JP2019112249A - Admixture for concrete highly containing scm additive agent, admixture-containing composition and cement composition containing the same - Google Patents

Abstract

To provide an admixture capable of suppressing reduction of followability and state with the lapse of time even when used for concrete containing a large amount of a SCM additive agent, and an admixture-containing composition and a cement composition containing the same.SOLUTION: There is provided an admixture for concrete highly containing a SCM additive agent containing a polycondensated article having following (I) to (III): (I) at least one structural unit, which is an aromatic part having a polyether side chain having 9 to 41 ethylene glycol units, (II) at least one structural unit, which is an aromatic part having at least one phosphoric acid ester group, and (III) at least one methylene unit (-CH-), and having mass average molecular weight Mw of the polycondensated article in a range of 3,000 to 50,000.SELECTED DRAWING: None

Description

  The present invention relates to admixtures for use in concretes with high SCM admixture content, in particular chemical admixtures for concrete. The present invention also relates to admixture containing compositions and cement compositions comprising such admixtures.

  For a cement composition containing cement such as concrete, cement, water, fine aggregate, coarse aggregate and the like are usually used, and as necessary, admixture materials such as blast furnace slag, silica fume and fly ash are blended. Such admixtures have potential hydraulicity or pozzolanic activity, and are generally referred to as SCM (Supplementary Cementitious Materials) admixtures as supplementary cement materials to be blended into concrete.

  The SCM admixture is a substance that hardens by latent hydraulicity or pozzolanic activity by the stimulation of alkali, and is a form previously mixed with cement such as blast furnace slag cement, silica cement, fly ash cement, or a separate SCM admixture It is conventionally used as a cement mixed material in the form of mixing it with cement.

  By blending such an SCM additive into cement, excellent effects such as suppression of heat of hydration, improvement of water tightness, suppression of alkali-silica reaction, and suppression of chloride ion penetration are expected. The specifications of the SCM admixture are specified in the JIS standards, and in the standards of JIS R 5211: 2009, JIS R 5212: 2009, JIS R 5213: 2009, Class A, Class B based on the amount to be blended in cement , C class. The upper limit of blast furnace slag is 70 mass%, silica is 30 mass%, and fly ash is 30 mass% with respect to the cement mass, respectively.

  However, most of SCM admixtures actually used as SCM admixtures to be blended in cement are blast furnace slag type B (more than 30% by mass of blast furnace slag and 60% by mass or less), and such SCM Its use is avoided due to the disadvantages of compounding admixtures, such as delayed setting, accelerated neutralization, loss over time, stability of quality, high cost etc. With regard to the delay of condensation, although the addition of a early strengthening material or an alkaline stimulant alleviates to some extent, the problem of loss over time has not been solved.

  On the other hand, in recent years, in order to use SCM admixtures more actively, for example, to replace cement or assist cement hydraulicity, for the purpose of effectively utilizing industrial waste and reducing environmental impact, for example, in 2013 At the Japan Concrete Institute, it has been studied at the “Study Committee on Evaluation and Construction of Impact on Concrete Performance by Admixture Active Utilization” (Non-Patent Document 1). From the viewpoint of further effective utilization of industrial waste, there is also a demand for use near the upper limit value of the mixing ratio of the SCM admixture or at a high rate exceeding the upper limit value. In addition, in the case where the curing action is insufficient by alkali stimulation of cement, a method of additionally adding and curing an alkali stimulation material such as water glass is also tried.

  The amount of these SCM admixtures does not affect the workability or improves the workability when the amount is about B according to the above-mentioned JIS standard, but the flowability and the state of the concrete with the elapsed time It is said that the tendency of fresh concrete to have a suitable viscosity and the property that the material flows without being separated, which tends to flow together, is simply lowered. On the other hand, it is reported that such a tendency becomes remarkable when using a large amount of SCM admixture. In particular, when fly ash is used, although the amount of dispersant added is generally small, combined with the decrease in fluidity with elapsed time, the viscosity of the concrete becomes high, making it difficult to handle and fill. Is known (Non-Patent Document 2).

When such SCM admixtures are added to concrete at a high content, various additives for adjusting the properties required according to the purpose of use, as well as appropriately adjusting the composition of the concrete material, For example, admixtures (dispersants) are used. Non-Patent Document 3 describes the use of a polycarboxylic acid-based dispersant having a specific chemical structure in concrete containing a high content of blast furnace slag. In Non-Patent Document 3, since Ca ²⁺ ions supplied from cement are specifically adsorbed to blast furnace slag and an adsorption site is formed, in concrete containing only cement and concrete containing blast furnace slag, the adsorption behavior of the dispersant and It suggests that the dispersion behavior is different. In addition, Non-Patent Document 3 also suggests that the adsorption behavior and the dispersion behavior are influenced by the chemical structure of the dispersant. However, the relationship between the type of dispersant and its chemical structure, and the flowability and the state with the passage of time of concrete containing a high content of SCM admixture is not mentioned.

Report of Research Committee on Impact Evaluation and Construction on Concrete Performance by Active Use of Admixture Report, Japan Concrete Institute, August 2013 JCI Annual Conference 1999, Vol.21, No.2, p115-120 Cement and concrete Proceedings, "Adsorption behavior of polymeric dispersants on high blast furnace slag content cement" 2011, Vol. 65, p 27-32

  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, an admixture containing the same, and a cement containing the same It is intended to provide a composition.

  As a result of intensive studies 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 condition with elapsed time, and an admixture-containing composition and a cement composition containing the same can be obtained.

