JP5866098B2 - Carboxyl group-containing copolymer and method for producing the same - Google Patents

Description

The present invention relates to a carboxyl group-containing copolymer and a method for producing the same.

In a cooling water system, a boiler water system, a seawater desalination apparatus, a pulp dissolving kettle, a black liquor concentration kettle, etc., hardness components and the like contained in water are combined with silica components and the like to generate scale. When the scale is deposited on the inner wall, various operational obstacles such as a decrease in thermal efficiency and local corrosion may occur.
Therefore, conventionally, a scale inhibitor using sodium polyacrylate or the like is known (for example, Patent Document 1). Patent Document 1 discloses that the inhibitory effect on scale generation of the scale inhibitor is presumed to be mainly caused by a dispersing action.

  For example, in Cited Document 1, the structural unit (a) derived from the (meth) acrylic acid monomer (A) represented by the following formula (R-1) and the following formula (R-2) are represented. A structural unit (b) derived from the sulfonic acid monomer (B) and a structural unit (c) derived from the (meth) acrylic acid monomer (C) represented by the following formula (R-3): An anti-scale agent comprising a (meth) acrylic acid-based polymer having

(In formula (R-1), R ¹ represents a hydrogen atom or a methyl group, and X represents a hydrogen atom, a metal atom, an ammonium group, an organic ammonium group, or an organic amino group.)

(In Formula (R-2), R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or a methyl group; p represents 0 or 1; and R ⁵ represents —CH ₂ —, — _{CH 2 -CH 2 -, - CH} 2 -O-CH 2 -, - CO-O-CH 2 -CH 2 - or _{-CO-NH-C (CH 3} ), 2 - , Y represents the -SO ₃ X or —CHR ⁶ —CH ₂ R ⁷ , wherein R ⁶ and R ⁷ are the same or different and represent —OH or —SO ₃ X, and at least one of R ⁶ and R ⁷ is —SO ₃ X , X represents a hydrogen atom, a metal atom, an ammonium group, an organic ammonium group, or an organic amino group.)

(In formula (R-3), R ⁸ represents a hydrogen atom, a methyl group, a hydroxymethyl group, or a hydroxyethyl group, R ⁹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁸ represents hydrogen. In the case of an atom or a methyl group, R ⁹ is not a hydrogen atom.)
Cited Document 1 discloses that the scale inhibitor has an excellent ability to prevent scale against calcium phosphate, and that the (meth) acrylic acid polymer is useful as such a scale inhibitor.

JP 2009-28618 A

As described above, although various polymers have been reported in the past, there is room for improving the scale prevention effect, particularly the scale prevention effect for silica scale.
Therefore, the present invention provides a polymer that can be preferably used as a scale inhibitor for silica scale by using a silica scale having better dispersibility than ever when used in water treatment. Objective.

As a result of intensive studies on various polymers (including copolymers) in order to achieve the above object, the present inventors have found that a structural unit derived from a specific ether bond-containing monomer and a carboxyl group It has been found that a copolymer in which a structural unit derived from a monomer is introduced at a specific ratio has an excellent silica scale dispersibility and can be usefully used as a scale inhibitor for silica scale. Based on the above findings, the present invention has been completed.
That is, the present invention relates to a structural unit (a) derived from an ether bond-containing monomer (A) represented by the following general formula (1) of 1% by mass or more and 49% by mass or less, 51% by mass or more, 99% It is the carboxyl group-containing copolymer which has as a structural unit (b) essential structural unit derived from the carboxyl group-containing monomer (B) of the mass% or less.

In the general formula (1), R ₀ represents a hydrogen atom or a CH ₃ group, R ₁ represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond, and R ₂ is the same or different and has a carbon number Represents an alkylene group having 3 to 6, n represents an average addition mole number of an oxyalkylene group (—R ₂ —O—), represents a number of 1 to 5, and R ₃ represents a hydrogen atom or a carbon number of 1; Represents an organic group of ˜7.

The carboxyl group-containing copolymer of the present invention has an excellent silica scale dispersibility. Therefore, for example, it can be usefully used as a scale inhibitor for silica scale.

Hereinafter, the present invention will be described in detail.

[Carboxyl group-containing copolymer of the present invention]
<Ether bond-containing monomer as monomer (A)>
The carboxyl group-containing copolymer of the present invention is required to have the structural unit (a) derived from the ether bond-containing monomer (A) represented by the following general formula (1) at a specific ratio.

In the general formula (1), R ₀ represents a hydrogen atom or a CH ₃ group, R ₁ represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond, and R ₂ is the same or different and has a carbon number Represents an alkylene group having 3 to 6, n represents an average addition mole number of an oxyalkylene group (—R ₂ —O—), represents a number of 1 to 5, and R ₃ represents a hydrogen atom or a carbon number of 1; Represents an organic group of ˜7.

In the general formula (1), R ₁ represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond, and these groups tend to improve the dispersibility of silica scale. In addition, because hydrolysis resistance is superior compared to carbonyl groups and amide groups, for example, decomposition is suppressed even under heating conditions such as during polymerization and during the manufacture of various products including polymers. , Improving the quality of the product used (less variation).
R ₁ is preferably a CH ₂ group or a CH ₂ CH ₂ group because the resulting copolymer has a higher effect of improving the dispersibility of silica scale.
In the general formula (1), R ₀ is preferably a CH ₃ group because the effect of improving the silica scale dispersibility of the obtained copolymer tends to be high.

R ₂ is the same or different and represents an alkylene group having 3 to 6 carbon atoms. Specific examples of the alkylene group having 3 to 6 carbon atoms include a —CH ₂ (CH ₃ ) CH ₂ — group and —CH _2. Examples include ₂ (C ₂ H ₅ ) CH ₂ — group, —CH ₂ (C ₃ H ₇ ) CH ₂ — group, —CH ₂ (C ₄ H ₉ ) CH ₂ — group, cyclohexene group and the like.
R ₂ is preferably the same or different and represents an alkylene group having 4 to 6 carbon atoms.

n is the average number of added moles of the oxyalkylene group (—R ₂ —O—) and represents a number of 1 to 5, and the effect of improving the silica scale dispersibility of the obtained copolymer is higher. Therefore, n is preferably a number of 1 to 3, and particularly preferably 1 or 2.

As described above, R ₃ is a hydrogen atom or an organic group having 1 to 7 carbon atoms. When R ₃ is an organic group having 1 to 7 carbon atoms, R ₃ is an amino group, an amide group, a hydroxyl group, It may contain a functional group such as an alkoxide group, a sulfonic acid group, a carbonyl group, or a carboxyl group, and may contain an ether bond, sulfide bond, ester bond, or amide bond. However, it is preferable that R ₃ does not contain a hetero atom because the effect of improving the silica scale dispersibility of the obtained copolymer tends to be high. Examples of the organic group include substituted or unsubstituted alkyl groups, aryl groups, and alkenyl groups. The substituted alkyl group, aryl group, and alkenyl group represent a group in which some or all of the hydrogen atoms of the alkyl group, aryl group, or alkenyl group are substituted with a functional group such as the above functional group. .

The R ₃ where the R ₃ is an organic group having 1 to 7 carbon atoms, such as methyl group, isopropyl group, n- propyl group, n- butyl group, isobutyl group, tertiary butyl group, butylene Group, phenyl group, methylphenyl group and the like.
R ₃ is preferably a hydrogen atom or an organic group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an organic group having 1 to 2 carbon atoms, and particularly preferably a hydrogen atom.

