JP2009096672A - Dispersant for hydraulic composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dispersant for a hydraulic composition which exhibits stable initial flowability and flow retentivity not depending on the kind of a hydraulic powder. <P>SOLUTION: The dispersant for a hydraulic composition includes a copolymer obtained by polymerizing a specific monomer 1 expressed by general formula (1), a specific monomer 2 expressed by general formula (2), and a specific monomer 3 expressed by general formula (3), wherein in the component monomers of the copolymer, the ratios of the monomer 1, the monomer 2, and the monomer 3 respectively are in specific ranges. In formula (1), R<SP>1</SP>-R<SP>3</SP>respectively represent a hydrogen atom or a methyl group, AO represents a 2-4C oxyalkylene group, n is the number of average addition moles of AO, and represents the number of 5-20, R<SP>4</SP>is a hydrogen atom or a 1-4C alkyl group, q is an integer of 0-2, and p represents 0 or 1. In formula (2), R<SP>5</SP>is a 1-4C hydrocarbon group which may contain a hetero atom. In formula (3), R<SP>6</SP>-R<SP>8</SP>respectively are a hydrogen atom, a methyl group or (CH<SB>2</SB>)<SB>S</SB>COOM<SP>2</SP>, (CH<SB>2</SB>)<SB>S</SB>COOM<SP>2</SP>may form an anhydride with COOM<SP>1</SP>or other (CH<SB>2</SB>)<SB>S</SB>COOM<SP>2</SP>, in that case, M<SP>1</SP>and M<SP>2</SP>of those groups do not exist. s represents an integer of 0-2. M<SP>1</SP>and M<SP>2</SP>respectively 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. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  In order to impart fluidity to hydraulic compositions such as concrete, admixtures such as naphthalene-based, melamine-based, aminosulfonic acid-based, and polycarboxylic acid-based materials (high performance water reducing agents) are used. For admixtures such as water reducing agents, various performances are required such as imparting fluidity to hydraulic compositions, fluidity retention (flow retention), prevention of cure delay, etc. Improvements are also proposed from this perspective.

In Patent Document 1, a concrete admixture comprising a copolymer having a specific ethylenically unsaturated monomer unit and an ethylenically unsaturated carboxylic acid ester unit as a structural unit can be used in combination with a high-performance water reducing agent. It is disclosed. Patent Document 2 discloses a cement admixture comprising a terpolymer of an ethylene monomer having a polyoxyalkylene group, an unsaturated organic acid monomer, and a monomer that can be hydrolyzed in an alkaline aqueous solution. Patent Document 3 discloses a copolymer of a polyalkylene glycol mono (meth) acrylate ester monomer, a mono (meth) acrylate ester monomer, and a carboxylic acid monomer having an unsaturated bond It is disclosed that a cement admixture made of is excellent in improving slump retention and workability.
JP-A-10-81549 JP-A-2005-330129 JP 2003-286057 A

  Patent Documents 1 to 3 disclose a technique for maintaining the fluidity and viscosity of a hydraulic composition, but depending on the type of cement, the initial fluidity and fluidity retention performance fluctuate. Expected performance may not be obtained in quantity. Regardless of the type of hydraulic powder (cement, etc.) used in the hydraulic composition, a dispersant for a hydraulic composition that exhibits the same fluidity maintaining effect and viscosity maintaining effect with the same addition amount is desired. .

  An object of the present invention is to provide a dispersant for a hydraulic composition that exhibits stable initial fluidity and fluidity retention regardless of the type of hydraulic powder.

  Patent Documents 1 and 2 aim to achieve both initial fluidity and fluidity, but the fluidity and fluidity tend to vary sensitively depending on the cement type. This is probably because a relatively large average addition mole number n of oxyalkylene groups was introduced into the structure.

  Moreover, in patent document 3, although the initial fluidity | liquidity is shown, the fluid retainability is inadequate. This is presumably because the introduction amount of the carboxylic acid unit having a large contribution to the initial fluidity is large and the ester unit having a large contribution to the fluidity retention is small. Also, the initial fluidity tends to vary sensitively depending on the cement type.

  Different types of hydraulic powders have different mineral compositions. As a result, when the hydraulic powder and water are kneaded, the fluidity varies because the hydration rate and the concentration of sulfate ions eluted in the aqueous phase vary depending on the type of hydraulic powder. . This is because the polycarboxylic acid polymer has a three-dimensional structure that changes depending on the salt concentration in the aqueous phase and the dispersion performance changes, and the polymer adsorbed on the surface of the hydraulic powder is taken into the hydrate. It is considered that the flowability and the holding property differ depending on the kind of hydraulic powder due to the difference in speed.

  Conventionally, if the AO average addition mole number of the polycarboxylic acid polymer is not large to some extent, there is no contribution of fluidity due to steric repulsion, and the increase in adsorbing groups due to hydrolysis is considered to have a small fluidity retention effect over time (Patent Document 2, paragraph 0010). However, the present inventors have found that in polycarboxylic acid polymers, the average number of added moles of oxyalkylene groups (steric repulsion units) for reducing the change in dispersibility depending on the salt concentration of the aqueous phase and the adsorption thereof. By adjusting the balance between the specific unit (hydrolysis unit) and the initial adsorbing unit (carboxylic acid unit) that can become an adsorbing group over time, the initial fluidity and fluid retention are excellent, and water A highly versatile dispersant for hard powder types has been completed.

