JP2003277427A - Method for producing water-soluble polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a water-soluble polymer having a low degree of polymerization with which the amount required of a chain transfer agent is suppressed to a low concentration and the efficiency of the initiator is raised to reduce the amount required thereof for increasing the purity of the produced polymer or its solution and suppressing the production of molecules of bound initiator fragments to a low extent. <P>SOLUTION: The method for producing the water-soluble polymer is carried out as follows. One or more monomers selected from specific water-soluble monomers or monomers consisting essentially of a water-soluble monomer mixture are polymerized in an aqueous solution within the range of ≥70°C to the vicinity of the boiling point of the aqueous solution under atmospheric pressure with a redox initiator. Furthermore, in the redox initiator, the equivalent ratio in the oxidation-reduction reaction is set at 10-50 number of equivalents of the reducing agent/number of equivalent of the oxidizing agent. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a water-soluble polymer, and more particularly to a monomer or a mixture of monomers selected from one or more specific water-soluble monomers. To polymerize the monomer to be used under atmospheric pressure in the vicinity of the boiling point of the aqueous solution with a redox initiator in which the equivalent ratio in the redox reaction is set to the equivalent number of reducing agent / equivalent number of oxidizing agent = 5 to 50. And a method for producing a water-soluble polymer.

[0002]

2. Description of the Related Art Among water-soluble polymer substances, particularly low-polymerization polymers are used as builders such as surface coating agents for various printing papers, cement additives, pigment dispersants, hydraulic fluids, metal scavengers or detergents. It has been applied and is expected to develop in the future. Conventionally, low-polymerization degree polymers have been synthesized by polymerization or polycondensation reaction of vinyl compounds. Among them, the water-soluble polycondensation polymer has a low degree of polymerization, but from the viewpoint of ionicity, a cationic one is likely to be generated, and the degree of freedom such as polymerization degree and ionicity is high. Is difficult to select. Therefore, in consideration of application, vinyl compound polymers are most convenient.

By the way, as a method of addition polymerization of a vinyl compound, a method of coexisting a large amount of a chain transfer agent or a polymerization initiator, polymerization at a high temperature, or the like is adopted. However, in order to obtain a polymer having a low degree of polymerization, a chain transfer agent or a polymerization initiator has been added more than necessary. As a result, the unreacted chain transfer agent and the initiator are present in the produced polymer and its solution, and the purity is lowered. Alternatively, it is expected that a large amount of molecules in which the chain transfer agent or the initiator fragment is bound to the end of the polymer will be produced, and the physical properties of the polymer will be delicately affected.

[0004]

The object of the present invention is to increase the purity of the produced polymer or its solution and to suppress the production of the molecule to which the initiator fragment is bound. Therefore, it is an object to develop a method for producing a low polymerization degree polymer solution in which the required amount of the chain transfer agent is suppressed to a low concentration and the efficiency of the initiator is increased to reduce the required amount.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventor has earnestly studied and, as a result, arrived at the following invention. That is, the invention of claim 1 of the present invention is mainly composed of a monomer or monomer mixture selected from one or more water-soluble monomers represented by the following general formulas (1) to (4). Starting the redox system in which the equivalence ratio in the oxidation-reduction reaction is set to 10 to 50 equivalents of reducing agent at a temperature of 70 ° C. or higher under atmospheric pressure and near the boiling point of the aqueous solution. A method for producing a water-soluble polymer, which comprises polymerizing with an agent.

[Chemical 1] General formula (1) R1 is hydrogen, a methyl group or a carboxymethyl group, A is SO3, C6H4SO3, CONHC (CH3) 2CH
2SO3, C6H4COO or COO, R2 is hydrogen or COOY2, Y1 or Y2 is hydrogen or cation

[Chemical 2] Formula (2) R3 is hydrogen or a methyl group, R4 and R5 are alkyl or alkoxyl groups having 1 to 3 carbon atoms, R6 is hydrogen, an alkyl group having 1 to 3 carbon atoms, an alkoxyl group, or a benzyl group. May be different, A is oxygen or N
H and B represent an alkylene group having 2 to 4 carbon atoms or an alkoxylene group, and X1 represents an anion.

[Chemical 3] General formula (3) R7 is hydrogen or a methyl group, R8 and R9 are C1-C3 alkyl, an alkoxyl group, or a benzyl group,
X2 represents an anion, respectively.

