JPH06322010A - Production of amphoteric water-soluble high-molecular compound - Google Patents

Abstract

(57) [Summary] [Objective] An amphoteric polymer compound having a high degree of polymerization and a narrow molecular weight distribution is used as a flocculating and dehydrating agent for sludge by a photopolymerization method. [Constitution] An aqueous solution (I) in which an aqueous solution comprising a water-soluble cationic monomer and a photopolymerization initiator is adjusted to pH 4.5 to 7.0 and the amount of dissolved oxygen is controlled, a water-soluble anionic monomer and the aqueous solution (I) are prepared. When mixed, an aqueous solution (II) containing an acid having an amount of pH of 4.0 to 1.8 and having a controlled dissolved oxygen amount is mixed, immediately supplied to a polymerization container, and irradiated with light to perform polymerization. A method for producing an amphoteric water-soluble polymer compound.

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 an amphoteric water-soluble polymer compound which is effective for aggregating and dehydrating sludge generated in various industrial wastewater treatment, sewage treatment, human waste treatment and the like.

[0002]

2. Description of the Related Art A method for producing an amphoteric water-soluble polymer compound is disclosed in JP-A-49-6078 and JP-A-53-1492.
92, JP-A-62-129200, JP-A-62-2
Many proposals have been made such as No. 05112 and Japanese Patent Laid-Open No. 3-18900.

However, since these are all batchwise polymerization processes carried out in a polymerization tank, the heat of polymerization is not sufficiently dissipated in order to maintain the property that the gel can be taken out from the polymerization tank, and the gel crushing is also performed. The upper limit of the monomer concentration is generally limited to about 30% because it is necessary to smoothly pass through the subsequent steps before the drying step.

Therefore, the productivity, particularly the drying efficiency, is poor and the productivity is poor. Further, since it is a batch system, it causes variations in quality between batches, non-uniformity of internal temperature, and deterioration of solubility of the obtained polymer compound due to high temperature during polymerization.

[0005]

Various proposals have been made for a method of polymerizing a polymerizable monomer solution by keeping it in a layered form and irradiating it with light from above. In the case of producing a cationic polymer, a known document (JP-A 61-155405) in which the pH of a monomer solution is regulated to 4 to 7 is found. Further, in the case of producing an anion / nonion type polymer, a known document (Japanese Patent Publication No. 56-15805) in which the pH of a monomer solution is 8 or higher is found. There is a known document (Japanese Patent Publication No. 61-23926) in which a pH of a monomer solution is 4 to 14 when a cationic or anionic / nonionic polymer is produced.

To produce amphoteric polymers, cationic monomers are constantly included in the monomer solution. in this case,
Since the cationic monomer undergoes a hydrolysis reaction on the alkaline side, the pH needs to be 7 or less. In order to obtain an amphoteric polymer, a cationic monomer and an anionic monomer must be contained, but the polymer obtained when photopolymerized at pH 4 to 7 has many insolubles in water and cannot be used as a water-soluble polymer. .

It is presumed that this is because the cation monomer and the anion monomer have already undergone a neutralization reaction before the polymerization and the polymer has a crosslinked structure. In order to prevent this reaction and suppress the dissociation of the carboxyl group in the anionic monomer molecule, the amphoteric system having excellent water solubility can be obtained by polymerizing the pH of the monomer solution at 4.0 or less, preferably 2.5 to 2.0. A polymer is obtained.

When the pH of the monomer solution is set to 4.0 or less, the monomer cannot be stored for a long time if nitrogen is blown or vacuum degassing is performed so that the dissolved oxygen in the solution becomes 1.0 ppm or less. Further, depending on the cationic monomer and composition used, thickening and heat generation may occur during deoxidation, and polymerization may occur. When a large amount of the monomer solution is prepared with respect to the capacity of the layered polymerization apparatus, it takes a long time to supply the monomer solution to the polymerization container. Therefore, it is essential that the monomer solution has good stability. A monomer solution containing a cation monomer and an anion monomer and having a low pH and a low dissolved oxygen content cannot maintain stability. The present invention has been made to form a technique which is completely free from the stability of the monomer solution.

