JP2017186232A - Manufacturing method of water-reducing agent for hydraulic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method capable of easily providing a water-reducing agent for a hydraulic material having extremely excellent dispersion performance.SOLUTION: There is provided a method for manufacturing a water-reducing agent for a hydraulic material, including a process for polymerizing a monomer component containing an unsaturated polyalkylene glycol ether-based monomer (a) and an unsaturated carboxylic acid-based monomer (b) in the presence of hydrogen peroxide, the hydrogen peroxide provides conversion phosphoric acid ion concentration in a hydrogen peroxide 5% solution of 600 mass.ppm or less.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a water reducing agent for hydraulic materials.

Hydraulic materials are generally used in combination with fine aggregates such as water and sand to give hydraulic compositions such as cement paste, mortar and concrete. Usually, various water reducing agents such as polycarboxylic acid-based copolymers are used from the viewpoint of imparting dispersibility (also referred to as fluidity or water reduction) to the hydraulic composition for the purpose of improving workability and durability. ing. The polycarboxylic acid copolymer is a polymer having a -COOM group (M represents a dissociable atom or atomic group), and has high water reducing performance as compared with a conventional water reducing agent such as naphthalene. Demand is growing and attracting attention. Patent Document 1 describes a method for producing a polycarboxylic acid copolymer for cement admixture.

JP 2011-32132 A

As described above, various water reducing agents such as polycarboxylic acid-based copolymers have been developed. However, water reducing performance (also referred to as dispersion performance) can be further exerted, and water reducing agents that are particularly useful for hydraulic materials are provided. There was room for ingenuity.

This invention is made | formed in view of the said present condition, and aims at providing the manufacturing method which provides easily the water reducing agent for hydraulic materials which has the outstanding outstanding dispersibility.

The inventor of the present invention uses a copolymer obtained by polymerizing a monomer component containing an unsaturated polyalkylene glycol ether monomer and an unsaturated carboxylic acid monomer as a water reducing agent for a hydraulic material. As a result of repeated investigations, it was found that the polymerization initiator used in the polymerization reaction greatly affects the water reduction performance of the product copolymer. Specifically, it is preferable to use hydrogen peroxide as a polymerization initiator from the viewpoint of speeding up the polymerization reaction and improving purity, etc., while the physical properties and performance of the copolymer produced depending on the type of hydrogen peroxide. Was found to be different, and the cause was the presence of phosphate ions contained as stabilizers in hydrogen peroxide. Therefore, it has been found that when hydrogen peroxide having a phosphate ion concentration within a predetermined range is used and the polymerization step is carried out in the presence of the copolymer, a copolymer having excellent water reduction performance can be obtained easily and efficiently. It has been found that the polymer is particularly useful as a water reducing agent for hydraulic materials. The inventors have conceived that the above problems can be solved brilliantly, and have completed the present invention.

That is, the present invention is a method for producing a water reducing agent for a hydraulic material, which comprises an unsaturated polyalkylene glycol ether monomer (a) and an unsaturated carboxylic acid in the presence of hydrogen peroxide. A step of polymerizing a monomer component containing a monomer (b), wherein the hydrogen peroxide is a water whose equivalent phosphate ion concentration in a 5% aqueous solution of hydrogen peroxide is 600 mass ppm or less. It is a manufacturing method of the water reducing agent for hard materials.

It is preferable that at least a part of the unsaturated carboxylic acid monomer (b) is sequentially added to the reactor during the polymerization reaction.

The mass ratio (a / b) of the unsaturated polyalkylene glycol ether monomer (a) and the unsaturated carboxylic acid monomer (b) is 50 to 99.9 / 0.1 to 50. Is preferred.

The unsaturated polyalkylene glycol ether monomer (a) is represented by the following general formula (1);
YO (R ¹ O) nR ² (1)
(In the formula, Y represents an alkenyl group having 2 to 8 carbon atoms. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. R ¹ O represents 2 to 18 carbon atoms. 1 or 2 or more types of oxyalkylene groups, wherein n is the average number of moles added of the oxyalkylene group, and is preferably 1 to 500.

The unsaturated carboxylic acid monomer (b) preferably contains an unsaturated monocarboxylic acid monomer.

Since the production method of the present invention has the above-described configuration, it is possible to easily provide a water reducing agent for a hydraulic material that has outstanding dispersion performance. Therefore, since a highly fluid hydraulic composition can be provided with a very small amount of addition to the hydraulic material, and the workability and durability are improved, it can be used in civil engineering and construction fields that handle various hydraulic materials. It makes a great contribution.

Although the preferable form of this invention is demonstrated concretely below, this invention is not limited only to the following description, In the range which does not change the summary of this invention, it can change suitably and can apply. In addition, the form which combined each preferable form of this invention described below 2 or 3 or more also corresponds to the preferable form of this invention.

In this specification, “hydraulic” means a hydrating reaction in the presence of water and a “hydraulic” in a narrow sense that hardens as a solid. It also means “latent hydraulic” in which a hydration reaction takes place in the presence of a small amount of a substance, which hardens as a solid.

〔Production method〕
The production method of the present invention is a step of polymerizing a monomer component containing an unsaturated polyalkylene glycol ether monomer (a) and an unsaturated carboxylic acid monomer (b) in the presence of hydrogen peroxide. including. As long as such a polymerization step is included, one or more other steps may be included as necessary.

The polymerization method in the polymerization step is not particularly limited, and can be performed by a commonly used method such as solution polymerization or bulk polymerization. In view of control of the polymerization reaction and ease of handling of the polymer, solution polymerization is preferable.

The solution polymerization can be carried out either batchwise or continuously. The solvent used here is water; lower alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, cyclohexane, n-hexane. Aromatic hydrocarbons or aliphatic hydrocarbons such as: ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; cyclic ether compounds such as tetrahydrofuran and dioxane. From the monomer component as a raw material and the solubility of the resulting copolymer and convenience during use of the copolymer, at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms is used. It is preferable to use it as a solvent. Among the lower alcohols having 1 to 4 carbon atoms, methanol, ethanol, isopropanol and the like are preferable. At this time, the mixing ratio of water is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and most preferably 1% by mass or less from the viewpoint of the uniformity of the solution.

When the polymerization is performed by a solution polymerization method, the amount of the solvent used is preferably, for example, 20 to 300 parts by mass with respect to 100 parts by mass of the total amount of monomer components. As a result, the viscosity in the reaction solution becomes moderate, more uniform stirring can be performed, a more stable polymer can be obtained, and the polymer concentration in the reaction solution is moderate. Thus, the transportation cost can be reduced. More preferably, it is 30-200 mass parts, More preferably, it is 40-100 mass parts.

The polymerization step is performed in the presence of hydrogen peroxide. That is, hydrogen peroxide is essential as a polymerization initiator. This hydrogen peroxide has a converted phosphate ion concentration of 600 mass ppm or less when a 5% hydrogen peroxide aqueous solution containing 5 mass% of the hydrogen peroxide is used. By carrying out the polymerization in the presence of hydrogen peroxide, the resulting copolymer can exhibit extremely high water reduction performance, and the polymerization reaction is promoted even when the polymerization temperature is low. The decrease in purity and the generation of impurities are sufficiently suppressed. The converted phosphate ion concentration in a 5% aqueous hydrogen peroxide solution is preferably 500 ppm by mass or less, more preferably 400 ppm by mass or less.