The ether bond-containing monomer (A) represented by the general formula (1) is, for example, 1 to 5 mol with respect to 1 mol of unsaturated alcohol such as allyl alcohol, methallyl alcohol, isoprenol, and vinylhydroxybutyl ether. It can manufacture by adding C3-C6 alkylene oxide.
Examples of the alkylene oxide having 3 to 6 carbon atoms include propylene oxide, butylene oxide, pentene oxide, hexene oxide, and cyclohexene oxide. When two or more kinds of alkylene oxide are added, they may be added to the block or randomly.
The method for adding alkylene oxide to unsaturated alcohol is not particularly limited. (I) Anionic polymerization using strong alkali such as alkali metal hydroxide or alcoholate, alkylamine or the like as a base catalyst, (ii) metal And cationic polymerization using metalloid halides, mineral acids, acetic acid and the like as catalysts, and (iii) coordination polymerization using a combination of metal alkoxides such as aluminum, iron and zinc, alkaline earth compounds, Lewis acids, etc. Etc. can be used.
After adding an alkylene oxide to an unsaturated alcohol, an alkyl group may be introduced at the terminal by reacting an alkyl halide or the like with the terminal hydroxyl group.

The structural unit (a) is a monomer (A), that is, in the above formula (1), a polymerizable unsaturated double bond (CH ₂ ═C (R ₁ ) —) is a single bond (—CH ₂ —). C (R ₁ )-), which is represented by the following general formula (2).

In the general formula (2), R ₀ represents a hydrogen atom or a CH ₃ group, R ₁ represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond, and R ₂ is the same or different and has a carbon number Represents an alkylene group having 3 to 6, n represents an average addition mole number of an oxyalkylene group (—R ₂ —O—), represents a number of 1 to 5, and R ₃ represents a hydrogen atom or a carbon number of 1; Represents an organic group of ˜7.
The carboxyl group-containing copolymer of the present invention may contain only one type of structural unit (a), but may contain two or more types.

  The carboxyl group-containing copolymer of the present invention comprises all structural monomers (ether bond-containing monomers) derived from the ether bond-containing monomer (A) represented by the general formula (1). (A), the sum of structural units derived from the carboxyl group-containing monomer (B) and other monomers (E) described later (ie, the structural unit (a), the structural unit (b), the structural unit ( It is essential to have a ratio of 1% by mass to 49% by mass with respect to 100% by mass of e). When the structural unit (a) is within the above range, the silica scale dispersibility of the copolymer tends to be improved. The ratio of the structural unit (a) to the total of 100% by mass of the structural units derived from all monomers is preferably 1% by mass or more and 39% by mass or less, more preferably 2% by mass or more and 29% by mass or less. More preferably, it is 3% by mass or more and 25% by mass or less, and particularly preferably 4% by mass or more and 19% by mass or less.

<Carboxyl group-containing monomer (B)>
The carboxyl group-containing copolymer of the present invention is required to have the structural unit (b) derived from the carboxyl group-containing monomer (B) at a specific ratio.
In the present invention, the carboxyl group-containing monomer (B) is a monomer that essentially contains 1) a carbon-carbon unsaturated double bond and 2) a carboxyl group and / or a salt thereof (provided that the monomer is used). The monomer belonging to (A) is excluded from the monomer (B)). Specifically, unsaturated monocarboxylic acids and their salts such as acrylic acid, methacrylic acid, crotonic acid, α-hydroxyacrylic acid, α-hydroxymethylacrylic acid and derivatives thereof; itaconic acid, fumaric acid, malee Examples thereof include unsaturated dicarboxylic acids such as acid and 2-methyleneglutaric acid, and salts thereof.

  The salt is a metal salt, an ammonium salt, or an organic amine salt. Examples of the metal salt include alkali metal salts such as sodium salt, lithium salt and potassium salt; alkaline earth metal salts such as magnesium salt and calcium salt; salts such as aluminum and iron. Organic amine salts include monoethanolamine salts, diethanolamine salts, triethanolamine salts and other alkanolamine salts; monoethylamine salts, diethylamine salts, triethylamine salts and other alkylamine salts; ethylenediamine salts, triethylenediamine salts and other polyamines And salts of organic amines such as Among the salts, alkali metal salts such as sodium and potassium are preferred because the silica scale dispersibility tends to be improved.

Among the carboxyl group-containing monomers (B), acrylic acid, acrylate, maleic acid, and maleate are preferred because of the high effect of improving the silica scale dispersibility of the copolymer, and acrylic acid and / or More preferably, acrylate is essential.
The copolymer of the present invention may contain only one type of structural unit (b), but may contain two or more types.
The structural unit (b) has a structure in which the carbon-carbon unsaturated double bond of the monomer (B) is a single bond. For example, when the monomer (B) is represented by CH ₂ ═C (COOH) —, the structural unit (b) is represented by —CH ₂ —C (COOH) —.

  In the carboxyl group-containing copolymer of the present invention, the structural unit (b) derived from the carboxyl group-containing monomer (B) is 51% by mass or more with respect to 100% by mass in total of the structural units derived from all monomers. , 99% by mass or less is essential. When the structural unit (b) is within the above range, the silica scale dispersibility tends to be improved. The ratio of the structural unit (b) to the total of 100 mass% of the structural units derived from all monomers is preferably 61 mass% or more and 99 mass% or less, more preferably 71 mass% or more and 98 mass% or less. More preferably, they are 75 mass% or more and 97 mass% or less, Most preferably, they are 81 mass% or more and 96 mass% or less.

In addition, in this invention, when calculating the mass ratio (mass%) with respect to the sum total of the structural unit derived from all the monomers of the structural unit (b) derived from a carboxyl group-containing monomer (B), a corresponding acid It shall be calculated as a conversion. When calculated as acid conversion, for example, if the structural unit is —CH ₂ —CH (COONa) — derived from sodium acrylate, then the structural unit derived from acrylic acid which is the corresponding acid —CH ₂ —CH (COOH) — Calculate the mass ratio (mass%). Similarly, also when calculating the mass ratio (mass%) with respect to all the monomers of a carboxyl group-containing monomer (B), it shall calculate as a corresponding acid conversion. For example, if it is sodium acrylate, a mass ratio (mass%) is calculated as acrylic acid which is a corresponding acid.
Furthermore, the mass ratio (% by mass) of the structural unit derived from all monomers of the structural unit derived from the acid group-containing monomer other than the carboxyl group-containing monomer (B) (for example, sulfonic acid group-containing monomer). When calculating the mass ratio (% by mass) with respect to all monomers of the acid group-containing monomer other than the carboxyl group-containing monomer (B) Is also calculated as the corresponding acid equivalent. Moreover, the structural unit derived from an amino group-containing monomer and the amino group-containing monomer are mass-calculated as a corresponding structural unit derived from an unneutralized amine and an unneutralized amine. For example, in the case of vinylamine hydrochloride, the mass ratio (% by mass) is calculated as vinylamine which is the corresponding unneutralized amine.

