JP7039280B2 - SCM miscible material high content admixture for concrete, and admixture-containing composition and cement composition containing this - Google Patents

Description

The present invention relates to an admixture for use in concrete containing a high content of SCM admixture, particularly a chemical admixture for concrete. The present invention also relates to an admixture-containing composition and a cement composition containing such an admixture.

Cement, water, fine aggregate, coarse aggregate and the like are usually used in the cement composition containing cement such as concrete, and an admixture such as blast furnace slag, silica fume and fly ash is blended as needed. Such admixtures have latent hydraulic or pozzolanic activity, and are generally collectively referred to as SCM (Supplementary Cementitious Materials) admixtures as auxiliary cement substances to be blended in concrete.

The SCM admixture is a substance that is hardened by latent hydrohardness or pozzolan activity by the stimulation of alkali, and is in the form of being mixed with cement in advance, such as blast furnace slag cement, silica cement, and fly ash cement, or a separately SCM admixture. Has been conventionally used as a cement mixing material in the form of mixing with cement.

By blending such an SCM admixture into cement, excellent effects such as suppression of heat of hydration, improvement of watertightness, suppression of alkali-silica reaction, and suppression of permeation of chloride ions are expected. The specifications of the SCM admixture are specified in the JIS standard, and in the JIS R 5211: 2009, JIS R 5212: 2009, and JIS R 5213: 2009 standards, types A and B are based on the amount to be blended in the cement. , C type. Blast furnace slag has an upper limit of 70% by mass, silica has an upper limit of 30% by mass, and fly ash has an upper limit of 30% by mass with respect to the cement mass.

However, most of the SCM admixtures actually used as the SCM admixture to be blended in cement are blast furnace slag type B (the amount of blast furnace slag exceeds 30% by mass and 60% by mass or less), and such SCM. Its use is avoided due to the disadvantages of blending admixtures, such as delayed coagulation, accelerated neutralization, loss over time, quality stability, and high cost. Although the delay in condensation can be alleviated to some extent by the addition of an early-strength material or an alkaline stimulant, the problem of loss over time has not been solved.

On the other hand, in recent years, for the purpose of effective utilization of industrial waste and reduction of environmental load, SCM admixture should be used more positively in order to replace cement or assist the hydraulic hardness of cement, for example, in 2013. It is being examined by the Japan Concrete Engineering Society by the "Research Committee on Evaluation and Construction of Impact on Concrete Performance by Active Use of Admixtures" (Non-Patent Document 1). From the viewpoint of further effective utilization of industrial waste, it is required to use the SCM miscible material at a high ratio near or above the upper limit of the mixing ratio. Further, when the curing action is insufficient by the alkaline stimulation of cement, a method of separately adding an alkaline stimulating material such as water glass to cure the cement has been attempted.

The blending of these SCM miscible materials does not affect the workability or has the effect of improving the workability in the amount of the above JIS standard B type, but the fluidity and the state of the concrete with the elapsed time. It is said that (the property that fresh concrete has an appropriate viscosity and the materials do not separate and flow together, hereinafter simply referred to as "state") tends to decrease. On the other hand, it has been reported that such a tendency becomes remarkable when a large amount of SCM admixture is used. In particular, when fly ash is used, the amount of dispersant added is generally small, but the viscosity of concrete becomes high due to the decrease in fluidity over time, which makes handling and filling difficult. Is known (Non-Patent Document 2).

When such an SCM admixture is blended into concrete at a high content, various additives for adjusting the characteristics required according to the purpose of use as well as appropriately adjusting the blending of the concrete material, For example, an admixture (dispersant) is used. Non-Patent Document 3 describes the use of a polycarboxylic acid-based dispersant having a specific chemical structure in concrete containing blast furnace slag at a high content. In Non-Patent Document 3, Ca ²⁺ ions supplied from cement are specifically adsorbed on the blast furnace slag to form adsorption sites. Therefore, in concrete containing only cement and concrete containing blast furnace slag, the adsorption behavior of the dispersant and the like. It suggests that the dispersion behavior is different. It is also suggested in Non-Patent Document 3 that these adsorption behaviors and dispersion behaviors are affected by the chemical structure of the dispersant. However, there is no mention of the relationship between the type of dispersant and its chemical structure and the fluidity and state of concrete containing a high content of SCM admixture over time.

Research Committee Report on Impact Assessment and Construction of Concrete Performance by Active Use of Admixtures, Japan Concrete Engineering Society, August 2013 JCI Annual Conference 1999, Vol.21, No.2, p115-120 Proceedings of Cement and Concrete, "Adsorption Behavior of Polymer Dispersants on Cement with High Blast Furnace Slag" 2011, Vol.65, p27-32

The present invention is an admixture capable of suppressing a decrease in fluidity and state with elapsed time even when used for concrete containing a large amount of SCM admixture, and an admixture-containing composition and cement containing the admixture. It is an object of the present invention to provide a composition.

As a result of diligent research to solve the above problems, the present inventors have used an admixture containing a polycondensate having a specific structural unit in concrete containing a large amount of SCM admixture. It has been found that an admixture capable of suppressing a decrease in fluidity and state with elapsed time, and an admixture-containing composition and a cement composition containing the admixture can be obtained.

That is, the gist structure of the present invention is as follows.
[1] Condensing a polycondensate having at least one structural unit (I), at least one structural unit (II), and at least one structural unit (III).
The structural unit (I) is an aromatic moiety having a polyether side chain having an alkylene glycol unit, however, the number of ethylene glycol units in the polyether side chain is 9 to 41, and the ethylene glycol. The content of the unit is more than 80 mol% with respect to all the alkylene glycol units in the polyether side chain.
The structural unit (II) is an aromatic moiety having at least one phosphate ester group and / or a salt thereof, provided that the value of the molar ratio of the structural unit (I) to the structural unit (II) is , 0.3-4,
The structural unit (III) is at least one methylene unit (-CH _2- ), and the methylene unit is bound to two aromatic structural units, the structural unit (I) and the structural unit (II). Here, the aromatic structural units are independent of each other, the same or different, and
An admixture for concrete containing a high amount of SCM admixture, wherein the mass average molecular weight Mw of the polycondensate containing the structural units (I), (II) and (III) is in the range of 3,000 to 50,000.
[2] The polycondensate further has at least one structural unit (IV).
The structural unit (IV) is represented by an aromatic structural unit different from the structural unit (I) and the structural unit (II).
The methylene unit is bound to three aromatic structural units, that is, the structural unit (I), the structural unit (II), and the structural unit (IV), where the aromatic structural units are independent of each other. And they are the same or different, and
The above-mentioned [1], wherein the mass average molecular weight Mw of the polycondensate containing the structural units (I), (II), (III) and (IV) is in the range of 3,000 to 50,000. Admixture.
[3] The admixture according to the above [1] or [2], further comprising a retention aid.
[4] The above-mentioned [3], wherein the retention aid is a copolymer obtained by polymerizing a hydrolyzable monomer, an ethylenically unsaturated monomer containing a polyoxyalkylene group, and a cement-adsorbing monomer. The admixture described in.
[5] The above-mentioned [5], wherein the retention aid is a copolymer obtained by polymerizing a hydrolyzable monomer and an ethylenically unsaturated monomer containing a polyoxyalkylene group without containing a cement-adsorbing monomer. 3] The admixture according to.
[6] The admixture according to any one of the above [1] to [5], further comprising a retarder selected from the group consisting of oxycarboxylic acid, oxycarboxylate, saccharides and sugar alcohols. ..
[7] Any of the above [1] to [6], which is applied to SCM admixture high-containing concrete containing blast furnace slag as the SCM admixture and having a replacement ratio of the blast furnace slag with cement exceeding 60%. The admixture described in one.
[8] Any of the above [1] to [6], which is applied to concrete containing a high amount of silica fume as an SCM miscible material and having a substitution rate of the silica fume with respect to cement of more than 20%. The admixture described in one.
[9] Any of the above [1] to [6], which is applied to concrete containing a high amount of fly ash as an SCM miscible material and having a replacement rate of the fly ash with respect to cement of more than 20%. The admixture described in one.
[10] An admixture-containing composition containing the admixture according to any one of the above [1] to [9] and CSH-based fine particles as a curing accelerator.
[11] A cement composition containing the admixture according to any one of the above [1] to [9].

