JPH028207A - Aqueous solution of polymer - Google Patents

Abstract

PURPOSE:To obtain a homogeneous aqueous solution of a polymer free from partial gel by adding a specific reactive surfactant to an aqueous solution of a specific polymerizable monomer such as alpha,beta-unsaturated carboxylic acid amide and cationic monomer and subjecting the monomer to radical polymerization. CONSTITUTION:The objective aqueous solution of polymer suitable as a paper strengthening agent can be produced by mixing (A) a 5-35wt.% aqueous solution of polymerizable monomers composed of (i) preferably 99.79-59.0mol% of an alpha,beta-unsaturated carboxylic acid amide of formula I (R1, R1' and R1'' are H or methyl), (ii) preferably 0.1-20.0mol% of a cationic monomer of formula II (R2 and R2' are methyl, etc.; A is -COO-, etc.; B is -CH2CH2-, etc.), (iii) preferably 0.1-20.0mol% of an alpha,beta-unsaturated (di)carboxylic acid monomer of formula III (R3 is H, methyl, etc.; R4 is H or carboxyl; M<+> is proton, etc.), and (iv) preferably 0.01-1.0mol% of a crosslinkable monomer having two or more polymerizable double bonds with (B) preferably 0.01-1.0wt.% (based on the polymerizing monomers) of a reactive surfactant radically polymerizable with said polymerizable monomers and carrying out the radical polymerization of the above monomer components.

Description

[Detailed description of the invention] Industrial applications: The present invention relates to aqueous polymer solutions.

Furthermore, the aqueous polymer solution produced according to the present invention has an excellent paper strength enhancing effect.

Conventional technology and its issues: In recent years, the paper industry has become increasingly dependent on waste paper due to raw material conditions, and on the other hand, due to social demands for environmental protection, there has been a trend toward closed treatment of industrial wastewater in response to wastewater regulations.

Furthermore, due to factors such as increased papermaking speeds, there is a strong desire to improve the one-pass yield of papermaking additives.

Conventionally, acrylamide-based polymers have been the mainstream paper strength enhancer. In order to improve the one-pass yield of this acrylamide-based polymer, a method of increasing the molecular weight of the polymer is implemented. However, if the molecular weight is simply increased, the cohesive force becomes stronger, which interferes with paper formation and reduces paper strength.

On the other hand, there is a technique in which a crosslinking agent is added to the polymerization system of an acrylamide monomer to introduce a crosslinked structure into the polymer chain, thereby improving one-pass yield through entanglement with pulp fibers. A problem with this crosslinking technology is that the polymer aqueous solution exhibits viscoelastic behavior, and during production in a stirred polymerization reaction tank, a phenomenon of wrapping around the stirring shaft due to the Weissenberg effect occurs.

If this wrapping phenomenon occurs during the polymerization reaction, it becomes difficult to stir the polymerization tank after that, the temperature rises due to the local accumulation of polymerization heat, and the polymerization rate increases, causing partial gel ovalization. proceed.

An object of the present invention is to suppress the wrapping phenomenon around the stirring shaft during the polymerization reaction, prevent the above-mentioned local gelation, and provide a uniform aqueous polymer solution in the production of a water-soluble acrylamide polymer having a crosslinked structure. shall be.

Means for achieving the object: In order to achieve this object, the present inventors conducted various studies and found that an α,β-unsaturated carboxylic acid amide such as acrylamide represented by the general formula (I[I) Mainly, this and a specific cationic monomer represented by general formula (I) and/or α, β-unsaturated (
In the monomer composition consisting of di)carboxylic acid, for example, by adding a small amount of a reactive surfactant to a polymerization reaction recipe using a crosslinking monomer such as N,J'J-methylenebisacrylamide, the above-mentioned aqueous polymer solution can be It was discovered that the phenomenon of winding around the stirring shaft is suppressed, and at the same time, the resulting aqueous polymer solution has uniform properties that do not contain any partial gels, leading to the completion of the present invention.