<Other monomers>
The carboxyl group-containing copolymer of the present invention may have a structural unit (e) derived from another monomer (E).
As the other monomer (E) when the carboxyl group-containing copolymer of the present invention contains another monomer (E), one or more of the above monomers (A) and (B) are used. The copolymer is not particularly limited as long as it can be copolymerized with A, and is appropriately selected depending on the desired effect. Specifically, sulfonic acid group-containing monomers such as 3-allyloxy-2-hydroxypropanesulfonic acid, (meth) allylsulfonic acid, isoprenesulfonic acid, vinylsulfonic acid, styrenesulfonic acid, and salts thereof; N- N-vinyl monomers such as vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, N-vinyl-N-methylformamide, N-vinyl-N-methylacetamide, N-vinyloxazolidone; (meth) acrylamide, N Amide monomers such as N, dimethylacrylamide and N-isopropylacrylamide; alkyl (meth) acrylate monomers such as butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and dodecyl (meth) acrylate ; 2-hydroxyethyl (meth) acrylate (Meth) such as 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypentyl (meth) acrylate, etc. Hydroxyalkyl acrylate monomers; vinyl aromatic amino group-containing monomers having a heterocyclic aromatic hydrocarbon group and a polymerizable group, such as vinylpyridine and vinylimidazole, and quaternized products and salts thereof; diallylamine Allylamines such as diallyldimethylamine and quaternized compounds and salts thereof; (i) (meth) allyl glycidyl ether, isoprenyl glycidyl ether, vinyl glycidyl ether on the epoxy ring; (ii) dimethylamine, diethylamine, diisopropylamine , Monomers obtained by reacting alkylamines such as n-butylamine, alkanolamines such as diethanolamine and diisopropanolamine, and cyclic amines such as morpholine and pyrrole, and quaternized compounds and salts thereof; styrene; , Vinyl aryl monomers such as indene and vinylaniline, isobutylene, and vinyl acetate.
Moreover, the said other monomer (E) may be used individually by 1 type, or may be used with the form of a 2 or more types of mixture.

The carboxyl group-containing copolymer of the present invention is optional, but the structural unit (e) is 0% by mass or more and 40% by mass or less with respect to 100% by mass in total of the structural units derived from all monomers. You may have in a ratio. The ratio of the structural unit (e) to the total of 100% by mass of the structural units derived from all monomers is preferably 0% by mass or more and 20% by mass or less, more preferably 0% by mass or more and 10% by mass or less. It is.
In the carboxyl group-containing copolymer of the present invention, the structural units (a) and (b) and, if necessary, the structural unit (e) may be introduced at a specific ratio as described above. The unit may exist in a block form or a random form. Moreover, the weight average molecular weight of the carboxyl group-containing copolymer of the present invention can be appropriately set and is not particularly limited. Specifically, the weight average molecular weight of the carboxyl group-containing copolymer is preferably 2,000 to 200,000, more preferably 3,000 to 60,000, and most preferably 4,000 to 30, 000. When the weight average molecular weight is within the above range, the dispersibility of silica scale tends to be improved. In addition, in this specification, a weight average molecular weight is a measured value by GPC (gel permeation chromatography), and was measured according to the method described in an Example.

[Carboxyl group-containing copolymer composition of the present invention (also simply referred to as polymer composition)]
The carboxyl group-containing copolymer composition of the present invention contains the carboxyl group-containing copolymer of the present invention as an essential component, and components other than the carboxyl group-containing copolymer are optional. Contains one or more selected from agent residues, residual monomers, by-products during polymerization, and moisture. The form of a preferable carboxyl group-containing copolymer composition is a form containing 20 to 80% by mass of a carboxyl group-containing copolymer and 20 to 80% by mass of water.
In the polymer composition of the present invention, the total amount of residual monomers is preferably 0 to 15000 ppm, more preferably 0 to 10,000 ppm, in terms of solid content of the polymer composition.

[Production method of carboxyl group-containing copolymer of the present invention]
As long as there is no notice in particular, the manufacturing method of the carboxyl group-containing copolymer of this invention can use the method which carried out similarly or modified the well-known polymerization method. As a method for producing the carboxyl group-containing copolymer of the present invention, an ether bond-containing monomer (A) and a monomer (monomer component) containing the carboxyl group-containing monomer (B) as essential components are used. It can manufacture by including the process to superpose | polymerize (polymerization process) essential. Moreover, when copolymerizing a monomer component, you may further copolymerize the said other monomer (E) as needed.

  In such a production method, the monomer component may be copolymerized using a polymerization initiator. In addition, the kind and usage-amount of the monomer contained in a monomer component are set suitably so that the structural unit which comprises a carboxyl group-containing copolymer may become as above-mentioned. That is, the composition ratio of each monomer forming the carboxyl group-containing copolymer is such that all monomers (that is, the ether bond-containing monomer (A), the carboxyl group-containing monomer (B) and other single monomers are included. The ether bond-containing monomer (A) is 1% by mass to 49% by mass and the carboxyl group-containing monomer (B) is 51% by mass to 99% by mass with respect to the monomer (E). As described above, when the total amount of all the other monomers (E) copolymerizable therewith is 100% by mass, the amount is 0% by mass or more and 40% by mass or less. Preferably, the ether bond-containing monomer (A) is 1% by mass to 39% by mass, the carboxyl group-containing monomer (B) is 61% by mass to 99% by mass, The other monomer (E) is 0% by mass or more and 20% by mass or less, More preferably, the ether bond-containing monomer (A) is 2 to 29% by mass, the carboxyl group-containing monomer (B) is 71 to 98% by mass, and other monomers ( E) is 0% by mass or more and 15% by mass or less, and more preferably, the ether bond-containing monomer (A) is 3% by mass or more and 25% by mass or less, and the carboxyl group-containing monomer (B) is 75%. The amount of the other monomer (E) is 0% by mass or more and 10% by mass or less, and particularly preferably the ether bond-containing monomer (A) is 4% by mass or more, 19% by mass or more and 97% by mass or less. % By mass or less, the carboxyl group-containing monomer (B) is 81% by mass or more and 96% by mass or less, and the other monomer (E) is 0% by mass or more and 8% by mass or less. The total amount of the bodies (A), (B), and (E) is 100% by mass.

  In the present invention, the copolymerization of the monomers (A) and (B) and, if necessary, another monomer (E) is a method and / or chain using water in 50% by mass or more of the solvent used. The method is preferably carried out in the presence of a transfer agent, more preferably 50% by weight or more of the solvent used and water in the presence of a chain transfer agent. At this time, by using water in 50% by mass or more of the solvent to be used, the amount of the organic solvent used for the polymerization can be suppressed, so that there is an advantage that the organic solvent can be easily distilled off after the completion of the polymerization. Moreover, when a chain transfer agent is used, it is possible to suppress the carboxyl group-containing copolymer to be produced from being unnecessarily high in molecular weight and to efficiently produce a low molecular weight carboxyl group-containing copolymer. There is. In particular, when bisulfite (salt) is used as a chain transfer agent, a sulfonic acid group can be introduced into the main chain terminal of the resulting carboxyl group-containing copolymer, and the dispersibility of silica scale can be improved. Therefore, it is preferable.

  Although it does not restrict | limit especially as a solvent used with the manufacturing method of this invention, As above-mentioned, what contains water in the ratio of 50 mass% with respect to the solvent whole quantity to be used is preferable. From the viewpoint of improving the solubility of the monomer used for polymerization in a solvent, an organic solvent may be added as necessary. Examples of the organic solvent that can be used include lower alcohols such as methanol, ethanol, and isopropyl alcohol; lower ketones such as acetone, methyl ethyl ketone, and diethyl ketone; ethers such as dimethyl ether and dioxane; amides such as dimethylformaldehyde. . These solvents may be used alone or in the form of a mixture of two or more. In the present invention, the amount of water is preferably 80% by mass or more, and most preferably water alone (ie, 100% by mass) with respect to the total amount of solvent used.

  As the usage-amount of the said solvent, 40-200 mass% is preferable with respect to a total of 100 mass% of all the monomers. More preferably, it is 45 mass% or more, More preferably, it is 50 mass% or more. Moreover, More preferably, it is 180 mass% or less, More preferably, it is 150 mass% or less. When the amount of the solvent used is 40% by mass or less, the molecular weight of the obtained copolymer may be increased. When the amount exceeds 200% by mass, the concentration of the obtained copolymer is decreased, and the solvent needs to be removed. There is a risk.

