JP2008106238A - Method for manufacturing copolymer having polyalkylene glycol chain - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a copolymer having a polyalkylene glycol chain having an improved dispersibility of inorganic substances and providing a good condition to mortor, etc, and to provide a method for producing an unsaturated monomer which may be a raw material of such copolymer. <P>SOLUTION: According to the method for manufacturing, 10 mass% or more of unsaturated monomers containing 1-20 mass% of polyalkylene glycol at least as a part of the unsaturated monomers based on a total amount of the monomer components, is used when the copolymer having the polyalkylene glycol chain is produced by polymerizing monomer components containing an unsaturated monomer expressed by formula (1) and an unsaturated monocarboxylic acid monomer. An unsaturated alcohol containing 100-10,000 ppm of water at least as a part of the unsaturated alcohol is used when the unsaturated monomer expressed by the formula (1) is produced by adding alkylene oxide to the unsaturated alcohol. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a copolymer having a polyalkylene glycol chain, and a method for producing an unsaturated polyalkylene glycol ether monomer that gives the copolymer.

  In the recent concrete industry, improvement in durability and strength of concrete buildings is strongly demanded, and reduction of unit water volume is an important issue. In particular, polycarboxylic acid-based cement dispersants have many proposals because they exhibit higher water reduction performance than conventional naphthalene-based cement dispersants.

For example, Patent Document 1 proposes a copolymer obtained by using an unsaturated carboxylic acid monomer and an unsaturated alcohol monomer in a specific ratio. The performance was inadequate. Further, Patent Document 2 proposes a copolymer obtained by using an unsaturated polyalkylene glycol ether monomer and a maleic acid monomer in a specific ratio. Due to problems such as copolymerization of the body, the amount of addition necessary to obtain sufficient dispersion performance is large, and there is currently no product that can satisfy the dispersion performance particularly in the high water reduction rate region. .
Japanese Examined Patent Publication No. 4-68323 JP-A-10-236858 Japanese Patent No. 3683176

  As a result of intensive studies aimed at providing a copolymer for a cement admixture exhibiting high dispersibility with a small addition amount and exhibiting excellent dispersion performance even in a high water reduction rate region, the present applicant has limited the chain length. Copolymers obtained by polymerizing specific unsaturated polyalkylene glycol ether monomers and unsaturated monocarboxylic acid monomers under specific conditions exhibit high dispersion performance with a small addition amount We have found that this is possible and have already obtained a patent (see Patent Document 3).

  Under the circumstances described above, the problem to be solved by the present invention is a copolymer having a polyalkylene glycol chain that has further improved inorganic dispersion performance and gives a good state to a cement composition such as mortar and concrete. And a method for producing an unsaturated monomer as a raw material for such a copolymer.

  As a result of various studies, the inventors of the present invention, when producing an unsaturated polyalkylene glycol ether monomer, include unsaturated aldehyde as an impurity in the unsaturated alcohol as a raw material. When an alkylene oxide is added, it causes modification to cause coloring, and the presence of water contained in the unsaturated alcohol causes thermal degradation of the unsaturated polyalkylene glycol ether monomer, resulting in polyalkylene glycol. In particular, the presence of impurities such as polyalkylene glycols and diene compounds is surprising when the finally obtained copolymer is used as a cement admixture. Further, the present invention has found that the improved inorganic dispersion performance and mortar provide a good state, and the present invention. Completed.

  That is, the present invention provides the following formula (1):

[Wherein, R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and AO represents 2 carbon atoms. -18 represents an oxyalkylene group, n represents the average number of moles added of the oxyalkylene group, represents a number of 1 to 300, and when n is 2 or more, a plurality of AOs are the same or different. X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1.]
A method for producing a copolymer having a polyalkylene glycol chain by polymerizing a monomer component containing an unsaturated polyalkylene glycol monomer and an unsaturated monocarboxylic acid monomer represented by The unsaturated polyalkylene glycol monomer containing 1 to 20% by mass of polyalkylene glycol as at least a part of the unsaturated polyalkylene glycol monomer is added to the total amount of the monomer components. On the other hand, the manufacturing method characterized by using 10 mass% or more is provided. In this production method, an unsaturated polyalkylene glycol monomer containing 100 to 10,000 ppm of isoprene on a mass basis is preferably used as at least part of the unsaturated polyalkylene glycol monomer. The unsaturated monocarboxylic acid monomer is preferably a monomer containing a (meth) acrylic acid monomer, and the (meth) acrylic monomer in the (meth) acrylic monomer. The acrylic acid dimer content is preferably 5% by mass or less with respect to the (meth) acrylic acid monomer. The copolymer is preferably a cement admixture copolymer.
The present invention also provides the following formula (2):

[Wherein R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1]
By adding an alkylene oxide to the unsaturated alcohol represented by the following formula (1):

[Wherein, R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and AO represents 2 carbon atoms. -18 represents an oxyalkylene group, n represents the average number of moles added of the oxyalkylene group, represents a number of 1 to 300, and when n is 2 or more, a plurality of AOs are the same or different. X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1.]
A method for producing an unsaturated polyalkylene glycol ether monomer represented by the formula (1), wherein an unsaturated alcohol containing 100 to 10,000 ppm of water on a mass basis is used as at least a part of the unsaturated alcohol. Provided are a production method characterized by this, and an unsaturated polyalkylene glycol ether monomer obtained by this production method.
Furthermore, the present invention provides the following formula (2):

[Wherein R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1]
By adding an alkylene oxide to the unsaturated alcohol represented by the following formula (1):

[Wherein, R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and AO represents 2 carbon atoms. -18 represents an oxyalkylene group, n represents the average number of moles added of the oxyalkylene group, represents a number of 1 to 300, and when n is 2 or more, a plurality of AOs are the same or different. X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1.]
The unsaturated polyalkylene glycol ether monomer represented by the formula (1) is produced, and the monomer component containing the unsaturated polyalkylene glycol ether monomer and the unsaturated monocarboxylic acid monomer is polymerized. To produce a copolymer having a polyalkylene glycol chain, wherein as the at least part of the unsaturated alcohol, an unsaturated alcohol containing 100 to 10,000 ppm of water on a mass basis is used, and the unsaturated alcohol is used. As at least a part of the saturated polyalkylene glycol ether monomer, an unsaturated polyalkylene glycol ether monomer containing 1 to 20% by mass of polyalkylene glycol, with respect to the total amount of the monomer components, A production method characterized by using 10% by mass or more is provided. The copolymer is preferably a cement admixture copolymer.

  According to the present invention, in producing a copolymer having a polyalkylene glycol chain, an unsaturated compound containing a predetermined amount of polyalkylene glycol as at least a part of the unsaturated polyalkylene glycol ether monomer as a raw material. Since a polyalkylene glycol ether monomer is used, the copolymer obtained also contains polyalkylene glycol. Therefore, when such a copolymer is used as a cement admixture, the dispersibility of the inorganic substance is improved and the mortar state is improved. In addition, in producing a copolymer using an unsaturated polyalkylene glycol ether monomer containing a predetermined amount of isoprene as at least a part of the raw material unsaturated polyalkylene glycol ether monomer, This isoprene acts as a crosslinking agent, increasing the molecular weight of the resulting copolymer. Therefore, the state of mortar using such a copolymer and the dispersion retention of cement are improved. Further, in the production of the unsaturated polyalkylene glycol ether monomer, an unsaturated alcohol containing a predetermined amount of water is used as at least a part of the unsaturated alcohol as a raw material. Reaction produces polyalkylene glycol. Therefore, the unsaturated polyalkylene glycol ether monomer obtained contains polyalkylene glycol. Therefore, as described above, the mortar state using the copolymer obtained from such an unsaturated polyalkylene glycol ether monomer is improved.

≪Method for producing copolymer≫
The method for producing a copolymer according to the present invention comprises the following formula (1):

[Wherein, R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and AO represents 2 carbon atoms. -18 represents an oxyalkylene group, n represents the average number of moles added of the oxyalkylene group, represents a number of 1 to 300, and when n is 2 or more, a plurality of AOs are the same or different. X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1.]
A method for producing a copolymer having a polyalkylene glycol chain by polymerizing a monomer component containing an unsaturated polyalkylene glycol monomer and an unsaturated monocarboxylic acid monomer represented by The unsaturated polyalkylene glycol monomer containing 1 to 20% by mass of polyalkylene glycol as at least a part of the unsaturated polyalkylene glycol monomer is added to the total amount of the monomer components. On the other hand, it is characterized by using 10% by mass or more.

  In the production method as described above, an unsaturated polyalkylene glycol-based monomer containing 100 to 10,000 ppm of isoprene on a mass basis is preferably used as at least a part of the unsaturated polyalkylene glycol-based monomer. .

  The unsaturated monocarboxylic acid monomer is preferably a monomer containing a (meth) acrylic acid monomer, and the (meth) acrylic monomer in the (meth) acrylic monomer. The acrylic acid dimer content is preferably 5% by mass or less with respect to the (meth) acrylic acid monomer.

  Hereinafter, the method for producing a copolymer having a polyalkylene glycol chain according to the present invention will be described in detail. The production method of the present invention is generally used as a method for producing a copolymer having a polyalkylene glycol chain (hereinafter sometimes referred to as “copolymer”), but the method is not limited thereto. Absent. For example, instead of an unsaturated polyalkylene glycol ether monomer, a monomer before addition of alkylene oxide or polyalkylene glycol, that is, 3-methyl-3-buten-1-ol, 3-methyl-2 -Unsaturated alcohol such as buten-1-ol and 2-methyl-3-buten-2-ol was used and copolymerized with an unsaturated monocarboxylic acid monomer in the presence of a polymerization initiator. After (if necessary, other monomers copolymerizable with these monomers may be further copolymerized), an average of 1 to 300 moles of alkylene oxide is added, or an average number of moles added is 1 The copolymer of the present invention can also be obtained by a method of reacting ~ 300 alkoxy polyalkylene glycol.