In the present specification, the converted phosphate ion concentration in a 5% aqueous solution of hydrogen peroxide can be determined through the following ion chromatography settings and sample pretreatment. That is, after diluting hydrogen peroxide to 1% by mass with ultrapure water (pretreatment), it is measured by ion chromatography under the following conditions, and this is calculated in terms of 5% by mass.
[Apparatus] Ion chromatography ICS-2000 (manufactured by Nippon Dynex)
[Column] Dionex IonPac AS20 (manufactured by Thermo Scientific)
[Eluent] KOH 3-22mM
[Pretreatment] Adjust the initiator concentration to 1% by mass with ultra pure water.

The method of setting the converted phosphate ion concentration in a 5% aqueous solution of hydrogen peroxide within the above range is not particularly limited. For example, hydrogen peroxide with less impurities or purification of hydrogen peroxide to be used was performed. It may be used later in the polymerization step.

The amount of the hydrogen peroxide used is, for example, 0.1% of hydrogen peroxide pure content (that is, not the amount as an aqueous hydrogen peroxide solution, but 100% by mole of the monomer component). It is preferable to set it as 01-30 mol%. Thereby, it becomes possible to fully exhibit the effect of this invention. More preferably, it is 0.01-20 mol%, More preferably, it is 0.1-15 mol%, Especially preferably, it is 0.3-10 mol%, Most preferably, it is 0.5-5 mol%.

In the above polymerization step, one or two or more other polymerization initiators may be used in combination with hydrogen peroxide as necessary, but hydrogen peroxide is added to 100% by mass of the total amount of the polymerization initiator. It is preferable to use 50% by mass or more. More preferably, it is 80 mass% or more.

The method for supplying the hydrogen peroxide (and other polymerization initiator used in combination as necessary) to the reactor is not particularly limited, and may be charged all at once in the initial stage or sequentially. In the case of sequential addition, the addition (dropping) method is not particularly limited as long as it can prevent the generation of a large amount of radicals in a short time during the reaction and can stably synthesize a copolymer having little variation in physical properties. For example, as a method for supplying a polymerization initiator such as hydrogen peroxide, a method in which all of the polymerization initiator is continuously dropped from the start of polymerization; a method in which all of the polymerization initiator is dropped intermittently from the start of polymerization; A method in which a part of the polymerization initiator is charged before and the rest is dropped from the start of the polymerization; a part of the polymerization initiator is charged before the start of polymerization, and the remaining is dropped in the middle of the polymerization reaction; A method of charging a part of the initiator and dropping the remainder intermittently; Among these, the method of charging in a batch at the initial stage is preferable.

In this specification, charging a part of the raw material used for the polymerization reaction into the reactor means that a part of the raw material is added to the reactor before the start of polymerization, and the raw material charged in the reactor Means the raw material present in the reactor at the start of polymerization. The raw material charged into the reactor in this way is also referred to as an initial charged raw material. The raw material added sequentially to the reactor means a raw material added after the start of polymerization. The method for sequentially adding the raw materials is not particularly limited, and examples thereof include a method of dropping continuously or intermittently from the start of polymerization; a method of dropping continuously or intermittently from the middle of the polymerization reaction; and the like. .

In the polymerization step, it is preferable to use one or more reducing compounds in combination with hydrogen peroxide. That is, it is preferable to carry out the polymerization step in the presence of a redox polymerization initiator. Thereby, even if the polymerization temperature is low, the effect that the polymerization reaction is accelerated is further exhibited.

The reducing compound is not particularly limited. For example, amine compounds such as monoethanolamine, diethanolamine, triethanolamine, hydroxylamine, hydroxylamine hydrochloride, hydrazine or salts thereof; formaldehyde sodium sulfoxylate, sodium hydroxymethanesulfinate Organic compounds having a group such as —SH group, —SO ₂ H group, —NHNH ₂ group, —COCH (OH) — group such as hydrate or the like; Invert sugars such as D-fructose and D-glucose Thiourea compounds such as thiourea and thiourea dioxide; L-ascorbic acid, L-ascorbate (for example, sodium L-ascorbate), L-ascorbate, erythorbic acid, erythorbate (for example, sodium erythorbate), eryso Bin ester; and the like. Of these, L-ascorbic acid, erythorbic acid, and salts or esters thereof are preferable. More preferred is L-ascorbic acid, sodium L-ascorbate or L-ascorbic acid ester, and still more preferred is L-ascorbic acid.

The amount of the reducing compound used is not particularly limited, but it is preferable to use a relatively small amount. For example, from the viewpoint of the unreacted residue of the reducing substance, the amount is preferably less than 10 mol% with respect to 100 mol% of the total amount of monomer components. As a result, the amount of the remaining reducing compound is sufficiently reduced, and when the obtained copolymer is neutralized and stored at a high concentration, the precipitation of the crystal derived from the reducing compound is sufficient. This is preferable because it is prevented. More preferably, it is 0.05 mol% or more and less than 10 mol%, More preferably, it is 0.05-5 mol%.

The method for supplying the reducing compound to the reactor is not particularly limited, and it may be charged all at once in the initial stage or sequentially. Preferably, it is a method of sequential addition, which makes it possible to generate radicals generated from the polymerization initiator at a stable concentration. Examples of the method for sequentially adding the reducing compound include the same method as that for hydrogen peroxide described above. Among the sequential addition methods, the entire amount is preferably added dropwise.

In the polymerization step, one or more transition metal salts may be used. By conducting the polymerization in the presence of a transition metal salt, the physical properties of the resulting copolymer are further increased.

Although it does not specifically limit as a transition metal salt, For example, it is preferable to use the salt of at least 1 sort (s) of transition metal selected from the group which consists of Ti, Cr, Fe, Ni, Cu, Zn, Mn, Sn, and V. The salt may be a double salt. Among these, the transition metal salt is preferably an iron salt, a copper salt and / or a manganese salt. Specific examples include, for example, Mohr's salt ((NH ₄ ) ₂ Fe (SO ₄ ) ₂ · 6H ₂ O), iron sulfate (II or III), iron nitrate (II or III), iron chloride (II or III) Iron bromide (II or III), iron acetate (III), iron iodide (II or III), iron (II) fumarate, iron (III) acetylacetonate, iron (II) tetrachloride, dilithium chloride, Manganese (II), manganese bromide (II), manganese iodide (II), manganese formate (II), manganese acetate (II), manganese oxalate (II), manganese (II or III) acetylacetonate, tetrachloride Manganese (II) dilithium, copper chloride (I or II), copper bromide (I or II), copper iodide (I or II), copper cyanide (I or II), copper formate (II), copper acetate (II), oxalic acid (II), copper (II) acetylacetonate, four copper chloride (I) dilithium, and the like.

Although the usage-amount of a transition metal salt is not specifically limited, For example, it is preferable to set it as 100-20000 mass ppb in conversion of a transition metal with respect to the total amount of a monomer component from a viewpoint of economical efficiency. More preferably, it is 200-5000 mass ppb, More preferably, it is 200-5000 mass ppb.

The method for supplying the transition metal salt to the reactor is not particularly limited. For example, when a reducing compound is used in combination with a transition metal salt, (1) a form that exists in the reaction system before the start of dropping of the reducing compound; (2) a form that is added to the reaction system after the start of dropping of the reducing compound; Etc. In the case of (1), the equipment can be omitted because it can be added to a mixable raw material. In the case of (2), consumption of the residual monomer can be promoted.