  As the initiator used in the method for producing a carboxyl group-containing copolymer of the present invention, known initiators can be used. Examples of the initiator include hydrogen peroxide; sodium persulfate, potassium persulfate, ammonium persulfate and the like. Sulfate; 2,2′-azobis (2-amidinopropane) hydrochloride, 4,4′-azobis-4-cyanoparerenic acid, azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2, Preferred are azo compounds such as 4-dimethylvaleronitrile); organic peroxides such as benzoyl peroxide, lauroyl peroxide, peracetic acid, di-t-butyl peroxide and cumene hydroperoxide. Of these polymerization initiators, hydrogen peroxide and persulfate are preferable, and the residual monomer can be reduced, and persulfate is most preferable. These polymerization initiators may be used alone or in the form of a mixture of two or more.

  The amount of the initiator used is not particularly limited as long as it is an amount capable of initiating copolymerization of the monomers (A) and (B) and, if necessary, other monomers (E). It is preferable that it is 10 g or less, more preferably 1 to 5 g with respect to 1 mol of all monomer components consisting of A), (B) and other monomer (E) if necessary.

In the production method of the present invention, the copolymerization is preferably performed in the presence of a chain transfer agent. The chain transfer agent that can be used in this case is not particularly limited as long as it is a compound capable of adjusting the molecular weight, and a known chain transfer agent can be used. Specifically, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropion, 3-mercaptopropion, thiomalic acid, octyl thioglycolate, octyl 3-mercaptopropionate, 2-mercaptoethanesulfonic acid, n -Thiol chain transfer agents such as dodecyl mercaptan, octyl mercaptan, butylthioglycolate; Halides such as carbon tetrachloride, methylene chloride, bromoform, bromotrichloroethane; Secondary alcohols such as isopropanol, glycerin; Acids, hypophosphorous acid and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, bisulfite, dithionite, metabisulfite, sulfite, thiosulfate ( Sodium hydrogen sulfite, potassium hydrogen sulfite, Sodium dithionite, potassium dithionite, sodium metabisulfite, metabisulfite potassium, etc.) and the like, and the like lower oxides and salts thereof. The chain transfer agent may be used alone or in the form of a mixture of two or more.
Among these, in the copolymerization reaction according to the present invention, it is preferable to use bisulfite (salt) (including a compound that produces a sulfite by hydrolysis like metabisulfite). As a result, a sulfonic acid group can be introduced into the main chain terminal of the resulting carboxyl group-containing copolymer, and the gel resistance can be improved. Moreover, it will be suppressed that the obtained copolymer becomes high molecular weight more than necessary.
The salt in the bisulfite (salt) is a metal salt, an ammonium salt, or an organic amine salt. Among the bisulfites (salts), sodium bisulfite and potassium bisulfite are preferable. Bisulfite (salt) may use only 1 type and may use 2 or more types.

  In the method for producing a carboxyl group-containing copolymer of the present invention, the amount of chain transfer agent used is preferably the total amount of monomer (A), (B) and, if necessary, the other monomer (E). It is 1-20g with respect to 1 mol of usage-amounts of a monomer, More preferably, it is 2-15g. If it is 1 g or less, the molecular weight may not be controlled. Conversely, if it exceeds 20 g, a large amount of impurities may be generated and the polymer content may be lowered. In particular, bisulfite (salt) is used. In some cases, surplus bisulfite (salt) is decomposed in the reaction system, and sulfurous acid gas may be generated. Moreover, there is a risk that it may be economically disadvantageous.

In the method for producing a carboxyl group-containing copolymer of the present invention, heavy metal ions may be used as a reaction accelerator. In the present invention, the heavy metal means a metal having a specific gravity of 4 g / cm ³ or more. As said metal ion, iron, cobalt, manganese, chromium, molybdenum, tungsten, copper, silver, gold, lead, platinum, iridium, osmium, palladium, rhodium, ruthenium etc. are preferable, for example. These heavy metals can be used alone or in combination of two or more. Among these, iron is more preferable. The ionic valence of the heavy metal ions is not particularly limited. For example, when iron is used as the heavy metal, the iron ions in the initiator may be Fe ²⁺ or Fe ³⁺ , and these may be combined. May be.

The heavy metal ions are not particularly limited as long as they are included in the form of ions. However, it is preferable to use a method using a solution in which a heavy metal compound is dissolved because the handleability is excellent. The heavy metal compound used in that case should just contain the heavy metal ion desired to contain in an initiator, and can be determined according to the initiator to be used. When iron is used as the heavy metal ion, the mole salt (Fe (NH ₄ ) ₂ (SO ₄ ) ₂ · 6H ₂ O), ferrous sulfate · 7 hydrate, ferrous chloride, ferric chloride, etc. It is preferable to use a heavy metal compound or the like. Moreover, when using manganese as a heavy metal ion, manganese chloride etc. can be used suitably. In the case of using these heavy metal compounds, since they are water-soluble compounds, they can be used in the form of an aqueous solution and have excellent handleability. The solvent of the solution obtained by dissolving the heavy metal compound is not limited to water, and does not hinder the polymerization reaction in the production of the carboxyl group-containing copolymer of the present invention, and is a heavy metal compound. As long as it dissolves.

  In the polymerization step in the present invention, the amount of heavy metal ions in the case of using the above heavy metal ions, it is preferable that a catalyst amount is included. The amount of catalyst referred to in the present specification means that the catalyst acts as a catalyst rather than being incorporated into the final target product. Specifically, it is 100 ppm or less, preferably 10 ppm or less, more preferably 5 ppm. It is as follows.

  The content of the heavy metal ions is preferably 0.1 to 10 ppm with respect to the total mass of the polymerization reaction solution at the completion of the polymerization reaction. If the content of heavy metal ions is 0.1 ppm or less, the effects of heavy metal ions may not be sufficiently exhibited. On the other hand, if the content of heavy metal ions exceeds 10 ppm, the color tone of the resulting polymer may be deteriorated.

  The time when the polymerization reaction is completed means the time when the polymerization reaction is substantially completed in the polymerization reaction solution and a desired polymer is obtained. For example, when the polymer polymerized in the polymerization reaction solution is neutralized with an alkali component, the content of heavy metal ions is calculated based on the total mass of the polymerization reaction solution after neutralization. When two or more kinds of heavy metal ions are included, the total amount of heavy metal ions may be in the above range.

  As described above, the combination of the initiator and the chain transfer agent is most preferably one or more of persulfate and bisulfite (salt). In this case, the mixing ratio of persulfate and bisulfite (salt) is not particularly limited, but it is preferable to use 0.5 to 5 parts by mass of bisulfite (salt) with respect to 1 part by mass of persulfate. . More preferably, the lower limit of bisulfurous acid (salt) is 1 part by mass, and most preferably 2 parts by mass with respect to 1 part by mass of persulfate. Moreover, the upper limit of bisulfite (salt) is more preferably 4 parts by mass, and most preferably 3 parts by mass with respect to 1 part by mass of persulfate. Here, if the bisulfurous acid (salt) is 0.5 parts by mass or less, the total amount of initiator may increase when the molecular weight is lowered. Conversely, if it exceeds 5 parts by mass, side reactions increase, Impurities may increase.

