JPS5946247B2 - Production method of acrylamide water-soluble polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to acrylamide or a mixture of acrylamide and other polymerizable monomers copolymerizable with the acrylamide (
This invention relates to a novel method for producing a water-soluble polymer by polymerizing (hereinafter abbreviated as acrylamide monomer).

Acrylamide homopolymers and acrylamide copolymers (hereinafter collectively referred to as P-AAM), especially P-AAM with a high degree of polymerization, are used for various wastewater treatment, chemical industry, mining industry processes, and prevention of turbid water during dredging. Recently, the demand for water-soluble polymers for use in water-soluble polymers has increased rapidly.

In particular, when used for the above-mentioned waste water treatment and turbid water prevention purposes, acrylamide water-soluble polymers are desired to have a large flocculating effect and good water solubility.

Therefore, as a method for obtaining P-AAM that exhibits such aggregation effect and has good water solubility, conventionally, acrylamide monomers are polymerized in the presence of a polymerization initiator of persulfate and sulfite compounds. Although a method is commonly used, this method does not involve polymerizing acrylamide-based monomers in the presence of actively added amounts of copper ions, as described later in this application.

As a result of intensive research, the present inventors have found that by performing the polymerization reaction in the presence of a predetermined amount of copper ions together with the polymerization initiator, the P obtained
- The present invention was achieved by discovering the surprising fact that the aggregation effect and water solubility of AAM are significantly improved.

That is, the present invention uses a persulfate and a sulfite compound as a polymerization initiator when polymerizing an acrylamide monomer in a method for producing an acrylamide water-soluble polymer, and copper ions are added to the polymerization initiator. 0.10 pμ in weight ratio to the acrylamide monomer used
This is a method for producing an acrylamide-based water-soluble polymer, characterized in that the acrylamide-based water-soluble polymer is present in an amount of m or more. The present invention will be explained in more detail.

The present invention is applied to the homopolymerization of acrylamide or the copolymerization of acrylamide and a polymerizable monomer copolymerizable with the acrylamide. For example, methacrylamide, methylolacrylamide, methacrylic acid, acrylic acid, or water-soluble salts and esters thereof, acrylonitrile,
Examples include dimethylaminoethyl acrylate, methyl chloride quaternary salt of dimethylaminoethyl methacrylate, and dimethyl sulfate quaternary salt of diethylaminoethyl methacrylate.

Next, regarding persulfates and sulfite compounds used as polymerization initiators, persulfates include, for example, potassium persulfate, sodium persulfate, and ammonium persulfate. It is usually in the range of 06001 to 1.0% by weight based on the body, and 0.001
~0.05% by weight is preferable, and the sulfite compounds include various compounds such as dithionite, sulfite, thiosulfite, pyrosulfite, and thiosulfate, and typical examples of these compounds include, for example. ammonium dithionite,
Sodium dithionite, sodium sulfite, potassium sulfite, ammonium sulfite, sodium bisulfite,
Potassium bisulfite, ammonium bisulfite, methyl thiosulfite, ethyl thiosulfite, sodium pyrosulfite, potassium pyrosulfite, ammonium pyrosulfite, sodium thiosulfate, potassium thiosulfate,
There are ammonium thiosulfate, sodium formaldehyde sulfoxylate, etc. Among them, sodium hydrogen sulfite is particularly preferred, and the amount of the sulfite compound used is 0.1 to 10 molar ratio per 1.0 mol of persulfate. is preferably 0.25 to 1.0 molar ratio.

Next, the copper ion is preferably added as an aqueous solution in the form of a water-soluble monovalent or divalent copper compound such as copper nitrate, copper sulfate, or copper acetate, and the amount used is the same as that of the polymerization monomer used in the present invention. 0.10 ppm or more can be used, but especially 0.15
~1.5 ppm is preferred.

In addition, P-, which exhibits a flocculating effect and has good water solubility,
In the polymerization to obtain AAM, the amount of the polymerization initiator per 17 acrylamide monomers for polymerization was 1 x 10-47
The polymerization initiation temperature used in the case of the above-mentioned conventional method is 40°C, whereas in the case of the present invention, for example, in addition to the above-mentioned amount of polymerization initiator, copper ions are added to When using .2 ppm, the temperature was 20°C. Moreover, in comparing the two methods, the present invention has extremely superior flocculation performance and water solubility of the obtained P-AAM, and from this point of view as well, the present invention is superior. It is clear that it has great practical value. The polymerization temperature used in the present invention is generally 5 to 60°C. The polymerization method in the present invention includes aqueous solution polymerization, water-in-oil emulsion polymerization, etc., and is not particularly limited, but in the case of a high concentration aqueous solution of 10% or more, it is preferable to polymerize under adiabatic conditions.

Generally, acrylamide is produced by reacting acrylonitrile, water, and sulfuric acid to form acrylamide sulfate.
Although there is a method of neutralizing acrylonitrile with ammonia, recently a method of directly hydrating acrylonitrile in the presence of a metal-containing catalyst such as metallic copper has been widely adopted. It is treated with an exchange resin, anion exchange resin, etc. to remove ionic compounds, purified, and sold as a product in the form of an aqueous solution or crystal.