The polymerization system targeted by the production method according to the present invention has the general formula (I
) and the general formula (n), (II[
) and at least one of the polymerizable monomers represented by
Moreover, it is a 5 to 35% by weight aqueous monomer solution containing a compound for introducing a crosslinked structure into the polymer chain, such as a crosslinkable monomer.

R+ /R'' CR2= C-C〇-N (I)\K /R' CR2= C-A B -N
(II)\R= Ra (I[I) CH=C-COO-Mf (In the formula, R+, R″1, and R are hydrogen atoms or methyl groups; R
2. Flea is a methyl group or an ethyl group; R3 is a hydrogen atom, a methyl group, or a carboxymethyl group; R4 is a hydrogen atom or a capoxyl group; A is -COO-
group or -NH-CO- group B is -C)h CHt-, -
Any one group of CH2C82CH2--CH2CHO11CR2-; M+ represents a cation of any one of protons, alkali metals, and ammonium ions) The compound represented by general formula (I) forms a hydrogen bond with cellulose fibers. , is the main factor that produces the paper strength enhancement effect.

Examples of compounds represented by formula (I) include acrylamide, methacrylamide, and N,N-dimethylacrylamide.

Polymers containing the polymerizable monomer represented by general formula (II) exhibit self-fixing properties for cellulose during papermaking, and the sulfate band required in the case of anionic polyacrylamide such as acrylamide-acrylic acid copolymer. No need to use fixatives such as

Further, if the content in the polymer is less than 1 mol %, the above effect will hardly be exhibited, and if it exceeds 20 mol %, it is not preferable from an economic standpoint.

Examples of the chemical compounds represented by the general formula (It) include dimethylamine ethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl acrylate, dimethylamine-2-hydroxypropyl acrylate, dimethylamine propyl ( meth)acrylamide, diethylaminopropyl(meth)acrylamide and their salts with inorganic and organic acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, or quaternary ammonium added with methyl chloride, ethyl chloride, methyl bromide, benzyl chloride, etc. It is a monomer containing salt.

By containing the polymerizable monomer represented by general formula (III), the paper strength enhancing effect can be further increased. If its content in the polymer is less than 1 mol %, it has almost no effect, and if it exceeds 15 mol %, the repulsion with the negative charge of cellulose increases, and the fixing ability of the polymer decreases.

Examples of the compound represented by the general formula (III) are acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, and their sodium salts, potassium salts, and ammonium salts.

Examples of crosslinkable monomers used to introduce a crosslinked structure into polymers containing general formulas (I), (II), and <II) include N,N-methylenebis(meth)acrylamide;
Examples include crosslinking monomers such as glycidyl (meth)acrylate, N-methylol acrylamide, and polyethylene glycol di(meth)acrylate.

As a reactive surfactant, a compound that has a polymerizable double bond in its molecule and has both a hydrophilic group and a lipophilic group can be used as either nonionic or anionic. 3-sulfoacryl (meth)acrylate shown in Japanese Patent Application Laid-open No. 45-10
Examples thereof include the sodium salt of allyl alkyl sulfone succinate shown in Japanese Patent Publication No. 2940, and phosphoric acid ester compounds shown in JP-A-57-198735.

These reactive surfactants include, for example, alkyl sulfone succinates are commercially available from Sanyo Kasei (2), and phosphate ester-based reactive surfactants are commercially available from Dai-ichi Kogyo Seiyaku (2).

The amount of the reactive surfactant used in the present invention is usually 0.01 to 10% by weight, preferably 0.05 to 10% by weight, based on the monomer.
If the amount of the 6-reactive surfactant used is small (0.5% by weight), the above-mentioned effects will not be exhibited, and even if the amount used is large, the effect will remain the same and it will not be economical.

As the polymerization catalyst used in the present invention, radical catalysts such as known azo catalysts, redox catalysts, or a combination thereof can be used. As an azo catalyst, 2
．． 2'-azobis(2-amidinopropane) hydrochloride, 4
, 4'azobis-4-cyatubaleic acid and the like. Examples of redox catalysts include combinations of peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide and reducing compounds such as sodium sulfite, acidic sodium sulfite, and organic amines.

