JP2007326766A - Dispersant for hydraulic composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dispersant for a hydraulic composition which exerts excellent effects to the dispersibility, fluidity and fluidity retention property of the hydraulic compositions having a wide range of composition and material. <P>SOLUTION: The dispersant for the hydraulic compositions includes a polymer which is prepared by copolymerizing a specific monomer 1 of an ethylenic unsaturated carboxylic derivative and the like having a polyoxyalkylene group, a phosphoric acid monoester monomer 2, a phosphoric acid diester monomer 3, and an unsaturated carboxylic acid monomer 4 under a pH condition of not greater than 7, and has a ratio (Mw/Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 1.0-2.6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dispersant for a hydraulic composition and a hydraulic composition.

  Among the admixtures for hydraulic compositions, there is one called a high-performance water reducing agent having a large fluidity-imparting effect. Typical examples thereof include naphthalene sulfonic acid formaldehyde condensate salt (naphthalene type), melamine sulfonic acid formaldehyde condensate salt (melamine type), polycarboxylic acid type having a polyoxyalkylene chain, and the like. However, in general, when highly reduced concrete is prepared using a cement dispersant, there is a problem that slump loss is remarkable and workability such as filling property and workability is lowered.

  Therefore, conventionally, it has been proposed to use a water-soluble vinyl copolymer having a slump loss prevention performance as a cement dispersant.

In addition, concrete prepared using hydraulic powder such as medium-heated Portland cement and low-heat Portland cement and other high belite cement (cement with increased C ₂ S cement content) and slag cement containing blast furnace slag. In this case, the slump flow may decrease with time because the amount of cement dispersant used to obtain the required fluidity decreases.

  Furthermore, because high-strength concrete is prepared by mixing with a compound composition having a small water / hydraulic powder ratio (hereinafter referred to as water / cement ratio) compared to concrete of ordinary strength (general strength), There are problems such as high viscosity of concrete.

  This viscosity increase problem has not been sufficiently solved even with a polycarboxylic acid-based water reducing agent, and an additive having a higher concrete viscosity reducing effect is desired.

  From such a background, Patent Document 1 discloses the viscosity of high-strength concrete containing a vinyl copolymer containing a high-chain-length oxyalkylene group, a short-chain-length oxyalkylene group and a specific monomer as essential components. An admixture excellent in reduction and suppression of setting delay is disclosed.

  Further, Patent Document 2 discloses a monoester or monoether having a polyalkylene glycol chain in order to obtain a cement dispersant capable of exhibiting excellent flow characteristics, high dispersion effect and quick setting regardless of the mixing ratio of water. And a polymer of a monomer having an unsaturated bond and a phosphate group.

Moreover, patent document 3 is disclosing the polymer obtained from three types of monomers, and its hydraulic composition use.
JP-A-11-157897 JP 2000-327386 A International Publication No. 2006/006732 Pamphlet

  In a hydraulic composition such as concrete in an ultra-high strength region, the polymers of Patent Document 1 and Patent Document 2 are desired to further improve fluidity and viscosity reduction. Also, from the viewpoint of expanding the versatility of materials such as cement and aggregate, it is desirable that a polymer having a structure other than Patent Document 1 can be used.

Recently, a number of cement types have been used for hydraulic compositions such as concrete. Not only cements with different mineral compositions, but also high belite cement and blast furnace slag such as medium heat Portland cement and low heat Portland cement are used. Special cements such as blended slag cement are also used. In addition, the water / hydraulic powder ratio in concrete also covers a wide range, in particular, a so-called high-strength region concrete having a water / hydraulic powder ratio of 20 to 35% by weight and a water / hydraulic powder ratio exceeding this range. The required properties are different from those of so-called general concrete. Furthermore, considering from the manufacturer who manufactures the hydraulic composition, properly using the dispersant depending on the composition and material is not only complicated in production but also a tank of various dispersants (one type in the premises of those skilled in the art). 2 to 10 m ³ per tank) must be installed, and from this background, the dispersant used in the hydraulic composition can be used for such a wide range of composition and material hydraulic compositions. It is desired that the effect required for each is expressed evenly.

  In response to such a demand, it is conceivable to construct a dispersant or an admixture for a hydraulic composition by combining a plurality of components in consideration of the characteristics of the additive component. At that time, by combining a component excellent in initial dispersion performance (initial dispersion component), a component excellent in dispersibility retention performance (dispersion retention component), and a component that brings about an appropriate curing delay (delay component), etc. Although it is considered that the effects of imparting dispersibility, fluidity, and fluidity retention can be obtained in a well-balanced manner, the admixtures of Patent Documents 1 and 2 are said to exhibit sufficient effects for use from such a viewpoint. hard.

  The subject of this invention is providing the dispersing agent for hydraulic compositions which expresses the effect excellent in the dispersibility, the fluidity | liquidity, and the fluid holding | maintenance property with respect to the hydraulic composition of a wide composition and material.

  The present invention relates to a monomer 1 represented by the following general formula (1) (hereinafter referred to as monomer 1) and a monomer 2 represented by the following general formula (2) (hereinafter referred to as monomer 2). ), A monomer 3 represented by the following general formula (3) (hereinafter referred to as monomer 3), and a monomer 4 represented by the following general formula (4) (hereinafter referred to as monomer 4). Is a dispersing agent for a hydraulic composition containing a polymer obtained by copolymerization at a pH of 7 or less, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the polymer is Mw / It is related with the dispersing agent for hydraulic compositions whose Mn is 1.0-2.6.

[In the formula, R ¹ and R ² are each a hydrogen atom or a methyl group, R ³ is a hydrogen atom, or — (CH ₂ ) _q (CO) _p O (AO) _r R ⁴ , and AO has 2 to 4 carbon atoms. An oxyalkylene group or an oxystyrene group, p is a number of 0 or 1, q is a number of 0 to 2, p and q are not simultaneously 0, r is an average added mole number of AO, a number of 3 to 300, R ⁴ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. ]

[Wherein R ¹¹ is a hydrogen atom or a methyl group, R ¹² is an alkylene group having 2 to 12 carbon atoms, m1 is a number of 1 to 30, M ³ and M ⁴ are a hydrogen atom, an alkali metal or an alkaline earth metal, respectively. Represents. ]

[Wherein R ¹³ and R ¹⁵ are each a hydrogen atom or a methyl group, R ¹⁴ and R ¹⁶ are each an alkylene group having 2 to 12 carbon atoms, m2 and m3 are each a number of 1 to 30 and M ⁵ is Represents a hydrogen atom, an alkali metal or an alkaline earth metal. ]

Wherein, R ¹⁷ to R ¹⁹ are each a hydrogen atom, a methyl group or ^{_{(CH 2) s COOM 7,}} (CH 2) s COOM 7 is COOM ⁶ or another (CH _{2) s} COOM ⁷ anhydride In this case, M ⁶ and M ⁷ of those groups are not present. s represents the number of 0-2. M ⁶ and M ⁷ each represent a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an alkyl ammonium group, a substituted alkyl ammonium group, an alkyl group, a hydroxyalkyl group, or an alkenyl group. ]

  The present invention further includes a monomer 1 represented by the general formula (1), a monomer 2 represented by the general formula (2), and a monomer represented by the general formula (3). 3 and a monomer 4 represented by the above general formula (4) are provided in the presence of a chain transfer agent at a pH of 7 or less.