That is, the present invention polymerizes the monomer 1 represented by the general formula (1), the monomer 2 represented by the general formula (2), and the monomer 3 represented by the general formula (3). A dispersant for a hydraulic composition containing a copolymer obtained by:
Among the constituent monomers of the copolymer, the ratio of monomer 1 is 25 to 85% by weight, the ratio of monomer 2 is 10 to 70% by weight, and the ratio of monomer 3 is 5 to 5%. It is related with the dispersing agent for hydraulic compositions which is 20 weight%.

[Wherein, R ^{1 to} R ³ each represent a hydrogen atom or a methyl group, AO represents an oxyalkylene group having 2 to 4 carbon atoms, n represents an average added mole number of AO, and a number of 5 to 20 R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, q represents an integer of 0 to 2, and p represents 0 or 1. ]

[Wherein R ⁵ is a hydrocarbon group which may contain a hetero atom having 1 to 4 carbon atoms. ]

Wherein, R ⁶ to R ⁸ are each a hydrogen atom, a methyl group or ^{_{(CH 2) s COOM 2,}} (CH 2) s COOM 2 is COOM ¹ or another (CH _{²⁾ s} COOM ₂ and anhydrous In this case, M ¹ and M ² of those groups are not present. s represents the integer of 0-2. M ¹ and M ² 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. ]

  ADVANTAGE OF THE INVENTION According to this invention, the dispersing agent for hydraulic compositions excellent in the initial fluidity | liquidity and fluid holding | maintenance property is provided irrespective of the kind of hydraulic powder.

<Monomer 1>
The monomer 1 is an unsaturated polyalkylene glycol monomer such as a polyalkylene glycol monoester monomer and a polyalkylene glycol alkyl ether monomer, and in the monomer 1, the general formula (1) AO in it represents an oxyalkylene group having 2 to 4 carbon atoms and includes at least one selected from the group consisting of an oxyethylene group, an oxypropylene group, and an oxybutylene group, and among them, an oxyethylene group is preferable. n is the average number of added moles of AO and represents a number of 5 to 20, preferably 6 to 20, more preferably 7 to 19, and still more preferably 8 from the viewpoint of versatility of initial dispersibility and fluidity retention. -18, and even more preferably 9-17. When n exceeds 20, fluctuations in initial fluidity and fluidity due to the type of hydraulic powder increase. R ⁴ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and is preferably a hydrogen atom or a methyl group, more preferably a methyl group, from the viewpoint of fluidity retention.

  As monomer 1, methoxypolyethylene glycol, methoxypolyethylenepolypropylene glycol, ethoxypolyethyleneglycol, ethoxypolyethylenepolypropyleneglycol, propoxypolyethyleneglycol, propoxypolyethylenepolypropyleneglycol, etc., one-end alkyl-capped polyalkyleneglycol and acrylic acid or methacrylic acid Esterified products, addition products of ethylene oxide or propylene oxide to acrylic acid or methacrylic acid, etherification products of the above-mentioned one-end alkyl-blocked polyalkylene glycol and (meth) alkenyl alcohol, and alkylene having 2 to 4 carbon atoms to alkenyl alcohol An oxide adduct or the like can be used. Specifically, ω-methoxypolyethylene glycol monomethacrylate, ω-methoxypolyethyleneglycol monoacrylate, polyoxyethylene monoallyl ether, ω-methoxypolyethyleneglycol monoallyl ether, poly (3-methyl-3-buten-1-ol) Examples include oxyethylene monoallyl ether. From the viewpoint of fluidity retention, esterified products of one-end alkyl-blocked polyalkylene glycol and acrylic acid or methacrylic acid are preferred, preferably ω-methoxypolyethylene glycol monomethacrylate, ω-methoxypolyethyleneglycol monoacrylate, ω- Methoxy polyethylene glycol monomethacrylate is more preferred.

<Monomer 2>
Monomer 2 is an acrylic ester monomer, structurally, can be considered as an ester of an alcohol compound represented by acrylic acid and R ⁵ -OH, R ⁵ is 1 to 4 carbon atoms, Preferably it is a hydrocarbon group which may contain 2 to 3 heteroatoms. Examples of the hetero atom include an oxygen atom and a nitrogen atom.

In the present invention, it is preferable that a specific monomer among the monomers represented by the general formula (2) is used as at least a part of the monomer 2. That is, as at least part of the monomer 2, the general formula (2) R ⁵ in a logP value of R ⁵ -OH corresponding to R ⁵ in the general formula (2), the molecular weight of the monomer 2 It is preferable to use a compound (hereinafter referred to as monomer 2-1) in which Mw is [log P value of R ⁵ —OH / molecular weight Mw of monomer 2] <− 0.009. Further, in addition to the monomer 2-1, that is, in the monomer 2, a compound having [R ⁵ —OH logP value / monomer 2 molecular weight Mw] ≧ −0.009 is obtained. That's it. Examples of R ⁵ —OH satisfying such a relationship include ethylene glycol (log P value: −1.369), glycerin (log P value: −1.538), and the like. The proportion of the monomer 2-1 in the monomer 2 is preferably 30 mol% or more in the monomer 2 from the viewpoints of versatility with respect to the type of hydraulic powder, and also flow retention and viscosity. More preferably, mol% or more is more preferable, 70 mol% or more is more preferable, 90 mol% or more is further more preferable, and substantially 100 mol% is still more preferable.

