JP2015048392A - Method of producing water-soluble copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means of suppressing minimally the daily chromaticity change after production of a water-soluble copolymer (aqueous solution), which is obtained by using a relatively large amount of reductive compound as a redox type initiator to achieve a sufficient rate of polymerization.SOLUTION: A method of producing a water-soluble copolymer includes polymerizing a carboxylic acid monomer of formula (1) with monomer ingredients containing a polyether monomer of formula (2) as essential component by using a polymerization initiator, and a combination of hydrogen peroxide and more than 0.5 mol%, relative to the total amount of the monomer ingredients of 100 mol%, of a reductive compound is used as the polymerization initiator. The polymerization is carried out in the presence of a transition metal salt, or a transition metal salt is added to the reaction system after the polymerization.

Description

  The present invention relates to a method for producing a water-soluble copolymer.

  A polycarboxylic acid copolymer obtained by copolymerizing a monomer component containing a carboxylic acid monomer and a polyether monomer such as an unsaturated polyalkylene glycol monomer as essential components has been conventionally used. It is suitably used for various dispersants including cement dispersants and pigment dispersants.

  For example, in Patent Document 1, polyalkylene glycol mono (meth) acrylic acid ester monomers, (meth) acrylic acid monomers, and monomers copolymerizable therewith, such as benzoyl peroxide, lauroperoxide, etc. A polycarboxylic acid-based copolymer is produced using a hydroperoxide such as peroxide, cumene hydroperoxide, and an aliphatic azo compound such as azobisisobutyronitrile as a polymerization initiator.

  However, in such a reaction system of a carboxylic acid monomer and a polyether monomer such as an unsaturated polyalkylene glycol monomer, the polymerization rate of the monomer is high when reacted at a high temperature, A problem arises in that the amount of oligomers having a low molecular weight increases, and the effective polymer portion having a high molecular weight that can exhibit performance as a dispersant tends to decrease. On the other hand, when the reaction is carried out at a low temperature, since the chain transfer of the monomer can be suppressed, a water-soluble copolymer having a small amount of oligomer part and a large amount of effective polymer part can be obtained, but the polymerization rate of the monomer tends to be low. .

  In order to solve this problem, when obtaining the water-soluble copolymer, it may be possible to react at a low temperature and to increase the reaction time in order to increase the polymerization rate of the monomer. Since it requires, productivity and workability | operativity are bad, and cost becomes a problem when implementing industrially.

  Therefore, it is desired to use a polymerization initiator having high reactivity even at a low temperature in the reaction system. Conventionally, persulfates such as ammonium persulfate and sodium persulfate have been proposed as polymerization initiators for meeting such demands. However, when a persulfate such as ammonium persulfate as an initiator is used without any ingenuity, the stainless steel reaction kettle is likely to corrode due to sulfuric acid generated during polymerization. It is necessary to use a reaction kettle. Glass-lined reaction kettles have lower thermal conductivity than stainless steel reaction kettles, have poor efficiency during heating and cooling, are vulnerable to shocks, and are difficult to repair when the lining layer breaks. There is a problem that it is expensive to maintain.

  In addition, when used as a cement dispersant, polycarboxylic acid is usually preferably neutralized after polymerization in order to make it easy to handle, but the water-soluble property obtained using persulfate as an initiator. The copolymer tends to generate a salt during neutralization, and this salt may precipitate as crystals and cause various troubles. Furthermore, since the aqueous solution of the water-soluble copolymer obtained by using persulfate as an initiator may be colored brown, it is not suitable for use as a pigment dispersant where there is a high demand for a dispersant with less coloring. Met.

  In order to solve such problems and to provide a water-soluble copolymer having high physical properties and little coloring, Patent Document 2 discloses a redox comprising hydrogen peroxide and L-ascorbic acid as a polymerization initiator. In this case, the amount of hydrogen peroxide used is 0.01 to 30 mol% based on the total amount of monomers, and the pH of the polymerization reaction solution is within a predetermined range (3.2 to 7). 0.0), a technique for carrying out polymerization under control is disclosed.

JP 59-18338 JP 2006-291213 A

  As described above, according to Patent Document 2, it is said that a polymer with less coloring can be obtained by producing a water-soluble copolymer using the above-described method. However, according to the study of the present inventor, when a water-soluble copolymer is produced using the monomer described in Patent Document 2, a reducing compound typified by L-ascorbic acid is used. The chromaticity of the polymer (aqueous solution) gradually changed, and it was found that it was difficult to maintain the quality of the appearance when the product was stored for a long time. And in order to achieve a sufficient polymerization rate, it is necessary to increase the amount of the reducing compound used, but it has also been found that increasing the amount of the reducing compound increases the chromaticity change as described above. .

  Therefore, the present invention provides chromaticity over time after the production of the resulting water-soluble copolymer (aqueous solution) when a relatively large amount of reducing compound is used as a redox initiator in order to achieve a sufficient polymerization rate. An object is to provide means capable of minimizing changes.

  In order to solve the above-mentioned problems, the present inventor has devised and studied variously and repeated experiments. As a result, it has been found that the above-mentioned problems can be solved by performing polymerization in the presence of a transition metal salt using a redox initiator composed of hydrogen peroxide and a large amount of a reducing compound, thereby completing the present invention. It came.

  That is, according to one embodiment of the present invention, the following chemical formula 1:

Where
R ¹ , R ² and R ³ are each independently a hydrogen atom, a methyl group or — (CH ₂ ) _z COOM ² group (— (CH ₂ ) _z COOM ² is —COOM ¹ or other — (CH ₂ ) _z COOM ² may form an anhydride), z represents an integer of 0-2,
M ¹ and M ² each independently represent a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an ammonium group or an organic amine group.
A carboxylic acid monomer represented by
The following chemical formula 2:

Where
R ⁴ and R ⁵ each independently represents a hydrogen atom or a methyl group,
AO each independently represents one or more oxyalkylene groups having 2 or more carbon atoms,
n represents the number of 1 to 300 in terms of the average number of moles added of the oxyalkylene group,
x represents an integer of 0 to 2;
y represents 0 or 1,
R ⁶ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms,
There is provided a method for producing a water-soluble copolymer, which comprises polymerizing a monomer component containing a polyether monomer represented by formula (1) as an essential component using a polymerization initiator.

  And the manufacturing method which concerns on the said form uses together hydrogen peroxide and a reducing compound more than 0.5 mol% with respect to 100 mol% of total amounts of a monomer component as a polymerization initiator, It is characterized in that the polymerization is carried out in the presence of.

  Further, the production method according to another aspect of the present invention uses, as a polymerization initiator, hydrogen peroxide and a reducing compound in an amount of more than 0.5 mol% with respect to 100 mol% of the total amount of monomer components. And a step of performing polymerization and a step of adding a transition metal salt to the reaction system after completion of the polymerization.

  According to the method for producing a water-soluble copolymer according to one aspect of the present invention, when a relatively large amount of a reducing compound is used as a redox initiator to achieve a sufficient polymerization rate, the water-soluble copolymer obtained is obtained. It becomes possible to minimize the change in chromaticity over time after the production of the coalescence (aqueous solution).

  In the method for producing a water-soluble copolymer according to one embodiment of the present invention, a single monomer containing a carboxylic acid monomer represented by Chemical Formula 1 and a polyether monomer represented by Chemical Formula 2 as essential components. The monomer component is polymerized using a polymerization initiator.

  Specifically, the carboxylic acid monomer has the following chemical formula 1:

It is represented by

In Chemical Formula 1, R ¹ , R ² and R ³ each independently represent a hydrogen atom, a methyl group or a — (CH ₂ ) _z COOM ² group. In this case, — (CH ₂ ) _z COOM ² may form an anhydride with —COOM ¹ or other — (CH ₂ ) _z COOM ² . Z represents an integer of 0-2. In Chemical Formula 1, M ¹ and M ² each independently represent a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an ammonium group, or an organic amine group (organic ammonium group). Here, examples of the alkali metal atom include lithium, sodium, potassium, and the like. Examples of alkaline earth metal atoms include calcium and magnesium. Among these, M ¹ and M ² are preferably a hydrogen atom, sodium, or potassium. The ammonium group is a functional group represented by “—NH ₄ ⁺ ”. Examples of the organic amine group (organic ammonium group) include alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine; alkylamines such as monoethylamine, diethylamine, and triethylamine; and organic amines such as polyamines such as ethylenediamine and triethylenediamine. Examples include amine-derived residues.

  Examples of the carboxylic acid monomer represented by the chemical formula 1 include unsaturated monocarboxylic acid compounds such as acrylic acid, methacrylic acid, crotonic acid and their metal salts, ammonium salts, organic amine salts (organic ammonium salts), and the like. Examples of unsaturated dicarboxylic acid compounds include maleic acid, itaconic acid, citraconic acid, fumaric acid, or metal salts, ammonium salts, organic amine salts (organic ammonium salts) thereof, and the anhydrides thereof. Examples thereof include maleic anhydride, itaconic anhydride, citraconic anhydride, and the like. Of these, acrylic acid, methacrylic acid, maleic acid, maleic anhydride or salts thereof are preferable from the viewpoint of polymerizability, and acrylic acid or methacrylic acid is particularly preferable. In addition, only 1 type of these compounds may be used independently, and 2 or more types may be used together. Moreover, these compounds may use commercially available compounds, or may be prepared by synthesizing themselves.

  Meanwhile, the polyether monomer has the following chemical formula 2:

It is represented by

In Chemical Formula 2, R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group. AO independently represents one or more oxyalkylene groups having 2 or more carbon atoms. Examples of “A” constituting such an oxyalkylene group 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, in Chemical Formula 2, “AO” is an oxyalkylene group (for example, oxyethylene group) containing the above functional group. Especially, from the reactive viewpoint in superposition | polymerization, it is preferable that A is an ethylene group or a methylethylene group, and it is most preferable that it is an ethylene group. In some cases, two or more different AO structures may exist in the repeating unit represented by (AO) _n . However, considering the ease of production of the polyoxyalkylene chain and the ease of control of the structure, the repeating structure represented by (AO) _n is preferably a repetition of the same AO structure. When two or more different AO structures exist, these different AO structures may exist in any form such as random addition, block addition, and alternate addition.