  The present invention also provides a hydraulic composition comprising the above-described dispersant for a hydraulic composition of the present invention, a hydraulic powder, and water, wherein the hydraulic powder comprises ordinary Portland cement, moderately heated Portland cement. And a hydraulic composition that is at least one selected from the group consisting of a low heat Portland cement and a blast furnace slag cement.

The present invention also provides a hydraulic composition comprising the above-described dispersant for a hydraulic composition of the present invention, hydraulic powder, fine aggregate, coarse aggregate, and water, wherein the water / water The present invention relates to a hydraulic composition having a hard powder ratio of 20 to 60% by weight and a unit water amount of 120 to 185 kg / m ³ .

  ADVANTAGE OF THE INVENTION According to this invention, the dispersing agent for hydraulic compositions which expresses the effect excellent in the dispersibility, fluidity | liquidity, and fluid holding | maintenance with respect to the hydraulic composition of a wide composition and a material is provided.

  The polymer according to the present invention includes the monomer 1 represented by the general formula (1), the monomer 2 represented by the general formula (2), and the general formula (3). It is a polymer obtained by copolymerizing the monomer 3 represented by the above and the monomer 4 represented by the general formula (4) described above as essential components at a pH of 7 or less. The carboxyl group of the general formula (4) and the phosphoric acid group of the general formulas (2) and (3) introduced into the polymer function as an adsorbing group to the hydraulic powder, and the general formula (1) It is presumed that the oxyalkylene group functions as a repulsive group between the hydraulic powder particles.

  About the adsorption | suction characteristic to the hydraulic powder of a carboxyl group and a phosphoric acid group, although unknown, it estimates as follows.

In general, a cement dispersant is blended with an “initial dispersion component” that exhibits dispersibility immediately after kneading and a “dispersion-holding component” that exhibits dispersibility after some time has elapsed after kneading. Conventional polycarboxylic acid-based dispersants are selectively used by changing the blending ratio of the initial dispersion component and the dispersion holding component depending on the composition (water cement ratio) and material (cement type). In other words, ordinary Portland cement and high-strength concrete, which require a relatively large amount of addition, can be dealt with by increasing the amount of the initial dispersion component, and slag cement, high belite cement (C ₂ S) with a relatively small amount of addition. In general strength concrete, the dispersion retention property is satisfied by increasing the dispersion retention component. Thus, it is necessary to use different cement dispersants because the amount of addition varies depending on the composition and material.

Considering the variation factor of the amount of addition in terms of cement type, the chemical components of the cement are calcinated by tricalcium silicate (C ₃ S), dicalcium silicate (C ₂ S), tricalcium aluminate (C ₃ A), Compounds such as tetracalcium iron aluminate (C ₄ AF) are included. The initial dispersion component of the polycarboxylic acid-based dispersant tends to specifically adsorb to C ₃ A that is relatively contained in ordinary Portland cement. Therefore, when a polycarboxylic acid-based dispersant having a relatively low C ₃ A cement such as slag cement or high belite cement and having an optimized mixing ratio between the initial dispersion component and the dispersion retention component is used in ordinary Portland cement, The initial dispersion component of the carboxylic acid-based dispersant specifically adsorbs to C ₃ A, which has a severe initial hydration reaction, and a considerable amount of the initial dispersion component disappears at a stage of several minutes of initial hydration. The initial fluidity cannot be obtained, and the fluidity tends to develop over time due to the dispersion-holding component (if the added amount is increased and the initial fluidity is manifested), the dispersion-holding component The amount of fluid becomes excessive and the fluidity develops over time). On the other hand, when the mixing ratio of the initial dispersion component and the dispersion retention component is optimized with ordinary Portland cement, the amount of addition is decreased with slag cement or high belite cement, and the fluid retention effect cannot be obtained.

On the other hand, phosphate groups do not show specific adsorptivity to cement minerals compared to carboxyl groups, but their water solubility is low, so they may be affected by the salt concentration associated with cement hydration. . In other words, ordinary Portland cement containing a large amount of C ₃ A, which has a remarkable initial hydration reaction, tends to increase the salt concentration in water and increase the adsorption rate. In the case of slag cement and high belite cement, where C ₃ A decreases. The adsorption rate tends to be slow.

  Therefore, it is inferred that by containing and optimizing carboxyl groups and phosphate groups having different adsorption characteristics, the effects required for each of the hydraulic compositions of a wide range of compositions and materials can be expressed evenly. .

[Monomer 1]
In monomer 1, R ¹ and R ² in general formula (1) are each a hydrogen atom or a methyl group. R ³ is a hydrogen atom or — (CH ₂ ) _q (CO) _p O (AO) _r R ⁴ , preferably a hydrogen atom. Examples of alkenyl in the general formula (1) include an allyl group and a methallyl group. When p is 0, AO forms an ether bond with (CH ₂ ) _q, and when p is 1, it forms an ester bond. q is 0 to 2, preferably 0 or 1, and more preferably 0. p and q are not 0 at the same time. AO is an oxyalkylene group having 2 to 4 carbon atoms or an oxystyrene group, and AO is preferably an oxyalkylene group having 2 to 4 carbon atoms, more preferably an ethyleneoxy group (hereinafter referred to as EO group), and an EO group. Is 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more. r is the average added mole number of AO, is a number of 3 to 300, and is 3 to 300, preferably 4 to 120 in terms of the dispersibility of the polymer in the hydraulic composition and the effect of reducing the viscosity. More preferably, it is 4-80, More preferably, it is 4-50, Especially preferably, it is 4-30. Moreover, AO is different in an average of r repeating units, and random addition, block addition, or a mixture thereof may be included. For example, AO can contain a propyleneoxy group etc. besides EO group.

R ⁴ is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, preferably 1 to 12, more preferably 1 to 4, and further preferably 1 or 2, and particularly preferably a methyl group.

  Monomer 1 includes a half-terminated alkyl-capped polyalkylene glycol such as methoxypolyethylene glycol, methoxypolypropylene glycol, methoxypolybutylene glycol, methoxypolystyrene glycol, ethoxypolyethylenepolypropyleneglycol, (meth) acrylic acid, maleic acid (half ) Esterified products, etherified products with (meth) allyl alcohol, and (meth) acrylic acid, maleic acid, and (meth) allyl alcohol adducts having 2 to 4 carbon atoms are preferably used. In addition, (meth) acrylic acid means acrylic acid and / or methacrylic acid, and (meth) allyl means allyl and / or methallyl (the same applies hereinafter).

  More preferred is an esterified product of alkoxy, particularly methoxypolyethylene glycol and (meth) acrylic acid. Specific examples include ω-methoxypolyoxyalkylene methacrylate and ω-methoxypolyoxyalkylene acrylate, and ω-methoxypolyoxyalkylene methacrylate is more preferable.

  Monomer 1 used for production of the polymer of the present invention can be obtained, for example, by esterification of alkoxypolyalkylene glycol and (meth) acrylic acid. Unreacted (meth) acrylic acid of the esterified product can be used as the monomer 4. From the viewpoint of making the required addition amount constant when used in a concrete dispersant by reducing the variation in the amount of the monomer 4, the unreacted (meth) acrylic acid of the esterified product is a single amount in terms of acid type. It is preferably 5% by weight or less, more preferably 3% by weight or less, still more preferably 1.5% by weight or less, and still more preferably 1% by weight or less with respect to the body 1. Examples of a method for reducing the amount of (meth) acrylic acid remaining during the production of the monomer 1 include topping, steaming, and solvent extraction.