By using the admixture according to the present invention in concrete containing a large amount of SCM admixture, it is possible to suppress deterioration of fluidity and state with elapsed time. Therefore, it is possible to maintain the workability of concrete and extend the pot life.

Hereinafter, embodiments of the present invention will be described in detail. In the following, the numerical range represented by using "-" means a range including the numerical values before and after "-" as the lower limit value and the upper limit value.

(Concrete with high content of SCM miscible material)
In the present invention, the concrete containing a large amount of SCM admixture means concrete having a large amount of SCM admixture (auxiliary cement substance having latent hydraulic property or pozzolan activity) to be blended in the cement, and specifically, JIS. It means concrete containing SCM admixture that belongs to Class C or exceeds the upper limit of the amount specified in Class C in the standards of R 5211: 2009, JIS R 5212: 2009, and JIS R 5213: 2009. For example, in blast furnace slag, the amount of blast furnace slag blended in cement is more than 60% by mass, in silica fume, the amount of silica fume blended in cement is more than 20% by mass, and in fly ash, fly ash blended in cement. Means concrete with an amount of more than 20% by mass. The amount of the SCM admixture blended in the cement is synonymous with the substitution rate of the SCM admixture with respect to the cement, and specifically means the content of the SCM admixture in the total amount of the cement and the SCM admixture. do.

The blast furnace slag means a fine powder having a blast furnace slag composition having a brain specific surface area of 3,000 to 10,000 cm ² / g, and the blast furnace slag fine powder specified in JIS A 6206: 2013 is preferable. JIS A 6206: 2013 exemplifies blast furnace slag fine powders 3000, 4000, 6000, and 8000 classified by brain specific surface area, and among these, blast furnace slag fine powder 4000 is exemplified from the viewpoint of supply and cost. More preferred.

Silica fume means a fine powder having a silica fume composition having a BET specific surface area of 15 to 35 m ² / g. The silica fume is a silica fume for concrete specified in JIS A 6207: 2016, and may be in the form of powder, granules, or slurry suspended with water.

The fly ash means a fine powder having a fly ash composition having a specific surface area of 1,500 to 7,000 cm ² / g, and the fly ash for concrete specified in JIS A 6201: 2015 is preferable. JIS A 6201: 2015 exemplifies the types of fly ash I, II, III and IV, and among these, fly ash II is more preferable from the viewpoint of supply and cost.

[Micible]
The admixture according to the present invention is an admixture for concrete containing a high content of SCM admixture, and has at least one structural unit (I), at least one structural unit (II), and at least one structural unit (III). Contains polycondensate with.
The structural unit (I) is an aromatic moiety having a polyether side chain having an alkylene glycol unit, however, the number of ethylene glycol units in the polyether side chain is 9 to 41, and the ethylene glycol unit is the same. The content is more than 80 mol% with respect to all alkylene glycol units in the polyether side chain.
The structural unit (II) is an aromatic moiety having at least one phosphate ester group and / or a salt thereof, where the value of the molar ratio of the structural unit (I) to the structural unit (II) is 0. 3-4,
The structural unit (III) is at least one methylene unit (-CH _2- ), and the methylene unit is bound to two aromatic structural units Y, the structural unit (I) and the structural unit (II). Here, the aromatic structural unit Y is independent of each other and is the same or different, and
The mass average molecular weight Mw of the polycondensate containing the structural units (I), (II) and (III) is in the range of 3,000 to 50,000.
By using such an admixture for concrete containing a large amount of SCM admixture, it is possible to suppress deterioration of fluidity and state with elapsed time. Therefore, it is possible to maintain the workability of concrete and extend the pot life.

<Structural unit (I)>
It has been demonstrated that the structural unit (I) is advantageous to have a minimum polyether side chain length in order to obtain a reasonable dispersive effect in cement binder systems, especially concrete. Very short chains are economically unfavorable. This is because the dispersibility of the admixture is low and the supply amount required to obtain the dispersive action is large. On the other hand, if the polyether side chain of the polycondensate is too long, such admixture is required. The rheological properties of concrete made with the agent deteriorate (high viscosity). The content of ethylene glycol units in the polyether side chain is preferably more than 80 mol% with respect to all alkylene glycol units in the polyether side chain in order to sufficiently make the polycondensate product soluble. It is more preferably more than 85 mol%, further preferably more than 90 mol%, and most preferably more than 95 mol%.

In structural unit (I), the aromatic moiety has one or more polyether side chains, preferably one polyether side chain. Structural units (I) are independent of each other and are the same or different. This means that one or more of the structural units (I) may be present in the polycondensate. The structural unit (I) may differ, for example, in terms of the type of the polyether side chain and the type of aromatic structure.

The structural unit (I) is derived from each aromatic monomer, which is an aromatic monomer having a polyether side chain containing an alkylene glycol unit, the side chain length, and the content of ethylene glycol in the side chain. Meet the above requirements for. When this monomer is incorporated into the polycondensate by the polycondensation reaction, it is incorporated into the polycondensate by the formaldehyde of the monomer and the monomer that becomes the structural unit (I). In particular, the structural unit (I) is an aromatic monomer derived by the absence of two hydrogen atoms (forming water with one oxygen atom from formaldehyde) extracted from the monomer during the polycondensation reaction. Is different.

The aromatic moiety in the structural unit (I) is preferably a substituted or unsubstituted aromatic moiety having a polyether side chain according to the present invention, and the aromatic is a naphthalene ring even if it is a benzene ring. May be. It is possible that one or more polyether side chains, preferably one or two polyether side chains, most preferably one polyether side chain, are present in the structural unit (I). In this context, the "substituted aromatic moiety" preferably means any substituent other than the polyether sidechain or the polyether sidechain according to the invention. The substituent is preferably a C ₁ to C ₁₀ alkyl group, and most preferably a methyl group. The aromatic moiety preferably has 5 to 10 carbon atoms, more preferably 5 to 6 carbon atoms in the aromatic structure, and most preferably the aromatic structural unit has 6 carbon atoms. Benzene or a substituted derivative of benzene. Further, the aromatic portion in the structural unit (I) may be a heterocyclic aromatic structure containing an atom different from carbon, for example, oxygen (in furfuryl alcohol), but an atom having an aromatic ring structure may be used. It is preferably a carbon atom.

The number of ethylene glycol units in the polyether side chain of the structural unit (I) is 9 to 41, preferably 9 to 35, and more preferably 12 to 23. The relatively short polyether side chain length contributes to the good rheological properties of the concrete produced using the admixture according to the present invention containing the polycondensate having the structural unit (I), and particularly low plastic viscosity is obtained. Be done. On the other hand, a chain length on the side chain that is too short is economically undesirable because it reduces the dispersive action and increases the supply required to obtain a certain level of workability (eg, slump in concrete tests).

The structural unit (I) may have a relatively long hydrophilic polyether side chain. This causes steric repulsion between the polycondensates adsorbed on the surface of the cement particles, and as a result, the dispersion action can be improved.

The structural unit (I) can be derived from, but is not limited to, the following monomers. For example, ethoxylated derivatives of aromatic alcohols or amines are preferred, ethoxylated derivatives of phenols, cresols, resorcinols, catechols, hydroquinones, naphthols, furfuryl alcohols or anilines are more preferred, especially ethoxylated phenols. preferable. Resorcinol, catechol and hydroquinone preferably have two polyether side chains. Resorcinol, catechol and hydroquinone can have only one polyether side chain in each case. In each case, less than 20 mol% of alkylene glycol units are contained, which are not ethylene glycol units.