  The method for producing a copolymer according to the present invention comprises an unsaturated polyalkylene glycol ether monomer (hereinafter sometimes referred to as “monomer (a)”) and an unsaturated monocarboxylic acid monomer (hereinafter referred to as “monomer (a)”). Polymerization of the monomer component containing the monomer (b) ”. This monomer component may further contain another monomer (c).

  Examples of the monomer (a) include 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, 2-methyl-3-buten-2-ol, and 2-methyl. Examples include compounds obtained by adding 1 to 300 mol of alkylene oxide to unsaturated alcohols such as 2-buten-1-ol, 2-methyl-3-buten-1-ol, allyl alcohol, and methallyl alcohol. These compounds may be used alone or in combination of two or more. Among these compounds, a compound obtained by adding 1 to 300 mol of alkylene oxide to 3-methyl-3-buten-1-ol (isoprenol) is particularly preferable.

  As the alkylene oxide, for example, any two or more types of alkylene oxide selected from ethylene oxide, propylene oxide, butylene oxide, styrene oxide and the like may be added. In that case, random addition, block addition, and alternate addition Any of these may be used. Moreover, the terminal of the alkylene oxide added to unsaturated alcohol is a hydrogen atom or a C1-C20 hydrocarbon group. Here, as the hydrocarbon group having 1 to 20 carbon atoms, for example, an alkyl group having 1 to 20 carbon atoms (aliphatic or alicyclic alkyl group), an aryl group having 6 to 20 carbon atoms, for example, Examples thereof include a phenyl group, an alkylphenyl group, a phenylalkyl group, a phenyl group substituted with a (alkyl) phenyl group, and a naphthyl group.

  The average added mole number of the oxyalkylene group is 1 to 300. When the average added mole number decreases, the hydrophilicity of the monomer (a) decreases, and conversely, when the average added mole number increases, the reactivity of the monomer (a) decreases. Therefore, the average added mole number of the oxyalkylene group is preferably 10 to 300, more preferably 20 to 300, still more preferably 20 to 200, and particularly preferably 25 to 200.

  The carbon number of the oxyalkylene group is in the range of 2-18, preferably in the range of 2-8, more preferably in the range of 2-4.

  When one kind of monomer (a) is used, it is preferable to include an oxyethylene group as an essential component in the oxyalkylene group in order to ensure a balance between hydrophilicity and hydrophobicity, and further 50 mol%. The above is preferably an oxyethylene group. When using 2 or more types of monomers (a), it is preferable to include an oxyethylene group as an essential component in the oxyalkylene group of any one type of monomer (a).

  Specific examples of the oxyalkylene group moiety of the monomer (a) include polyethylene glycol mono (3-methyl-3-butenyl) ether and polyethylene glycol mono (3-methyl-2-butenyl). Ether, polyethylene glycol mono (2-methyl-3-butenyl) ether, polyethylene glycol mono (2-methyl-2-butenyl) ether, polyethylene glycol mono (1,1-dimethyl-2-propenyl) ether, polyethylene polypropylene glycol mono (3-methyl-3-butenyl) ether, methoxypolyethylene glycol mono (3-methyl-3-butenyl) ether, ethoxypolyethylene glycol mono (3-methyl-3-butenyl) ether, 1-propoxypolyethylene glycol mono 3-methyl-3-butenyl) ether, cyclohexyloxypolyethylene glycol mono (3-methyl-3-butenyl) ether, 1-octyloxypolyethylene glycol mono (3-methyl-3-butenyl) ether, nonylalkoxypolyethylene glycol mono ( 3-methyl 3-butenyl) ether, lauryl alkoxy polyethylene glycol mono (3-methyl-3-butenyl) ether, stearyl alkoxy polyethylene glycol mono (3-methyl-3-butenyl) ether, phenoxy polyethylene glycol mono (3-methyl- 3-butenyl) ether, naphthoxypolyethylene glycol mono (3-methyl-3-butenyl) ether, and the like.

  As the monomer (b), for example, the following formula (3):

[Wherein, R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom or a methyl group, and M represents a hydrogen atom, an alkali metal, an alkaline earth metal, a quaternary ammonium base, or an organic amine base. Or a hydrocarbon group having 1 to 20 carbon atoms]
In particular, an acrylic acid, methacrylic acid, crotonic acid, and their monovalent metal salts, divalent metal salts, quaternary ammonium salts, organic amine salts, etc. (Meth) acrylic acid monomers; and the like. These monomers (b) may be used alone or in combination of two or more. Among these monomers (b), acrylic acid, methacrylic acid, and salts thereof are preferable from the viewpoint of polymerizability, and acrylic acid and salts thereof are more preferable.

  As a (meth) acrylic-acid type monomer used as a monomer (b), the form containing a (meth) acrylic-acid dimer can also be used. Here, the “(meth) acrylic acid dimer” means a dimer formed by addition reaction of two molecules of (meth) acrylic acid, such as β-acryloxypropanoic acid or β-methacryloxy. There are salt-formers such as isobutanoic acid, β-methacryloxypropanoic acid and β-acryloxyisobutanoic acid, and alkali metal salts, alkaline earth metal salts and organic amine salts thereof. Among these, it is preferable to use acrylic acid and / or a salt-formation product of acrylic acid as the monomer component (b) in consideration of improvement in cement dispersion performance. Therefore, according to the above embodiment, in the salt formation product of acrylic acid and / or acrylic acid, these dimers, β-acryloxypropanoic acid and / or β-acryloxypropanoic acid alkali metal salt, alkaline earth The content of salt-forming substances such as metal salt and organic amine salt is preferably 5% by mass or less based on the (meth) acrylic acid monomer. When the content of the (meth) acrylic acid dimer exceeds 5% by mass, the cement dispersion performance of the resulting copolymer is lowered. The reason for this is not clear, but it is presumed that the presence of the (meth) acrylic acid dimer makes the resulting copolymer form different from the desired form. Therefore, the content of the (meth) acrylic acid dimer contained in the (meth) acrylic acid monomer is 5% by mass or less (that is, 0 to 5 with respect to the (meth) acrylic acid monomer). Mass%), but preferably 0 to 3 mass%, more preferably 0 to 1 mass%. Since the content of (meth) acrylic acid dimer is preferably as small as possible, in this range, the lower limit was set to 0% by mass. However, in the case of (meth) acrylic acid that is readily commercially available, The content of the (meth) acrylic acid dimer is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass, and still more preferably 0.01 to 1% by mass with respect to (meth) acrylic acid. %.

  Moreover, when using acrylic acid as a monomer component (b), it is so preferable that there are few impurities contained in this acrylic acid. Specifically, the content of furfural is preferably 1,000 ppm or less and the content of benzaldehyde is preferably 500 ppm or less; the content of furfural is 100 ppm or less and the content of benzaldehyde is 100 ppm or less. More preferably; the content of furfural is 50 ppm or less, the content of benzaldehyde is 50 ppm or less; and the content of furfural is 10 ppm or less, and the content of benzaldehyde is particularly preferably 10 ppm or less. Although maleic acid may be contained in acrylic acid, the content of maleic acid present as an impurity in acrylic acid in such a case is preferably 500 ppm or less, more preferably 50 ppm or less. On the other hand, if necessary, maleic acid may be positively blended as the monomer component (b). In addition, (meth) acrylic acid dimer may be generated during storage of (meth) acrylic acid monomer, and in order to prevent such formation, (meth) acrylic acid monomer is used in the polymerization reaction. Until use, it is preferable to store at 40 ° C. or lower, more preferably 30 ° C. or lower.