When using a metallic copper-based catalyst, a very small amount of copper ions may remain even after the above treatment, but the copper ions are usually 0.0% by weight relative to acrylamide.
It is about 0.01 to 0.03 ppm and does not exceed 0.05 ppm. In the present invention, acrylamide or a mixture of acrylamide and a polymerizable monomer copolymerizable with the acrylamide is used. On the other hand, the weight ratio of copper ions is 0.1
On the other hand, if copper ions are present in the polymerization system of the acrylamide monomer in an amount of less than 0.10 ppm by weight, The aggregation properties and water solubility of P-AAM are poor, and the aggregation properties and water solubility of P-AAM obtained by polymerizing an acrylamide monomer without substantial presence of copper ions in the polymerization system are shown. In some cases, the practical value becomes unsatisfactory.

P-AAM obtained according to the present invention can be used for treating various wastewater such as sewage, for treating paper, for thickening agents, etc., and is particularly suitable for treating various wastewater. Further, the P-AAM obtained by the present invention may be further treated with formaldehyde,
It is also possible to use it for similar purposes after reacting with dimethylamine. Next, examples of the present invention and reference examples corresponding thereto will be described. The acrylamide monomer used in each of these examples and reference examples was produced using a copper catalyst among the production methods described above. It was synthesized by direct hydration from the acrylonitrile used, and the synthesis reaction system contained 0.02 ppm of copper ions.

Example 1 A 20% by weight acrylamide-containing aqueous solution 3007 was placed in a flask and the inside of the system was placed under a nitrogen atmosphere.
(dissolved in 100 ml of water) and 1 ml of sodium hydrogen sulfite aqueous solution (140 η of sodium hydrogen sulfite dissolved in 100 ml of water) were added, and 0.20 p per monomer of the above acrylamide was added as a copper nitrate aqueous solution.
pm was added and polymerized for 60 minutes at 40°C, and the obtained acrylamide polymer gel was further dehydrated with methanol and then dried with hot air at 100°C for 1 hour to obtain a dry product.

Example 2 Ammonium persulfate and sodium hydrogen sulfite were added to 20% by weight acrylamide-containing aqueous solution 3007 in the same manner as in Example 1, and the same amounts as shown in Example 1 were used, and the above-mentioned acrylamide was added to this as an aqueous copper sulfate solution. The acrylamide polymer gel obtained by adding 0.60 ppm per monomer and polymerizing at 40'C for 60 minutes was dried in the same manner as in Example 1.
Example 3 20% aqueous solution containing 547 acrylamide and 67 methylol acrylamide 300
7 into a flask, put 1 ml of potassium persulfate aqueous solution (729 liters of potassium persulfate dissolved in 100 ml of water) and 1 ml of sodium bisulfite aqueous solution (140 liters of sodium hydrogen sulfite in 1 ml of water) under a nitrogen atmosphere inside the system.
0.00 ml of water) was added, and 0.20 ppm was added as a copper nitrate aqueous solution based on the total amount of the above acrylamide and methylol acrylamide.
After polymerization for 0 minutes, the obtained acrylamide-methylol acrylamide copolymer gel was dried in exactly the same manner as in Example 1.

Reference Example 1 300y of a 20% by weight acrylamide-containing aqueous solution was placed in a flask, the system was placed under a nitrogen atmosphere, and 1ml of an ammonium persulfate aqueous solution (ammonium persulfate 616~1
00 ml of water) and 1 ml of sodium bisulfite aqueous solution (140 to 10 ml of sodium bisulfite dissolved in
(dissolved in 0 ml of water) was added and polymerized at 40°C for 60 minutes, and the obtained polymer gel was further dehydrated with methanol and then dried with hot air at 100°C for 1 hour to obtain a dried product.

Test Results Table 1 shows the water solubility, flocculation performance, and polymerization conditions of the dried products obtained in Examples 1 to 3 and Comparative Example 1.

(1) Water solubility is measured by weighing a 0.1% aqueous solution of the dried polymer obtained in the above examples onto a 200-mesh cloth, and determining whether a gel-like substance remains after filtration. I determined whether or not there was.

In the above table, the mark ▲ indicates that the excess performance is good and no gel-like substances are observed.

The mark △ indicates that the filtration performance was poor and some gel-like substances were observed.

An x mark indicates that the filtration performance was poor and a gel-like substance was observed.

(2) The flocculation ability in the above table is calculated by adding 400 ppm of sulfuric acid to kraft pulp wastewater at pH 6, and adding the dried product of each polymer obtained in the above examples to 1 ppm of monomer ratio to the above wastewater.
The flocs were added and flocculated using a shear tester in a conventional manner, and judgment was made based on the size of the flocs produced.

In the above table, the circle mark indicates that flocs with a diameter of 3 to 4 mm are formed.

The △ mark indicates that a floc with a diameter of 1 to 3 mm is formed.

An x mark indicates that a floc with a diameter of less than 1 mm is formed.

The mark XX indicates that no floc was formed.

Claims (1)

[Claims] 1. In a method for producing an acrylamide-based water-soluble polymer, when acrylamide or a mixture of acrylamide and a polymerizable monomer that can be copolymerized therewith is polymerized, a persulfate and a sulfite-based compound are used as a polymerization initiator. Copper ions are added to the acrylamide or the mixture of acrylamide and a polymerizable monomer that can be copolymerized with the acrylamide in an amount of 0.10 p by weight.
1. A method for producing an acrylamide-based water-soluble polymer, characterized in that the acrylamide-based water-soluble polymer is present in an amount of pm or more.