In the chemical formula 2, n is an average addition mole number of the oxyalkylene group and represents a number of 1 to 300, preferably 1 to 250, more preferably 1 to 200, still more preferably 1 to 170, particularly Preferably it is 1-150, Most preferably, it is 2-130.
If the average addition mole number n of an oxyalkylene group is more than the lower limit mentioned above, it is preferable because the hydrophilicity of the resulting polymer is ensured and the dispersion performance can be improved. Moreover, it is preferable if the average addition mole number n of an oxyalkylene group is below the upper limit mentioned above, since the reactivity in the reaction step can be sufficiently ensured. The “average number of moles added” means the average number of moles of oxyalkylene groups added in 1 mole of polyether monomer.

  The distribution of the oxyalkylene group is not limited. For example, the distribution may be broadened by mixing n having 1 to 10 and 10 to 75, or using a Lewis acid or a solid acid catalyst. By synthesizing, the distribution of the oxyalkylene group may be narrowed.

In Chemical Formula 2, x represents an integer of 0 to 2, and y represents 0 or 1. R ⁶ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. Here, as the hydrocarbon group having 1 to 20 carbon atoms, for example, an alkyl group having 1 to 20 carbon atoms (aliphatic alkyl group or alicyclic alkyl group), a phenyl group having 6 to 20 carbon atoms, Examples thereof include an aromatic group having a benzene ring such as an alkylphenyl group, a phenylalkyl group, a phenyl group substituted with an (alkyl) phenyl group, and a naphthyl group. In R ₆ , as the number of carbon atoms in the hydrocarbon group increases, the hydrophobicity increases and the dispersibility decreases. Therefore, the number of carbon atoms when R ₆ is a hydrocarbon group is more preferably 1-18. 1 to 12 are more preferable, and 1 to 4 are particularly preferable. Furthermore, R ⁶ is most preferably a methyl group or a hydrogen atom.

  Examples of the polyether monomer represented by Chemical Formula 2 include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 1-hexanol, octanol, and 2-ethyl-1. -C1-C20 saturated aliphatic alcohols such as hexanol, nonyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol, allyl alcohol, methallyl alcohol, crotyl alcohol, oleyl alcohol, etc. C3-C20 alicyclic alcohols such as saturated aliphatic alcohols, cyclohexanol, phenol, phenylmethanol (benzyl alcohol), methylphenol (cresol), p-ethylphenol, dimethylphenol (xylenol) Alkoxy polyalkylene glycols obtained by adding an alkylene oxide having 2 to 18 carbon atoms to any of aromatic alcohols having 6 to 20 carbon atoms such as nonylphenol, dodecylphenol, phenylphenol, naphthol and the like; Examples include esterified products of polyalkylene glycols obtained by polymerizing 18 alkylene oxides with (meth) acrylic acid and crotonic acid, and one or more of these can be used. Of these, esters of alkoxypolyalkylene glycols of (meth) acrylic acid are preferred. Further, vinyl alcohol, (meth) allyl alcohol, 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl- The compound which added 1-300 mol of alkylene oxides to unsaturated alcohols, such as 2-buten-1-ol and 2-methyl-3-buten-1-ol, can be mentioned, These 1 type or 2 types or more are used. be able to. Among these, compounds using (meth) allyl alcohol and 3-methyl-3-buten-1-ol are particularly preferable. In addition, said unsaturated ester and unsaturated ether are arbitrary 1 type chosen from C2-C18 alkylene oxides, such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, as alkylene oxide, Alternatively, two or more alkylene oxides may be added. When two or more types are added, any of random addition, block addition, and alternate addition may be used.

  Hereinafter, each of the two forms will be described in more detail.

(First form)
Examples of the polyether monomer represented by the chemical formula 2 include polyalkylene glycols such as polyethylene glycol and polypropylene glycol, or one having one terminal thereof substituted with a hydrocarbon group having 1 to 20 carbon atoms (meth) Examples include esterified products (polyalkylene glycol ester compounds) with carboxylic acid compounds such as acrylic acid. Such esterified products can be synthesized by referring to known knowledge.

  When such a polyalkylene glycol ester compound is used as a raw material (polyether monomer) in the reaction step of the present invention and reacted with the above-described carboxylic acid monomer in the presence of a polymerization initiator, polyalkylene glycol is obtained. Radical polymerization of unsaturated double bonds of the ester compound (polyether monomer) and the carboxylic acid monomer proceeds, and these copolymers are obtained.

  Although there is no restriction | limiting in particular about the usage-amount of the raw material compound (monomer) mentioned above, As a preferable form, with respect to 100 weight% of total amount of the two raw material compounds (monomer) mentioned above, a polyalkylene glycol ester type compound ( (Polyether monomer) and carboxylic acid monomer are preferably contained in an amount of 1% by weight or more. Further, the content of the polyalkylene glycol ester compound (polyether monomer) is preferably 5% by weight or more, more preferably 10% by weight or more, and further preferably 20% by weight or more. Preferably it is 40 weight% or more. By setting it as such a form, it is excellent in the dispersion performance at the time of using the obtained copolymer as a cement admixture. From the viewpoint of allowing the polymerization reaction to proceed smoothly, the repeating unit derived from the polyalkylene glycol ester compound (polyether monomer) is 50 mol% or less of the total repeating units of the copolymer to be obtained. Is preferred. Furthermore, it is preferable that a carboxylic acid monomer contains (meth) acrylic acid (salt) essential from a viewpoint of improving the dispersion performance at the time of use as a cement admixture.

  In the reaction step of the first embodiment, in addition to the two raw material compounds (monomers) described above, other monomers copolymerizable with these may be further copolymerized. The amount of the other monomer used is preferably 0 to 70% by weight, more preferably 0 to 50% by weight, based on 100% by weight of the total amount of the raw material compound (monomer). Preferably it is 0-30 weight%, Most preferably, it is 0-10 weight%. The other monomer is not particularly limited as long as it is a compound copolymerizable with the above-described polyalkylene glycol ester compound (polyether monomer) and a carboxylic acid monomer, and one of the following compounds or Two or more can be used.

  Half esters and diesters of unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid and citraconic acid and alcohols having 1 to 30 carbon atoms; the above unsaturated dicarboxylic acids and 1 to 30 carbon atoms Half-amides and diamides with amines: Half-esters and diesters of alkyl (poly) alkylene glycols 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 acids Half-esters and diesters of the above unsaturated dicarboxylic acids with glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 300 addition moles of these glycols; methyl (meth) acrylate, ethyl (meth) acrylate , Propyl (meth) acrylate, Esters of unsaturated monocarboxylic acids such as ricidyl (meth) acrylate, methyl crotonate, ethyl crotonate, propyl crotonate and alcohols having 1 to 30 carbon atoms; maleamic acid and glycols having 2 to 18 carbon atoms or Half amides of these glycols with polyalkylene glycols having an addition mole number of 2 to 300.

  (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 -Mechi 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).

  In the method for producing a water-soluble copolymer according to one embodiment of the present invention, the polymerization method is not particularly limited, and a known method such as solution polymerization or bulk polymerization can be employed. In particular, solution polymerization is preferable in consideration of reaction control and ease of handling of the polymer.

  Polymerization in a solvent 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, Examples include aromatic or aliphatic hydrocarbons such as n-hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; and cyclic ether compounds such as tetrahydrofuran and dioxane. From the solubility of the monomer component as a raw material and the obtained copolymer and the 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 preferably used as a solvent. In that case, methanol, ethanol, isopropanol and the like are particularly effective among the lower alcohols having 1 to 4 carbon atoms. At this time, the mixing ratio of water is preferably 20% by weight or less, more preferably 10% by weight or less, still more preferably 5% by weight or less, and most preferably 1% by weight or less from the viewpoint of the uniformity of the solution. .

  In the method for producing a water-soluble copolymer according to one embodiment of the present invention, hydrogen peroxide and a reducing compound are used in combination as a polymerization initiator (a so-called redox polymerization initiator is used). By using such a redox polymerization initiator, there is an advantage that the polymerization reaction can be accelerated rapidly even when the polymerization temperature is low. Here, the amount of hydrogen peroxide used is preferably 0.01 to 30 mol%, more preferably 0.1 to 20 mol%, and still more preferably 0 to the total amount of monomer components. 5 to 10 mol%. With such a configuration, polymerization can be performed in a short time even at a low temperature, the amount of oligomer can be reduced, and coloring can be prevented. In addition, when ammonium persulfate / sodium hydrogen sulfite is used as a redox polymerization initiator, salts such as sodium sulfate are precipitated in the product after polymerization, resulting in a decrease in purity. On the other hand, when a peroxide is used, it is necessary to increase the polymerization temperature as compared with the case where a redox polymerization initiator is used in order to increase the reaction efficiency. For this reason, there is a problem that impurities are easily generated due to a high-temperature reaction, and the product is colored in some cases. On the other hand, the use of hydrogen peroxide as part of the redox polymerization initiator can suppress the occurrence of these problems.