（式（Ｉａ）中、
Ａは、同一であるか、又は異なり、炭素原子を５～１０個有する、置換若しくは非置換の芳香族又は複素環式芳香族化合物によって表され、
Ｂは、同一であるか、又は異なり、Ｎ、ＮＨ、又はＯであり、その際、ＢがＮであれば、ｎは２であり、ＢがＮＨ又はＯであれば、ｎは１であり、
Ｒ¹及びＲ²は、相互に独立して、同一であるか又は異なり、分枝鎖状若しくは直鎖状のＣ₁～Ｃ₁₀アルキル基、Ｃ₅～Ｃ₈シクロアルキル基、アリール基、ヘテロアリール基又はＨであり、ただし、ポリエーテル側鎖におけるエチレングリコール単位（Ｒ¹及びＲ²がＨである）の数は、９～４１であり、エチレングリコール単位の含分は、ポリエーテル側鎖中の全てのアルキレングリコールに対して８０ｍｏｌ％超であり、
ａは、同一であるか、又は異なり、１２～５０の整数であり、かつ
Ｘは、同一であるか、又は異なり、直鎖状若しくは分枝鎖状のＣ₁～Ｃ₁₀アルキル基、Ｃ₅～Ｃ₈シクロアルキル基、アリール基、ヘテロアリール基、又はＨである）によって表される。上記式（Ｉａ）において、基「Ａ」が後述する構造単位（ＩＩＩ）のメチレン単位と結合することより、本発明における混和剤の主成分となる重縮合物が形成される。 The structural unit (I) is preferably the following general formula (Ia):

(In formula (Ia),
A is represented by a substituted or unsubstituted aromatic or heterocyclic aromatic compound which is the same or different and has 5 to 10 carbon atoms.
B is the same or different and is N, NH, or O, where n is 2 if B is N and n is 1 if B is NH or O. ,
R ¹ and R ² are independent of each other and are the same or different, and are branched or linear C ₁ to C ₁₀ alkyl groups, C ₅ to C ₈ cycloalkyl groups, aryl groups, and hetero. It is an aryl group or H, but the number of ethylene glycol units (where R ¹ and R ² are H) in the polyether side chain is 9 to 41, and the content of the ethylene glycol unit is the polyether side chain. More than 80 mol% with respect to all alkylene glycols in
a is the same or different and is an integer of 12 to 50, and X is the same or different, linear or branched C ₁ to C ₁₀ alkyl groups, C ₅ -C ₈ is represented by a cycloalkyl group, an aryl group, a heteroaryl group, or H). In the above formula (Ia), the group "A" is bonded to the methylene unit of the structural unit (III) described later to form a polycondensate which is the main component of the admixture in the present invention.

In formula (Ia), A preferably has 5 to 10 carbon atoms in the aromatic structure, more preferably 5 to 6 carbon atoms, and most preferably 6 carbon atoms in the aromatic structure. It is a benzene or a substituted derivative of benzene that has one.

In formula (Ia), B is preferably O (oxygen).

In formula (Ia), R ¹ and R ² are preferably H, methyl, ethyl, or phenyl, more preferably H, or methyl, and particularly preferably H.

In formula (Ia), a is preferably an integer of 9 to 35.

In formula (Ia), X is preferably H.

The structural unit (I) is preferably derived from an alkoxylated aromatic alcohol monomer having a hydroxy group at the end of the polyether side chain, and is particularly preferably a polycondensate of phenylpolyalkylene glycol. preferable. Phenylpolyalkylene glycol can be obtained relatively easily, is economically promising, and has relatively good reactivity with aromatic compounds.

The structural unit (I) is preferably derived from the phenylpolyalkylene glycol represented by the following general formula (V):
-[C ₆ H ₃ -O- (Z ¹ O) _p -H]-(V)

In formula (V), p is an integer of 9 to 41, preferably an integer of 9 to 35, more preferably an integer of 12 to 23, and Z ¹ is 2 to 5 carbon atoms, preferably 2 to 2. It is an alkylene having 3 carbon atoms, but the content of ethylene glycol units (Z ¹ = ethylene) is 80 mol% with respect to all alkylene glycol units in _n of the polyether side chain (Z ¹ O). Ultra, preferably greater than 85 mol%, more preferably greater than 90 mol%, most preferably greater than 95 mol%. In the above formula (V), the aromatic structural portion of "C ₆ H ₃ " is bonded to the methylene unit of the structural unit (III) described later.

The substitution pattern in the aromatic benzene unit (C ₆ H ₃ in the above formula (V)) is the position (1st position) of the oxygen atom bonded to the benzene ring due to the active action (electron donating action) of the oxygen atom bonded to the benzene ring. ), Mainly the ortho substitution position (2nd position) and the para substitution position (4th position).

<Structural unit (II)>
Structural unit (II) results in an anionic group in the polycondensate (from a phosphate ester to its acid or salt form), which is a positive charge present on the surface of the cement particles in the aqueous cement dispersion. It interferes with and is strongly alkaline. Due to the electrostatic attraction, the polycondensate is adsorbed on the surface of the cement particles and the cement particles are dispersed. Here, the term "phosphate ester" preferably refers to phosphate monoesters (PO (OH) ₂ (OR) ₁ ), phosphate diesters (PO (OH) (OR) ₂ ), and / or phosphorus. A mixture of acid triesters (PO (OR) ₃ ) is included. The group R in the phosphoric acid ester defines each alcohol having no OH group after the ester reaction, and this reacts to become an ester with phosphoric acid. The group R preferably has an aromatic moiety. Monoesters are usually the main product of phosphorylation reactions.

The term "phosphorylated monomer" refers to the reaction product of aromatic alcohol with phosphoric acid, polyphosphoric acid or phosphoric acid, and the reaction of aromatic alcohol with a mixture of phosphoric acid, polyphosphoric acid and phosphoric acid. Contains products.

The content of the phosphoric acid monoester is preferably more than 50% by mass based on the total of all the phosphoric acid esters. The content of the structural unit (II) derived from the phosphoric acid monoester is preferably more than 50% by weight based on the total of all the structural units (II).

In structural unit (II), the aromatic moiety preferably contains one phosphate ester group and / or a salt thereof. This means that the use of aromatic monoalcohols is preferred. Further, the structural unit (II) can have more than one phosphoric acid ester group and / or a salt thereof, and preferably has two. In this case, at least one aromatic dialcohol or aromatic polyalcohol is used. Structural units (II) are independent of each other and are the same or different. This means that one or more of the structural units (II) can be present in the polycondensate.

The structural unit (II) in the polycondensate is an aromatic moiety having at least one phosphate ester group and / or a salt thereof, but the value of the molar ratio of the structural unit (I) to the structural unit (II). Is 0.3 to 4, preferably 0.4 to 3.5, more preferably 0.45 to 3, and most preferably 0.45 to 2.5. This range of molar ratios provides sufficient initial dispersibility of the polycondensate (relatively high content of structural unit (II)) and sufficient slump retention properties (relatively high content of structural unit (I)). It is advantageous because it can be achieved in concrete samples.

As described above for structural unit (I), structural unit (II) is also an aromatic monomer derived by the absence of two hydrogen atoms extracted from the monomer during the polycondensation reaction. different.

The aromatic moiety in structural unit (II) is preferably a substituted or unsubstituted aromatic moiety having at least one phosphate ester group and / or a salt thereof, and the aromatic is naphthalene even if it is a benzene ring. It may be a ring. The presence of one or more phosphate ester groups and / or salts thereof in the structural unit (II), preferably the presence of one or two phosphate ester groups and / or salts thereof, most preferably. There may be one phosphate ester group and / or a salt thereof. The aromatic portion of the structural unit (II) preferably has 5 to 10 carbon atoms, more preferably 5 to 6 carbon atoms in the aromatic structure, and most preferably the aromatic structural unit. It is benzene or a substituted derivative of benzene having 6 carbon atoms. Further, the aromatic portion in the structural unit (II) may be a heteroaromatic structure containing an atom different from carbon, for example, oxygen (in furfuryl alcohol), but the atom in the aromatic ring structure is a carbon atom. Is preferable.

The structural unit (II) is preferably derived from an aromatic alcohol monomer. The aromatic alcohol monomer was alkoxylated in the first step, and the obtained alkoxylated aromatic alcohol monomer having a hydroxy group at the end of the polyether side chain was phosphorylated in the second step. Form a phosphate ester group.