  Specific examples of the monomer (c) copolymerizable with the monomer (a) and / or the monomer (b) include maleic acid, maleic anhydride, fumaric acid, itaconic acid, and citracone. Acids, and unsaturated dicarboxylic acid monomers such as these monovalent metal salts, divalent metal salts, quaternary ammonium salts, and organic amine salts; Half esters and diesters with 30 alcohols; half amides and diamides of the unsaturated dicarboxylic acid monomers and amines having 1 to 30 carbon atoms; alkylenes having 2 to 18 carbon atoms in the alcohols and amines Half esters and diesters of an alkyl (poly) alkylene glycol to which 1 to 500 moles of oxide are added and the unsaturated dicarboxylic acid monomer; the unsaturated dicarboxylic acid single monomer Half-esters and diesters of glycerides with glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of these glycols; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate , Esters of unsaturated monocarboxylic acids such as glycidyl (meth) acrylate, methyl crotonate, ethyl crotonate, and propyl crotonate with alcohols having 1 to 30 carbon atoms; alcohols having 1 to 30 carbon atoms and 2 carbon atoms Esters of alkoxy (poly) alkylene glycol to which 1 to 500 moles of alkylene oxide of -18 are added and unsaturated monocarboxylic acids such as (meth) acrylic acid; (poly) ethylene glycol monomethacrylate, (poly) propylene glycol mono 1-500 molar adducts of alkylene oxides of 2-18 carbon atoms to unsaturated monocarboxylic acids such as (meth) acrylic acid, such as tacrylate, (poly) butylene glycol monomethacrylate; maleamic acid and carbon atoms Half amides of 2-18 glycols or polyalkylene glycols having an addition mole number of these glycols of 2 to 500; triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, polypropylene glycol di ( (Poly) alkylene glycol di (meth) acrylates such as (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate; hexanediol di (meth) acrylate, trimethylolpropane tri ( Bifunctional (meth) acrylates such as (meth) acrylate and trimethylolpropane di (meth) acrylate; (poly) alkylene glycol dimaleates such as triethylene glycol dimaleate and polyethylene glycol dimaleate; vinyl sulfonate and (meth) allyl Sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acryloxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutylsulfonate, (meth) acrylamide methylsulfonic acid, (meth) acrylamide Unsaturated sulfonic acids such as til sulfonic acid, 2-methylpropane sulfonic acid (meth) acrylamide, styrene sulfonic acid, and their monovalent metal salts, divalent metal salts, quaternary ammonium salts and organic amine salts; methyl (meta ) Amides of unsaturated monocarboxylic acids and amines having 1 to 30 carbon atoms such as acrylamide; vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene; 1,4-butane Alkanediol mono (meth) acrylates such as diol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate; butadiene, isoprene, 2-methyl-1 , 3-butadiene, 2-chloro-1,3-butadiene, etc. Ens; unsaturated amides such as (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; (meth) acrylonitrile, α-chloroacrylonitrile, etc. Unsaturated cyanides; unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethyl (meth) acrylate Unsaturated amines such as aminopropyl, dibutylaminoethyl (meth) acrylate, and vinylpyridine; divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate; (meth) allyl alcohol, glycidyl (meth) allyl Such as ether Ryls; unsaturated amino compounds such as dimethylaminoethyl (meth) acrylate; vinyl ethers such as methoxypolyethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, methoxypolyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl ether Or allyl ethers; polydimethylsiloxane propylaminomaleamic acid, polydimethylsiloxane aminopropyleneaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- (dipropyleneaminomaleamide) Acid), polydimethylsiloxane- (1-propyl-3-acrylate), polydimethylsiloxane- (1-propylene) And siloxane derivatives such as polydimethylsiloxane-bis- (1-propyl-3-acrylate) and polydimethylsiloxane-bis- (1-propyl-3-methacrylate). These monomers (c) may be used alone or in combination of two or more. Among these monomers (c), esters of unsaturated monocarboxylic acids such as methyl (meth) acrylate, ethyl (meth) acrylate, glycidyl (meth) acrylate and alcohols having 1 to 30 carbon atoms are preferable.

  The polymerization reaction can be performed by a conventionally known method such as solution polymerization or bulk polymerization. The solution polymerization can be performed either batchwise or continuously. Usable solvents include water; lower alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, n-hexane and cyclohexane; esters such as ethyl acetate Ketones such as acetone and methyl ethyl ketone; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; and the like. These solvents may be used alone or in combination of two or more. Of these solvents, it is preferable to use at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms because of the solubility of the raw material monomers and the resulting copolymer. It is more preferable to use water as a solvent because the solvent removal step can be omitted.

  In the method for producing a copolymer according to the present invention, it is preferable to use a chain transfer agent in the polymerization reaction or to adjust the pH to 5 or more after polymerization. By using a chain transfer agent and / or adjusting the pH, for example, a copolymer that exhibits excellent performance as a cement admixture can be effectively obtained. If a chain transfer agent is used in the polymerization reaction, the molecular weight of the resulting copolymer can be easily adjusted. In particular, it is effective to use a chain transfer agent when the polymerization reaction is performed at a high concentration of 30% by mass or more based on the total amount of raw materials used during polymerization.

  The chain transfer agent is not particularly limited as long as the molecular weight of the copolymer can be adjusted. Specifically, for example, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3- Thiol compounds such as mercaptopropionic acid, thiomalic acid, octyl thioglycolate, octyl 3-mercaptopropionate, 2-mercaptoethanesulfonic acid, n-dodecyl mercaptan, octyl mercaptan, butylthioglycolate; carbon tetrachloride, methylene chloride Halides such as bromoform and bromotrichloroethane; secondary alcohols such as isopropanol; phosphorous acid, hypophosphorous acid and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogensulfite , Dithionite, meta Lower oxides and salts of sulfurous acid and its salts (sodium sulfite, potassium sulfite, sodium bisulfite, potassium hydrogen sulfite, sodium dithionite, potassium dithionite, sodium metabisulfite, potassium metabisulfite, etc.) Can be used.

  Furthermore, a monomer having a high chain transfer property can also be used as a chain transfer agent. Specifically, for example, α, β-unsaturated dicarboxylic acid compounds such as maleic acid, fumaric acid and citraconic acid, and derivatives thereof And salts thereof (more specifically, examples of derivatives include, for example, half esters with alcohols having 1 to 30 carbon atoms; half amides with amines having 1 to 30 carbon atoms; Half-amides or half-esters with amino alcohols; Half-esters with compounds (x) obtained by adding an average of 1 to 300 moles of alkylene oxide having 2 to 18 carbon atoms to the alcohols; One end of the compound (x) A half amide with a compound in which a hydroxyl group is aminated; a glycol having 2 to 18 carbon atoms or an average addition mole number of these glycols of 2 to 30 Examples of salts include half esters with 0 polyalkylene glycols; half amides of glycols having 2 to 18 carbon atoms or polyalkylene glycols having an average addition mole number of these glycols of 2 to 300 and maleamic acid; Examples thereof include monovalent metal salts, divalent metal salts, ammonium salts, organic amine salts, etc.); allyl compounds such as allyl alcohol and allyl sulfonic acid (salt), and the average number of added moles thereof is 2 -300 to C2-C18 alkylene oxide adducts; methallyl compounds such as methallyl alcohol and methallyl sulfonic acid (salt), and addition of C2-C18 alkylene oxides with an average addition mole number of 2 to 300 Thing; etc. are mentioned.

  In addition, said chain transfer agent may be used individually or may use 2 or more types together.

  It is preferable that the chain transfer agent is always present in the reaction system during the polymerization reaction. In particular, when a thiol chain transfer agent or a lower oxide and a salt thereof are used as the chain transfer agent, the chain transfer agent is continuously added by dropping or the like without adding the chain transfer agent all at once, It is effective to add over time. If the concentration of the chain transfer agent relative to the monomer is extremely different between the initial and second half of the reaction, and the chain transfer agent is insufficient in the second half of the reaction, the molecular weight of the copolymer becomes extremely large. As the performance decreases.

  When supplying the chain transfer agent into the reaction system, it is preferable to supply the chain transfer agent in a line different from the acidic raw material such as the monomer (b) or peroxide. When using lower oxides and salts thereof, it is effective to supply them on a line different from the acidic raw material. For example, when a thiol chain transfer agent is supplied in the same line as the monomer (b), the chain transfer agent acts on the monomer (b) as a reaction initiator to cause partial polymerization, resulting in a homopolymer. For example, the performance as a cement admixture decreases. In addition, when the lower oxide and its salt are supplied in the same line as the peroxide, the lower oxide and its salt react with the peroxide, and the activity is lost before the peroxide acts as a reaction initiator. It will end up.

  The copolymer obtained by the polymerization reaction is preferably adjusted to a pH of 5 or more from the viewpoint of handleability. However, when the polymerization reaction is performed at a pH of 5 or more, the polymerization rate decreases, Since the copolymerizability deteriorates and, for example, the dispersibility decreases as a copolymer for cement admixture, it is preferable to perform the polymerization reaction at a pH of less than 5 and adjust the pH to 5 or more after polymerization. The pH can be adjusted using, for example, an alkaline substance such as inorganic salts such as monovalent metal and divalent metal hydroxides and carbonates; ammonia; organic amines; When a chain transfer agent is used, the obtained copolymer can be used as it is, for example, as a main component of a cement admixture.

  As the polymerization initiator, a normal radical polymerization initiator can be used. Examples of radical polymerization initiators used in aqueous solution polymerization include peroxides such as persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate; hydrogen peroxide; and the like as azo initiators. Azoamidine compounds such as 2,2′-azobis-2-methylpropionamidine hydrochloride, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, 2-carbamoyl Azoisobutyronitrile; and the like are used.

  In addition, as a radical polymerization initiator in the case of performing solution polymerization or bulk polymerization using lower alcohols, aromatic or aliphatic hydrocarbons, esters, ketones or the like as solvents, for example, peroxides, benzoyl peroxide , Lauroyl peroxide, sodium peroxide, t-butyl hydroperoxide, cumene hydroperoxide and the like are used, and azobisisobutyronitrile and the like are used as the azo initiator. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above radical polymerization initiators. The bulk polymerization is performed within a temperature range of 50 to 200 ° C.

  In the polymerization reaction, it is preferable to start the polymerization with a redox polymerization initiator in which the peroxide and the reducing agent are used in combination.

The reducing agent is not particularly limited as long as it is a general reducing agent. For example, iron (II), tin (II), titanium (III), chromium, and the like represented by mole salts. (II), salts of metals in a low valence state such as V (II), Cu (II); amine compounds such as monoethanolamine, diethanolamine, triethanolamine, hydroxylamine, hydroxylamine hydrochloride, hydrazine and the like include groups such as - sodium dithionite, sodium formaldehyde sulfoxylate, in addition, such as sodium hydroxy methane sulfinate _{dihydrate, -SH, -SO 2 H, -NHNH} 2, -COCH (OH); salt Organic compounds and salts thereof; alkalis such as sodium sulfite, sodium bisulfite, metabisulfite Metal sulfites, lower oxides and salts thereof such as hypophosphorous acid, sodium hypophosphite, sodium hydrosulfite, sodium hyponitrite; invert sugars such as D-fructose and D-glucose; thiourea, thiourea dioxide, etc. Thiourea compounds; L-ascorbic acid (salt), L-ascorbic acid ester, erythorbic acid (salt), erythorbic acid ester; and the like.