Further, as the redox polymerization initiator according to the present invention, a reducing compound is used in combination with hydrogen peroxide. Examples of such reducing compounds include amine compounds such as monoethanolamine, diethanolamine, triethanolamine, hydroxylamine, hydroxylamine hydrochloride, hydrazine or salts thereof; sodium formaldehyde sulfoxylate, sodium hydroxymethanesulfinate dihydrate Organic compounds having a group such as —SH group, —SO ₂ H group, —NHNH ₂ group, —COCH (OH) — group or the like thereof; or invert sugars such as D-fructose and D-glucose; thiourea, Examples include thiourea compounds such as thiourea dioxide; L-ascorbic acid, sodium L-ascorbate, L-ascorbic acid ester, erythorbic acid, sodium erythorbate, and erythorbic acid ester. As the reducing compound, L-ascorbic acid, erythorbic acid and salts or esters thereof are preferably used, more preferably L-ascorbic acid, sodium L-ascorbate, or L-ascorbic acid ester is particularly preferable. L-ascorbic acid is used.

  In the present invention, the reducing compound used in combination with hydrogen peroxide as a redox polymerization initiator is used in a relatively large amount. Specifically, the amount of the reducing compound used is more than 0.5 mol%, preferably 0.55 to 10 mol%, based on the total amount of monomer components of 100 mol%, from the viewpoint of polymerization reaction efficiency. More preferably, it is 0.6-5 mol%. If the amount of the reducing compound used is 10 mol% or less with respect to 100 mol% of the total amount of the monomer components, the amount of the remaining reducing compound is reduced, and the obtained water-soluble copolymer is used in the medium. Since precipitation of the crystal | crystallization derived from a reducing compound at the time of adding and preserve | saving at high concentration is prevented, it is preferable.

Further, one embodiment of the present invention is characterized in that polymerization is performed in the presence of a transition metal salt. There are no particular restrictions on the specific types of transition metal salts, and conventionally known knowledge can be referred to as appropriate, but an example is selected from the group consisting of iron, manganese, copper, tin, titanium, chromium, and vanadium. One or more of transition metal salts are particularly effective. The salt may be a double salt. Especially, it is preferable that a transition metal salt is 1 type, or 2 or more types selected from the group which consists of iron salt, copper salt, and manganese salt. Specific examples of such transition metal salts include molle salts ((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 (III) acetate, iron iodide (II or III), iron (II) fumarate, iron (III) acetylacetonate, iron tetrachloride (II ) Dilithium, manganese chloride (II), manganese bromide (II), manganese iodide (II), manganese formate (II), manganese acetate (II), manganese oxalate (II), manganese (II or III) acetyl Acetonate, manganese tetrachloride (II) dilithium, copper chloride (I or II), copper bromide (I or II), copper iodide (I or II), copper cyanide (I or II), copper formate ( I), copper acetate (II), copper oxalate (II), copper (II) acetylacetonate, four copper chloride (I) dilithium, and the like. Although there is no restriction | limiting in particular about the usage-amount of these transition metal salts, From a viewpoint of economical efficiency, Preferably it is 100-20000 weight ppb in conversion of a transition metal with respect to a polyether monomer, More preferably, it is 200. It is -5000 weight ppb, More preferably, it is 200-5000 weight ppb.

  The polymerization temperature is appropriately determined depending on the solvent used and the polymerization initiator, but is preferably 0 to 95 ° C, more preferably 30 to 90 ° C, and particularly preferably 50 to 85 from the viewpoint of color tone and / or productivity. ° C. The polymerization pressure during the polymerization in the production method of the present invention is not particularly limited, and may be any one of pressurization, normal pressure (atmospheric pressure), and reduced pressure, and may be appropriately set depending on circumstances, but normal pressure is preferable.

  A chain transfer agent may be used for the purpose of adjusting the molecular weight of the obtained water-soluble copolymer. 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 Lower oxides of potassium sulfite and the like and salts thereof; And the like. These may be used alone or in combination of two or more. 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”. is there.

  Furthermore, you may use antioxidant for the purpose of ensuring the stability at the time of superposition | polymerization, or ensuring the oxidation as a compound, and thermal stability. The antioxidant is not particularly limited. For example, a hindered amine antioxidant such as ADK STAB LA series; a phosphorus antioxidant such as ADK STAB PEP series; dibutylhydroxytoluene, trade names IRGANOX 1010, 1035, 1076, 1098, 1135, etc. And hindered phenol-based antioxidants. These may be used alone or in combination of two or more.

  Furthermore, an acid or alkali may be initially charged for the purpose of adjusting the pH of the initial charge. Preferably, the acid is initially charged to adjust the pH of the initial charge. As the acid and alkali that can be used for such a purpose, any conventionally known substance that does not adversely affect the polymerization reaction can be used without particular limitation. For example, the acid includes p-toluenesulfonic acid, methanesulfonic acid, phosphoric acid, acetic acid, citric acid, sulfuric acid, formic acid and the like. Examples of the alkali include sodium hydroxide, potassium hydroxide and calcium hydroxide.

  In addition, there is no restriction | limiting in particular about the supply form to the reaction system of the polymerization initiator mentioned above, you may charge in a lump at an initial stage, and may add to a reaction system by dripping. When the polymerization initiator is added dropwise to the reaction system, the addition (dropping) method is to prevent the generation of a large amount of radicals in a short time during the reaction, and to stably produce a water-soluble copolymer with little variation in physical properties. Although it is not particularly limited as long as it can be synthesized, for example, a method of continuously dropping all polymerization initiators from the start of polymerization, a method of dropping all polymerization initiators intermittently from the start of polymerization, polymerization before the start of polymerization A method in which a part of the initiator is charged 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 remainder is dropped from the middle of the polymerization reaction, or a polymerization is started before the start of the polymerization For example, a method of charging a part of the agent and intermittently dropping the rest.

  In addition, the production method according to the present invention preferably includes a step of dropping a reducing compound into the reaction system separately from the polymerization initiator from the viewpoint of promoting stable radical generation. By adding the reducing compound dropwise, it is possible to generate radicals generated from the polymerization initiator at a stable concentration. In addition, as a method of dripping a reducing compound to a reaction system, it can be set as the method similar to the method of dripping the polymerization initiator mentioned above to a polymerization solution.

  Further, when the polymerization is carried out in the presence of a transition metal salt, there is no particular limitation on the supply form of the transition metal salt to the polymerization reaction system. For example, (1) a form that exists in the reaction system before the start of dropping of the reducing compound described above; a form that is added to the reaction system after the start of dropping of the reducing compound described above, and the like. In the case of the form (1), the equipment can be omitted because it can be added to the mixable raw material. In the case of the form (2), the consumption of the residual monomer can be promoted.

(Second form)
On the other hand, an alkylene oxide is added to an unsaturated alcohol such as vinyl alcohol, (meth) allyl alcohol, isoprene alcohol (isoprenol; 3-methyl-3-buten-1-ol), 3-methyl-3-buten-2-ol, etc. An alkylene oxide adduct (polyalkylene glycol ether compound) of an unsaturated alcohol obtained by adding ~ 300 mol can also be used as the polyether monomer represented by Formula 2. Such alkylene oxide adducts can also be synthesized by referring to conventionally known knowledge.

  When such a polyalkylene glycol ether compound (polyether monomer) is used as a raw material in the reaction step of the present invention and reacted with the above-described carboxylic acid monomer in the presence of a polymerization initiator, polyalkylene glycol is obtained. The radical polymerization of unsaturated double bonds of the ether compound (polyether monomer) and the carboxylic acid monomer proceeds, and these copolymers are obtained (see Examples described later).

  Note that, as the details of the reaction in the second form, the details of the reaction in the above-described first form can be used in the same manner, and thus the description thereof is omitted here.

(Other forms)
As described above, according to another aspect of the present invention, there is also provided a method for producing a water-soluble copolymer that does not require “polymerization in the presence of a transition metal salt” as an essential requirement. That is, the production method according to the embodiment performs polymerization by using, as a polymerization initiator, hydrogen peroxide and a reducing compound in excess of 0.5 mol% with respect to 100 mol% of the total amount of monomer components. Although it is common to the above-described production method according to one embodiment of the present invention in that it includes a step, “polymerization in the presence of a transition metal salt” is not an essential requirement, and instead The method is characterized in that it includes a step of adding a transition metal salt to the reaction system after completion of the polymerization. Also with such a configuration, when a relatively large amount of a reducing compound is used as a redox initiator in order to achieve a sufficient polymerization rate in the same manner as in the production method according to one embodiment of the present invention described above. In addition, it is possible to minimize the change in chromaticity over time after the production of the water-soluble copolymer (aqueous solution) obtained.

  In this embodiment, the specific type of transition metal salt added to the reaction system and the addition amount thereof (and preferred forms thereof) are the same as in the manufacturing method according to one embodiment of the present invention described above. Then, detailed description is abbreviate | omitted. As described later, a step of neutralizing the carboxyl group contained in the water-soluble copolymer obtained after completion of the reaction using a neutralizing agent such as sodium hydroxide may be performed. The transition metal salt may be added to the reaction system before neutralization, after neutralization, or simultaneously with neutralization. From the viewpoint of simplifying the process while also serving as moisture adjustment after neutralization, the transition metal salt may be added to the reaction system after neutralization.

(Polymer and application)
The water-soluble copolymer obtained by the production method according to an embodiment of the present invention is used as it is as a main component for various uses such as a cement dispersant and a pigment dispersant, but if necessary, it may be an alkaline substance. You may use the polymer salt obtained by adding as a main component of various uses, such as a cement dispersant. Preferred examples of such alkaline substances include inorganic substances such as hydroxides, chlorides and carbon salts of monovalent metals and divalent metals; ammonia; organic amines and the like.

  In the present invention, the pH after neutralization of the water-soluble copolymer (aqueous solution) is not particularly limited, but is preferably 3 to 12 from the viewpoint of product handling. This pH is more preferably 4 to 10, and most preferably 4.5 to 8. Examples of neutralizers for water-soluble copolymers include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkaline earth hydroxides such as calcium hydroxide and magnesium hydroxide; ammonia; monoethanolamine; And organic amines such as triethanolamine. These may be used alone or as a mixture of two or more. Preferred are alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and more preferred is sodium hydroxide.