In the polymerization step, one or more chain transfer agents may be used for the purpose of adjusting the molecular weight. The chain transfer agent is not particularly limited. For example, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, octyl 3-mercaptopropionate, 2 -Thiol chain transfer agents such as mercaptoethanesulfonic acid; secondary alcohols such as isopropanol; phosphorous acid, hypophosphorous acid and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, Bisulfite, dithionite, metabisulfite, and salts thereof (sodium sulfite, potassium sulfite, sodium bisulfite, potassium bisulfite, sodium dithionite, potassium dithionite, sodium metabisulfite, metabisulfite Potassium etc.) lower oxides and salts thereof; It is. Furthermore, for the purpose of adjusting the molecular weight of the copolymer to be obtained, it is also effective to use a monomer having high chain mobility such as (meth) allylsulfonic acid (salt) as “other monomer”. .

The amount of the chain transfer agent used is not particularly limited. For example, from the viewpoint of suppressing gel generation and adjusting the molecular weight of the polymer obtained, the amount of the chain transfer agent is 0.5 to 7.0 with respect to the total amount of monomer components of 100 mol%. It is preferable that it is mol%. More preferably, it is 1.0-5.0 mol%, More preferably, it is 1.5-4.0 mol%.

The method for supplying the chain transfer agent to the reactor is not particularly limited. However, since the chain transfer agent can act as a reducing agent, when the chain transfer agent acts as a reducing agent, the amount of the chain transfer agent in the reaction system decreases, and this results in the molecular weight of the resulting polymer being reduced. It is thought that it becomes the cause that becomes large. Therefore, the chain transfer agent is particularly preferably added dropwise to the polymerization solution from the viewpoint of stably producing a polymer having a small variation in molecular weight.

In the polymerization step, one or more antioxidants may be used for the purpose of ensuring stability during polymerization, oxidation as a compound, and ensuring thermal stability.
The antioxidant is not particularly limited. For example, hindered amine antioxidants such as ADK STAB LA series; phosphorus antioxidants such as ADK STAB PEP series; dibutylhydroxytoluene, trade names IRGANOX 1010, 1035, 1076, 1098, 1135 Hindered phenolic antioxidants typified by; and the like.

In the polymerization step, an acid or alkali may be initially charged for the purpose of adjusting the pH of the initial charge, and it is preferable to adjust the pH of the initial charge by initially adding an acid.
The acid and alkali are not particularly limited as long as they are conventionally known substances that do not adversely affect the polymerization reaction. For example, examples of the acid include p-toluenesulfonic acid, methanesulfonic acid, phosphoric acid, acetic acid, citric acid, sulfuric acid, formic acid, and examples of the alkali include sodium hydroxide, potassium hydroxide, calcium hydroxide, and the like. It is done.

In the polymerization step, the polymerization temperature is preferably set as appropriate depending on the solvent to be used, but is preferably 0 to 95 ° C. from the viewpoint of water reduction performance and productivity improvement of the produced polymer. More preferably, it is 30-90 degreeC, More preferably, it is 50-85 degreeC. The polymerization pressure during the polymerization is not particularly limited, and may be any one of pressurization, normal pressure (atmospheric pressure), and reduced pressure, but normal pressure is preferable.

The monomer component used in the polymerization step includes an unsaturated polyalkylene glycol ether monomer (a) (also referred to as “monomer (a)”) and an unsaturated carboxylic acid monomer ( b) (also referred to as “monomer (b)”). If necessary, it may further contain one or more other monomers (c). Each monomer can be used alone or in combination of two or more.
Hereinafter, each monomer will be further described.

-Monomer (a)-
The unsaturated polyalkylene glycol ether monomer (a) is not particularly limited as long as it is a compound containing a polyalkylene glycol chain, an ether bond, and an unsaturated double bond (carbon-carbon double bond). The following general formula (1):
YO (R ¹ O) _n R ² (1)
(Wherein, Y is .R ² in which an alkenyl group having 2 to 8 carbon atoms are, .R ¹ O represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms are the same or different, carbon It represents one or more of oxyalkylene groups having 2 to 18 atoms, and n is the average number of added moles of oxyalkylene groups, and preferably represents 1 to 500.

In the general formula (1), the carbon atom number of ^{R 1} constituting the oxyalkylene group ^{R 1} O is 2 to 18. Preferably it is 2-8, More preferably, it is 2-4. Specific examples of R ¹ include an ethylene group, a trimethylene group, a methylethylene group, an ethylethylene group, a phenylethylene group, a tetramethylene group, and a 1,2-dimethylethylene group. That is, R ¹ O is preferably an oxyalkylene group having these groups as R ¹ . Among these, from the viewpoint of reactivity in polymerization, R ¹ O is preferably an oxyethylene group or an oxymethylethylene group, and more preferably an oxyethylene group. In particular, it is that (R 1 ^O) all oxyalkylene groups in 100 mole% constituting the _n, it is preferable that an oxyethylene group is not less than 50 mol%, more preferably oxyethylene group is 90 mol% or more .

Two or more types of oxyalkylene groups may be present in the unit represented by (R ¹ O) _n , but considering the ease of production of the polyoxyalkylene chain and the ease of control of the structure Then, it is preferable that the unit represented by (R ¹ O) _n is composed of the same oxyalkylene group. When two or more types of oxyalkylene groups are present, these may be present in any form such as random addition, block addition, and alternate addition.

n represents the average addition mole number of an oxyalkylene group, and is a number of 1-500. Thereby, the hydrophilicity of the obtained copolymer is sufficient and the dispersion performance is improved, and the reactivity in the polymerization process is also sufficient. Preferably it is 1-300, More preferably, it is 1-200, More preferably, it is 1-170, Most preferably, it is 1-150, Most preferably, it is 2-130.
The average added mole number means an average value of the number of moles of the oxyalkylene group added in 1 mole of the monomer (a).

Here, the distribution of the oxyalkylene group is not particularly limited. For example, a monomer having n of 1 to 10 and a monomer having n of 10 to 75 are mixed to broaden the distribution. Alternatively, the oxyalkylene group distribution may be narrowed by synthesis using a Lewis acid or a solid acid catalyst.

Y represents an alkenyl group having 2 to 8 carbon atoms. The number of carbon atoms is preferably 3-8, more preferably 3-5. Specific examples of Y include, for example, vinyl group, allyl group, methallyl group, 3-butenyl group, 3-methyl-3-butenyl group, 3-methyl-2-butenyl group, 2-methyl-3-butenyl group, A 2-methyl-2-butenyl group, a 1,1-dimethyl-2-propenyl group and the like are preferable. Among these, an allyl group, a methallyl group, and a 3-methyl-3-butenyl group are preferable.

R ² is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. As the hydrocarbon group having 1 to 30 carbon atoms, those having no radically polymerizable unsaturated bond are preferable, and an alkyl group having 1 to 30 carbon atoms (aliphatic alkyl group or alicyclic alkyl group); carbon An aromatic group having a benzene ring such as a phenyl group having 6 to 30 atoms, an alkylphenyl group, a phenylalkyl group, a phenyl group substituted with a (alkyl) phenyl group, or a naphthyl group is preferable. However, as the number of carbon atoms in the hydrocarbon group increases, the hydrophobicity increases, and the dispersibility may not be improved sufficiently. Therefore, when R ² represents a hydrocarbon group, the number of carbon atoms is 1 to 22. Is preferred. More preferably, it is 1-18, More preferably, it is 1-12, Most preferably, it is 1-4. Most preferably, R ² represents a hydrogen atom.