That is, the gist configuration of the present invention is as follows.
[1] 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, provided that the number of ethylene glycol units in the polyether side chain is 9 to 41, and the ethylene glycol unit The content of units 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 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 bonded to two aromatic structural units, the structural unit (I) and the structural unit (II) Wherein said aromatic structural units are, independently of one another, identical or different, and
The admixture for SCM admixture high content concrete whose mass average molecular weight Mw of the polycondensate containing the said structural unit (I), (II) and (III) is the range of 3,000-50,000.
[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 bonded to the three aromatic structural units of the structural unit (I), the structural unit (II) and the structural unit (IV), wherein the aromatic structural units are independent of each other Identical or different, and
The weight 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 as described in the above [1]. Admixture.
[3] The admixture according to the above [1] or [2], further comprising a retention aid.
[4] The above-mentioned [3], wherein the holding assistant is a copolymer obtained by polymerizing a hydrolyzable monomer, an ethylenically unsaturated monomer containing a polyoxyalkylene group, and a cement-adsorbable monomer. Admixture as described in.
[5] The above-mentioned [4], wherein the retention aid does not contain a cement-adsorbable monomer, and is a copolymer formed by polymerizing a hydrolyzable monomer and an ethylenically unsaturated monomer containing a polyoxyalkylene group. The admixture as described in 3].
[6] The admixture according to any one of the above [1] to [5], further comprising a retarder selected from the group consisting of oxycarboxylic acids, oxycarboxylates, saccharides and sugar alcohols. .
[7] Any of the above-mentioned [1] to [6], which is applied to SCM admixture high content concrete containing blast furnace slag as SCM admixture, and the substitution ratio of said blast furnace slag to cement is over 60% Admixture as described in or one.
[8] Any of the above-mentioned [1] to [6] which is applied to SCM admixture high content concrete containing silica fume as SCM admixture and having a substitution ratio of said silica fume to cement exceeding 20% Admixture as described in or one.
[9] Any of the above-mentioned [1] to [6] which is applied to SCM admixture high content concrete containing fly ash as an SCM admixture, and the replacement ratio of the fly ash to cement is more than 20% Admixture as described in or one.
[10] An admixture-containing composition comprising the admixture according to any one of the above [1] to [9] and C-S-H-based fine particles as a curing accelerator.
[11] A cement composition comprising the admixture according to any one of the above [1] to [9].

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

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

(SCM high admixture content concrete)
In the present invention, SCM high admixture content concrete means concrete having a large amount of SCM admixture (subtractive hydraulic property or auxiliary cement substance having pozzolanic activity) to be blended in cement, specifically, JIS R 5211: 2009, JIS R 5212: 2009, JIS R 5213: A concrete that contains SCM admixture that is more than the upper limit of the amount belonging to Class C or defined in Class C according to the standards of 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 Amount of concrete means more than 20% by mass of concrete. In addition, the amount of SCM admixture blended into cement is synonymous with the substitution rate of SCM admixture to cement, and specifically means the content of SCM admixture in the total amount of cement and SCM admixture. Do.

A blast furnace slag means the fine powder of the blast furnace slag composition whose brane specific surface area is 3,000-10,000 cm < ² > / g, and the blast furnace slag fine powder prescribed | regulated to JISA6206: 2013 is preferable. JIS A 6206: 2013 exemplifies blast furnace slag fine powder 3000, 4000, 6000, 8000 classified into types by brane specific surface area, and among these, blast furnace slag fine powder 4000 is preferable from the viewpoint of supply surface and cost. More preferable.

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

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

[Admixture]
The admixture according to the present invention is an admixture containing SCM admixture-rich concrete and comprises at least one structural unit (I), at least one structural unit (II), and at least one structural unit (III). Containing a polycondensate having
Structural unit (I) is an aromatic moiety having a polyether side chain having an alkylene glycol unit, provided that the number of ethylene glycol units in the polyether side chain is 9 to 41, and The content is more than 80 mol%, relative to all alkylene glycol units in the polyether side chain,
Structural unit (II) is an aromatic moiety having at least one phosphate group and / or a salt thereof, provided that the molar ratio of structural unit (I) to structural unit (II) is 0. 0. 3-4,
Structural unit (III) is at least one methylene unit (-CH _2- ), and the methylene unit is bonded to two aromatic structural units Y of the structural unit (I) and the structural unit (II) Wherein the aromatic structural units Y are, independently of one another, identical or different and
The mass average molecular weight Mw of the polycondensate containing 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 the decrease in fluidity and state with elapsed time. Therefore, it becomes possible to maintain the workability of concrete, and also to extend the pot life.

<Structural unit (I)>
Structural unit (I) has proven to be advantageous to have a minimum polyether side chain length in order to obtain a reasonable dispersing action in cement binder systems, in particular in concrete. Very short chains are not preferred economically. This is because the dispersibility of the admixture is low and the feed amount required to obtain the dispersing action is increased, while, if the polyether side chain of the polycondensate is too long, such admixture is caused. Rheological properties of the concrete made with the agent (high viscosity). The content of ethylene glycol units in the polyether side chain is preferably more than 80 mol% with respect to all the alkylene glycol units in the polyether side chain, in order to make the polycondensate product sufficiently soluble. It is more preferably more than 85 mol%, still more preferably more than 90 mol%, and most preferably more than 95 mol%.

  The aromatic moiety in structural unit (I) has one or more polyether side chains, preferably one polyether side chain. The structural units (I) are, independently of one another, identical or different. This means that one or more of the structural units (I) can be present in the polycondensate. The structural units (I) can differ, for example, in the type of polyether side chains, in the type of aromatic structures.

  The structural unit (I) is derived from the respective aromatic monomer, which is an aromatic monomer having a polyether side chain containing an alkylene glycol unit, the side chain length and the proportion of ethylene glycol in the side chain Meet the above requirements for This monomer is incorporated into the polycondensation product by the formaldehyde of the monomer and the monomer that becomes the structural unit (I) when being incorporated into the polycondensation product by the polycondensation reaction. In particular, structural unit (I) is an aromatic monomer derived from the absence of the two hydrogen atoms (formed with one oxygen atom from formaldehyde) which are abstracted from the monomer during the polycondensation reaction It is different from

The aromatic moiety in structural unit (I) is preferably a substituted or unsubstituted aromatic moiety having a polyether side chain according to the present invention, the aromatic being a benzene ring or a naphthalene ring May be One or more polyether side chains, preferably one or two polyether side chains, most preferably one polyether side chain may be present in structural unit (I). In this context "substituted aromatic moiety" preferably denotes any substituent other than a polyether side chain or other than a polyether side chain according to the invention. The substituent is preferably a C ₁ -C ₁₀ alkyl group, 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 substituted derivatives of benzene. The aromatic moiety in the structural unit (I) may be a heteroaromatic structure containing an atom different from carbon, such as oxygen (in furfuryl alcohol), but an atom of the aromatic ring structure is 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, more preferably 12 to 23. The relatively short polyether side chain length contributes to the good rheological properties of the concrete made with the admixture according to the invention comprising the polycondensate having the structural unit (I), in particular obtaining a low plastic viscosity Be On the other hand, polyether side chain lengths which are too short are not economically desirable because the dispersing action is reduced and the amount of supply required to obtain a certain level of workability (e.g. slump in concrete tests) is increased.