  The combination of the chain transfer agent, the initiator, and the reaction accelerator is not particularly limited, and can be appropriately selected from the above examples. For example, combinations of chain transfer agent, initiator and reaction accelerator include sodium bisulfite / sodium persulfate, hydrogen peroxide / sodium persulfate, sodium bisulfite / Fe (iron ion), sodium bisulfite / sodium persulfate. / Fe (iron ion), sodium bisulfite / oxygen / Fe (iron ion), sodium hypophosphite / sodium persulfate, and the like are preferable. More preferred are sodium bisulfite / sodium persulfate, sodium bisulfite / sodium persulfate / Fe (iron ion), and most preferred is sodium bisulfite / sodium persulfate / Fe (iron ion).

  The total amount of the chain transfer agent, initiator, and reaction accelerator used is 1 mol of all monomer components consisting of monomers (A) and (B) and, if necessary, other monomers (E). Is preferably 2 to 20 g. By setting it as such a range, the carboxyl group-containing copolymer of this invention can be produced efficiently, and the molecular weight distribution of a carboxyl group-containing copolymer can be made into a desired thing. More preferably, it is 4-18g, More preferably, it is 6-15g.

In the above polymerization step, as a method for adding monomers, polymerization initiators and the like to the reaction vessel, all of the monomers are charged into the reaction vessel, and copolymerization is performed by adding the polymerization initiator into the reaction vessel. Method: Copolymerization is carried out by charging a part of the monomer into the reaction vessel and adding the polymerization initiator and the remaining monomer continuously or stepwise (preferably continuously) into the reaction vessel. Method: A method in which a polymerization solvent is charged in a reaction vessel and the whole amount of the monomer and the polymerization initiator is added; one or more of monomers (A) and (B) are partly added to the reaction vessel. Examples thereof include a method of carrying out copolymerization by charging, adding a polymerization initiator and the remaining monomers (preferably continuously) into the reaction vessel. Among these methods, the molecular weight distribution of the resulting copolymer can be narrowed (sharp), and it tends to improve the dispersibility of silica scale when used as a scale inhibitor. It is preferable to carry out copolymerization by a method in which part or all of the polymerization initiator and part or all of the monomer are successively dropped into the reaction vessel.
The solvent may be partly or wholly charged in the reaction vessel in the initial stage of polymerization, but a part of the solvent may be added (dropped) into the reaction system during the polymerization reaction, or the monomer. Components, initiators, and the like may be added (dropped) into the reaction system during the polymerization reaction together with these components in a form in which the components and initiator are dissolved in advance.

As a polymerization method in the polymerization step, for example, it can be carried out by a commonly used method such as solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization and the like, and is not particularly limited, but solution polymerization is preferable. As described above, the solvent that can be used in this case is preferably a mixed solvent in which 50% by mass of water or water is based on the total solvent. When only water is used, it is preferable in that the solvent removal step can be omitted.
The polymerization step can be carried out either batchwise or continuously.
In the polymerization step, the polymerization temperature is usually preferably 0 ° C. or higher and preferably 150 ° C. or lower. More preferably, it is 40 degreeC or more, More preferably, it is 60 degreeC or more, Most preferably, it is 80 degreeC or more. Moreover, More preferably, it is 120 degrees C or less, More preferably, it is 110 degrees C or less. In particular, when bisulfurous acid (salt) is used, the copolymerization temperature is usually 60 ° C to 95 ° C, preferably 70 ° C to 95 ° C, and more preferably 80 ° C to 95 ° C. At this time, at 60 ° C. or lower, there is a possibility that a large amount of impurities derived from bisulfurous acid (salt) is generated. On the contrary, when it exceeds 95 ° C., toxic sulfurous acid gas may be released.
In the above polymerization step, the polymerization temperature does not always need to be kept almost constant. For example, polymerization is started from room temperature, the temperature is increased to a set temperature at an appropriate temperature increase time or rate, and then the set temperature is maintained. Depending on the dropping method of the monomer component, the initiator, etc., the temperature may be changed over time (temperature increase or decrease) during the polymerization reaction.

In the method for producing a carboxyl group-containing copolymer of the present invention, the polymerization time is preferably 30 to 300 minutes. More preferably, it is 60-240 minutes, More preferably, it is 120-180 minutes.
In the present invention, the “polymerization time” means that in the batch-type (batch-type) polymerization method, when polymerization is performed while adding a part or all of the monomer to the reactor (reaction vessel), the polymerization is performed first. From the time when a part or all of the initiator and a part or all of the monomer are added to the reactor (referred to as polymerization start time) to the time when the whole amount of monomer is added to the reactor (when polymerization is completed) To say). Further, in the batch type (batch type) polymerization method, the whole amount of the monomer is added to the reactor in advance (referred to as initial charge), and a part or all of the polymerization initiator is added to the reactor (reaction vessel). In the case of polymerization, it is from the time when all or part of the polymerization initiator and all of the monomer are first added to the reactor to the time when the entire amount of the polymerization initiator is added to the reactor. In addition, in the batch (batch type) polymerization method, when the total amount of the monomer and the total amount of the polymerization initiator are previously added to the reactor and the polymerization is performed by means such as heating, exothermic (polymerization heat) This is the time when the occurrence of Moreover, when superposing | polymerizing by a continuous type, the time which has stayed in the reactor is said.

  The pressure in the reaction system in the polymerization step may be any of normal pressure (atmospheric pressure), reduced pressure, and increased pressure, but in terms of the molecular weight of the resulting copolymer, The reaction system is preferably sealed and the reaction is carried out under pressure. Moreover, it is preferable to carry out under a normal pressure (atmospheric pressure) at the point of equipment, such as a pressurization apparatus, a pressure reduction apparatus, a pressure-resistant reaction container, and piping. The atmosphere in the reaction system may be an air atmosphere, but is preferably an inert atmosphere. For example, the inside of the system is preferably replaced with an inert gas such as nitrogen before the start of polymerization.

  The pH during the polymerization in the polymerization step is preferably acidic. In particular, when persulfate and bisulfite (salt) are used in combination as the initiator, it is preferably carried out under acidic conditions. By carrying out under acidic conditions, the increase in the viscosity of the aqueous solution of the polymerization reaction system can be suppressed, and the copolymer can be produced satisfactorily. In addition, since the polymerization reaction can proceed under high concentration conditions, the production efficiency can be greatly increased, and the final solid content concentration can be high concentration polymerization of 40% or more, and the residual contained A monomer having a total monomer concentration of 15000 ppm or less can be obtained. Furthermore, the polymerizability of the ether bond-containing monomer can be improved.

  As said acidic condition, it is preferable that pH at 25 degreeC of the reaction solution in superposition | polymerization is 1-6. More preferably, it is 5 or less, More preferably, it is 3 or less. The copolymer obtained by the above copolymerization method may be used in a neutralized state according to the pH at the end of the polymerization, but if necessary, further neutralized with an alkaline substance (both in the neutralization step). Say). As the alkaline substance, it is preferable to use inorganic salts such as hydroxides, chlorides and carbonates of monovalent metals and divalent metals; ammonia; organic ammonium (organic amine) and the like.

  In the above polymerization step, the neutralization rate of the monomer during the copolymerization can be appropriately changed depending on the initiator. For example, when persulfate and bisulfite (salt) are used in combination, it is preferable to carry out the copolymerization of the monomer components at a monomer neutralization rate of 0 to 60 mol%. The neutralization rate of the monomer is defined as a unit that forms a salt when the total number of moles of the monomer contained in the reaction solution and the carboxyl group of the structural unit derived from the monomer is 100 mol%. It is represented by the ratio (mol%) of the carboxyl group of the structural unit derived from the monomer that forms a salt with the monomer. If the neutralization rate of the monomer exceeds 60 mol%, the polymerization rate in the copolymerization step does not increase, and the molecular weight of the resulting copolymer may decrease, or the production efficiency may decrease. More preferably, it is 50 mol% or less, more preferably 40 mol% or less, particularly preferably 30 mol% or less, more particularly preferably 20 mol% or less, and most preferably 10 mol%. It is as follows.

