The present invention provides: (1) a polymer flocculant comprising a cationic copolymer that has a cationic monomer as an essential structural unit thereof, said polymer flocculant being characterized in that the cationic copolymer has, at an end thereof, a structure derived from a degenerative chain transfer mechanism-type control agent; and (2) a polymer flocculant characterized by comprising a block copolymer of a polymer block (A) which is formed by polymerizing a monomer component (a) and a polymer block (B) which is formed by polymerizing a monomer component (b), wherein the polymer block (A) has, at an end thereof, a structure derived from a degenerative chain transfer mechanism-type control agent, the polymer block (A) is non-ionic unit, and the polymer block (B) is a cationic unit.
B01D 21/01 - Separation of suspended solid particles from liquids by sedimentation using flocculating agents
C02F 11/147 - Treatment of sludgeDevices therefor by de-watering, drying or thickening with addition of chemical agents using organic substances
C08F 293/00 - Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule
2.
POWDER OF (METH)ACRYLAMIDE-BASED WATER-SOLUBLE POLYMER AND PRODUCTION METHOD THEREFOR
The present invention provides a powder of a (meth)acrylamide-based water-soluble polymer, the powder comprising a polymer including monomer units at least derived from a (meth)acrylamide compound and a thiosulfuric acid salt, characterized in that the content of the thiosulfuric acid salt is 2×10-3 mol% or higher with respect to all the monomer units constituting the polymer.
The present invention addresses the problem of providing a high-performance macromolecular coagulant in powder form that shows outstanding dehydration performance on dehydration-resistant sludge, resolves transportation cost problems, and can be used in existing general-purpose equipment such as automatic powder melting devices and the like that have been in wide use. In particular, the present invention addresses the problem of providing an outstanding polymer coagulant that, in addition to exhibiting outstanding dehydration performance on dehydration-resistant sludge, can perform dehydration processing with only a small amount thereof. These problems can all be solved by a macromolecular coagulant in powder form that includes a water-soluble polymer (A) that shows specific solution properties and a water-soluble polymer (B) that shows solution properties different from those of the water-soluble polymer (A). That is, this macromolecular coagulant in powder form exhibits outstanding dehydration performance, resolves transportation cost problems, and can be used in existing general-purpose equipment such as automatic powder melting devices and the like that have been in wide use.
Provided is a method for producing a polymer coagulant powder by drying a polymer emulsion obtained by emulsion polymerization of a monomer mixture containing at least a cationic monomer and a crosslinkable monomer, the method including: a step (A) which is an emulsifying step of preparing a water-in-oil type monomer emulsion having an emulsified particle median diameter of 10 µm or less; a step (B) which is a polymerization step of preparing a water-in-oil type polymer emulsion; a step (C) which is a reflux dehydration step of preparing a polymer dispersion by discharging water contained in a condensate, which is obtained by evaporating off water and hydrocarbons from the water-in-oil type polymer emulsion and condensing the water vapor, to outside the system and returning the hydrocarbons to the system, thereby removing water until the dehydration rate is within the range 65-99%, with the mass of the hydrocarbons being 0.6-2.0 times the mass of solid content in the water-in-oil type polymer emulsion; and a step (D) which is a drying step of preparing a polymer powder by removing hydrocarbons and water from the dispersion.
The present invention provides a polymer-coagulating agent which comprises a crosslinked polymer, wherein the crosslinked polymer is produced by the radical polymerization of a monomer mixture that comprises at least a cationic monomer and a (meth)acrylate-type crosslinkable monomer having at least three (meth)acryloyl groups per molecule.
Disclosed is a mucilaginous agent for polyacrylamide papermaking that is characterized by comprising a nonionic polyacrylamide-water soluble cationic polymer complex — produced by mixing molecular units of a water-soluble cationic polymer and a nonionic polyacrylamide — and an anionic polyacrylamide, in a mass ratio of between 10:90 and 90:10.
Disclosed is a powdered nonionic thickening agent that is for papermaking and that is characterized by comprising, at a mass ratio of 20:80 to 80:20: a powder of a nonionic acrylamide polymer-water soluble cationic macromolecule complex formed from mixing a nonionic acrylamide polymer and a water soluble cationic macromolecule in molecular units; and a powder of a polyethylene oxide.
Disclosed is a polyacrylamide thickening agent for papermaking that allows pulp break-up to be maintained, and produces paper with a more pleasant texture, even if cationic polyelectrolytes used for example as a wet strength agent coexist with a pulp slurry when making light-stock papers such as sanitary paper. The thickening agent for papermaking is comprised of a non-ionic acrylamide polymer and a water-soluble cationic polymer. An aqueous solution of 0.10% concentration of the thickening agent for papermaking containing a concentration of 1 mol/L common salt has a viscosity of 3.5-6.0 mPa·s at 25°C where the thickening agent has a degree of ionisation of -0.30-0.7 meq/g ata pH of 7.