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

  Structural unit (I) can be derived from the following monomers, but is not limited thereto. For example, ethoxylated derivatives of aromatic alcohols or amines are preferred, phenol, cresol, resorcinol, catechol, hydroquinone, naphthol, furfuryl alcohol or ethoxylated derivatives of aniline are more preferred, ethoxylated phenols in particular preferable. Preferably, resorcinol, catechol and hydroquinone have two polyether side chains. Resorcinol, catechol and hydroquinone can in each case have only one polyether side chain. 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) preferably has the following general formula (Ia):

(In formula (Ia),
A is the same or different and is represented by a substituted or unsubstituted aromatic or heteroaromatic compound having 5 to 10 carbon atoms,
B is the same or different and is N, NH or O, in which case if B is N then n is 2 and if B is NH or O then n is 1 ,
R ¹ and R ² are, independently of one another, identical or different, branched or linear C _{1 to} C ₁₀ alkyl group, C _{5 to} C ₈ cycloalkyl group, aryl group, hetero Aryl group or H, provided that the number of ethylene glycol units in the polyether side chain (R ¹ and R ² are H) is 9 to 41, and the proportion of ethylene glycol units is the polyether side chain More than 80 mol%, relative to all alkylene glycols in
a is the same or different, is an integer of 12 to 50, and X is the same or different, and a linear or branched C _{1 to} C ₁₀ alkyl group, C ₅ -C ₈ cycloalkyl group, an aryl group, represented by a heteroaryl group, or H). In the above-mentioned formula (Ia), a polycondensate which is a main component of the admixture in the present invention is formed by bonding the group “A” to a methylene unit of the structural unit (III) described later.

  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. And substituted derivatives of benzene or benzene.

  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, 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 in particular, a polycondensate of phenyl polyalkylene glycol preferable. Phenyl polyalkylene glycols can be obtained relatively easily, are also economically viable, and the reactivity of aromatic compounds is also relatively good.

The structural unit (I) is preferably derived from a 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 Alkylene having 3 carbon atoms, provided that the proportion of ethylene glycol units (Z ¹ = ethylene) is 80 mol% relative to all alkylene glycol units in the polyether side chain (Z ¹ O) _n More than, preferably more than 85 mol%, more preferably more than 90 mol%, most preferably more than 95 mol%. In Formula (V) above, the aromatic structural moiety of “C ₆ H ₃ ” is bonded to a methylene unit of Structural Unit (III) described later.

The substitution pattern in the aromatic benzene unit (C ₆ H ₃ in the above formula (V)) is determined by the position (1st position) of the oxygen atom bonded to the benzene ring by the activation action (electron donating action) of the oxygen atom Are mainly ortho substitution position (2 position) and para substitution position (4 position).

<Structural unit (II)>
The structural unit (II) brings an anionic group to the polycondensate (from phosphoric acid ester to its acid or salt form), which is the positive charge present on the surface of cement particles in the aqueous cement dispersion. Interfere with and are strongly alkaline. Due to electrostatic attraction, the polycondensate adsorbs to the surface of the cement particles and the cement particles are dispersed. Here, the term "phosphate" preferably includes phosphate monoester (PO (OH) ₂ (OR) ₁ ), phosphate diester (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, which reacts to form an ester with phosphoric acid. The group R preferably has an aromatic moiety. Monoesters are usually the main products of the phosphorylation reaction.

  The term "phosphorylated monomer" refers to the reaction product of an aromatic alcohol with phosphoric acid, polyphosphoric acid or phosphorous oxide, and the reaction of an aromatic alcohol with a mixture of phosphoric acid, polyphosphoric acid and phosphorous oxide The product is included.

  The proportion of phosphoric monoesters is preferably more than 50% by weight, based on the sum of all phosphoric esters. The content of structural units (II) derived from phosphoric monoesters is preferably more than 50% by weight, based on the sum of all structural units (II).

  In the structural unit (II), the aromatic moiety preferably contains one phosphoric ester group and / or a salt thereof. This means that the use of aromatic monoalcohols is preferred. The structural unit (II) may have more than one and preferably two phosphate ester groups and / or salts thereof. In this case, at least one aromatic dialcohol or aromatic polyalcohol is used. The structural units (II) are, independently of one another, identical or different. This means that one or more of the structural units (II) can be present in the polycondensate.

  Structural unit (II) in the polycondensate is an aromatic moiety having at least one phosphate ester group and / or a salt thereof, provided that the value of molar ratio of structural unit (I) to 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. The range of this molar ratio is sufficient initial dispersibility of polycondensate (relatively high content of structural unit (II)), and sufficient slump retention property (relatively high content of structural unit (I)) It is advantageous because it can be achieved in concrete samples.

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

  The aromatic moiety in the 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 a benzene ring even if it is a benzene ring It may be a ring. One or more phosphate groups and / or salts thereof being present in the structural unit (II), preferably one or two phosphate groups and / or salts thereof being present, most preferably One phosphate ester group and / or a salt thereof may be present. The aromatic moiety of 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 is It is a substituted benzene or benzene having 6 carbon atoms. The aromatic moiety in the structural unit (II) may be a heteroaromatic structure containing an atom different from carbon, such as oxygen (in furfuryl alcohol), but the atom in the aromatic ring structure is a carbon atom Is preferred.