The monomer (a) represented by the general formula (1) can be produced by various methods, and typical production methods are as follows.
1) The compound in which R ² represents a hydrogen atom in the general formula (1) is, for example, allyl alcohol, methallyl alcohol, 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol And unsaturated alcohols having an alkenyl group having 3 to 8 carbon atoms such as 2-methyl-2-buten-1-ol, alkali catalysts such as potassium hydroxide and sodium hydroxide, boron trifluoride, A monomer can be obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms in the presence of an acid catalyst such as tin chloride.

2) In the general formula (1), the compound in which R ² represents a hydrocarbon group having 1 to 30 carbon atoms is, for example, an unsaturated alcohol obtained by the above method having 2 to 18 carbon atoms. A monomer is obtained by reacting a compound obtained by adding 1 to 500 moles of an alkylene oxide with a halogenated hydrocarbon having 1 to 30 carbon atoms such as methyl chloride in the presence of an alkali such as sodium hydroxide. Can do.

3) In the general formula (1), the compound in which R ² represents a hydrocarbon group having 1 to 30 carbon atoms is, for example, contrary to the above 2), having 1 to 30 carbon atoms such as methanol and phenol. A compound obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to alcohol or phenol, and further having 3 to 3 carbon atoms such as allyl chloride or methallyl chloride in the presence of an alkali such as sodium hydroxide. Monomers can be obtained by reacting 8 alkenyl halides.

Among the monomers (a) represented by the general formula (1), examples of the compound in which R ² represents a hydrogen atom include (poly) ethylene glycol allyl ether, (poly) ethylene glycol methallyl ether, (poly) ) Ethylene glycol 3-methyl-3-butenyl ether, (poly) ethylene (poly) propylene glycol allyl ether, (poly) ethylene (poly) propylene glycol methallyl ether, (poly) ethylene (poly) propylene glycol 3-methyl- 3-butenyl ether, (poly) ethylene (poly) butylene glycol allyl ether, (poly) ethylene (poly) butylene glycol methallyl ether, (poly) ethylene (poly) butylene glycol 3-methyl-3-butenyl ether, etc. Can be mentioned.

Among the monomers (a) represented by the general formula (1), examples of the compound in which R ² represents a hydrocarbon group having 1 to 30 carbon atoms include methoxy (poly) ethylene glycol allyl ether, methoxy (Poly) ethylene glycol methallyl ether, methoxy (poly) ethylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) propylene glycol allyl ether, methoxy (poly) ethylene (poly) propylene glycol methallyl ether, Methoxy (poly) ethylene (poly) propylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) butylene glycol allyl ether, methoxy (poly) ethylene (poly) butylene glycol methallyl ether, methoxy (poly) ethylene( And poly) butylene glycol 3-methyl-3-butenyl ether.

The method for supplying the monomer (a) to the reactor is not particularly limited, and the monomer (a) may be charged all at once in the initial stage or sequentially. However, since the monomer (a) does not exhibit homopolymerizability, it is preferable to initially charge at least a part of the monomer (a) from the viewpoint of improving the polymerization rate and the polymer content. The proportion of the monomer (a) to be initially charged is preferably 5 to 100% by mass with respect to 100% by mass of the total amount of the monomer (a) used in the polymerization reaction. More preferably, it is 10-100 mass%, More preferably, it is 50-100 mass%, Most preferably, it is 100 mass%.

-Monomer (b)-
The unsaturated carboxylic acid monomer (b) includes a carboxy group and / or a carboxylic acid base (collectively referred to as “carboxylic acid (salt) group”) and an unsaturated double bond (carbon-carbon double bond). If it is a compound containing, it will not specifically limit.

Here, including a carboxylic acid (salt) group means that at least one group represented by —COOM (M represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group) in one molecule. It means having. Examples of the metal atom constituting the carboxylate include alkali metals such as sodium, lithium, potassium, rubidium and cesium; alkaline earth metals such as magnesium, calcium, strontium and barium; aluminum and iron. Examples of the organic amine group include alkanolamine groups such as monoethanolamine group, diethanolamine group and triethanolamine group; alkylamine groups such as monoethylamine group, diethylamine group and triethylamine group; polyamine groups such as ethylenediamine group and triethylenediamine group, etc. Is mentioned. Among these, as the carboxylate, ammonium salt, sodium salt or potassium salt is preferable, and sodium salt is more preferable.

The monomer (b) is not particularly limited, but is an unsaturated monocarboxylic acid monomer having one carboxylic acid (salt) group in one molecule; two carboxylic acids (salts in one molecule) And an unsaturated dicarboxylic acid monomer having a group. Among these, at least an unsaturated monocarboxylic acid monomer is preferably used. That is, the unsaturated carboxylic acid monomer (b) preferably includes an unsaturated monocarboxylic acid monomer. More preferred are acrylic acid, methacrylic acid and / or their salts.

Examples of unsaturated monocarboxylic acid monomers include acrylic acid, methacrylic acid, crotonic acid and their salts; unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, and carbon atoms. Half ester with 1-30 alcohol; Half amide with unsaturated dicarboxylic acid and 1-30 amine; 1-300 moles of alkylene oxide with 2-18 carbon atoms added to the alcohol or amine A half ester of an alkyl (poly) alkylene glycol and an unsaturated dicarboxylic acid; a half ester of an unsaturated dicarboxylic acid and a glycol having 2 to 18 carbon atoms or a polyalkylene glycol having 2 to 300 addition moles of these glycols; Etc.

Examples of the unsaturated dicarboxylic acid-based monomer include maleic acid, itaconic acid, citraconic acid, fumaric acid and salts and anhydrides thereof, and the anhydride includes maleic anhydride, itaconic anhydride, Examples thereof include citraconic anhydride.

The method for supplying the monomer (b) to the reactor is not particularly limited, and the monomer (b) may be charged all at once in the initial stage or sequentially. However, since the monomer (b) exhibits homopolymerizability, it is preferable to sequentially add at least a part of the monomer (b) from the viewpoint of sufficiently suppressing the explosive progress of the polymerization. That is, it is preferable that at least a part of the unsaturated carboxylic acid monomer (b) is sequentially added to the reactor during the polymerization reaction. The method of sequential addition is not particularly limited, but when a part of the monomer (b) is added to the kettle, it is preferable that the polymerization temperature be controlled and the remainder is added. The proportion of the monomer (b) added sequentially is preferably 10 to 100% by mass with respect to 100% by mass of the total amount of the monomer (b) used in the polymerization reaction. More preferably, it is 20-100 mass%, More preferably, it is 30-100 mass%, Especially preferably, it is 60-100 mass%, Most preferably, it is 80-100 mass%.

In the monomer component, the mass ratio (a / b) between the monomer (a) and the monomer (b) is preferably 50 to 99.9 / 0.1 to 50. Thereby, the polymer obtained becomes more excellent in water reduction performance. More preferably, it is 60-99.5 / 0.5-40, More preferably, it is 70-99 / 1-30. Moreover, it is preferable that a monomer (a) is 4-98 mol% with respect to 100 mol% of total amounts of a monomer (a) and a monomer (b). Thereby, a polymerization reaction can be advanced more efficiently. More preferably, it is 6-90 mol%, More preferably, it is 8-80 mol%.