  As the monomer 2-1, 2-hydroxyethyl acrylate is preferable from the viewpoint of maintaining fluidity. Examples of the monomer 2-2 include methyl acrylate, hydroxybutyl acrylate, methoxyethyl acrylate, and the like. Two or more types of monomers may be used for each of the monomer 2-1 and the monomer 2-2.

  In the copolymer serving as the dispersant of the present invention, by introducing the monomer 2, the fluidity of the hydraulic composition can be maintained from the initial stage of addition to the hydraulic composition over time. This is because, since monomer 2 has an acrylic ester structure before addition to the hydraulic composition, hydrolysis of the ester bond progresses over time after addition, resulting in a carboxylic acid type or a carboxylate type. Thus, it is presumed that the copolymer gradually adsorbs on the surface of the hydraulic powder and maintains the dispersion of the hydraulic powder to offset the increase in viscosity due to the hydration of the hydraulic powder. Further, it is speculated that the change in hydrolysis rate due to factors such as the ionic strength of the hydraulic composition exhibits the same fluidity retention regardless of the type of hydraulic powder. Even if it has a similar structure, the effect of the monomer 2 cannot be obtained with an ester of methacrylic acid or its alkylene oxide adduct, which is harder to hydrolyze than acrylic acid.

In addition, as for the monomer 2-1, the molecular weight of the monomer 2-1 and the log P of the compound represented by R ⁵ —OH composed of the substituent R ⁵ and the hydroxyl group OH of the monomer 2-1 ( It was found that there is a correlation between the water / octanol distribution coefficient (hereinafter logP refers to logP of the compound unless otherwise specified) and the speed of expression of the dispersibility of the hydraulic powder. That is, the hydrolyzability varies depending on the ester substituent of acrylic acid, and hydrolyzation has steps of nucleophilicity of water molecule to ester and elimination of alcohol. It was thought that ease contributed. The hydrolysis rate decreases as the molecular weight of the monomer increases (the steric hindrance increases), and the hydrolysis rate increases as the hydrophilicity (log P) value of the hydrolysis group of the alcohol compound constituting the ester decreases. Therefore, logP was normalized by the molecular weight Mw of the acrylate ester, and used as an index of the efficiency of the introduced group (carboxyl group production rate). Therefore, the smaller the value of logP / molecular weight Mw, the greater the hydrolyzability of monomer 2-1. In the present invention, this value is −0.009 or less, more preferably −0.010 or less, and even more preferably −0.011 or less. logP can be obtained as a ClogP value using the software of CS Chem Draw Ultra (Ver. 8.0) (distributed Cambridge Software). For example, the software is executed on a personal computer running Windows (registered trademark) XP. it can.

[Monomer 3]
Monomer 3 are the compounds of formula (3), R ⁶ ~R ⁸ are each a hydrogen atom, a methyl group or ^{_{(CH 2) s COOM 2,}} (CH 2) s COOM 2 is COOM ¹ or other (CH ₂ ) _s COOM ² and an anhydride may be formed. In that case, M ¹ and M ² of those groups do not exist. s represents the integer of 0-2. R ¹ is preferably a hydrogen atom, and R ² is preferably a methyl group. R ³ is preferably a hydrogen atom or (CH ₂ ) _s COOM ⁷ .

M ¹ and M ² are each a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroxyalkyl group, or an alkenyl group. M ¹ and M ² 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).

  In the copolymer serving as the dispersant of the present invention, by introducing the monomer 3 together with the monomer 2, a predetermined adsorption amount can be initially shown and initial fluidity can be shown. At that time, since the quantitative relationship between the content (% by weight) of the monomer 3 and the content (% by weight) of the monomer 2 affects the fluidity retention, it is preferably a specific relationship described later.

<Copolymer>
The copolymer of the present invention has a monomer 1 ratio of 25 to 85% by weight and a monomer 2 ratio of 10 to 70% by weight. The ratio of the monomer 3 is 5 to 20% by weight. Moreover, it is preferable that monomer 2 / monomer 3 (weight ratio) exceeds 1 in the ratio in the constituent monomer of the copolymer. Furthermore, the total ratio of monomer 1, monomer 2 and monomer 3 in the constituent monomers of the copolymer is preferably 90% by weight or more. This ratio may be the ratio when the monomer is charged. If the ratio of the monomer 1 is less than 25% by weight, the initial fluidity and fluidity retention are lowered, and if it exceeds 85% by weight, the adsorptivity is lowered, and therefore the initial fluidity and fluidity retention are lowered. When the ratio of the monomer 2 is less than 10% by weight or the ratio of the monomer 3 exceeds 20% by weight, the fluidity retention is lowered.

