preferably 0. 0.2 or less, more preferably 0.1 or less, still more preferably 0.07 or less.

When the hydraulic composition dispersant composition of the present invention contains a retarder, the content thereof is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and It is preferably 10% by mass or less, more preferably 5% by mass or less.

When the dispersant composition for a hydraulic composition of the present invention contains a retarder, the mass ratio of the content of the component (A) and the content of the retarder is the content of the retarder / the component of (A). Content is preferably 0.01 or more, more preferably 0.02 or more, and preferably 1 or less, more preferably 0.5 or less, still more preferably 0.2 or less, still more preferably 0.1 or less. Or less, more preferably 0.07 or less, still more preferably 0.05 or less.

The dispersant composition for hydraulic compositions of the present invention may further contain a polycarboxylic acid dispersant (hereinafter referred to as other polycarboxylic acid dispersant) composed of a copolymer other than the component (A). it can. Other polycarboxylic acid-based dispersants include copolymers of methacrylic acid or a salt thereof and a compound represented by the general formula (1), which have a known structure and composition as a dispersant. Can be mentioned.
When the dispersant composition for hydraulic composition of the present invention contains other polycarboxylic acid type dispersant, the mass ratio of other polycarboxylic acid type dispersant / (A) component is preferably 0.01. Or more, more preferably 0.1 or more, and preferably 10 or less, more preferably 1 or less, still more preferably 0.5 or less, even more preferably 0.3 or less, still more preferably 0.2 or less. .
In the dispersant composition for hydraulic composition of the present invention, the mass ratio of the total content of the strength improver and the retarder and the total content of the component (A) and the other polycarboxylic acid-based dispersant is ( (Total content of strength improver and retarder) / (total content of (A) component and other polycarboxylic acid-based dispersant), preferably 0.02 or more, more preferably 0.05 or more, and It is preferably 2 or less, more preferably 1 or less, still more preferably 0.5 or less, even more preferably 0.3 or less, even more preferably 0.2 or less, still more preferably 0.1 or less. This mass ratio includes the case where the content of one of the strength improver and the retarder is 0.

The dispersant composition for hydraulic compositions of the present invention contains, as other optional components, an AE agent, a foaming agent, a thickener, a foaming agent, a waterproofing agent, a fluidizing agent, a defoaming agent, and the like. You can

The dispersant composition for hydraulic composition of the present invention may contain water. The dispersant composition for hydraulic composition of the present invention may be a liquid composition.

The dispersant composition for hydraulic composition of the present invention may be a dispersant composition for hydraulic composition for centrifugal molding.
The dispersant composition for hydraulic composition of the present invention may be a dispersant composition for hydraulic composition for vibration molding.
The dispersant composition for a hydraulic composition for centrifugal molding is one of the preferred embodiments of the dispersant composition for a hydraulic composition of the present invention.

The present invention provides the use of the dispersant composition for hydraulic compositions of the present invention as a dispersant for hydraulic compositions for centrifugal molding or vibration molding.
The present invention also provides use of the copolymer of component (A) as a dispersant for a hydraulic composition for centrifugal molding or vibration molding.
The present invention also provides the use of the copolymer of component (A) for producing a dispersant for a hydraulic composition for centrifugal molding or vibration molding.
The matters described in the dispersant composition for a hydraulic composition of the present invention can be appropriately applied to these uses.

<Hydraulic composition>
The present invention provides a hydraulic composition for centrifugal molding or vibration molding containing the dispersant composition for hydraulic composition of the present invention, water, and hydraulic powder. The hydraulic composition of the present invention is a copolymer [(A) component] containing acrylic acid or a salt thereof, methacrylic acid or a salt thereof, and a compound represented by the following general formula (1) as constituent monomers. And water, and a hydraulic composition for centrifugal molding or vibration molding containing a hydraulic powder, wherein the copolymer is acrylic acid or a salt thereof and methacrylic acid or a salt thereof in total, acrylic acid or A hydraulic composition for centrifugal molding or vibration molding in which the proportion of the salt is 20 mol% or more and 70 mol% or less.
The matters described in the dispersant composition for a hydraulic composition of the present invention can be appropriately applied to the hydraulic composition of the present invention.

In the hydraulic composition of the present invention, the specific examples and preferred embodiments of the component (A) are the same as those of the dispersant composition for a hydraulic composition of the present invention.
From the viewpoint of dispersibility and centrifugal compaction property, the hydraulic composition of the present invention preferably contains the component (A) in an amount of 0.01 parts by mass or more, and more preferably 0 parts, relative to 100 parts by mass of the hydraulic powder. 1 part by mass or more, and preferably 9 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 1 part by mass or less.

Hydraulic powder is a powder that has the property of being hardened by a hydration reaction, and examples thereof include cement and gypsum. The hydraulic powder is preferably cement, more preferably ordinary portland cement, belite cement, moderate heat cement, early-strength cement, ultra-early-strength cement, sulfate-resistant cement and the like. In addition, blast furnace slag cement, fly ash cement, silica fume cement, etc. to which powder such as blast furnace slag, fly ash, silica fume and the like having pozzolanic action and / or latent hydraulic property, or stone powder (calcium carbonate powder) is added to cement etc. But it's okay.

The hydraulic composition of the present invention has a water / hydraulic powder ratio of preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30% by mass or less, It is more preferably 25% by mass or less. Here, the water / hydraulic powder ratio is a mass percentage (mass%) of water and the hydraulic powder in the hydraulic composition, and is calculated by mass of water / mass of hydraulic powder × 100. . The water / hydraulic powder ratio is calculated based on the amount of water and the amount of powder having physical properties that harden due to a hydration reaction. When the powder having the physical properties of being hardened by the hydration reaction includes a powder having a pozzolanic action, a powder having latent hydraulicity, and a stone powder (calcium carbonate powder), in the present invention, those powders are selected. The amount is also included in the amount of hydraulic powder. When the powder having the physical properties of being hardened by the hydration reaction contains the high-strength admixture, the amount of the high-strength admixture is also included in the amount of hydraulic powder. This also applies to the following parts by mass that relate to the mass of the hydraulic powder.

