JP4579051B2 - Polymer flocculant and method for producing the same - Google Patents

Description

  The present invention relates to an ultra-high molecular weight polymer flocculant having superior spinnability, solubility and flocculation performance used for various industrial wastewater, sludge treatment and sewage sludge treatment, and a method for producing the same.

  Conventionally, polymer flocculants have been industrially produced and marketed according to their respective characteristics, from the product form to powder, emulsion (latex), aqueous solution or suspension. Each production method is mainly bulk polymerization, reverse phase emulsion polymerization, aqueous solution polymerization and suspension polymerization, and production facilities are also different. In addition, polymer flocculants generally have a high molecular weight except for some uses, and polymers (polymers or copolymers) polymerized or copolymerized in a more linear form also have an added amount. The amount of flocs obtained as a coagulation operation is increased and the performance is excellent.

  On the other hand, when the water-soluble monomer (monomer) is polymerized or copolymerized in an aqueous system, it is industrially advantageous to polymerize or copolymerize the polymer at a high concentration even if it is a little. In other words, the higher the concentration, the higher the charging efficiency overall, and if the product form is a powder product, the drying time in the drying process is shortened, and the emulsion product (latex polymer), aqueous solution If it is a product or a suspension product, the storage space for the product can be reduced and the transportation cost can be reduced.

  However, when the monomer concentration in the aqueous phase is increased, it is difficult to control the polymerization rate during polymerization (or copolymerization), and the temperature of the polymer is likely to increase during the polymerization operation. Internal or intermolecular crosslinking is likely to occur, and the resulting polymer (polymer or copolymer) may be partially oxidatively decomposed, become a branched structure polymer, or become a three-dimensional crosslinked polymer. Degraded performance. Therefore, conventionally, the polymerization operation is carried out while suppressing the monomer concentration as much as possible, but sufficient results have not been obtained.

  In order to solve such problems, various proposals have been made to date. For example, the effect of preventing deterioration of a water-soluble polymer by adding ethylenediaminetetraacetate, thiomalic acid, thiosalicylic acid or the like to the polymerization reaction system. (Patent Documents 1 and 2), those that expect a deterioration prevention (crosslinking prevention) effect by adding a polyamine salt or a polyamine quaternized product to a water-soluble polymer system (for example, Patent Document 3), or There is a method of polymerizing in the presence of an ascorbic acid derivative to obtain a high molecular weight polymer having good water solubility (for example, Patent Document 4).

  In addition, using known urea, thiourea, hydroquinone, guanidine salt, etc. as a crosslinking inhibitor, devising a polymerization catalyst to prevent thermal degradation of the polymer produced during polymerization, molecular weight distribution using a known chain transfer agent Some have tried to obtain a water-soluble high molecular weight polymer by averaging (preventing inadequate crosslinking during polymerization) or by devising production equipment and production processes as proposed in Patent Document 5. .

Japanese Patent Laid-Open No. 58-40306 JP 58-61105 A Japanese Patent Publication No.54-32657 JP-A-5-247136 JP 62-235305 A

  However, although these proposals have a temporary effect, they are not always sufficient. These may be added to the polymerization system to solve the problems, such as deterioration inhibitors, crosslinking inhibitors, polymerization processes, or control of molecular weight distribution by known chain transfer agents. Although it is a devise of the polymerization catalyst, there are some effects, but it is not always sufficient.

  The inventor of the present invention is based on the idea that the above-mentioned crosslinking inhibitor is completely reversed from the idea, and that the crosslinking polymer is used to prevent inadvertent crosslinking of the resulting polymer in terms of molecular structure to obtain an ultrahigh molecular weight water-soluble polymer. Further, an ultrahigh molecular weight polymer flocculant having excellent spinnability obtained by polymerizing or copolymerizing various monomers in the presence of a crosslinking agent was proposed in Japanese Patent Application No. 2003-199750. In order to provide a polymer flocculant having an even better agglomeration performance, and based on the effects shown in Japanese Patent Application No. 2003-199750, it is completely new for the purpose of further improving the agglomeration performance characteristics and agglomeration performance. It was created based on the idea.

  If the polymer flocculant has few cross-linking points when the flocculant is formed, the molecular polymer spreads in the aqueous solution, and the backbone polymers are bonded to each other by partial chemical cross-linking while maintaining spinnability. Is formed. On the other hand, if there are too many crosslinking points, the molecules will be inhibited from spreading in water and will be shrunk, making them extremely insoluble. In the present invention, what is important for the aggregation performance is that the trunk polymer portion is as long as possible with a high molecular weight as much as possible, and the crosslinking points have as few crosslinking points as possible.