  The ratio of the monomer 1 is preferably 35 to 70% by weight, more preferably 40 to 70, from the viewpoint of improving the initial fluidity and fluidity retention and suppressing the influence of the kind of hydraulic powder. Further, the ratio of the monomer 2 is preferably 15 to 60% by weight, more preferably 17 to 50% in the total monomers used in the polymerization of the copolymer from the viewpoint of initial fluidity and fluidity retention. % By weight, more preferably 20-40% by weight. Further, the ratio of the monomer 3 is preferably 5 to 15% by weight, more preferably 8 to 15% in the total monomers used in the polymerization of the copolymer from the viewpoint of initial fluidity and fluidity retention. % By weight, more preferably 10 to 15% by weight.

  In the copolymer of the present invention, two or more monomers 1 having different n can be used in combination. In that case, the ratio of the monomer 1 is n (the same applies hereinafter) for the average value (depending on the molar fraction) of the monomers 1 having different n.

  The total of monomer 1, monomer 2 and monomer 3 in all the constituent monomers of the copolymer is the total amount used in the polymerization of the copolymer from the viewpoint of initial fluidity and fluidity retention. In the polymer, 90% by weight or more is preferable, more preferably 95% by weight or more, and still more preferably 98% by weight or more.

  Further, the total ratio of the monomer 2 and the monomer 3 in the constituent monomers is preferably 15 in the total monomers used in the polymerization of the copolymer from the viewpoint of initial fluidity and fluidity retention. It is -75 weight%, More preferably, it is 22-72 weight%, More preferably, it is 30-65 weight%.

  Further, from the viewpoint of little influence by the kind of the fluid retaining property and the hydraulic powder, the weight ratio of the monomer 2 to the monomer 3 in the constituent monomers is more than 1 for the monomer 2 / monomer 3. Preferably, it is 1.2 or more, more preferably 1.5 or more.

  The weight ratio of monomer 1, monomer 2 and monomer 3 (monomer 1 / monomer 2 / monomer 3) is 25 to 85/10 to 70/5 from the viewpoint of fluidity retention. -20, preferably 28-78 / 15-60 / 5-15, more preferably 35-75 / 17-50 / 8-15, still more preferably 40-70 / 20-40 / 10-15.

  Moreover, the copolymer of this invention may copolymerize the monomer 4 copolymerizable with the monomers 1-3. The monomer 4 is preferably 5% by weight or less, more preferably 2.5% by weight or less, and still more preferably from all the constituent monomers of the copolymer from the viewpoint of suppressing initial fluidity and fluid retention performance. Is 1.0% by weight or less.

  As the monomer 4, phosphoric acid di-[(2-hydroxyethyl) methacrylic acid] ester, phosphoric acid di-[(2-hydroxyethyl) acrylic acid] ester, phosphoric acid mono (2-hydroxyethyl) methacrylic acid Ester, mono (2-hydroxyethyl) acrylate ester, polyalkylene glycol mono (meth) acrylate acid phosphate ester, and any one or more alkali metal salts, alkali Acid anhydrides such as earth metal salts, ammonium salts, amine salts and maleic anhydride may be used.

  Other monomers 4 include allyl sulfonic acid, methallyl sulfonic acid, any of these alkali metal salts, alkaline earth metal salts, ammonium salts, or amine salts, (meth) acrylamide, N-methyl (meth) Acrylamide, N, N-dimethyl (meth) acrylamide, 2- (meth) acrylamide-2-metasulfonic acid, 2- (meth) acrylamide-2-ethanesulfonic acid, 2- (meth) acrylamide-2-propanesulfonic acid, Examples thereof include monomers having acid groups of strong acids such as styrene and styrenesulfonic acid or neutralizing groups thereof. These monomers may be copolymerized for adjusting the molecular weight of the copolymer, for example. The acid groups of these strong acids exist as stable salts in the hydraulic composition and do not function as adsorbing groups to hydraulic powders such as cement.

  The copolymer in the present invention can be produced by a known method. Examples thereof include solution polymerization methods described in JP-A-62-1119147 and JP-A-62-78137. That is, it is produced by polymerizing the monomer 1, the monomer 2 and the monomer 3 in combination in the above ratio in an appropriate solvent. That is, in all monomers used for copolymerization, the ratio of monomer 1 is 25 to 85% by weight, the ratio of monomer 2 is 10 to 70% by weight, and the ratio of monomer 3 is Polymerize as 5-20% by weight.

  Examples of the solvent used in the solution polymerization method include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, benzene, toluene, xylene, cyclohexane, n-hexane, ethyl acetate, acetone, and methyl ethyl ketone. In consideration of handling and reaction equipment, water and methyl alcohol, ethyl alcohol, and isopropyl alcohol are preferable.

  As an aqueous polymerization initiator, persulfuric acid ammonium salt or alkali metal salt or hydrogen peroxide, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis (2-methylpropionamide) Water-soluble azo compounds such as dihydrate are used. For solution polymerization using a non-aqueous solvent, peroxides such as benzoyl peroxide and lauroyl peroxide, aliphatic azo compounds such as azobisisobutyronitrile, and the like are used.