[Monomer 2]
In the monomer (2), R ¹¹ is a hydrogen atom or a methyl group, and R ¹² is an alkylene group having 2 to 12 carbon atoms. m1 is a number from 1 to 30, and M ³ and M ⁴ are each a hydrogen atom, an alkali metal, or an alkaline earth metal. 1-20 are preferable, as for m1 in General formula (2), 1-10 are more preferable, and 1-5 are especially preferable.

  Specific examples include phosphoric acid monoesters of organic hydroxy compounds. Specific examples include polyalkylene glycol mono (meth) acrylate acid phosphates. For example, phosphoric acid mono-[(2-hydroxyethyl) methacrylic acid] ester, phosphoric acid mono-[(2-hydroxyethyl) acrylic acid ester] and the like can be mentioned. Among these, phosphoric acid mono-[(2-hydroxyethyl) methacrylic acid] ester is preferable from the viewpoint of ease of production and product quality stability. Further, alkali metal salts, alkaline earth metal salts, ammonium salts, alkylammonium salts and the like of these compounds may be used.

[Monomer 3]
In the monomer 3, in the general formula (3), R ¹³ and R ¹⁵ are each a hydrogen atom or a methyl group, and R ¹⁴ and R ¹⁶ are each an alkylene group having 2 to 12 carbon atoms. m2, m3 is a number of each 1 to 30, M ⁵ represents a hydrogen atom, an alkali metal or alkaline earth metal. M2 and m3 in the general formula (3) are each preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 5.

  Specific examples include phosphoric acid diesters of organic hydroxy compounds. Specific examples include polyalkylene glycol di (meth) acrylate acid phosphoric acid diester. Examples include phosphoric acid di-[(2-hydroxyethyl) methacrylic acid] ester, phosphoric acid di-[(2-hydroxyethyl) acrylic acid] ester, and the like. Among these, di-[(2-hydroxyethyl) methacrylic acid] ester phosphate is preferable from the viewpoint of ease of production and quality stability of the product. Further, alkali metal salts, alkaline earth metal salts, ammonium salts, alkylammonium salts and the like of these compounds may be used.

  Monomers 2 and 3 can be used as a mixed monomer including monomer 2 and monomer 3. Further, as the monomer 2 and the monomer 3, a phosphate ester obtained by reacting an organic hydroxy compound represented by the general formula (5) with a phosphorylating agent may be used.

  The mixed monomer including the monomer 2 and the monomer 3 is obtained as a reaction product by reacting, for example, the organic hydroxy compound represented by the general formula (5) with a phosphorylating agent at a predetermined charge ratio. It can also be manufactured.

[Wherein, R ²⁰ represents a hydrogen atom or a methyl group, R ²¹ represents an alkylene group having 2 to 12 carbon atoms, and m4 represents a number of 1 to 30. ]

  1-20 are preferable, as for m4 in General formula (5), 1-10 are more preferable, and 1-5 are especially preferable.

  Examples of the phosphorylating agent include orthophosphoric acid, phosphorus pentoxide (anhydrous phosphoric acid), polyphosphoric acid, phosphorus oxychloride and the like, and orthophosphoric acid and phosphorus pentoxide are preferable. These may be used alone or in combination of two or more. The amount of the phosphorylating agent in the reaction of the organic hydroxy compound and the phosphorylating agent can be appropriately determined according to the target phosphate ester composition.

  For example, when a mixture of phosphoric acid mono-[(2-hydroxyethyl) methacrylic acid] ester and phosphoric acid di-[(2-hydroxyethyl) methacrylic acid] ester is used, a known technique (for example, special No. 57-180618).

  As the mixed monomer including the monomer 2 and the monomer 3, a commercial product including a monoester and a diester can be used. For example, Phosmer M, Phosmer PE, Phosmer P (Unichemical) , JAMP514, JAMP514P, JMP100 (all Johoku Chemical), light ester P-1M, light acrylate P-1A (all Kyoeisha Chemical), MR200 (Daihachi Chemical), Kayamar (Nippon Kayaku), Ethyleneglycol methacrylate phosphate (Aldrich) Reagent).

  Monomers 2 and 3 are phosphoric acid esters of monomers having unsaturated bonds and hydroxyl groups, and the above-mentioned commercially available products and reaction products include monoester (monomer 2) and diester ( It has been confirmed that it contains compounds other than monomer 3). These other compounds are considered to be a mixture of polymerizable and non-polymerizable compounds, but in the present invention, such a mixture (mixed monomer) can be used as it is.

[Monomer 4]
In the monomer 4, in the general formula (4), R ^{17 to} R ¹⁹ are each a hydrogen atom, a methyl group, or (CH ₂ ) _s COOM ⁷ , and (CH ₂ ) _s COOM ⁷ is COOM ⁶ or other An anhydride may be formed with (CH ₂ ) _s COOM ⁷ . In that case, M ⁶ and M ⁷ of those groups do not exist. s represents the number of 0-2. R ¹⁷ is preferably a hydrogen atom, and R ¹⁸ is preferably a methyl group. R ¹⁹ is preferably a hydrogen atom or (CH ₂ ) _s COOM ⁷ .

M ⁶ and M ⁷ are each a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an alkyl ammonium group, a substituted alkyl ammonium group, an alkyl group, a hydroxyalkyl group, or an alkenyl group. M ⁶ and M ⁷ are each preferably a hydrogen atom or an alkali metal.

  Specifically, monocarboxylic acid monomers such as (meth) acrylic acid and crotonic acid, dicarboxylic acid monomers such as maleic acid, itaconic acid and fumaric acid, or anhydrides or salts thereof (for example, alkalis) Metal salt, alkaline earth metal salt, ammonium salt, mono-, di-, trialkyl (carbon number 2 to 8) ammonium salt optionally substituted with hydroxyl group) or ester, preferably (meth) acrylic acid, Maleic acid, maleic anhydride, more preferably (meth) acrylic acid or an alkali metal salt thereof. In addition, (meth) acrylic acid means acrylic acid and / or methacrylic acid (hereinafter the same).

  The polymer according to the present invention includes a phosphate group-carboxyl group complex weight obtained by copolymerizing monomer 1, monomer 2, monomer 3, and monomer 4 at a pH of 7 or less. It is a coalescence. It is also preferable to use a mixed monomer containing monomer 2 and monomer 3.

  Preferable monomers 1, 2, 3, and 4 are as described above, and the above-mentioned commercially available products and reaction products can also be used.

  In the copolymerization of the monomers, the proportion of the monomer 1 is preferably 60 to 98% by weight, more preferably 70 to 95% by weight, and even more preferably 70 to 90% by weight in the total monomers used for the polymerization. . The total proportion of monomer 2 and monomer 3 is preferably 1 to 39% by weight, more preferably 2 to 28% by weight, and even more preferably 5 to 25% by weight. The proportion of monomer 4 is preferably 1 to 39% by weight, more preferably 1 to 28% by weight, and even more preferably 1 to 15% by weight.