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

  The structural units (II) derived from the respective phosphorylated aromatic alcohol monomers are different from those described above due to the abstraction of two hydrogen atoms from each monomer. Such structural units (II) are derived from, for example, the following compounds, but are not limited thereto. For example, a phosphorylated product of an aromatic alcohol or a phosphorylated product of hydroquinone is preferable, and phenoxyethanol phosphate (aromatic alcohol: phenoxyethanol), phenoxydiglycol phosphate (aromatic alcohol: phenoxydiglycol), (methoxyphenoxy) ethanol phosphate (Aromatic alcohol: (methoxyphenoxy) ethanol), methyl phenoxy ethanol phosphate (aromatic alcohol: methyl phenoxy ethanol), nonylphenol phosphate (aromatic alcohol; nonylphenol), bis (β-hydroxyethyl) hydroquinone ether phosphate (hydroquinone: bis (β -Hydroxyethyl) hydroquinone ether), bis (β-hydroxyethyl) hydroquinone agent Rujihosufeto (hydroquinone bis (beta-hydroxyethyl) hydroquinone ether) are more preferable, phenoxyethanol phosphate, phenoxy Siji glycol phosphate, bis (beta-hydroxyethyl) hydroquinone ether diphosphate is particularly preferred, and most preferably phenoxyethanol phosphate. Mixtures of the above mentioned monomers from which the structural unit (II) is derived may be used.

Usually, the main product (monoester of phosphoric acid and one equivalent of aromatic alcohol: PO.sub. (OH) during phosphorylation reaction (e.g. reaction of the above aromatic alcohol containing hydroquinone with phosphoric acid) It should be noted that, besides ₂ (OR) ₁ )), by-products are also formed. The by-products are, in particular, diesters of phosphoric acid and 2 equivalents of aromatic alcohol (PO (OH) (OR) ₂ ) or triesters of phosphoric acid and 3 equivalents of aromatic alcohol (PO (OR) ₃ ) The formation of triesters is not usually produced as temperatures above 150 ° C. are required. 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. The proportion 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 weight, preferably more than 65% by weight, 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) preferably has the following general formula (IIa):

(In the formula (IIa),
D is the same or different and is represented by a substituted or unsubstituted aromatic or heteroaromatic compound having 5 to 10 carbon atoms,
E is the same or different and is N, NH or O, and when E is N, m is 2 and when E is NH or O, m is 1.
R ³ and R ⁴ are, independently of one another, identical or different, and linear or branched C _{1 to} C ₁₀ alkyl group, C _{5 to} C ₈ cycloalkyl group, aryl group, Heteroaryl or H,
b is the same or different, is an integer of 0 to 10, and Ma is mutually independently, the same or different, and is represented by H or a cation equivalent. In the above formula (IIa), a polycondensate which is a main component of the admixture in the present invention is formed by bonding the group "D" to a methylene unit of the structural unit (III) described later.

  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, most preferably in the aromatic structure It is a substituted benzene or benzene having 6 carbon atoms.

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

In formula (IIa), R ³ and R ⁴ independently of each other are preferably H, methyl, ethyl or phenyl, more preferably H or methyl, particularly preferably H, and most preferably And 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) may be an acid having two acidic protons (Ma = H). Phosphoric 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" refers to any metal cation or ammonium cation (which can replace a proton) which may be substituted, but the molecule is electrically neutral. M is preferably NH ₄ , an alkali metal or 1⁄2 alkaline earth metal.

  The group A of the structural unit (Ia) and the group D of the structural unit (IIa) are, for example, independently of each other, phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2-methoxyphenyl It is preferably 3-methoxyphenyl or 4-methoxyphenyl, more preferably phenyl. 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 polycondensates Good. The groups B and E are preferably, independently of one another, O (oxygen).

The structural unit (II) is preferably an alkoxylated phenol phosphate as represented by the following general formula (VI), or an alkoxylated as represented by the following general formula (VII) Derived from hydroquinone phosphate ester:
^{_{- [C 6 H 3 -O- (}} Z 2 O) q -PO 3 M 2] - (VI)
_{- [[M 2 O 3 P-} (Z 3 O) r] -O-C 6 H 2 -O - [(Z 4 O) s -PO 3 M 2]] - (VII)

In any of the formulas (VI) and (VII), q, r and s are an integer of 1 to 5, preferably an integer of 1 to 2, more preferably 1, Z ² , Z ³ and Z ⁴ are And, independently of each other, alkylene having 2 to 5, preferably 2 to 3 carbon atoms, more preferably ethylene. M is, independently of one another, identical or different, H or a cation equivalent. The aromatic structural moiety of “C ₆ H ₃ ” in the above formula (VI) and the aromatic structural moiety of “C ₆ H ₂ ” in the above formula (VII) are methylene of structural unit (III) described later, respectively. Combined into a unit.

The esters of the general formulas (VI) and (VII) may be acids with two acidic protons (M = H). The ester may also be present in deprotonated form, in which case the protons are replaced by cation equivalents. The ester may be partially deprotonated. The term cation equivalent is as described above and M is preferably NH ₄ , an alkali metal, or a 1/2 alkaline earth metal. Thus, for example, in the case of an alkaline earth metal having two positive charges, there must be a factor of 1/2 to guarantee neutrality (1/2 alkali metal), for example a metal When component "M" is Al ³⁺ , 1⁄3 Al is the cation equivalent. In addition, for example, a mixed cation equivalent having two or more types of metal cations may be used.

  Such alkoxylated phenol phosphates or alkoxylated hydroquinone phosphates are relatively easy to obtain and are economically desirable, and also the reactivity of aromatic compounds in the polycondensation reaction It is relatively good.

<Structural unit (III)>
Structural unit (III) is at least one methylene unit (—CH ₂ —), and the methylene unit is bonded to two aromatic structural units, structural unit (I) and structural unit (II) The aromatic structural units are, independently of one another, identical or different and correspond to the above-mentioned aromatic moieties in structural unit (I) and structural unit (II). The methylene units are 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). Structural unit (IV) is an aromatic structural unit of a polycondensate different from structural unit (I) and structural unit (II), and may be any aromatic structural unit. Further, when the structural unit (IV) is contained, the methylene unit in the structural unit (III) is bonded to three aromatic structural units of the structural unit (I), the structural unit (II) and the structural unit (IV) The aromatic structural units in structural unit (IV) are, independently of one another, identical or different. This means that one or more 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 the polycondensation reaction (two hydrogen atoms are withdrawn from each monomer). Examples of monomers from which the structural unit (IV) is derived include phenoxy alcohol, phenol, naphthol, aniline, benzene-1,2-diol, benzene-1,2,3-triol, 2-hydroxybenzoic acid, 2,3- 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.