  Specific examples of the combination of the peroxide and the reducing agent include, for example, a combination of benzoyl peroxide and an amine, and a combination of cumene hydroperoxide and a metal compound such as iron (II) or Cu (II). . In particular, a combination of a water-soluble peracid peroxide and a reducing agent is preferable. For example, a combination of hydrogen peroxide and L-ascorbic acid, a combination of hydrogen peroxide and erythorbic acid, a combination of hydrogen peroxide and a mol salt. The combination of sodium persulfate and sodium bisulfite is particularly preferred. A particularly preferred combination is a combination of hydrogen peroxide and L-ascorbic acid.

  The amount of peroxide used is preferably 0.01 mol% or more, more preferably 0.1 mol% or more, still more preferably 0.5 mol% or more, further preferably, relative to the total amount of monomer components. Is 1 mol% or more, preferably 30 mol% or less, more preferably 20 mol% or less, still more preferably 10 mol% or less, and further preferably 5 mol% or less. If the amount of peroxide used is less than 0.01 mol%, the amount of unreacted monomer may increase. On the other hand, when the amount of peroxide used exceeds 30 mol%, a polycarboxylic acid having a large number of oligomer parts may be obtained.

  The amount of the reducing agent used is preferably 0.1 mol% or more, more preferably 1 mol% or more, still more preferably 5 mol% or more, still more preferably 10 mol% or more, more preferably with respect to the peroxide. It is 25 mol% or more, more preferably 50 mol% or more, preferably 500 mol% or less, more preferably 300 mol% or less, still more preferably 200 mol% or less, still more preferably 100 mol% or less. When the amount of the reducing agent used is less than 0.1 mol%, active radicals are not sufficiently generated, and the amount of unreacted monomers may increase. On the other hand, when the amount of the reducing agent used exceeds 500 mol%, the reducing agent remaining without reacting with hydrogen peroxide may increase.

  In the polymerization reaction, it is preferable that at least one of the peroxide and the reducing agent is always present in the reaction system. Specifically, the peroxide and the reducing agent need not be added all at once. For example, they may be added over a long period of time, for example, by dropping them continuously or by adding them separately. When the peroxide and reducing agent are simultaneously added at once, the peroxide and reducing agent react rapidly, and immediately after the addition, reaction control becomes difficult due to a large amount of reaction heat. Since the radical concentration rapidly decreases, a large amount of unreacted monomer remains. Furthermore, since the radical concentration with respect to the monomer is extremely different between the initial stage and the latter half of the reaction, the molecular weight distribution becomes extremely large. For example, the performance as a cement admixture is lowered. In addition, it is preferable that the time from the introduction of one to the start of the other is within 5 hours, more preferably within 3 hours, and particularly preferably within 1 hour.

  In the polymerization reaction, in order to obtain high reactivity of the monomer, the half-life of the radical polymerization initiator is preferably 0.5 to 500 hours, more preferably 1 to 300 hours, still more preferably 3 to 150. For example, when persulfate is used as an initiator, the temperature of the polymerization reaction is suitably in the range of 40 to 100 ° C., but it is 42 to 98 ° C. Within the range, preferably within the range of 45 to 90 ° C, more preferably within the range of 50 to 80 ° C. When the initiator is a combination of hydrogen peroxide and L-ascorbic acid (salt), the temperature of the polymerization reaction is suitably in the range of 30-100 ° C, but preferably in the range of 35-98 ° C. Within the range of 40-95 ° C, more preferably within the range of 42-90 ° C, even more preferably within the range of 45-85 ° C. The time for the polymerization reaction is suitably in the range of 0.5 to 10 hours, preferably 0.5 to 8 hours, more preferably 1 to 6 hours. If the time for the polymerization reaction is too long or too short from this range, it is not preferable because the polymerization rate is lowered and the productivity is lowered.

  The amount of all monomers used in the polymerization reaction is 20 to 95% by mass, preferably 30 to 93% by mass, more preferably 40 to 90% by mass, based on the total amount of raw materials. If the amount is too much or too little than this range, the polymerization rate and productivity are lowered, which is not preferable.

  As a method for charging each monomer into the reaction vessel at the time of polymerizing the monomer component, in the polymerization step, the cumulative charging rate of the monomer (b) into the reaction vessel (total amount of the monomer (b) The cumulative charge ratio of the monomer (a) to the reaction vessel (mass% of the charged monomer (b) with respect to the charged quantity) It is preferable that there is a point in time when the amount of the monomer (a) is large. Specifically, for example, the following method is exemplified.

  1. A method in which the entire amount of the monomer (a) is collectively charged into the reaction vessel before the polymerization is started, and the entire amount of the monomer (b) is divided or continuously charged into the reaction vessel after the polymerization initiator has been charged into the reaction vessel. .

  2. The whole amount of monomer (a) and a part of monomer (b) are charged into the reaction vessel before the start of polymerization, and the remainder of monomer (b) is removed after the start of the polymerization initiator into the reaction vessel. A method of dividing or continuously charging into a reaction vessel.

  3. A part of the monomer (a) is put into the reaction vessel before the start of polymerization, and the remainder of the monomer (a) and the total amount of the monomer (b) are added after the start of the introduction of the polymerization initiator into the reaction vessel. A method of dividing or continuously charging into a reaction vessel.

  4). A part of the monomer (a) and a part of the monomer (b) are charged into the reaction vessel before the start of polymerization, and the remainder of the monomer (a) after the start of charging the polymerization initiator into the reaction vessel And the remainder of the monomer (b) is divided or continuously charged into the reaction vessel, and the monomer (b) is charged into the reaction vessel at the point when the monomer (a) is charged into the reaction vessel. A way to delay the end point.

  5. A part of the monomer (a) and a part of the monomer (b) are charged into the reaction vessel before the start of polymerization, and the remainder of the monomer (a) after the start of charging the polymerization initiator into the reaction vessel And the remainder of the monomer (b) are divided or continuously charged into the reaction vessel, and the cumulative charge ratio of the monomer (b) to the reaction vessel (the amount already charged relative to the total amount of monomer (b) charged) Of the monomer (a) to the reaction vessel (according to the total mass of the monomer (a)). In which there is a point in time when there is a large mass%).

  6). After the start of charging the polymerization initiator into the reaction vessel, the whole amount of monomer (a) and the whole amount of monomer (b) are divided or continuously charged into the reaction vessel, and the monomer (b) reaction vessel Cumulative charge ratio of monomer (a) to the reaction vessel (single mass% of monomer (b) already charged relative to the total charge of monomer (b)) A method in which there is a point in time when there is a large amount of the monomer (a) already charged relative to the total charge of the monomer (a).

  According to the methods exemplified in the above 1 to 6, the monomer (a) and the monomer (b), although the polymerizability of the monomer (a) is lower than the polymerizability of the monomer (b) ) Can be efficiently copolymerized. In addition, the method for charging the monomer (c) into the reaction vessel is not particularly limited, a method in which the entire amount is initially charged into the reaction vessel, a method in which the entire amount is divided or continuously charged into the reaction vessel, and a part of the reaction vessel Any of the methods may be used in which the initial charging is performed and the remainder is divided or continuously charged into the reaction vessel. Furthermore, the neutralization rate of the monomer (b) and the monomer (c) is not particularly limited, and the neutralization rate may be changed so as not to affect the polymerization initiator, the chain transfer agent and the like. The polymerization reaction is carried out under such conditions, and after completion of the reaction, neutralization and concentration adjustment are performed as necessary.

  The ratio of each monomer used when synthesizing the copolymer of the present invention is not particularly limited as long as the monomer (a) and the monomer (b) are essential. The range of monomer (a) / monomer (b) / monomer (c) = 1 to 99/1 to 99/0 to 70 (mass%) is appropriate. ) / Monomer (b) / monomer (c) = preferably within the range of 50 to 99/1 to 50/0 to 49 (mass%), monomer (a) / monomer (b) / Monomer (c) = more preferably within the range of 55 to 98/2 to 45/0 to 40 (mass%), monomer (a) / monomer (b) / monomer (c) = More preferably within the range of 60 to 97/3 to 40/0 to 30 (mass%). However, the total amount of the monomer (a), the monomer (b) and the monomer (c) is 100% by mass. The weight average molecular weight of the copolymer is preferably 10,000 or more, more preferably 15,000 or more, and still more preferably, in terms of polyethylene glycol by gel permeation chromatography (hereinafter sometimes referred to as “GPC”). It is 20,000 or more, preferably 300,000 or less, more preferably 200,000 or less, further preferably 100,000 or less, still more preferably 80,000 or less, and further preferably 70,000 or less. By selecting the weight ratio of these monomers and the range of the weight average molecular weight, for example, a copolymer for cement admixture that exhibits higher dispersion performance is obtained.

  As described above, in the method for producing a copolymer according to the present invention, a monomer (a) containing 1 to 20% by mass of a polyalkylene glycol is used as at least a part of the monomer (a). 10 mass% or more is used with respect to the total amount of body components. The polyalkylene glycol content of the monomer (a) is usually in the range of 1 to 20% by mass, preferably 1.5 to 15% by mass, more preferably 2 to 10% by mass.

  Moreover, it is preferable to use the monomer (a) containing 100 to 10,000 ppm of isoprene on a mass basis as at least a part of the monomer (a). The isoprene content of the monomer (a) is preferably in the range of 100 to 10,000 ppm, more preferably 150 to 5,000 ppm, and even more preferably 200 to 2,500 ppm on a mass basis.

  Thus, the monomer (a) containing a predetermined amount of polyalkylene glycol or isoprene as at least a part of the monomer (a) is 10% by mass or more based on the total amount of the monomer components. When the obtained copolymer is used as a cement admixture, the dispersibility and dispersion retention of cement and the state of mortar are improved.