[Chemical 4] R10, Q is NHCOR11, R11 is hydrogen or a lower alkyl group, COABR12, A is NH or O, R1
2 represents hydrogen or a lower alkyl group. General formula (4)

A second aspect of the present invention is the method for producing a water-soluble polymer according to the first aspect, wherein a chain transfer agent is allowed to coexist in the aqueous solution.

According to the third aspect of the present invention, while maintaining the total concentration of the monomer in the reaction solution at 2 to 10% by weight, the required amount of the monomer is added to the reaction solution in several divided portions. The method for producing a water-soluble polymer according to claim 1, wherein

According to the invention of claim 4, while maintaining the total concentration of the monomer in the reaction solution at 2 to 10% by weight, the required amount of the monomer is continuously added to the reaction solution. The method for producing a water-soluble polymer according to claim 1, which is characterized in that.

The invention of claim 5 is the method for producing a water-soluble polymer according to claim 1, wherein the water-soluble polymer is nonionic.

The invention of claim 6 is characterized in that the water-soluble polymer is cationic or amphoteric.
The method for producing a water-soluble polymer described in 1.

The invention of claim 7 is the method of producing a water-soluble polymer according to claim 1, wherein the water-soluble polymer is anionic.

The invention of claim 8 is the method for producing a water-soluble polymer according to claim 1, wherein the water-soluble polymer has a weight average molecular weight of 1,000 to 200,000.

The invention of claim 9 relates to the general formula (1) to
The total amount of the redox type initiator based on the monomer mixture mainly composed of one or more monomers selected from the water-soluble monomers represented by (4) is 0.05 to 1 mass. % Is the method for producing a water-soluble polymer according to claim 1.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing a water-soluble polymer of the present invention comprises a monomer or monomer selected from one or more of the water-soluble monomers represented by the above general formulas (1) to (4). At a temperature of 70 ° C. or more and a temperature near the boiling point of the aqueous solution at atmospheric pressure, a monomer mainly composed of a monomer mixture is used, and the equivalence ratio in the oxidation-reduction reaction is represented by the equivalent number of reducing agent / equivalent number of oxidizing agent = 10. ~ 5
This is a method for producing a water-soluble polymer by polymerizing with a redox-based initiator set to 0. Conventionally, in order to synthesize a polymer having a low degree of polymerization, a large amount of azo-based or peroxide-based initiator was simply added and polymerized. Further, even with the redox type initiator, the molecular weight was lowered by adding a large amount without considering the reducing agent / oxidizing agent equivalent ratio.

Of the redox initiators, however, the reducing agent is often a substance such as sulfite and amines, which easily causes a chain transfer reaction. Therefore, focusing on the reducing agent / oxidizing agent equivalent ratio, if the reducing agent equivalent ratio is increased, a chain transfer reaction is likely to occur, and the oxidation and reduction reactions are promoted. Polymers are easily generated. The present inventor paid attention to this point and studied. Further, by carrying out the temperature at 70 ° C. or higher to a temperature near the boiling point of the monomer solution, the decomposition of the redox type initiator and the chain transfer reaction were promoted. Further, by setting the monomer solution concentration to a low value such as 2 to 10% by mass, the growth reaction rate is reduced and the polymerization degree is lowered.

As described above, the present invention has developed a method of synthesizing a low-polymerization degree polymer near the boiling point of a monomer solution by setting the equivalent ratio of reducing agent / oxidizing agent to 10 to 50. Among the redox-based initiators used in the present invention, as the oxidizing agent,
Examples thereof include ammonium peroxodisulfate, potassium peroxodisulfate, hydrogen peroxide and the like. Examples of the reducing agent include sodium sulfite, sodium hydrogen sulfite, sodium thiosulfate, trimethylamine, tetramethylethylenediamine and triethanolamine, and those having a large chain transfer reaction are particularly preferable. A preferable combination is ammonium peroxodisulfate or potassium peroxodisulfate and sodium bisulfite.

The polymerization concentration is a concentration of a monomer mainly composed of a monomer or a monomer mixture selected from one or more water-soluble monomers represented by the above general formulas (1) to (4). Is 10
It is preferable that the content is low such as not more than the mass, but particularly when synthesizing a polymer having a low degree of polymerization, it is effective to set the content to 5 to 2 mass%. When it is 10% by mass or more, the probability of collision of molecules with each other increases, and a low-polymerization degree polymer is hard to be generated. Also, 2
If it is less than mass%, it is not efficient in consideration of economy.