In the present specification, when calculating the proportion of the unsaturated carboxylic acid monomer (b), it is calculated that the monomer (b) is a completely neutralized monomer (salt). And For example, when using acrylic acid as the monomer (b) and completely neutralizing with sodium hydroxide in the polymerization reaction, it is assumed that sodium acrylate is used as the monomer (b). Calculate. In the case where maleic acid is used as the monomer (b) and complete neutralization with sodium hydroxide in the polymerization reaction, disodium maleate is used as the monomer (b). ).

-Monomer (c)-
In the polymerization step, if necessary, the monomer (a) and / or another monomer (c) copolymerizable with the monomer (b) may be further copolymerized. The other monomer (c) is not particularly limited as long as it is copolymerizable with the monomer (a) and / or the monomer (b), and examples thereof include the following compounds.

Diesters of unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid and the like, and alcohols having 1 to 30 carbon atoms; the above unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms; Diesters of an alkyl (poly) alkylene glycol obtained by adding 1 to 300 moles of an alkylene oxide having 2 to 18 carbon atoms to the alcohol or amine and the unsaturated dicarboxylic acid; the unsaturated dicarboxylic acid and carbon Diesters of glycols having 2 to 18 atoms or polyalkylene glycols having an addition mole number of these glycols of 2 to 300; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, glycidyl (meth) acrylate , Methyl crotonate, ethyl croto Esters of unsaturated monocarboxylic acids such as carbonates and propyl crotonates with alcohols having 1 to 30 carbon atoms; maleamic acid and glycols having 2 to 18 carbon atoms or addition moles of these glycols of 2 to 300 Half amides with polyalkylene glycols.

(Poly) alkylene glycols such as triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate, etc. Di (meth) acrylates; polyfunctional (meth) acrylates such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate; triethylene glycol dimaleate, polyethylene glycol (Poly) alkylene glycol dimaleates such as dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acrylate Xylpropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- ( Unsaturated sulfonic acids such as (meth) acryloxybutyl sulfonate, (meth) acrylamide methyl sulfonic acid, (meth) acrylamide ethyl sulfonic acid, 2-methylpropane sulfonic acid (meth) acrylamide, styrene sulfonic acid, and monovalents thereof Metal salts, divalent metal salts, ammonium salts and organic amine salts (organic ammonium salts); Amides of unsaturated monocarboxylic acids and amines having 1 to 30 carbon atoms such as methyl (meth) acrylamide; Styrene, α -Methyl Vinyl aromatics such as styrene, vinyltoluene, p-methylstyrene; 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) Alkanediol mono (meth) acrylates such as acrylate; dienes such as butadiene, isoprene, 2-methyl-1,3-butadiene, and 2-chloro-1,3-butadiene.

Unsaturated amides such as (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; unsaturated cyanides such as (meth) acrylonitrile and α-chloroacrylonitrile Unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, Unsaturated amines such as dibutylaminoethyl acrylate and vinyl pyridine; divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate; (meth) allyl alcohol, glycidyl (meth) allyl ether, etc. Allyls; polydimethyl Roxanpropylaminomaleamic acid, polydimethylsiloxane aminopropylaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- (dipropyleneaminomaleamic acid), polydimethylsiloxane -(1-propyl-3-acrylate), polydimethylsiloxane- (1-propyl-3-methacrylate), polydimethylsiloxane-bis- (1-propyl-3-acrylate), polydimethylsiloxane-bis- (1- Siloxane derivatives such as propyl-3-methacrylate).

The method for supplying the monomer (c) to the reactor is not particularly limited. The monomer (c) may be charged all at once in the initial stage and may be added sequentially, but it is preferable to add them sequentially.

Although the usage-amount of the said monomer (c) is not specifically limited, For example, it is preferable that it is 0-50 mass% with respect to 100 mass% of total amounts of a monomer component. More preferably, it is 0-30 mass%, More preferably, it is 0-20 mass%.

Although the molecular weight of the copolymer obtained by the said polymerization process is not specifically limited, For example, it is preferable that a weight average molecular weight is 1000-1 million. Thereby, water reduction performance can be improved more. More preferably, it is 2500-500,000, More preferably, it is 5000-250,000, Most preferably, it is 10,000-100,000.
In this specification, the weight average molecular weight of a polymer can be measured as a molecular weight in terms of polyethylene glycol under the following measurement conditions by, for example, gel permeation chromatography (hereinafter referred to as “GPC”).

<Measurement conditions>
Column: TSKguardcolumn SWXL + TSKge1 G4000SWXL + G3000SWXL + G2000SWXL (manufactured by Tosoh Corporation)
Eluent: Dissolve 115.6 g of sodium acetate trihydrate in a mixed solvent of 10999 g of water and 6001 g of acetonitrile, and further adjust the pH to 6.0 with acetic acid.
Eluent flow rate: 1.0 mL / min
Column temperature: 40 ° C
Standard substance: Polyethylene glycol (Top peak molecular weight (Mp): 272500, 219300, 85000, 46000, 24000, 12600, 4250, 7100, 1470)
Calibration curve order: Tertiary detector: 2414 Differential refraction detector (trade name, manufactured by Nippon Waters)
Analysis software: Empower2 (trade name, manufactured by Nihon Waters)

The copolymer obtained in the above polymerization step can be used as it is as a main component of the water reducing agent for hydraulic materials, but may be further neutralized with an alkaline substance if necessary. That is, the production method of the present invention may further include a step of neutralizing with an alkaline substance. As the alkaline substance, it is preferable to use inorganic salts such as hydroxides, chlorides and carbonates of monovalent metals and divalent metals; ammonia; organic amines.

(Hydraulic composition)
The water reducing agent for hydraulic materials obtained by the production method of the present invention can be used in addition to hydraulic materials such as narrowly defined hydraulic inorganic particles such as cement and alumina; latent hydraulic inorganic particles such as slag; Thus, the hydraulic composition containing the water reducing agent for hydraulic materials and the hydraulic material obtained by the production method of the present invention is one of the preferred embodiments of the present invention. Among hydraulic materials, cement and blast furnace slag are preferable. More preferred is cement.

As the hydraulic composition, those containing cement, water, and aggregate (fine aggregate, coarse aggregate, etc.) are preferable. Specifically, for example, cement paste, mortar, concrete, ultra-high concrete and the like can be mentioned.

In the hydraulic composition, examples of the cement include Portland cement (ordinary, early strength, ultra-early strength, moderate heat, sulfate-resistant and low alkali types thereof), various mixed cements (blast furnace cement, silica cement, fly Ash cement), white Portland cement, alumina cement, super fast cement (1 clinker fast cement, 2 clinker fast cement, magnesium phosphate cement), grout cement, oil well cement, low exothermic cement (low exothermic blast furnace cement, Fly ash mixed low heat generation type blast furnace cement, cement with high belite content, ultra-high strength cement, cement-based solidified material, eco-cement (cement manufactured from one or more of municipal waste incineration ash and sewage sludge incineration ash), etc. In addition, blast furnace slag, fly-up Interview, cinder ash, clinker ash, husk ash, silica fume, silica powder, a fine powder and gypsum limestone powder may be added. In addition to gravel, crushed stone, granulated slag, recycled aggregate, etc., the aggregates are siliceous, clay, zircon, high alumina, silicon carbide, graphite, chrome, chromic, magnesia. Refractory aggregate such as can be used.