  Neutralization may be performed in advance before supplying the monomer component to the reactor, or may be performed while polymerizing the monomer component in the reactor. The degree of neutralization from the start of polymerization to the end of polymerization is not necessarily constant as long as it is within the above range. Specifically, the degree of neutralization in the first half of polymerization and the degree of neutralization in the second half of polymerization are different. Also good.

  The molecular weight of the water-soluble copolymer obtained by the production method of the present invention is 5,000 to 10,000,000 in weight average molecular weight, preferably 7,000 to 5,000,000, more preferably 8,000 to It is 3,000,000, more preferably 9,000 to 1,000,000, particularly preferably 10,000 to 500,000, and most preferably 20,000 to 100,000.

  In the water-soluble copolymer produced by the above method, the transition metal salt is added to the reaction system after the polymerization step or after the polymerization, so that the chromaticity change of the water-soluble copolymer (aqueous solution) over time is prevented. It is thought that. According to the present invention, among the compositions containing such a polymer, there is also provided a composition having a large addition amount of transition metal salt and a high effect of preventing an increase in chromaticity. That is, according to still another aspect of the present invention, the following chemical formula 1:

Where
R ¹ , R ² and R ³ are each independently a hydrogen atom, a methyl group or — (CH ₂ ) _z COOM ² group (— (CH ₂ ) _z COOM ² is —COOM ¹ or other — (CH ₂ ) _z COOM ² may form an anhydride), z represents an integer of 0-2,
M ¹ and M ² each independently represent a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an ammonium group or an organic amine group.
A carboxylic acid monomer represented by
The following chemical formula 2:

Where
R ⁴ and R ⁵ each independently represents a hydrogen atom or a methyl group,
AO each independently represents one or more oxyalkylene groups having 2 or more carbon atoms,
n represents the number of 1 to 300 in terms of the average number of moles added of the oxyalkylene group,
x represents an integer of 0 to 2;
y represents 0 or 1,
R ⁶ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms,
A polymer composition comprising a water-soluble copolymer obtained by polymerizing a monomer component containing a polyether monomer represented as an essential component, and a solvent, a reducing compound, There is provided a polymer composition further comprising a transition metal salt of 1500 ppb or more in terms of transition metal with respect to a component derived from the polyether monomer constituting the water-soluble copolymer.

  In the production of this polymer composition, a relatively large amount of reducing compound is used as described above. Therefore, a part of the reducing compound remains in the polymer composition. Specifically, the content of the reducing compound in the polymer composition provided by still another embodiment of the present invention is preferably 0.001 to 0.1% by weight with respect to the solid content, and more Preferably it is 0.003-0.1 weight%, More preferably, it is 0.003-0.05 weight%.

  The water-soluble copolymer or polymer composition provided by the present invention can be used as a cement admixture or a dispersant.

  The cement admixture according to the present invention contains the water-soluble copolymer produced by the production method of the present invention as an essential component, but is the main component of the cement admixture as it is in the form of an aqueous solution obtained by the production method described above. It may be used as a dry powder.

  The cement admixture according to the present invention can be used for various hydraulic materials, that is, cement compositions such as cement and gypsum and other hydraulic materials. Specific examples of a hydraulic composition containing such a hydraulic material, water, and the cement admixture according to the present invention, and further containing fine aggregate (sand, etc.) and coarse aggregate (crushed stone, etc.) as necessary. Examples thereof include cement paste, mortar, concrete, plaster and the like.

  Among the hydraulic compositions, a cement composition that uses cement as a hydraulic material is the most common, and the cement composition includes the cement admixture of the present invention, cement, and water as essential components. . Such a cement composition is one of the preferred embodiments of the present invention.

  There is no limitation in particular as a cement used in the said cement composition. For example, Portland cement (ordinary, early strength, very early strength, moderate heat, sulfate-resistant and low alkali type of each), 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 exothermic blast furnace cement, belite High-concentration cement), ultra-high-strength cement, cement-based solidified material, eco-cement (city waste incineration ash, sewage sludge incineration ash as a raw material), blast furnace slag, fly ash , Cinder ash, clinker ash, Squash, 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 above cement composition, there is no particular limitation on the unit water amount per 1 m ³ , the cement usage amount and the water / cement ratio, and the unit water amount 100 to 185 kg / m ³ , the cement amount used 250 to 800 kg / m ³ , water / Cement ratio (weight ratio) = 0.1 to 0.7, preferably unit water amount 120 to 175 kg / m ³ , used cement amount 270 to 800 kg / m ³ , water / cement ratio (weight ratio) = 0.2 to 0.65 is recommended, it can be used widely from poor blend to rich blend, high-strength concrete with a large amount of unit cement and a small water / cement ratio, low water / cement ratio (weight ratio) of 0.3 or less It is effective for both ultra-high-strength concrete in the water / cement ratio region and poor-mixed concrete having a unit cement amount of 300 kg / m ³ or less. The blending ratio of the cement admixture of the present invention in the cement composition is not particularly limited, but when used for mortar, concrete or the like using hydraulic cement, the hydrophilic copolymer is converted into solid content. What is necessary is just to add the quantity of the ratio used as 0.01-5.0% of cement weight, Preferably it is 0.02-2.0%, More preferably, it is 0.05-1.0%. By this addition, various preferable effects such as reduction in unit water amount, increase in strength, and improvement in durability are brought about.

  The above cement composition is also excellent in pumpability, remarkably improves workability during construction, and has high fluidity. Therefore, ready mixed concrete, concrete for secondary concrete products (precast concrete), It is effective for concrete for centrifugal molding, concrete for vibration compaction, steam-cured concrete, shotcrete, etc. In addition, medium fluidized concrete (concrete with a slump value in the range of 22-25 cm), high fluidized concrete (slump value of 25 cm) Thus, it is also effective for mortar and concrete that require high fluidity, such as concrete having a slump flow value in the range of 50 to 70 cm, self-filling concrete, and self-leveling material.

  The cement composition can contain, for example, a cement admixture as described below. Lignin sulfonate; polyol derivative; naphthalene sulfonic acid formalin condensate; melamine sulfonic acid formalin condensate; polystyrene sulfonate; aminoaryl sulfonic acid-phenol-formaldehyde condensate as described in JP-A-1-113419, etc. As a component (a) as described in JP-A-7-267705, a copolymer of a polyalkylene glycol mono (meth) acrylic ester compound and a (meth) acrylic compound, and And / or a salt thereof, as a component (b), a copolymer of a polyalkylene glycol mono (meth) allyl ether compound and maleic anhydride and / or a hydrolyzate thereof, and / or a salt thereof (c) ) Component, polyalkylene glycol mono (meta) A cement dispersant containing a copolymer of an allyl ether compound and a maleic ester of a polyalkylene glycol compound and / or a salt thereof; as component A as described in Japanese Patent No. 2508113, (meth) A concrete admixture composed of a polyalkylene glycol ester of acrylic acid and (meth) acrylic acid (salt), a specific polyethylene glycol polypropylene glycol compound as the B component, and a specific surfactant as the C component.

  A copolymer comprising polyethylene (propylene) glycol ester of (meth) acrylic acid, (meth) allylsulfonic acid (salt), and (meth) acrylic acid (salt) as described in JP-A-1-226757 Polyethylene (propylene) glycol ester of (meth) acrylic acid as described in JP-B-5-36377, (meth) allylsulfonic acid (salt) or p- (meth) allyloxybenzenesulfonic acid (salt), A copolymer comprising (meth) acrylic acid (salt); a copolymer of polyethylene glycol mono (meth) allyl ether and maleic acid (salt) as described in JP-A-4-149056; Polyethylene glycol ester of (meth) acrylic acid as described in JP-A-5-170501, (meth) allyls Phosphonic acid (salt), (meth) acrylic acid (salt), alkanediol mono (meth) acrylate, polyalkylene glycol mono (meth) acrylate, and α, β-unsaturated monomer having an amide group in the molecule A copolymer of alkoxypolyalkylene glycol monoallyl ether and maleic anhydride as described in JP-A-5-43288, a hydrolyzate thereof, or a salt thereof; A copolymer comprising polyethylene glycol monoallyl ether, maleic acid, and a monomer copolymerizable with these monomers as described in JP-A-38380, a salt thereof, or an ester thereof.

  Polyalkylene glycol mono (meth) acrylic acid ester monomers, (meth) acrylic acid monomers, and monomers copolymerizable with these monomers as described in JP-B-59-18338 A copolymer comprising a monomer; a copolymer comprising a (meth) acrylic acid ester having a sulfonic acid group as described in JP-A-62-1119147 and a monomer copolymerizable therewith if necessary, Or a salt thereof; esterification reaction of a copolymer of an alkoxy polyalkylene glycol monoallyl ether and maleic anhydride as described in JP-A-6-271347 and a polyoxyalkylene derivative having an alkenyl group at the terminal An alkoxypolyalkylene glycol monoallyl ether and anhydrous maleate as described in JP-A-6-298555 Copolymers and, esterification reaction products of polyoxyalkylene derivative with a terminal hydroxyl group with. These cement dispersants may be used alone or in combination of two or more.

  When the cement dispersant is used, the ratio between the hydrophilic copolymer as the cement admixture of the present invention and the cement dispersant, that is, the weight ratio (wt%) in terms of solid content, The optimum ratio varies depending on the performance balance between the polymer and the cement dispersant, but is preferably 1/99 to 99/1, more preferably 5/95 to 95/5, and most preferably 10/90 to 90/10. .