The polymerization temperature is a temperature of 70 ° C. or higher and around the boiling point of the monomer solution. That is, the higher the temperature is, the more effective the chain transfer is because the higher the temperature is, the more efficient the chain transfer is. However, it is necessary to use a special device such as a device under high pressure, which increases the manufacturing cost. Therefore, the temperature that can be achieved under the atmospheric pressure is 70 ° C. or higher and is in the range up to the boiling point of the monomer solution. Specifically, the temperature is 70 to 110 ° C., preferably 80 to 105 ° C., although it is often higher than pure water because the boiling point rises due to the dissolved substance.

In the polymerization method of the present invention, since the polymerization is carried out at a low concentration, the concentration of the polymer in the solution concentration produced is low, which is not practical. Therefore, the polymerization reaction itself has a monomer concentration of 10
It is carried out at a mass% or less, but after the supplied monomers are polymerized,
If a monomer is further added and polymerization is repeated, a product having a high concentration can be finally produced. There are two methods for supplying the additional monomer. One is a method in which the required amount of the monomer is divided and fed several times, and a method in which the required amount of the monomer is continuously fed into the polymerization apparatus. In either case, the concentration of the monomer during polymerization is 10
The reaction is carried out while keeping the content at less than the weight%.

The monomer used in the present invention is a water-soluble monomer, a water-soluble monomer mixture, or a mixture of one or more water-soluble monomers or a mixture of water-soluble monomers. As a raw material. As an example of such a monomer, an acrylic type or a diallylamine type is used as a cationic type.
Specifically, it is a salt of an inorganic or organic acid such as dimethylaminoethyl (meth) acrylate or dimethylaminopropyl (meth) acrylamide, or a quaternary ammonium salt of methyl chloride or benzyl chloride. That is, (meth) acryloyloxyethyltrimethylammonium chloride, (meth) acryloyloxy 2-hydroxypropyltrimethylammonium chloride, (meth) acryloylaminopropyltrimethylammonium chloride,
Examples thereof include (meth) acryloyloxyethyldimethylbenzylammonium chloride, (meth) acryloyloxy 2-hydroxypropyldimethylbenzylammonium chloride and (meth) acryloylaminopropyldimethylbenzylammonium chloride. In the diallylamine type, salts of organic / inorganic acid of methyldiallylamine, dimethyldiallylammonium chloride polymer, methylbenzylallylammonium chloride polymer and the like are included.

Examples of the anionic monomer include (meth)
Acrylic acid, maleic acid, itaconic acid, acrylamido 2-methylpropanesulfonic acid (salt), styrenesulfonic acid (salt), vinyl sulfonic acid and the like. Examples of the nonionic monomer include acrylamide, N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone, N, N-dimethylacrylamide, diacetone acrylamide, and 2-hydroxyethyl (meth) acrylate. And so on.

Further, to the extent that the resulting polymer remains water-soluble,
It is also possible to copolymerize a water-soluble monomer with a slightly soluble or insoluble monomer in water. Examples of such a monomer include acrylonitrile, styrene, methyl acrylate, methyl methacrylate or octyl acrylate. In addition, a suitable chain transfer agent may be appropriately added, or a monomer having a plurality of vinyl groups may be copolymerized.

The water-soluble polymer of the present invention can be produced as nonionic, cationic, anionic or amphoteric depending on the composition of the monomers to be combined. The most easily produced molecular weight is 1000 to 200,000. The water-soluble polymer in this range is applicable to various uses using a low-polymerization degree polymer, and is most industrially useful. The degree of polymerization can be adjusted by the monomer concentration during the polymerization, the amount of the polymerization initiator added, the polymerization temperature, and the kind or the amount of the chain transfer agent to coexist.

Since the polymerization is carried out in an aqueous solution, when synthesizing a cationic polymer or an amphoteric polymer, the pH of the aqueous solution is usually adjusted to 2-6. That is, when a primary or tertiary amino group-containing monomer is polymerized or copolymerized, it is neutralized with an acid and then adjusted to the above pH. In the case of a quaternary ammonium salt group-containing monomer, it is usually kept on the weakly acidic side, and therefore the above pH is adjusted with an acid. In the case of an anionic monomer, it is neutralized with an alkaline substance and then adjusted from alkali to weakly acidic side for polymerization.