The hydraulic composition of the present invention preferably contains an aggregate. Examples of aggregates include aggregates selected from fine aggregates and coarse aggregates. As the fine aggregate, one specified by No. 2311 in JIS A0203-2014 can be mentioned. As fine aggregate, river sand, land sand, mountain sand, sea sand, lime sand, silica sand and crushed sand of these, blast furnace slag fine aggregate, ferronickel slag fine aggregate, lightweight fine aggregate (artificial and natural) and recycled Fine aggregates and the like can be mentioned. Further, as the coarse aggregate, one specified by the number 2312 in JIS A0203-2014 can be mentioned. For example, as coarse aggregate, river gravel, land gravel, mountain gravel, sea gravel, lime gravel, crushed stone of these, blast furnace slag coarse aggregate, ferronickel slag coarse aggregate, lightweight coarse aggregate (artificial and natural) and recycled Examples include coarse aggregate. Fine aggregates and coarse aggregates may be used by mixing different types, or may be used by a single type.
When the hydraulic composition is concrete, the amount of coarse aggregate used reduces the development of the strength of the hydraulic composition and the amount of hydraulic powder such as cement, and improves the filling property of the formwork etc. From the viewpoint, the bulk volume is preferably 50% or more, more preferably 55% or more, further preferably 60% or more, and preferably 100% or less, more preferably 90% or less, further preferably 80% or less. Is. The bulk volume is the ratio of the volume (including voids) of coarse aggregate in 1 m ^{3 of} concrete. Further, when the hydraulic composition is concrete, the amount of the fine aggregate used is preferably 500 kg / m ³ or more, more preferably 600 kg / m ³ or more, from the viewpoint of improving the filling property into the mold and the like. It is preferably 700 kg / m ³ or more, and preferably 1,000 kg / m ³ or less, more preferably 900 kg / m ³ or less.
When the hydraulic composition is a mortar, the amount of fine aggregate used is preferably 800 kg / m ³ or more, more preferably 900 kg / m ³ or more, even more preferably 1,000 kg / m ³ or more, and preferably Is 2,000 kg / m ³ or less, more preferably 1,800 kg / m ³ or less, and further preferably 1,700 kg / m ³ or less.

The hydraulic composition of the present invention may contain a high-strength admixture. Examples of the high-strength admixture include powders having a Blaine value of 2,500 cm ² / g or more or a BET specific surface area of 10 m ² / g or more, and inorganic powders (excluding cement). As a constituent component of the high-strength admixture, a powder selected from anhydrous gypsum, silica fume, and fly ash can be mentioned. Commercially available high-strength admixtures include Denka Σ1000 (Denka Co., Ltd.), Denka Σ2000 (Denka Co., Ltd.), and Taiheiyo Ultra Super Mix (Pacific Materials Co., Ltd.). When the hydraulic composition of the present invention contains a high-strength admixture, the content of the high-strength admixture is preferably 0.1 part by mass or more, more preferably 0.1 part by mass or more based on 100 parts by mass of hydraulic powder and cement. It is preferably 1 part by mass or more, and preferably 20 parts by mass or less, more preferably 10 parts by mass or less.

The hydraulic composition of the present invention may be a centrifugal molding hydraulic composition.
The hydraulic composition of the present invention may be a vibration molding hydraulic composition.
The hydraulic composition for centrifugal molding is one of the preferable embodiments of the hydraulic composition of the present invention.

The present invention contains the dispersant composition for a hydraulic composition for centrifugal molding or vibration molding of the present invention, water, and a hydraulic powder, and the water / hydraulic powder ratio is 10% by mass or more and 25% by mass. The use of the following composition as a hydraulic composition for centrifugal molding or vibration molding is provided.
The present invention also contains the dispersant composition for a hydraulic composition for centrifugal molding or vibration molding of the present invention, water, and a hydraulic powder, and the water / hydraulic powder ratio is 10% by mass or more and 25% or more. Provided is the use of a composition, which is less than or equal to% by weight, for producing a hydraulic composition for centrifugal molding or vibration molding.
For these uses, the matters described in the dispersant composition for hydraulic composition and the hydraulic composition of the present invention can be appropriately applied.

<Method for producing hydraulic composition>
The present invention provides a method for producing a hydraulic composition, which comprises mixing the dispersant composition for a hydraulic composition of the present invention, water, and a hydraulic powder. The method for producing a hydraulic composition of the present invention is a copolymer containing acrylic acid or a salt thereof, methacrylic acid or a salt thereof, and a compound represented by the following general formula (1) as constituent monomers [(A Component), water, and a hydraulic powder are mixed, wherein the copolymer is acrylic acid or a salt thereof and methacrylic acid or a salt thereof. A method for producing a hydraulic composition, wherein the ratio of the acid or its salt is 20 mol% or more and 70 mol% or less.
The matters described in the dispersant composition for hydraulic composition and the hydraulic composition of the present invention can be appropriately applied to the method for producing the hydraulic composition of the present invention.