Moreover, the said cement composition can contain the other well-known cement additive (material) which is illustrated to the following (1)-(20).
(1) Water-soluble polymer material: polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), unsaturated carboxylic acid polymer such as sodium salt of acrylic acid / maleic acid copolymer; methylcellulose Nonionic cellulose ethers such as ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, hydroxypropyl cellulose; alkylated or hydroxyalkylated derivatives of polysaccharides such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, etc. Hydrophobic substituents in which some or all of the hydroxyl atoms have a hydrocarbon chain having 8 to 40 carbon atoms as a partial structure, sulfonic acid groups or Polysaccharide derivatives substituted with an ionic hydrophilic substituent having a partial structure of these salts; yeast glucan, xanthan gum, β-1,3 glucans (both linear and branched chains may be used, for example Polysaccharides produced by microbial fermentation such as curdlan, paramylon, pachyman, scleroglucan, laminaran, etc.); polyacrylamide; polyvinyl alcohol; starch; starch phosphate ester; sodium alginate; gelatin; And copolymers of acrylic acid having quaternary compounds thereof.
(2) Polymer emulsion: Copolymers of various vinyl monomers such as alkyl (meth) acrylate.
(3) One or more curing retarders selected from the group consisting of oxycarboxylic acids or salts thereof, sugars and sugar alcohols: magnesium silicofluoride; phosphoric acid and salts thereof or boric acid esters; aminocarboxylic acids and salts thereof Alkaline soluble protein; humic acid; tannic acid; phenol; polyhydric alcohol such as glycerol; aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (Methylenephosphonic acid) and phosphonic acids such as alkali metal salts and alkaline earth metal salts thereof and derivatives thereof.
(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) Mineral oil-based antifoaming agent: cocoon oil, liquid paraffin, etc.
(6) Fat and oil-based antifoaming agents: animal and vegetable oils, sesame oil, castor oil, alkylene oxide adducts thereof and the like.
(7) Fatty acid-based antifoaming agent: oleic acid, stearic acid, and these alkylene oxide adducts.
(8) Fatty acid ester antifoaming agent: glycerin monoricinoleate, alkenyl succinic acid derivative, sorbitol monolaurate, sorbitol trioleate, natural wax and the like.
(9) Oxyalkylene antifoaming agents: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene (Poly) oxyalkyl ethers such as 2-ethylhexyl ether and oxyethyleneoxypropylene adducts to higher alcohols having 12 to 14 carbon atoms; (poly) oxy such as polyoxypropylene phenyl ether and polyoxyethylene nonylphenyl ether Alkylene (alkyl) aryl ethers; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl-1 − Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylenic alcohol such as tin-3-ol; (poly) oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurate, ethylene glycol distearate; polyoxyethylene (Poly) oxyalkylene sorbitan fatty acid esters such as sorbitan monolaurate and polyoxyethylene sorbitan trioleate; (poly) oxyalkylene alkyl such as sodium polyoxypropylene methyl ether sulfate and sodium polyoxyethylene dodecylphenol ether sulfate ( Aryl) ether sulfate salts; (poly) oxyethylene stearyl phosphates, etc. Sialic sharp emission alkyl phosphate esters; polyoxyethylene such as polyoxyethylene lauryl amine (poly) oxyalkylene alkyl amines; polyoxyalkylene amide.
(10) Alcohol-based antifoaming agent: octyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like.
(11) Amide antifoaming agent: acrylate polyamine and the like.
(12) Phosphate ester antifoaming agent: tributyl phosphate, sodium octyl phosphate, etc.
(13) Metal soap type antifoaming agent: aluminum stearate, calcium oleate, etc.
(14) Silicone antifoaming agent: dimethyl silicone oil, silicone paste, silicone emulsion, organically modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), fluorosilicone oil and the like.
(15) AE agent: resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, ABS (alkyl benzene sulfonic acid), LAS (linear alkyl benzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl (phenyl) ether , Polyoxyethylene alkyl (phenyl) ether sulfate or a salt thereof, polyoxyethylene alkyl (phenyl) ether phosphate or a salt thereof, protein material, alkenyl sulfosuccinic acid, α-olefin sulfonate and the like.
(16) Other surfactants: aliphatic monohydric alcohols having 6 to 30 carbon atoms in the molecule such as octadecyl alcohol and stearyl alcohol, and those having 6 to 30 carbon atoms in the molecule such as abiethyl alcohol Intramolecular such as alicyclic monohydric alcohol, dodecyl mercaptan, etc. Intramolecular such as monovalent mercaptan having 6-30 carbon atoms in the molecule, such as nonylphenol, alkylphenol having 6-30 carbon atoms in the molecule, dodecylamine, etc. 10 mol or more of an alkylene oxide such as ethylene oxide or propylene oxide was added to a carboxylic acid having 6 to 30 carbon atoms in the molecule such as an amine having 6 to 30 carbon atoms, lauric acid or stearic acid. Polyalkylene oxide derivatives having an alkyl or alkoxy group as a substituent Alkyldiphenyl ether sulfonates in which two phenyl groups having a sulfone group are ether-bonded; various anionic surfactants; various cationic surfactants such as alkylamine acetate and alkyltrimethylammonium chloride; various nonionics Surfactant; various amphoteric surfactants.
(17) Waterproofing agent: fatty acid (salt), fatty acid ester, oil and fat, silicon, paraffin, asphalt, wax and the like.
(18) Rust preventive: nitrite, phosphate, zinc oxide and the like.
(19) Crack reducing agent: polyoxyalkyl ether and the like.
(20) Expansion material: Ettlingite, coal, etc.

  Other known cement additives (materials) include cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancers, self-leveling agents, rust preventives, colorants, and antifungal agents. An agent etc. can be mentioned. These known cement additives (materials) may be used alone or in combination of two or more.

  In the above cement composition, the following (1) to (4) may be mentioned as particularly preferred embodiments for components other than cement and water.

  (1) A combination comprising two components, i.e., (i) a cement admixture according to the present invention and (ii) an oxyalkylene-based antifoaming agent. In addition, as a compounding weight ratio of the oxyalkylene type | system | group antifoamer of (ii), the range of 0.001 to 10 weight% is preferable with respect to the copolymer (A) in the cement admixture of (i).

  (2) A combination that essentially comprises two components, (i) a cement admixture according to the present invention, and (ii) a material separation reducing agent. As a material separation reducing agent, various thickeners such as nonionic cellulose ethers, a hydrophobic substituent composed of a hydrocarbon chain having 4 to 30 carbon atoms as a partial structure, and an alkylene oxide having 2 to 18 carbon atoms are added on average. A compound having a polyoxyalkylene chain having 2 to 300 moles added can be used. The blending weight ratio of the hydrophilic copolymer in the cement admixture (i) and the material separation reducing agent (ii) is preferably 10/90 to 99.99 / 0.01, 50/50 ˜99.9 / 0.1 is more preferable. The cement composition of this combination is suitable as high fluidity concrete, self-filling concrete and self-leveling material.

  (3) A combination comprising essentially two components: (i) the cement admixture of the present invention, and (ii) 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. The blending weight ratio of the hydrophilic copolymer in the cement admixture (i) and the sulfonic acid-based dispersant having a sulfonic acid group in the molecule (ii) is 5/95 to 95/5. Preferably, 10/90 to 90/10 are more preferable.

  (4) A combination comprising two components of (i) the cement admixture of the present invention and (ii) lignin sulfonate. The blending weight ratio of the hydrophilic copolymer in the cement admixture (i) and the lignin sulfonate salt of (ii) is preferably 5/95 to 95/5, and 10/90 to 90/10. Is more preferable.

  Hereinafter, examples of the present invention will be described in detail. In the following description, “%” indicates wt%, and analysis of each measurement value was performed under the following analysis conditions.

<Measurement of weight average molecular weight of copolymer>
The weight average molecular weight of the obtained copolymer was measured under the following conditions by gel permeation chromatography (GPC).

-Column used: TSK guard column SWXL, TSKgel G4000SWXL, G3000SWXL and G2000SWXL manufactured by Tosoh Corporation
Eluent: Eluent solution in which 115.6 g of sodium acetate trihydrate was dissolved in a mixed solvent of 10999 g of water and 6001 g of acetonitrile, and further adjusted to pH 6.0 with acetic acid. 100 μL as eluent solution
-Column temperature: 40 ° C
Reference material: polyethylene glycol, peak top molecular weight (Mp) 300000, 219300, 107000, 50000, 24000, 11840, 6450, 4020, 1470
・ Calibration curve order: cubic equation ・ Detector: 410 Water reflex detector made by Japan Waters ・ Analysis software: Emper software made by Japan Waters <Measurement of copolymer content (polymer pure content)>
GPC of the obtained copolymer was measured (under the above measurement conditions), and the polymer pure content was calculated from the peak area of the polymer and the peak area of the unsaturated polyalkylene glycol ether monomer using the following formula. .

Polymer purity (%) = (polymer peak area) × 100 / (polymer peak area + unsaturated polyalkylene glycol ether monomer area)
<Measurement of transition metal content>
・ Fe analysis Detection method: Spectrophotometric difference analysis by coloring of ferrozine reagent Detector: DR-2800 [HACK]
Program: 260 Ferrozinc iron ・ Cu / Mn analysis Detection method: Calibration curve method using SPEX XSTC-622B standard solution (0, 1, 5, 10, 20, 50ppb)
Detector: ICP-MS Agilent 7700s (X-lens)
The amount of Fe, Cu, and Mn in each raw material used in the following examples and comparative examples was measured under the above analysis conditions, and the results were as follows. “ND” means less than the detection limit.

・ Water (Fe 20ppb, Cu ND, Mn ND)
-Ethylene oxide adduct of 3-methyl-3-buten-1-ol (average number of moles of ethylene oxide added: 50 mol, including 6.7% by weight of polyethylene glycol) (Fe 20 ppb, Cu 2 ppb, Mn ND)
Acrylic acid (Fe 16 ppb, Cu 5 ppb, Mn 2 ppb)
・ Hydroxyethyl acrylate (Fe 4ppb, Cu 3ppb, Mn 3ppb)
2-mercaptopropionic acid (Fe 80 ppb, Cu 5 ppb, Mn 170 ppb)
・ L-ascorbic acid (Fe ND, Cu 2ppb, Mn ND)
・ 35% hydrogen peroxide (Fe 6ppb, Cu ND, Mn 1ppb)
<Measurement of chromaticity change>
The obtained copolymer (aqueous solution) was transferred to a container with a lid made of polypropylene, stored in an air atmosphere at room temperature for 10 days, and the change in chromaticity was measured as an APHA value. The measurement conditions are as follows.