In the hydraulic composition, the unit water amount per 1 m ³ , the amount of cement used, and the water / cement ratio are, for example, a unit water amount of 100 to 185 kg / m ³ , a used cement amount of 250 to 800 kg / m ³ , and water / cement. The ratio (mass ratio) is preferably 0.1 to 0.7. More preferably, the unit water amount is 120 to 175 kg / m ³ , the cement amount used is 270 to 800 kg / m ³ , and the water / cement ratio (mass ratio) is 0.2 to 0.65. The water reducing agent for hydraulic materials can be widely used from poor blending to rich blending, and is effective for both high-strength concrete with a large amount of unit cement and poor blended concrete with a unit cement amount of 300 kg / m ³ or less. .

In the hydraulic composition, the blending ratio of the water reducing agent for hydraulic material is, for example, 0.01 to 10 parts by mass with respect to 100 parts by mass of the total cement mass in terms of solid content of the copolymer. It is preferable to set so. If the amount is less than 0.01 parts by mass, the performance may not be sufficient. On the other hand, if the amount exceeds 10 parts by mass, the effect is substantially peaked, which may be disadvantageous from the viewpoint of economy. More preferably, it is 0.02-8 mass parts, More preferably, it is 0.05-6 mass parts.

The hydraulic composition is effective for ready-mixed concrete, concrete for concrete secondary products (precast concrete), centrifugal molded concrete, vibration compacted concrete, steam-cured concrete, shotcrete, etc., and medium fluidized concrete (Concrete with a slump value of 22 to 25 cm), high fluidity concrete (a concrete with a slump value of 25 cm or more and a slump flow value of 50 to 70 cm), self-filling concrete, self-leveling material, etc. It is also effective for mortar and concrete.

The hydraulic composition may contain one or more known cement dispersants. When a known cement dispersant is included, the blending ratio of the water reducing agent for hydraulic material obtained by the above-described production method of the present invention and the known cement dispersant is the kind, blend and test of the known cement dispersant to be used. Although it is not uniquely determined by the difference of conditions etc., 1-99 / 99-1 are preferable, 5-95 / 95-5 are more preferable as mass ratio (mass%) in conversion of solid content, respectively, 10 -90 / 90-10 are still more preferred.

Examples of known cement dispersants include the following cement dispersants.
Polyalkylaryl sulfonates such as naphthalene sulfonic acid formaldehyde condensates; Melamine formalin sulfonates such as melamine sulfonic acid formaldehyde condensates; Aromatic amino sulfonates such as aminoaryl sulfonic acid-phenol-formaldehyde condensates Various sulfonic acid-based dispersants having a sulfonic acid group in the molecule such as lignin sulfonates such as lignin sulfonates and modified lignin sulfonates; polystyrene sulfonates.
As described in JP-B-59-18338 and JP-A-7-223852, polyalkylene glycol mono (meth) acrylic acid ester monomers, (meth) acrylic acid monomers, and single amounts thereof A copolymer obtained from a monomer copolymerizable with a polymer.
In a molecule such as a copolymer obtained from (alkoxy) polyalkylene glycol mono (meth) acrylate, phosphoric monoester monomer, and phosphoric diester monomer as described in JP-A-2006-52381 And various phosphate dispersants having a (poly) oxyalkylene group and a phosphate group.

The hydraulic composition may also contain one or more other known cement additives (materials) as exemplified in the following (1) to (12).
(1) Water-soluble polymer substances: nonionic cellulose ethers such as methylcellulose, ethylcellulose, carboxymethylcellulose; polysaccharides produced by microbial fermentation such as yeast glucan, xanthan gum, β-1.3 glucans; polyethylene glycol, etc. Polyoxyalkylene glycols; polyacrylamide and the like.
(2) Polymer emulsion: Copolymers of various vinyl monomers such as alkyl (meth) acrylate.
(3) Curing retarder: oxycarboxylic acid or salt thereof such as gluconic acid, glucoheptonic acid, alabonic acid, malic acid, citric acid; sugar and sugar alcohol; polyhydric alcohol such as glycerin; aminotri (methylenephosphonic acid) Phosphonic acid and its derivatives.
(4) Early strengthening agents / accelerators: soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide and calcium iodide; chlorides such as iron chloride and magnesium chloride; sulfates; potassium hydroxide; Sodium hydroxide; carbonate; thiosulfate; formate such as formic acid and calcium formate; alkanolamine; alumina cement; calcium aluminate silicate.

(5) Oxyalkylene-based antifoaming agent: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; polyoxyalkylene alkyl ethers such as diethylene glycol heptyl ether; polyoxyalkylene acetylene ethers; ) Oxyalkylene fatty acid esters; polyoxyalkylene sorbitan fatty acid esters; polyoxyalkylene alkyl (aryl) ether sulfate salts; polyoxyalkylene alkyl phosphate esters; polyoxypropylene polyoxyethylene laurylamine (propylene oxide 1-20) Mole additions, ethylene oxide 1-20 mol adducts, etc.), fatty acid-derived amines obtained from cured beef tallow added with alkylene oxide (propylene oxide 1-20 mol) Additionally, polyoxyalkylene alkyl amines ethylene oxide 20 mol adduct) or the like; polyoxyalkylene amide.
(6) Antifoaming agents other than oxyalkylene type: Mineral oil type, fat type, fatty acid type, fatty acid ester type, alcohol type, amide type, phosphate ester type, metal soap type, silicone type and the like.

(7) AE agent: resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, ABS (alkylbenzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl (phenyl) ether, polyoxyethylene alkyl (phenyl) ether Sulfate ester or a salt thereof, polyoxyethylene alkyl (phenyl) ether phosphate ester or a salt thereof, protein material, alkenyl sulfosuccinic acid, α-olefin sulfonate and the like.
(8) Other surfactants: various anionic surfactants; various cationic surfactants such as alkyltrimethylammonium chloride; various nonionic surfactants; various amphoteric surfactants.
(9) Waterproofing agent: fatty acid (salt), fatty acid ester, fats and oils, silicon, paraffin, asphalt, wax and the like.
(10) Rust inhibitor: nitrite, phosphate, zinc oxide and the like.
(11) Crack reducing agent: polyoxyalkyl ether and the like.
(12) Expansion material: Ettlingite, coal, etc.

The hydraulic composition may further contain one or more other cement additives (materials). Specific examples include a cement wetting agent, a thickening agent, a separation reducing agent, a flocculant, a drying shrinkage reducing agent, a strength enhancing agent, a self-leveling agent, a rust inhibitor, a colorant, and an antifungal agent.

In the hydraulic composition described above, the following embodiments (1) to (6) are exemplified as particularly preferred embodiments for components other than cement, fine aggregate, coarse aggregate, and water.
(1) A combination comprising two components, <1> a water reducing agent for hydraulic materials obtained by the production method of the present invention, and <2> an oxyalkylene-based antifoaming agent. As the oxyalkylene-based antifoaming agent, polyoxyalkylenes, polyoxyalkylene acetylene ethers, polyoxyalkylene alkylamines and the like can be used, and polyoxyalkylene alkylamines are particularly preferable.
In addition, as a compounding mass ratio of <2> oxyalkylene type antifoaming agent, the range of 0.01-20 mass parts is preferable with respect to 100 mass parts of <1> water reducing agents for hydraulic materials.