≪Method for producing unsaturated monomer≫
The method for producing an unsaturated monomer according to the present invention comprises the following formula (2):

[Wherein R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1]
By adding an alkylene oxide to the unsaturated alcohol represented by the following formula (1):

[Wherein, R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and AO represents 2 carbon atoms. -18 represents an oxyalkylene group, n represents the average number of moles added of the oxyalkylene group, represents a number of 1 to 300, and when n is 2 or more, a plurality of AOs are the same or different. X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1.]
A unsaturated alcohol containing 100 to 10,000 ppm (by mass) of water is used as at least a part of the unsaturated alcohol. It is characterized by.

  Hereinafter, the method for producing an unsaturated monomer according to the present invention will be described in detail. The unsaturated monomer means an unsaturated polyalkylene glycol ether-based monomer. However, as in the description of the method for producing a copolymer having a polyalkylene glycol chain, simply “monomer (a ) ". Further, the unsaturated alcohol represented by the above formula (2) may be simply referred to as “unsaturated alcohol”.

  The method for producing an unsaturated monomer according to the present invention includes adding an alkylene oxide to an unsaturated alcohol.

  The unsaturated alcohol is not particularly limited as long as it is an unsaturated alcohol represented by the above formula (2). Specifically, for example, 3-methyl-3-buten-1-ol, 3 -Methyl-2-buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-2-buten-1-ol, 2-methyl-3-buten-1-ol, allyl alcohol, And methallyl alcohol. Of these unsaturated alcohols, 3-methyl-3-buten-1-ol (isoprenol) is particularly preferred.

  The alkylene oxide is not particularly limited as long as it is an alkylene oxide having 2 to 18 carbon atoms. Specific examples thereof include ethylene oxide, propylene oxide, butylene oxide, and styrene oxide. These alkylene oxides may be used alone or in combination of two or more. When two or more alkylene oxides are used in combination, any of random addition, block addition, alternating addition, and the like may be used. Moreover, the terminal of the alkylene oxide added to unsaturated alcohol is a hydrogen atom or a C1-C20 hydrocarbon group. Here, as the hydrocarbon group having 1 to 20 carbon atoms, for example, an alkyl group having 1 to 20 carbon atoms (aliphatic or alicyclic alkyl group), an aryl group having 6 to 20 carbon atoms, for example, Examples thereof include a phenyl group, an alkylphenyl group, a phenylalkyl group, a phenyl group substituted with a (alkyl) phenyl group, and a naphthyl group.

  The average added mole number of alkylene oxide is 1 to 300. When the average added mole number decreases, the hydrophilicity of the monomer (a) decreases, and conversely, when the average added mole number increases, the reactivity of the monomer (a) decreases. Therefore, the average number of added moles of alkylene oxide is preferably 10 or more, more preferably 20 or more, still more preferably 40 or more, still more preferably 50 or more, and preferably 300 or less, more preferably 200 or less, More preferably, it is 150 or less, More preferably, it is 100 or less.

  Carbon number of alkylene oxide is usually in the range of 2-18, preferably in the range of 2-8, more preferably in the range of 2-4.

  Examples of the unsaturated polyalkylene glycol ether monomer, that is, the monomer (a) include the monomers listed above in the description of the method for producing a copolymer having a polyalkylene glycol chain.

  The addition reaction can be performed by a conventionally known method. For example, an unsaturated alcohol and an alkylene oxide may be mixed and stirred in an inert gas atmosphere in the presence of a base. In the case of alkylene oxide having a small number of carbon atoms, it is in a gaseous state at normal temperature and normal pressure, so that it is necessary to perform an addition reaction under pressure using, for example, a pressure vessel such as an autoclave.

  As an inert gas, helium, argon, nitrogen etc. are mentioned, for example. These inert gases may be used alone or in combination of two or more. Of these inert gases, nitrogen is particularly preferable from the viewpoint of availability and economy.

  Examples of the base include alkali metals such as lithium, sodium and potassium; alkali metal hydrides such as lithium hydride, sodium hydride and potassium hydride; organolithium compounds such as n-butyllithium; sodium amide; lithium hydroxide Metal hydroxides such as sodium hydroxide and potassium hydroxide. These bases may be used alone or in combination of two or more. Of these bases, sodium hydride, sodium hydroxide, and potassium hydroxide are particularly preferred from the viewpoints of ease of handling and economy.

  When the temperature of the addition reaction increases, the thermal decomposition of the monomer (a) proceeds and the amount of by-produced polyethylene glycol and isoprene increases, so that these impurities are contained in the monomer (a) in a predetermined amount. Thus, it is necessary to adjust the temperature of the addition reaction as appropriate. Therefore, the temperature of the addition reaction is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, further preferably 90 ° C. or higher, more preferably 100 ° C. or higher, and preferably 180 ° C. or lower, more preferably 170 ° C. ° C or lower, more preferably 160 ° C or lower, more preferably 150 ° C or lower, further preferably 140 ° C or lower, more preferably 130 ° C or lower, and further preferably 120 ° C or lower.

  The pressure of the addition reaction may be appropriately adjusted so that the addition reaction proceeds smoothly, and is not particularly limited, but is usually 1.0 MPa or less, preferably 0.9 MPa or less, more preferably 0. .8 MPa or less. The addition reaction time may be appropriately adjusted according to the amount of unsaturated alcohol charged and the amount of alkylene oxide added, and is not particularly limited. For example, it is usually 0.5 to 24 hours, preferably 2 Within 20 hours, more preferably within 5-18 hours.

  The average number of moles of alkylene oxide added to the unsaturated alcohol is determined by the amount of unsaturated alcohol charged and the amount of alkylene oxide added. However, the desired amount of alkylene oxide may be added to the unsaturated alcohol in a single reaction, or may be added in multiple reactions. For example, less alkylene oxide is added in the first reaction to the unsaturated alcohol, and the remaining amount of alkylene is added to the alkylene oxide adduct of the resulting unsaturated alcohol in the subsequent reaction. Oxides may be added.

  As described above, in the method for producing an unsaturated monomer according to the present invention, when producing the monomer (a) by adding an alkylene oxide to the unsaturated alcohol, at least a part of the unsaturated alcohol, An unsaturated alcohol containing 100 to 10,000 ppm of water on a mass basis is used. The water content of the unsaturated alcohol is preferably 100 ppm or more, more preferably 150 ppm or more, further preferably 200 ppm or more, more preferably 300 ppm or more, further preferably 500 ppm or more, and preferably 10, ppm or more on a mass basis. 000 ppm or less, more preferably 8,000 ppm or less, further preferably 5,000 ppm or less, still more preferably 2,500 ppm or less, and still more preferably 1,000 ppm or less.

  Thus, by using an unsaturated alcohol containing a predetermined amount of water as at least a part of the unsaturated alcohol, when the alkylene oxide is added to the unsaturated alcohol, the water contained in the unsaturated alcohol is reduced. It reacts with the alkylene oxide, and the produced monomer (a) is thermally decomposed to produce polyalkylene glycol as a by-product. A monomer (a) containing a predetermined amount of polyalkylene glycol and isoprene simultaneously by-produced by thermal decomposition of the monomer (a) is used in an amount of 10% by mass or more based on the total amount of the monomer components. Thus, when the obtained copolymer is used as a cement admixture, the dispersibility and dispersion retention of cement and the state of mortar are improved.

  The unsaturated alcohol may contain an unsaturated aldehyde as an impurity. For example, 3-methyl-3-buten-1-ol may contain 3-methyl-2-butenal (3-methylcrotonaldehyde) as an impurity. When such an unsaturated aldehyde is contained in a large amount, it causes coloring, and therefore it is preferable that the amount is as small as possible. The allowable amount of unsaturated aldehyde contained in the unsaturated alcohol is preferably about 0.5% by mass or less, more preferably 0.2% by mass or less, further preferably 0.1% by mass or less, and further preferably 0.07%. It is not more than mass%, more preferably not more than 0.05 mass%.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. It is also possible to implement, and they are all included in the technical scope of the present invention. In the following production examples, “%” and “ppm” are based on mass unless otherwise specified.

  First, a method for measuring the concentration of impurities such as polyethylene glycol and isoprene will be described.

<Measurement of polyethylene glycol concentration>
The concentration of polyethylene glycol was measured by gel permeation chromatography under the following conditions.

Apparatus: Waters Alliance (2695);
Analysis software: Emper Professional + GPC option from Waters;
Column: Shodex Ashipak GF-1G-7B + GF-310-HQ;
Detector: differential refractometer (RI) detector (Waters 2414);
Eluent: Solution mixed at a ratio of water / acetonitrile = 98/2 (mass ratio);
Flow rate: 1.0 mL / min;
Column / detector temperature: 40 ° C .;
Measurement time: 30 minutes;
Sample injection volume: 200 μL (prepared with the above eluent to a sample concentration of 0.1%);
GPC standard sample: polyethylene glycol manufactured by GL Sciences Mp = 960, 1,470, 4,020, 6,450, 11,840;
Calibration curve: Created by a cubic equation using the Mp value of polyethylene glycol.

<Measurement of isoprene concentration>
The concentration of isoprene was measured by gas chromatography under the following conditions.

GC-MS: Shimadzu GC-17A, QP-5000;
Headspace: HS-40 manufactured by Perkin Elmer;
Column: DB-1 manufactured by J & W (inner diameter 0.32 mm × length 60 m × film thickness 1 μm);
Mobile phase: helium gas;
Flow rate: 130 kPa (headspace inlet regulator);
Column / detector temperature: 40 ° C .;
Column heating: The temperature was raised from 80 to 250 ° C. at 5 ° C./min and held at 250 ° C. for 10 minutes;
Injection temperature: 250 ° C;
Sample injection volume: 200 μL (prepared with the above eluent to a sample concentration of 0.1%);
HS sample heating conditions: 130 ° C. × 10 minutes;
HS needle, transformer temperature: 170 ° C .;
GC-MS interface temperature: 250 ° C.