Example 1 11.8 g of dimethylamine ethyl methacrylate (hereinafter referred to as DM), 5.4 g of acrylic acid, and 124.2 g of acrylamide were placed in a four-bottle flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas introduction tube. ,N,
0.33 g of N-methylenebisacrylamide (hereinafter referred to as MBAm) and 523 g of water were charged, and the solution was purified with sulfuric acid.
To a monomer aqueous solution whose H was adjusted to 4.0, 10 g of alis alkyl sulfone succinate (trade name: Reminol JS-2, manufactured by Sanyo Kasei) was added as a reactive surfactant. The temperature was raised to 60°C under the introduction of nitrogen gas, and 1.1 g of ammonium persulfate and 0.5 g of sodium sulfite were added. The viscosity of the aqueous solution increased as the polymerization reaction progressed, but no wrapping around the stirring shaft was observed. First, the fluidity of the polymerization system was good. The generated polymer aqueous solution is 1
At 5% by weight, the viscosity was 4500 cps (measured at 2''°C with a Type B viscometer).

Example 2 Polymerization was carried out in the same manner as in Example 1, except that the amount of reactive surfactant JS-2 added was 0.5 g. Although some winding phenomenon was observed, the fluidity of the polymerization system was almost good.

The viscosity of the produced polymer aqueous solution is 7000 cps (25
°C).

Example 3 Phosphate ester-based reactive surfactant (Daiichi Kogyo Seiyaku ■
Product name: New Frontier A-229E) 1.0
Polymerization was carried out in the same manner as in Example 1 except that g was used. No wrapping phenomenon around the stirring shaft was observed, and the fluidity of the polymerization system was good. The viscosity of the produced polymer aqueous solution is 5000c.
(25°C).

Comparative Example 1 Polymerization was carried out under the same conditions as in Example 1 without adding any reactive surfactant. Severe wrapping around the stirring shaft was observed,
Eventually, the entire polymerization system became gel-like.

Comparative Example 2 Polymerization was carried out under the conditions of Example 1, using 2.0 g of a polyoxyethylene alkyl sulfosuccinate surfactant having a similar structure in place of the reactive surfactant JS-2. A phenomenon of wrapping around the stirring shaft was observed. The resulting polymer aqueous solution is 15% by weight and has a viscosity of 30,000 cps.
(25°C).

Comparative Example 3 In a fourth flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas introduction tube, 8 g of DM, 54 g of acrylic acid, 124.2 g of acrylamide, and M B
11 g of A mO and 523 g of water were charged, and the pt-t was adjusted to 4.0 with sulfuric acid. 60 under nitrogen gas introduction
The temperature was raised to 0.degree. C., and 0.6 g of ammonium persulfate and 0.2 g of sodium sulfite were added. The resulting polymer aqueous solution was 15% by weight and had a viscosity of 6000 cps (25°C).

Table 1 shows the test results of the water-soluble polymers prepared in the Examples and Comparative Examples as paper strength enhancers.

However, as the test pulp, paper mill pulp (NL) was used as the test pulp.
JKP), the paper strength enhancer was added in an amount of 0.3%, 0.6.09% based on dry pulp, and the basis weight was 100%.
Paper was made at a pH of 6.0 to 10 so that the paper density was 0±2.0 g/rd, and after dehydration, it was dried at 105 to 110° C. for 3 minutes. The thus obtained paper was conditioned at 20° C. and relative humidity of 65% for 24 hours, and then its specific bursting strength was measured according to the JIS method.

Table 16 Paper Strength Test Results As is clear from the test results, the paper strength agent produced according to the present invention exhibits excellent paper strength effects. This is because the paper strength enhancer shown in the Examples has an increased physical fixing ability for cellulose due to the crosslinked structure in the polymer chain, and as a result, the yield has improved.