The low-molecular-weight water-soluble polymer synthesized in the present invention is used as a pretreatment agent for a papermaking raw material containing a large amount of waste paper or mechanical pulp, as a surface treatment agent for ink jet printing paper, as a dispersant for dispersion polymerization, Application to sludge dewatering and wastewater treatment as an alternative to inorganic coagulants, stabilizers for emulsion products, other builders for detergents, various reactive coatings used during or after polymerization with reactive groups, and various coating agents It can be expected to be applied to.

[0026]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

[0027]

Example 1 500 mL of 4 equipped with a thermometer, a stirrer, a nitrogen introducing tube, a monomer supply tube connected to a peristaltic pump (SMP-21 type, manufactured by Tokyo Rikakikai), and a condenser.
Ion-exchanged water 130.0 g, acryloyloxyethyl trimethyl ammonium chloride 80 in a two-necked flask.
% Aqueous solution of 1% and 2.0 g of 50% aqueous solution of acrylamide were charged to adjust the pH of the aqueous solution to 4.5. The molar ratio of the monomers is 80:20 in the order of the monomers,
The monomer concentration is 8%. Cover the reactor with a heater, heat the solution until it boils and keep it at that temperature.
After replacing the atmosphere with nitrogen for 30 minutes, 1.2 g of an aqueous solution of ammonium peroxodisulfate of 1.2% (0.01% of monomer) and 0.9 g of an aqueous solution of 2.0% sodium bisulfite (0% of monomer) were used as initiators. 0.1%, redox equivalent ratio 1: 1
0) was added to each to initiate polymerization. Polymerization start 1
After a lapse of time, the rate of polymerization was measured by liquid chromatography and found to be 99.1%. Then, a monomer solution having the same molar ratio was added to 28.6 g of a 50% aqueous solution so that the monomer concentration was 8%, 1.2 g of the redox initiator solution ammonium peroxodisulfate and 0.9 g of an aqueous sodium hydrogen sulfite solution. Was added to the solution. Similarly, the temperature in the reactor was kept near the boiling point and the polymerization was continued in a nitrogen stream. One hour after the addition of the monomer solution, the reaction rate was measured by the same operation, and it was 98.5%. After this, 50% aqueous solution 3
A solution was prepared in which 9.3 g and the initiator solution were added at the same ratio. At this time, the monomer concentration is 9.0%. After charging the monomer for the third time, the temperature was lowered to 60 ° C., and the reaction was further continued for 3 hours to complete the reaction. When the final reaction rate is measured, it is 9
It was 9.0%. Further, the weight average molecular weight (DLS-7000 manufactured by Otsuka Electronics Co., Ltd.) was measured by the static light scattering method and found to be 7,000. The results are shown in Table 1.

[0028]

[Example 2] 500 mL of 4 equipped with a thermometer, a stirrer, a nitrogen introducing pipe, a monomer supply pipe connected to a peristaltic pump (SMP-21 type, manufactured by Tokyo Rika Kikai) and a condenser
123.0 g of ion-exchanged water, 5.0 g of a 60% aqueous solution of acrylic acid and 12.6 g of a 50% aqueous solution of acrylamide were charged into a two-necked flask and neutralized with 4.0 g of a 30% aqueous solution of sodium hydroxide to adjust the pH to 6. Adjusted to 8. Monomer molar ratio is acrylic acid 30 mol%, acrylamide 70
%, And the monomer concentration is 6%. Cover the reactor with a heater and raise it to 90 ° C and maintain it at that temperature.
After purging with nitrogen for min., 1.4 g of a 0.2% ammonium peroxodisulfate aqueous solution was used as an initiator (compared to monomer
015%), sodium bisulfite 2.0% aqueous solution 0.1.
8 g (0.225% of monomer, 1: 1 in redox equivalent ratio)
5) was added to each to initiate polymerization. Polymerization start 1
After a lapse of time, the rate of polymerization was measured by liquid chromatography and found to be 98.0%. Thereafter, a monomer solution having the same molar ratio and a solution prepared by adding the same amount of the redox initiator solution to 20.5 g of a 50% aqueous solution so as to have a monomer concentration of 6% were charged in the reactor. . Similarly, the temperature in the reactor was kept at 90 ° C. and the polymerization was continued in a nitrogen stream. 1 hour after the addition of the monomer solution, the reaction rate was measured by the same operation.
It was 97.8%. Then, a solution in which 37.6 g of a 50% monomer concentration solution and an initiator solution were added at the same ratio was charged. The monomer concentration at this time is 9.0%. After adding the monomer, react for 1 hour, then increase the temperature to 50 ° C.
The reaction was completed for 5 hours. The reaction rate was measured and found to be 99.0%. Further, the weight average molecular weight (DLS-7000 manufactured by Otsuka Electronics Co., Ltd.) was measured by static light scattering method to be 9,500. The results are shown in Table 1.