  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 'represents or -SO ₃ M group, M represents a hydrogen atom, a monovalent metal, a divalent metal, an ammonium group or an organic amine group, R' is 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.

  An example of the manufacturing method of the copolymer which concerns on this invention 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. Prepare monomer 1, monomer 2, monomer 3, chain transfer agent mixed and dissolved in water, and polymerization initiator dissolved in water, and take 0.5 to 5 hours. Drip into the reaction vessel. 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. Further, aging is preferably performed 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 copolymer according to the present invention is obtained by further neutralizing with an alkali agent (such as sodium hydroxide) after completion of aging.

  Further, the copolymer according to the present invention is obtained by introducing a liquid A containing monomer 1, a liquid B containing monomer 2 and a liquid C containing monomer 3 into a reaction system. It can also be used for the polymerization reaction, and liquid A, liquid B, and liquid C can be separately introduced into the reaction system. Moreover, it is preferable to introduce 90% by weight or more of each of the total amount of liquid A, liquid B and liquid C introduced into the reaction system in parallel. Specific examples of the method of introducing the liquid A, the liquid B, and the liquid C into the reaction system include dropping and spraying, and the dropping is preferable from the viewpoint of the viscosity of the liquid A, the liquid B, and the liquid C. The liquid A is preferably a solvent containing water from the viewpoint of the freezing point, and the liquid B is preferably a solvent not containing water from the viewpoint of hydrolysis. The distance between the nozzle for liquid A (introduction port), the nozzle for liquid B (introduction port), and the nozzle for liquid C (introduction port) can be set arbitrarily. Moreover, although dripping can be carried out in air or in liquid, air dripping is preferred from the viewpoint of introducing all of the liquid. The nozzle diameter is preferably smaller from the viewpoint of increasing the surface area of the droplet and the solubility. Thus, by introducing the liquid A and the liquid B separately into the reaction system, the opportunity of contact of the monomer 2 with water is reduced and hydrolysis is suppressed. Moreover, by introducing 90% by weight or more of each of the total amount of liquid A, liquid B and liquid C introduced into the reaction system in parallel into the reaction system, a copolymer in which each monomer is randomly introduced is obtained. can get. In other words, 90% by weight or more of the total amount of the liquid A, the liquid B, and the liquid C means that the amount of the liquid A, the liquid B, and the liquid C that are independently introduced into the reaction system is the liquid A that is introduced into the reaction system. , Liquid B and liquid C are each 10% by weight or less of the total amount.

  Further, in the production of the copolymer according to the present invention, from the viewpoint of versatility with respect to materials, temperature, and blending, the copolymerization molar ratio of monomer 1, monomer 2 and monomer 3 is set to a constant during polymerization. It is preferable to polymerize by changing it more than once.

  The weight average molecular weight (gel permeation chromatography method / polyethylene glycol equivalent) of the copolymer in the present invention is preferably from 5,000 to 200,000, more preferably from 10,000 to 150,000, and more preferably from 15,000 to 100,000 from the viewpoint of fluidity retention. More preferably, 20000-80000 are preferable, 25000-60000 are still more preferable, and 30000-50000 are still more preferable.

  The dispersant for hydraulic composition of the present invention can be used as an aqueous solution containing the copolymer.

<Dispersant for hydraulic composition>
As the dispersant for a hydraulic composition according to the present invention, the copolymer of the present invention can be used alone, but at least selected from carboxylic acid groups, phosphoric acid groups, sulfonic acid groups, and neutralizing groups thereof. You may contain the polymer A which has 1 type (henceforth the polymer A). In general, the polymer A is a polymer known as an admixture (dispersant or the like) for a hydraulic composition. The dispersant for hydraulic composition of the present invention can be used as an aqueous solution containing the copolymer of the present invention and the polymer A.

  Among the polymers A, those having a carboxylic acid group or a neutralizing group thereof are polymers having an oxyalkylene group or a polyoxyalkylene group and a carboxylic acid. For example, a polyalkylene glycol monoester monomer and an acrylic acid polymer into which 110 to 300 moles of an oxyalkylene group having 2 to 3 carbon atoms shown in JP-A-7-223852 are introduced, JP-A-2004-519406. Japanese Patent Application Laid-Open No. 2004-210587, Japanese Patent Application Laid-Open No. 2004-210589, and an amide macromonomer described in Japanese Patent Application Laid-Open No. 2004-210589 -1288738 gazette and JP, 2006-525219, A polymer containing polyethyleneimine is mentioned.