  Next, production examples of unsaturated alcohols in which ethylene oxide is added to 3-methyl-3-buten-1-ol will be described.

≪Production Example 1≫
Into an autoclave equipped with a thermometer, pressure gauge, and stirrer, was charged 1,870 g of 3-methyl-3-buten-1-ol (containing 500 ppm of water) and 3.6 g of sodium hydride, and the autoclave was purged with nitrogen under stirring. And heated to 120 ° C. under a nitrogen atmosphere. The temperature was maintained at 120 ° C., the initial pressure was set to 0.09 MPa, and 9,560 g of ethylene oxide was added over 15 hours. During this time, the reaction temperature was maintained at 120 ° C. ± 5 ° C., and the reaction pressure was maintained at 0.78 MPa or less. The reaction temperature was further maintained for 1 hour to complete the addition reaction of ethylene oxide to 3-methyl-3-buten-1-ol, and an average of 10 mol of ethylene oxide was added to 3-methyl-3-buten-1-ol. 11,433 g of unsaturated alcohol was obtained. When the concentration of impurities contained in this unsaturated alcohol was measured, it was 1.5% for polyethylene glycol and 200 ppm for isoprene.

≪Production Example 2≫
An autoclave equipped with a thermometer, pressure gauge, and stirrer was charged with 1,145 g of the unsaturated alcohol synthesized in Production Example 1 and 1.2 g of sodium hydride, and the autoclave was purged with nitrogen under stirring, and 120 ° C. under a nitrogen atmosphere. Heated. The temperature was maintained at 120 ° C., the initial pressure was set to 0.16 MPa, and 3,825 g of ethylene oxide was added over 12 hours. During this time, the reaction temperature was maintained at 120 ° C. ± 5 ° C., and the reaction pressure was maintained at 0.78 MPa or less. Further, the reaction temperature was maintained for 1 hour to complete the addition reaction of ethylene oxide to the raw material unsaturated alcohol, and an unsaturated alcohol having an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol was obtained. 970 g was obtained. When the concentration of impurities contained in the unsaturated alcohol was measured, it was 3.3% for polyethylene glycol and 500 ppm for isoprene.

≪Production Example 3≫
An autoclave equipped with a thermometer, pressure gauge, and stirrer was charged with 1,145 g of the unsaturated alcohol synthesized in Production Example 1 and 1.2 g of sodium hydride, and the autoclave was purged with nitrogen under stirring, and 140 ° C. under a nitrogen atmosphere. Heated. The temperature was maintained at 140 ° C., the initial pressure was set to 0.16 MPa, and 3,825 g of ethylene oxide was added over 12 hours. During this time, the reaction temperature was maintained at 140 ° C. ± 5 ° C., and the reaction pressure was maintained at 0.78 MPa or less. Further, the reaction temperature was maintained for 1 hour to complete the addition reaction of ethylene oxide to the raw material unsaturated alcohol, and an unsaturated alcohol having an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol was obtained. 969 g was obtained. When the concentration of impurities contained in the unsaturated alcohol was measured, polyethylene glycol was 7.2% and isoprene was 900 ppm.

≪Comparative Production Example 1≫
An autoclave equipped with a thermometer, pressure gauge, and stirrer was charged with 1,870 g of 3-methyl-3-buten-1-ol and 3.6 g of sodium hydride. Pressurized and replaced with nitrogen. The temperature was set to 120 ° C., the initial pressure was set to 0.09 MPa, and 9,560 g of ethylene oxide was added over 15 hours. During this time, the reaction temperature was maintained at 120 ° C. ± 5 ° C., and the reaction pressure was maintained at 0.78 MPa or less. The reaction temperature was further maintained for 1 hour to complete the addition reaction of ethylene oxide to 3-methyl-3-buten-1-ol, and an average of 10 mol of ethylene oxide was added to 3-methyl-3-buten-1-ol. 11,429 g of unsaturated alcohol was obtained. When the concentration of impurities contained in the unsaturated alcohol was measured, polyethylene glycol was 0.6% and isoprene was 60 ppm.

≪Comparative Production Example 2≫
An autoclave equipped with a thermometer, pressure gauge, and stirrer was charged with 1,145 g of the unsaturated alcohol synthesized in Comparative Production Example 1 and 1.2 g of sodium hydride, dehydrated and heated, dehydrated and degassed, and then added with nitrogen. And nitrogen substitution was performed. The temperature was set to 120 ° C., the initial pressure was set to 0.16 MPa, and 3,825 g of ethylene oxide was added over 12 hours. During this time, the reaction temperature was maintained at 120 ° C. ± 5 ° C., and the reaction pressure was maintained at 0.78 MPa or less. Further, the reaction temperature was maintained for 1 hour to complete the addition reaction of ethylene oxide to the raw material unsaturated alcohol, and an unsaturated alcohol having an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol was obtained. 968 g was obtained. When the concentration of impurities contained in the unsaturated alcohol was measured, polyethylene glycol was 0.9% and isoprene was 90 ppm.

  Next, a method for measuring the weight average molecular weight of a polymer having a polyalkylene glycol chain will be described.

<Measurement of weight average molecular weight of polymer>
The weight average molecular weight of the polymer having a polyalkylene glycol chain was measured by gel permeation chromatography under the following conditions.

Apparatus: Waters Alliance (2695);
Analysis software: Emper Professional + GPC option from Waters;
Column used: TSKgel guard column manufactured by Tosoh Corporation (inner diameter 6.0 × 40 mm) + G4000SWXL + G3000SWXL + G2000SWXL (each inner diameter 7.8 × 300 mm);
Detector: differential refractometer (RI) detector (Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters 2996);
Eluent: A mixture of acetonitrile / 50 mM sodium acetate ion exchange aqueous solution = 40/60 (vol%) adjusted to pH 6.0 by adding acetic acid was used;
Flow rate: 1.0 mL / min;
Column / detector temperature: 40 ° C .;
Measurement time: 45 minutes;
Sample solution injection volume: 100 μL (adjusted with the above eluent so that the sample concentration is 0.5 wt%);
GPC standard sample: polyethylene glycol [peak top molecular weight (Mp) = 272,500, 219,300 (above, manufactured by GL Sciences), 107,000, 50,000, 24,000 (above, manufactured by Tosoh Corporation), 11, 9 points of 840, 6,450, 4,250, 1,470 (above, manufactured by GL Sciences)];
Calibration curve: Created by a cubic equation using the Mp value of polyethylene glycol.

  Next, a production example of a polymer having a polyalkylene glycol chain will be described.

<< Production Example 4 >>
As an acrylic acid aqueous solution, an aqueous solution in which 64.64 g of acrylic acid was dissolved in 61.85 g of water was prepared. As an aqueous solution of a chain transfer agent, an aqueous solution was prepared by dissolving 2.14 g of 3-mercaptopropionic acid and 0.99 g of L-alcorbic acid in 96.87 g of water. As an aqueous solution of the polymerization initiator, an aqueous solution in which 2.54 g of 30% hydrogen peroxide was dissolved in 35.58 g of water was prepared.

  First, an unsaturated monomer (3) synthesized in Production Example 2 was added to a glass reactor equipped with a Dimroth condenser, a Teflon (registered trademark) stirring blade and a stirrer with a stirring seal, a nitrogen inlet tube, and a temperature sensor. (Unsaturated alcohol in which 50 moles of ethylene oxide was added to methyl-3-buten-1-ol on average) 48.49 g and 250.24 g of water were charged, and while stirring at 250 rpm, nitrogen was introduced at 100 to 200 mL / min. 58 Warmed to ° C. Next, the entire amount of the polymerization initiator aqueous solution was added to the reaction vessel and heated to 58 ° C. Next, an acrylic acid aqueous solution was dropped into the reaction vessel over 3 hours and an aqueous solution of the chain transfer agent over 3.5 hours, and then the temperature was maintained at 58 ° C. for 1 hour to complete the polymerization reaction, and the weight average molecular weight was 34,300. 999 g of a 55% aqueous solution of Polymer 1 was obtained.

≪Production Example 5≫
As an acrylic acid aqueous solution, an aqueous solution in which 64.64 g of acrylic acid was dissolved in 61.85 g of water was prepared. As an aqueous solution of a chain transfer agent, an aqueous solution was prepared by dissolving 2.14 g of 3-mercaptopropionic acid and 0.99 g of L-alcorbic acid in 96.87 g of water. As an aqueous solution of the polymerization initiator, an aqueous solution in which 2.54 g of 30% hydrogen peroxide was dissolved in 35.58 g of water was prepared.

  First, the unsaturated monomer (3) synthesized in Production Example 3 was added to a glass reaction vessel equipped with a Dimroth condenser, a Teflon (registered trademark) stirring blade and a stirrer with a stirring seal, a nitrogen inlet tube, and a temperature sensor. (Unsaturated alcohol in which 50 moles of ethylene oxide was added to methyl-3-buten-1-ol on average) 48.49 g and 250.24 g of water were charged, and while stirring at 250 rpm, nitrogen was introduced at 100 to 200 mL / min. 58 Warmed to ° C. Next, the entire amount of the polymerization initiator aqueous solution was added to the reaction vessel and heated to 58 ° C. Next, an aqueous acrylic acid solution was dropped into the reaction vessel over 3 hours and an aqueous solution of a chain transfer agent over 3.5 hours, and then the temperature was maintained at 58 ° C. for 1 hour to complete the polymerization reaction, resulting in a weight average molecular weight of 32,600. 999 g of a 55% aqueous solution of Polymer 2 was obtained.