In the method for producing a hydraulic composition of the present invention, specific examples and preferred embodiments of the component (A) are the same as those of the dispersant composition for a hydraulic composition of the present invention.
The specific examples and preferred embodiments of the hydraulic powder used in the method for producing the hydraulic composition of the present invention are the same as those described for the hydraulic composition of the present invention. The hydraulic powder is preferably used so that the water / hydraulic powder ratio falls within the range described in the hydraulic composition of the present invention.
Further, in the method for producing a hydraulic composition of the present invention, it is preferable to mix an aggregate. Specific examples and preferred embodiments of the aggregate are the same as those described for the hydraulic composition of the present invention. The amount of aggregate used is also the same as that described for the hydraulic composition of the present invention.

In the method for producing the hydraulic composition of the present invention, from the viewpoint of smoothly mixing the component (A) and the hydraulic powder such as cement, the component (A) and water are preliminarily mixed to obtain the hydraulic powder. Mixing is preferred.

The mixing of the hydraulic powder, water, the component (A), and the component used as necessary can be performed using a mixer such as a mortar mixer and a forced biaxial mixer.
Further, the mixture is preferably mixed for 1 minute or more, more preferably 2 minutes or more, and preferably 5 minutes or less, more preferably 3 minutes or less. In preparing the hydraulic composition, the materials, agents and their amounts described in the hydraulic composition can be used.

The obtained hydraulic composition is further filled in a mold to cure and cure. Examples of the formwork include a formwork for buildings and a formwork for concrete products. Examples of the method for filling the mold include a method of directly charging from a mixer and a method of pumping the hydraulic composition with a pump to introduce it into the mold.

When the hydraulic composition is cured, it may be cured by heating to accelerate the curing. Here, the heat curing can hold the hydraulic composition at a temperature of 40 ° C. or higher and 90 ° C. or lower to accelerate the curing.

<Method for producing cured body of hydraulic composition>
The present invention is to prepare a hydraulic composition by mixing the dispersant composition for hydraulic composition of the present invention, water, and a hydraulic powder, and fill the mold with the hydraulic composition. Provided is a method for producing a cured product of a hydraulic composition that is cured.
The method for producing a cured product of a hydraulic composition of the present invention is a copolymer containing acrylic acid or a salt thereof, methacrylic acid or a salt thereof, and a compound represented by the following general formula (1) as constituent monomers. [Component (A)], water and hydraulic powder are mixed to produce a hydraulic composition, and the hydraulic composition is filled in a mold and cured to cure the composition. The method for producing a hydraulic composition according to claim 1, wherein the copolymer has a ratio of acrylic acid or a salt thereof in the range of 20 mol% to 70 mol% in a total amount of acrylic acid or a salt thereof and methacrylic acid or a salt thereof. It is a method for producing a cured product.
The matters described in the dispersant composition for hydraulic composition, the hydraulic composition and the method for producing the hydraulic composition of the present invention can be appropriately applied to the method for producing the hydraulic composition of the present invention.

In the method for producing a cured product of the hydraulic composition of the present invention, specific examples and preferred embodiments of the component (A) are the same as those of the dispersant composition for hydraulic composition of the present invention.
The specific examples and preferred embodiments of the hydraulic powder used in the method for producing the hydraulic composition of the present invention are the same as those described for the hydraulic composition of the present invention. The hydraulic powder is preferably used so that the water / hydraulic powder ratio falls within the range described in the hydraulic composition of the present invention.
Further, in the method for producing a hydraulic composition of the present invention, it is preferable to mix an aggregate. Specific examples and preferred embodiments of the aggregate are the same as those described for the hydraulic composition of the present invention. The amount of aggregate used is also the same as that described for the hydraulic composition of the present invention.
The hydraulic composition produced by the method for producing a cured product of the present invention is preferably the hydraulic composition of the present invention.

As a method for producing a cured product of the present invention, a dispersant composition for a hydraulic composition of the present invention, water, and a hydraulic powder are mixed to produce a hydraulic composition, and the hydraulic composition is A method for producing a cured body of a hydraulic composition is described, in which the mold is filled with a centrifugal force and then the mold is clamped. This method comprises, as constituent monomers, acrylic acid or a salt thereof, methacrylic acid or a salt thereof, and a copolymer [(A) component] containing a compound represented by the following general formula (1), and water: A method for producing a cured product of a hydraulic composition, which comprises mixing a hydraulic powder to produce a hydraulic composition, filling the hydraulic composition in a mold, and then clamping the mold by applying centrifugal force. Wherein the copolymer is a cured product of a hydraulic composition in which the proportion of acrylic acid or a salt thereof in the total of acrylic acid or a salt thereof and methacrylic acid or a salt thereof is 20 mol% or more and 70 mol% or less. This is a manufacturing method (hereinafter referred to as a centrifugal method). The centrifugal method is what is called centrifugal compaction molding.

Further, as a method for producing a cured product of the present invention, a hydraulic composition is produced by mixing a dispersant composition for a hydraulic composition of the present invention, water, and a hydraulic powder, and the hydraulic composition A method for producing a cured product of a hydraulic composition, in which a product is filled in a mold and then the mold is clamped by applying vibration, can be mentioned. This method comprises, as constituent monomers, acrylic acid or a salt thereof, methacrylic acid or a salt thereof, and a copolymer [(A) component] containing a compound represented by the following general formula (1), and water: A method for producing a cured body of a hydraulic composition, which comprises mixing a hydraulic powder to produce a hydraulic composition, filling the hydraulic composition in a mold, and then clamping with vibration. The copolymer is a cured product of a hydraulic composition in which the proportion of acrylic acid or a salt thereof in the total of acrylic acid or a salt thereof and methacrylic acid or a salt thereof is 20 mol% or more and 70 mol% or less. Method (hereinafter referred to as vibration method). The vibration method is what is called vibration compaction molding.

In the present invention, the method of adding the mixture containing water and the component (A) to the aggregate and the hydraulic powder and mixing the mixture is easy and uniform even when the hydraulic composition is produced. preferable.