(2) A combination comprising essentially three components, <1> a water reducing agent for hydraulic materials obtained by the production method of the present invention, <2> an oxyalkylene-based antifoaming agent, and <3> an AE agent.
As the oxyalkylene-based antifoaming agent, polyoxyalkylenes, polyoxyalkylene acetylene ethers, polyoxyalkylene alkylamines and the like can be used, and polyoxyalkylene alkylamines are particularly preferable.
The blending mass ratio of <2> antifoaming agent is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the water reducing agent for hydraulic materials, and <3> the blending mass ratio of AE agent. Is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of cement.

(3) A combination comprising essentially two components: <1> a water reducing agent for hydraulic materials obtained by the production method of the present invention, and <2> a sulfonic acid-based dispersant having a sulfonic acid group in the molecule.
Examples of the sulfonic acid dispersant include lignin sulfonate, naphthalene sulfonic acid formalin condensate, melamine sulfonic acid formalin condensate, polystyrene sulfonate, aminoaryl sulfonic acid-phenol-formaldehyde condensate and the like. An agent or the like can be used.
In addition, as a compounding ratio of the <1> hydraulic material water reducing agent and the <2> sulfonic acid-based dispersant, the mass ratio is preferably 5/95 to 95/5, and more preferably 10/90 to 90/10. .

(4) <1> A combination comprising two components, a water reducing agent for hydraulic material obtained by the production method of the present invention, and <2> a retarder.
As the retarder, oxycarboxylic acids such as gluconic acid (salt) and citric acid (salt), sugars such as glucose, sugar alcohols such as sorbitol, phosphonic acids such as aminotri (methylenephosphonic acid), and the like can be used. However, oxycarboxylic acids are particularly suitable.
In addition, as a compounding ratio of the water reducing agent for <1> hydraulic material and the retarder of <2>, the range of 50/50 to 99.9 / 0.1 is preferable, and 70/30 to 99 / A range of 1 is more preferred.

(5) <1> A combination comprising two components, a water reducing agent for hydraulic materials obtained by the production method of the present invention, and <2> an accelerator.
As the accelerator, soluble calcium salts such as calcium chloride, calcium nitrite and calcium nitrate, chlorides such as iron chloride and magnesium chloride, formates such as thiosulfate, formic acid and calcium formate, and the like can be used.
In addition, as a compounding ratio of <1> hydraulic material water reducing agent and <2> accelerator, a mass ratio of 10/90 to 99.9 / 0.1 is preferable, and 20/80 to 99/1. The range of is more preferable.

(6) <1> A combination comprising two components, ie, a water reducing agent for hydraulic materials obtained by the production method of the present invention, and <2> a material separation reducing agent. The hydraulic composition of this combination is suitable as high fluidity concrete, self-filling concrete, and self-leveling material.
Various thickeners such as nonionic cellulose ethers can be used as the material separation reducing agent.
The mixing ratio of the <1> hydraulic material water reducing agent and the <2> material separation reducing agent is preferably 10/90 to 99.99 / 0.01 in terms of mass ratio, and 50/50 to 99.9. /0.1 is more preferable.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “%” means “mass%” and “parts” means “parts by weight”. In addition, the phosphate ion concentration of hydrogen peroxide (converted phosphate ion concentration when a 5% hydrogen peroxide solution was used) and the molecular weight of the polymer were measured by the methods described above.

<Raw materials>
Abbreviations of raw materials used in the following examples are as follows.
AA: acrylic acid L-As: L-ascorbic acid MPA: 3-mercaptopropionic acid 35% H ₂ O ₂ : hydrogen peroxide 35% aqueous solution PW: ultrapure water monomer (a-1): 3-methyl- Ethylene oxide adduct of 3-buten-1-ol (the average number of moles of ethylene oxide added is 50 moles, including 4.5% by weight of polyethylene glycol)
Monomer (a-2): Ethylene oxide adduct of methallyl alcohol (average number of moles of ethylene oxide added 50 mol, including 2.0% by weight of polyethylene glycol)

The following hydrogen peroxides (A) to (D) were prepared (hereinafter referred to as H ₂ O ₂ (A) or the like). Table 1 shows the measurement result of the converted ion amount when each hydrogen peroxide is a 5% hydrogen peroxide aqueous solution (5% hydrogen peroxide aqueous solution). In addition, as above-mentioned, after diluting hydrogen peroxide with ultrapure water so that it might become 1 mass% (pretreatment), it measured by the ion chromatography of a predetermined condition, and converted this into 5 mass%.

<Production Example 1>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 128.9 g of PW, a monomer (a-) that is an unsaturated polyalkylene glycol ether monomer (a) 1) 261.0 g and p-toluenesulfonic acid monohydrate 1.42 g were charged, the inside of the reaction vessel was purged with nitrogen for 30 minutes with stirring, and 35% H ₂ O ₂ (A) 0.43 g and PW2. An aqueous solution mixed with 01 g was added to the reaction vessel, and then heated to 60 ° C. in a nitrogen atmosphere. After 1 hour, an unsaturated carboxylic acid monomer (b) aqueous solution in which 18.5 g of AA was dissolved in 12.39 g of PW was dropped over 3 hours, and then the unsaturated carboxylic acid monomer (b) aqueous solution started to be dropped. At the same time, an auxiliary raw material aqueous solution in which 0.36 g of L-As and 0.95 g of MPA were dissolved in 21.28 g of PW was dropped over 3.5 hours. Thereafter, the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution (polymer composition 1) of the copolymer (1) of the weight average molecular weight 28000.
Further, the polymer content excluding the peak of the equivalent (2200) of the monomer (a-1) by GPC (gel permeation chromatography) was 88.4%.

<Production Example 2>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 128.9 g of PW, a monomer (a-) that is an unsaturated polyalkylene glycol ether monomer (a) 1) 261.0 g and p-toluenesulfonic acid monohydrate 1.42 g were charged, the inside of the reaction vessel was purged with nitrogen for 30 minutes with stirring, and 35% H ₂ O ₂ (B) 0.43 g and PW2. An aqueous solution mixed with 01 g was added to the reaction vessel, and then heated to 60 ° C. in a nitrogen atmosphere. After 1 hour, an unsaturated carboxylic acid monomer (b) aqueous solution in which 18.5 g of AA was dissolved in 12.39 g of PW was dropped over 3 hours, and then the unsaturated carboxylic acid monomer (b) aqueous solution started to be dropped. At the same time, an auxiliary raw material aqueous solution in which 0.36 g of L-As and 0.95 g of MPA were dissolved in 21.28 g of PW was dropped over 3.5 hours. Thereafter, the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution (polymer composition 2) of the copolymer (2) of the weight average molecular weight 29000.
Further, the polymer content excluding the peak corresponding to the monomer (a-1) (2200) by GPC (gel permeation chromatography) was 88.5%.

