Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/52—Amides or imides
  • C08F220/54—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide
  • C08F220/56—Acrylamide; Methacrylamide

Definitions

• the present invention relates to cationic water-soluble polyelectrolytes, in particular terpolymers of (meth) acrylamide, monomers based on cationic (meth) acrylic esters and monomers based on (meth) acrylamides and / or hydrolysis-stable cationic monomers, their preparation and use, and water-in Water-polymer dispersions containing such polyelectrolytes.
• Polymers made from non-ionic, anionic and cationic vinyl polymers are used as flocculants in wastewater treatment, ore and coal processing, and in paper manufacture.
• water-soluble, cationic polyelectrolytes which are used in large quantities worldwide in water treatment plants, in particular to improve the flocculation and dewatering of the resulting sewage sludge, and generally polymers from cationized acrylic acid derivatives or methacrylic acid esters or copolymers of these esters from acrylamide are.
• DE 35 44 909 describes copolymers of dimethylaminopropylacrylamide (DI-MAPA) and acrylamide (AA) in which the DIMAPA is either neutralized with mineral acids or quaternized with quaternizing agents and a proportion of cationic monomers between 4 and 80 mol% and have a quotient of viscosity and molar proportion of cationic component of greater than 200.
• DIMAPA dimethylaminopropylacrylamide
• AA acrylamide
• Such copolymers are characterized by very good storage and hydrolysis stability and therefore have advantages in sludge dewatering.
• EP 0 649 820 describes terpolymers of acrylamide, acrylic acid and cationic monomers in combination with alkaline earth metal salts and their use in
• No. 4,889,887 describes terpolymers of (meth) acrylamide, monomers based on (meth) acrylic esters and monomers based on (meth) acrylamides, which are used as constituents of acidic thickeners and their use in oil and natural gas production is described.
• HCl is added to terpolymers in order to crosslink them.
• the shelf life of such polymers is very limited because dilute 0.1 to 0.3% aqueous solutions have to be prepared from these polymers for use as flocculants.
• Such solutions are not very durable due to the hydrolysis-prone ester groups in the polymers.
• the document reports that the stability of acrylic derivatives in solution waters with pH values from 7.0 to 7.5 is only a few hours and that of methacrylic derivatives is approximately 24 hours.
• quaternized (meth) acrylamide-based copolymers have from one Cation activity of 20% by weight is so high in aquatic toxicity that such products can be labeled as environmentally hazardous.
• Chang et al. were able to show, however, that polymers based on quaternized (meth) acrylic acid esters are converted into the corresponding anionic polymers by hydrolysis, which have a significantly lower toxicity (cf. Chang et al., "Water Science Technology", vol. 44, no 2-3, 461-468, 2001).
• this object can be achieved by cationic water-soluble polyelectrolytes, in particular terpolymers, which can be obtained by polymerizing the monomers of (meth) acrylamide, a quaternized (meth) acrylamide derivative and a (meth) acrylic acid derivative and / or hydrolysis-stable cationic monomers , the composition of the polyelectrolytes by a toxicity index
• Q T p total cationic charge of the polymer in the context of the present invention is understood to mean the molar fraction in mol% of all cationic monomers in the polymer.
• Q ME charge fraction of the ester type monomer in the sense of the present invention is understood to mean the molar fraction in mol% of the ester type monomer in the polymer.
• the polyelectrolytes according to the invention have a total charge of 1 to 100 mol%, preferably 8 to 90 and particularly preferably 20 to 80 mol%, with a solution viscosity measured as a 1% solution in 10% NaCl solution of 10 to 2000 mPas, preferably 80 to 1500 mPas and particularly preferably have a solution viscosity of 100 to 1200 mPas.
• Polyelectrolytes which contain 0.1 to 30% by weight, preferably 3 to 25% by weight and particularly preferably 7 to 20% by weight of a high-cationic, low-molecular weight polyelectrolyte are particularly preferred.
• cationic monomers based on (meth) acrylic acid esters are preferably cationized esters of (meth) acrylic acid which contain a quaternized N atom.
• Quaternized dialkylaminoalkyl (meth) acrylates with d to C 3 in the alkyl or alkylene groups are preferably used.
• Dimethylaminoethyl acrylate which is quaternized with an alkyl halide, in particular with methyl chloride or benzyl chloride or dimethyl sulfate (ADAME quat) is particularly preferred.
• Monomers based on (meth) acrylamides which contain a quaternized N atom are used as cationic monomers. Quaternized dialkylaminoalkyl (meth) acrylamides with C 1 -C 3 in the alkyl or alkylene groups are preferably used. Dimethylaminopropylacrylamide which is quaternized with an alkyl halide, in particular methyl chloride or benzyl chloride or dimethyl sulfate, is particularly preferred.