  The production method of the present invention usually includes a polymerization step as an essential step. In addition, the neutralization process, the refinement | purification process, etc. may be included.

  The carboxyl group-containing copolymer (or polymer composition) is suitably used as a water treatment agent such as a scale inhibitor, as well as a fiber treatment agent, a dispersing agent, a deinking agent, a metal ion sealing agent, a reinforcing agent. It can be used as a sticking agent, various binders, emulsifiers, skin care agents, hair care agents and the like.

<Water treatment agent>
The carboxyl group-containing copolymer (or polymer composition) of the present invention can be used as a water treatment agent such as a scale inhibitor alone or together with other compounding agents. If necessary, the water treatment agent may contain a polymerized phosphate, phosphonate, anticorrosive, slime control agent, and chelating agent as other compounding agents. The content of the carboxyl group-containing copolymer of the present invention in the water treatment agent is preferably 1 to 100% by weight, more preferably 5 to 100% by weight, based on the entire water treatment agent.

  The water treatment agent is useful for scale prevention in a cooling water circulation system, a boiler water circulation system, a seawater desalination apparatus, a pulp digester, a black liquor concentration tank, and the like. Further, any appropriate water-soluble polymer may be included as long as it does not affect the performance and effects.

<Deinking agent>
The carboxyl group-containing copolymer (or polymer composition) of the present invention can be used as a deinking agent. The deinking agent according to the present invention includes various commonly used agents as required, specifically, for example, alkaline agents such as sodium hydroxide, sodium silicate, sodium carbonate; hydrogen peroxide, Bleaching agents such as sodium hypochlorite and hydrosulfite; chelating agents such as ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA); hydrogen peroxide stabilizers, foaming agents, pitch control agents, dissociation accelerators, or Although it can be used in combination with a known deinking agent, it is not particularly limited. Examples of known deinking agents that can be used in combination with the deinking agent according to the present invention include, for example, higher fatty acid soaps, anionic surfactants, and various nonionic surfactants. However, it is not particularly limited. In addition, in the known deinking process using both a nonionic surfactant and a cationic compound, the deinking agent according to the present invention is used in combination as long as there is no particular problem in performing the deinking process. can do.

  The content of the carboxyl group-containing copolymer of the present invention in the deinking agent according to the present invention is not particularly limited, but is more preferably in the range of 1% by weight to 100% by weight, and 2% by weight to 100%. More preferably within the range of wt%, particularly preferably within the range of 10 wt% to 100 wt%, and most preferably within the range of 20 wt% to 100 wt%. In addition, the amount of the above-mentioned various drugs that can be used in combination with the deinking agent according to the present invention and known deinking agents may be within a range that does not hinder the effects of the deinking agent according to the present invention, It is not particularly limited.

  The deinking treatment method using the deinking agent according to the present invention is not particularly limited, and a known general method, for example, a cleaning method or a flotation method, or a compromise between the cleaning method and the flotation method. Laws can be adopted. More specifically, for example, in the deinking process, the pulp slurry is generally crushed in water to obtain a pulp slurry by pulverizing waste paper (printed waste paper), and the pulp slurry is allowed to stand for a predetermined time after the pulverization process. It comprises at least an aging step for aging, a removing step for removing ink by removing it from the pulp (fiber), and a washing step for filtering and washing the pulp slurry from which the ink has been removed. Each of these steps is repeated two or more times if necessary, depending on the printing technique, the composition and amount of ink (oil-based ink), the properties of used paper, and the like. In addition to the above steps, a dehydration step, a screen step, a dispersion step, etc., which are usually performed in the deinking process, can also be performed.

  Specific examples of the pulp forming the used paper include high yield pulp such as mechanical pulp (MP) and chemical mechanical pulp (CGP); deinked pulp (DIP); soda pulp (AP ) And kraft pulp (KP), etc .; wood pulp such as, but not limited to.

  Examples of the crusher (disintegrator) used in the crushing step include a pulper, a refiner, and a kneader. Although the pulp density | concentration in a pulp slurry is not specifically limited, The inside of the range of 3 weight%-25 weight% is suitable. The temperature of the pulp slurry is preferably in the range of 20 ° C to 70 ° C. The pH of the pulp slurry is preferably in the range of 7.5 to 11.5, and optimally in the range of 8.0 to 11.5.

  The pulp concentration in the aging step is not particularly limited, but is preferably in the range of 10% by weight to 30% by weight. The temperature of the pulp slurry is preferably in the range of 30 ° C to 80 ° C. The aging time of the pulp slurry is not particularly limited, but 1 hour or more is preferable.

  Although the pulp density | concentration in a removal process is not specifically limited, The inside of the range of 0.5 weight%-1.5 weight% is suitable. The temperature of the pulp slurry is preferably in the range of 20 ° C to 50 ° C. As the removal process, a flotation process is preferable. The method for forming bubbles in the flotation process is not particularly limited.

  The calcium ion concentration of water used in the deinking treatment is not particularly limited, and is generally within a range of 10 ppm to 400 ppm, more preferably within a range of 100 ppm to 250 ppm, which is a concentration exhibited by industrial water or tap water. If it is enough. If the calcium ion concentration of water is within the above range, fine pulp is adsorbed by a larger pulp, and thus regenerated pulp can be obtained with good yield. Further, reattachment of the ink to the pulp can be suppressed. The aluminum ion concentration of the water is not particularly limited, and 40 ppm or less, more preferably 25 ppm or less is sufficient. Since the deinking agent according to the present invention has a polyanion structure in which a large number of carboxyl groups are introduced, the calcium ion concentration and the aluminum ion concentration in the pulp slurry can be maintained at appropriate values. The process can be performed more easily.

  The pH of the water used in the deinking process is not particularly limited. The pH of the water can be adjusted using a general acid / base. Since the deinking agent according to the present invention has good dispersibility in pulp slurry, it is excellent in operability.

  The amount of the deinking agent used may be set according to the printing technique, the ink composition and amount, the properties of the wastepaper, etc., and is not particularly limited, but the dry weight of the wastepaper to be deinked (absolutely dry) The weight is more preferably in the range of 0.05% to 10% by weight, and still more preferably in the range of 0.1% to 5% by weight. If the amount used is less than 0.05% by weight, the ink may not be sufficiently removed. On the other hand, even if the amount used is more than 10% by weight, no further effect can be expected, and excess deinking agent is wasted.

<Fiber treatment agent>
The carboxyl group-containing copolymer (or polymer composition) of the present invention can be used as a fiber treatment agent. The fiber treatment agent includes at least one selected from the group consisting of a dye, a peroxide and a surfactant, and the carboxyl group-containing copolymer of the present invention.
The content of the carboxyl group-containing copolymer of the present invention in the fiber treatment agent is preferably 1 to 100% by weight, more preferably 5 to 100% by weight, based on the entire fiber treatment agent. Further, any appropriate water-soluble polymer may be included as long as the performance and effects are not affected.

  Below, the compounding example of the fiber processing agent which is closer to embodiment is shown. This fiber treatment agent can be used in the steps of refining, dyeing, bleaching and soaping in fiber treatment. Examples of dyeing agents, peroxides and surfactants include those usually used for fiber treatment agents.