[0009]

According to the present invention, an aqueous solution containing a water-soluble cationic monomer and a photopolymerization initiator is adjusted to pH 4.5.
Aqueous solution (I) in which the amount of dissolved oxygen is controlled to be adjusted to ˜7.0
And a water-soluble anion monomer and an aqueous solution (II) containing an amount of acid having a pH of 4.0 to 1.8 when the aqueous solution (I) is mixed and having a dissolved oxygen content controlled, and immediately mixed. The method for producing an amphoteric polymer compound is characterized in that polymerization is carried out by irradiating with light and irradiating with light.

When a photopolymerization initiator is added to a solution consisting of a predetermined amount of a water-soluble cationic monomer and a water-soluble anionic monomer in order to obtain an amphoteric water-soluble polymer compound and deoxidation is carried out, the stability of the solution decreases. Depending on the composition, a polymerization exotherm is seen during the deoxidation step. According to the research conducted by the present inventors, when both the specific pH and the dissolved oxygen concentration are satisfied, it is 250 to 6
It was found to initiate polymerization even when not irradiated with 00 nm light. Ie

If the pH of the aqueous solution of the water-soluble cation monomer and the photoinitiator, and that of the water-soluble anion monomer and the photoinitiator is 4.0 or less and the amount of dissolved oxygen is 2 ppm or less, the stability of the solution is lowered. The water-soluble anionic monomer has an extremely low p of pH 1.5.
Even if it is H, it is stable for a long time if the amount of dissolved oxygen is 2 ppm or more. Furthermore, in order to steadily advance the photopolymerization, the dissolved oxygen content of the monomer solution at the time of irradiation with light should be 1 pp.
It must be m or less. I understood that.

In view of the above three points, in order to perform stable photopolymerization for a long time, (I) a water-soluble cationic monomer, a photoinitiator, and if necessary, up to 98 parts by weight of a water-soluble nonionic monomer and a suitable Aqueous solution (I) consisting of additives and dilution water is added to pH 4.5-
When adjusted to 7.0 and the amount of dissolved oxygen is mixed with the following aqueous solution (II), it is 1 ppm or less, preferably 0.8 to 0.2 ppm.
Deoxidize so that (II) A water-soluble anionic monomer, if necessary, dilution water, and a pH when mixed with the aqueous solution (I) are 4.0 to 1.
8 A predetermined amount of non-volatile inorganic acid is added so that it is preferably 2.5 to 2.0, and the amount of dissolved oxygen is 2 ppm or more, and
To an amount of 1 ppm or less when mixed with the aqueous solution (I),
In some cases, deoxidation is not performed and deoxidation is performed if necessary. A water-soluble polymer compound can be obtained by uniformly mixing the aqueous solutions of (I) and (II) and immediately irradiating with light.

The present invention will be described in detail below. As the water-soluble cationic monomer used in the present invention, the compound (1) represented by the following general formula is used.

[0014]

[Chemical 4]

Specific examples of the compound (1) represented by the above general formula are the following 14 examples of monomers, which may be used alone or in combination of two or more kinds. (Meth) acrylic acid dimethylaminoethyl methyl chloride salt (meth) acrylic acid dimethylaminoethyl methyl bromide salt (meth) acrylic acid dimethylaminoethyl methylbenzyl chloride salt (meth) acrylic acid dimethylaminoethyl sulfate sulfate (meth) acrylic acid dimethyl salt Aminomethyl sulfate (meth) acrylic acid dimethylaminoethyl hydrochloride (meth) acrylaminopropyltrimethylammonium chloride salt

In the present invention, the water-soluble nonionic monomer that is optionally used as a monomer constituting the aqueous solution (I) is a compound (2) represented by the following formula, and specific examples thereof include acrylamide and methacrylamide. Can be mentioned. The monomer of the compound (2) may be used alone or in combination. The amount of the water-soluble nonionic monomer is determined by the cation degree (meq / g) required for the polymer compound to be finally obtained, but is usually 0.
~ 98 parts.