  Structural unit (IV) may also be a structural unit similar to structural unit (I), differing only in the number of ethylene glycol units in the side chains. As such structural unit (IV), preferably, it is an aromatic moiety having a polyether side chain having an alkylene glycol unit, provided that the number of ethylene glycol units in the polyether side chain is 42 to 120, And the content of ethylene glycol units is a structural unit which is more than 80 mol% with respect to all the alkylene glycol units in the polyether side chain.

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

  The value of the molar ratio of ethylene glycol units from structural unit (I) to phosphoric acid ester units from structural unit (II) is preferably 11 to 40/1, and more preferably 12 to 35/1. And 13 to 30/1 are more preferable. To identify this molar ratio, the sum of all ethylene glycol units from structural unit (I) is calculated, also taking into account the presence of different types of structural units (I).

  The molar ratio of ethylene glycol units from structural unit (I) to phosphoric acid ester units from structural unit (II) is calculated to be at least 9 and at most 41 in structural unit (I) Alkylene glycol is combined with the value of the molar ratio of 0.3 to 4 of structural unit (I) to structural unit (II), and the minimum value is 9/8 (structural unit (I) / structural unit (II The short side chain of 9EO whose molar ratio value is 4), as well as the possibility that two phosphate groups may be present in structural unit (II)). On the other hand, in combination with 0.3 which is the lower limit value of the molar ratio of structural unit (I) / structural unit (II), the long side chain of 41 EO and the phosphate ester present in structural unit (II) The maximum value is obtained as 136.7 (41 / 0.3). If the molar ratio of ethylene glycol units from structural unit (I) to phosphoric acid ester units from structural unit (II) is lower than the lower limit (9/8), the phosphoric acid ester group is excessive, so a concrete test sample The slump retention at the end is worse. On the other hand, if this molar ratio is larger than the upper limit value (136.7), the adsorptivity to cement particles is too weak, so the water reduction characteristic (initial water reduction rate in the concrete test body) is not very good. Thus, the range of the molar ratio of the ethylene glycol unit from structural unit (I) to the phosphoric acid ester unit from structural unit (II) is in the range of 9/8 to 136.7, thereby giving a concrete test body In the above, an appropriate balance of the two characteristics of the slump retention and the water reduction rate can be obtained, and both the good water reduction rate and the good slump retention can be obtained. Also, the viscosity of the concrete can be lowered.

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

  Most preferred is a polycondensate in which structural unit (IV) 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 structural unit (IV) is 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, 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 combination of columns 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 an 80% by volume aqueous solution of HCO ₂ NH ₄ (0.05 mol / l) and 20% by volume of acetonitrile, others, injection volume: 100 μl, flow rate: 0.5 ml / min. Molecular weight calibration is performed with poly (styrene sulfonate) standards for UV detectors and poly (ethylene oxide) standards for RI detectors. Both standards can be purchased from PSS Polymer Standards Service in Germany. UV detection is used at 254 nm to determine the molecular weight of the polymer. UV detectors do not sense inorganic impurities, so they can only sense 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 polycondensate described above. The additional inclusion of retention aids suppresses the aging of the concrete and allows better control of the workability of the concrete over a longer period of time. As a result, it is possible to further suppress the deterioration of the fluidity and the 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.

  For example, a copolymer formed by polymerizing a hydrolyzable monomer, an ethylenically unsaturated monomer containing a polyoxyalkylene group, and a cement adsorptive monomer as one of such holding aids It is preferred to use combination 1).

(Hydrolyzable monomer)
The hydrolyzable monomer is preferably an ethylenically unsaturated monomer capable of forming a hydrolyzable monomer residue. As such a hydrolysable monomer, for example, alkyl (meth) acrylate such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate and the like;
Hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and the like;
And (meth) acrylamide and derivatives thereof; and maleic acid (mono) alkyl ester, maleic anhydride, maleimide, etc., but not limited thereto. These may be used alone or in combination of two or more.