• hydrolysis-stable cationic monomers can be all monomers which are to be regarded as stable according to the hydrolysis test according to OECD, such as, for example, diallyldimethylammonium chloride or water-soluble, cationic styrene derivatives.
• cationic polyelectrolytes are terpolymers of acrylamide, 2-dimethylammonium ethyl (meth) acrylate, which has been quaternized with methyl chloride (ADAME-Q) and 3-dimethylammonium propyl (meth) acrylamide, which has been quaternized with methyl chloride (DIMAPA-Q).
• the polyelectrolytes according to the invention can be prepared by known processes, such as, for example, emulsion, solution, gel and suspension polymerization, preferably gel and solution polymerization. It is essential to the invention, however, that the composition of the polyelectrolytes is characterized by the above-mentioned toxicity index With
• Such polyelectrolytes are preferably prepared by introducing the combination of the cationic monomers based on (meth) acrylic acid esters and monomers based on (meth) acrylamides and (meth) acrylamide and / or hydrolysis-stable cationic monomers in an aqueous solution and the polymerization initiated. During the polymerization, a solid gel forms from the monomer solution, which is then crushed, dried and ground.
• the polyelectrolytes according to the invention are preferably polymerized from the monomers mentioned above in aqueous solution.
• the solution obtained can be used directly for the production of the products according to the invention.
• the polymerization is preferably carried out as an adiabatic polymerization and can be started either with a redox system or with a photoinitiator. A combination of both start variants is also possible.
• the redox initiator system consists of at least two components - an organic or inorganic oxidizing agent and an organic or inorganic reducing agent.
• inorganic peroxides such as alkali metal and ammonium persulfate, alkali metal and ammonium perphosphates, hydrogen peroxide and its salts, in particular sodium peroxide, barium peroxide or organic peroxides such as benzoyl peroxide, butyl hydroperoxide or peracids such as peracetic acid.
• organic peroxides such as benzoyl peroxide, butyl hydroperoxide or peracids such as peracetic acid.
• other oxidizing agents can also be used, for example potassium permanganate, sodium and potassium chlorate, potassium dichromate, etc.
• Sulfur-containing compounds such as sulfites, thiosulfates, sulfinic acid, organic thiols, such as, for example, ethyl mercaptan, 2-hydroxyethanethiol, 2-mercaptoethylammonium chloride and thioglycol can be used as reducing agents and others are used.
• ascorbic acid and low-valent metal salts can be used, preferably copper (I), manganese (II) and iron (II) salts.
• Phosphorus compounds can also be used, for example sodium hypophosphite.
• the reaction is started with UV light, which causes the starter to decay.
• Benzoin and benzoin derivatives such as benzoin ether, benzil and its derivatives, such as benzil ketals, acryldiazonium salts, azo initiators such as, for example, 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2-amidinopropane) hydrochloride or acetophenone, can be used as starters. derivatives are used.
• the amount of the oxidizing and reducing components can range between 0.00005 and 0.5 percent by weight, preferably from 0.001 to 0.1 percent by weight based on the monomer solution and for photoinitiators between 0.001 and 0.1 percent by weight, preferably 0.002 to Move 0.05 percent by weight.
• the polymerization is carried out batchwise in an aqueous solution in a polymerization vessel or continuously on an endless belt, as described, for example, in DE 35 44 770.
• This document is hereby introduced as a reference and is considered part of the disclosure.
• the process is started at a temperature between -20 and 50 ° C, preferably between -10 and 10 ° C, and carried out at atmospheric pressure without the addition of external heat, the heat of polymerization resulting in a maximum final temperature of 50 to dependent on the content of polymerizable substance 150 ° C is obtained.
• the polymer present as a gel is comminuted.
• the comminuted gel is then dried discontinuously in a forced-air drying cabinet at 70 to 150 ° C., preferably at 80 to 130 ° C. Drying can be carried out continuously in the same temperature ranges on a belt dryer or in a fluidized bed dryer. After drying, the product is ground to the desired grain size.
• the water-soluble terpolymers of acrylamide, 2-dimethylammonium ethyl (meth) acrylate which has been quaternized with methyl chloride (ADAME-Q) and 3-dimethylammonium propyl (meth) acrylamide which has been quaternized with methyl chloride (DIMAPA-Q) are particularly fast according to the invention are very fast and are soluble without residue.
• the fish toxicity of the water-soluble polyelectrolytes, in particular terpolymers in solution which can be obtained by polymerizing the monomers (meth) acrylamide, quaternized (meth) acrylamide derivative and a (meth) acrylic acid derivative and / or hydrolysis-stable cationic monomers, the composition of the polyelectrolytes through the above-mentioned toxicity index F
• the polyelectrolytes according to the invention have a significantly better dewatering performance than corresponding products of the prior art.