≪Comparative Production Example 3≫
As an acrylic acid aqueous solution, an aqueous solution in which 64.64 g of acrylic acid was dissolved in 61.85 g of water was prepared. As an aqueous solution of a chain transfer agent, an aqueous solution was prepared by dissolving 2.14 g of 3-mercaptopropionic acid and 0.99 g of L-alcorbic acid in 96.87 g of water. As an aqueous solution of the polymerization initiator, an aqueous solution in which 2.54 g of 30% hydrogen peroxide was dissolved in 35.58 g of water was prepared.

  First, the unsaturated monomer synthesized in Comparative Production Example 2 was added to a glass reaction vessel equipped with a Dimroth condenser, a Teflon (registered trademark) stirring blade and a stirrer with a stirring seal, a nitrogen introduction tube, and a temperature sensor. (Unsaturated alcohol in which 50 mol of ethylene oxide is added to 3-methyl-3-buten-1-ol on average) 484.49 g and 250.24 g of water are charged, and while stirring at 250 rpm, nitrogen is introduced at 100 to 200 mL / min. Warmed to 58 ° C. Next, the entire amount of the polymerization initiator aqueous solution was added to the reaction vessel and heated to 58 ° C. Next, an aqueous acrylic acid solution was dropped into the reaction vessel over 3 hours and an aqueous solution of a chain transfer agent over 3.5 hours, and then the temperature was maintained at 58 ° C. for 1 hour to complete the polymerization reaction, resulting in a weight average molecular weight of 34,500. 999 g of a 55% aqueous solution of Comparative Polymer 1 was obtained.

  Next, a mortar test was performed using the polymers 1 and 2 of the present invention and the comparative polymer 1 synthesized in Production Examples 4 and 5 and Comparative Production Example 3.

<Mortar test>
(Contains mortar)
The mortar formulation was C / S / W = 550 / 1,350 / 220 (g). However,
C: Ordinary Portland cement (manufactured by Taiheiyo Cement)
S: ISO standard sand (made by Cement Association)
W: Sample ion exchange aqueous solution (mortar experimental environment)
The experimental environment was a temperature of 20 ° C. ± 1 ° C. and a relative humidity of 60% ± 10%.

(Mortar kneading, flow value measurement procedure)
A predetermined amount of the polymer aqueous solution was weighed, and 10 wt% of the antifoaming agent MA-404 (manufactured by Pozoris) was added to the polymer, and further ion-exchanged water was added to make 220 g, which was sufficiently uniformly dissolved. The mortar kneading procedure and the mortar flow value measuring procedure were based on JIS R5201 (1997). The mixer used was an N-50 mixer manufactured by HOBART with a stainless beater (stirring blade).

<Results of mortar test>
Table 1 shows the mortar test results of the polymers 1 and 2 and the comparative polymer 1 of the present invention.

  As is clear from Table 1, when the mortars to which the polymers 1 and 2 of the present invention and the comparative polymer 1 were added were compared at the same addition amount (0.09 wt% / C), the unsaturated unit having a high PEG content. The polymers 1 and 2 of the present invention polymerized using a monomer have a flow value immediately after that of the comparative polymer 1 and are excellent in initial dispersibility. In addition, the Δ flow value obtained by subtracting the immediately following flow value from the flow value after 30 minutes is also smaller in the polymers 1 and 2 of the present invention, indicating that the fluidity retention performance is also excellent. Furthermore, although the state of the mortar is also visually observed, the polymers 1 and 2 of the present invention have a better state with less mortar viscosity than the comparative polymer 1.

  Thus, using an unsaturated monomer containing a predetermined amount of polyethylene glycol or isoprene, compared to using an unsaturated monomer whose content of these impurities is outside the range of the predetermined amount, It can be seen that a mortar having excellent initial dispersibility and fluidity retention performance and having a low viscosity can be obtained.

≪Production Example 6≫
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, the unsaturated monomer synthesized in Production Example 2 (3-methyl-3-buten-1-ol was mixed with ethylene oxide). 50 mol of unsaturated alcohol) (49.37 g) and ion-exchanged water (25.48 g) were charged, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. 3.0 g was added and 4.08 g of 80% acrylic acid aqueous solution (monomer (b1)) was added dropwise over 1.5 hours. Following completion of the dropwise addition of monomer (b1), 80% aqueous acrylic acid solution was added. (Monomer (b2)) 1.92 g was added dropwise over 1.5 hours. At the same time as the monomer (b1) was added dropwise, an aqueous solution consisting of 0.16 g of 3-mercaptopropionic acid, 0.08 g of L-ascorbic acid, and 15.91 g of ion-exchanged water was added dropwise over 3.5 hours. Thereafter, the temperature was maintained at 60 ° C. for 1 hour, followed by cooling to complete the polymerization. Thereafter, the reaction solution was neutralized to pH 7.0 using a sodium hydroxide aqueous solution at a temperature lower than the polymerization reaction temperature (30 ° C.), and 120.4 g of a 45% aqueous solution of polymer 3 having a weight average molecular weight of 42,000 was obtained. Obtained.

≪Production Example 7≫
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube, and a reflux condenser, the unsaturated monomer synthesized in Production Example 3 (3-methyl-3-buten-1-ol was mixed with ethylene oxide). 50 mol of unsaturated alcohol) (49.37 g) and ion-exchanged water (25.48 g) were charged, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. 3.0 g was added, and 1.92 g of 80% acrylic acid (containing 0.1% by mass of β-acryloxypropanoic acid) aqueous solution (monomer (b1)) was added dropwise over 1.5 hours. Subsequent to the completion of dropping of the body (b1), 4.08 g of an 80% acrylic acid (containing 0.1% by mass of β-acryloxypropanoic acid) aqueous solution (monomer (b2)) was dropped over 1.5 hours. . At the same time as the monomer (b1) was added dropwise, an aqueous solution consisting of 0.16 g of 3-mercaptopropionic acid, 0.08 g of L-ascorbic acid, and 15.91 g of ion-exchanged water was added dropwise over 3.5 hours. Thereafter, the temperature was maintained at 60 ° C. for 1 hour, followed by cooling to complete the polymerization. Thereafter, the reaction solution was neutralized to pH 7.0 using a sodium hydroxide aqueous solution at a temperature not higher than the polymerization reaction temperature (30 ° C.), and 120.4 g of 45% aqueous solution of polymer 4 having a weight average molecular weight of 41,000 was obtained. Obtained.

≪Production Example 8≫
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, the unsaturated monomer synthesized in Production Example 3 (3-methyl-3-buten-1-ol was mixed with ethylene oxide). 50 mol of unsaturated alcohol) (49.37 g) and ion-exchanged water (25.48 g) were charged, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. 3.0 g was added, and 1.25 g of 80% acrylic acid (containing 2.0 mass% β-acryloxypropanoic acid) aqueous solution (monomer (b1)) was added dropwise over 1.5 hours. Subsequent to the completion of the dropwise addition of the body (b1), 4.75 g of an 80% acrylic acid (containing 2.0 mass% β-acryloxypropanoic acid) aqueous solution (monomer (b2)) was added dropwise over 1.5 hours. . At the same time as the monomer (b1) was added dropwise, an aqueous solution consisting of 0.16 g of 3-mercaptopropionic acid, 0.08 g of L-ascorbic acid, and 15.91 g of ion-exchanged water was added dropwise over 3.5 hours. Thereafter, the temperature was maintained at 60 ° C. for 1 hour, followed by cooling to complete the polymerization. Thereafter, the reaction solution was neutralized to pH 7.0 with a sodium hydroxide aqueous solution at a temperature not higher than the polymerization reaction temperature (30 ° C.), and 120.4 g of 45% aqueous solution of polymer 5 having a weight average molecular weight of 41,000 was obtained. Obtained.

≪Comparative Production Example 4≫
The unsaturated monomer (3-methyl-3-buten-1-ol and ethylene oxide synthesized in Comparative Production Example 2) was added to a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser. Is charged with 50 mol of unsaturated alcohol) and ion exchange water 25.48 g, and the reaction vessel is purged with nitrogen under stirring and heated to 60 ° C. in a nitrogen atmosphere. 3.0 g of an aqueous solution was added, and 1.92 g of an aqueous solution of 80% acrylic acid (containing 5.8% by mass of β-acryloxypropanoic acid) (monomer (b1)) was added dropwise over 1.5 hours. Following completion of the dropping of the monomer (b1), 4.08 g of an 80% acrylic acid (containing 5.8% by mass of β-acryloxypropanoic acid) aqueous solution (monomer (b2)) was dropped over 1.5 hours. did. At the same time as the monomer (b1) was added dropwise, an aqueous solution consisting of 0.16 g of 3-mercaptopropionic acid, 0.08 g of L-ascorbic acid, and 15.91 g of ion-exchanged water was added dropwise over 3.5 hours. Thereafter, the temperature was maintained at 60 ° C. for 1 hour, followed by cooling to complete the polymerization. Thereafter, the reaction solution was neutralized to pH 7.0 using a sodium hydroxide aqueous solution at a temperature not higher than the polymerization reaction temperature (30 ° C.), and 120.4 g of a 45% aqueous solution of comparative polymer 2 having a weight average molecular weight of 38,000. Got.

  Next, using the polymer 4 and the comparative polymer 2 of the present invention synthesized in Production Example 7 and Comparative Production Example 4, a mortar test was conducted in the same manner as described above. The mortar test results are shown in Table 2.