[0029]

[Example 3] 500 mL of 4 equipped with a thermometer, a stirrer, a nitrogen introduction tube, a monomer supply tube connected to a peristaltic pump (SMP-21 type, manufactured by Tokyo Rika Kikai) and a condenser
Ion-exchanged water (131.0 g) and acrylamide 50% aqueous solution (15.0 g) were charged into a two-necked flask to adjust the pH of the aqueous solution to 6.2. The monomer concentration at this time is 5%. The reactor was covered with a heater to raise the temperature to 80 ° C. and maintained at that temperature, and after nitrogen substitution for 30 minutes, 0.8 g of a 0.2% ammonium peroxodisulfate aqueous solution was used as an initiator (0.4% relative to the monomer, ) And 1.2 g of a 2.0% aqueous solution of sodium hydrogen sulfite (0.12% based on the monomer, 1:20 in redox equivalent ratio) were added respectively to initiate polymerization. One hour after the initiation of polymerization, the polymerization rate was measured by liquid chromatography and found to be 99.5%. Then, the acrylamide solution was added to 16.7 g of a 50% aqueous solution at a monomer concentration of 5% at the same ratio as the redox initiator solution to prepare a reactor.
Polymerization was continued in a nitrogen stream. 1 hour after adding the monomer solution,
When the reaction rate was measured by the same operation, it was 98.7%. Then, a solution prepared by adding an initiator solution in the same ratio as 36.6 g of 50% monomer was charged. At this time, the monomer concentration is 9.2%. After charging the monomer for the third time, 1
The reaction was carried out for an hour, then the temperature was lowered to 50 ° C., and the reaction was continued for another 5 hours to complete the reaction. The reaction rate was measured and found to be 99.5%. In addition, by the static light scattering method (DLS-700 manufactured by Otsuka Electronics)
0) The weight average molecular weight was measured to be 18,000. The results are shown in Table 1.

[0030]

[Example 4] 500 mL of 4 equipped with a thermometer, a stirrer, a nitrogen introduction tube, a monomer supply tube connected to a peristaltic pump (SMP-21 type, manufactured by Tokyo Rika Kikai) and a condenser
Ion-exchanged water 126.0 g, acrylamide 50% aqueous solution 4.2 g, and acrylic acid 60% aqueous solution 2.3 g were added to a two-necked flask, and 30 aqueous solutions of sodium hydroxide 2.
After neutralizing with 2 g, 12.1 g of acryloyloxyethyltrimethylammonium chloride (molar ratio was 50 mol%, 20 mol%, 30 mol% in this order) was charged to adjust the pH of the aqueous solution to 3.9. The monomer concentration at this time is 8
%. The reactor was covered with a heater, heated to 80 ° C., kept at this temperature and purged with nitrogen for 30 minutes, and then ammonium peroxodisulfate was added as an initiator.
2.4 g of 2% aqueous solution (0.4% to monomer) 1.3 g aqueous 2.0% sodium bisulfite solution (4.0% to monomer,
The redox equivalent ratio of 1:10) was added to each to initiate polymerization. One hour after the initiation of polymerization, the polymerization rate was measured by liquid chromatography and found to be 99.0%. After that, a monomer solution having the same molar ratio was used as a monomer concentration of 8
A solution prepared by adding 28.6 g of a 50% aqueous solution to the above-mentioned redox initiator solution at the same ratio so that the amount of the solution became 50% was charged into the reactor. One hour after the addition of the monomer solution, the reaction rate was measured by the same operation, and it was 98.0%. Then, a solution to which an initiator solution was added at the same ratio as 39.3 g of a 50% aqueous solution was charged. The monomer concentration at this time is 9.0%. After reacting for 1 hour, the temperature was lowered to 50 ° C. and the reaction was continued for another 5 hours to complete the reaction. The reaction rate was measured and found to be 99.5%. In addition, by static light scattering method (DLS-manufactured by Otsuka Electronics)
The weight average molecular weight was 14,500. The results are shown in Table 1.