[0017]

[Chemical 5]

Most preferably, the commercially available products of the above-mentioned water-soluble cation monomer and water-soluble anion monomer are used as they are. These monomers are generally commercially available as an aqueous solution, and the concentration thereof is usually 70% to 85% for cationic monomers and 50% for nonionic monomers.

However, the aqueous solution (I) has a composition, a polymerization rate,
It may be diluted with water to a low concentration depending on the required physical properties and performance of the polymer compound. Since a lower concentration does not raise the temperature during polymerization, the molecular weight distribution is generally narrow, and the performance as a coagulant is high in some cases. In some cases, productivity may be prioritized. However, in order to smoothly pass through processes such as transfer and crushing, it is necessary to have a shape as a gel, and the composition has a great influence, but at least 15%, preferably 20% or more. If there is a margin in the process, it is possible to add monomer crystals and carry out polymerization at a high concentration. However, it is most advantageous to use a commercially available product undiluted.

The photopolymerization initiator used is 250 to 600 n.
A compound (3) represented by the following general formula is used as a general initiator that generates a radical by ultraviolet rays of m.

[0021]

[Chemical 6]

Specific examples of the compound (3) include benzoin methyl ether, benzoin ethyl ether,
Benzoin isopropyl ether, 2-hydroxy-2
-Methyl-1-phenylpropan-1-one, 1- (4
-Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, etc., and at least one of these is To use.

The photopolymerization initiator is added in the amount of the aqueous solution (I) and
When (II) is mixed, it is individually determined in the range of 2 to 1000 ppm by the light irradiation intensity, the monomer composition and concentration, the physical properties of the obtained polymer and the like. If a large amount of photopolymerization initiator is added, it will be affected by the lighting in the normal working environment and the uniformity of polymerization will be impaired, but the point that electricity is much cheaper than photoinitiator is It is preferable to consider. The water-insoluble photopolymerization initiator needs to be added after being dissolved in a water-soluble organic substance such as ethyl alcohol.

If necessary, the aqueous solution (I) may contain a generally used defoaming agent, a stripping agent, a chain transfer agent, a moating agent, a pH adjusting agent, a buffering agent, a grinding aid, etc. as an additive. Can be added.

Next, the aqueous solution (I) has a pH of 4.5.
It is adjusted to ˜7.0, preferably 5.0 or more. If the pH is high, stability is not a problem. Unadjusted pH rarely exceeds 7.0. If the pH is 4.0 or less, polymerization may start depending on the amount of dissolved oxygen even without irradiation with ultraviolet rays, so 4.5 or more, preferably 5.0 or more.
Need to keep above.

The aqueous solution (I) is deoxidized after adjusting the pH, and the amount of dissolved oxygen is preferably 1 ppm or less when the aqueous solution (I) and the aqueous solution (II) are mixed. Also, since the aqueous solution (II) is 2 ppm or more, the dissolved oxygen concentration and volume of the aqueous solution (II) are measured, and the dissolved oxygen amount after mixing is 1 ppm or less, preferably 0.8 to 0.2 ppm.
It is necessary to adjust so that

The water-soluble anionic monomer of the aqueous solution (II) is
In the compounds (4) and (5) represented by the following general formula, specific examples of the compound (4) include (meth) acrylic acid and itaconic acid, and specific examples of the compound (5) include 2-acrylamide-2-. Methyl propane sulfonic acid may be mentioned.

[0028]

[Chemical 7]

[Chemical 8]

The amount of the above water-soluble anionic monomer used is 0.5 to 35 parts by weight, preferably 2 to 25 parts by weight, relative to the cationic monomer in the aqueous solution (I). 0.5
When the amount is less than the amount, the amphoteric polymer compound does not exhibit amphoteric properties when used as a flocculant. Further, when it is used in excess of 35 parts, it is difficult to obtain a high molecular weight polymer,
In addition, the characteristics as amphotericity are deteriorated.