The structural unit (II) derived from each phosphorylated aromatic alcohol monomer is different from that described above due to the extraction of two hydrogen atoms from each monomer. Such structural unit (II) is derived from, for example, the following compounds, but is not limited thereto. For example, aromatic alcohol phosphorylation products or hydroquinone phosphorylation products are preferred, such as phenoxyethanol phosphate (aromatic alcohol: phenoxyethanol), phenoxydiglycol phosphate (aromatic alcohol: phenoxydiglycol), (methoxyphenoxy) ethanol phosphate. (Aromatic alcohol: (methoxyphenoxy) ethanol), Methylphenoxyethanol phosphate (Aromatic alcohol: Methylphenoxyethanol), Nonylphenol phosphate (Aromatic alcohol; Nonylphenol), Bis (β-hydroxyethyl) Hydroquinone ether phosphate (Hydroquinone: Bis (β) -Hydroxyethyl) hydroquinone ether), bis (β-hydroxyethyl) hydroquinone ether diphosphate (hydroquinone: bis (β-hydroxyethyl) hydroquinone ether) is more preferred, phenoxyethanol phosphate, phenoxydiglycolphosphate, bis (β-hydroxyethyl). ) Hydroquinone ether diphosphate is particularly preferred, and phenoxyethanol phosphate is most preferred. A mixture of the above monomers from which the structural unit (II) is derived may be used.

During the phosphorylation reaction (eg, the reaction of the aromatic alcohol containing hydroquinone with phosphoric acid), the main product (monoester of phosphoric acid and one equivalent of aromatic alcohol: (PO (OH)) is usually used. It should be noted that in addition to ₂ (OR) ₁ )), by-products are also formed. The by-product is, in particular, a diester of phosphoric acid and 2 equivalents of aromatic alcohol (PO (OH) (OR) ₂ ), or a triester of phosphoric acid and 3 equivalents of aromatic alcohol (PO (OR)). ₃ ). The formation of the triester requires a temperature above 150 ° C. and is therefore not normally produced. Here, the group R in the phosphoric acid ester is an aromatic alcohol structure having no OH group after the ester reaction. Unreacted alcohol may be present to some extent in the reaction mixture. Its content is usually less than 35% by weight, preferably less than 5% by weight, of the aromatic alcohol used. The main product (monoester) after the phosphorylation reaction is usually present in the reaction mixture at a level of more than 50% by mass, preferably more than 65% by mass, based on the aromatic alcohol used.

（式（ＩＩａ）中、
Ｄは、同一であるか、又は異なり、炭素原子を５～１０個有する、置換若しくは非置換の芳香族又は複素環式芳香族化合物によって表され、
Ｅは、同一であるか、又は異なり、Ｎ、ＮＨ、又はＯであり、ＥがＮであれば、ｍは２であり、ＥがＮＨ又はＯであれば、ｍは１であり、
Ｒ³及びＲ⁴は、相互に独立して、同一であるか、又は異なり、直鎖状若しくは分枝鎖状のＣ₁～Ｃ₁₀アルキル基、Ｃ₅～Ｃ₈シクロアルキル基、アリール基、ヘテロアリール基又はＨであり、
ｂは、同一であるか、又は異なり、０～１０の整数であり、かつ
Ｍａは、相互に独立して、同一であるか、又は異なり、Ｈ又はカチオン等価物である）で表される。上記式（ＩＩａ）において、基「Ｄ」が後述する構造単位（ＩＩＩ）のメチレン単位と結合することより、本発明における混和剤の主成分となる重縮合物が形成される。 The structural unit (II) is preferably the following general formula (IIa):

(In formula (IIa),
D is represented by a substituted or unsubstituted aromatic or heterocyclic aromatic compound which is the same or different and has 5 to 10 carbon atoms.
E is the same or different, N, NH, or O, if E is N, m is 2, and if E is NH or O, m is 1.
R ³ and R ⁴ are mutually independent, identical or different, linear or branched C ₁ to C ₁₀ alkyl groups, C ₅ to C ₈ cycloalkyl groups, aryl groups, Heteroaryl group or H,
b is the same or different and is an integer from 0 to 10, and Ma is independent of each other and is the same or different and is H or a cation equivalent). In the above formula (IIa), the group "D" is bonded to the methylene unit of the structural unit (III) described later to form a polycondensate which is the main component of the admixture in the present invention.

In formula (IIa), D preferably has 5 to 10 carbon atoms in the aromatic structure, more preferably 5 to 6 carbon atoms in the aromatic structure, and most preferably in the aromatic structure. It is benzene or a substituted derivative of benzene having 6 carbon atoms.

In formula (IIa), E is preferably O (oxygen).

In formula (IIa), R ³ and R ⁴ are mutually independent, preferably H, methyl, ethyl, or phenyl, more preferably H or methyl, particularly preferably H, and most preferably. R ³ and R ⁴ are both H.

In formula (IIa), b is preferably an integer of 1 to 5, more preferably an integer of 1 to 2, and most preferably 1.

The phosphoric acid ester represented by the formula (IIa) can be an acid having two acidic protons (Ma = H). Phosphate esters can also be present in deprotonated form, in which case the protons are replaced by cation equivalents. The phosphate ester may be partially deprotonated. The term "cation equivalent" means any metal cation, or optionally substituted ammonium cation (which can replace the proton), but the molecule is electrically neutral. Ma is preferably NH ₄ , alkali metal or metalloid earth metal.

The group A of the structural unit (Ia) and the group D of the structural unit (IIa) are, for example, phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2-methoxyphenyl independently of each other. , 3-methoxyphenyl, 4-methoxyphenyl is preferable, and phenyl is more preferable. A plurality of structural units (Ia) having different types of groups A may be present in the polycondensate, and a plurality of structural units (IIa) having different types of groups D may also be present in the polycondensate. good. The group B and the group E are preferably O (oxygen) independently of each other.

The structural unit (II) is preferably an alkoxylated phenolic phosphate ester, as represented by the following general formula (VI), or an alkoxylation as represented by the following general formula (VII). Derived from the hydroquinone phosphate that has been added:
-[C ₆ H ₃ -O- (Z ² O) _q -PO ₃ M ₂ ]-(VI)
-[[M ₂ O ₃ P- (Z ³ O) _r ] -OC ₆ H ₂ -O- [(Z ⁴ O) _s -PO ₃ M ₂ ]]-(VII)

In any of the formulas (VI) and (VII), q, r, s are integers of 1 to 5, preferably integers of 1 to 2, more preferably 1, and Z ² , Z ³ and Z ⁴ are. It is an alkylene having 2 to 5 carbon atoms, preferably 2 to 3 carbon atoms independently of each other, and more preferably ethylene. M is independent of each other and is the same or different, H, or a cation equivalent. In the above formula (VI), the aromatic structural portion of "C ₆ H ₃ " and in the above formula (VII), the aromatic structural portion of "C ₆ H ₂ " are methylene of the structural unit (III) described later. Combined into units.

The esters of the general formulas (VI) and (VII) may be acids with two acidic protons (M = H). This ester can also be present in deprotonated form, in which case the protons are replaced by cation equivalents. This ester may be partially deprotonated. The term cation equivalent is as described above, where M is preferably NH ₄ , alkali metal, or metalloid alkaline earth metal. So, for example, in the case of two positively charged alkaline earth metals, a coefficient of 1/2 must exist (1/2 alkali metal) to guarantee neutrality, eg, metal. When the component "M" is Al ³⁺ , 1/3 Al is a cation equivalent. Further, for example, it may be a mixed cation equivalent having two or more kinds of metal cations.

Such an alkoxylated phenol phosphate ester or an alkoxylated hydroquinone phosphate ester is economically desirable because it can be obtained relatively easily, and the reactivity of the aromatic compound in the polycondensation reaction is also high. It is relatively good.