(Ethylenic unsaturated monomer containing polyoxyalkylene group)
As an ethylenically unsaturated monomer containing a polyoxyalkylene group, a saturated monocarboxylic acid ester derivative such as polyethylene glycol mono (meth) acrylate, polypropylene glycol (meth) acrylate, polybutylene glycol (meth) acrylate, 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, methoxy polyethylene glycol mono (meth) acrylate, Methoxy polypropylene glycol mono (meth) acrylate, Xylopolybutylene glycol mono (meth) acrylate, methoxypolyethylene glycol polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol polybutylene glycol mono (meth) acrylate, methoxypolypropylene glycol polybutylene glycol mono (meth) acrylate, methoxypolyethylene glycol polypropylene glycol Polybutylene glycol mono (meth) acrylate, ethoxy polyethylene glycol mono (meth) acrylate, ethoxy polypropylene glycol mono (meth) acrylate, ethoxy polybutylene glycol mono (meth) acrylate, ethoxy polyethylene glycol polypropylene glycol mono (meth) acrylate, ethoxy polyethylene The Call polybutylene glycol mono (meth) acrylate, ethoxy polypropylene glycol polybutylene glycol mono (meth) acrylate, ethoxy polyethylene glycol polypropylene glycol polybutylene glycol mono (meth) acrylate, and higher alkoxy derivatives of the above polyoxyalkylene;
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, polypropylene glycol polybutylene glycol mono (meth) vinyl ether, polyethylene glycol polypropylene glycol polybutylene glycol mono (meth) vinyl ether, methoxy polyethylene glycol mono (meth) vinyl ether, methoxy polypropylene glycol mono (meth) vinyl ether, methoxy polybutylene glycol mono ( Meta) vinyl Ter, methoxy polyethylene glycol polypropylene glycol mono (meth) vinyl ether, methoxy polyethylene glycol poly butylene glycol mono (meth) vinyl ether, methoxy polypropylene glycol poly butylene glycol mono (meth) vinyl ether, methoxy polyethylene glycol polypropylene glycol poly butylene glycol mono (meth) vinyl ether , Ethoxypolyethylene glycol mono (meth) vinylether, ethoxypolypropylene glycol mono (meth) vinylether, ethoxypolybutylene glycol mono (meth) vinylether, ethoxypolyethyleneglycol polypropylene glycol mono (meth) vinylether, ethoxypolyethylene glycol polybutylene glycol Mono (meth) vinyl ether, ethoxy polypropylene glycol polybutylene glycol mono (meth) vinyl ether, and ethoxy polyethylene glycol polypropylene glycol polybutylene glycol mono (meth) vinyl ether;
(Meth) 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 (Meth) allyl ether, methoxypolybutylene glycol mono (meth) Allyl ether, methoxy polyethylene glycol polypropylene glycol mono (meth) allyl ether, methoxy polyethylene glycol poly butylene glycol mono (meth) allyl ether, methoxy polypropylene glycol poly butylene glycol mono (meth) allyl ether, methoxy polyethylene glycol polypropylene glycol poly butylene glycol mono (Meth) allyl ether, ethoxypolyethylene glycol mono (meth) allyl ether, ethoxypolypropylene glycol mono (meth) allyl ether, ethoxy polybutylene glycol mono (meth) allyl ether, ethoxy polyethylene glycol polypropylene glycol mono (meth) allyl ether, ethoxy Polyethylene glycol polybutylene Recall mono (meth) allyl ether, ethoxy polypropylene glycol polybutylene glycol mono (meth) allyl ether and ethoxy polyethylene glycol polypropylene glycol polybutylene glycol mono (meth) allyl ether;
Adducts of alkylene oxide and unsaturated alcohol, for example, polyethylene glycol mono (3-methyl-3-butenyl) ether, polyethylene glycol mono (3-methyl-2-butenyl) ether, polyethylene glycol mono (2-methyl-3-ether) Butenyl) ether, polyethylene glycol mono (2-methyl-2-butenyl) ether, polyethylene glycol mono (1,1-dimethyl-2-propenyl) ether, polyethylenepolypropylene 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, nonylalkoxypolyethyleneglycol mono (3-methyl-3-butenyl) ether, laurylalkoxypolyethyleneglycol mono (3-methyl-3-butenyl) ether, stearylalkoxypolyethyleneglycol mono (3-methyl-3-butenyl) ether and Phenoxy polyethylene glycol mono (3-methyl-3-butenyl) ether; and the like, but not limited thereto. The adduct of an alkylene oxide and an unsaturated alcohol is, for example, an adduct of 1 to 350 moles of an alkylene oxide and an unsaturated alcohol, for example, 3-methyl-3-buten-1-ol, 3-methyl-2-butene-. Adducts with unsaturated alcohols such as 1-ol, 2-methyl-3-buten-2-ol, 2-methyl-2-buten-1-ol and 2-methyl-3-buten-1-ol are mentioned But not limited thereto. The above-mentioned ethylenically unsaturated monomers containing a polyoxyalkylene group may be used alone or in combination of two or more.

Ethylenically unsaturated monomers containing such polyoxyalkylene groups can contain oxyalkylene groups having multiple side chain lengths. For example, comprising at least one ethylenically unsaturated carboxylic acid ester or alkenyl ether monomer comprising at least one C _2-4 oxyalkylene group having from 1 to 30 pieces of unit, at least one C ₂ of 31 to 350 pieces of unit _It may contain at least one ethylenically unsaturated carboxylic acid ester or alkenyl ether monomer containing a _-4 oxyalkylene group.

(Cement adsorptive monomer)
The cement adsorptive monomer is preferably an ethylenically unsaturated monomer having a carboxyl group, a sulfone group or a phosphonic group at the end. As the ethylenically unsaturated monomer having a carboxy group, unsaturated carboxylic acid monomers such as (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid and fumaric acid or salts thereof are preferable, and examples thereof include alkali metal salts and alkaline earth metals. Metalloid salts, ammonium salts, amine salts and the like can be mentioned. More preferably, it is (meth) acrylic acid or an alkali metal salt thereof, and still more preferably acrylic acid or its sodium salt. Examples of the ethylenically unsaturated monomer having a sulfone group include (meth) allyl sulfonic acid or salts thereof, such as alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts and the like, preferably (meth) allyl. It is a sodium salt of sulfonic acid, more preferably a sodium salt of methallyl sulfonic acid. As the ethylenically unsaturated monomer having a phosphonic group, mono (2-hydroxyethyl) (meth) acrylic ester phosphate, di- (2-hydroxyethyl) (meth) acrylic ester phosphate 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, more preferably 0.5: 1: 0.3 to 5: 1: 5.

  As another holding aid, for example, a copolymer obtained by polymerizing the above-mentioned hydrolyzable monomer and the above-mentioned ethylenically unsaturated monomer containing the polyoxyalkylene group without containing the above-mentioned cement-adsorbable monomer It is preferred to use a combination (copolymer 2). That is, the copolymer 2 does not have a structural unit derived from the above-described cement-adsorbable monomer, and includes a structural unit derived from the above-described hydrolyzable monomer and the above-described polyoxyalkylene group. A copolymer comprising structural units derived from ethylenically unsaturated monomers.

  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 10: 1, more preferably 1: 1 to 9: 1.

<Retardant>
The admixture according to the present invention may, if necessary, be an oxycarboxylic acid or oxycarboxylate as a delaying component having a delay effect in order to adjust the setting characteristics of the resulting cement composition and the flow retention of slump flow. , A retarder selected from the group consisting of sugars and sugar alcohols may be included. As the oxycarboxylic acid, citric acid, gluconic acid, fumaric acid and the like are preferable, and as the salt thereof, an alkali metal salt is preferable. Further, as saccharides, maltose, lactose, xylose, sucrose and the like are preferable, and as sugar alcohols, sorbitol, xylitol, erythritol and the like are preferable. The retarder may be contained as part of the components of the admixture of one embodiment, or may be added to concrete separately from the admixture of one embodiment. When making it a part of ingredient of admixture of one embodiment, it is limited to the range which does not inhibit an effect of the present invention, and it is preferred to contain 1-10 mass% to admixture of one embodiment.