It is efficient to use the (meth) acrylic acid in the compounds (4) and (5) as a 25 to 50% aqueous solution. In addition, since 2-acrylamido-2-methylpropanesulfonic acid is commercially available as a solid, it is 20 to 3
It is preferred because it is easy to use as a 0% aqueous solution. The monomer concentration needs to be set so that the mixed solution of the aqueous solutions (I) and (II) has a target concentration, and may be diluted.

The pH of the aqueous solution (I) is adjusted to 4.5 to 7.0, and the pH of the mixed solution when it is mixed with the aqueous solution (II) needs to be 4.0 to 1.8. Aqueous solution (I
Add acid to I) and place. As the acid to be added, an inorganic and non-volatile one is preferable because the temperature may be high during the polymerization. Sulfuric acid, nitric acid and phosphoric acid are used for this.

The pH of the solution at the start of polymerization is 4.0 to 1.
It is preferably set to 8, particularly 2.5 to 2.0. When the pH is high, it is considered that the carboxyl groups of the anionic monomers of the compounds (4) and (5) are dissociated to form a salt with the cationic monomer, and the obtained polymer becomes insoluble in water.

From the relationship between the dissociation of the carboxyl group and pH,
The dissociation becomes almost 0 around pH 3.0. However, since there is a large variation in pH with respect to the amount of acid added and it is difficult to control the pH, if the acid is set to an excess side of 2.5 or less, the variation in pH due to the added amount is small, and the process control becomes easy. The mixed solution that has been deoxidized in the region where the pH is lower than 1.8 cannot maintain stability for a long time. Also pH
This is not necessary because an extremely high amount of acid is required to reduce it to 1.8 or less. A pH of 2.5 to 2.0 is substantially sufficient.

The amount of dissolved oxygen in the aqueous solution (II) must be kept at 2 ppm or more. Depending on the ratio of the amounts of the aqueous solutions (I) and (II) dissolved and the amount of dissolved oxygen in the aqueous solution (I), the amount of dissolved oxygen in the aqueous solution (II) is preferably 1.0 ppm or less when the aqueous solutions (I) and (II) are mixed. It is necessary to adjust the amount of dissolved oxygen so as to be 0.8 to 0.2 ppm. Therefore, in the mixed solution of the aqueous solutions (I) and (II), it may not be necessary to adjust the amount of dissolved oxygen.

The solutions (I) and (II) are kept at the same temperature. Usually 10 to 40 ° C, but 20 to 30 ° C
Is a range that is easy to handle. To lower the temperature to 20 ° C or lower, the cooling capacity must be increased. On the other hand, when the temperature is 30 ° C. or higher, evaporation of the anionic monomer increases and the polymerization rate becomes too high, which is not preferable in terms of the obtained polymer performance.

A solution prepared by mixing the prepared aqueous solutions (I) and (II) was immediately supplied to a polymerization container to which shower water having the same temperature as that of the prepared solution was applied from the lower part, and the upper surface was made of a transparent film with suppressed oxygen permeability. cover. From the viewpoint of heat resistance, tensile strength, availability, etc., this film is preferably a biaxially stretched product of polyethylene terephthalate and has a thickness of 10 to 25 μm and one side coated with about 2 μm of polyvinylidene chloride. In order to avoid contact between the mixed aqueous solution and the metal, it is preferable to lay a biaxially stretched polyethylene terephthalate film having a thickness of 10 to 25 μ on the bottom surface in the polymerization container.

Thickness (depth) of mixed solution in polymerization vessel
Is preferably 5 to 50 mm. When the thickness is large, the rate at which the heat of polymerization is transferred inside is slow and cannot be removed by cooling, and the heat of polymerization accumulates, resulting in a large temperature difference between the lower cooling surface and the upper cooling surface. Therefore, the difference in the physical properties of the polymer inside becomes large, resulting in a non-uniform product. Further, since the temperature becomes high, the internal heat transfer becomes the rate-determining factor for the polymerization, and the productivity rather decreases. When the thickness is less than about 5 mm, the ratio of the contact portion with the film on the lower surface and the upper surface increases, and the uniformity of the polymer decreases. In addition, productivity will naturally decrease. From the viewpoint of performance, it should be as thin as 5 mm or more and as thick as possible from the viewpoint of productivity, but it is preferably in the range of 10 to 30 mm.

