Abstract: Method of purifying an open-chain N-vinyl compound by crystallization in a crystallizer, the crystallization being carried out from a melt of a mixture comprising open-chain N-vinyl compound at a pressure of 10?3 to 400 bar.

Abstract: The invention relates to a process for producing paper, board and cardboard of high dry strength by separately adding a polymer comprising vinylamine units and a polymeric anionic compound to a paper pulp, dewatering the pulp and drying the paper products, which comprises using as polymeric anionic compound at least one copolymer obtainable by copolymerizing (a) at least one N-vinylcarboxamide of the formula in which R1 and R2 are H or C1- to C6 alkyl, (b) at least one monoethylenically unsaturated monomer comprising acid groups, and/or the alkali metal, alkaline earth metal or ammonium salts thereof, and if appropriate (c) other monoethylenically unsaturated monomers, and if appropriate (d) compounds having at least two ethylenically unsaturated double bonds in their molecule.

Abstract: A process for producing a polymer powder comprising vinylformamide units by free radical polymerization of an aqueous solution of N-vinylformamide and if appropriate other monomers and drying the polymer which comprises an aqueous monomer solution comprising N-vinylformamide and at least one polymerization initiator being spray dispensed as an aerosol or dropletized at the top of a heatable tower-shaped reactor, then polymerizing the aerosol or droplets in an inert gas atmosphere to form a finely divided solid and discharging the finely divided polymer from the reactor.

Abstract: Aqueous dispersions of water-soluble polymers of N-vinylcarboxamides contain, based on 100 parts of water, (A) from 5 to 80 parts by weight of water-soluble polymer containing N-vinylformamide units and/or N-vinylacetamide units and having particle sizes of from 50 nm to 2 ?m and (B) from 1 to 50 parts by weight of at least one polymeric dispersant which is incompatible with the water-soluble polymers (A) in aqueous solution, which dispersions are prepared by polymerizing (A) from 5 to 80 parts by weight of N-vinylformamide and/or N-vinylacetamide, if desired together with other monoethylenically unsaturated monomers which form water-soluble polymers therewith, and (B) from 1 to 50 parts by weight of at least one polymeric dispersant which is incompatible with the polymers, formed from the monomers (A), in aqueous solution, in 100 parts by weight of water, at from 30 to 95° C. in the presence of from 0.001 to 5.

Abstract: Aqueous dispersions of water-soluble polymers of N-vinylcarboxamides contain, based on 100 parts of water, (A) from 5 to 80 parts by weight of water-soluble polymer containing N-vinylformamide units and/or N-vinylacetamide units and having particle sizes of from 50 nm to 2 ?m and (B) from 1 to 50 parts by weight of at least one polymeric dispersant which is incompatible with the water-soluble polymers (A) in aqueous solution, which dispersions are prepared by polymerizing (A) from 5 to 80 parts by weight of N-vinylformamide and/or N-vinylacetamide, if desired together with other monoethylenically unsaturated monomers which form water-soluble polymers therewith, and (B) from 1 to 50 parts by weight of at least one polymeric dispersant which is incompatible with the polymers, formed from the monomers (A), in aqueous solution, in 100 parts by weight of water, at from 30 to 95° C. in the presence of from 0.001 to 5.

Abstract: A process for fractionating water-soluble or water-dispersible amino-containing synthetic polymers having a broad molar mass distribution by ultrafiltration, wherein the polymer solution or dispersion to be fractionated is fed continuously into an ultrafiltration circulation with at least one ultrafiltration unit, and retentate having a narrower molar mass distribution and permeate are discharged continuously, in such a way that the ultrafiltration circulation is essentially in a steady state, the polymers obtainable by this process and their use.

Abstract: Paper, board and cardboard having high dry strength are produced by the addition of cationic, anionic and/or amphoteric starch as dry strength agents to the paper stock and drainage of the paper stock with sheet formation in the presence of cationic polymers as retention aids for starch, and cationic polymeric retention aids are used for increasing the retention of dry strength agents comprising cationic, anionic and/or amphoteric starch in the production of paper, board and cardboard.

Abstract: Agglomerated polymer particles of finely divided, water-soluble or water-swellable polymers containing ammonium carboxylate groups are prepared by azeotropic removal of water from water-in-oil emulsions of the water-soluble or water-swellable polymers which contain ammonium carboxylate groups in the presence of from 0.1 to 40% by weight, based on the polymers, of polyalkylene glycols which have an agglomerating effect and which are obtainable by an addition reaction of C2-C4-alkylene oxides with alcohols, phenols, amines or carboxylic acids and contain at least two polymerized alkylene oxide units and additionally of from 0.1 to 20% by weight, based on the polymers, of protective colloids which are obtainable by free radical copolymerization of C8-C40-monoolefins with monoethylenically unsaturated C4-C6-dicarboxylic anhydrides by a mass polymerization method at from 80 to 300° C.

Abstract: The invention relates to a method for producing water-soluble homopolymers and copolymers, comprising oligoalkylene-imine side chains of the general formula (I), wherein [AI]m, m, Y and x have the definitions given in claim 1, by radical homopolymerisation or copolymerisation of monomers A of the general formula (II), wherein [AI]m, m, n, Y and R have the definitions given in claim 1, in an aqueous reaction medium. The invention also relates to the homopolymers and copolymers obtained by this method and to their use as auxiliary agents in paper production.