  The blending ratio of the carboxyl group-containing copolymer of the present invention to at least one selected from the group consisting of a dye, a peroxide, and a surfactant is, for example, the whiteness of the fiber, uneven color, and dyeing tempering degree. For the improvement, at least one selected from the group consisting of a dyeing agent, a peroxide and a surfactant with respect to 1 part by weight of the carboxyl group-containing copolymer of the present invention in terms of pure amount of the fiber treatment agent. It is preferable to use the composition mix | blended in the ratio of 0.1-100 weight part as a fiber processing agent.

  Arbitrary appropriate fiber can be employ | adopted as a fiber which can use the said fiber processing agent. Examples thereof include cellulosic fibers such as cotton and hemp, chemical fibers such as nylon and polyester, animal fibers such as wool and silk, semi-synthetic fibers such as human silk, and woven fabrics and blended products thereof.

When the fiber treatment agent is applied to the refining process, it is preferable to blend the carboxyl group-containing copolymer of the present invention with an alkali agent and a surfactant. When applied to the bleaching step, it is preferable to blend the carboxyl group-containing copolymer of the present invention, a peroxide, and a silicic acid-based agent such as sodium silicate as a decomposition inhibitor for the alkaline bleaching agent.
<Inorganic pigment dispersant>
The carboxyl group-containing copolymer (or polymer composition) of the present invention can be used as an inorganic pigment dispersant. If necessary, the inorganic pigment dispersant may contain condensed phosphoric acid and its salt, phosphonic acid and its salt, and polyvinyl alcohol as other compounding agents.

  The content of the carboxyl group-containing copolymer of the present invention in the inorganic pigment dispersant is preferably 5 to 100% by weight with respect to the whole inorganic pigment dispersant. Further, any appropriate water-soluble polymer may be included as long as it does not affect the performance and effect.

  The inorganic pigment dispersant can exhibit good performance as a dispersant for heavy or light calcium carbonate or clay inorganic pigment used in paper coating. For example, by adding a small amount of an inorganic pigment dispersant to an inorganic pigment and dispersing it in water, high concentration calcium carbonate having low viscosity and high fluidity and good aging stability of their performance. High concentration inorganic pigment slurries such as slurries can be produced.

  When the inorganic pigment dispersant is used as a dispersant for an inorganic pigment, the amount of the inorganic pigment dispersant used is preferably 0.05 to 2.0 parts by weight with respect to 100 parts by weight of the inorganic pigment. When the amount of the inorganic pigment dispersant used is within the above range, a sufficient dispersion effect can be obtained, and an effect commensurate with the addition amount can be obtained, which can be economically advantageous.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by mass” and “%” means “% by mass”.
Moreover, the weight average molecular weight of the carboxyl group-containing copolymer of this invention, the dispersibility of a silica scale, etc. were measured in accordance with the following method.

<Measurement conditions of weight average molecular weight>
Device: Hitachi L-7000 Series Detector: RI
Column: SHODEX Asahipak GF-310-HQ, GF-710-HQ, GF-1G 7B manufactured by Showa Denko KK
Column temperature: 40 ° C
Flow rate: 0.5 ml / min.
Calibration curve: POLYACRYLIC ACID STANDARD made by Soka Science Co., Ltd.
Eluent: 0.1N sodium acetate / acetonitrile = 3/1 (mass ratio)
<Silica scale dispersibility>
Pure water was added to 67.56 g of glycine, 52.6 g of sodium chloride, and 2.4 g of NaOH to make 600 g (this is referred to as buffer (1)). To 60 g of buffer (1), 0.3268 g of calcium chloride dihydrate was added, and pure water was further added to make 1000 g (this is referred to as buffer (2)). 36 g of buffer (2) was added to 4 g of a 0.1% by weight aqueous solution of the copolymer to be measured, and stirred to obtain a dispersion. After 0.9 g of talc (manufactured by Wako Pure Chemical Industries, Ltd.) as silica scale is put in a test tube (made by IWAKI GLASS, diameter 18 mm, height 180 mm), 30 g of the above dispersion is added and sealed.
The test tube was shaken to uniformly disperse talc. Thereafter, the test tube was left in the dark for 3 hours. After 1 hour, 5 cc of the supernatant of the dispersion was taken and the absorbance was measured with a UV spectrometer (Shimadzu Corporation, UV-1200; inner dimensions are a cell with a bottom area of 1 cm ² × height of 4.5 cm, wavelength 380 nm). It shows that a silica scale dispersibility is so high that this value is large.

<Method for measuring solid content of polymer composition>
In a nitrogen atmosphere, the polymer composition (polymer composition 1.0 g + water 3.0 g) was left to dry for 1 hour in an oven heated to 130 ° C. From the weight change before and after drying, the solid content (%) and the volatile component (%) were calculated.

<Synthesis Example 1>
A 200 mL glass four-necked flask equipped with a stirrer (paddle blade) and a reflux condenser was charged with 43.0 g of isoprenol and 0.93 g of potassium hydroxide (hereinafter also referred to as “KOH”), and nitrogen was introduced. While stirring, the temperature was raised to 60 ° C., and this state was maintained for 30 minutes to dissolve KOH. Next, 50.0 g of hexene oxide (hereinafter also referred to as “HxO”) was added over 30 minutes, and then the reaction was allowed to proceed at 60 ° C. for 72 hours. After cooling to room temperature, this solution is transferred to a 500 ml separatory funnel, 100.0 g of a 20% aqueous sodium chloride solution (hereinafter also referred to as “20% NaCl”) is added, and the mixture is stirred well and allowed to stand until the layers are separated. The lower layer was removed. This operation was repeated three times, and the remaining upper layer was transferred to a 300 ml eggplant flask and desolvated with a rotary evaporator. The precipitated salt was removed by filtration to obtain monomer (1).

<Synthesis Example 2>
A 200 mL glass four-necked flask equipped with a stirrer (paddle blade) and a reflux condenser was charged with 29.0 g of allyl alcohol and 0.79 g of KOH, heated to 60 ° C. while introducing nitrogen and stirring, By maintaining this state for 30 minutes, KOH was dissolved. Next, 50.0 g of HxO was added over 30 minutes, and then the reaction was allowed to proceed at 60 ° C. for 5 hours. After cooling to room temperature, this solution was transferred to a 500 ml separatory funnel, 100.0 g of 20% NaCl was added, stirred well, allowed to stand until the layers were separated, and the lower layer was removed. This operation was repeated three times, and the remaining upper layer was transferred to a 300 ml eggplant flask and desolvated with a rotary evaporator. The precipitated salt was removed by filtration to obtain monomer (2).

<Synthesis Example 3>
In Synthesis Example 1, a SUS autoclave was used instead of a 200 mL glass four-necked flask equipped with a reflux condenser, and 87.0 g of propylene oxide was used instead of 50.0 g of hexene oxide. A propylene oxide 3-mol adduct (monomer (3)) to isoprenol was obtained in the same manner as in Synthesis Example 1, except that 0.65 g of KOH was used instead of 0.93 g of KOH.

<Synthesis Example 4>
In Synthesis Example 2, an SUS autoclave was used instead of a 200 mL glass four-necked flask equipped with a reflux condenser, and 87.0 g of propylene oxide was used instead of 50.0 g of hexene oxide. A propylene oxide 3 mol adduct (monomer (4)) to allyl alcohol was obtained in the same manner as in Synthesis Example 2, except that 0.58 g of KOH was used instead of 0.79 g of KOH.