In the polymerization, the dominant wavelength of light is 250 to 6 from the upper side.
Irradiate with a 00 nm chemical lamp. The irradiation intensity is set so as to be in the range of 0.1 to 50 W / m ^{2 on} the surface of the mixed solution, and is individually determined by the addition amount of the photopolymerization initiator, the monomer concentration, the molecular weight of the target polymer, the composition ratio, etc. .

It is possible to start the polymerization at an irradiation intensity of 0.1 W / m ² or less, but in this case, the polymerization is affected by the intensity of ultraviolet rays from irradiation in a general working environment, and therefore the polymerization is performed. It is not preferable because the device needs to be shielded and monitoring and inspection become more difficult. Irradiation intensity is up to about 50 at the shortest distance by arranging ordinary chemical lamp equipment.
W / m ² . After completion of the polymerization, the product is peeled off from the belt, and then subjected to usual crushing, drying and crushing, and then used as a product.

[0040]

【Example】

Example 1 As a polymerization solution, a cationic monomer aqueous solution (I) and an anionic monomer aqueous solution (II) having the following components and ratios were prepared. A: Cationic monomer aqueous solution (I) (a) Acrylic acid dimethylaminoethyl methyl chloride salt 80% aqueous solution 1019 g (b) Acrylamide 50% aqueous solution 181 g (c) 2-Hydroxy-2-methyl-1-phenylpropan-1-one 10% methoxyethoxyethanol solution 1 ml (d) Ethylenediaminetetraacetic acid disodium salt 5% aqueous solution 4 ml (e) Water 800 g (f) Phosphorous acid 10% aqueous solution 2 ml (g) Hyamine 1622 (release agent, manufactured by Rohm & Hass) 5 ml B: Anionic monomer aqueous solution (II) (h) Acrylic acid 50% water-soluble liquid 82 g

The above cationic monomer aqueous solution (I) was placed in a brown 2000 ml glass container, and nitrogen gas of 5 liters / minute was blown at 20 ° C. per liter of the solution to deoxidize the solution so that the dissolved oxygen content was 0. 0.5 ppm. The pH of this solution was 6.0. On the other hand, a solution obtained by mixing the anionic monomer aqueous solution (II) with the anionic monomer aqueous solution (II) and the cationic monomer aqueous solution (I) (hereinafter, a solution obtained by mixing the cationic monomer aqueous solution (I) and the anionic monomer aqueous solution (II) This is referred to as a "monomer solution"), and 0.2 ml of 98% sulfuric acid having a pH of 5.0 is added and the temperature is maintained at 20 ° C. The dissolved oxygen concentration was 7 ppm. The amount of sulfuric acid added to the anionic monomer aqueous solution to obtain a polymerization solution having a predetermined pH is the amount of sulfuric acid-pH calibration curve previously determined for the mixed solution of the monomer aqueous solutions (I) and (II). Decided from.

Next, the anionic monomer aqueous solution (II) was added to and mixed with the cationic monomer aqueous solution (I). The amount of dissolved oxygen in the obtained monomer solution was 0.8 ppm.
This monomer solution was used to evaluate the stability of the solution and the performance of the polymer obtained by polymerization.

(1) Stability of Polymerization Solution A part (50 ml) of the above-mentioned polymerization solution was put in a brown 100 ml Erlenmeyer flask replaced with nitrogen and immersed in a constant temperature water bath at 30 ° C. to increase the viscosity of the solution. It was judged with the naked eye. The results are shown in Table 1.

(2) Evaluation of performance of polymer Thickness of 1 mm on the inner surface of a stainless steel container having a weir made of rubber so as to have a length of 230 mm × width of 230 mm × depth of 20 mm.
Spread 0μ polyethylene terephthalate film,
The top surface was coated with 4μ vinylidene chloride resin and 10μ
Was covered with a polyethylene terephthalate film (1) to form a space (cell) having a thickness of about 20 mm for injecting the polymerization solution. After replacing this space with nitrogen, the monomer solution was injected. The amount was about 1,300 g.

