Abstract: The invention relates to a method for purifying water and for dewatering sludge, comprising the following steps: bringing a surface-treated natural calcium carbonate, a natural bentonite and an anionic polymer into contact with the water or sludge, flakes being formed as a result of the agglomeration of particulate materials contained in said water or sludge, and separating said formed flakes so as to obtain purified water, or separating water in order to obtain dewatered sludge. The surface-treated natural calcium carbonate is a product of a reaction of natural calcium carbonate with an acid and carbon dioxide, which is formed in situ by the acid treatment and/or is fed from outside, and is produced as an aqueous suspension with a pH greater than 6.0 measured at 20° C. The invention also relates to a composition comprising said surface-treated natural calcium carbonate, a natural bentonite, and an anionic polymer, for the purpose of purifying water or dewatering sludge.

Abstract: The invention relates to a process for the purification of water and/or dewatering of sludges and/or sediments, to the use of a surface-treated calcium carbonate for water purification and/or dewatering of sludges and/or sediments, as well as to the use of a surface-treated calcium carbonate for reducing the amount of polymeric flocculation aids in water and/or sludges and/or sediments and to a composite material comprising a surface-treated calcium carbonate and impurities originated from different sources obtainable by said process.

Abstract: The invention relates to water-soluble, preferably powder-form polymer compositions which are obtained by continuous polymerization of at least one unsaturated monomer. At least one parameter that influences the polymerization is varied according to a recurrent pattern. The invention also relates to the use of the inventive polymer compositions and to a method for producing them.

Abstract: The present invention relates to powdered, crosslinked polymer compositions, containing a) 55-99.9 wt.-% of at least one polymerized, ethylenically unsaturated, polymerizable monomer which contains acid groups neutralized to at least 25 mole-%, b) 0-40 wt.-% of polymerized, unsaturated monomers copolymerizable with a), c) 0.01-5.0 wt.-%, preferably 0.1-2.0 wt.-% of one or more crosslinking agents, d) 0-30 wt.-% of a water-soluble polymer, the weight amounts a) through d) being based on anhydrous polymer composition, and the sum of these components always being 100 wt.-%, which compositions can be obtained by continuous polymerization wherein at least one parameter biasing the polymerization is varied according to a recurring pattern. The present invention also relates to a process for their production and to their use.

Abstract: The invention relates to a process for dewatering sewage sludges using plate filters, wherein the flocculated sewage sludge treated by means of organic polymer flocculation aids and optionally other auxiliary agents is separated from the major amount of water of the flocculated sewage sludge on a plate filter by means of hydrostatic filtration, whereafter the partially dewatered sewage sludge is subjected to pressure filtration. The plate filters employed have filtrate outlet systems permitting filtrate discharge at a flow rate of 1.0 m/s at maximum. By conducting the process in this way, the dewatering capacity is substantially increased.

Abstract: A compacted granulate and a method for making the same, comprises 60-99 wt.-% of a water-insoluble, water-swellable cellulose and optionally at least one water-swellable polysaccharide derivative, 1-40 wt.-% of at least one polymeric binder of a polymer or a copolymer of (meth)acrylic acid and/or salts thereof, and at least one liquid surfactant, in which the granulate has a water content of from 2 to 8 wt.-%.

Abstract: A compacted granulate comprising water-swellable cellulose and/or cellulose derivatives and finely divided polymers/copolymers of (meth)acrylic acid or salts thereof and one or more liquid surfactants, and the use thereof as disintegrating agent for detergent tablets, cleaning agent tablets, water softening tablets and scouring salt tablets, as well as a process for making the compacted granulate by mixing the constituents, granulating and compacting.

Abstract: A water-soluble, powdered, cationic polyelectrolyte comprising a copolymer of acrylamide and dimethylaminopropylacrylamide which is essentially free of bifunctional compounds and in which a) the dimethylaminopropylacrylamide is quaternized; b) the quotient of the intrinsic viscosity of the copolymers divided by the molar ratio of acrylamide to dimethylaminopropylacrylamide is greater than 200; and c) the proportion of the cationic monomers in the polymer is between 4 and 80 mol-%, the copolymer having been obtained by copolymerization of acrylamide and quaternized dimethylaminopropylacrylamide said quaternized dimethylaminopropylacrylamide having been obtained by the reaction of dimethylaminopropylacrylamide with a quaternizing agent in the absence of acrylamide.

Abstract: Compacted granulate comprising starch and/or a starch derivatives and, optionally, water-swellable cellulose/cellulose derivatives, and finely divided polymers/copolymers of (meth)acrylic acid or salts thereof and one or more liquid surfactants, and the use thereof as disintegrating agent for detergent tablets, cleaning agent tablets, water-softening tablets and scouring salt-tablets, as well as a process for making the compacted granulate by mixing the constituents, granulating and compacting.

Abstract: The present invention relates to superabsorbent cross-linked polymers for watery liquids, which are built-up of partially neutralized monomers having monoethylenlcally unsaturated acid groups, optionally further monomers copolymerizable therewith, as well as polymers optionally suitable as graft basis, and which can be manufactured by using a cross-linker/monomer combination ofCH.sub.2 .dbd.CHR.sup.6 --CO--(OCHR.sup.3 --CHR.sup.3).sub.z O--CH.sub.2 --CHR.sup.6 .dbd.CH.sub.2CH.sub.2 .dbd.CHR.sup.6 --R.sup.5 --(OCHR.sup.3 --CHR.sup.3).sub.v OR.sup.4R.sup.1 --?O(CHR.sup.3 --CHR.sup.3 O).sub.u --CO--R.sup.2 !.sub.x, and/or di- or triallylamine and/or bisacrylamidewithR.sup.1 : multivalent C2-10-alkyl,R.sup.2 : linear or branched C2-10-alkenyl,R.sup.3 : H, CH.sub.3, C.sub.2 H.sub.5,R.sup.4 : H, linear or branched C1-10-alkyl,R.sup.6 : CO, CH.sub.2R.sup.8 : H, CH.sub.