<Synthesis Example 5>
In Synthesis Example 1, a SUS autoclave was used instead of a 200 mL glass four-necked flask equipped with a reflux condenser, but 52.0 g of hexene oxide was used, and 72.0 g of butylene oxide was used. A butylene oxide 2-mole adduct (monomer (5)) to isoprenol was obtained in the same manner as in Synthesis Example 1, except that 0.58 g of KOH was used instead of 0.93 g of KOH.

<Synthesis Example 6>
In Synthesis Example 2, a SUS autoclave was used instead of a 200 mL glass four-necked flask equipped with a reflux condenser, and 52.0 g of hexene oxide was used, and 72.0 g of butylene oxide was used. A butylene oxide 2-mole adduct (monomer (6)) to allyl alcohol was obtained in the same manner as in Synthesis Example 2 except that 0.51 g of KOH was used instead of 0.79 g of KOH.

<Example 1>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 99.7 g of pure water and 0.0110 g of Mole salt, and the temperature was raised to 85 ° C. while stirring to polymerize the reaction. It was a system. Next, 180.0 g of an 80% aqueous acrylic acid solution (hereinafter also referred to as “80% AA”), monomer (1) 25.4 g, 15 in a polymerization reaction system maintained at 85 ° C. with stirring. 42.7 g of an aqueous sodium persulfate solution (hereinafter also referred to as “15% NaPS”) and 30.5 g of an aqueous 35% sodium bisulfite solution (hereinafter also referred to as “35% SBS”) More dripped. The dropping time of each solution was 180 minutes for 80% AA, 90 minutes for monomer (1), 190 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 85 ° C. (ripening) for another 30 minutes to complete the polymerization. After completion of the polymerization, while stirring and allowing the polymerization reaction liquid to cool, 141.7 g of a 48% aqueous sodium hydroxide solution (hereinafter also referred to as “48% NaOH”) was gradually added dropwise to neutralize the polymerization reaction liquid.
In this manner, a polymer aqueous solution (polymer aqueous solution (1)) having a solid content concentration of 45% was obtained. The total amount of residual monomers contained in the polymer aqueous solution (1) was less than 1000 ppm, and the weight average molecular weight of the polymer (polymer (1)) contained in the polymer aqueous solution (1) was 12,500. .

<Example 2>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 113.1 g of pure water and 0.0129 g of Mole salt, and the temperature was raised to 85 ° C. while stirring to polymerize the reaction. It was a system. Next, 80% AA 225.0 g, monomer (1) 20.0 g, 15% NaPS 52.2 g, and 35% SBS 22.4 g were respectively added to the polymerization reaction system maintained at 85 ° C. with stirring. Dropped from separate nozzles. The dropping time of each solution was 180 minutes for 80% AA, 120 minutes for monomer (1), 190 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 85 ° C. (ripening) for another 30 minutes to complete the polymerization. After completion of the polymerization, 177.1 g of 48% NaOH was gradually added dropwise while stirring and allowing the polymerization reaction liquid to cool, thereby neutralizing the polymerization reaction liquid.
In this way, a polymer aqueous solution (polymer aqueous solution (2)) having a solid content concentration of 45% was obtained. The total amount of residual monomers contained in the polymer aqueous solution (2) was less than 1000 ppm, and the weight average molecular weight of the polymer (polymer (2)) contained in the polymer aqueous solution (2) was 20,700. .

<Example 3>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 120.5 g of pure water and 0.0148 g of Mole salt, and the temperature was raised to 85 ° C. while stirring to polymerize the reaction. It was a system. Next, in the polymerization reaction system maintained at 85 ° C. with stirring, 270.0 g of 80% AA, 11.4 g of monomer (2), 61.4 g of 15% NaPS, and 26.3 g of 35% SBS were respectively obtained. Dropped from separate nozzles. The dropping time of each solution was 180 minutes for 80% AA, 120 minutes for monomer (2), 190 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 85 ° C. (ripening) for another 30 minutes to complete the polymerization. After completion of the polymerization, 212.5 g of 48% NaOH was gradually added dropwise while stirring and allowing the polymerization reaction liquid to cool, thereby neutralizing the polymerization reaction liquid.
In this way, a polymer aqueous solution (polymer aqueous solution (3)) having a solid content concentration of 45% was obtained. The total of residual monomers contained in the polymer aqueous solution (3) was less than 1000 ppm, and the weight average molecular weight of the polymer (polymer (3)) contained in the polymer aqueous solution (3) was 18,700. .

<Comparative Example 1>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 106.4 g of pure water and 0.0142 g of Mole salt, and the temperature was raised to 85 ° C. while stirring to polymerize the reaction. It was a system. Next, 270.0 g of 80% AA, 60.0 g of 15% NaPS, and 25.7 g of 35% SBS were dropped from separate nozzles into the polymerization reaction system maintained at 85 ° C. with stirring. The dropping time of each solution was 180 minutes for 80% AA, 190 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 90 ° C. (ripening) for 30 minutes to complete the polymerization. After completion of the polymerization, 212.5 g of 48% NaOH was gradually added dropwise while stirring and allowing the polymerization reaction liquid to cool, thereby neutralizing the polymerization reaction liquid.
In this manner, a comparative polymer aqueous solution (comparative polymer aqueous solution (1)) having a solid content concentration of 45% was obtained. The weight average molecular weight of the comparative polymer (comparative polymer (1)) contained in the comparative polymer aqueous solution (1) was 14,600.

<Example 4>
About the polymer obtained in Examples 1-3, the dispersibility of a silica scale was evaluated according to the said method. As a comparative example, silica scale of the polymer obtained in Comparative Example 1 and sodium polyacrylate having a weight average molecular weight of 5,500 (referred to as “Aquaric YS100” manufactured by Nippon Shokubai Co., Ltd., comparative polymer (1)). The dispersibility of was evaluated. The results are summarized in Table 1.

  As is apparent from Table 1, it was revealed that the polymer of the present invention has an excellent silica scale dispersibility as compared with conventional polymers. Therefore, the polymer of the present invention can be suitably used as a water treatment agent.

Claims (4)

1% by mass or more and 49% by mass or less of the structural unit (a) derived from the ether bond-containing monomer (A) represented by the following general formula (1),
A carboxyl group-containing copolymer having, as an essential constituent unit, a structural unit (b) derived from 51% by mass to 99% by mass of the carboxyl group-containing monomer (B).

In the formula, R ₀ represents a hydrogen atom or a CH ₃ group,
R ₁ represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond,
R ₂ is the same or different and represents an alkylene group having 4 to 6 carbon atoms;
n is an average addition mole number of the oxyalkylene group (—R ₂ —O—), and represents a number of 1 to 5;
R ₃ represents a hydrogen atom or an organic group having 1 to 7 carbon atoms. R in the general formula (1) ₀ But CH ₃ R and R ₁ But CH ₂ CH ₂ Base
The carboxyl group-containing copolymer according to claim 1. The weight average molecular weight is 2,000 to 200,000
The carboxyl group-containing copolymer according to claim 1 or 2. 1% by mass or more and 49% by mass or less of an ether bond-containing monomer (A) represented by the following general formula (1),
The manufacturing method of a carboxyl group-containing copolymer including the process of superposing | polymerizing 51 mass% or more and 99 mass% or less of carboxyl group-containing monomers (B) as an essential component.

In the formula, R ₀ represents a hydrogen atom or a CH ₃ group,
R ₁ represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond,
R ₂ is the same or different and represents an alkylene group having 4 to 6 carbon atoms;
n is an average addition mole number of the oxyalkylene group (—R ₂ —O—), and represents a number of 1 to 5;
R ₃ represents a hydrogen atom or an organic group having 1 to 7 carbon atoms.