While spraying water at 20 ° C. from below onto the lower surface of the container, a chemical lamp (from Mitsubishi Electric Corp.)
Irradiation) with an irradiation intensity of ² W / m ^{2 on} the upper film surface until the internal temperature rises by 2 ° C., and then with an intensity of 0.5 W / m ² , the polymerization temperature at the center of the container reaches a peak (72
℃), hold for another 30 minutes, then 50W
Irradiation was performed for 10 minutes at an irradiation intensity of / m ² to complete the polymerization.

The polymer gel was taken out of the container, crushed,
It was dried so that the water content was 7% or less, pulverized with a Willey pulverizer, and a product passing through a 20-mesh sieve was collected as a sample. 5 g of this sample was immersed in 495 g of pure water,
The mixture was stirred at 0 to 260 rpm for 4 hours, 5.84 g of sodium chloride was added, and the mixture was further stirred for 30 minutes. It was measured with a Brookfield viscometer as a 1% salt solution viscosity. Then 80 it
It was transferred to a mesh sieve, and the weight of the gel remaining on the sieve was measured as insoluble matter. The results are shown in Table 2.

Thereafter, the pH of the polymerization solution was adjusted to 4.
98 to be 0, 3.0, 2.5, 2.0, 1.8
% Sulfuric acid at 0.35, 0.53, 0.70, 0.
90, 1.4 ml was added, and the stability of the solution and the performance of the polymer were evaluated. The results are shown in Table 1 and Table 2, respectively.

[0048]

[Table 1]

[0049]

[Table 2]

Example 2 As a polymerization solution, a cationic monomer aqueous solution (I) and an anionic monomer aqueous solution (II) having the following components and ratios were prepared. A: Cationic monomer aqueous solution (I) (a) Methacrylic acid dimethylaminoethyl methyl chloride salt 80% aqueous solution 2000 g (b) Benzoin ethyl ether 10% methoxyethoxyethanol solution 4 ml (c) Ethylenediaminetetraacetic acid disodium salt 5% aqueous solution 4 ml (D) Polyethylene glycol # 6000 8 g B: Anionic monomer aqueous solution (II) Acrylic acid 50% aqueous solution 64 g

The above cationic monomer aqueous solution (I) was placed in each of 7 brown 2000 ml glass containers.
Nitrogen gas was blown at a rate of 5 liters / minute per 1 liter of the solution at 0 ° C., and the amount of dissolved oxygen in the solution was 2.0, 1.
Deoxidation is performed so as to be 5, 1.0, 0.7, 0.5, 0.2 (ppm). On the other hand, each of the anionic monomer aqueous solution (II) was placed in seven glass 200 ml containers,
1.4 ml of 98% sulfuric acid is added so that the pH of the polymerization solution is 2.0. Then, polymerization was carried out in the same manner as in Example 1. However, the temperature of water sprayed from below the container during polymerization was 30 ° C., the initial irradiation intensity was 8 W / m ^2, and the internal temperature of the polymerization container reached a peak (105 ° C.) and then held for 10 minutes. Then, 50 W / m ^{2 was} irradiated for 10 minutes to complete the polymerization. In the same manner as in Example 1, coarse crushing, drying, crushing and sieving were carried out for evaluation. The results are shown in Table 4. Table 3 shows the stability of the polymerization solution.

[0052]

[Table 3]

[0053]

[Table 4]

Example 3 The following monomer solution is prepared. A: Cationic monomer aqueous solution (I) (a) 70% dimethylaminoethyl methacrylate aqueous solution 1482 g (b) 50% acrylamide aqueous solution 518 g (c) 2-hydroxy-2-methyl-1-phenylpropan-1-one 10% methoxyethoxyethanol solution 2 ml (d) ethylenediaminetetraacetic acid 2-sodium salt 5% aqueous solution 4 ml (e) phosphorous acid 10% aqueous solution 4 ml (f) hyamine 5 ml B: anionic monomer aqueous solution (II) (g) acrylic acid 50 % Water-soluble liquid 207g