Abstract: Agglomerated polymer particles of finely divided, water-soluble or water-swellable polymers containing ammonium carboxylate groups are prepared by azeotropic removal of water from water-in-oil emulsions of the water-soluble or water-swellable polymers which contain ammonium carboxylate groups in the presence of from 0:1 to 40% by weight, based on the polymers, of polyalkylene glycols which have an agglomerating effect and which are obtainable by an addition reaction of C2-C4-alkylene-oxides with alcohols, phenols, amines or carboxylic acids and contain at least two polymerized alkylene oxide units and additionally of from 0.1 to 20% by weight, based on the polymers, of protective colloids which are obtainable by free radical copolymerization of C8-C40-monoolefins with monoethylenically unsaturated C4-C6-dicarboxylic anhydrides by a mass polymerization method at from 80 to 300° C.

Abstract: A process for the elimination of formamide from polymers containing N-vinylformamide units involves treating formamide-containing polymers with from 1 to 2 mol-equivalents of an acid or a base, based on 1 mol-equivalent of formamide, under reaction conditions such that the N-vinylformamide units in the polymer undergo virtually no hydrolysis.

Abstract: Water-soluble polymers whose characteristic structural elements comprise units of the formulae I and/or II where R1 is H, alkyl, cycloalkyl, aryl or aralkyl, R2 and R3 independently are as defined for R1 or are selected from substituted alkyl, substituted cycloalkyl, substituted aryl or substituted aralkyl, the substituents being selected from OH, O-alkyl, O-aryl, SH, S-alkyl, S-aryl, NH2, NH-alkyl, NH-aryl, N(alkyl)2, possibly in protinated form, N(Alkyl)3+3Z−, where Z is the radical of an inorganic or organic acid, COOH, COO-alkyl, CONH2, CONH-alkyl, CON(alkyl)2, CN and SO3H; and the indices x are each independently an integer from 1 to 20; and the acid addition salts of these polymers, (processes for whose preparation are also described), are used in cosmetic compositions.

Abstract: Amphiphilic graft copolymers are prepared by grafting a pre-formed graft base polymer comprising at least 5% by weight of units of formula (I) where R1 and R2 are independently H or C1 to C6 alkyl groups. The monomer grafted to the pre-formed graft base polymer is at least one of styrene or a C1 to C2 alkylstyrene, and optionally other monoethylenically unsaturated monomers. At least 5 mole % of the groups are cleaved from the grafted copolymer thus formed.

Abstract: Starch is modified with at least one cationic polymer P) and the modified starch is prepared by a process in which a) an anionically modified starch A) is reacted with a cationic polymer P) or b) a natural starch B) or a starch C) which has not been anionically modified is reacted with the cationic polymer P) in the presence of an anionic modifier M) and the polymer-modified starch is used.

Abstract: W/O emulsions comprising dispersed therein crosslinked, water-swellable polymers consisting of a) 35-100% by weight of ionic monomers, b) 0-65% by weight of nonionic monomers, c) 0.3-1 mol-%, based on a) and b), of at least one at least bifunctional monomer, where the oil phase consists of one or more fatty acid esters, are used as thickeners in cosmetic or pharmaceutical formulations.

Abstract: Wastewaters and circulation waters in papermaking, in deinking and in pulp bleaching are treated by adsorption of water-soluble anionic compounds and compounds dispersed in water from the wastewaters and circulation waters over finely divided adsorbents which consist of insoluble, only slightly swellable polymers which contain polymerized vinylamine units, and these polymers are used as adsorbents for treating water circulations in papermaking and for treating paper machine wastewaters and wastewaters from the deinking process and from pulp bleaching.

Abstract: Partially hydrolyzed polymers of N-vinylcarboxamides obtainable by sole polymerization of N-vinylcarboxamides of the formula ##STR1## where R.sup.1 and R.sup.2 are each hydrogen or C.sub.1 - to C.sub.6 -alkyl, and elimination from the polymers of from 0.5 to 95 mol % of the groups of the formula ##STR2## where R.sup.1 is hydrogen or C.sub.1 - to C.sub.6 -alkyl, can be used as paper, paperboard and cardboard dry strength enhancers.

Abstract: A starch modified with at least one cationic polymer is prepared by a process in which dry, free-flowing starch is initially taken and the cationic polymer is applied thereon without the starch particles sticking together, and the polymer-modified starch is used.

Abstract: An insoluble, only slight swellable, polymer having modified amino groups, which contain units of the formulae: ##STR1## or both (I) and (II), wherein R.sup.1, R.sup.2, R.sup.3 and Me are as defined herein.

Abstract: The present invention relates to a W/O emulsion comprising cross-linked, water-swellable polymers consisting ofa) 35-100% by weight of ionic monomers,b) 0-65% by weight of non-ionic monomers,c) 0.3-1 mol-%, based on a) and b), of one or more at least bifunctional monomer.The oil phase of the W/O emulsion consists of polyglycerol fatty acid esters and comprises at least one fatty acid ester of diglycerol or triglycerol with caprylic or capric acid. The W/O emulsions are usefull as thickeners for cosmetic or pharmaceutical compositions.