  The molar ratio of monomer 1 to monomers 2, 3 and monomer 4 is (monomer 1) / (monomer 2 + monomer 3 + monomer 4) = 5/95. ~ 95/5, more preferably 10/90 to 90/10. The molar ratio of the monomers 2, 3 and the monomer 4 is (monomer 2 + monomer 3) / monomer 4 = 5/95 to 95/5, more preferably 10/90 to 90/10. Is preferred. In the present invention, for monomer 2, monomer 3, and monomer 4, the weight ratio, weight%, mole ratio, and mole% are calculated based on the acid type compound (hereinafter the same) ).

  In the production of the polymer, the ratio of the monomer 3 in all monomers used in the reaction is 1 to 15% by weight, further 1 to 12% by weight, particularly 2 to 10% by weight, and further 3 to 6% by weight. Is preferred.

  Monomer 3 imparts a branched structure to the resulting polymer. Since the polymer according to the present invention has an appropriate branched structure, the area occupied on the hydraulic powder can be reduced when adsorbed to the hydraulic powder. Therefore, a larger number of polymers can be adsorbed to the hydraulic powder, and when the value of Mw / Mn described later is in a specific range and the molecular weight distribution is narrow, a larger number of polymers are water. It can be adsorbed on hard powder. As a result, it is considered that excellent dispersibility, fluidity and fluidity are exhibited.

  The molar ratio of monomer 2 to monomer 3 is preferably monomer 2 / monomer 3 = 99/1 to 4/96, more preferably 99/1 to 5/95.

  From the viewpoint of suppressing gelation, the monomer solution containing the monomer 3 is preferably used for the reaction at a pH of 7 or less.

  Hereinafter, more preferable production conditions will be described from the viewpoints of gelation suppression, adjustment of a suitable molecular weight, and performance design of a dispersant for hydraulic composition. From such a viewpoint, at the time of copolymerization, 4 mol% or more, further 6 mol% or more, particularly 8 mol% or more of the chain transfer agent is added to the total number of moles of the monomers 1, 2, 3 and 4. It is preferable to use it. The upper limit of the amount of chain transfer agent used is preferably 100 mol% or less, more preferably 60 mol% or less, and still more preferably 30 mol%, based on the total number of moles of monomers 1, 2, 3 and 4. In the following, it is particularly preferably 15 mol% or less. Therefore, the range of the amount of chain transfer agent used is preferably 4 to 60 mol%, more preferably 6 to 30 mol%, and more preferably 8 to 15 with respect to the total number of moles of monomers 1, 2, 3 and 4. More preferred is mol%.

  The reaction rate of the monomers 2, 3 and 4 is preferably 60% or more, more preferably 70% or more, more preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. Can be selected from this point of view. Here, the reaction rates of the monomers 2, 3 and 4 are calculated by the following formula.

In addition, the ratio (mol%) of the ethylenically unsaturated bonds of the monomers 2, 3 and 4 in the phosphorus-containing compound in the reaction system at the start and end of the reaction is the measurement result of ¹ H-NMR described below. Can be calculated based on
[ ¹ H-NMR conditions]
A polymer dissolved in water and dried under reduced pressure is dissolved in deuterated methanol at a concentration of 3 to 4% by weight, and ¹ H-NMR is measured. The proportion of ethylenically unsaturated bonds is measured by an integral value of 5.5 to 6.2 ppm. In addition, the measurement of ¹ H-NMR uses “Mercury 400 NMR” manufactured by Varian, the number of data points is 42052, the measurement range is 6410.3 Hz, the pulse width is 4.5 μs, the pulse waiting time is 10 S, and the measurement temperature is 25.0 ° C. Perform under conditions.

  In the production of the polymer, in addition to the monomers 1, 2, 3, and 4, other monomers that can be copolymerized may be used. Examples of other copolymerizable monomers include allyl sulfonic acid, methallyl sulfonic acid, any of these alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts. In addition, acrylic monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and the like, and any one or more of alkali metal salts, alkalis Anhydrous compounds such as earth metal salts, ammonium salts, amine salts, methyl esters, ethyl esters and maleic anhydride may also be used. Furthermore, (meth) acrylamide, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2- (meth) acrylamide-2-metasulfonic acid, 2- (meth) acrylamide-2-ethanesulfonic acid, Examples include 2- (meth) acrylamide-2-propanesulfonic acid, styrene, styrenesulfonic acid and the like. The total proportion of monomers 1, 2, and 3 in all monomers is preferably 30 to 100 mol%, more preferably 50 to 100 mol%, particularly preferably 75 to 100 mol%, and more than 95 mol% to 100 Mol%, more preferably 97 to 100 mol%, and particularly preferably 100 mol%.

  In the production of the polymer, the monomers are preferably copolymerized in the presence of a predetermined amount of chain transfer agent. Moreover, you may use the other monomer, polymerization initiator, etc. which can be copolymerized.

  The reaction temperature of the monomers 1, 2, 3 and 4 is preferably 40 to 100 ° C., more preferably 60 to 90 ° C., and the reaction pressure is 101.3 to 111.5 kPa (1 to 1.1 atm) in gauge pressure, 101.3-106.4 kPa (1-1.05 atm) is preferable.

  The pH of the reaction system can be adjusted with an inorganic acid (phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid, etc.), NaOH, KOH, triethanolamine, or the like, if necessary.

  Here, the monomer solution containing the monomer 3 is preferably a water-containing system (that is, the solvent contains water) for pH measurement, but in the case of a non-aqueous system, a necessary amount of water is added. May be measured. In view of uniformity of the monomer solution, prevention of gelation, and suppression of performance deterioration, the pH is preferably 7 or less, more preferably 0.1 to 6, further preferably 0.2 to 4.5, and further preferably 0. 5-3 are preferable. Monomer 1 is also preferably used as a monomer solution having a pH of 7 or less. This pH is at 20 ° C.

  In the present invention, the pH at 20 ° C. of the reaction solution collected during the reaction (from the start of the reaction to the end of the reaction) is defined as the pH during the reaction. It is preferable to start the reaction under conditions that clearly show that the pH during the reaction is 7 or less (monomer ratio, solvent, other components, etc.).

  When the reaction system is non-aqueous, it can be measured by adding an amount of water capable of measuring pH to the reaction system.

In the method for producing a polymer, the monomers 1, 2, 3 and 4 can be reacted under the conditions exemplified in the following (1) and (2). The pH during the reaction is considered to be 7 or less.
(1) A monomer solution having a pH of 7 or less containing all of the monomers 1, 2, 3, and 4 is used for the copolymerization reaction of the monomers 1, 2, 3, and 4.
(2) The copolymerization reaction of monomers 1, 2, 3 and 4 is started at pH 7 or less. That is, the reaction is started after the reaction system containing the monomers 1, 2, 3 and 4 is brought to pH 7 or lower.

[Chain transfer agent]
The chain transfer agent has a function of causing a chain transfer reaction in radical polymerization (a reaction in which a growing polymer radical reacts with another molecule to move a radical active site). It is a substance to be added.

  Examples of chain transfer agents include thiol chain transfer agents and halogenated hydrocarbon chain transfer agents, and thiol chain transfer agents are preferred.