The hydraulic composition may be prepared by mixing the hydraulic powder and the aggregate, adding a mixture containing water and the component (A) so that the mixture amount is as described above, and kneading. it can.

A mold suitable for the centrifugal method and the vibration method is appropriately selected in consideration of the use of the cured body of the hydraulic composition. The filling of the hydraulic composition into the mold can be performed by a known method.
Examples of the method of filling the obtained hydraulic composition in a mold include a method in which the hydraulic composition after kneading is discharged from the kneading means and manually charged into the mold.

In the centrifugal method, the hydraulic composition for centrifugal molding filled in a mold is subjected to centrifugal force to clamp the mold.
At this time, it is preferable to change the centrifugal force at least once. In the present invention, the hydraulic composition for centrifugal molding can be clamped by applying a gradually changing centrifugal force. That is, in the present invention, the hydraulic composition for centrifugal molding is clamped at least once by changing the centrifugal force, and further, it is clamped by applying a centrifugal force that changes stepwise and increases stepwise. You can

In the centrifugal method, it is preferable to clamp the hydraulic composition filled in the mold with a centrifugal force of 0.5 G or more. The centrifugal force of centrifugal molding is preferably 0.5 G or more and 30 G or less, more preferably 25 G or less. From the viewpoint of energy cost reduction and moldability, it is preferable to keep the centrifugal force in the range of 15 minutes or more, 30 G or less, and further 25 G or less (also referred to as high centrifugal force) for 1 minute or more.

The compaction by centrifugal force is, for example, 0.5 G or more and 30 G or less, preferably 5 minutes or more, more preferably 7 minutes or more, further preferably 9 minutes or more, and preferably 40 minutes or less. From the viewpoint of compacting the molded body smoothly, compaction by maintaining a high centrifugal force, for example, a centrifugal force of 20 G or more, is preferably 1 minute or more, more preferably 3 minutes or more, further preferably 5 minutes or more, and preferably Do less than 15 minutes. That is, in the present invention, the centrifugal force of 0.5 G or more and 30 G or less is applied to the hydraulic composition over 5 minutes or more, more preferably 7 minutes or more, further preferably 9 minutes or more, and preferably 40 minutes or less. You can clamp things. Further, in the present invention, compaction by holding a centrifugal force of 20 G or more can be performed for preferably 1 minute or more, more preferably 3 minutes or more, further preferably 5 minutes or more, and preferably 15 minutes or less.

Compaction by centrifugal force can be performed in stages, and from the viewpoint of moldability, it is preferable to increase the centrifugal force G stepwise. It can be carried out under the following stage conditions until the desired centrifugal force is achieved. For example, in the case of five stages, according to the present invention, (1) the initial velocity of the first stage is 0.5 G or more and less than 2 G, and the centrifugal force of more than 0 minutes and 15 minutes or less, and (2) the second stage of the second stage is 2 G Centrifugal force of 5G or more and more than 0 minutes and 15 minutes or less, (3) third speed, which is the third stage, is 5G or more and less than 10G, more than 0 minutes and 15 minutes or less, and (4) fourth stage, the fourth speed Is 10 G or more and less than 20 G with a centrifugal force of more than 0 minutes and 15 minutes or less, and (5) the fifth stage is a centrifugal force of 20 G or more and 30 G or less with a centrifugal force of more than 0 minutes and 15 minutes or less. It is preferable to perform mold clamping.

In the centrifugal method, it is preferable to heat-cure the hydraulic composition after clamping the mold by applying a centrifugal force.

Heat curing is preferably performed at 75 ° C or higher, and preferably 100 ° C or lower, more preferably 90 ° C or lower. The heating and curing may include a step of holding at 75 ° C. or higher for 1 hour or longer. The temperature of heating and curing is the temperature of the atmosphere around the mold filled with the hydraulic composition.

When the mold is clamped by applying a centrifugal force, from the viewpoint of slump loss, the ambient temperature (ambient temperature of the mold) is preferably 35 ° C. or lower, more preferably 30 ° C. or lower, more preferably 25 ° C. or lower, and strength developability. From this viewpoint, the temperature is preferably 10 ° C or higher, more preferably 15 ° C or higher, and further preferably 20 ° C or higher.

In the present invention, it is preferable to carry out low temperature curing for 1 hour or more, starting from the point of time when water first contacts the hydraulic powder during the mixing, before starting the heating curing.
The low temperature curing is preferably performed at 0 ° C or higher, more preferably 10 ° C or higher, and preferably 40 ° C or lower, more preferably 30 ° C or lower.
The low temperature curing is preferably carried out for 1 hour or longer, more preferably 2 hours or longer, and preferably 5 hours or shorter, more preferably 4 hours or shorter.

In the present invention, it is preferable that the heating curing is performed by steam curing. The steam curing is performed, for example, by applying steam around the mold filled with the centrifugally-molded hydraulic composition and maintaining it at a predetermined temperature for a certain period of time.

After heating and curing, the hydraulic composition can be cooled and released from the mold. In addition, the cured body of the demolded hydraulic composition can be cured at room temperature and atmospheric pressure.
For example, immediately after heating and curing, for example, the ambient temperature may be cooled to room temperature, for example, 20 ° C., or the ambient temperature may be room temperature, for example, 20 ° C. at a temperature decreasing rate of 5 ° C. or more and 20 ° C. or less per hour. You may cool down to. After cooling, the molded body is released from the mold. The rate of temperature decrease is preferably 20 ° C. or less per hour from the viewpoint of suppressing a decrease in strength due to cracking of the cured body. Further, the cured product of the obtained hydraulic composition can be cured at room temperature and atmospheric pressure. Specifically, it can be stored at 20 ° C. under atmospheric pressure.