  In addition, experiments based on the idea that partial chemical cross-linking can be intentionally caused to block uncontrollable uncontrollable cross-linking (natural cross-linking) in the middle of other trunks (physically and sterically hindering binding). Proved this.

  That is, in the polymer flocculant, the aggregation performance can be improved by the balance between the length of the trunk polymer, the number of crosslinking sites, and the number of crosslinking points.

The present invention is a form in which a water-soluble polymer having a crosslinking point in a dissolved state is present in a polymerization system , and the polymer having the crosslinking point is incorporated into a produced polymer by copolymerizing the monomers described in the claims . Finally, the desired polymer is produced, so that the molecular weight becomes higher and the aggregation performance is improved.

  In any case, the method of the present invention makes it possible to control the position and number of crosslinking points, thereby making it possible to create polymer flocculants of various properties.

  Although it takes more time to fully elucidate the effect of preventing spontaneous crosslinking during polymerization, which is one of the effects of the present invention, the following may be considered as an estimate. That is, the epoxy group of the cross-linking agent in the polymerization system is mainly bonded to some of the carboxyl groups in the monomer or polymer or other functional groups that can be cross-linking points, and the polymer side chain is made bulky and stable. It is considered that three-dimensional crosslinking is three-dimensionally prevented.

The polymer flocculant according to the present invention is a water-soluble copolymer having a crosslinking point and a copolymer of acrylic acid and acrylamide and dimethylaminoethyl acrylate methyl chloride quaternary salt or acrylamide and dimethylaminoethyl acrylate methyl chloride quaternary salt. In the presence of a polymer and a cross-linking agent, it is composed of a copolymer obtained by copolymerizing acrylic acid, acrylamide, and each monomer of dimethylaminoethyl methacrylate methyl chloride quaternary salt or dimethylaminoethyl acrylate methyl chloride quaternary salt.

When the monomer used in the present invention is polymerized or copolymerized in the presence of a water-soluble polymer having a crosslinking point and a crosslinking agent, under a condition that a small amount of a monomer having an active group having an active hydrogen serving as a crosslinking point exists, An administrative group having active hydrogen as a crosslinking point, obtained by controlling the number and position of crosslinking points as long as the crosslinking sites in the polymer chain do not negatively affect the spinnability, solubility, and aggregation performance of the polymer. And can include a carboxyl group, an amino group, a hydroxyl group, and the like. In addition, when there are too many monomers having a responsive group, the crosslinking point increases, resulting in excessive crosslinking, and the spinnability and solubility are impaired.

  As another substance (crosslinking agent) that brings about the effect of the present invention, a substance capable of bridging a specific crosslinking point with respect to the backbone polymer chain or other desirable physically and sterically by binding to a specific crosslinking point. Any substance that can block the occurrence of natural cross-linking is possible.

  That is, any substance (crosslinking agent) capable of causing a chemical reaction with a carboxyl group, amino group, hydroxyl group or the like having an active hydrogen at the terminal may be used. For example, diepoxy compounds, cyclic epoxy compounds, di- and polyisocyanates. Examples thereof include narate compounds, di- and polymethylolphenol resins, aziridine compounds, amine compounds, and dialdehyde compounds.

  The present invention can be applied to any conventional method (known method) such as bulk polymerization, reverse phase emulsion polymerization, aqueous solution polymerization, suspension polymerization, etc. (not necessarily limited to), The product form includes powder, emulsion (latex polymer), aqueous solution, and suspension.

  EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

  In a 500 ml separable flask, 0.5 part by weight of a water-soluble polymer (composition ratio AA / AAM / DAC = 0.025 / 19.975 / 80 molar ratio), 80% acrylic acid 0.04 part by weight, 50% acrylamide 61. 56 parts by weight, 25% caustic soda 0.07 part by weight, 78% dimethylaminoethyl methacrylate methyl chloride quaternary salt 269.37 parts by weight, azo initiator 0.03 part by weight, deionized water 23.5 parts by weight, cross-linking 0.48 part by weight of an inhibitor and 0.40 part by weight of polyethylene glycol diglycidyl ether were added, the pH of the system was adjusted to 4.0 with acid and alkali, and the atmosphere was purged with nitrogen for 60 minutes with stirring. The polymer was sealed and polymerized at 38 ° C. for 24 hours, and then allowed to stand at a water bath temperature of 50 ° C. for 6 hours to prepare a bulk polymer sample. Subsequently, only the composition ratio was changed in the same manner to prepare a sample of Comparative Example 1. These samples are shown in Table A.