  Commercially available products of polymer A having a carboxylic acid group or a neutralizing group thereof include (1) BASF Pozzolith Co., Ltd. Leo Build SP8LS / 8LSR, SP8LS, SP8LSR, SP8N, SP8S, SP8R, SP8SE / 8RE, SP8SE, SP8RE , SP8SB series (S type, M type, L type, LL type), SP8HE, SP8HR, SP8SV / 8RV, SP8RV, SP8HU, SP9N, SP9R, SP9HS, Leo build 8000 series, (2) Nihon Sika Co., Ltd. SeaCament 1100NT , Seakament 1100NTR, Seakament 2300, (3) Floric's Floric SF500S (500SB), Floric SF500H, Floric SF500R (500RB), (4) Tulip HP-8, HP -11, HP-8R, HP-11R, SSP-104, NV-G1, NV-G5, (5) Nippon Catalyst's Aqualock FC600S, Aqualock FC900, (6) Maria Lim, Nippon Oil & Fat Co., Ltd. AKM, Mariarim EKM, etc. are mentioned, but not limited to this.

  The polymer A having a phosphate group or a neutralizing group thereof is a polymer having a polyoxyalkylene group and a phosphate group. For example, the polymer of Unexamined-Japanese-Patent No. 2006-052381 is mentioned. Specifically, a polyalkylene glycol monoester monomer introduced with an average of 3 to 200 moles of an oxyalkylene group having 2 to 3 carbon atoms, di-[(2-hydroxyethyl) methacrylic acid] ester phosphate, And a copolymer with mono (2-hydroxyethyl) methacrylate ester.

  Among the polymers A, those having a sulfonic acid group or a neutralizing group thereof include naphthalene polymers (for example, Mighty 150: manufactured by Kao Corporation), melamine polymers (for example, Mighty 150V-2: Kao Corporation) ) And aminosulfonic acid polymers (for example, PARIC FP: manufactured by Fujisawa Chemical Co., Ltd.).

  In the dispersant for a hydraulic composition according to the present invention, the content (in terms of solid content) of the copolymer of the present invention is preferably 1 to 99% by weight, more preferably 2 to 80% by weight, and particularly preferably 5 to 70% by weight. Further, the content of the polymer A (in terms of solid content) is 1 to 99% by weight, more preferably 20 to 98% by weight, and particularly preferably 30 to 95% by weight. Two or more dispersants can be used, but the total content is preferably in the above range. Two or more types of polymers A can be used, but the total content is preferably in the above range. The weight ratio of the copolymer of the present invention to the polymer A in the dispersant for hydraulic composition (copolymer of the present invention / polymer A (solid content conversion)) is from the viewpoint of fluidity and fluidity retention. 5 / 95-95 / 5 are preferable, 10 / 90-90 / 10 are more preferable, 15 / 85-85 / 15 are still more preferable, and 20 / 80-80 / 20 are still more preferable.

  In addition to the copolymer and polymer A of the present invention, the dispersant for hydraulic composition according to the present invention includes, for example, a high-performance water reducing agent, AE agent, AE water reducing agent, fluidizing agent, retarder, early strength. In combination with known additives (materials) such as agents, accelerators, foaming agents, foaming agents, antifoaming agents, thickeners, waterproofing agents, antifoaming agents, silica sand, blast furnace slag, fly ash, silica fume, etc. Can do.

<Hydraulic composition>
The hydraulic composition of the present invention contains the above-described dispersant for hydraulic composition of the present invention, hydraulic powder, and water. Further, the polymer A may be contained. When the hydraulic composition of the present invention is obtained, the copolymer of the present invention and the polymer A may be mixed in advance or used separately.

  The hydraulic powder used in the hydraulic composition of the present invention is a powder having physical properties that hardens by a hydration reaction, and examples thereof include cement and gypsum. 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. Blast furnace slag cement, fly ash cement, silica fume cement or the like to which is added may be used. In addition, the hydraulic composition finally obtained by adding sand, sand and gravel as aggregates to these powders is generally called mortar and concrete, respectively. The hydraulic composition of the present invention is used in the field of ready-mixed concrete, concrete vibration products, self-leveling, refractory, plaster, gypsum slurry, lightweight or heavy concrete, AE, repair, pre-packed, tray It is useful in any field of various concrete such as for grouting, for ground improvement, for cold weather.

  In particular, in the production site of ready-mixed concrete, concrete using ordinary Portland cement, moderately hot Portland cement, and blast furnace slag cement is usually co-produced, and concrete of various blends with different water / powder ratios is also produced. Manufacturing has become a daily routine. In such a situation, it is significant that there is little fluctuation in fluidity and fluidity retention depending on the quality of cement. Recently, fluctuations in fluid retention may be confirmed depending on the lot of ordinary Portland cement, and it is meaningful to provide general fluid retention.

  The hydraulic composition of the present invention has a water / hydraulic powder ratio [weight percentage (% by weight) of water and hydraulic powder in the slurry, usually abbreviated as W / P. , W / C may be abbreviated. ] Is preferably 60% by weight or less, more preferably 58-15% by weight, preferably 57-18% by weight, more preferably 56-20% by weight, and still more preferably 55-23% by weight.