• a method according to EP 0 649 820 game 3 produced terpolymer with 22.5 mol% cationic monomer (DIMAPA-Q), 22.5 mol% acrylic acid and 55 mol% acrylamide in the sludge dewatering tests a significantly lower dewatering performance.
• the dewatering performance was significantly below that of a cationic terpolymer according to the invention.
• the dissolving time for producing a 0.1% solution of the amphoteric polymer analogous to EP 0 649 820 was approximately 2 hours. A residue of approximately 20 g was found. The fish toxicity (OECD 203) of the product was above 100 mg / l.
• the polyelectrolytes according to the invention can be used with particular preference for dewatering sewage sludge, for cleaning waste water or treating drinking water or for producing paper or cardboard.
• such polyelectrolytes can also be used in water-in-water polymer dispersions, which are also the subject of the present invention.
• the viscosities were determined using a Brookfield viscometer on a 1.0% solution in 10% NaCl solution. The solving time was one hour.
• ADAME quat 2-dimethylammonium ethyl (meth) acrylate that has been quaternized with methyl chloride
• This test method is adapted to the drainage process used in practice, namely continuous pressure filtration using filter presses or centrifugal dewatering in centrifuges.
• This method usually tests organic cationic polymers with regard to their suitability for conditioning and dewatering of municipal or industrial sludges.
• the PCD device (type: 03 pH) from Mütek (D-82211 Herrsching) can be used for both qualitative and quantitative determination.
• the counterions are compensated for by adding mutually charged polyions until the polymer chains no longer have any external charges. This neutral point corresponds to the isoelectric point or inflection point of the titration.
• the polyelectrolyte requirement required for this neutralization then enables, with appropriate knowledge of the underlying polymer base of the product, a calculation of the ionicity.
• the polymers according to the invention can be produced by customary polymerization processes. These are preferably produced after the gel polymerization. An example of this is the polymerization, as shown in Example 1:
• 160.0 g of 50% aqueous acrylamide solution were initially placed in a polymerization vessel and mixed with 360.0 g of water and 0.15 g of Versenex 80. After the addition of 400.0 g of 60% DIMAPA quat solution and 80.0 g of acrylic acid, the pH was adjusted to 5.0 with 59 g of 50% sodium hydroxide solution, the mixture was cooled to -0.degree Blown out nitrogen. After the addition of 0.40 g of ABAH (2,2'-azobis (2-methylpropionamidine) dihydrochloride), the polymerization was started with UV light. The polymerization runs from -5 ° C to 80 ° C within 25 min. The polymer was ground with a meat grinder and dried at 100 ° C for 90 min. The product was ground to a grain size of 90-1400 ⁇ m.
• the polymerization was carried out as in Example 1, except that 275.0 g of ADAME quat, 360.0 g of acrylamide and 365.0 g of water were weighed out.
• the polymerization was carried out as described in Example 7, except that 240 g of acrylamide solution, 285.3 g of water and 466.7 g of DIMAPA quat were used. In addition, the polymerization was started at 7.5 ° C.
• the polymerization was carried out as in Example 8, except that it was started at 0 ° C. in order to obtain a higher viscosity.
• the polymers 18 to 20 are polymers according to the invention, while the polymers 16 and 17 are comparative examples.
• the polymers according to the invention were tested as retention aids for papermaking.
• This test works according to the recognized "Dynamic Drainage Jar” method.
• the fiber suspension is dewatered on a sieve with constant stirring - without building up a filter layer.
• the total and filler retention can be calculated by determining the solids content in the fiber sample and the filtrate This examination was carried out with a Mütek DFS 03.
• 1 L of a 1% fiber suspension was dewatered.
• the table shows the mass of water released.
• An 80% by weight cationic terpolymer (20% by weight of acrylamide, 40% by weight of ADAME quat and 40% by weight of DIMAPA quat) with a viscosity of 300 mPas was used in a sewage treatment plant Combination Zetag® 7848 FS 40 (trade name of an emulsion polymer from Ciba Specialty Chemicals AG) and Zetag 7587 (80% by weight Adame-Quat and 20% by weight acrylamide) tested. 7 kg of terpolymer according to the invention per ton of solid were required for dewatering on a chamber filter press, while 8 kg of polymer were required for the combination (emulsion converted to polymer).
• the dry matter content in the pressed sludge was the same.

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• 2002
  • 2002-08-30 DE DE10240797A patent/DE10240797A1/de not_active Withdrawn
• 2003
  • 2003-07-30 US US10/518,595 patent/US7375173B2/en not_active Expired - Fee Related
  • 2003-07-30 RU RU2005109152/04A patent/RU2321599C2/ru not_active IP Right Cessation
  • 2003-07-30 AU AU2003273393A patent/AU2003273393A1/en not_active Abandoned
  • 2003-07-30 EP EP03755548A patent/EP1539845A1/de not_active Withdrawn
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