[Admixture-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 to be a one-part type state in which the curing accelerator is contained as a part of the components of the above-mentioned admixture, and the curing accelerator is the above-mentioned admixture and May be in the form of a separately added two-component type (separate type). It is preferable that such a hardening accelerator is a hardening accelerator which disperse | distributed CSH type | system | group nanoparticle as CSH type microparticles | fine-particles. A hardening accelerator having dispersed therein C-S-H-based nanoparticles is preferable because the main component is the same as the cement hydrate. The dispersant for dispersing the C—S—H-based nanoparticles is not particularly limited, and for example, at least one selected from polyalkylene glycol having a functional group at the end, a water-soluble comb polymer and a polyaryl ether compound One type is preferable.

The calcium silicate hydrate which comprises a C-S-H type | system | group nanoparticle has the following general formula (VIII)
dCaO · SiO ₂ · eH ₂ O (VIII)
(In the formula (VIII),
d is preferably 0.1 ≦ d ≦ 2, more preferably 0.66 ≦ d ≦ 1.8,
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 analytical ultracentrifugation.

Calcium silicate hydrates include, for example, phosphalite, hirebrandite, zonolite, feline stone, monoclinic tobermorite, 9 Å-tobermorite (riverside stone), 11 Å-tobermorite, 14 Å-tobermorite (prombierite), jennisite And metagennite, calcium chondrite, aphyllite, α-C ₂ SH, dellite, japheite, rosenhaan stone, quillaite stone, and sourneite. In particular, Zonotrite, 9 Å-tobermorite (riverside stone), 11 Å-tobermorite, 14 Å-tobermorite (Prombierite), jenniite, metagenite, aphyrite, and japheite 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 weight average molecular weight Mw of more than 500,000 g / mol, preferably more than 1,000,000 g / mol.

  Such curing accelerators 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 use 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, drying shrinkage reducing agents, accelerators, foaming agents, antifoaming agents, antirust agents, quick-setting agents, high water solubility Molecular substances and the like can be mentioned. Other additives may be contained as 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 making it a part of component of the admixture based on this invention, it is limited to the range which does not inhibit the effect of this invention, and it is preferable to contain 1-20 mass% with respect to the admixture based on this invention.

<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, low heat cement from the viewpoint of versatility. In the present invention, ordinary portland cement is particularly preferable in terms of the durability of the obtained cement composition and the cost due to the reduced addition amount of the cement additive.

(Other powder)
Fine powder admixtures such as limestone powder, calcium carbonate and expansive additives can be added as a partial substitution or addition of the cement contained in the cement composition as a powder having no latent hydraulic property or pozzolanic activity. . These powders suppress the material separation, maintain appropriate viscosity and high flowability, and the compounding amount in 1 m ^{3 of} cement composition is 0 to the extent that the effects of the present invention are not impaired. It is preferably 100 kg / m ³ .

(aggregate)
In cement compositions according to the invention, it is preferred to use natural aggregates. It is preferable to use sea sand, land sand, mountain sand, crushed sand, etc. as fine aggregate, and it is preferable to use mountain gravel, river gravel, sea gravel, crushed stone as coarse aggregate. Concrete using these aggregates is likely to obtain the effects of the additive. In addition, the aggregate particle size is preferably aggregate having a suitable particle size distribution from the viewpoint of securing flowability, and the particle size distribution of the aggregate specified in the aggregate of JIS A 5308 Appendix A ready mixed concrete is preferred. It is preferable to have.

<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 blast furnace slag is contained as the SCM admixture, it is applied to SCM admixture high content concrete in which the substitution ratio of blast furnace slag to cement is over 60%. Also, for example, when silica fume is contained as an SCM admixture, it is applied to SCM admixture high concrete containing a substitution ratio of silica fume to cement over 20%, and when containing fly ash as an SCM admixture, cement Applied to concretes containing a high amount of SCM admixture, in which the percentage of substitution of fly ash relative to 20% exceeds 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 the same as that of the prior art.

  The cement composition containing the admixture according to the present invention is preferably usable as a mass concrete such as a dam, a water-tight concrete such as a hydraulic facility, or a marine concrete such as a sea bridge pier or a sinking box. In the above, the excellent effect of mixing the SCM admixture is obtained, and it is preferable in order to maintain the flowability and the state of the SCM admixture-rich concrete.

<Manufacturing of concrete>
The cement composition according to the present invention can be manufactured by a conventionally known method, for example, according to the concrete standard specification book established by the Japan Society of Civil Engineers and the standard specification of building construction prepared by the Japan Architectural Institute of Japan. It can be produced by known equipment and known methods. Specifically, after the admixture according to the present invention is added to kneading water in advance, other raw materials such as cement, aggregate and the like are added to the mixer for manufacturing, or all the raw materials contained in the cement composition The method of putting into a mixer collectively and manufacturing is preferable. The cement composition according to the present invention is preferably produced in a ready-mixed plant in accordance with JIS A 5308.

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

  Concrete was manufactured from the cement composition of the compounding conditions shown in Table 2 using the use materials shown in Table 1. The slump and slump flow of the obtained concrete were measured, and the state of the slump was visually observed.

<Material used>

<Composition of cement composition>

<How to mix>
Among the above materials, cement (C), SCM admixture (SG) and aggregates (S, G) are introduced into a two-axis forced mixer mixer SD-55 made by Pacific Kiko Co., Ltd. Once mixing is stopped, water (W), and a solution in which admixture (SP1, SP2), retarder (RT) and retention aid (RA) are mixed in advance are added, and the mixture is further kneaded for 60 seconds, and concrete is Obtained. The addition amounts of the admixture (SP1, SP2), the retarder (RT) and the retention aid (RA) were adjusted according to the amounts shown in Table 3 and adjusted to the target slump value.

<Measurement and evaluation>
The slump value and slump flow value immediately after mixing (0 minutes) and after 60 minutes were measured, and the state of the slump visually observed. Evaluation of each item was performed as follows.