The hardened product of the hydraulic composition obtained by the centrifugal method can be used as a centrifugally molded concrete product, and specific examples thereof include piles, poles, and fume tubes. The hardened product of the hydraulic composition obtained by the centrifugal method has excellent compaction properties, so that the inner surface and end surface irregularities of the product are small, the surface aesthetics are excellent, and the inner surface of the product is finished smoothly. The obstacles of the cutting machine during the Nakabori method are improved.

The vibration method involves filling the mold with the hydraulic composition used to manufacture the cured product, and vibrating the hydraulic composition in the mold. Hereinafter, the operation of applying vibration to the hydraulic composition is also referred to as vibration molding.

Vibration molding can be performed at a frequency of 20 Hz to 350 Hz, for example. Further, the vibration molding can be performed in, for example, 3 seconds or more and 180 seconds or less. When the mold cannot be sufficiently filled by one filling, when filling the additional hydraulic composition, even if vibration of the previous hydraulic composition is stopped or continued to be applied, either Good.

As an example of a method for producing a cured product of the hydraulic composition of the present invention, a method for producing a cured product of a hydraulic composition containing a polycarboxylic acid-based dispersant, hydraulic powder and water, A method for producing a cured product of a hydraulic composition, in which vibration is applied after filling the composition with a mold, can be mentioned.

Another example of the method for producing a cured product of the hydraulic composition of the present invention is a method for producing a cured product of a hydraulic composition containing a polycarboxylic acid-based dispersant, hydraulic powder and water. Then, a method for producing a cured product of a hydraulic composition, in which a hydraulic composition used for producing a cured product is filled in a mold and the hydraulic composition in the mold is vibrated, can be mentioned.

By using the dispersant composition for hydraulic composition of the present invention, the moldability during vibration molding can be improved. According to the present invention, there is provided a method for improving the moldability of a hydraulic composition in a vibration molding step using the dispersant composition for a hydraulic composition of the present invention.

By using the dispersant composition for hydraulic composition of the present invention, it is possible to improve compaction property of the hydraulic composition by centrifugal force during centrifugal molding. According to the present invention, there is provided a method for improving the compaction property of a hydraulic composition by centrifugal force, using the dispersant composition for a hydraulic composition of the present invention.

By using the dispersant composition for hydraulic composition of the present invention, the strength of the cured product of the hydraulic composition is improved. The present invention provides a method for improving the strength of a cured product of a hydraulic composition using the dispersant composition for a hydraulic composition of the present invention.

Example <(A) component>
Hereinafter, the constitution of the copolymer will be shown with acrylic acid or its salt as AA, methacrylic acid or its salt as MAA, and the compound represented by the general formula (1) as compound (1). Further, the ratio (mol%) of acrylic acid or a salt thereof in the total of acrylic acid or a salt thereof and methacrylic acid or a salt thereof is shown as an AA ratio.
Copolymer 1: AA / MAA / Compound (1) = sodium acrylate / sodium methacrylate / methoxy polyethylene glycol (45) monomethacrylate (average number of moles in parentheses of the monomer, the same applies hereinafter) = 29 mol% / 45 mol% / 26 mol%, weight average molecular weight = 30,000, AA ratio is 39 mol%
Copolymer 2: AA / MAA / Compound (1) = sodium acrylate / sodium methacrylate / methoxy polyethylene glycol (45) monomethacrylate = 31 mol% / 44 mol% / 25 mol%, weight average molecular weight = 37,000, AA ratio Is 41 mol%
Copolymer 3: AA / MAA / Compound (1) = sodium acrylate / sodium methacrylate / methoxypolyethylene glycol (50) monomethacrylate = 35 mol% / 35 mol% / 30 mol%, weight average molecular weight = 35,000, AA ratio Is 50 mol%
Copolymer 4: AA / MAA / Compound (1) = sodium acrylate / sodium methacrylate / methoxy polyethylene glycol (45) monomethacrylate = 51 mol% / 22 mol% / 27 mol%, weight average molecular weight = 30,000, AA ratio Is 70 mol%

<Other polycarboxylic acid type dispersants>
Copolymer 5: MAA / compound (1) = sodium methacrylate / methoxy polyethylene glycol (25) monomethacrylate = 75 mol% / 25 mol%, weight average molecular weight = 50,000, AA ratio is 0 mol%
Copolymer 6: MAA / compound (1) = sodium methacrylate / methoxypolyethylene glycol (45) monomethacrylate = 75 mol% / 25 mol%, weight average molecular weight = 57,000, AA ratio is 0 mol%
Copolymer 7: AA / other monomer = sodium acrylate / polyethylene glycol (45) monoisoprenyl ether = 75 mol% / 25 mol%, weight average molecular weight = 46,000, AA ratio is 100 mol% (constituting unit amount Does not contain the compound (1) as a body)
Copolymer 8: AA / MAA / Compound (1) = sodium acrylate / sodium methacrylate / methoxy polyethylene glycol (45) monomethacrylate = 50 mol% / 30 mol% / 20 mol%, weight average molecular weight = 28,000, AA ratio Is 63 mol%

<Example 1 and Comparative Example 1>
(1) Mortar formulation The mortar formulation is shown below. P is the total mass of cement (abbreviation C) and high-strength admixture (abbreviation A), and W / P (= C + A) is the ratio of water / hydraulic powder (mass%).