[0031]

[Comparative Example 1] 500 mL of 4 equipped with a thermometer, a stirrer, a nitrogen introducing pipe, a monomer supply pipe connected to a peristaltic pump (SMP-21 type, manufactured by Tokyo Rika Kikai) and a condenser
Ion-exchanged water 130.0 g, acryloyloxyethyl trimethyl ammonium chloride 80 in a two-necked flask.
% Aqueous solution of 1% and 2.0 g of 50% aqueous solution of acrylamide were charged to adjust the pH of the aqueous solution to 4.5. The molar ratio of the monomers is 80:20 in the order of the previous monomers,
The monomer concentration is 8%. Cover the reactor with a heater and heat the solution to 80 ° C and keep it at that temperature.
After purging with nitrogen for 0 minutes, 1.2 g of a 0.2% ammonium peroxodisulfate aqueous solution (0.01% of monomer) and 0.9 g of a 2.0% sodium hydrogen sulfite aqueous solution (0% of monomer) were used as initiators. 0.05%, redox equivalent ratio 1:
5) was added to each to initiate polymerization. Polymerization start 1
After a lapse of time, the rate of polymerization was measured by liquid chromatography and found to be 98.0%. Then, a monomer solution having the same molar ratio was added to 28.6 g of a 50% aqueous solution so as to have a monomer concentration of 8% at the same ratio as the redox initiator solution ammonium peroxodisulfate. Similarly, the temperature in the reactor was kept at around 80 ° C. and the polymerization was continued in a nitrogen stream. One hour after the addition of the monomer solution, the reaction rate was measured by the same operation, and it was 98.8%. Then, a solution prepared by adding 39.3 g of a 50% aqueous solution and an initiator solution at the same ratio was charged. At this time, the monomer concentration was 9.
It is 0%. After charging the monomers for the third time, the reaction was allowed to proceed for an hour, then the temperature was lowered to 50 ° C., and the reaction was allowed to proceed for an additional 3 hours to complete the reaction. The final reaction rate was measured and found to be 98.7%. In addition, by the static light scattering method (DLS-7 manufactured by Otsuka Electronics)
000) Weight average molecular weight is measured 320,000
Met. The results are shown in Table 1.

[0032]

Comparative Example 2 500 mL of 4 equipped with a thermometer, a stirrer, a nitrogen introducing pipe, a monomer supply pipe connected to a peristaltic pump (SMP-21 type, manufactured by Tokyo Rikakikai) and a condenser.
Ion-exchanged water 130.0 g, acryloyloxyethyl trimethyl ammonium chloride 80 in a two-necked flask.
% Aqueous solution of 1% and 2.0 g of 50% aqueous solution of acrylamide were charged to adjust the pH of the aqueous solution to 4.5. The molar ratio of the monomers is 80:20 in the order of the previous monomers,
The monomer concentration is 8%. Cover the reactor with a heater and heat the solution to 60 ° C and keep it at that temperature.
After purging with nitrogen for 0 minutes, 1.2 g of a 0.2% ammonium peroxodisulfate aqueous solution (0.01% of monomer) and 0.9 g of a 2.0% sodium hydrogen sulfite aqueous solution (0% of monomer) were used as initiators. 0.1%, redox equivalent ratio 1: 1
0) was added to each to initiate polymerization. Polymerization start 1
After a lapse of time, the rate of polymerization was measured by liquid chromatography and found to be 98.0%. Then, a monomer solution having the same molar ratio was added to 28.6 g of a 50% aqueous solution so as to have a monomer concentration of 8% at the same ratio as the redox initiator solution ammonium peroxodisulfate. Similarly, the temperature in the reactor was kept at around 60 ° C. and the polymerization was continued in a nitrogen stream. One hour after the addition of the monomer solution, the reaction rate was measured by the same operation, and it was 98.8%. Then, a solution prepared by adding 39.3 g of a 50% aqueous solution and an initiator solution at the same ratio was charged. At this time, the monomer concentration was 9.
It is 0%. After charging the monomer for the third time, the reaction was allowed to proceed for an hour, then the temperature was lowered to 50 ° C., and the reaction was allowed to proceed for an additional 5 hours to complete the reaction. The final reaction rate was measured and found to be 98.7%. In addition, by the static light scattering method (DLS-7 manufactured by Otsuka Electronics)
000) The weight average molecular weight is measured to be 550,000.
Met. The results are shown in Table 1.