Detection method: spectrophotometric analysis based on distilled water Detector: DR-2800 (manufactured by HACK)
Program: 120: Chromaticity 455nm
<Example of copolymer production>
[Comparative Example 1]
Production of copolymer 1-A In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, 91.84 g of water, an unsaturated polyalkylene glycol monomer (unsaturated As an alkylene glycol ether monomer), an ethylene oxide adduct of 3-methyl-3-buten-1-ol (“MBA-50”; average number of moles of ethylene oxide added: 50 mol, containing 6.7% by weight of polyethylene glycol) 194 .82 g and acrylic acid (“AA”; carboxylic acid monomer) 0.35 g were charged (pH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. 12.97 g of 3% hydrogen peroxide water (2.4 mol% as a hydrogen peroxide to monomer) was added. After the temperature was stabilized at 60 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 13.21 g of acrylic acid (AA) and 23.61 g of hydroxyethyl acrylate (“HEA”) were dissolved in 9.21 g of water was added 3 It dripped over time, and at the same time it started dripping the unsaturated carboxylic-acid type monomer aqueous solution, L-ascorbic acid 0.51g (0.6 mol% with respect to monomer) and 2-mercaptopropionic acid 0.91g (1. An aqueous solution prepared by dissolving 8 mol% with respect to the monomer) in 52.56 g of water was added dropwise over 3.5 hours. Thereafter, the reaction system was maintained at 60 ° C. for 1 hour to complete the polymerization reaction. And after cooling (pH 4.2, 21.4 degreeC), it neutralized to pH 6 with 30% NaOH, water was added, and solid content was adjusted to 45%. Mw of the polymer (copolymer 1-A) excluding the peak corresponding to the monomer equivalent (Mw 2200) measured by GPC was 39600, and the polymer pure content was 87.2%. Furthermore, the measurement result of the change in chromaticity was 11 on the first day, 24 on the third day, and 219 on the 10th day as an APHA value (Pt-Count).

[Example 1]
Production of Copolymer 1-B In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube, and a reflux condenser, 6.84 g of a 100 wt ppm aqueous solution of molle salt as a transition metal salt (described later) MBA-50, transition metal (Fe) 500 weight ppb), water 85.0 g, polyalkylene glycol ether compound (polyether monomer) as 3-methyl-3-buten-1-ol 194.82 g of ethylene oxide adduct (“MBA-50”; average number of moles of ethylene oxide added 50 mol, including 6.7% by weight of polyethylene glycol) and 0.35 g of acrylic acid (“AA”; carboxylic acid monomer) were charged. (PH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere, followed by 12.97 g of 3% hydrogen peroxide (peroxide water) 2.4 mol% to monomer) was added as an element. After the temperature was stabilized at 60 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 13.21 g (AA) of acrylic acid and 23.61 g of hydroxyethyl acrylate (“HEA”) were dissolved in 9.21 g of water was added 3 At the same time as the dropwise addition of the unsaturated carboxylic acid monomer aqueous solution, the addition of 0.51 g of L-ascorbic acid (0.6 mol% to monomer) and 0.91 g of 2-mercaptopropionic acid (2. 4 mol% to monomer) in 52.56 g of water was added dropwise over 3.5 hours. Thereafter, the reaction system was maintained at 60 ° C. for 1 hour to complete the polymerization reaction. And after cooling (pH 4.2, 21.4 degreeC), it neutralized to pH 6 with 30% NaOH, water was added, and solid content was adjusted to 45%. The polymer (copolymer 1-B) excluding the peak corresponding to the monomer equivalent (Mw 2200), as measured by GPC, had a Mw of 45,500 and a polymer pure content of 89.2%. Furthermore, the measurement result of the chromaticity change was APHA value (Pt-Count) of 20 on the first day, 14 on the third day, and 24 on the 10th day.

[Comparative Example 2]
Production of copolymer 2-A 96.3 g of water, polyalkylene glycol ether compound (polyether monomer) in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube and reflux condenser As an ethylene oxide adduct of 3-methyl-3-buten-1-ol (“MBA-50”; average number of moles of ethylene oxide added: 50 mol, containing 6.7% by weight of polyethylene glycol), 204.4 g of acrylic acid (“ AA "; carboxylic acid monomer) 0.37 g was charged (pH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 65 ° C in a nitrogen atmosphere. .2 g (4.0 mol% as hydrogen peroxide to monomer) was charged. After the temperature was stabilized at 65 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 27.3 g of acrylic acid (AA) was dissolved in 6.81 g of water was dropped over 3 hours, At the same time as the body aqueous solution was dripped, L-ascorbic acid 0.83 g (1.0 mol% to monomer) and 2-mercaptopropionic acid 1.00 g (2.0 mol% to monomer) were added to 46.4 g of water. The dissolved aqueous solution was added dropwise over 3.5 hours. Thereafter, the reaction system was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. And after cooling (pH 4.2, 20.0 degreeC), it neutralized to pH 6 with 30% NaOH, water was added, and solid content was adjusted to 45%. The polymer (copolymer 2-A) excluding the peak corresponding to the monomer equivalent (Mw 2200), as measured by GPC, had a Mw of 35,800 and a pure polymer content of 86.0%. Furthermore, the measurement result of the chromaticity change was APHA value (Pt-Count) as 6 on the first day, 101 on the third day, and 315 on the 10th day.

[Example 2]
Production of Copolymer 2-B In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, 5.00 g of a 500 wt ppm aqueous solution of iron (III) nitrate as a transition metal salt. (2000 weight ppb in terms of transition metal (Fe) relative to MBA-50 described later), 91.3 g of water, and polymethylene glycol ether compound (polyether monomer) as 3-methyl-3-butene-1 -Ethylene oxide adduct ("MBA-50"; average number of moles of ethylene oxide added 50 moles, containing 6.7% by weight of polyethylene glycol) 204.4 g, acrylic acid ("AA"; carboxylic acid monomer) 0. 37 g was charged (pH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 65 ° C. in a nitrogen atmosphere. 4.0 mol% to monomer) was added as hydrogen oxide. After the temperature was stabilized at 65 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 27.3 g of acrylic acid (AA) was dissolved in 6.81 g of water was dropped over 3 hours, At the same time as the body aqueous solution was dripped, 0.83 g (1.0 mol% to monomer) of L-ascorbic acid and 1.51 g of 2-mercaptopropionic acid (3.0 mol% to monomer) were added to 46.4 g of water. The dissolved aqueous solution was added dropwise over 3.5 hours. Thereafter, the reaction system was maintained at 65 ° C. for 1 hour to complete the polymerization reaction. And after cooling (pH 4.2, 20.0 degreeC), it neutralized to pH 6 with 30% NaOH, water was added, and solid content was adjusted to 45%. The polymer (copolymer 2-B) excluding the peak corresponding to the monomer equivalent (Mw 2200) measured by GPC had a Mw of 34800 and a polymer pure content of 85.6%. Furthermore, the measurement result of the chromaticity change was APHA value (Pt-Count) of 26 on the first day, 103 on the third day, and 191 on the tenth day.

[Comparative Example 3]
Production of Copolymer 3-A In a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, water 124.2 g, polyalkylene glycol ether compound (polyether monomer) As an ethylene oxide adduct of 3-methyl-3-buten-1-ol (“MBA-50”; average number of moles of ethylene oxide added: 50 mol, containing 6.7% by weight of polyethylene glycol), acrylic acid (“ AA "; carboxylic acid monomer) 0.38 g was charged (pH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 70 ° C. in a nitrogen atmosphere. .01 g (6.0 mol% as hydrogen peroxide to monomer) was charged. After the temperature was stabilized at 70 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 8.96 g of acrylic acid (AA) was dissolved in 20.9 g of water was dropped over 5 hours, At the same time as the dropping of the body aqueous solution, an aqueous solution prepared by dissolving 0.58 g of L-ascorbic acid (1.5 mol% to monomer) in 21.0 g of water was added dropwise over 5 hours and 10 minutes. Subsequently, the reaction system was maintained at 70 ° C. for 20 minutes to complete the polymerization reaction. And after cooling (pH 4.2, 20.0 degreeC), it neutralized to pH 6 with 30% NaOH, water was added, and solid content was adjusted to 45%. The polymer (copolymer 3-A) excluding the peak corresponding to the monomer equivalent (Mw 2200) measured by GPC had a Mw of 54,000 and a polymer pure content of 77.5%. Furthermore, the measurement result of the chromaticity change was APHA value (Pt-Count) of 16 on the first day, 98 on the third day, and 280 on the 10th day.

[Example 3-1]
Production of copolymer 3-B In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube, and a reflux condenser, 14.7 g of a 100 wt ppm aqueous solution of molle salt as a transition metal salt (described later) MBA-50, transition metal (Fe) 1000 weight ppb), water 109.5 g, polyalkylene glycol ether compound (polyether monomer) as 3-methyl-3-buten-1-ol Charge 209.4 g of ethylene oxide adduct (“MBA-50”; average number of moles of ethylene oxide added 50 mol, polyethylene glycol 6.7 wt%) and 0.38 g of acrylic acid (“AA”; carboxylic acid monomer) (PH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 70 ° C. in a nitrogen atmosphere, followed by 15.01 g of 2% hydrogen peroxide (peroxidation) 6.0 mol% to monomer) was added as hydrogen. After the temperature was stabilized at 70 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 8.96 g of acrylic acid (AA) was dissolved in 20.9 g of water was dropped over 5 hours, At the same time as the dropping of the body aqueous solution, an aqueous solution prepared by dissolving 0.58 g of L-ascorbic acid (1.5 mol% to monomer) in 21.0 g of water was added dropwise over 5 hours and 10 minutes. Subsequently, the reaction system was maintained at 70 ° C. for 20 minutes to complete the polymerization reaction. And after cooling (pH 4.0, 17.5 degreeC), it neutralized to pH 6 with 30% NaOH, water was added, and solid content was adjusted to 45%. Mw of the polymer (copolymer 3-B) excluding the peak corresponding to the monomer equivalent (Mw 2200) measured by GPC was 44000, and the polymer pure content was 80.3%. Furthermore, the measurement result of the chromaticity change was APHA value (Pt-Count) of 15 on the first day, 13 on the third day, and 18 on the 10th day.