<Structural unit (III)>
The structural unit (III) is at least one methylene unit (-CH _2- ), and the methylene unit is bound to two aromatic structural units, the structural unit (I) and the structural unit (II). , The aromatic structural units are independent of each other and are the same or different and correspond to the above aromatic portions in the structural unit (I) and the structural unit (II). The methylene unit is introduced by the reaction of formaldehyde while forming water during the polycondensation, preferably more than one methylene unit is contained in the polycondensate.

<Structural unit (IV)>
The polycondensate may further have at least one structural unit (IV). The structural unit (IV) is an aromatic structural unit of the polycondensate, which is different from the structural unit (I) and the structural unit (II), and can be any aromatic structural unit. When the structural unit (IV) is included, the methylene unit in the structural unit (III) is combined with three aromatic structural units of the structural unit (I), the structural unit (II) and the structural unit (IV). The aromatic structural units in the structural unit (IV) are independent of each other and are the same or different. This means that one or more of the structural units (IV) can be present in the polycondensate.

The structural unit (IV) can be derived, for example, from any aromatic monomer capable of reacting with formaldehyde in a polycondensation reaction, with two hydrogen atoms extracted from each monomer. Examples of the monomer for inducing the structural unit (IV) include phenoxyalcohol, phenol, naphthol, aniline, benzene-1,2-diol, benzene-1,2,3-triol, 2-hydroxybenzoic acid, 2,3-. Examples thereof include dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,4,5-trihydroxybenzoic acid, phthalic acid, 3-hydroxyphthalic acid, 1,2-dihydroxynaphthalene, and 2,3-dihydroxynaphthalene. , Not limited to these.

Further, the structural unit (IV) may be a structural unit similar to the structural unit (I) in which only the number of ethylene glycol units in the side chain is different. The structural unit (IV) is preferably an aromatic moiety having a polyether side chain having an alkylene glycol unit, except that the number of ethylene glycol units in the polyether side chain is 42 to 120. Moreover, the content of the ethylene glycol unit is more than 80 mol% with respect to all the alkylene glycol units in the polyether side chain, which is a structural unit.

<Polycondensate>
The polycondensate contained in the admixture according to the present invention is the main component of the admixture and contains the structural units (I), (II) and (III), and the structural unit (I). , (II), (III), and (IV) are contained, and the mass average molecular weight Mw of the polycondensate is in the range of 3,000 to 50,000.

In the polycondensate, the molar ratio of the ethylene glycol unit from the structural unit (I) to the phosphate ester unit from the structural unit (II) is preferably 11 to 40/1, more preferably 12 to 35/1. , 13 to 30/1 is more preferable. In order to specify the ratio of this molar ratio, the existence of different kinds of structural units (I) is also taken into consideration, and the total of all ethylene glycol units from the structural unit (I) is calculated.

When calculating the value of the molar ratio of the ethylene glycol unit from the structural unit (I) to the phosphate ester unit from the structural unit (II), the minimum of 9 and the maximum of 41 in the structural unit (I) are calculated. The alkylene glycol is combined with the value of the molar ratio of the structural unit (I) to 0.3-4 to the structural unit (II), and the minimum value is 9/8 (structural unit (I) / structural unit (II). ) Has a short side chain of 9EO with a molar ratio value of 4, as well as the possibility that two phosphate ester groups may be present in the structural unit (II)). On the other hand, in combination with the lower limit of the molar ratio of structural unit (I) / structural unit (II) of 0.3, the long side chains of 41 EOs and the phosphate ester present in structural unit (II). Considering the above, a maximum value of 136.7 (41 / 0.3) is obtained. When the molar ratio of the ethylene glycol unit from the structural unit (I) to the phosphoric acid ester unit from the structural unit (II) is lower than the lower limit (9/8), the phosphoric acid ester group is surplus, so that the concrete test piece The slump retention in is worse. On the other hand, when this molar ratio is larger than the upper limit value (136.7), the adsorptivity to cement particles is too weak, so that the water reduction characteristics (initial water reduction rate in the concrete test piece) are not very good. As described above, the range of the molar ratio of the ethylene glycol unit from the structural unit (I) to the phosphoric acid ester unit from the structural unit (II) is in the range of 9/8 to 136.7, so that the concrete test piece In, an appropriate balance between the two characteristics of slump retention and water reduction rate can be obtained, and both good water reduction rate and good slump retention can be obtained. In addition, the viscosity of concrete can be lowered.

The total molar ratio of structural units (I) and (II) to structural unit (III) is preferably 0.8 / 1 to 1 / 0.8, more preferably 0.9 / 1 to 1 / 0.9. , Most preferably 1/1.

When the structural unit (IV) is further contained in the polycondensate, the total molar ratio of the structural unit (I) and the structural unit (II) to the structural unit (IV) is preferably more than 1/1. It is more preferably more than 3/1, still more preferably more than 5/1.

The structural unit (IV) is most preferably a polycondensate which is an aromatic moiety having a polyether side chain containing an alkylene glycol unit, provided that the number of ethylene glycol units in the polyether side chain of the structural unit (IV). Is 42 to 50, and the content of ethylene glycol units is more than 80 mol% with respect to all alkylene glycol units in the polyether side chain of the structural unit (IV).

The mass average molecular weight Mw of the polycondensate is 3,000 to 50,000 g / mol, preferably 5,000 g / mol to 25,000 g / mol, and more preferably 8,000 g / mol to 22, It is 000 g / mol, most preferably 10,000 g / mol to 19,000 g / mol.

The mass average molecular weight Mw of the polycondensate is the mass average molecular weight of the polycondensate specified by GPC. The column combination is OH-Pak SB-G, OH-Pak SB 804 HQ, and OH-Pak SB 802.5 HQ (manufactured by Shodex, Japan), and the eluent is 80% by volume HCO ₂ NH ₄ aqueous solution. (0.05 mol / l) and 20% by volume acetonitrile, and the injection volume; 100 μl, flow rate; 0.5 ml / min. Molecular weight calibration is performed using the poly (styrene sulfonate) standard for UV detectors and the poly (ethylene oxide) standard for RI detectors. Both standards can be purchased from the PSS Polymer Standards Service in Germany. UV detection is used at 254 nm to determine the molecular weight of the polymer. Since the UV detector does not detect inorganic impurities, it can only detect aromatic compounds.

<Retention aid>
The admixture according to the present invention may further contain a retention aid as a retention component in addition to the above polycondensate. The additional retention aid suppresses the aging of the concrete and allows for better control of the workability of the concrete over a longer period of time. As a result, it is possible to further suppress the decrease in fluidity and state with the elapsed time. The content of such a retention aid is preferably 5 to 50% by mass with respect to the total mass of the polycondensate in the admixture.

As one of such retention aids, for example, a copolymer obtained by polymerizing a hydrolyzable monomer, an ethylenically unsaturated monomer containing a polyoxyalkylene group, and a cement-adsorbing monomer (coweight). It is preferable to use the union 1).

(Hydrolytic monomer)
The hydrolyzable monomer is preferably an ethylenically unsaturated monomer capable of forming a hydrolyzable monomer residue. Examples of such hydrolyzable monomers include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate;
Hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate;
(Meta) acrylamide and its derivatives; and maleic acid (mono) alkyl esters, maleic anhydride, maleimide; and the like, but are not limited thereto. These may be used alone or in combination of two or more.