Patented Emperor Yoshida Bunkiden Case 0 display Patent application 1986-1'40 Name of G3 invention person who makes corrections Relationship with the incident Residence (residence) Full name (name) Management Man polymer aqueous solution applicant 671-4 Mizuashi, Noguchi-cho, Kakogawa-shi, Hyogo Prefecture Harima Chemical Industry Co., Ltd. date Showa Year Month Day (voluntary) 1. The scope of the patent claims will be amended as follows.

[1 A compound represented by the following general formula (I) and a compound represented by the general formula (n
), (III) and a 5 to 35% aqueous solution of a polymerizable heptamer consisting of a crosslinkable monomer having two or more polymerizable double bonds in the molecule; An aqueous polymer solution characterized in that monomer or polymer thereof is radically polymerized by adding a reactive surfactant capable of radical polymerization.

R+ /R1 CHt=C-Co-N (I
＞/R2 CH! = C-A-B-N (II> \m a (III) CH=C-COO-M" (in the formula, R+, R'+, pressure is a hydrogen atom or a methyl group: R
2. Field is a methyl group or an ethyl group; R3 is a hydrogen atom, a methyl group or a carboxymethyl group; R4 is a hydrogen atom or a capoxyl group; A is -C00-
group or -NH-CO- group; B is -CHICHs--C
Ht C)h Any one group of CHt-, -CHtCHOHCHt-; M+ represents any one cation of a proton, an alkali metal ion, or an ammonium ion.) 2 The polymerizable monomer has (I) 99. 79-59.0
mol%, (II) is 0.1 to 20.0 mol%, (III
) is 0.1 to 20 mol %, and 0.01 to 1.0 mol % of crosslinkable heptamer having two or more polymerizable double bonds in the molecule
The aqueous polymer solution according to claim 1, wherein the aqueous polymer solution contains a total amount of 100 mol% within the range of .

3. The aqueous polymer solution according to claim 1, wherein the amount of the tri-reactive surfactant added is 0.01 to 1.0% by weight based on the total amount of polymerizable monomers.

4. A paper-making additive containing the aqueous polymer solution according to any one of claims 1 to 3 as a main component," 2. Detailed description of the invention, page 5, line 3 [-maximum (III)] ” is replaced with “
- At maximum (I)”, page 5, line 5, “- at maximum (I)” is changed to “- at maximum (II)”, page 5, lines 6 to 7 Correct the text ``J'' with ``-maximum (U)'' to ``-maximum (III)''.

Claims (1)

[Scope of Claims] 1. A compound represented by the following general formula (I) and a compound represented by the general formula (I);
II), (III) and a crosslinkable monomer having two or more polymerizable double bonds in the molecule. or a polymer aqueous solution obtained by radical polymerization by adding a polymer thereof and a reactive surfactant capable of radical polymerization with the polymer. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) (In the formula, R_1, R'_1, R" _1 is a hydrogen atom or a methyl group; R_2, R'_2 is a methyl group or an ethyl group;
R_3 is a hydrogen atom, a methyl group, or a carboxymethyl group; R_4 is a hydrogen atom or a carboxyl group; A is a -COO- group or a -NH-CO- group; B
is -CH_2CH_2-, -CH_2CH_2CH_2
-, -CH_2CHOHCH_2-; M^+ represents any one cation of a proton, an alkali metal ion, or an ammonium ion. ) 2 The polymerizable monomer has (I) of 99.79 to 59
．． 0 mol%, (II) 0.1 to 20.0 mol%, (III
) is 0.1 to 20 mol%, and the crosslinkable monomer having two or more polymerizable double bonds in the molecule is 0.01 to 1.0 mol%.
The aqueous polymer solution according to claim 1, wherein the aqueous polymer solution contains a total amount of 100 mol% within the range of . 3. The aqueous polymer solution according to claim 1 or 2, wherein the amount of the reactive surfactant added is 0.01 to 1.0% by weight based on the total amount of polymerizable monomers. 4. A papermaking additive comprising the aqueous polymer solution according to any one of claims 1 to 3 as a main component.