* Cement with mortar (C): 800 g (1: 1 mixture of early strength Portland cement manufactured by Taiheiyo Cement Co., Ltd. and early strength Portland cement manufactured by Sumitomo Osaka Cement Co., Ltd., specific gravity 3.16)
High-strength admixture (A): 64 g (manufactured by Denki Kagaku Kogyo Co., Ltd., specific gravity 2.45)
Tap water (W): 171 g (including copolymer or dispersant)
W / P: 20 mass%
Sand (S): 1195g (produced by Joyo, Kyoto Prefecture, specific gravity 2.50)
In addition, all the materials were adjusted to 20 ° C., and the amount of the copolymer or the dispersant in tap water was a minute amount relative to the mortar formulation, so the W / P was calculated by including it in the amount of tap water.

(2) Preparation of mortar A composition containing a copolymer ((A) component or other polycarboxylic acid-based dispersant) and water was prepared so that the addition amount was as shown in Table 1. The copolymer was used in the addition amount shown in Table 1. The composition was added to water (W) of the mortar compounding material and prepared together with other mortar compounding materials. The mortar was prepared by kneading the compounding components (60 rpm, 540 seconds) using a mortar mixer specified by JIS R5201.

(3) Evaluation of centrifugal compaction property of mortar (I)
The mortar prepared by the method of (2) was sampled in an aluminum container of 400 mL in an amount of 750 g, and the standard rod described in JIS R 5201 cement physical test method 9.2.1 Vicat needle device, 9.2.1 b) (effective). Using a cylindrical non-corrosive metal with a length of 45 mm or more and a diameter of 10.0 ± 0.2 mm), following the physical test method of JIS R 5201 cement, 9.4.3 "Measurement of initial and final setting of setting" The mortar centrifugal compaction property was evaluated by the situation when the standard rod was lowered into the mortar. Specifically, within 10 seconds immediately after preparing the mortar, the standard rod is gradually lowered from near the surface of the mortar by its own weight, and the indentation length of the standard rod into the mortar at the time when the mortar stops is measured immediately after the mortar is prepared. The standard indentation depth of In addition, the standard rod is gradually lowered from near the surface of the mortar to the surface of the mortar at intervals of 10 seconds after the first standard rod is lowered, and when the lowering is stopped, the distance between the tip of the standard rod and the bottom plate is 0.1 mm. It was read and recorded in units, and the time until the distance between the tip of the standard rod and the bottom plate remained unchanged three times was measured. The results are shown in Table 1.

(4) Evaluation of centrifugal compaction of mortar (II)
From the result of the evaluation (I) of the centrifugal compaction property of the mortar, it is considered that in this evaluation system, the larger the penetration depth immediately after the mortar preparation is, the more the mortar is fluidized and the filling property of the aggregate is improved. Immediately after the indentation depth (P; mm) of the standard rod, the "fillability" is determined by the time (t; sec) immediately after the mortar preparation until the distance between the tip and the bottom plate of the standard rod does not change three consecutive times. ), It is possible to evaluate the "shape retention" (the shorter the time required to develop the shape retention, the less likely defects such as shelving) will occur, and the P / t in the following calculation formula (I) will be centrifugally tightened. It was evaluated as an index of firmness. It can be judged that the centrifugal compaction property is better as the value of P / t is larger. In this evaluation, the value of P / t is preferably 0.015 or more. The results are shown in Table 1.
Centrifugal compactability = P / t Formula (I)
P: Depth of depth of standard bar immediately after mortar preparation (mm)
t: Time (sec) required from the preparation of mortar until the indentation depth of the standard rod does not change three times in a row

In the table, the AA ratio is the ratio (mol%) of AA in the total of AA and MAA.
In the table, Mw is a weight average molecular weight.
In the table, EOp is the average number of moles of ethylene oxide added, and corresponds to n in the general formula (1).
In the table, the addition amount is a mass part in terms of effective components with respect to 100 mass parts of the hydraulic powder (cement and high-strength admixture) (hereinafter the same).
In the table, "standard bar depth" is the standard bar depth immediately after mortar preparation.
In the table, the "invariant time of indentation depth" is the time until the distance between the tip of the standard rod and the bottom plate does not change three consecutive times.
In the table, "Dispersant A" is a dispersant having the following composition (the same applies hereinafter).
Copolymer 1 / copolymer 5 / glycerin / sodium gluconate = 80/14/4/2 (mass ratio)

In Table 1, as compared with Comparative Examples 1-1 and 1-2 using a copolymer containing no AA as a constituent monomer and Comparative Example 1-3 containing no compound (1), a constituent monomer was used. Examples 1-1 to 1-5 using the copolymer containing a predetermined amount of AA showed excellent centrifugal compaction property. It is considered that this is because the copolymers of Examples had a flexible molecular structure, promoted hydration of cement particles, and exhibited high retention due to the network structure of the hydration product. It is also found that Comparative Examples 1-4 using a copolymer having a weight average molecular weight outside the range of the present invention are inferior in centrifugal compaction property as compared with Examples.

<Example 2 and Comparative Example 2>
(1) Mortar formulation The mortar formulation is shown below. P is the total mass of cement (abbreviation C) and high-strength admixture (abbreviation A), and W / P (= C + A) is the ratio of water / hydraulic powder (mass%).

* Cement with mortar (C): 800 g (1: 1 mixture of early strength Portland cement manufactured by Taiheiyo Cement Co., Ltd. and early strength Portland cement manufactured by Sumitomo Osaka Cement Co., Ltd., specific gravity 3.16)
High-strength admixture (A): 64 g (manufactured by Denki Kagaku Kogyo Co., Ltd., specific gravity 2.45)
Tap water (W): 209 g (including copolymer)
W / P: 24 mass%
Sand (S): 1195g (produced by Joyo, Kyoto Prefecture, specific gravity 2.50)
In addition, all the materials were adjusted to 20 ° C., and the amount of the copolymer in tap water was a minute amount relative to the mortar formulation, so the W / P was calculated by including it in the amount of tap water.