(Ethylene unsaturated monomer containing polyoxyalkylene group)
Examples of the ethylenically unsaturated monomer containing a polyoxyalkylene group include saturated monocarboxylic acid ester derivatives such as polyethylene glycol mono (meth) acrylate, polypropylene glycol (meth) acrylate, polybutylene glycol (meth) acrylate, and polyethylene glycol polypropylene glycol. Mono (meth) acrylate, polyethylene glycol polybutylene glycol mono (meth) acrylate, polypropylene glycol polybutylene glycol mono (meth) acrylate, polyethylene glycol polypropylene glycol polybutylene glycol mono (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate, Methoxypolyethylene glycol mono (meth) acrylate, methoxypolybutylene glycol mono (meth) acrylate, methoxypolyethylene glycol polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol polybutylene glycol mono (meth) acrylate, methoxypolyethylene glycol polybutylene glycol mono ( Meta) acrylate, methoxypolyethylene glycol polypropylene glycol polybutylene glycol mono (meth) acrylate, ethoxypolyethylene glycol mono (meth) acrylate, ethoxypolyethylene glycol mono (meth) acrylate, ethoxypolybutylene glycol mono (meth) acrylate, ethoxypolyethylene glycol polypropylene Glycol mono (meth) acrylate, ethoxypolyethylene glycol polybutylene glycol mono (meth) acrylate, ethoxypolyethylene glycol polybutylene glycol mono (meth) acrylate, ethoxypolyethylene glycol polypropylene glycol polybutylene glycol mono (meth) acrylate, and the above polyoxyalkylene. Higher alkoxy derivative of
Vinyl alcohol derivatives such as polyethylene glycol mono (meth) vinyl ether, polypropylene glycol mono (meth) vinyl ether, polybutylene glycol mono (meth) vinyl ether, polyethylene glycol polypropylene glycol mono (meth) vinyl ether, polyethylene glycol polybutylene glycol mono (meth). Vinyl Ether, Polyethylene Glycol Polybutylene Glycol Mono (Meta) Vinyl Ether, Polyethylene Glycol Polyethylene Glycol Polybutylene Glycol Mono (Meta) Vinyl Ether, methoxy Polyethylene Glycol Mono (Meta) Vinyl Ether, methoxy Polyethylene Glycol Mono (Meta) Vinyl Ether, methoxy Polybutylene Glycol Mono ( Meta) Vinyl Ether, Polyethylene Glycol Polyethylene Glycol Glycol Mono (Meta) Vinyl Ether, Polyethylene Glycol Polybutylene Glycol Mono (Meta) Vinyl Ether, Polyethylene Glycol Polybutylene Glycol Mono (Meta) Vinyl Ether, Polyethylene Glycol Polyethylene Glycol Polybutylene Glycol Mono (Meta) ) Vinyl ether, ethoxypolyethylene glycol mono (meth) vinyl ether, ethoxypolyethylene glycol mono (meth) vinyl ether, ethoxypolybutylene glycol mono (meth) vinyl ether, ethoxypolyethylene glycol polypropylene glycol mono (meth) vinyl ether, ethoxypolyethylene glycol polybutylene glycol mono ( Meta) vinyl ether, ethoxypolyethylene glycol polybutylene glycol mono (meth) vinyl ether and ethoxypolyethylene glycol polypropylene glycol polybutylene glycol mono (meth) vinyl ether, etc .;
(Meta) allyl alcohol derivatives such as polyethylene glycol mono (meth) allyl ether, polypropylene glycol mono (meth) allyl ether, polybutylene glycol mono (meth) allyl ether, polyethylene glycol polypropylene glycol mono (meth) allyl ether, polyethylene glycol. Polybutylene glycol mono (meth) allyl ether, polypropylene glycol polybutylene glycol mono (meth) allyl ether, polyethylene glycol polypropylene glycol polybutylene glycol mono (meth) allyl ether, methoxypolyethylene glycol mono (meth) allyl ether, methoxypolypropylene glycol mono (Meta) allyl ether, methoxypolybutylene glycol mono (meth) allyl ether, methoxypolyethylene glycol polypropylene glycol mono (meth) allyl ether, methoxypolyethylene glycol polybutylene glycol mono (meth) allyl ether, methoxypolypropylene glycol polybutylene glycol mono (meth) Meta) allyl ether, methoxypolyethylene glycol polypropylene glycol polybutylene glycol mono (meth) allyl ether, ethoxypolyethylene glycol mono (meth) allyl ether, ethoxypolypropylene glycol mono (meth) allyl ether, ethoxypolybutylene glycol mono (meth) allyl ether , Ethoxypolyethylene glycol polypropylene glycol mono (meth) allyl ether, ethoxypolyethylene glycol polybutylene glycol mono (meth) allyl ether, ethoxypolypropylene glycol polybutylene glycol mono (meth) allyl ether and ethoxypolyethylene glycol polypropylene glycol polybutylene glycol mono (meth) ) Allyl ether, etc .;
Additions of alkylene oxide and unsaturated alcohol, such as polyethylene glycol mono (3-methyl-3-butenyl) ether, polyethylene glycol mono (3-methyl-2-butenyl) ether, polyethylene glycol mono (2-methyl-3-3). Butenyl) ether, polyethylene glycol mono (2-methyl-2-butenyl) ether, polyethylene glycol mono (1,1-dimethyl-2-propenyl) ether, polyethylene glycol glycol mono (3-methyl-3-butenyl) ether, polypropylene Glycol mono (3-methyl-3-butenyl) ether, methoxypolyethylene glycol mono (3-methyl-3-butenyl) ether, ethoxypolyethylene glycol mono (3-methyl-3-butenyl) ether, 1-propoxypolyethylene glycol mono ( 3-Methyl-3-butenyl) ether, cyclohexyloxypolyethylene glycol mono (3-methyl-3-butenyl) ether, 1-octyloxypolyethylene glycol mono (3-methyl-3-butenyl) ether, nonylalkoxypolyethylene glycol mono (3-methyl-3-butenyl) ether 3-Methyl-3-butenyl) ether, laurylalkoxypolyethylene glycol mono (3-methyl-3-butenyl) ether, stearylalkoxypolyethylene glycol mono (3-methyl-3-butenyl) ether and phenoxypolyethylene glycol mono (3-methyl) -3-Butenyl) ether; etc., but not limited to these. Additives of alkylene oxides and unsaturated alcohols include, for example, 1-35 mol of additives of alkylene oxides and unsaturated alcohols, such as 3-methyl-3-butene-1-ol, 3-methyl-2-butene-. Additions with unsaturated alcohols such as 1-ol, 2-methyl-3-butene-2-ol, 2-methyl-2-buten-1-ol and 2-methyl-3-buten-1-ol. However, it is not limited to these. The above-mentioned ethylenically unsaturated monomer containing a polyoxyalkylene group may be used alone or in combination of two or more.

The ethylenically unsaturated monomer containing such a polyoxyalkylene group can contain an oxyalkylene group having a plurality of side chain lengths. For example, it contains at least one ethylenically unsaturated carboxylic acid ester or alkenyl ether monomer containing at least one C _2-4 oxyalkylene group in 1 to 30 units and at least one C ₂ in 31 to 350 units. _-4 It may contain at least one ethylenically unsaturated carboxylic acid ester or alkenyl ether monomer containing an oxyalkylene group.

(Cement adsorptive monomer)
The cement-adsorbable monomer is preferably an ethylenically unsaturated monomer having a carboxyl group, a sulfone group or a phosphon group at the terminal. As the ethylenically unsaturated monomer having a carboxy group, unsaturated carboxylic acid-based monomers such as (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid and fumaric acid or salts thereof are preferable, for example, alkali metal salts and alkaline soils. Examples thereof include metal salts, ammonium salts, amine salts and the like. More preferably, it is (meth) acrylic acid or an alkali metal salt thereof, and more preferably acrylic acid or a sodium salt thereof. Examples of the ethylenically unsaturated monomer having a sulfonic acid group include (meth) allyl sulfonic acid or a salt thereof, for example, an alkali metal salt, an alkaline earth metal salt, an ammonium salt, an amine salt and the like, and (meth) allyl is preferable. It is a sodium salt of sulfonic acid, more preferably a sodium salt of metallicyl sulfonic acid. As the ethylenically unsaturated monomer having a phosphone group, phosphoric acid mono (2-hydroxyethyl) (meth) acrylic ester, phosphoric acid di- (2-hydroxyethyl) (meth) acrylic ester and the like are preferable. These may be used alone or in combination of two or more.

In the copolymer 1, the molar ratio of the hydrolyzable monomer (A), the ethylenically unsaturated monomer (B) containing a polyoxyalkylene group, and the cement-adsorbable monomer (C), that is, (A) :( B). ): (C) is preferably 0.5: 1: 0.3 to 10: 1:10, and more preferably 0.5: 1: 0.3 to 5: 1: 5.