  In the hydraulic composition of the present invention, the dispersant for the hydraulic composition of the present invention is 0.02 to 10 parts by weight, further 0.02 to 5 parts by weight, and further 0 to 100 parts by weight of the hydraulic powder. It is preferably added at a ratio of 0.05 to 2 parts by weight (in terms of solid content). Further, the copolymer of the present invention has a ratio (solid content of 0.002 to 5 parts by weight, further 0.01 to 4 parts by weight, and further 0.02 to 2 parts by weight with respect to 100 parts by weight of the hydraulic powder. It is preferable to add by conversion. The polymer A is preferably added in a ratio (converted to solid content) of 0.01 to 8 parts by weight and further 0.02 to 4 parts by weight with respect to 100 parts by weight of the hydraulic powder.

<Production example>
A glass reaction vessel (four-necked flask) with a stirrer was charged with 115.3 g of water, purged with nitrogen while stirring, and heated to 80 ° C. in a nitrogen atmosphere. 77.5 g of ω-methoxypolyethylene glycol monomethacrylate (average added mole number of ethylene oxide 17, moisture 9.8%), 12.5 g of methacrylic acid (indicated as MAA in the table) and 3-mercaptopropionic acid (Sigma Aldrich Japan) Co., Ltd. Reagents) 1.58 g of mixed monomer solution and 2-hydroxyethyl acrylate (referred to as HEA in the table) 42.6 g, ammonium persulfate aqueous solution (I) [Ammonium persulfate (Wako Pure Chemical Industries Ltd.) The company, reagent) 2.45 g dissolved in 45 g of water] started to be added at the same time, and each was added dropwise over 1.5 hours, then ammonium persulfate aqueous solution (II) [ammonium persulfate 0.41 g was added. Water dissolved in 15 g] was added dropwise over 0.5 hours. Thereafter, aging was performed at 80 ° C. for 1 hour. After completion of aging, the mixture was neutralized with a 20% aqueous sodium hydroxide solution to obtain a copolymer (dispersant) of the product 7 of the present invention shown in Table 1. Incidentally, 2-hydroxyethyl acrylate, in the general formula (2) is a compound of R ⁵ is a hydroxyethyl group (molecular weight 116.1), logP value of the compound represented by R ⁵ -OH is -1.369 It is a compound of this. Therefore, 2-hydroxyethyl acrylate has [log P value / molecular weight Mw of monomer 2] of −1.369 / 116.1 = −0.0118.

  Incidentally, ω-methoxypolyethylene glycol monomethacrylate was synthesized by esterification reaction according to the method described in Japanese Patent No. 3879917, and methacrylic acid remaining as an unreacted product was distilled off to less than 1% by weight. Using.

  Other copolymers (dispersants) were produced in the same manner as in the production of the product 7 of the present invention with the monomers and ratios shown in Table 1. The obtained copolymer was used in the following Examples and Comparative Examples.

The symbols in the table have the following meanings. The weight% of the monomer is the weight% in the constituent monomer of the copolymer.
ME-PEG: ω-methoxypolyethylene glycol monomethacrylate, the value in parentheses is the average number of moles of ethylene oxide added.
HEA: 2-hydroxyethyl acrylate (ethylene glycol log P: -1.369, log P / Mw: -1.369 / 116.1 = -0.0118, Wako Pure Chemical Industries, Reagent)
-Methyl acrylate (methanol log P: -0.764, log P / Mw: -0.764 / 86.1 = -0.0089, Wako Pure Chemical Industries, Ltd., reagent)

Example 1 (Paste test)
<Paste formulation>

W: Tap water C1: Ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.)
C2: Blast furnace slag cement (Type B) (manufactured by Taiheiyo Cement Co., Ltd.)
C3: Medium heat cement (manufactured by Taiheiyo Cement Co., Ltd.)

  In a 500 ml container, according to Formulation 1, water containing cement and the dispersant of Table 1 (0.08 parts by weight with respect to 100 parts by weight of cement) is added, kneaded for 2 minutes with a hand mixer (low speed of about 63 rpm), and paste Got. For the following evaluation of initial fluidity and fluidity retention, a paste prepared with C in Formulation 1 as C1 was used.

<Evaluation of initial fluidity and fluidity>
The obtained paste was filled into a cylindrical cone (φ50 mm × 51 mm), and the spread (the longest diameter length and the average value in the vertical direction) when pulled up vertically was measured as a paste flow. The measurement was performed immediately after the end of kneading (after 0 minutes) and 120 minutes after the end of kneading, and the change in flow value with time was measured. As an index of fluid retention, the flow value after 120 minutes / the flow value after 0 minutes × 100 (%) was calculated as the fluid retention. The flow value immediately after completion of kneading was defined as initial fluidity. The initial fluidity when no dispersant was added was 100 mm.

  In this evaluation, if the initial fluidity is 120 mm or more and the flow retention is 90% or more, it can be judged that the dispersant for a hydraulic composition is good. Since the retention tends to decrease when the paste becomes mortar or concrete, it is relatively preferable that the fluid retention rate is larger.