A method of dissolving a water-soluble polymer which comprises diluting 2-30 times a primary aqueous solution (8) containing, dissolved therein, 0.3-1 mass% water-soluble polymer just before use to prepare a secondary aqueous solution and subjecting the secondary aqueous solution to an application as a polymeric coagulant, yield improver for papermaking, thickener, paper strength agent, etc. For diluting the primary aqueous solution to prepare the secondary aqueous solution, it is preferred to use an in-line mixer (4). By using the dissolution method, an aqueous water-soluble-polymer solution can be provided which does not decrease in viscosity and can be used over long.
A process for continuously producing a quaternary salt of a dialkylaminoalkyl (meth)acrylate by reacting a dialkylaminoalkyl (meth)acrylate with a gaseous quaternizing agent in an aqueous solution of a quaternary salt of a dialkylaminoalkyl (meth)acrylate. The process attains an improvement in the efficiency of the reaction of the gaseous quaternizing agent and inhibits acrylic acid from generating as a by-product. A dialkylaminoalkyl (meth)acrylate, a gaseous quaternizing agent, and water are fed to an aqueous solution of a quaternary salt of a dialkylaminoalkyl (meth)acrylate held in a reactor (11) to thereby react the dialkylaminoalkyl (meth)acrylate with the quaternizing agent. In this operation, the quaternizing agent is continuously supplied in the form of bubbles (2) having an average diameter of 100 쎽m or smaller.
C07C 213/02 - Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton by reactions involving the formation of amino groups from compounds containing hydroxy groups or etherified or esterified hydroxy groups
C07C 219/08 - Compounds containing amino and esterified hydroxy groups bound to the same carbon skeleton having esterified hydroxy groups and amino groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated having at least one of the hydroxy groups esterified by a carboxylic acid having the esterifying carboxyl group bound to an acyclic carbon atom of an acyclic unsaturated carbon skeleton
The invention provides processes for dewatering digested sewage sludge which can give floc excellent in aggregation, filterability and the clarity of separated liquid with reduction in the amount of flocculant used and which brings about lowering in the water content of dehydrated cake. The invention relates to a process for dewatering digested sewage sludge which is characterized by adding a cationic polymer flocculant containing a polymer which contains cations in an amount of 4.0meq/g or above and exhibits a 0.5% salt viscosity of less than 40mPa s to digested sewage sludge and then dewatering the resulting sludge with a belt press or filter press; and a process for dewatering digested sewage sludge which is characterized by subjecting digested sewage sludge to centrifugal dehydration without an inorganic flocculant either while or after adding a cationic polymer flocculant containing a polymer which contains cations in an amount of 4.0meq/g or above and exhibits a 0.5% salt viscosity of 40mPa s or above to the sludge.
It is intended to provide a method of dewatering sludge which exhibits an excellent aggregation and dehydration performance on a sludge containing little coarse float and having a high excessive sludge rate. Namely, a method of dewatering sewage sludge, wherein the sewage sludge is a first precipitated sludge formed by a sewage disposal treatment, an excessive sludge or a mixed sludge comprising a first precipitated sludge and an excessive sludge that has a ratio of coarse float (CF) to suspended solids (SS) of 15% by mass or less, characterized by comprising adding a cationic high molecular aggregating agent containing a polymer having 65% by mol or more of a cationic monomer having acryloyl groups in all of the constituting monomer units thereof to the sewage sludge followed by dewatering without resorting to polyamidine.
Disclosed is a method for producing a DAM at high productivity and high purity by cooling a reaction solution efficiently to control the increase in temperature in a reactor. Also disclosed is a production apparatus suitable for the method. Specifically disclosed is a method for producing a dialkylaminoalkyl (meth)acrylate quaternary salt by continuously feeding a dialkylaminoalkyl (meth)acrylate, a quaternarizing agent and water to a reactor, while continuously draining a reaction solution from the reactor, wherein a part of the reaction solution is drained from the reactor, is cooled by passing through a heat exchanger, and then is fed into the reactor together with the quaternarizing agent by means of an ejector.
C07C 213/08 - Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton by reactions not involving the formation of amino groups, hydroxy groups or etherified or esterified hydroxy groups
14.
METHOD FOR PRODUCTION OF DIALKYLAMINOALKYL (METH)ACRYLATE QUATERNARY SALT
Disclosed is a method for producing a DAM at high productivity and high purity while keeping safety, by adjusting the gas composition in a gas phase in a reactor to a value falling within the predetermined range. Specifically disclosed is a method for producing a dialkylaminoalkyl (meth)acrylate quaternary salt by feeding a dialkylaminoalkyl (meth)acrylate, methyl chloride and water to a reactor, wherein the reaction is conducted while adjusting the concentration of oxygen ([O2]), the concentration of methyl chloride ([MC]), and the ratio of the concentration of oxygen to that of methyl chloride ([O2]/[MC]) in the gas phase in the reactor to 3 to 12 vol%, 22 to 80 vol% and 0.05 to 0.5, respectively.
C07C 213/08 - Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton by reactions not involving the formation of amino groups, hydroxy groups or etherified or esterified hydroxy groups
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