As the thiol chain transfer agent, those having a —SH group are preferable, and in particular, the general formula HS—R—Eg (wherein R represents a hydrocarbon-derived group having 1 to 4 carbon atoms, and E is − OH, —COOM, —COOR ′ or —SO ₃ M group, M represents a hydrogen atom, monovalent metal, divalent metal, ammonium group or organic amine group, and R ′ represents an alkyl having 1 to 10 carbon atoms. In which g represents an integer of 1 to 2, for example, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, Examples include octyl thioglycolate, octyl 3-mercaptopropionate, and the like from the viewpoint of chain transfer effect in a copolymerization reaction including monomers 1 to 3. Mercaptoethanol are preferable, more preferably mercaptopropionic acid. These 1 type (s) or 2 or more types can be used.

  Examples of the halogenated hydrocarbon chain transfer agent include carbon tetrachloride and carbon tetrabromide.

  Examples of other chain transfer agents include α-methylstyrene dimer, terpinolene, α-terpinene, γ-terpinene, dipentene, 2-aminopropan-1-ol and the like. A chain transfer agent can use 1 type (s) or 2 or more types.

[Polymerization initiator]
In the method for producing the polymer, it is preferable to use a polymerization initiator, and in particular, the polymerization initiator is 5 mol% or more, further 7 to 50 mol based on the total number of moles of the monomers 1, 2, 3 and 4. %, Particularly 10 to 30 mol% is preferred.

  Examples of aqueous polymerization initiators include ammonium persulfate salt or alkali metal salt, hydrogen peroxide, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis (2-methylpropionamide) dihydrate, etc. These water-soluble azo compounds can be used. In addition, an accelerator such as sodium bisulfite and an amine compound can be used in combination with the polymerization initiator.

[solvent]
The production of the polymer can be carried out by a solution polymerization method, and the solvent used at that time is water or water containing water and methyl alcohol, ethyl alcohol, isopropyl alcohol acetone, methyl ethyl ketone, or the like. Examples of the solvent are solvents. In view of handling and reaction equipment, water is preferred. In particular, when an aqueous solvent is used, the pH of the monomer solution containing the monomer 3 is preferably 7 or less, and further 0.1 to 6, particularly 0.2 to 4 is used for the reaction. Is preferable from the viewpoint of uniformity (handleability) of the monomer mixture, monomer reaction rate, and crosslinking by hydrolysis of the pyro compound of the phosphoric acid compound.

  An example of the manufacturing method of a polymer is shown. A predetermined amount of water is charged into a reaction vessel, the atmosphere is replaced with an inert gas such as nitrogen, and the temperature is raised. A monomer 1, a monomer 2, a monomer 3, a monomer 4 and a chain transfer agent mixed and dissolved in water and a polymerization initiator dissolved in water were prepared in advance. Add dropwise to reaction vessel over ~ 5 hours. At that time, each monomer, chain transfer agent and polymerization initiator may be dropped separately, or a mixed solution of monomers can be charged in a reaction vessel in advance and only the polymerization initiator can be dropped. is there. That is, the chain transfer agent, the polymerization initiator, and other additives may be added as an additive solution separately from the monomer solution, or may be added to the monomer solution after being added. From the viewpoint of stability, it is preferable to supply the reaction system as an additive solution separately from the monomer solution. In any case, the pH of the solution containing the monomer 3 is preferably 7 or less. Further, the copolymerization reaction is carried out with an acid agent or the like while maintaining the pH at 7 or less, and preferably aging is carried out for a predetermined time. The polymerization initiator may be added dropwise at the same time as the monomer, or may be added in portions, but it is preferable to add in portions in terms of reducing unreacted monomers. For example, in the total amount of the polymerization initiator to be finally used, 1/2 to 2/3 polymerization initiator is added simultaneously with the monomer, and the remainder is aged for 1 to 2 hours after the completion of the monomer dropping, It is preferable to add. If necessary, the polymer according to the present invention is obtained by further neutralization with an alkali agent (such as sodium hydroxide) after completion of aging. This production example is suitable as a method for producing the polymer A according to the present invention.

  The total amount of the monomers 1, 2, 3, and 4 in the reaction system and the other copolymerizable monomers is preferably 5 to 80% by weight, more preferably 10 to 65% by weight, and 20 to 50% by weight. Particularly preferred.

  The polymer preferably has a weight average molecular weight (Mw) of 10,000 to 100,000. This polymer A has a Mw of 10,000 or more, preferably 12,000 or more, more preferably 13,000 or more, more preferably 14,000 or more, from the viewpoint of the expression of the dispersion effect or the viscosity reduction effect. Particularly preferably, it is 15,000 or more, and it is 100,000 or less, preferably 95,000 or less, more preferably from the viewpoints of high molecular weight by crosslinking, suppression of gelation, and performance in terms of dispersion effect and viscosity reduction effect. 90,000 or less, more preferably 85,000 or less, particularly preferably 80,000 or less, and from the viewpoints of both, preferably 12,000 to 950,000, more preferably 13,000 to 90,000, More preferably, it is 14,000-85,000, Most preferably, it is 15,000-80,000. Even more preferably, it is 20,000 to 60,000, and even more preferably 30,000 to 50,000. It is preferable to have Mw in this range.

  The polymer according to the present invention has Mw / Mn of 1.0 to 2.6. Here, Mn is a number average molecular weight. Here, the value of Mw / Mn is the degree of dispersion. The closer the value is to 1, the closer the molecular weight distribution is to the monodispersion, and the farther from 1 (the larger) the wider the molecular weight distribution.

  The Mw / Mn of the polymer is preferably 1.0 to 2.4, more preferably 1.0 to 2.2, and more preferably 1.0 to 2.0, from the viewpoint of the dispersion effect and the viscosity reduction effect. Especially preferably, it is 1.0-1.8.

  The polymer according to the present invention having the Mw / Mn value as described above is a polymer having a branched structure based on the diester structure of the monomer 3, but has a great feature that the molecular weight distribution is very narrow. Such a polymer of the present invention can be suitably produced, for example, by adjusting the amount of the chain transfer agent. Increasing the amount of chain transfer agent decreases the value of Mw / Mn.

Mw and Mn of the polymer are those measured by gel permeation chromatography (GPC) method under the following conditions. In addition, Mw and Mn of the polymer in this invention shall be calculated based on the peak of this polymer.
[GPC conditions]
Column: G4000PWXL + G2500PWXL (Tosoh)
Eluent: 0.2M phosphate buffer / CH ₃ CN = 9/1
Flow rate: 1.0mL / min
Column temperature: 40 ° C
Detection: RI
Sample size: 0.2mg / mL
Reference material: Polyethylene glycol equivalent

  Further, in the chart pattern showing the molecular weight distribution obtained by the GPC method under the above conditions, the area having a molecular weight of 100,000 or more is 5% or less of the total area of the chart, so that dispersibility (required addition amount reduction) It is more preferable in terms of the viscosity reducing effect.

<Dispersant for hydraulic composition>
The dispersant for a hydraulic composition of the present invention is used in a ratio of 0.1 to 5 parts by weight, and further 0.2 to 3 parts by weight in solid content with respect to 100 parts by weight of hydraulic powder, particularly cement. It is preferable in terms of fluidity expression and viscosity reduction effect.