  As apparent from Table 2, acrylic acid containing 0.10 mass of β-acryloxypropanoic acid and unsaturated alcohol obtained by adding 50 mol of ethylene oxide to 3-methyl-3-buten-1-ol synthesized in Production Example 7 And an unsaturated alcohol obtained by adding 50 mol of ethylene oxide to 3-methyl-3-buten-1-ol synthesized in Comparative Production Example 2 and β-acryloxypropanoic acid. Comparing the mortar test results of the comparative polymer 2 polymerized using 5.8% by mass of acrylic acid (all the synthesis conditions other than the monomers used are the same), the polymer 4 of the present invention is kneaded. The flow value immediately after is excellent, and the Δ flow value obtained by subtracting the flow value immediately after kneading from the flow value after 30 minutes is also superior in the polymer 4 of the present invention.

  Thus, it is more preferable to use an unsaturated monomer containing a predetermined amount of polyethylene glycol or isoprene and an unsaturated carboxylic acid monomer having a (meth) acrylic acid dimer content of a predetermined amount or less. It can be seen that the initial dispersibility and fluidity retention performance are superior compared to the case of using an unsaturated monomer and an unsaturated carboxylic acid monomer whose impurity content is outside the predetermined range.

≪Production Example 9≫
As an acrylic acid aqueous solution, an aqueous solution in which 64.64 g of acrylic acid containing 0.10% by mass of β-acryloxypropanoic acid was dissolved in 61.85 g of water was prepared. As a chain transfer agent, an aqueous solution in which 2.14 g of 3-mercaptopropionic acid and 0.99 g of L-ascorbic acid were dissolved in 96.87 g of water was prepared. As an aqueous solution of the polymerization initiator, an aqueous solution in which 2.54 g of 30% hydrogen peroxide was dissolved in 35.58 g of water was prepared.

  In a glass reaction vessel equipped with a cooling tube, a stirrer, a nitrogen introducing tube, a thermometer, and a dropping funnel, the unsaturated monomer synthesized in Production Example 2 (3-methyl-3-buten-1-ol was mixed with 50 ethylene oxide). Mole-added unsaturated alcohol) 484.49 g and 250.24 g of water were charged, and the mixture was heated to 58 ° C. while stirring at 250 rpm and introducing nitrogen at 100 to 200 mL / min. Next, the entire amount of the polymerization initiator aqueous solution was added to the reaction vessel and heated to 58 ° C. Subsequently, an acrylic acid aqueous solution was dropped into the reaction vessel over 3 hours and an aqueous solution of a chain transfer agent over 3.5 hours, and then the temperature was maintained at 58 ° C. for 1 hour to complete the polymerization reaction, and the weight average molecular weight 34,000. 1,220 g of 45% aqueous solution of polymer 6 was obtained.

<< Production Examples 10-14 and Comparative Production Example 5 >>
Kind of unsaturated monomer (unsaturated alcohol in which 50 mol of ethylene oxide is added to 3-methyl-3-buten-1-ol), content of β-acryloxypropanoic acid (acrylic acid dimer) contained in acrylic acid Except having used the raw material which is a ratio as shown in following Table 3, it carried out similarly to manufacture example 9, and obtained 1,220 g of 45% aqueous solution of the polymers 7-11 and the comparison polymer 3.

  Using the polymers 6, 8, 10 of the present invention synthesized in Production Examples 9, 11, 13 and Comparative Production Example 5 and Comparative Polymer 3, a mortar test was conducted in the same manner as described above. The mortar test results are shown in Table 4.

  As is clear from Table 4, an acrylic containing 0.10% by mass of unsaturated alcohol obtained by adding 50 moles of ethylene oxide to 3-methyl-3-buten-1-ol synthesized in Production Example 2 and β-acryloxypropanoic acid. Polymer 6 of the present invention polymerized with an acid, 4-methyl-3-buten-1-ol synthesized in Production Example 2 added with 50 mol of ethylene oxide and β-acryloxypropanoic acid 4 Polymer 8 of the present invention polymerized using 1% by mass of acrylic acid, unsaturated alcohol obtained by adding 50 mol of ethylene oxide to 3-methyl-3-buten-1-ol synthesized in Production Example 3, and β- Polymer 10 of the present invention polymerized using acrylic acid containing 2.0% by mass of acryloxypropanoic acid, and 3-methyl-3-butene-1- synthesized in Comparative Production Example 2 Comparative polymer 3 polymerized using an unsaturated alcohol in which 50 mol of ethylene oxide was added to the alcohol and acrylic acid containing 5.8% by mass of β-acryloxypropanoic acid (all synthesis conditions other than the monomers used were When the mortar test results were compared with the same, all of the polymers 6, 8 and 10 of the present invention were excellent in the flow value immediately after kneading, and the Δ flow value obtained by subtracting the flow value immediately after kneading from the flow value after 30 minutes. All of the polymers 6, 8 and 10 of the present invention are superior.

  Thus, it is more preferable to use an unsaturated monomer containing a predetermined amount of polyethylene glycol or isoprene and an unsaturated carboxylic acid monomer having a (meth) acrylic acid dimer content of a predetermined amount or less. It can be seen that the initial dispersibility and fluidity retention performance are superior compared to the case of using an unsaturated monomer and an unsaturated carboxylic acid monomer whose impurity content is outside the predetermined range.

≪Production Example 15≫
Into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser, 50 moles of the unsaturated monomer synthesized in Production Example 3 (3-methyl-3-buten-1-ol was added in an amount of 50 mol). (Unsaturated alcohol) 127.74 g and ion-exchanged water 72.26 g were charged and the temperature was raised to 60 ° C., followed by addition of 0.68 g of 30% aqueous hydrogen peroxide solution, 8.82 g of acrylic acid and 14.28 g of hydroxyethyl acrylate Was added dropwise over 3 hours, and an aqueous solution prepared by mixing 0.82 g of 3-mercaptopropionic acid, 0.27 g of L-ascorbic acid and 26.63 g of ion-exchanged water over 3.5 hours. Thereafter, the temperature was kept at 60 ° C. for 1 hour to complete the polymerization reaction, the temperature was lowered to 50 ° C. or less, neutralized to pH 7.0 with an aqueous sodium hydroxide solution, and a weight average molecular weight of 29,800 was obtained. 335 g of a 45% aqueous solution of coalescence 12 was obtained.

  The present invention further improves the dispersion performance of inorganic substances and gives a good state to mortars, and also disperses various powders, such as cement admixtures, organic and inorganic pigment dispersants, scale prevention. Copolymers with polyalkylene glycol chains that are useful as detergents, detergent builders, used paper recycling deinking agents, chelating agents, dispersants for various dyes, agricultural chemical dispersants, fine cotton detergents, coal dispersants, etc. Production method and unsaturated monomer used as a raw material for such a copolymer, it contributes greatly in the fields of civil engineering and construction, as well as various applications of water-soluble resins. It is what you make.

Claims (8)

Following formula (1):

[Wherein, R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and AO represents 2 carbon atoms. -18 represents an oxyalkylene group, n represents the average number of moles added of the oxyalkylene group, represents a number of 1 to 300, and when n is 2 or more, a plurality of AOs are the same or different. X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1.]
A method for producing a copolymer having a polyalkylene glycol chain by polymerizing a monomer component containing an unsaturated polyalkylene glycol ether monomer and an unsaturated monocarboxylic acid monomer represented by An unsaturated polyalkylene glycol ether monomer containing 1 to 20% by mass of polyalkylene glycol is used as at least a part of the unsaturated polyalkylene glycol ether monomer. A production method using 10% by mass or more based on the total amount.   The production method according to claim 1, wherein an unsaturated polyalkylene glycol ether monomer containing 100 to 10,000 ppm of isoprene on a mass basis is used as at least a part of the unsaturated polyalkylene glycol ether monomer.   The unsaturated monocarboxylic acid monomer is a monomer containing a (meth) acrylic acid monomer, and the (meth) acrylic acid dimer content in the (meth) acrylic acid monomer is The production method according to claim 1, wherein the content is 5% by mass or less based on the (meth) acrylic acid monomer.   The production method according to claim 1, wherein the copolymer is a copolymer for cement admixture. Following formula (2):

[Wherein R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1]
By adding an alkylene oxide to the unsaturated alcohol represented by the following formula (1):

[Wherein, R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and AO represents 2 carbon atoms. -18 represents an oxyalkylene group, n represents the average number of moles added of the oxyalkylene group, represents a number of 1 to 300, and when n is 2 or more, a plurality of AOs are the same or different. X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1.]
A method for producing an unsaturated polyalkylene glycol ether monomer represented by the formula (1), wherein an unsaturated alcohol containing 100 to 10,000 ppm of water on a mass basis is used as at least a part of the unsaturated alcohol. A featured manufacturing method. Following formula (2):

[Wherein R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1]
By adding an alkylene oxide to the unsaturated alcohol represented by the following formula (1):

[Wherein, R ¹ , R ² and R ³ independently represent a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and AO represents 2 carbon atoms. -18 represents an oxyalkylene group, n represents the average number of moles added of the oxyalkylene group, represents a number of 1 to 300, and when n is 2 or more, a plurality of AOs are the same or different. X represents an alkylene group having 1 to 6 carbon atoms, and m is 0 or 1.]
The unsaturated polyalkylene glycol ether monomer represented by the formula (1) is produced, and the monomer component containing the unsaturated polyalkylene glycol ether monomer and the unsaturated monocarboxylic acid monomer is polymerized. To produce a copolymer having a polyalkylene glycol chain, wherein as the at least part of the unsaturated alcohol, an unsaturated alcohol containing 100 to 10,000 ppm of water on a mass basis is used, and the unsaturated alcohol is used. As at least a part of the saturated polyalkylene glycol ether monomer, an unsaturated polyalkylene glycol ether monomer containing 1 to 20% by mass of polyalkylene glycol, with respect to the total amount of the monomer components, A production method using 10% by mass or more.   The production method according to claim 6, wherein the copolymer is a copolymer for cement admixture.   An unsaturated polyalkylene glycol ether monomer obtained by the production method according to claim 5.