As another retention aid, for example, a copolymer formed by polymerizing the above-mentioned hydrolyzable monomer and the above-mentioned ethylenically unsaturated monomer containing a polyoxyalkylene group without containing the above-mentioned cement-adsorbing monomer. It is preferable to use a coalescence (copolymer 2). That is, the copolymer 2 does not have the structural unit derived from the above-mentioned cement-adsorbable monomer, but contains the above-mentioned structural unit derived from the hydrolyzable monomer and the above-mentioned polyoxyalkylene group. It is a copolymer containing a structural unit derived from an ethylenically unsaturated monomer.

In the copolymer 2, the molar ratio of the hydrolyzable monomer (A) to the ethylenically unsaturated monomer (B) containing a polyoxyalkylene group, that is, (A): (B) is preferably 1: 1 to 1. It is 10: 1, more preferably 1: 1 to 9: 1.

<Delayant>
The admixture according to the present invention has oxycarboxylic acid and oxycarboxylate as delay components having a delay effect in order to adjust the coagulation properties of the obtained cement composition and the flow retention of the slump flow, if necessary. , A retarder selected from the group consisting of sugars and sugar alcohols may be included. The oxycarboxylic acid is preferably citric acid, gluconic acid, fumaric acid or the like, and the salt thereof is preferably an alkali metal salt. The saccharides are preferably maltose, lactose, xylose, saccharose and the like, and the sugar alcohols are preferably sorbitol, xylitol, erythritol and the like. The retarder may be contained as a part of the component of the admixture of one embodiment, or may be added to concrete separately from the admixture of one embodiment. When it is used as a part of the component of the admixture of one embodiment, it is preferably contained in an amount of 1 to 10% by mass with respect to the admixture of one embodiment, as long as the effect of the present invention is not impaired.

[Miscible-containing composition]
The admixture-containing composition according to the present invention contains the above-mentioned admixture and a curing accelerator. That is, the admixture-containing composition is not intended only in a one-component state in which the curing accelerator is contained as a part of the above-mentioned admixture component, and the curing accelerator is the above-mentioned admixture. May be in the state of a two-component type (attached type) added separately. Such a curing accelerator is preferably a curing accelerator in which CSH nanoparticles are dispersed as CSH fine particles. The curing accelerator in which CSH-based nanoparticles are dispersed is preferable because the main component is the same as that of cement hydrate. The dispersant for dispersing the CSH nanoparticles is not particularly limited, but is at least selected from, for example, polyalkylene glycol having a functional group at the terminal, a water-soluble comb polymer and a polyaryl ether compound. It is preferably one kind.

The calcium silicate hydrate constituting the CSH nanoparticles is described in the following general formula (VIII).
dCaO ・ SiO ₂・ eH ₂ O ... (VIII)
(In formula (VIII),
d is preferably 0.1 ≦ d ≦ 2, more preferably 0.66 ≦ d ≦ 1.8, and is
e is preferably represented by 0.6 ≦ e ≦ 6, more preferably 1.2 ≦ e ≦ 5.5).

The particle size of the calcium silicate hydrate is preferably less than 1000 nm, more preferably less than 300 nm, still more preferably less than 200 nm. The particle size of calcium silicate hydrate can be measured by an analytical ultracentrifugation method.

Examples of calcium silicate hydrate include fossag stone, fin brand stone, zonotrite, cat stone, monoclinic tobermori stone, 9Å-tobamolite (riverside stone), 11Å-tobamolite, 14Å-tobamolite (prombiel stone), and genni stone. , Metagennite, calcium chondrodite, affiliite, α-C ₂ SH, dellite, jafe stone, Rosenhan stone, Kirara stone, Sorn stone. In particular, zonotrite, 9Å-tobamolite (riverside stone), 11Å-tobamolite, 14Å-tobamolite (prombiel stone), genni stone, metagennite, affiliite and jafe stone are preferable.

The curing accelerator may further contain a thickener polymer. The thickener polymer is selected from the group of polysaccharide derivatives and (co) polymers having a mass average molecular weight Mw of more than 500,000 g / mol, preferably more than 1,000,000 g / mol.

Such a curing accelerator may be used alone or in combination of two or more. The content of the curing accelerator is not particularly limited, and can be appropriately set according to the usage situation.

Other additives can be added to the admixture according to the present invention as needed. Other additives include conventionally used AE agents, polysaccharide derivatives, lignin derivatives, dry shrinkage reducing agents, accelerators, foaming agents, defoaming agents, rust preventives, quick-setting agents, and highly water-soluble agents. Examples include molecular substances. Other additives may be contained as a part of the components of the admixture according to the present invention, or may be added to concrete separately from the admixture according to the present invention. When it is used as a part of the component of the admixture according to the present invention, it is preferably contained in an amount of 1 to 20% by mass with respect to the admixture according to the present invention, as long as the effect of the present invention is not impaired.

<Cement composition>
The cement composition according to the present invention contains the above-mentioned admixture, and commercially available cement can be used as the cement. Among such cements, it is preferable to use ordinary Portland cement and / or moderate heat or low heat cement from the viewpoint of versatility. In the present invention, ordinary Portland cement is particularly preferable from the viewpoint of good durability of the obtained cement composition and cost due to a small amount of cement additive added.

(Other powders)
Fine powder admixtures such as limestone powder, calcium carbonate, and swelling material can be added as a powder having no latent hydraulic or pozzolan activity, which is a partial substitute for or is added to the cement contained in the cement composition. .. These powders have a blending amount of 0 to 0 to 1 m ³ of the cement composition in order to suppress material separation, maintain appropriate viscosity and high fluidity, and do not interfere with the effects of the present invention. It is preferably 100 kg / m ³ .

(aggregate)
In the cement composition according to the present invention, it is preferable to use natural aggregate. It is preferable to use sea sand, land sand, mountain sand, crushed sand or the like as the fine aggregate, and it is preferable to use mountain gravel, river gravel, sea gravel, crushed stone or the like as the coarse aggregate. Concrete using these aggregates can easily obtain the effect of this additive. In addition, the particle size of the aggregate is preferably an aggregate having an appropriate particle size distribution from the viewpoint of ensuring fluidity, and the particle size distribution of the aggregate specified in JIS A 5308 Annex A Ready-mixed concrete aggregate is used. It is preferable to have it.

<Concrete type>
The admixture according to the present invention can be applied to a cement composition containing a large amount of SCM admixture. Specifically, for example, when the blast furnace slag is contained as the SCM admixture, it is applied to the SCM admixture high content concrete in which the replacement rate of the blast furnace slag with respect to cement is more than 60%. Further, for example, when silica fume is contained as the SCM admixture, it is applied to concrete containing a high amount of silica fume with respect to cement, and when fly ash is contained as the SCM admixture, cement is applied. It is applied to concrete containing high SCM admixture with a replacement rate of fly ash of more than 20%. If the substitution rate of the SCM admixture is lower than the above ratio, the effect of the admixture according to the present invention may not be different from that of the prior art.

Further, the cement composition containing the admixture according to the present invention can be preferably used as mass concrete such as dams, watertight concrete such as hydraulic facilities, and marine concrete such as marine piers and submerged boxes, and these uses. Is preferable because the excellent effect of mixing the SCM admixture can be obtained and the fluidity and state of the concrete containing a high amount of the SCM admixture can be maintained.

<Manufacturing of concrete>
The cement composition according to the present invention can be produced by a conventionally known method, for example, in accordance with the concrete standard specifications established by the Japan Society of Civil Engineers and the building construction standard specifications prepared by the Architectural Institute of Japan. It can be produced by a known facility and a known method. Specifically, a method of adding the admixture according to the present invention to the kneaded water in advance and then adding other raw materials such as cement and aggregate to the mixer to produce the mixture, and all the raw materials contained in the cement composition. A method of collectively manufacturing by putting into a mixer is preferable. Further, the cement composition according to the present invention is preferably produced in a ready-mixed concrete plant according to JIS A 5308.

Hereinafter, the admixture according to the present invention and the cement composition using the admixture will be described in detail with reference to examples. The present invention is not limited to the examples shown below.