  The dispersant for hydraulic composition of the present invention can also contain other additives (materials). For example, resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, alkylbenzene sulfonic acid (salt), alkane sulfonate, polyoxyalkylene alkyl (phenyl) ether, polyoxyalkylene alkyl (phenyl) ether sulfate (salt) ), Polyoxyalkylene alkyl (phenyl) ether phosphate (salt), protein material, AE agent such as alkenyl succinic acid, α-olefin sulfonate; foaming agent; thickener; silica sand; AE water reducing agent; calcium chloride, Soluble calcium salts such as calcium nitrite, calcium nitrate, calcium bromide and calcium iodide, chlorides such as iron chloride and magnesium chloride, sulfate, potassium hydroxide, sodium hydroxide, carbonate, thiosulfate, formic acid (Salt), a Fastening agents or accelerators such as canolamine; foaming agents; waterproofing agents such as resin acids (salts), fatty acid esters, oils and fats, silicones, paraffins, asphalts, waxes; blast furnace slag; fluidizing agents; dimethylpolysiloxanes, polyalkylenes Antifoaming agents such as glycol fatty acid esters, mineral oils, fats and oils, oxyalkylenes, alcohols and amides; antifoaming agents; fly ash; melamine sulfonic acid formalin condensates, aminosulfonic acids, polymaleic acid, etc. High-performance water reducing agent; Silica fume; Anticorrosive agent such as nitrite, phosphate, zinc oxide; EO adduct of polyacrylic acid amide, polyethylene glycol, oleyl alcohol or reaction product of this with vinylcyclohexene diepoxide, etc. Water-soluble polymers such as synthetic systems; Polymers such as alkyl (meth) acrylates Marujon is mentioned. The concentration of the polymer in the total solid content of the concrete dispersant of the present invention is 20 to 100% by weight, more preferably 20 to 80% by weight, further 25 to 70% by weight, and particularly 30 to 70% by weight. preferable.

  In addition, the polymer according to the present invention may be used alone, but it is preferable to use the “dispersion holding component” (hereinafter referred to as a holding agent) in combination from the viewpoint of further improving the holding property. In that case, the polymer / retaining agent according to the present invention is preferably 20/80 to 90/10, more preferably 25/75 to 80/20. Although it does not limit as a retention agent, The polymer obtained by copolymerizing the monomer 1, the monomer 2, and the monomer 3 by pH 7 or less is not included although the monomer 4 is not included.

  The holding agent is an agent that adsorbs to the hydraulic powder over time and develops the fluidity of the hydraulic composition. By using the polymer according to the present invention and the holding agent in combination, the fluidity of the hydraulic composition is maintained even if time passes after kneading.

  If the polymer according to the present invention is used in combination with a retaining agent, the hydraulic composition will have fluidity even after time has elapsed after kneading. It is useful in cases where the transport time is long, for example, 30 minutes or longer.

  Conversely, in the case of producing a concrete product on the same site, even when producing fresh concrete, the transport time of fresh concrete to the placement site is short, for example, less than 30 minutes, in the case of the polymer according to the present invention. It is preferable to use it alone.

  Further, as described above, as a reason for not being limited as a retaining agent, the polymer according to the present invention is adsorbed on the hydraulic powder during the initial hydration reaction immediately after kneading the hydraulic powder and water. Since the effect of the present invention is exhibited, the retaining agent that adsorbs over time and develops fluidity is used for adsorption during the initial hydration reaction immediately after kneading the hydraulic powder of the polymer according to the present invention and water. It is assumed that it does not affect.

  From the viewpoint of adsorbing to the hydraulic powder over time and expressing the fluidity of the hydraulic composition, it is obtained by copolymerizing monomer 1, monomer 2, and monomer 3 described above at a pH of 7 or less. The composition of the phosphate ester polymer is such that the monomer 1 is preferably 60 to 90 mol%, more preferably 60 to 85 mol%, still more preferably 65 to 80 in the monomers used for the polymerization of the polymer. It is a polymer using mol%, and the total of monomers 2 and 3 is preferably 10 to 40 mol%, more preferably 15 to 40 mol%, and still more preferably 20 to 35 mol%. is there. As the ratio between the monomers 2 and 3, the same molar ratio as that of the polymer according to the present invention can be used.

  Furthermore, the combined use of a polycarboxylic acid type dispersant is also effective. As an example of a polycarboxylic acid-based dispersant, a polymer obtained by copolymerizing monomer 1 and monomer 4 can be cited. From the viewpoint of expressing fluidity, the monomer 1 is preferably 20 to 70 mol%, more preferably 25 to 60 mol%, still more preferably 30 to 50 mol% in the monomer used for the polymerization of the polymer. The monomer 4 is preferably a polymer using 30 to 80 mol%, more preferably 40 to 75 mol%, still more preferably 50 to 70 mol%. Among these, from the viewpoint of suppressing the increase in the viscosity of the hydraulic composition over time, a retention agent made of a phosphate ester polymer is preferable.

<Hydraulic composition>
The hydraulic composition that is the subject of the present invention is a hydraulic composition containing hydraulic powder and water, and the hydraulic powder is a powder having physical properties that are cured by a hydration reaction. , Cement, plaster and the like. Preferred are ordinary Portland cement, Belite cement, medium heat cement, early strong cement, super early strong cement, sulfate resistant cement, etc., and blast furnace slag, fly ash, silica fume, stone powder (calcium carbonate powder), etc. May be added. In addition, the hydraulic composition finally obtained by adding sand, sand and gravel as aggregates (fine aggregate, coarse aggregate) to these powders is generally called mortar, concrete, etc., respectively. Yes. The dispersant and hydraulic composition of the present invention are not only for ready-mixed concrete and concrete vibration products, but also for self-leveling, for refractories, for plaster, for gypsum slurry, for lightweight or heavy concrete, for AE, for repair, and pre-packed. It is useful in any field of various concrete, such as for use in the field, for use in tromy, for grout, for ground improvement, and for cold use.

  The hydraulic composition, particularly concrete, which is the subject of the present invention, has a water / hydraulic powder ratio [weight percentage of water and hydraulic powder in slurry (wt%), usually abbreviated as W / P, When the powder is cement, it is abbreviated as W / C. It can be 65% by weight or less, further 10 to 60% by weight, further 12 to 57% by weight, further 15 to 55% by weight, especially 20 to 55% by weight. In particular, the effect of the dispersant of the present invention is remarkably exhibited in various cements in a high strength blend of 20 to 35% by weight.

The hydraulic composition of the present invention preferably has a water amount per 1 m ^{3 of the} composition, that is, a unit water amount of 120 to 185 kg / m ³ from the viewpoint of suppression of cement amount (economic efficiency). In particular, when the W / P is 20 to 60% by weight, the unit water amount is preferably within this range.

Production Example (R-1)
A glass reaction vessel (four-necked flask) with a stirrer was charged with 367 g of water, purged with nitrogen while stirring, and heated to 80 ° C. in a nitrogen atmosphere. 426 g of ω-methoxypolyethylene glycol monomethacrylate (average added mole number of ethylene oxide 23) (effective part 60.8 wt%, moisture 35 wt%), methacrylic acid 64.2 g and 3-mercaptopropionic acid 3.2 g were mixed. Then, 85% phosphoric acid was added to the solution and adjusted to pH 2.0, and 11.4 g of ammonium persulfate dissolved in 64 g of water were added dropwise over 1.5 hours. After aging for 1 hour, 5.7 g of ammonium persulfate dissolved in 32 g of water was added dropwise over 30 minutes, and then aging was carried out at the same temperature (80 ° C.) for 1.5 hours. After completion of aging, a 32% aqueous sodium hydroxide solution was added dropwise to neutralize to pH 6.0 to obtain a polymer R-1 having a weight average molecular weight of 48,000. (Reaction rate 100%)

  Kind of monomer, mol%, weight%, ratio of monomer 3 in all monomers, pH at the time of reaction, weight average molecular weight of obtained polymer and ratio of weight average molecular weight to number average molecular weight (Mw / Mn) is shown in Table 1.