<Production Example 3>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 128.9 g of PW, a monomer (a-) that is an unsaturated polyalkylene glycol ether monomer (a) 1) 261.0 g and p-toluenesulfonic acid monohydrate 1.42 g were charged, the inside of the reaction vessel was purged with nitrogen for 30 minutes with stirring, and 35% H ₂ O ₂ (C) 0.43 g and PW2. An aqueous solution mixed with 01 g was added to the reaction vessel, and then heated to 60 ° C. in a nitrogen atmosphere. After 1 hour, an unsaturated carboxylic acid monomer (b) aqueous solution in which 18.5 g of AA was dissolved in 12.39 g of PW was dropped over 3 hours, and then the unsaturated carboxylic acid monomer (b) aqueous solution started to be dropped. At the same time, an auxiliary raw material aqueous solution in which 0.36 g of L-As and 0.95 g of MPA were dissolved in 21.28 g of PW was dropped over 3.5 hours. Thereafter, the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution (polymer composition 3) of the copolymer (3) of the weight average molecular weight 29000 was obtained.
The polymer content excluding the peak corresponding to the monomer (a-1) (2200) by GPC (gel permeation chromatography) was 89.0%.

<Production Example 4>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 128.9 g of PW, a monomer (a-) that is an unsaturated polyalkylene glycol ether monomer (a) 1) 261.0 g and p-toluenesulfonic acid monohydrate 1.42 g were charged, the inside of the reaction vessel was purged with nitrogen for 30 minutes with stirring, and 35% H ₂ O ₂ (D) 0.43 g and PW2. An aqueous solution mixed with 01 g was added to the reaction vessel, and then heated to 60 ° C. in a nitrogen atmosphere. After 1 hour, an unsaturated carboxylic acid monomer (b) aqueous solution in which 18.5 g of AA was dissolved in 12.39 g of PW was dropped over 3 hours, and then the unsaturated carboxylic acid monomer (b) aqueous solution started to be dropped. At the same time, an auxiliary raw material aqueous solution in which 0.36 g of L-As and 0.95 g of MPA were dissolved in 21.28 g of PW was dropped over 3.5 hours. Thereafter, the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution (polymer composition 4) of the copolymer (4) of the weight average molecular weight 27000 was obtained.
Further, the polymer content excluding the peak of the equivalent (2200) of the monomer (a-1) by GPC (gel permeation chromatography) was 87.5%.

<Production Example 5>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, 140.5 g of PW and a monomer (a-) that is an unsaturated polyalkylene glycol ether monomer (a) 2) Charge 562.1 g and AA 1.02 g, purge the reaction vessel with nitrogen for 30 minutes under stirring, and add an aqueous solution containing 1.77 g of 35% H ₂ O ₂ (A) and 24.8 g of PW to the reaction vessel. After the addition, the temperature was raised to 58 ° C. in a nitrogen atmosphere. After 1 hour, an unsaturated carboxylic acid monomer (b) aqueous solution in which 46.8 g of AA was dissolved in 22.0 g of PW was added dropwise over 3 hours, and then the unsaturated carboxylic acid monomer (b) aqueous solution started to be added dropwise. At the same time, an auxiliary raw material aqueous solution in which 0.83 g of L-As and 2.56 g of MPA were dissolved in 96.63 g of PW was dropped over 3.5 hours. Thereafter, the temperature was continuously maintained at 58 ° C. for 1 hour to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution (polymer composition 5) of the copolymer (5) of the weight average molecular weight 28000 was obtained.
The polymer content excluding the peak of the equivalent (2200) of the monomer (a-2) by GPC (gel permeation chromatography) was 91.4%.

<Production Example 6>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, 140.5 g of PW and a monomer (a-) that is an unsaturated polyalkylene glycol ether monomer (a) 2) Charge 562.1 g and 1.02 g of AA, purge the inside of the reaction vessel with nitrogen for 30 minutes with stirring, and add an aqueous solution containing 1.77 g of 35% H ₂ O ₂ (D) and 24.8 g of PW to the reaction vessel. After the addition, the temperature was raised to 58 ° C. in a nitrogen atmosphere. After 1 hour, an unsaturated carboxylic acid monomer (b) aqueous solution in which 46.8 g of AA was dissolved in 22.1 g of PW was added dropwise over 3 hours, and then the unsaturated carboxylic acid monomer (b) aqueous solution started to be added dropwise. At the same time, an auxiliary raw material aqueous solution in which 0.80 g of L-As and 2.56 g of MPA were dissolved in 96.6 g of PW was dropped over 3.5 hours. Thereafter, the temperature was continuously maintained at 58 ° C. for 1 hour to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution (polymer composition 6) of the copolymer (6) of the weight average molecular weight 27000 was obtained.
Further, the polymer content excluding the peak of the equivalent (2200) of the monomer (a-2) by GPC (gel permeation chromatography) was 90.5%.

<Concrete test>
Each polymer composition obtained above was used as a water reducing agent, and concrete tests were conducted under the following conditions.
Raw concrete quantity: 30L
Unit amount: As shown in Table 2.
Cement: Ordinary Portland cement coarse aggregate manufactured by Taiheiyo Cement Co., Ltd .: Ome hard sandstone fine aggregate: Oigawa-based land sand / Kimitsu land sand = 9/1
Antifoaming agent: MA404 (BASF Pozzolith) 0.004 wt% / cement AE agent: MA202 (BASF Pozzolith) 0.002 wt% / cement kneading machine: bread mixer kneading method: stone, half sand, cement, sand The materials were added to the mixer in the order of half amount, and the mixture was kneaded for 10 seconds, and the water reducing agent aqueous solution in which the polymer composition, antifoaming agent and AE agent were dissolved (the weight of the polymer composition, antifoaming agent and AE agent was (Included in the weight of water) was added and kneaded for 120 seconds, and then the ready-mixed concrete was discharged and the physical properties were measured. The results are shown in Table 3.

The following items were confirmed from the results of the above Examples and Comparative Examples.
That is, the measured flow value fluctuates depending on the amount of converted phosphate ions detected from a 5% aqueous solution of hydrogen peroxide, and the phosphate ion concentration in H ₂ O ₂ used for production is specified as found by the inventors. It turned out that the polymer excellent in water reduction performance is obtained by setting it as a range.

Claims (5)

A method for producing a water reducing agent for hydraulic materials,
The production method includes a step of polymerizing a monomer component containing an unsaturated polyalkylene glycol ether monomer (a) and an unsaturated carboxylic acid monomer (b) in the presence of hydrogen peroxide. ,
The method for producing a water reducing agent for a hydraulic material, wherein the hydrogen peroxide has a reduced phosphate ion concentration in a 5% hydrogen peroxide aqueous solution of 600 mass ppm or less. The method for producing a water reducing agent for hydraulic materials according to claim 1, wherein at least a part of the unsaturated carboxylic acid monomer (b) is sequentially added to the reactor during the polymerization reaction. . The mass ratio (a / b) of the unsaturated polyalkylene glycol ether monomer (a) and the unsaturated carboxylic acid monomer (b) is 50 to 99.9 / 0.1 to 50. The manufacturing method of the water reducing agent for hydraulic materials of Claim 1 or 2 characterized by these. The unsaturated polyalkylene glycol ether monomer (a) is represented by the following general formula (1):
YO (R ¹ O) nR ² (1)
(In the formula, Y represents an alkenyl group having 2 to 8 carbon atoms. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. R ¹ O represents 2 to 18 carbon atoms. 1 or 2 or more of the oxyalkylene groups in the formula, wherein n is the average number of added moles of the oxyalkylene group and represents the number of 1 to 500. 4. A method for producing a water reducing agent for hydraulic material according to any one of 3 above. The said unsaturated carboxylic acid-type monomer (b) contains an unsaturated monocarboxylic acid-type monomer, The manufacturing method of the water reducing agent for hydraulic materials in any one of Claims 1-4 characterized by the above-mentioned. .