The polymer was added to the amount corresponding to the ratio of the water-soluble polymer compounded in the preparation of Example 1 so that the sample of Example 1 in Table A was 0.1% in the polymer content. Was dissolved in distilled water so as to be 0.1%, and the coagulation performance with respect to a 5% suspension of miso (commercial product Shinshu Ichimiso) was compared. Accurately measure 80 ml of 5% miso suspension into a colorimetric tube, add a predetermined amount of polymer, and compare the floc state after stirring 15 times (based on the “floc particle size determination table” in FIG. Flock comparison is based on the decision table).

The spinnability of the 0.1% polymer aqueous solution was better in Example 1 than in Comparative Example 1.

  In a 500 ml separable flask, 0.5 part by weight of water-soluble polymer (composition ratio AA / AAM / DAC = 10/65/25 molar ratio), 0.023 part by weight of 80% acrylic acid, 73.66 parts by weight of 50% acrylamide , 25% caustic soda 0.04 parts by weight, 78% dimethylaminoethyl methacrylate methyl chloride quaternary salt 138.04 parts by weight, azo initiator 0.02 parts by weight, deionized water 131.48 parts by weight, crosslinking inhibitor 0 .27 parts by weight and 0.54 parts by weight of polyethylene glycol diglycidyl ether were added, the pH of the system was adjusted to 4.0 with acid and alkali, and the atmosphere was purged with nitrogen for 60 minutes with stirring. The polymer was allowed to stand still for a period of time, and then the temperature of the water bath was set to 50 ° C., and the mixture was allowed to stand for 6 hours to prepare a bulk polymer sample.

  Thereafter, only the composition ratio was changed in the same manner to prepare a sample of Comparative Example 2. These samples are shown in Table C.

The polymer of Example 2 in Table C was added so that the polymer content was 0.1%, and the amount of the polymer corresponding to the proportion of the water-soluble polymer compounded in the preparation of Example 2 was added to the sample of Comparative Example 2. It was dissolved in distilled water so as to be 0.1% per minute, and the coagulation performance with respect to a 5% suspension of miso (commercial product Shinshu Ichimiso) was compared. 80 ml of 5% miso suspension was accurately weighed in a colorimetric tube, a predetermined amount of polymer was added, and the floc state was compared after stirring for 15 rotations.

The spinnability of the 0.1% polymer solution was better in Example 2 than in Comparative Example 2.

  In a 500 ml separable flask, 0.5 part by weight of water-soluble polymer (composition ratio AA / AAM / DAC = 2/18/80 molar ratio), 0.015 part by weight of 80% acrylic acid, 68.76 part by weight of 50% acrylamide 25% caustic soda 0.027 parts by weight, 78% dimethylaminoethyl methacrylate methyl chloride quaternary salt 55.22 parts by weight, azo initiator 0.01 parts by weight, deionized water 307.05 parts by weight, crosslinking inhibitor 0 .15 parts by weight and 0.54 parts by weight of polyethylene glycol diglycidyl ether were prepared, the pH of the system was adjusted to 4.0 with acid and alkali, and the atmosphere was purged with nitrogen for 60 minutes with stirring. The polymer was allowed to stand still for a period of time, and then the temperature of the water bath was set to 50 ° C., and the mixture was allowed to stand for 6 hours to prepare a bulk polymer sample.

  Thereafter, only the composition ratio was changed in the same manner to prepare a sample of Comparative Example 3. These samples are shown in Table E.

The polymer of Example 3 in Table E was added so that the polymer content was 0.1%, and the amount of the polymer corresponding to the proportion of the water-soluble polymer compounded in the preparation of Example 3 was added to the sample of Comparative Example 3. Was dissolved in distilled water so as to be 0.1%, and the agglomeration performance with respect to a 5% suspension of miso (commercial product Shinshu kazumiso) was compared. 80 ml of 5% miso suspension was accurately weighed in a colorimetric tube, a predetermined amount of polymer was added, and after stirring by rotating 15 times, the floc state was compared.

The spinnability of the 0.1% polymer solution was better in Example 3 than in Comparative Example 3.

  In a 500 ml separable flask, 0.5 part by weight of water-soluble polymer (composition ratio AAM / DAC = 20/80 molar ratio), 0.02 part by weight of 80% acrylic acid, 73.66 parts by weight of 50% acrylamide, 25% caustic soda 0.04 parts by weight, 79% dimethylaminoethyl methacrylate methyl chloride quaternary salt 127.10 parts by weight, azo initiator 0.02 parts by weight, polyethylene glycol diglycidyl ether 0.54 parts by weight, deionized water 126.38 Part by weight and 0.27 part by weight of a crosslinking inhibitor were added, the pH of the system was adjusted to 4.0 with acid and alkali, and the atmosphere was purged with nitrogen for 60 minutes with stirring. Polymerization was carried out, and then the temperature of the water bath was set to 50 ° C., and the mixture was allowed to stand for 6 hours to prepare a bulk polymer sample. These samples are shown in Table G.