The following considerations can be obtained from the results in Table 3.
As the content of the carboxylic acid monomer increases, the initial fluidity tends to improve. In Comparative Examples 2 and 4 in which the content of the carboxylic acid monomer (monomer 3) is 0 and 2.5% by weight, the initial fluidity is inferior to 120 mm or less. On the other hand, in the product 2 of the present invention in which the content of the carboxylic acid monomer (monomer 3) is 5% by weight, the initial fluidity exceeds 120 mm, 10% by weight (present products 3, 7), 15% by weight ( In the inventive products 1, 4), the initial fluidity was further increased. On the other hand, the fluid retention rate tends to decrease with a decrease in the weight ratio (% by weight) of the monomer 2. The fluid retention is preferably 90% or more practically. In the comparative product 10 in which the content of the monomer 2 is 5% by weight, the initial fluidity is 165 mm, but the fluid retention is inferior at 60%.

<Evaluation of versatility>
Using some of the dispersants in Table 1, evaluations were made on formulations in which C in Formula 1 in Table 2 was C1, C2 or C3. Evaluation was performed about initial fluidity and fluidity retention. The fluid retention was performed in the same manner as the evaluation of the fluid retention. Initial fluidity when C1 (indicated as “normal” in Table 4), C2 (indicated as “blast furnace slag” in Table 4), C3 (indicated as “medium heat” in Table 4) as cements And the fluctuation ratio (standard deviation) of fluidity retention was calculated by the following formula, and used as an index of versatility. The results are shown in Table 4. The smaller the standard deviation, the better the versatility because the same fluidity is exhibited regardless of the type of cement.

  In this evaluation, it can be determined that the smaller the standard deviation, the more versatile. Regarding the initial fluidity, if the standard deviation is preferably 16 or less, more preferably 12 or less, and still more preferably 8 or less, it can be determined that the dispersant is excellent in versatility. Regarding the flow retention, if the standard deviation is preferably 19 or less, more preferably 17 or less, and even more preferably 15 or less, it can be judged that the dispersant is excellent in versatility.

  The C1 to C3 cement used in this evaluation is a typical one with a particularly high use ratio in concrete production, and it is extremely important for a concrete manufacturer that these three kinds of cements have excellent versatility. Blast furnace cement is blended with blast furnace slag, and a dispersant having a large average addition mole number n of oxyalkylene groups has high adsorptivity and high initial fluidity, but on the other hand, fluid retention tends to decrease. There is.

  That is, the comparative product 4 was excellent in the initial fluidity and fluid retention rate with respect to the ordinary cement, but the change in fluidity with respect to the blast furnace slag cement and the medium heat cement was large, and the standard deviation was large. For the comparative product 2 in which the average added mole number n of oxyalkylene groups was 45, the standard deviation was larger than that of the comparative product 4 with n of 28. On the other hand, in the inventive products 5 to 7 (n is 9 to 17) in which the average addition mole number n of the oxyalkylene group is 20 or less (n is 9 to 17), the standard deviation is relatively small, and the versatility is good.

Claims (6)

Copolymer obtained by polymerizing monomer 1 represented by general formula (1), monomer 2 represented by general formula (2), and monomer 3 represented by general formula (3) A dispersant for a hydraulic composition containing a coalescence,
Among the constituent monomers of the copolymer, the ratio of monomer 1 is 25 to 85% by weight, the ratio of monomer 2 is 10 to 70% by weight, and the ratio of monomer 3 is 5 to 5%. The dispersing agent for hydraulic compositions which is 20 weight%.

[Wherein, R ^{1 to} R ³ each represent a hydrogen atom or a methyl group, AO represents an oxyalkylene group having 2 to 4 carbon atoms, n represents an average added mole number of AO, and a number of 5 to 20 R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, q represents an integer of 0 to 2, and p represents 0 or 1. ]

[Wherein R ⁵ is a hydrocarbon group which may contain a hetero atom having 1 to 4 carbon atoms. ]

Wherein, R ⁶ to R ⁸ are each a hydrogen atom, a methyl group or ^{_{(CH 2) s COOM 2,}} (CH 2) s COOM 2 is COOM ¹ or another (CH _{²⁾ s} COOM ₂ and anhydrous In this case, M ¹ and M ² of those groups are not present. s represents the integer of 0-2. M ¹ and M ² 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 least a part of the monomer 2 satisfies the relationship of [log P value of alcohol compound R ⁵ —OH corresponding to R ⁵ in general formula (2) / molecular weight Mw of monomer 2] <− 0.009. The dispersant for hydraulic compositions according to claim 1. The ratio of monomers satisfying the relationship of [log P value of alcohol compound R ⁵ —OH corresponding to R ⁵ in general formula (2) / molecular weight Mw of monomer 2] <− 0.009 is satisfied. The dispersant for a hydraulic composition according to claim 1, wherein the dispersant is 30 mol% or more in 2.   The dispersant for a hydraulic composition according to any one of claims 1 to 3, wherein the ratio of monomer 2 / monomer 3 (weight ratio) is more than 1 in the constituent monomer of the copolymer. The dispersant for hydraulic composition according to any one of claims 1 to 4, wherein R ^{5 in the} general formula (2) is a hydroxyethyl group or a glycerol group.   A hydraulic composition containing the dispersant for hydraulic composition according to any one of claims 1 to 5, a hydraulic powder, and water, wherein the hydraulic powder is ordinary Portland cement, blast furnace slag cement. A hydraulic composition which is a cement selected from moderately heated cement or a mixture thereof.