JPH06329866A - Aqueous solution composition of cationic polymer at high concentration - Google Patents

Abstract

PURPOSE:To obtain the subject composition, composed of a cationic polymer having a specific structural unit, an inorganic salt and water, having a lower solution viscosity at a higher concentration than those 6f a conventional product and capable of improving the handleability and reducing the transportation cost. CONSTITUTION:The objective composition is composed of (A) a cationic polymer containing >=10mol% constituent unit expressed by the formula (R<1> is H or methyl; R<2> is methyl or ethyl; R<3> is benzyl; X<-> is anion; A is NH or O; B is CH2, C3H6, etc.), (B) an inorganic salt (e.g. NaCl) and (C) water. The content of the component (A) is >=5wt.% and the solution viscosity of the composition at 25 deg.C is <=100000cP. Furthermore, the component (A) is obtained by copolymerizing, e.g. dimethylaminoethyl acrylate quaternized with methyl chloride and dimethylaminoethyl acrylate quaternized with benzyl chloride which are cationic monomers capable of forming a unit expressed by the formula with acrylamide that is a nonionic monomer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a high-concentration aqueous solution composition of a cationic polymer, and more specifically, it has a low solution viscosity and a high concentration as compared with a conventional high-concentration liquid product of a water-soluble polymer. It is possible to improve the quality and reduce the transportation cost. For example, it is possible to increase the amount of the cationic polymer that is preferably used as a coagulant for wastewater treatment, a dehydrating agent for sludge treatment, a drainage improver for papermaking, and a yield improver such as filler. It relates to a concentrated aqueous solution composition.

Conventionally, a cationic high molecular weight polymer has been widely used as a coagulant for wastewater treatment, a dehydrating agent for sludge treatment, an additive (drying agent, filler retention improving agent) in the papermaking process, and the like. There is. However, since most of them are powdered polymers, (1) dissolution work takes time,
(2) The time required for dissolution is 1 to 2 hours,
(3) Solidification (blocking) easily occurs due to moisture absorption, (4) Dust is generated, which is not preferable in the work environment.
There are problems such as. In order to improve such problems,
Liquid polymer products such as water-in-oil emulsion polymers (Japanese Patent Publication No. 52-39417, JP-A-56-6)
2802), water-soluble polymer dispersions (JP-A 61-123610, JP-A 61-138607).
No. gazette) is proposed. However, the former water-in-oil emulsion polymer is obtained by emulsifying minute droplets of a high-concentration aqueous solution of a water-soluble polymer in a solvent that does not dissolve the water-soluble polymer such as mineral oil. Although it is a polymer and its handling properties have been improved compared to powder polymers, such as reduction of dissolution work,
Since it is basically a heterogeneous dispersion liquid, it tends to cause aggregation and sedimentation of particles, which causes a problem in product stability. Further, since it contains a large amount of organic solvent such as mineral oil, the product has a solvent odor, which is not preferable in the working environment. On the other hand, the latter water-soluble polymer dispersion is a specific material of water-soluble polymer,
Dispersed in an aqueous solution containing a large amount of salt in an insoluble state, unlike the above-mentioned emulsion polymer, since no organic solvent is used, there is no problem in the working environment, but the polymer in an insoluble state Since it is a dispersion liquid, it undergoes significant sedimentation and separation, and is not yet satisfactory in terms of product stability, and improvements are required. Further, even if the existing cationic polymer is used in the form of an aqueous solution, the above problem can be solved, but the cationic polymer used as an aggregating agent or an additive in the papermaking process has a high molecular weight, and the aqueous solution concentration cannot be increased. Therefore, it is currently not practical in terms of economy.

[0003]

Under the circumstances described above, the present invention has a low solution viscosity and a high concentration as compared with a conventional liquid product having a high concentration of a water-soluble polymer, and has an improved handling property. A high-concentration aqueous solution of a cationic polymer that can reduce transportation costs and is preferably used as, for example, a coagulant for wastewater treatment, a dehydrating agent for sludge treatment, a drainage improving agent for papermaking, or a yield improving agent such as a filler. It was made for the purpose of providing a composition.

[0004]

The inventors of the present invention have conducted intensive studies to develop a high-concentration aqueous solution composition of a cationic polymer having the above-mentioned preferable properties, and as a result, have studied the cationic polymer having a specific constitutional unit. It was found that the object can be achieved by an aqueous solution composition containing at least a certain concentration and an inorganic salt and having a solution viscosity at a temperature of 25 ° C. of 100,000 centipoises or less, and the present invention is completed based on this finding. Came to. That is, the present invention has the general formula

[0005]

[Chemical 3]

(Wherein R ¹ is a hydrogen atom or a methyl group, R ²
Is a methyl group or an ethyl group, R ³ is a benzyl group, X ⁻ is an anion, A is —NH— or —O—, and B is

[0007]

[Chemical 4]

A cationic polymer containing 10 mol% or more of a constitutional unit represented by the formula), an inorganic salt and water, and 5% by weight of the cationic polymer.
The present invention provides a high-concentration aqueous solution composition of a cationic polymer, which contains the above and has a solution viscosity of 100,000 centipoise or less at a temperature of 25 ° C.

The present invention will be described in detail below. The cationic polymer used in the composition of the present invention has the general formula

[0010]

[Chemical 5]

( ¹ ) wherein R ¹ , R ² , R ³ , X ⁻ , A and B have the same meanings as defined above. Examples of the cationic monomer forming the structural unit represented by the general formula [1] include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide. , Benzyl chloride, benzyl iodide of vinyl monomers having amino groups such as diethylaminopropyl acrylamide and diethylaminopropyl methacrylamide.
Examples thereof include quaternary compounds such as benzyl bromide. These cationic monomers may be used alone or in combination of two or more. The cationic monomer may be copolymerized with another copolymerizable cationic monomer or nonionic monomer. Examples of the other cationic monomer include those represented by the general formula

[0012]

[Chemical 6]

(Wherein R ⁴ is a hydrogen atom or a methyl group, R ⁵
Is a methyl group or an ethyl group, R ⁶ is a hydrogen atom, a methyl group,
Ethyl group or propyl group, Z ^- is an anion, D is -NH
-Or-O-, E is

[0014]

[Chemical 7]

And a group represented by the following). Specific examples of the cationic monomer represented by the general formula [2] include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate,
Methyl chloride, ethyl chloride, propyl chloride of vinyl monomers having amino groups such as diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide, diethylaminopropyl acrylamide, and diethylaminopropyl methacrylamide.
Quaternary compounds with methyl iodide, ethyl iodide, propyl iodide, methyl bromide, ethyl bromide, propyl bromide, dimethylsulfate, diethylsulfate, etc., or hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, propionic acid, etc. And a tertiary salt thereof can be mentioned. These cationic monomers may be used alone or in combination of two or more. On the other hand, examples of the nonionic monomer include acrylamide, methacrylamide, N-methylacrylamide, N, N-dimethylacrylamide, acrylonitrile, styrene, and (meth) acrylic acid esters. These may be used alone or in combination of two or more.

The cationic polymer used in the composition of the present invention is required to contain the constituent unit represented by the general formula [1] in an amount of 10 mol% or more. When the cationic monomer unit contains a unit derived from the monomer represented by the general formula [2] together with the structural unit represented by the general formula [1], the constitution represented by the general formula [1] When the content of the unit is [A] mol% and the content of the unit derived from the monomer represented by the general formula [2] is [B] mol%, the formula [A] / ([A] + [B] ) ≧ 0.3 is preferable. Further, the molecular weight of the cationic polymer is preferably 5 deciliter / g or more, as a value measured under the conditions of a temperature of 30 ° C. and a 0.1N-NaNO ₃ aqueous solution, in terms of an intrinsic viscosity which is an index thereof. . In the composition of the present invention, the cationic polymer needs to be contained in an amount of 5% by weight or more. If this amount is less than 5% by weight, the concentration is too low and the transportation cost is high, which is disadvantageous in terms of economy and has no merit. Regarding the upper limit of the content,
There is no particular limitation as long as the polymer does not become an insoluble substance and the viscosity of the aqueous solution composition at a temperature of 25 ° C. is 100,000 centipoise or less. Examples of the inorganic salt contained in the composition of the present invention include sodium chloride, potassium chloride, calcium chloride, alkali metal salts such as magnesium chloride and alkaline earth metal salts, ammonium sulfate, ammonium salts such as ammonium carbonate, and the like. These may be used alone or in combination of two or more. Regarding the content of the inorganic salt, the necessary amount of the inorganic salt varies depending on the concentration of the cationic polymer, the content of the structural unit represented by the general formula [1] in the polymer, etc. The amount may be such that it does not precipitate and the viscosity of the aqueous solution composition at a temperature of 25 ° C. is 100,000 centipoise or less.

The viscosity of the aqueous solution composition of the present invention has a temperature of 25.
It must be 100,000 centipoise or less at 0 ° C. Generally, the polymer is used by dissolving and diluting it to about 0.1 to 1.0% by weight, but when the aqueous solution composition of the high concentration polymer is transferred to the dissolution tank by a pump, it is transferred when the viscosity exceeds 100,000 centipoise. Will be difficult. The method for preparing the high-concentration aqueous solution composition of the cationic polymer of the present invention is not particularly limited, but the following method can be used, for example. That is, (1) the polymer is produced by a general method such as solution polymerization or suspension polymerization to obtain a powder polymer, which is then dissolved in a predetermined salt aqueous solution. (2) Polymerize in a predetermined amount of salt aqueous solution to obtain the desired aqueous solution composition as it is. (3) Dilute the highly concentrated gel-like substance polymerized in a predetermined amount of salt aqueous solution with water or a salt aqueous solution, Dissolve,
(4) Aqueous solution polymerization is performed, and the polymerized high-concentration gel material is diluted with an aqueous salt solution and dissolved. Applications of the high-concentration aqueous solution composition of the cationic polymer of the present invention include, in general, coagulants for wastewater treatment, sludge dewatering agents, and additives in papermaking processes (water drainage improving agents, yield improving agents) and the like. It is not particularly limited to these.

[0018]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. Production Example 1 A predetermined amount of dimethylaminoethyl acrylate methyl chloride quaternary product, dimethylaminoethyl acrylate benzyl chloride quaternary product and acrylamide were dissolved in pure water, and 2.
A 0 mol / liter monomer aqueous solution was prepared. Then, the aqueous solution was transferred to a four-neck separable flask,
After bubbling with nitrogen gas for 30 minutes, 5.0 × 10 ⁻⁴ mol / l of 2,2′-azobis (2-amidinopropane) dihydrochloride dissolved in a small amount of pure water was added and heated to 40 ° C. For 8 hours. The obtained high-concentration polymer gel was pulverized in a large amount of acetone, filtered, and then dried by vacuum drying to obtain a powder polymer. Then, the intrinsic viscosity, which is an index of molecular weight, was measured at 30 ° C. in a 0.1N-NaNO ₃ aqueous solution. The results are shown in Table 1. Production Examples 2 to 5 and Comparative Production Examples 1 to 3 By the same method as in Production Example 1, a polymer having the composition shown in Table 1 was produced, and its intrinsic viscosity was determined. The results are shown in Table 1.

[0019]

[Table 1]

DAA (CH ₃ Cl): Dimethylaminoethyl acrylate quaternary methyl chloride DAA (BzCl): Benzyl chloride quaternary dimethylaminoethyl acrylate DAM (CH ₃ Cl): Dimethylaminoethyl methacrylate methyl quaternary Grade DAM (BzCl): Benzyl chloride quaternary of dimethylaminoethyl methacrylate AAm: Acrylamide Examples 1 to 5, Comparative Examples 1 to 4 Various powdered polymers shown in Table 2 were added while stirring a salt solution having a predetermined concentration. In addition, after stirring for 1 hour, the mixture was left for 2 days to prepare an aqueous solution composition, and the viscosity at 25 ° C. was determined. The results are shown in Table 2.

[0021]

[Table 2]

As can be seen from Table 2, in the case of the conventional polymer (comparative example), the viscosity is 100,000 centipoises or more even when salt is added, and in order to reduce the viscosity to 100,000 centipoises or less, the polymer concentration is 5% by weight. You can't go above%.

[0023]

The highly concentrated aqueous solution composition of the cationic polymer of the present invention has the following effects. (1) Since it is a liquid product, it can be automated, rationalize the melting work, and shorten the melting time. (2) A high-concentration aqueous solution that cannot be achieved by conventional polymers can be obtained, which is economically advantageous. (3) The problems of moisture absorption and dust, which are defects of powder products, are solved. (4) Since it is not a suspended dispersion polymer, there is no problem of product stability such as sedimentation separation. (5) Since no solvent is used, the working environment is greatly improved.

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Claims (1)

[Claims] 1. A general formula: (In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is a methyl group or an ethyl group, R ³ is a benzyl group, X ⁻ is an anion, and A is −.
NH- or -O-, B is A cationic polymer containing 10 mol% or more of a structural unit represented by the formula), an inorganic salt and water, and containing 5 wt% or more of the cationic polymer,
A high-concentration aqueous solution composition of a cationic polymer, which has a solution viscosity at a temperature of 25 ° C. of 100,000 centipoise or less.