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: 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: 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.

Abstract: Graft polymers are obtainable by free radical polymerization of(A) monomers or monomer mixtures comprising(a) from 1 to 100% by weight of N-vinylcarboxamides of the formula ##STR1## where R.sup.1 and R.sup.2 are each H or C.sub.1 -C.sub.6 -alkyl, (b) from 0 to 99% by weight of other monoethylenically unsaturated monomers copolymerizable with the monomers (a) and(c) from 0 to 5% by weight of monomers having at least two ethylenically unsaturated, nonconjugated double bonds in the molecule,in the presence of(B) polymers which contain units of vinyl esters of saturated C.sub.1 -C.sub.

Abstract: Polymers containing .beta.-hydroxyalkylvinylamine units, which are obtainable by reacting polymers containing vinylamine units with epoxides of the formula ##STR1## where R=C.sub.2 -C.sub.28 -alkyl, phenyl, C.sub.1 -C.sub.18 -alkylphenyl or C.sub.2 -C.sub.18 -alkenyl, are described, as are a process for preparing the polymers and use of the polymers as retention and drainage aids and flocculants and as fixatives in paper making, as protective colloid for producing alkyldiketene dispersions or alkenylsuccinic anhydride dispersions, as emulsifier for producing aqueous filler suspensions and as corrosion inhibitor.

Abstract: A graft polymer obtained by free radically polymerizing:(A) a monomer or monomer mixture comprising:(a) from 10-100% by weight of a N-vinylcarboxamide of the formula: ##STR1## where R.sup.1 and R.sup.2 are each H or C.sub.1 -C.sub.6 -alkyl, (b) from 0-90% by weight of at least one other monoethylenically unsaturated monomer which is copolymerizable with (a), and(c) from 0-5% by weight of at least one monomer having at least two ethylenically unsaturated nonconjugated double bonds in the molecule, in the presence of(B) a polytetrahydrofuran or a polymer which contains at least 3 units of a C.sub.2 -C.sub.4 alkylene oxide and is a hornopolymer of C.sub.2-4 -alkylene oxide having two free terminal OH groups or random or block copolymers of C.sub.2-4 -alkylene oxides having two free terminal OH groups or the reaction products of C.sub.