(2) Preparation of Mortar A composition containing a copolymer ((A) component or other polycarboxylic acid-based dispersant) and water was prepared so that the addition amount was as shown in Table 2. The composition was added to water (W) of the mortar compounding material and prepared together with other mortar compounding materials. The mortar was prepared by kneading the compounding components (60 rpm, 540 seconds) using a mortar mixer specified by JIS R5201. The copolymer was used in the addition amount shown in Table 2.

(3) Method of measuring mortar rheology The mortar prepared by the method of (2) was sampled in an aluminum container of 400 mL by 750 g, and rheology was measured using the rheometer Physica MCR301 manufactured by Anton Paar under the following measurement conditions.
<Thixoloop measurement>
Jig: Ball type, d = 8 (mm)
Number of measurement points: 20 points Measurement interval: 10 (sec.)
Shear rate: 0.004-4 (1 / sec.)

(4) Evaluation method of mortar rheology Based on the measurement result of mortar rheology measured by the method of (3), from the consideration on the centrifugal compaction property of the concrete, the more the thixotropic property of the mortar is improved, the more the centrifugal compaction property is improved. Considering that it improves, the hysteresis (ΔH; Pa / s) that is an index of thixotropic property was calculated based on the following formula (II). It can be judged that the larger the value of hysteresis is, the more excellent the thixotropy is. In this evaluation, the hysteresis value is preferably 4000 or more. The results are shown in Table 2.
Hysteresis (ΔH; Pa / s) = ∫ {f (x) -g (x)} dx ... Formula (II)
f (x): approximate expression under rising shear conditions g (x): approximate expression under falling shear conditions

In Table 2, as compared with Comparative Examples 2-1 to 2-2 using a copolymer containing no AA as a constituent monomer and Comparative Example 2-3 containing no compound (1), a constituent monomer was used. Examples 2-1 to 2-4 using the copolymer containing a predetermined amount of AA showed large hysteresis and thixotropy. This is because the copolymer of the example has a flexible molecular structure under the conditions of increasing shear, which promotes the hydration of cement particles, and as a result, the network structure of the formed hydration product shows high shear stress. It is considered that the shear stress was reduced due to the destruction of the network structure by shearing under the falling shearing condition. It is also found that Comparative Example 2-4 using a copolymer having a weight average molecular weight outside the range of the present invention has smaller hysteresis and thixotropy as compared with the Examples.

<Example 3 and Comparative Example 3>
(1) Concrete mix The concrete mix is shown below. P is the total mass of cement (abbreviation C) and high-strength admixture (abbreviation A), and W / P (= C + A) is the ratio of water / hydraulic powder (mass%).

* Concrete mix 1
Cement (C): 12.6 kg (early strength Portland cement manufactured by Taiheiyo Cement Co., Ltd., specific gravity 3.16)
High-strength admixture (A): 1.0 kg (Denki Kagaku Kogyo Co., Ltd., specific gravity 2.45)
Tap water (W): 2.7 kg (including copolymer)
W / P: 20 mass%
Sand (S): 18.9 kg (from Koga, Shiga prefecture, specific gravity 2.58)
Gravel (G): 28.4 kg (Ieshima, Hyogo, specific gravity 2.63)
In addition, all the materials were adjusted to 20 ° C., and the amount of the copolymer in tap water was a minute amount relative to the mortar formulation, so the W / P was calculated by including it in the amount of tap water.

* Concrete mix 2
Cement (C): 11.1 kg (ordinary Portland cement manufactured by Taiheiyo Cement Co., Ltd., specific gravity 3.16)
High-strength admixture (A): 0.3 kg (Denki Kagaku Kogyo Co., Ltd., specific gravity 2.45)
Tap water (W): 2.9 kg (including copolymer)
W / P: 25 mass%
Sand (1) (S (1)): 9.4kg (produced by Ibigawa, Gifu prefecture, specific gravity 2.55)
Sand (2) (S (2)): 10.3 kg (from Koga, Shiga prefecture, specific gravity 2.58)
Gravel (G): 28.4 kg (Ieshima, Hyogo, specific gravity 2.63)
In addition, all the materials were adjusted to 20 ° C., and the amount of the copolymer in tap water was a minute amount relative to the mortar formulation, so the W / P was calculated by including it in the amount of tap water.

(2) Preparation of concrete A composition containing a copolymer and water was prepared so that the addition amounts shown in Table 3 were obtained. The copolymer was used in the addition amount shown in Table 3. The composition was added to water (W) of the concrete compounding material and stirred to prepare. For concrete, in a forced twin-screw mixer (manufactured by KYC), gravel, about half the amount of sand, a mixture of early-strength cement and high-strength admixture, and the balance of sand were added in that order, and kneading was carried out for 30 seconds, then, The water prepared above was quickly added, and the mixture was kneaded for 240 seconds to obtain concrete.

(3) Evaluation of Centrifugal Compactability Concrete 10 minutes after kneading is put into a centrifugal molding form (inner diameter 20 cm, outer diameter 25 cm, height 40 cm), initial speed is 1 G for 2 minutes, and second speed is 3 G. Centrifugal compaction was carried out under the conditions of 3 minutes, 7G for 2 minutes, 4th speed for 15G for 3 minutes, and 5th speed for 25G for 3 minutes. A simple test of penetrating a finger was carried out on the tubular molded body that had been subjected to centrifugal compaction, and the centrifugal compactibility was evaluated on a scale of 1 to 5 based on the following evaluation criteria. The results are shown in Table 3.