[0033]

Comparative Example 3 By the same operation as in Examples 1 to 4, the anionic water-soluble polymer was added at an equivalent ratio of reducing agent / redox of 1:
Then, a polymerization test was conducted. The results are shown in Table 1.

[0034]

Comparative Example 4 By the same operation as in Examples 1 to 4, an anionic water-soluble polymer was added at an equivalent ratio of reducing agent / redox of 1:
10. A polymerization test was conducted at a polymerization temperature of 60 ° C. The results are shown in Table 1.

[0035]

[Table 1] AAM: acrylamide, AAC: acrylic acid, DMQ: acryloyloxyethyltrimethylammonium chloride monomer concentration: mass%,

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08F 20/60 C08F 20/60 F term (reference) 4J011 NA11 NA39 NA40 NB02 4J015 CA02 CA03 CA04 4J100 AJ02P AJ08P AJ09P AL08P AL09P AM15P AM19P AM21P AQ07P BA14P BA32P BA55P CA01 CA04 CA05 DA01 DA38 FA04 FA08 FA37 FA39 JA01 JA57 JA67

Claims (9)

[Claims] 1. A monomer mainly comprising a monomer or a monomer mixture selected from one or more of water-soluble monomers represented by the following general formulas (1) to (4), at atmospheric pressure: At a temperature of 70 ° C. or higher and a temperature near the boiling point of the aqueous solution, polymerization is carried out by a redox system initiator in which the equivalent ratio in the redox reaction is set to the equivalent number of reducing agent / equivalent number of oxidizing agent = 10-50. A method for producing a water-soluble polymer characterized by the above. [Chemical 1] General formula (1) R1 is hydrogen, a methyl group or a carboxymethyl group, A is SO3, C6H4SO3, CONHC (CH3) 2CH
2SO3, C6H4COO or COO, R2 is hydrogen or COOY2, Y1 or Y2 is hydrogen or cation Formula (2) R3 is hydrogen or a methyl group, R4 and R5 are alkyl or alkoxyl groups having 1 to 3 carbon atoms, R6 is hydrogen, an alkyl group having 1 to 3 carbon atoms, an alkoxyl group, or a benzyl group. May be different, A is oxygen or N
H and B represent an alkylene group having 2 to 4 carbon atoms or an alkoxylene group, and X1 represents an anion. [Chemical 3] General formula (3) R7 is hydrogen or a methyl group, R8 and R9 are C1-C3 alkyl, an alkoxyl group, or a benzyl group,
X2 represents an anion, respectively. [Chemical 4] R10, Q is NHCOR11, R11 is hydrogen or a lower alkyl group, COABR12, A is NH or O, R1
2 represents hydrogen or a lower alkyl group. General formula (4) 2. The method for producing a water-soluble polymer according to claim 1, wherein a chain transfer agent is allowed to coexist in the aqueous solution. 3. The required amount of the monomer is divided into several times and added to the reaction solution while maintaining the total concentration of the monomer in the reaction solution at 2 to 10% by weight. The method for producing the water-soluble polymer according to claim 1. 4. The required amount of the monomer is continuously added to the reaction solution while keeping the total concentration of the monomer in the reaction solution at 2 to 10% by weight. 1
The method for producing a water-soluble polymer according to 1. 5. The method for producing a water-soluble polymer according to claim 1, wherein the water-soluble polymer is nonionic. 6. The method for producing a water-soluble polymer according to claim 1, wherein the water-soluble polymer is cationic or amphoteric. 7. The method for producing a water-soluble polymer according to claim 1, wherein the water-soluble polymer is anionic. 8. The weight average molecular weight of the water-soluble polymer is
It is 1000-200,000, The manufacturing method of the water-soluble polymer of Claim 1 characterized by the above-mentioned. 9. A redox system for a monomer mixture mainly comprising a monomer or a monomer mixture selected from one or more water-soluble monomers represented by the general formulas (1) to (4). The method for producing a water-soluble polymer according to claim 1, wherein the total amount of the initiator is 0.05 to 1% by mass.