Using the materials used in Table 1, concrete was produced from the cement composition under the compounding conditions shown in Table 2. The slump and slump flow of the obtained concrete were measured, and the state of the slump was visually observed.

<Material used>

<Cement composition formulation>

<Mixing method>
Of the above materials, cement (C), SCM admixture (SG) and aggregate (S, G) were put into a biaxial forced kneading mixer SD-55 manufactured by Pacific Kiko Co., Ltd. and kneaded for 60 seconds. After stopping the mixing once, add water (W) and a solution in which the admixtures (SP1, SP2), retarder (RT) and retention aid (RA) are mixed in advance, and knead for another 60 seconds to knead the concrete. Obtained. The addition amounts of the admixtures (SP1, SP2), the retarder (RT) and the retention aid (RA) were adjusted according to the blending amounts shown in Table 3 and adjusted to the target slump values.

<Measurement / evaluation>
The slump value and slump flow value immediately after kneading (0 minutes) and 60 minutes later were measured, and the state of the slump was visually observed. Each item was evaluated as follows.

<Slump>
The slump value was measured based on JIS A 1101. According to the amount of decrease in slump 60 minutes after kneading, it was classified into the following three categories and evaluated as fluidity with elapsed time.
"◎" Excellent: Less than 5 cm "○" Good: 5 cm or more and less than 10 cm "×" Defective: 10 cm or more

<Slump flow>
The slump flow value was measured based on JIS A 1150.

<Slump state>
The deformation behavior of the slump in the slump test was visually classified into the following three categories by the measurer and evaluated as a state.
"◎" Excellent: "○" deformed as a unit Good: Slump collapsed slightly, but deformed as a whole "x" Separation: Slump collapsed and deformed

The test results are shown in Table 3.

Comparing the concrete to which SP1 is added (hereinafter referred to as "SP1 con") and the concrete to which SP2 is added (hereinafter referred to as "SP2 con"), the slag replacement rate is 0 as in Reference Example 1 and Reference Example 2. When SP1 concrete and SP2 concrete were prepared from the cement composition of "SG-0", the amount of decrease in slag after 60 minutes was within 5 cm in each case. Therefore, both were excellent in fluidity with the elapsed time, and no separation of the slump state was observed. Further, when SP1 and SP2 are respectively prepared from the cement composition of "SG-50" having a slag replacement rate of 50% as in Reference Example 3 and Reference Example 4, SP2 is slumped after 60 minutes. The amount of decrease in the amount of slag was remarkable, and the slag collapsed and deformed, whereas the SP1 cement had better fluidity with the elapsed time than the SP2 cement, and the slag state was also good.

The same tendency was shown when the slag replacement rate was gradually increased. Even when the slag replacement rate was increased to 50%, 70%, and 80% and a certain amount of retarder was added at the same time, SP1 con was superior to SP2 con in terms of fluidity and slump state over time. Was there. Even when comparing SP1 con and SP2 con in which an admixture containing a certain amount of a retarding agent is added to the cement composition of "SG-50" as in Reference Example 5 and Reference Example 6, SP1 con is SP2 con. The slump condition was better than that.

As in Example 1 and Comparative Example 1, SP1 con and SP2 con in which an admixture containing a certain amount of retarder was added to the cement composition of "SG-70" having a slag substitution rate of 70% were compared. In this case, the slump collapsed and deformed in the slump state after 60 minutes, whereas the slump collapse was not observed in the SP1 con, and the excellent slump state was maintained. Further, the SP1 con was superior to the SP2 con in the fluidity with the elapsed time.

As in Example 2 and Comparative Example 2, SP1 con and SP2 con in which an admixture containing a certain amount of a retarder was added to the cement composition of "SG-80" having a slag substitution rate of 80% were compared. In this case, the SP2 cement not only collapsed and deformed in the slag state after 60 minutes, but also the amount of decrease in the slag after 60 minutes was remarkable. On the other hand, the SP1 con did not observe the collapse of the slump, maintained an excellent slump state, and also had good fluidity with the elapsed time.

As in Example 3 and Comparative Example 3, SP1 and SP2 cons, in which a certain amount of retarder and an admixture containing a certain amount of retention aid are added to the cement composition of "SG-80", are compared. However, while the slump collapsed and deformed in the slump state after 60 minutes, the SP1 control did not observe the collapse of the slump and maintained an excellent slump state. Further, the SP1 con was superior to the SP2 con in the fluidity with the elapsed time.

As described above, by using the admixture specified in the present invention for concrete containing a large amount of SCM admixture, it was possible to suppress the decrease in fluidity and state with the elapsed time. This can maintain the workability of concrete and extend the pot life.

By using the admixture specified in the present invention for concrete containing a large amount of SCM admixture, it is possible to suppress a decrease in fluidity over time and maintain a slump state. Therefore, the admixture specified in the present invention is also used for concrete containing a large amount of SCM admixture such as mass concrete such as dams, watertight concrete such as hydraulic facilities, and marine concrete such as marine piers and submerged boxes. This makes it possible to maintain good fresh properties for these concretes.

Claims (11)

It comprises a polycondensate having at least one structural unit (I), at least one structural unit (II), and at least one structural unit (III).
The structural unit (I) is an aromatic moiety having a polyether side chain having an alkylene glycol unit, however, the number of ethylene glycol units in the polyether side chain is 9 to 41, and the ethylene glycol. The content of the unit is more than 80 mol% with respect to all the alkylene glycol units in the polyether side chain.
The structural unit (II) is an aromatic moiety having at least one phosphate ester group and / or a salt thereof, provided that the value of the molar ratio of the structural unit (I) to the structural unit (II) is , 0.3-4,
The structural unit (III) is at least one methylene unit (-CH _2- ), and the methylene unit is bound to two aromatic structural units, the structural unit (I) and the structural unit (II). Here, the aromatic structural units are independent of each other and are the same or different .
The mass average molecular weight Mw of the polycondensate containing the structural units (I), (II) and (III) is in the range of 3,000 to 50,000 , and
An admixture for concrete containing a high amount of SCM admixture , which has a substitution rate of SCM admixture with respect to cement of 70% or more . The polycondensate further comprises at least one structural unit (IV).
The structural unit (IV) is represented by an aromatic structural unit different from the structural unit (I) and the structural unit (II).
The methylene unit is bound to three aromatic structural units, that is, the structural unit (I), the structural unit (II), and the structural unit (IV), where the aromatic structural units are independent of each other. And they are the same or different, and
The miscibility according to claim 1, wherein the polycondensate containing the structural units (I), (II), (III) and (IV) has a mass average molecular weight Mw in the range of 3,000 to 50,000. Agent. The admixture according to claim 1 or 2, further comprising a retention aid. The mixture according to claim 3, wherein the retention aid is a copolymer obtained by polymerizing a hydrolyzable monomer, an ethylenically unsaturated monomer containing a polyoxyalkylene group, and a cement-adsorbing monomer. Agent. The third aspect of the present invention, wherein the retention aid is a copolymer obtained by polymerizing a hydrolyzable monomer and an ethylenically unsaturated monomer containing a polyoxyalkylene group without containing a cement-adsorbing monomer. Admixture. The admixture according to any one of claims 1 to 5, further comprising a retarder selected from the group consisting of oxycarboxylic acids, oxycarboxylates, saccharides and sugar alcohols. The one according to any one of claims 1 to 6, which is applied to concrete containing a high amount of blast furnace slag as an SCM admixture and having a replacement ratio of the blast furnace slag with respect to cement of more than 60%. Admixture. The one according to any one of claims 1 to 6, which is applied to concrete containing a high amount of silica fume as an SCM admixture and having a substitution rate of the silica fume with respect to cement of more than 20%. Admixture. The one according to any one of claims 1 to 6, which is applied to concrete containing a high amount of fly ash as an SCM miscible material and which contains fly ash as a material and has a replacement ratio of the fly ash with respect to cement of more than 20%. Admixture. An admixture-containing composition comprising the admixture according to any one of claims 1 to 9 and CSH-based fine particles as a curing accelerator. A cement composition containing the admixture according to any one of claims 1 to 9.