<Evaluation criteria for centrifugal compaction>
1: Even if the amount of the copolymer or dispersant added is adjusted, obvious molding defects such as sludge and junkers occur.
2: Although no obvious molding failure occurs, sludge adheres only by touching the inner surface of the molded body because the end face has poor filling properties or the molded body is soft.
3: No defective molding occurs, and the end face filling property is good, but it easily penetrates when the index finger is pressed against the inner surface of the molded product.
4: No defective molding occurred, the end face was well filled, and no penetration easily occurred even when the index finger was pressed against the inner surface of the molded product to press it.
5: No defective molding occurs, the end face filling property is good, and no penetration occurs even when the index finger is pressed against the inner surface of the molded body by pushing.
In these evaluations, when the plate of the balance was pressed with the index finger with the same force as the force for pushing the inner surface of the molded body with the index finger, the contact surface of the finger was a circle with a diameter of about 1 cm, and the scale of the balance was 500 g. It was

In Table 3, a predetermined amount of AA was used as a constituent monomer for Comparative Example 3-1 using a copolymer not containing AA as a constituent monomer and Comparative Example 3-2 containing no compound (1). Examples 3-1a to 3-1e and Example 3-2 using the copolymers containing them showed good centrifugal compaction properties. This means that, at the end of molding, the copolymers of Examples showed a high yield value due to the network structure of the formed hydration product as a result of the hydration of cement particles being promoted by the flexible molecular structure, and the centrifugal force. It is considered that this is because the concrete was fluidized due to the rattling accompanying the rotation of the metal mold during the molding, and the filling property of the mortar component into the aggregate gap was improved.

Claims (21)

1. Acrylic acid or a salt thereof, methacrylic acid or a salt thereof, and a compound represented by the following general formula (1) are included as constituent monomers. Alternatively, a dispersant composition for a hydraulic composition for centrifugal molding or vibration molding, which contains a copolymer having a salt content of 20 mol% or more and 70 mol% or less and a weight average molecular weight of 30,000 or more and 100,000 or less. .
   

   

   (In the formula, R ¹ and R ³ are the same or different and represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² represents a hydrogen atom or a methyl group, and n is an average number of moles added and is 5 or more. Indicates a number of 150 or less.)
2. The copolymer has a ratio of the total amount of acrylic acid or a salt thereof and methacrylic acid or a salt thereof in the total of acrylic acid or a salt thereof, methacrylic acid or a salt thereof, and the compound represented by the general formula (1). The dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to claim 1, which is 50 mol% or more and 95 mol% or less.
3. The dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to claim 1 or 2, wherein n is a number of 10 or more and 90 or less in the general formula (1).
4. The dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to any one of claims 1 to 3, further comprising a strength improver and / or a retarder.
5. The dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to claim 4, wherein the strength improver is one or more selected from polyol compounds.
6. The dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to claim 4 or 5, wherein the strength improver is glycerin.
7. The dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to any one of claims 4 to 6, wherein the retarder is one or more selected from oxycarboxylic acids.
8. The dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to any one of claims 4 to 7, wherein the retarder is gluconic acid and / or a salt thereof.
9. 9. The mass ratio between the content of the copolymer and the content of the strength improver is 0.01 or more and 1 or less (strength improver content / copolymer content). The dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to item 1.
10. 10. The mass ratio between the content of the copolymer and the content of the retarder is 0.01 or more and 1 or less, in terms of the content of the retarder / the content of the copolymer, 1 to 9. Item 10. A dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to item.
11. The dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to any one of claims 1 to 10, which further contains a polycarboxylic acid-based dispersant composed of a copolymer other than the copolymer.
12. The mass ratio of the total content of the strength improver and the retarder and the total content of the copolymer and the polycarboxylic acid-based dispersant is (total content of the strength improver and the retarder) / (the above-mentioned copolymer The centrifugal molding or vibration molding water according to claim 11, wherein the total content of the polymer and the polycarboxylic acid dispersant is 0.02 or more and 2 or less. A dispersant composition for a hard composition.
13. The dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to any one of claims 1 to 12, which is for centrifugal molding.
14. A centrifugal-molding or vibration-molding dispersant composition for hydraulic composition according to any one of claims 1 to 13, water and hydraulic powder, and a water / hydraulic powder ratio of 10 mass. % Or more and 25 mass% or less, hydraulic composition for centrifugal molding or vibration molding.
15. The hydraulic composition for centrifugal molding or vibration molding according to claim 14, which is for centrifugal molding.
16. A method for improving compaction property of a hydraulic composition by centrifugal force, using the dispersant composition for hydraulic composition for centrifugal molding or vibration molding according to any one of claims 1 to 13.
17. A method for producing a hydraulic composition, which comprises mixing the dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to any one of claims 1 to 13, water and hydraulic powder.
18. A hydraulic composition is produced by mixing the dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to any one of claims 1 to 13, water, and a hydraulic powder to prepare the hydraulic composition. A method for producing a cured product of a hydraulic composition, which comprises filling a mold composition with the hard composition and then clamping the mold by applying a centrifugal force.
19. A hydraulic composition is produced by mixing the dispersant composition for a hydraulic composition for centrifugal molding or vibration molding according to any one of claims 1 to 13, water, and a hydraulic powder to prepare the hydraulic composition. A method for producing a cured product of a hydraulic composition, which comprises filling a mold composition with the hard composition and then clamping the mold by applying vibration.
20. Use of the composition according to any one of claims 1 to 13 as a dispersant for a hydraulic composition for centrifugal molding or vibration molding.
21. A centrifugal-molding or vibration-molding dispersant composition for hydraulic composition according to any one of claims 1 to 13, water and hydraulic powder, and a water / hydraulic powder ratio of 10 mass. % Or more and 25% by mass or less, as a hydraulic composition for centrifugal molding or vibration molding.