The above cationic monomer aqueous solution (I) was added to 30
Warm to ° C and divide into 6 equal parts. The pH at this time was 5.26. 5% caustic soda 0.2 was added to each of the 6 equal parts.
1 ml, 10% sulfuric acid 0.12 ml, 10% sulfuric acid 0.34
ml, 25% sulfuric acid 0.20 ml, 25% sulfuric acid 0.48 m
1 and 0.88 ml of 25% sulfuric acid are added to obtain pH values of 6.0, 5.0, 4.0, 3.0, 2.5 and 2.0, respectively. Nitrogen gas was blown into the solutions having these pH values in the same manner as in Example 1 to adjust the dissolved oxygen amount in each solution to 0.
Stability was examined by adjusting the concentration to 5 ppm, sealing the container, and immersing it in a constant temperature water bath at 30 ° C. The results are shown in Table 5.

[0056]

[Table 5]

On the other hand, the aqueous solution of the cationic monomer [I] having the above composition was heated to 30 ° C. and nitrogen gas was blown thereinto in the same manner as in Example 1 to adjust the dissolved oxygen amount to 0.5 ppm. In addition, the anion monomer aqueous solution [II] of the above composition, the pH of the polymerization solution
1.2 ml of 98% sulfuric acid is added so that the ratio becomes 2.0. The solution temperature is set to 30 ° C., and nitrogen gas is blown into the solution to adjust the dissolved oxygen amount to 2.0 ppm.

Next, a weir having a height of 20 mm is provided at both ends,
Distance between weirs is 200 mm, effective belt length is 1200
mm thickness of stainless steel endless belt 1
A 0 μm polyethylene terephthalate film was continuously supplied, and 350 ml / min of the above cationic monomer aqueous solution [I] and 5 anionic monomer aqueous solution were applied onto this film.
The polymerization solution, which was continuously fed and mixed at a rate of 0 ml / min, was poured into a nitrogen atmosphere and a thickness of 10
A film in which 4 μ of polyvinylidene chloride was applied to a μ polyethylene terephthalate film was continuously supplied and covered. The belt speed was 100 mm / min.

A fluorescent chemical lamp (manufactured by Mitsubishi Electric Corporation) was irradiated from above with the illuminance set under the following conditions. Belt length from 0 to 200 mm from the polymerization solution injection side:
5 W / m ² , belt length 200 ~ from the monomer solution injection side
Between 1000 mm: 1 W / m ² , belt length from the monomer solution injection side between 1000 and 1200 mm: 50 W / m ² . In the above irradiation, the irradiation intensity was adjusted so that the surface temperature of the film at the exit of the belt length of 200 mm increased by 5 to 10 ° C. The surface temperature at the intermediate portion of the belt length at the time of the steady state was 70 to 75 ° C.

After peeling the sheet-like gel polymer having a thickness of about 20 mm taken out from the photopolymerizer from the film,
The pieces were cut, and then crushed, dried, crushed, and sieved in the same manner as in Example 1. The viscosity of a 1% aqueous salt solution of the obtained polymer is 260 mP.
The amount of insoluble gel was 2.2 g, which was a small amount.

Example 4 The following was used as an aqueous monomer solution. A: Cationic monomer aqueous solution [I] (a) Acrylamidopropyltrimethylammonium chloride salt 70% aqueous solution 714 g (b) Acrylamide 50% aqueous solution 1000 g (c) 2-Hydroxy-2-methyl-1-phenylpropan-1-one 10 % Methoxyethoxyethanol solution 2 ml (d) Ethylenediaminetetraacetic acid-2-sodium salt 5% aqueous solution 4 ml (e) Phosphorous acid 10% aqueous solution 4 ml (f) Hyamine 5 ml (g) Water 130 g B: Anion monomer aqueous solution (h) Acrylic Acid 50% aqueous solution

Nitrogen gas is blown into the above cationic monomer aqueous solution (I) to adjust the amount of dissolved oxygen to 0.6 ppm. p
H was 6.5. Then, the cationic monomer aqueous solution (I) and sulfuric acid for pH adjustment are adjusted so that the weight ratio of the cationic monomer (acrylamidopropyltrimethylammonium chloride salt) / anionic monomer (acrylic acid) and the pH of the polymerization solution are as shown in Table 6. And anionic monomer aqueous solution (II) containing are mixed and polymerized in the same manner as in Example 1. However, the irradiation intensity of the chemical lamp is 2.0 W /
m ² and 10 minutes after showing the peak temperature (75 ° C.),
Irradiation was performed for 10 minutes at an intensity of 50 W / m ² . The performance of the obtained polymer is shown in Table 6.