Abstract: In a device for dissolving water-soluble, powdery polymers which has a pipe with an inlet to introduce the polymer solution containing gel components and an outlet to discharge the polymer solution, the gel content in the polymer solution is reduced without reducing the viscosity of the polymer solution by means of the fact that the pipe is formed of a plurality of pipe sections which are provided with filters and can be connected with one another.

Abstract: The present invention relates to powdery, insoluble, water-swellable, cross-linked polymers absorbing water, aqueous or serous liquids, which are formed ofa) 55-99.9%-wt. polymerized unsaturated, polymerizable acid-groups--comprising monomers which are neutralized to the extent of at least 25 mol-%,b) 0-40%-wt. polymerized unsaturated monomers which are co-polymerizable with a),c) 0.1-5.0%-wt. of a cross-linking agent, andd) 0-30%-wt. of a water-soluble polymer,with the weight amounts of a) to d) being relative to anhydrous polymer, and the polymer powder is heated with an at least bifunctional compound reactive with acid groups to a temperature of 150.degree. C.-250.degree. C. under cross-linkage of the surface, and the polymer powder that is thus already surface-cross-linked is subjected to a repeated surface-cross-linking treatment using an at least bifunctional compound reactive with acid groups at a temperature of 150.degree. to 250.degree. C.

Abstract: A water-soluble, powdered, cationic polyelectrolyte comprising a copolymer of acrylamide and dimethylaminopropylacrylamide in whicha) the dimethylaminopropylacrylamide is neutralized with mineral acids;b) the quotient of the intrinsic viscosity of the copolymers divided by the molar ratio of acrylamide to dimethylaminopropylacrylamide is greater than 200; andc) the proportion of the cationic monomers in the polymer is between 4 and 80 mol-%,the copolymer having been obtained by copolymerization of acrylamide and dimethylaminopropylacrylamide that is essentially free of bifunctional compounds.

Abstract: The present invention relates to a process for trash removal or pitch control in the paper manufacture, in which process as agent for the trash removal or pitch control cationic groups containing polymers of 50 to 100%-wt. quaternized dimethylaminopropylmethacrylamide or dimethylaminopropylmethacrylamide and 0 to 50%-wt acrylamide, acrylic acid, methacrylic acid, acrylamidomethylpropanesulfonic acid, are used, which polymers have an intrinsic viscosity of smaller than 150 ml/g. The trash removal or pitch control agent is added to the pulp flow and/or the circuit water in amounts of up to 1%-wt., relative to the dry weight of the paper manufactured.

Abstract: The present invention relates to amphoteric water soluble polymers which containa) 90 to 30%-wt acrylic acid and/or methacrylic acidb) 10 to 60%-wt of a compound of the formula ##STR1## wherein R.sub.1 stands for hydrogen or the methyl radical, R.sub.2 and R.sub.3, which are the same or different, stand for the methyl or ethyl radical, and an optionally branched alkaline radical with 1 to 5 C atoms stands for Xand optionally, up to 50%-wt of acrylamidomethylpropane sulfonic acid and up to 10%-wt of a further ethylenically unsaturated compound, the molecular weight of these polymers, measured at a pH value of 8.0, being smaller than 100,000. The present invention also relates to the process for producing these polymers, and their use as grinding or dispersing agents for the production of highly concentrated aqueous pigment suspensions.

Abstract: The present invention relates to a process to improve the organoleptic behavior and the physical characteristics of leather by the use of aqueous solutions of copolymers of 90 to 20%-wt acrylic acid or methyacrylic acid, as well as 10 to 80%-wt of a monomer of the formula ##STR1## wherein R.sub.1 is hydrogen or methyl; R.sub.2 and R.sub.3, which are equal or different, are methyl or ethyl; x stands for an optionally branched alkylene radical with 1 to 5 carbon atoms; the amine nitrogen is optionally neutralized or quaternized; and the molecular weight of the copolymer, measured at a pH of 8.0, is less than 100,000. The concentration of the copolymer in the aqueous solution is 0.02 to 10%-wt, relative to the shaved weight of the leather.

Abstract: The present invention relates to a process to improve the organoleptic behaviour and the physical characteristics of leather by the use of aqueous solutions of copolymers of 90 to 20%-wt acrylic acid or methyacrylic acid, as well as 10 to 80%-wt of a monomer of the formula ##STR1## wherein R.sub.1 is hydrogen or methyl; R.sub.2 and R.sub.3, which are equal or different, are methyl or ethyl; x stands for an optionally branched alkylene radical with 1 to 5 carbon atoms; the amine nitrogen is optionally neutralized or quaternized; and the molecular weight of the copolymer, measured at a pH of 8.0, is less than 100,000. The concentration of the copolymer in the aqueous solution is 0.02 to 10%-wt, relative to the shaved weight of the leather.

Abstract: The invention relates to a process for separating mineral finest grain from coal slurries or washings obtained in coal processing, by treating the washing with a selective anionic dispersing agent for the finest grain, having a molecular weight of .ltoreq.10000 g/mol, and subsequent selective flocculation of the coal by means of a flocculating agent known per se.