Production Example (R-2)
A glass reaction vessel (four-necked flask) equipped with a stirrer was charged with 352 g of water, purged with nitrogen while stirring, and heated to 80 ° C. in a nitrogen atmosphere. ω-methoxypolyethyleneglycol monomethacrylate (average added mole number of ethylene oxide 23) 397 g (effective part 60.8% by weight, moisture 35% by weight), phosphoric acid mono-[(2-hydroxyethyl) methacrylic acid] ester and phosphorus A mixture of 123.4 g of phosphoric acid ester (A) which is a mixture of acid di-[(2-hydroxyethyl) methacrylic acid] ester and 6.1 g of 3-mercaptopropionic acid, and 11.9 g of ammonium persulfate in water Two of those dissolved in 67 g were added dropwise over 1.5 hours. After aging for 1 hour, 2.6 g of ammonium persulfate dissolved in 15 g of water was added dropwise over 30 minutes, and then aging was carried out at the same temperature (80 ° C.) for 1.5 hours. After completion of aging, a 32% aqueous sodium hydroxide solution was added dropwise to neutralize to pH 6.0 to obtain a polymer R-2 having a weight average molecular weight of 36000. (Reaction rate 99%)

The phosphoric acid ester (A) used in this production example was charged with 200 g of 2-hydroxyethyl methacrylate and 36.0 g of 85% phosphoric acid (H ₃ PO ₄ ) in a reaction vessel. After gradually adding 89.1 g of phosphoric anhydride (P ₂ O ₅ ) while cooling so that the temperature does not exceed 60 ° C., the reaction temperature is set to 80 ° C., the reaction is performed for 6 hours, and the mixture is cooled. It is what was done. This phosphate esterified product (A) was also used in some of the following production examples.

Production Example (A-1)
A glass reaction vessel with a stirrer (four-necked flask) was charged with 346 g of water, purged with nitrogen while stirring, and heated to 80 ° C. in a nitrogen atmosphere. 391 g of ω-methoxypolyethyleneglycol monomethacrylate (average added mole number of ethylene oxide 23) (effective part 60.8% by weight, moisture 35% by weight), phosphoric acid mono-[(2-hydroxyethyl) methacrylic acid] ester and phosphorus A mixture of 64.9 g of phosphoric acid ester (A), 43.2 g of methacrylic acid and 4.9 g of 3-mercaptopropionic acid, which is a mixture of acid di-[(2-hydroxyethyl) methacrylic acid] ester, Two of 14.6 g of ammonium sulfate dissolved in 83 g of water were added dropwise over 1.5 hours. After aging for 1 hour, 4.2 g of ammonium persulfate dissolved in 24 g of water was added dropwise over 30 minutes, and then aging was performed at the same temperature (80 ° C.) for 1.5 hours. After completion of aging, a 32% aqueous sodium hydroxide solution was added dropwise to neutralize to pH 6.0 to obtain a polymer A-1 having a weight average molecular weight of 42,000. (Reaction rate 100%)

Production Example (A-2)
Polymer A-2 was produced in the same manner as Polymer A-1, except that the monomer ratios shown in Table 1 were used.

  Table 1 summarizes the monomer charge ratios of the above production examples.

The symbols in the table are as follows, and the number in () is the EO average added mole number (the same applies hereinafter).
MEPEG-E: ω-methoxypolyethylene glycol monomethacrylate MAA: methacrylic acid HEMA-MPE: 2-hydroxyethyl methacrylate monophosphate ester HEMA-DPE: 2-hydroxyethyl methacrylate diphosphate ester Mw: weight average molecular weight

Production examples (B-1 and B-2)
Polymers B-1 and B-2 were produced in the same manner as the polymer R-2 except that the monomer ratios shown in Table 2 were used. Table 2 summarizes the monomer charge ratios of the production examples.

<Test example> [Concrete test]
(1) Cement dispersant The polymers shown in Tables 1 and 2 were used as cement dispersants in the weight ratios shown in Tables 4-6. Using this cement dispersant, tests on concrete having the composition shown in Table 3 were performed as follows. The results are shown in Tables 4-6. S-1 is saccharose (retarding agent).

(2) Concrete mix The concrete mix is as shown in Table 3.

The materials used in Table 3 are as follows.
W: Ion-exchanged water C1: Ordinary Portland cement (1: 1 mixture of ordinary Portland cement manufactured by Taiheiyo Cement Co., Ltd. and ordinary Portland cement manufactured by Sumitomo Osaka Cement Co., Ltd.)
C2: Low heat Portland cement (Low heat Portland cement manufactured by Taiheiyo Cement Co., Ltd.)
S1: Fine aggregate, land sand from Kodama-gun, Saitama Prefecture (density: 2.62 g / cm ³ )
S2: Fine aggregate, crushed sand from Aso-gun, Tochigi Prefecture (density: 2.62 g / cm ³ )
S3: Fine aggregate, sand from Kimitsu, Chiba Prefecture (density: 2.61 g / cm ³ )
G: Coarse aggregate, crushed stone 2005 from Aso-gun, Tochigi Prefecture (density: 2.70 g / cm ³ )

(3) Preparation of concrete Using a forced biaxial mixer manufactured by IHI as a mixer to be used, concrete was prepared in a concrete volume of 30 liters, a stirring time of 10 seconds for kneading, and 90 seconds after adding kneaded water. At that time, in the case of Formulation I and Formulation II, the addition amount of the dispersant (polymer blend) was adjusted so that the slump flow value became 600 to 680 mm after 30 minutes of preparation. In the case of Formulation III, the amount of cement dispersant added was adjusted so that the slump was 20 to 22 cm immediately after preparation.

  In addition, the slump flow value in the combination I and the combination II is an average value of the maximum value of the slump flow value and the slump flow value measured in the direction perpendicular to the length of a half of the line segment that gives the maximum value. . In addition, the concrete slump flow test was similarly performed according to JIS A 1150, except that each layer was uniformly projected with a five-thrust bar (maximum size of coarse aggregate (G) 20 mm, concrete temperature 20 to 22 ° C., How to pack samples: Pack in 3 layers). Moreover, the slump value in the blend III was performed according to the slump test (JIS A 1101). The amount of concrete air (JIS A 1128) is determined by adding an antifoaming agent. In the case of Formulation I and Formulation II, the amount of entrained air is 3.0 vol% or less. Was adjusted to 4.0 to 5.0% by volume.

(4) Concrete evaluation About the concrete which added the dispersing agent prepared above, the fluidity (slump flow or slump) immediately after agitation and the fluidity (slump flow) after being left for 15 minutes or 30 minutes and then kneaded with a scoop. Or slump). The results are shown in Tables 4-6. Table 4 shows Formulation I (ordinary Portland cement, W / C = 30 wt%), Table 5 shows Formulation II (low heat Portland cement, W / C = 30 wt%), and Table 6 shows Formulation III (ordinary Portland cement cement, (W / C = 45% by weight). In blends I and II, slump flow was measured for high-strength concrete, and in blend III, slump was measured for general-strength concrete.