[Example 3-2]
Production of Copolymer 3-C In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube, and a reflux condenser, 29.4 g of a 100 wt ppm aqueous solution of molle salt as a transition metal salt (described later) As a transition metal (Fe) in terms of MBA-50, 2000 weight ppb), water 94.8 g, polyalkylene glycol ether compound (polyether monomer), 3-methyl-3-buten-1-ol Charge 209.4 g of ethylene oxide adduct (“MBA-50”; average number of moles of ethylene oxide added 50 mol, polyethylene glycol 6.7 wt%) and 0.38 g of acrylic acid (“AA”; carboxylic acid monomer) (PH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 70 ° C. in a nitrogen atmosphere, and then 15.01 g of 2% hydrogen peroxide (peroxide water) 6.0 mol% to monomer) was added. After the temperature was stabilized at 70 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 8.96 g of acrylic acid (AA) was dissolved in 20.9 g of water was dropped over 5 hours, At the same time as the dropping of the body aqueous solution, an aqueous solution prepared by dissolving 0.58 g of L-ascorbic acid (1.5 mol% to monomer) in 21.0 g of water was added dropwise over 5 hours and 10 minutes. Subsequently, the reaction system was maintained at 70 ° C. for 20 minutes to complete the polymerization reaction. And after cooling (pH 4.1, 20.5 degreeC), it neutralized to pH 6 with 30% NaOH, water was added, and solid content was adjusted to 45%. The polymer (copolymer 3-C) excluding the peak corresponding to the monomer equivalent (Mw 2200) measured by GPC had a Mw of 44000 and a polymer pure content of 80.6%. Further, the measurement result of chromaticity change was APHA value (Pt-Count) as 18 on the first day, 15 on the third day, and 14 on the 10th day.

[Example 3-3]
Production of copolymer 3-D In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube, and a reflux condenser, 7.3 g of a 100 wt ppm aqueous solution of a mole salt as a transition metal salt (described later) MBA-50 as a transition metal (Fe) 500 wt ppb), 70% p-toluenesulfonic acid aqueous solution 1.1 g, water 116.8 g, polyalkylene glycol ether compound (polyether monomer) 209.4 g of ethylene oxide adduct of 3-methyl-3-buten-1-ol (“MBA-50”; average number of moles of ethylene oxide added: 50 mol, containing 6.7% by weight of polyethylene glycol), acrylic acid (“AA”) Carboxylic acid monomer) (0.38 g) (pH 2.9), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 65 ° C. under a nitrogen atmosphere Thereafter, 15.01 g of 2% aqueous hydrogen peroxide (6.0 mol% as a hydrogen peroxide to monomer) was added. After the temperature is stabilized at 65 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 8.96 g of acrylic acid (AA) is dissolved in 20.9 g of water is added dropwise over 5 hours, and the amount of unsaturated carboxylic acid single system At the same time as the dropping of the body aqueous solution, an aqueous solution prepared by dissolving 0.58 g of L-ascorbic acid (1.5 mol% to monomer) in 21.0 g of water was added dropwise over 5 hours and 10 minutes. Subsequently, the reaction system was maintained at 65 ° C. for 20 minutes to complete the polymerization reaction. And after cooling (pH 2.9, 20.0 degreeC), it neutralized to pH 6 with 30% NaOH, water was added, and solid content was adjusted to 45%. Mw of the polymer (copolymer 3-D) excluding the peak corresponding to the monomer equivalent (Mw 2200) measured by GPC was 42000, and the polymer pure content was 82.9%. Further, the measurement result of chromaticity change was APHA value (Pt-Count) as 18 on the first day, 19 on the third day, and 25 on the 10th day.

[Comparative Example 4]
Production of copolymer 4-A In a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, water 96.3 g, polyalkylene glycol ether compound (polyether monomer) As an ethylene oxide adduct of 3-methyl-3-buten-1-ol (“MBA-50”; average number of moles of ethylene oxide added: 50 mol, containing 6.7% by weight of polyethylene glycol), 204.4 g of acrylic acid (“ AA "; carboxylic acid monomer) 0.37 g was charged (pH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. .65 g (2.4 mol% as hydrogen peroxide to monomer) was charged. After the temperature was stabilized at 60 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 27.3 g of acrylic acid (AA) was dissolved in 6.81 g of water was dropped over 3 hours, At the same time as the body aqueous solution was added dropwise, 0.50 g of L-ascorbic acid (0.6 mol% to monomer) and 1.00 g of 2-mercaptopropionic acid (2.0 mol% to monomer) were added to 46.4 g of water. The dissolved aqueous solution was added dropwise over 3.5 hours. Thereafter, the reaction system was maintained at 60 ° C. for 1 hour to complete the polymerization reaction. And after cooling (pH 4.2, 20.0 degreeC), it neutralized to pH 6 with 30% NaOH, water was added, and solid content was adjusted to 45%. Mw of the polymer (copolymer 4-A) excluding the peak corresponding to the monomer equivalent (Mw 2200) measured by GPC was 35800, and the polymer pure content was 86.0%. Furthermore, the measurement result of the chromaticity change was APHA value (Pt-Count), with 2 on the first day, 45 on the third day, and 99 on the 10th day.

[Example 4]
Production of copolymer 4-B In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, 96.3 g of water, a polyalkylene glycol ether compound (polyether monomer) As an ethylene oxide adduct of 3-methyl-3-buten-1-ol (“MBA-50”; average number of moles of ethylene oxide added: 50 mol, containing 6.7% by weight of polyethylene glycol), 204.4 g of acrylic acid (“ AA "; carboxylic acid monomer) 0.37 g was charged (pH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. .65 g (2.4 mol% as hydrogen peroxide to monomer) was charged. After the temperature was stabilized at 60 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 27.3 g of acrylic acid (AA) was dissolved in 6.81 g of water was dropped over 3 hours, At the same time as the body aqueous solution was added dropwise, 0.50 g of L-ascorbic acid (0.6 mol% to monomer) and 1.00 g of 2-mercaptopropionic acid (2.0 mol% to monomer) were added to 46.4 g of water. The dissolved aqueous solution was added dropwise over 3.5 hours. Thereafter, the reaction system was maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Then, after cooling (pH 4.2, 20.0 ° C.), the solution is neutralized with 30% NaOH to pH 6, and 7.33 g of a 100 wt ppm aqueous solution of molle salt, which is a transition metal salt (transition with respect to MBA-50 described above) Metal (Fe) 500 wt ppb) was added, and water was added to adjust the solid content to 45%. The monomer composition in the obtained copolymer was IPN-50: AA (in terms of sodium acrylate) = 85: 15 by weight ratio. Further, the polymer (copolymer 4-B) excluding the peak corresponding to the monomer equivalent (Mw 2200) measured by GPC had a Mw of 35,800 and a pure polymer content of 86.0%. Furthermore, the measurement result of chromaticity change was APHA value (Pt-Count) as 11 on the first day, 15 on the third day, and 44 on the 10th day.

[Comparative Example 5-1]
Production of copolymer 5-A In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, 114.8 g of water, a polyalkylene glycol ether compound (polyether monomer) As an ethylene oxide adduct of 3-methyl-3-buten-1-ol ("MBA-50"; average number of moles of ethylene oxide added: 50 mol, containing 6.7% by weight of polyethylene glycol), 226.3 g of acrylic acid (" AA "; carboxylic acid monomer) 0.41 g was charged (pH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 58 ° C. in a nitrogen atmosphere. .3 g (2.0 mol% as hydrogen peroxide to monomer) was charged. After the temperature was stabilized at 58 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 15.7 g of acrylic acid (AA) was dissolved in 10.5 g of water was added dropwise over 3 hours to obtain an unsaturated carboxylic acid monomer. At the same time as the body aqueous solution was added dropwise, 0.17 g (0.3 mol% to monomer) of L-ascorbic acid and 0.46 g (1.35 mol% to monomer) of 2-mercaptopropionic acid were added to 24.4 g of water. The dissolved aqueous solution was added dropwise over 3.5 hours. Subsequently, the reaction system was maintained at 58 ° C. for 3 hours to complete the polymerization reaction. And after cooling (pH 4.2, 20.0 degreeC), it neutralized to pH 6 with 49% NaOH, water was added, and solid content was adjusted to 45%. Mw of the polymer (copolymer 5-A) excluding the peak corresponding to the monomer equivalent (Mw 2200), measured by GPC, was 35000, and the polymer pure content was 74.7%. Furthermore, the measurement result of the change in chromaticity was APHA value (Pt-Count) of 2 on the first day, 24 on the third day, and 23 on the 10th day.