The amount of the polymer corresponding to the proportion of the water-soluble polymer compounded in the preparation of Example 4 was added to the sample of Example 4 in Table G so that the sample was 0.1% in polymer content, and the polymer content was added. Was dissolved in distilled water so as to be 0.1%, and the coagulation performance with respect to a 5% suspension of miso (commercial product Shinshu Ichimiso) was compared. 80 ml of a 5% miso suspension was accurately weighed in a colorimetric tube, a predetermined amount of polymer was added, and the mixture was stirred for 15 rotations, and then the floc state was compared.

The spinnability of the 0.1% polymer solution was better in Example 4 than in Comparative Example 4.

  In a 500 ml separable flask, 0.5 part by weight of water-soluble polymer (composition ratio AAM / DAC = 20/80 molar ratio), 0.015 part by weight of 80% acrylic acid, 68.76 parts by weight of 50% acrylamide, 25% caustic soda 0 0.027 part by weight, 79% dimethylaminoethyl acrylate methyl chloride quaternary salt 50.84 part by weight, azo initiator 0.01 part by weight, polyethylene glycol diglycidyl ether 0.13 part by weight, deionized water 295.29 part by weight And 0.15 parts by weight of a crosslinking inhibitor were added, the pH of the system was adjusted to 4.0 with acid and alkali, and the atmosphere was purged with nitrogen for 60 minutes with stirring. After polymerization, the water bath temperature was set to 50 ° C. and left to stand for 6 hours to form a block polymer sample. Thereafter, only the composition ratio was changed in the same manner to prepare a sample of Comparative Example 5. These samples are shown in Table I.

The polymer of Example 5 in Table I was added so that the polymer content was 0.1%, and the amount of the polymer corresponding to the proportion of the water-soluble polymer compounded in the preparation of Example 5 was added to the sample of Comparative Example 5 The flocculation performance was compared with a 5% suspension of miso (commercial product Shinshu Ichimiso). 80 ml of 5% miso suspension was accurately weighed into a colorimetric tube, a predetermined amount of polymer was added, and the floc state was compared after stirring for 15 rotations.

The spinnability of the 0.1% polymer aqueous solution was better in Example 5 than in Comparative Example 5.

A flock particle size determination table for determining the size of a flock.

Claims (4)

In the presence of a water-soluble copolymer of acrylic acid and acrylamide and dimethylaminoethyl acrylate methyl chloride quaternary salt or a copolymer of acrylamide and dimethylaminoethyl acrylate methyl chloride quaternary salt having a crosslinking point and a crosslinking agent, A polymer flocculant comprising a copolymer obtained by copolymerizing acrylic acid, acrylamide, and dimethylaminoethyl methacrylate methyl chloride quaternary salt or dimethylaminoethyl acrylate methyl chloride quaternary salt .   The crosslinking agent is monoglycidyl ether, diglycidyl ether, polyglycidyl ether, diepoxy compound, cyclic epoxy compound, diisocyanate, polyisocyanate, dimethylol phenol resin, polymethylol phenol resin, aziridine compound, amine compound and dialdehyde compound. The polymer flocculant according to any one of claims 1 to 4. Acrylic acid, acrylamide, dimethylaminoethyl methacrylate methyl chloride quaternary salt or dimethylaminoethyl acrylate methyl chloride quaternary salt, water-soluble acrylic acid having a crosslinking point, acrylamide and dimethylaminoethyl acrylate methyl chloride quaternary salt When copolymerization is carried out in the presence of a copolymer and a cross-linking agent, the cross-linking sites in the polymer chain are formed in the polymer chain under the condition that a trace amount of a monomer having an active group having an active hydrogen as a cross-linking point exists. A method for producing a polymer flocculant, characterized in that the range is such that the yarn property, solubility, and coagulation performance are not negative. The crosslinking agent is monoglycidyl ether, diglycidyl ether, polyglycidyl ether, diepoxy compound, cyclic epoxy compound, diisocyanate, polyisocyanate, dimethylol phenol resin, polymethylol phenol resin, aziridine compound, amine compound and dialdehyde compound. The method for producing a polymer flocculant according to claim 3 .

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