[0063]

[Table 6]

Example 5 Using the 0.2% aqueous solution of the polymer obtained in Example 3,
The performance was evaluated by the sludge in the food manufacturing process. Table 7 shows the analysis values of the sludge used for the evaluation.

[0065]

[Table 7]

4 liters of the above sludge was placed in a 5 liter container, and 1 part of polyaluminum chloride was added to the evaporation residue.
0% and 1.10% of the polymer were added, and the mixture was stirred with a stirrer for 1 minute. Belt width 20 cm, filtration unit 60 cm,
Using a small belt press dehydrator with a contact length of 30 cm with the roll, the belt speed is 30 cm / min and the pressure at the belt is 1 k.
It was set to be g / cm ² . The sludge after stirring was supplied to the dehydrator at a rate of 1 liter / minute. The cake after dehydration was sampled and the water content was measured. Water content is 8
It was 2.0%. The floc strength before dehydration was large and tight, and the cake was firm and excellent.

[0067]

INDUSTRIAL APPLICABILITY The present invention has a depth of 50 m in a polymerization vessel.
An amphoteric water-soluble polymer compound is obtained by controlling the temperature during polymerization of a monomer solution of m or less by light intensity and cooling.
The concentration of the monomer that can be used in the present invention is 15% or more as a general concentration at which the gel property at the time of completion of polymerization is maintained, and the monomer is used up to the concentration at which it is maintained as an aqueous solution. On the high concentration side, a commercially available monomer may be used undiluted, and in some cases, a crystalline monomer may be added to produce a high concentration up to about 90%. Furthermore, according to the present invention, since the temperature during the polymerization is controlled and the polymerization is carried out at a high concentration, the molecular weight of the obtained amphoteric polymer compound can be increased and the molecular weight distribution can be narrowed. The performance is improved. Further, because of the high concentration, the drying load is remarkably reduced, the productivity is improved, and the production cost is greatly reduced.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location C08F 220/06 MLU 7242-4J 220/34 MMR 220/56 MNC 220/60 MNH

Claims (5)

[Claims] 1. An aqueous solution comprising a water-soluble cationic monomer and a photopolymerization initiator adjusted to pH 4.5 to 7.0 to control the amount of dissolved oxygen (I), a water-soluble anionic monomer and the aqueous solution (I). ) Is mixed and the pH is 4.0 to 1.
An aqueous solution (I
A method for producing an amphoteric water-soluble polymer compound, which comprises mixing I), immediately supplying it to a polymerization container, and irradiating it with light to carry out polymerization. 2. The method according to claim 1, wherein at least one compound represented by the following general formula is used as the water-soluble cationic monomer. [Chemical 1] 3. The method according to claim 1, wherein at least one compound represented by the following general formula is used as the water-soluble anionic monomer. [Chemical 2] [Chemical 3] 4. The water-soluble anionic monomer of the aqueous solution (II) is added to the water-soluble cationic monomer of the aqueous solution (I) at 0.5.
The manufacturing method according to claim 1, wherein the mixing is performed at a ratio of about 35 parts by weight. 5. The dissolved oxygen content of the aqueous solution (II) is controlled to 2 pp in controlling the dissolved oxygen content of the aqueous solution (I) and the aqueous solution (II).
The amount of dissolved oxygen in each of the aqueous solution (I) and the aqueous solution (II) is adjusted so that the amount of dissolved oxygen in the aqueous solution immediately after mixing the aqueous solution (I) and the aqueous solution (II) is 1.0 ppm or less. The manufacturing method according to claim 1, wherein: