JPS6215251A - Production of liquid dispersion of water-soluble cationic polymer - Google Patents

Abstract

PURPOSE:To produce the titled dispersion having high fluidity and handleability, by dispersing particles of cationic water-soluble polymer in an aqueouss salt solution which is a non-solvent of the polymer, in the presence of a polymer soluble in said salt solution. CONSTITUTION:The objective dispersion can be produced by dispersing (A) particles of a polymer produced by the copolymerization of (a) a cationic monomer of formula I (R1 is H or CH3; R2 and R3 are 1-3C alkyl; A is O or NH; B is 2-4C alkylene or hydroxypropylene; X<-> is anionic counter ion) and (b) other monomer copolymerizable therewith at a molar ratio of 100:0-5:95 in (B) an aqueous salt solution which is a non-solvent of the component A (e.g. aqueous solution of ammonium sulfate) at a concentration of >=10wt%, and adding (C) >=0.1wt% (based on the component B) dispersing agent consisting of a polymer soluble in the component B, preferably a polymer produced by copolymerizing (c) a cationic monomer of formula II (R2 and R3 and 1-2C alkyl; R4 is H or 1-2C alkyl) and (d) acrylamide at a molar ratio of 100:0-20:80.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is directed to the production of a dispersion of a cationic water-soluble polymer, which is used as a flocculant for wastewater treatment, a dehydrating agent, and a papermaking agent used in the papermaking process. It is about the method.

[Conventional technology]

Conventionally, cationic water-soluble polymers that have been used as flocculants and dehydrating agents for wastewater treatment, or as agents for paper manufacturing are produced after aqueous polymerization (2) aqueous crystals diluted with water to a low concentration, and after aqueous polymerization ( Two-dried powder product (Special Publication Act, 1984-4)
0842 Water-in-oil emulsion! Iy product (Unexamined Japanese Patent Publication No. 1983-
102388), and a pearl-like powder obtained by suspension polymerization in a hydrophobic solvent (Japanese Unexamined Patent Publication No. 54-69196) are commercially available.

[Problem that the invention seeks to solve]

Commercially available water bath liquid crystals with low concentrations of 10% or less require high transportation costs, and suspension polymerization in hydrophobic solvents uses flammable substances such as toluene and cyclohexane.
Manufacturing equipment 1: It has drawbacks such as requiring a large amount of cost. Powdered products also have drawbacks such as they tend to become lumpy when dissolved in water, take a long time to dissolve, and easily generate dust. Although water-in-oil emulsions have good fluidity and a fast dissolution rate, they have the disadvantage of being flammable and wasteful of valuable organic solvents.

[Means for solving problems]

The present inventors have conducted extensive research aimed at overcoming these drawbacks and producing a dispersion of a cationic water-soluble polymer that has good fluidity and is easy to handle, and as a result, the present invention has been achieved.

That is, the present invention comprises one or more cationic monomers represented by the following formula (I) and another monomer copolymerizable therewith in a molar ratio of 100:0 to 5:95. Particles of a polymerized product copolymerized within a range of 100 to 100% are dispersed in an aqueous salt solution that does not dissolve the polymerized product. The present invention relates to a method for producing a dispersion of a cationic water-soluble polymer.

Ru Hatake (in the formula, is H or CH, nyl, 几9 is carbon number 1-3
Alkyl group: Human is oxygen atom or NH: B has 2 carbon atoms
~4 alkylene group or hydroxypropylene group;
) t anionic counterion. ) Typical cationic monomers represented by this formula CI) include dimethylamine ethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminohydroxypropyl (meth)acrylate, and dimethylaminopropyl (meth)acrylate. ) acrylamide and benzyl chloride (
:Although more quaternized monomers may be mentioned, any monomer satisfying the formula (I) can be used.

Further, typical examples of monomers copolymerizable with the cationic monomer of formula (I) include (meth)acrylamide, N, N-
Dimethyl (meth)acrylamide, dimethylaminoethyl (meth)acrylate and its quaternized products with methyl chloride, dimethyl sulfate, etc., dimethylaminopropyl (
Examples include meth)acrylamide and those obtained by quaternizing this with methyl chloride, dimethyl sulfate, etc., but monomers other than these are not particularly limited as long as the copolymer is water-soluble.

Hydrophobic monomers such as styrene and methyl methacrylate can also be used in amounts that will maintain the water bathability of the copolymer. It is also possible to copolymerize two or more types of copolymerizable monomers.

In the present invention (=), both the homopolymer of the cationic monomer of formula (I) and the copolymer using up to 95 mol of other copolymerizable monomers have good fluidity. A dispersion can be obtained.

Regarding the aqueous salt solution, which is the dispersion medium used in the present invention, it is a condition that the particles of the polymerization product are not dissolved. Typical salts include sodium sulfate, ammonium sulfate, magnesium sulfate, aluminum sulfate, sodium chloride, sodium dihydrogen phosphate, ammonium hydrogen phosphate, dipotassium hydrogen phosphate, or two or more of these salts. Examples include mixtures of Salts other than these are within the scope of the present invention as long as they do not dissolve the polymerization product. The salt concentration of the aqueous salt solution is determined by the formula (I
) The molar ratio of the cationic monomers and the salt I used: Although not particularly limited, a range of 15% by weight or more up to the limit of solubility is generally preferred.

The polymer as a dispersant added to the salt aqueous solution is not particularly limited as long as it dissolves in the salt aqueous solution, but since the polymerization product is cationic, nonionic polymers or cationic polymers are preferred.

Particularly preferred is one or more cationic monomers represented by the following formula (I[) described in claim 2 and acrylamide in a molar ratio of 100:
It is a polymer copolymerized in the range of 20:80.

R1 (in the formula, R, is H or CH,; H,,, & has 1 carbon number
-2 alkyl group: 几4I/'iH or carbon number 1-2
alkyl group; A is an oxygen atom or N) 1: B is an alkylene group having 2 to 4 carbon atoms or a hydroxypropylene group;
X″″ is an anionic counterion. ) Typical cationic monomers of formula (II) include dimethylaminoethyl (meth)acrylate, dimethylaminepropyl (meth)acrylamide, dimethylaminohydroxypropyl (meth)acrylate, and methyl chloride,
Examples include those quaternized with dimethyl sulfate, but the formula (I
Any monomer that satisfies [) can be used.

The higher the molecular weight of the polymer used as this dispersant, the better.
The reduced viscosity of the 0.1 cIb polymer solution (in IN saline) is preferably 3 or more, preferably 5 or more. The i of the dispersant varies depending on the molecular weight of the polymer, but it is 0 for a salt aqueous solution.
．． It is preferably 1% by weight or more.

Moreover, t of the polymerization product containing the cationic monomer of formula (I) as a component is preferably 10 weight or more when sealed with a salt aqueous solution, and if it is less than that, there is no superiority over the aqueous solution crystal.

Although the method for preparing the particles of the polymerization product to be dispersed in the salt aqueous solution is not limited to special ships, it is preferable to use particles with a particle size of 3 mm or less in terms of dispersibility. The particles can be obtained by pulverizing a dried polymer product, wet pulverizing a hydrous gel, or granulating it with a meat chopper or the like.

The method for preparing the dispersion liquid is not particularly limited, and the particles may be dispersed in an aqueous salt solution and then a dispersant may be mixed therein, or the particles may be dispersed in an aqueous salt solution in which the dispersant is dissolved. Alternatively, a dispersant may be mixed in after the hydrous gel is finely dispersed by applying a homomixer (= = homomixer) in a salt aqueous solution.

[For production]

The aqueous salt solution in the present invention is used to prevent the polymerization product containing formula (I) from being dissolved, and also serves as a dispersion medium to maintain fluidity. C: Yes, the dispersant is used to obtain a stable dispersion through electrical repulsion and thickening.

The cationic monomer of formula (1) has a strongly hydrophobic benzyl group bonded to the amino group, which makes it difficult to dissolve in salt aqueous solutions despite being a cationic water-soluble polymer. .

〔Example〕

Next, the present invention will be explained in detail based on two examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 32.9 f (65 mol. ty2 water change 100
f + two-bath dissolution, heating to 40° C. and purging with nitrogen. Next, 0.02 f of ammonium persulfate and 0.02 t of sodium bisulfite were added and polymerized to obtain a gel-like hydrated polymer.

This is referred to as polymer (A).

Example 2 Polymer (A) was cut into thin slices with a knife, 105
Dry at ℃ and then grind with a coffee mill to obtain particles with a particle size of
■The following powder was obtained. 20t of this powder was dispersed in 80f of an aqueous solution of ammonium 25 sulfate, and then a homopolymer of methacryloyloxyethyltrimethylammonium chloride (0.1%, reduced viscosity in IN salt solution of 5.5%)
2) was added and dissolved to prepare a dispersion.

Example 3゜Polymer (A) 401 was placed in a homomixer, and 209 separately prepared ammonium sulfate and 0.3F acryloyl □A copolymer of oxyethyltrimethylammonium chloride and acrylamide (molar ratio was 50:5)
A solution of powder having a reduced viscosity of 6.0) dissolved in water 402 was added and vigorously stirred. While the polymer (A) is being salted out,
A dispersion liquid was obtained with particles of 1 or less size.

Example 4 Acrylamide 30.0f (70 mol%), dimethylaminoethyl methacrylate sulfate 12.4f (10 molty), acryloyloxyethyldimethylammonium chloride 32.6F (20 molty) were mixed with 75% of ion-exchanged water.
The mixture was dissolved in t and heated to 50°C and replaced with nitrogen. Next: 0.03 f of 22,2'-azobis(2-amidinopropane) hydrochloride was added to initiate polymerization to obtain a gel-like hydrated polymer. This is referred to as polymer (13).

Example 5 Polymer (B) was passed through a meat chiller and granulated to a particle size of 1 to 2 m. 4Of of this was added to 60f of 40 ammonium thiosulfate H solution and stirred. After dispersing, 0.
A powder of homopolymer (reduced viscosity 5.5) of acryloyloxyethyltrimethylammonium chloride No. 52 was added and dissolved to prepare a dispersion.

〔Effect of the invention〕

The samples of Examples 2 and 3.5 were left at room temperature for one month without losing their fluidity. On the other hand, those to which no dispersant was added lost fluidity after one day.

Claims (1)

[Claims] 1. One or more cationic monomers represented by the following formula (I) and another monomer copolymerizable therewith in a molar ratio of 100:0 to 5. : When dispersing particles of a polymerized product copolymerized in the range of 95 in an aqueous salt solution that does not dissolve the polymerized product, a cation characterized by adding a polymer soluble in the aqueous salt solution as a dispersant. A method for producing a dispersion of a water-soluble polymer. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R_1 is H or CH_3; R_2 and R_3 are alkyl groups with 1 to 3 carbon atoms; A is an oxygen atom or NH; B
is an alkylene group or hydroxypropylene group having 2 to 4 carbon atoms; X^- is an anionic counterion. ) 2. The polymer added as a dispersant and soluble in the salt aqueous solution has the formula (
The molar ratio of one or more of the cationic monomers shown in II) and acrylamide is 100:0 to 20:
80, and the amount thereof is 0.1% by weight or more based on the aqueous salt solution. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) (In the formula, R_1 is H or CH_3; R_2 and R_3 are alkyl groups with 1 to 2 carbon atoms; R_4 is H or
2 alkyl group; A is an oxygen atom or NH; B is an alkylene group having 2 to 4 carbon atoms or a hydroxypropylene group;
X^- is an anionic ion. )