  In Table 4, the addition amount is the weight percent of the dispersant (in terms of solid content) with respect to the cement weight (the same applies hereinafter).

  Test Examples 1 and 6 are dispersants using a polycarboxylic acid polymer, Test Examples 3 and 8, Test Examples 4 and 9, and Test Examples 5, 10 and 11 are dispersions using the polymer according to the present invention. It is a test with an agent. In all the test examples, a phosphate polymer was used in combination.

  In the test examples using the polymer according to the present invention, the change in fluidity is small immediately after and after 15 minutes or 30 minutes in any formulation, and has a wide composition (water cement ratio) and material (cement type). It can be seen that the required effects are fully expressed for each hydraulic composition. On the other hand, in the case of blending I (Table 4) in which ordinary Portland cement is W / C = 30% by weight, the immediately following slump flow value is small in the combined system of polycarboxylic acid polymer (Test Example 1) and after 15 minutes. You can see that it tends to grow. In addition, in Formulation II (Table 5) with W / C = 30% by weight with low heat Portland cement, it can be seen that in Test Example 7, the slump flow value immediately after is small and tends to increase after 15 minutes.

  In addition, the polymer R-2 according to the present invention and A-2 not using the monomer 4 have substantially the same weight average molecular weight and Mw / Mn values. The value of the difference in slump flow after 15 minutes is not significantly different between Test Example 4 and Test Example 2 using each polymer in Formulation I, but in Test Example 9 and Test Example 7 of Formulation II, the value after 15 minutes The difference in slump flow is very different. From this result, it can be seen that the polymer according to the present invention is highly versatile for hydraulic powders having different compositions and materials.

Claims (9)

Monomer 1 represented by the following general formula (1), monomer 2 represented by the following general formula (2), monomer 3 represented by the following general formula (3), and the following general formula A dispersant for a hydraulic composition containing a polymer obtained by copolymerizing the monomer 4 represented by the formula (4) at a pH of 7 or less, wherein the weight average molecular weight (Mw) of the polymer is A dispersant for a hydraulic composition having a number average molecular weight (Mn) ratio Mw / Mn of 1.0 to 2.6.

[In the formula, R ¹ and R ² are each a hydrogen atom or a methyl group, R ³ is a hydrogen atom, or — (CH ₂ ) _q (CO) _p O (AO) _r R ⁴ , and AO has 2 to 4 carbon atoms. An oxyalkylene group or an oxystyrene group, p is a number of 0 or 1, q is a number of 0 to 2, p and q are not simultaneously 0, r is an average added mole number of AO, a number of 3 to 300, R ⁴ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. ]

[Wherein R ¹¹ is a hydrogen atom or a methyl group, R ¹² is an alkylene group having 2 to 12 carbon atoms, m1 is a number of 1 to 30, M ³ and M ⁴ are a hydrogen atom, an alkali metal or an alkaline earth metal, respectively. Represents. ]

[Wherein R ¹³ and R ¹⁵ are each a hydrogen atom or a methyl group, R ¹⁴ and R ¹⁶ are each an alkylene group having 2 to 12 carbon atoms, m2 and m3 are each a number of 1 to 30 and M ⁵ is Represents a hydrogen atom, an alkali metal or an alkaline earth metal. ]

Wherein, R ¹⁷ to R ¹⁹ are each a hydrogen atom, a methyl group or ^{_{(CH 2) s COOM 7,}} (CH 2) s COOM 7 is COOM ⁶ or another (CH _{2) s} COOM ⁷ anhydride In this case, M ⁶ and M ⁷ of those groups are not present. s represents the number of 0-2. M ⁶ and M ⁷ each represent a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an alkyl ammonium group, a substituted alkyl ammonium group, an alkyl group, a hydroxyalkyl group, or an alkenyl group. ] At the time of copolymerization, the proportion of monomer 1 is 60 to 98% by weight, and the total proportion of monomer 2 and monomer 3 is 1 to 39% by weight, based on the total monomer constituting the polymer. The dispersant for a hydraulic composition according to claim 1, wherein the ratio of the body 4 is 1 to 39% by weight. The dispersant for a hydraulic composition according to claim 1 or 2, wherein the polymer has a weight average molecular weight (Mw) of 15,000 to 80,000. Furthermore, the dispersing agent for hydraulic hydraulic compositions in any one of Claims 1-3 containing a retention agent. A hydraulic composition containing the dispersant for hydraulic composition according to any one of claims 1 to 4, a hydraulic powder, and water, wherein the hydraulic powder is a normal Portland cement, a medium-heated Portland cement. A hydraulic composition that is at least one selected from the group consisting of a cement, a low heat Portland cement and a blast furnace slag cement. A hydraulic composition comprising the dispersant for hydraulic composition according to any one of claims 1 to 4, a hydraulic powder, a fine aggregate, a coarse aggregate, and water, wherein water / water A hydraulic composition having a hard powder ratio of 10 to 60% by weight and a unit water amount of 120 to 185 kg / m ³ . Monomer 1 represented by the following general formula (1), monomer 2 represented by the following general formula (2), monomer 3 represented by the following general formula (3), and the following general formula A method for producing a phosphate ester polymer, which comprises copolymerizing the monomer 4 represented by the formula (4) with a pH of 7 or less in the presence of a chain transfer agent.

[In the formula, R ¹ and R ² are each a hydrogen atom or a methyl group, R ³ is a hydrogen atom, or — (CH ₂ ) _q (CO) _p O (AO) _r R ⁴ , and AO has 2 to 4 carbon atoms. An oxyalkylene group or an oxystyrene group, p is a number of 0 or 1, q is a number of 0 to 2, p and q are not simultaneously 0, r is an average added mole number of AO, a number of 3 to 300, R ⁴ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. ]

[Wherein R ¹¹ is a hydrogen atom or a methyl group, R ¹² is an alkylene group having 2 to 12 carbon atoms, m1 is a number of 1 to 30, M ³ and M ⁴ are a hydrogen atom, an alkali metal or an alkaline earth metal, respectively. Represents. ]

[Wherein R ¹³ and R ¹⁵ are each a hydrogen atom or a methyl group, R ¹⁴ and R ¹⁶ are each an alkylene group having 2 to 12 carbon atoms, m2 and m3 are each a number of 1 to 30 and M ⁵ is Represents a hydrogen atom, an alkali metal or an alkaline earth metal. ]

Wherein, R ¹⁷ to R ¹⁹ are each a hydrogen atom, a methyl group or ^{_{(CH 2) s COOM 7,}} (CH 2) s COOM 7 is COOM ⁶ or another (CH _{2) s} COOM ⁷ anhydride In this case, M ⁶ and M ⁷ of those groups are not present. s represents the number of 0-2. M ⁶ and M ⁷ each represent a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an alkyl ammonium group, a substituted alkyl ammonium group, an alkyl group, a hydroxyalkyl group, or an alkenyl group. ] The method for producing a phosphate ester polymer according to claim 7, wherein a ratio Mw / Mn of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polymer is 1.0 to 2.6. The method for producing a phosphate ester polymer according to claim 7 or 8, wherein the chain transfer agent is a thiol chain transfer agent.