[Comparative Example 5-2]
Production of copolymer 5-B In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube, and a reflux condenser, 5.63 g of a 100 wt ppm aqueous solution of molle salt as a transition metal salt (described later) Transition metal (Fe) 500 wt ppb) was added to MBA-50, and 114.8 g of water and 3-methyl-3-butene-1 were obtained as a polyalkylene glycol ether compound (polyether monomer). -Ethylene oxide adduct of all ("MBA-50"; average number of moles of ethylene oxide added 50 moles, containing 6.7% by weight of polyethylene glycol) 226.3 g, acrylic acid ("AA"; carboxylic acid monomer) 0. 41 g was charged (pH 4.5), the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 58 ° C. in a nitrogen atmosphere. As the hydrogen oxide, 2.0 mol% to monomer) was added. After the temperature was stabilized at 58 ° C., an unsaturated carboxylic acid monomer aqueous solution in which 15.7 g of acrylic acid (AA) was dissolved in 10.5 g of water was added dropwise over 3 hours to obtain an unsaturated carboxylic acid monomer. At the same time as the body aqueous solution was dripped, 0.17 g of L-ascorbic acid (0.3 mol% to monomer) and 0.49 g of 2-mercaptopropionic acid (1.4 mol% to monomer) were added to 24.4 g of water. The dissolved aqueous solution was added dropwise over 3.5 hours. Subsequently, the reaction system was maintained at 58 ° C. for 3 hours to complete the polymerization reaction. And after cooling (pH 4.2, 20.0 degreeC), it neutralized to 49 with 49% NaOH, and also water was added, and solid content was adjusted to 45%. Mw of the polymer (copolymer 5-B) excluding the peak corresponding to the monomer equivalent (Mw 2200) measured by GPC was 34700, and the polymer pure content was 76.5%. Furthermore, the measurement result of the chromaticity change was APHA value (Pt-Count) of 3 on the first day, 15 on the third day, and 20 on the 10th day.

  From the above results, the copolymers (aqueous solutions) of Example 1, Example 2, and Examples 3-1 to 3-3 produced by the production method according to the present invention are compatible even on the 10th day after synthesis. It can be seen that the increase in chromaticity is remarkably suppressed as compared with the comparative copolymer (aqueous solution). Further, in Example 4 in which the transition metal salt was added to the aqueous solution after the production of the copolymer, the increase in chromaticity on the 10th day after the synthesis was significantly suppressed as compared with the corresponding Comparative Example 4. Recognize.

<Concrete test 1>
Concrete test 1 was performed using the copolymer (aqueous solution) obtained in Comparative Example 3 and Examples 3-1 to 3-3 as a cement admixture. As cement, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.), Oikawa production sand (FM = 2.45) as fine aggregate, and Ome hard sandstone (5-10 mm / 10-15 mm / 15-20 mm = 3) as coarse aggregate. Used by mixing at / 3/4). The concrete mixing conditions were as shown in Table 1 below. Abbreviations in Table 1 are as follows.

W / C (%): weight ratio of water (W) to cement (C) (wt%)
s / a (%): Volume ratio of fine aggregate (%)

  After adding stone, sand (half amount), cement, sand (half amount) in this order into a 100 L pan-type mixer in the order shown in Table 1 and performing kneading for 10 seconds, Comparative Example 3 and Example 3 A predetermined amount of water (concentration of polycarboxylic acid copolymer with respect to cement: 0.17% by weight) containing each of the copolymers (aqueous solutions) obtained in 3-1 to 3-3 was charged for 90 seconds. Kneaded.

  The kneaded fresh concrete was discharged to a ship, and after two reciprocations, the slump flow value was measured as an initial fluidity evaluation of the concrete. The measurement was performed according to Japanese Industrial Standard (JIS A1150). The results are shown in Table 2 below.

  From the results shown in Table 2, the copolymer obtained by the production method of the present invention exhibits a slump flow value at least equivalent to that of a copolymer produced without using a transition metal salt. I understand that. In Example 3-1, in which the transition metal salt (Mole salt) was added in such an amount that the amount of the transition metal (Fe) was 1000 ppb (vs. IPN 50 weight ratio), the slump flow value was higher than that of Comparative Example 3. You can also see that it is achieved.

<Concrete test 2>
Concrete test 2 was performed using the copolymer (aqueous solution) obtained in Comparative Example 4 and Example 4 as a cement admixture. As cement, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.), Oikawa production sand (FM = 2.61) as fine aggregate, and Ome hard sandstone (5-10 mm / 10-15 mm / 15-20 mm = 3) as coarse aggregate. Used by mixing at / 3/4). The concrete mixing conditions were as shown in Table 3 below. The abbreviations in Table 3 are the same as in Table 1 above.

  After adding stone, sand (half amount), cement, sand (half amount) in this order into the 100 L pan-type mixer in the order shown in Table 3 and performing kneading for 10 seconds, Comparative Example 4 and Example 4 A predetermined amount of water (concentration of polycarboxylic acid copolymer with respect to cement: 0.16% by weight) containing an aqueous solution of each copolymer obtained in the above was added and kneaded for 90 seconds.

  The kneaded fresh concrete was discharged to a ship, and after two reciprocations, the slump flow value was measured as an initial fluidity evaluation of the concrete. The measurement was performed according to Japanese Industrial Standard (JIS A1150). The results are shown in Table 4 below.

  From the results shown in Table 4, in Example 4 in which the transition metal salt was added to the copolymer (aqueous solution) obtained after the completion of the polymerization reaction, which is an embodiment of the present invention, comparison was not performed. It can be seen that higher slump flow values are achieved for Example 4.

Claims (9)

The following chemical formula 1:

Where
R ¹ , R ² and R ³ are each independently a hydrogen atom, a methyl group or — (CH ₂ ) _z COOM ² group (— (CH ₂ ) _z COOM ² is —COOM ¹ or other — (CH ₂ ) _z COOM ² may form an anhydride), z represents an integer of 0-2,
M ¹ and M ² each independently represent a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an ammonium group or an organic amine group.
A carboxylic acid monomer represented by
The following chemical formula 2:

Where
R ⁴ and R ⁵ each independently represents a hydrogen atom or a methyl group,
AO each independently represents one or more oxyalkylene groups having 2 or more carbon atoms,
n represents the number of 1 to 300 in terms of the average number of moles added of the oxyalkylene group,
x represents an integer of 0 to 2;
y represents 0 or 1,
R ⁶ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms,
A method for producing a water-soluble copolymer comprising polymerizing a monomer component containing a polyether monomer represented by the formula (1) as an essential component using a polymerization initiator,
Polymerization is carried out in the presence of a transition metal salt using hydrogen peroxide and a reducing compound of more than 0.5 mol% based on 100 mol% of the total amount of the monomer components as the polymerization initiator. A process for producing a water-soluble copolymer, characterized in that   The water-soluble (meth) acrylic acid (salt) according to claim 1, wherein the reducing compound is one or more selected from the group consisting of L-ascorbic acid, erythorbic acid and salts or esters thereof. ) A method for producing a polymer.   The water-soluble (meth) acrylic acid (salt) -based heavy according to claim 1 or 2, wherein the transition metal salt is one or more selected from the group consisting of an iron salt, a copper salt, and a manganese salt. Manufacturing method of coalescence.   The method for producing a water-soluble (meth) acrylic acid (salt) polymer according to any one of claims 1 to 3, wherein the transition metal salt is present in a reaction system before the start of dropping of the reducing compound. .   The method for producing a water-soluble (meth) acrylic acid (salt) polymer according to any one of claims 1 to 3, wherein the transition metal salt is added to the reaction system after the dropping of the reducing compound is started. The following chemical formula 1:

Where
R ¹ , R ² and R ³ are each independently a hydrogen atom, a methyl group or — (CH ₂ ) _z COOM ² group (— (CH ₂ ) _z COOM ² is —COOM ¹ or other — (CH ₂ ) _z COOM ² may form an anhydride), z represents an integer of 0-2,
M ¹ and M ² each independently represent a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an ammonium group or an organic amine group.
A carboxylic acid monomer represented by
The following chemical formula 2:

Where
R ⁴ and R ⁵ each independently represents a hydrogen atom or a methyl group,
AO each independently represents one or more oxyalkylene groups having 2 or more carbon atoms,
n represents the number of 1 to 300 in terms of the average number of moles added of the oxyalkylene group,
x represents an integer of 0 to 2;
y represents 0 or 1,
R ⁶ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms,
A method for producing a water-soluble copolymer comprising polymerizing a monomer component containing a polyether monomer represented by the formula (1) as an essential component using a polymerization initiator,
As the polymerization initiator, polymerization is performed using hydrogen peroxide and a reducing compound in excess of 0.5 mol% with respect to 100 mol% of the total amount of the monomers (a), (b) and (c). A process of performing;
Adding a transition metal salt to the reaction system after completion of the polymerization;
A process for producing a water-soluble copolymer, comprising:   The water-soluble copolymer for cement admixtures manufactured by the manufacturing method of any one of Claims 1-6. The following chemical formula 1:

Where
R ¹ , R ² and R ³ are each independently a hydrogen atom, a methyl group or — (CH ₂ ) _z COOM ² group (— (CH ₂ ) _z COOM ² is —COOM ¹ or other — (CH ₂ ) _z COOM ² may form an anhydride), z represents an integer of 0-2,
M ¹ and M ² each independently represent a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an ammonium group or an organic amine group.
A carboxylic acid monomer represented by
The following chemical formula 2:

Where
R ⁴ and R ⁵ each independently represents a hydrogen atom or a methyl group,
AO each independently represents one or more oxyalkylene groups having 2 or more carbon atoms,
n represents the number of 1 to 300 in terms of the average number of moles added of the oxyalkylene group,
x represents an integer of 0 to 2;
y represents 0 or 1,
R ⁶ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms,
A water-soluble copolymer obtained by polymerizing a monomer component containing a polyether monomer represented by the following as an essential component, and a solvent,
A polymer composition further comprising a reducing compound and a transition metal salt of 1500 ppb or more in terms of transition metal with respect to the component derived from the polyether monomer constituting the water-soluble copolymer.   The polymer composition according to claim 8, wherein the content of the reducing compound is 0.001 to 0.1% by weight with respect to the solid content.