<Slump>
The slump value was measured based on JIS A 1101. It classified into following three according to the fall amount of the slump after 60 minutes immediately after mixing, and evaluated as fluidity | liquidity accompanying elapsed time.
"◎" excellent: less than 5 cm "○" good: 5 cm or more and less than 10 cm "×" defect: 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 classified into the following three by visual observation of the measurer and evaluated as a state.
"◎" excellent: "一体" integrally deformed as "good": the slump collapsed slightly, but "×" separated as a whole integrated: 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 kon”) and the concrete to which SP 2 is added (hereinafter referred to as “SP2 kon”), the slag replacement ratio is 0 as in Reference Example 1 and Reference Example 2 When SP1 kon and SP2 kon were respectively produced from the cement composition of "SG-0" which is%, the reduction amount of the slump after 60 minutes was less than 5 cm in all. Therefore, both were excellent in fluidity with elapsed time, and no separation of slump state was observed. When SP1 kon and SP2 kon are respectively prepared from the cement composition of “SG-50” having a slag substitution rate of 50% as in Reference Example 3 and Reference Example 4, the SP2 kon is a slump after 60 minutes. While the slump collapsed and deformed, the SP1 kon had better flowability with elapsed time than the SP2 kon, and moreover, the slump condition was also good.

  The same tendency was shown when the slag replacement rate was increased sequentially. Even if the slag replacement rate is increased to 50%, 70% and 80% and compared under the conditions where a certain amount of retarder is added at the same time, SP1 kon is superior to SP2 kon in fluidity and slump condition with elapsed time It was As in Reference Example 5 and Reference Example 6, even when SP1 kon and SP2 kon in which an admixture containing a certain amount of retarding agent is added to the cement composition of "SG-50" and SP2 kon are compared, SP1 kon is SP2 kon The slump condition was better than that.

  As in Example 1 and Comparative Example 1, SP1con and SP2con were compared 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%. In the case of SP2, the slump collapsed and deformed in the slump state after 60 minutes, whereas the slump was not observed in SP1 and the slump maintained an excellent slump state. Moreover, SP1 kon was superior to SP2 kon in fluidity with elapsed time.

  As in Example 2 and Comparative Example 2, SP1con and SP2con were compared in which an admixture containing a certain amount of retarder was added to the cement composition of "SG-80" having a slag substitution rate of 80%. In the case of the SP2 controller, not only the slump collapsed and deformed in the slump state after 60 minutes, but also the decrease amount of the slump after 60 minutes was remarkable. On the other hand, no collapse of the slump was observed, and the SP1 controller maintained an excellent slump state, and furthermore, the fluidity with the elapsed time was also good.

  As in Example 3 and Comparative Example 3, comparing the SP1con and SP2con obtained by adding an admixture containing a certain amount of retarder and a certain amount of retention aid to the cement composition of "SG-80" Even in the slump condition after 60 minutes, the slump was deformed and deformed in the SP2 condition, whereas the slump was not observed in the SP1 condition, and the slump condition remained excellent. Moreover, SP1 kon was superior to SP2 kon in fluidity with elapsed time.

  As described above, by using the admixture defined in the present invention for concrete containing a large amount of SCM admixture, it was possible to suppress the deterioration of the fluidity and the state with the lapse of time. This can lead to maintenance of the workability of the concrete and further prolongation of the pot life.

  By using the admixture defined in the present invention for the concrete containing a large amount of SCM admixture, it is possible to suppress the decrease in fluidity with elapsed time and maintain the 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 dam, water-tight concrete such as hydraulic facility, and marine concrete such as sea bridge piers and sinking boxes. Thereby, it becomes possible to keep the fresh property for these concretes well.

（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) preferably has the following general formula (IIa):

(In the formula (IIa),
D is the same or different and is represented by a substituted or unsubstituted aromatic or heteroaromatic compound having 5 to 10 carbon atoms,
E is the same or different and is N, NH or O, and when E is N, m is 2 and when E is NH or O, m is 1.
R ³ and R ⁴ are, independently of one another, identical or different, and linear or branched C _{1 to} C ₁₀ alkyl group, C _{5 to} C ₈ cycloalkyl group, aryl group, Heteroaryl or H,
b is the same or different, is an integer of 0 to 10, and Ma is mutually independently, the same or different, and is represented by H or a cation equivalent. In the above formula (IIa), a polycondensate which is a main component of the admixture in the present invention is formed by bonding the group "D" to a methylene unit of the structural unit (III) described later.

The phosphoric acid ester represented by the formula (IIa) may be an acid having two acidic protons (Ma = H). Phosphoric 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" refers to any metal cation or ammonium cation (which can replace a proton) which may be substituted, but the molecule is electrically neutral. Ma is preferably NH ₄ , an alkali metal or a half alkaline earth metal.

Claims (11)

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, provided that the number of ethylene glycol units in the polyether side chain is 9 to 41, and the ethylene glycol unit The content of units 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 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 bonded to two aromatic structural units, the structural unit (I) and the structural unit (II) Wherein said aromatic structural units are, independently of one another, identical or different, and
The admixture for SCM admixture high content concrete whose mass average molecular weight Mw of the polycondensate containing the said structural unit (I), (II) and (III) is the range of 3,000-50,000. 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 bonded to the three aromatic structural units of the structural unit (I), the structural unit (II) and the structural unit (IV), wherein the aromatic structural units are independent of each other Identical or different, and
The blend according to claim 1, wherein the weight 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. Agent.   The admixture according to claim 1, further comprising a retention aid.   The blend 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-adsorbable monomer. Agent.   The copolymer according to claim 3, wherein the retention aid is a copolymer formed by polymerizing a hydrolyzable monomer and an ethylenically unsaturated monomer containing a polyoxyalkylene group without containing a cement-adsorbable monomer. Admixture of.   The admixture according to any one of claims 1 to 5, further comprising a retarder selected from the group consisting of oxycarboxylic acids, oxycarboxylates, sugars and sugar alcohols. The composition according to any one of claims 1 to 6, which is applied to SCM admixture high content concrete containing blast furnace slag as an SCM admixture, and having a substitution ratio of said blast furnace slag to cement of more than 60%. Admixture. The SCM admixture high content concrete according to any one of claims 1 to 6, which contains silica fume as the SCM admixture, and which has a substitution ratio of said silica fume to cement exceeding 20%. Admixture. The SCM admixture high content concrete according to any one of claims 1 to 6, which contains fly ash as the SCM admixture, and is applied to the SCM admixture high content concrete in which the replacement ratio of the fly ash to cement is more than 20%. Admixture.   An admixture-containing composition comprising the admixture according to any one of claims 1 to 9 and C-S-H-based fine particles as a curing accelerator.   A cement composition comprising the admixture according to any one of the preceding claims.