Abstract: Paper is produced by draining a paper stock containing process chemicals on a paper machine, a main stream of the paper stock and a dilution stream which consists of white water, contains at least 5% by weight of the process chemicals and amounts to 5-35% by volume of the total head box feed being fed via a head box to the paper machine wire. The papers thus produced have an excellent formation profile and an outstanding ash distribution.

Abstract: Aqueous pigment slurries which contain up to 80% by weight of a finely divided pigment in dispersed form and from 0.1 to 5% by weight of a water-soluble reaction product of(a) a polyamidoamine grafted with ethyleneimine and(b) a bifunctional or polyfunctional crosslinking agents which have a halohydrin, glycidyl, aziridine or isocyanate unit or a halogen atom as a functional group,the reaction product, in 25% strength by weight aqueous solution at 20.degree. C., having a viscosity of at least 100 mPa.s, are used as an additive to the paper stock in the production of filler-containing paper.

Abstract: Paper, board and cardboard are produced by draining a paper stock, containing undesirable substances, in the presence of hydrolyzed homo- and/or copolymers of N-vinylformamide having a degree of hydrolysis of not less than 60% and a cationic retention aid. According to the invention, faster drainage and improved retention are obtained compared with the use of known fixing agents.

Abstract: Paper, board, and cardboard having high dry strength are made by adding to the paper stock a dry strength agent which is obtainable by mixing enzymatically digested starch having a viscosity of from 20 to 2,000 mPa.s (measured in 7.5% strength aqueous solution at 45.degree. C.) and a cationic polymer which contains, as typical copolymerized monomers,(a) diallyldimethylammonium chloride,(b) N-vinylamine or(c) an unsubstituted or substituted N-vinylimidazoline, the K value of the cationic polymer in each case being not less than 30, and draining the paper stock with sheet formation.

Abstract: The printability of paper is improved by applying an aqueous coating agent consisting of(a) 100 parts by weight of a finely divided pigment,(b) from 5 to 70 parts by weight, based on solids, of a cationic aqueous polymer dispersion of a paper size and(c) from 0.01 to 10 parts by weight of a surfactant which interferes with the formation of the surface size and/or of a polymeric dispersantin an amount of from 0.5 to 4 g/m.sup.2 to one or both surfaces of the paper and drying the coated paper.

Abstract: Aqueous pigment suspensions which are added to the stock suspension during papermaking and contain, as a dispersant, from 0.1 to 2% by weight, based on the pigment, of a copolymer which contains, as copolymerized units,(a) from 40 to 95% by weight of an ester of (meth)acrylic acid with a saturated monohydric C.sub.1 -C.sub.8 -alcohol or with a saturated dihydric C.sub.2 -C.sub.4 -alcohol and(b) from 60 to 5% by weight of an ethylenically unsaturated C.sub.3 -C.sub.5 -carboxylic acidand has a K value of from 10 to 65 (determined according to H. Fikentscher in 1% aqueous solution in the form of the ammonium salt at pH 9 and at 20.degree. C.), their preparation and their use.

Abstract: Paper, board and cardboard are produced by draining a pulp slurry in the presence of high molecular weight, water-soluble polymers of N-vinylamides as drainage aids, retention agents and flocculants. These polymers are particularly effective in a pulp slurry which has a high content of interfering substances and other phenolic compounds.

Abstract: Paper and cardboard are produced by draining a paper stock by a method in which a stock having a consistency of from 2.5 to 5% by weight is used as a starting material, and (a) from 0.1 to 2% by weight of an activated bentonite are added and the stock consistency is then brought to 0.3-2% by weight by dilution with water, after which (b) from 0.01 to 0.1% by weight of a cationic polyelectrolyte having a charge density of not less than 4 meq/g of polyelectrolyte is added and distributed therein, and, after thorough mixing (c) from 0.003 to 0.3% by weight of a high molecular weight polymer based on acrylamide or methacrylamide is metered in and mixed with the paper stock, the percentages in each case being based on dry paper stock, and the resulting pulp is drained on a wire. The paper obtained is distinguished in particular by good printing properties in the offset printing process.

Abstract: A process for removing anionic compounds from water which is recycled in manufacturing processes, and from waste water, by adding (1) water-soluble products obtained by reacting an alkylating agent, having an aromatic substituent, with a cationic polyelectrolyte and (2) mineral adsorbents and/or a magnesium salt, aluminum salt or iron salt, with formation and flocculation of water-insoluble reaction products.

Abstract: Crosslinked water-soluble reaction products for the papermaking industry obtained by reacting(a) 1 part by weight of a polyamidoamine obtained by condensation of 1 mole of a dicarboxylic acid with from 0.8 to 1.4 moles of a polyalkylenepolyamine such as diethylenetriamine, up to 8 ethyleneimine units per basic nitrogen atom being optionally grafted onto the condensation product, with(b) from 0.3 to 2 parts by weight of a reaction product of a polyalkylene oxide having from 8 to 100 alkylene oxide units with epichlorohydrin,In aqueous solution at a temperature of from 20.degree. to 100.degree. C., the solution having a solids content of from 5 to 50% by weight. The viscosity of an aqueous solution containing 20% of the reaction product is from 300 to 2,500 centipoises at 20.degree.C.

Abstract: Production of water-soluble crosslinked auxiliaries for the papermaking industry by reactingA. one equivalent of NH groups of a polyalkylene polyamine having from 15 to 500 alkyleneimine units withB. from 0.001 to 0.08 mole of a reaction product obtained from a polyalkylene oxide having from 8 to 100 alkylene oxide units with epichlorohydrin,In aqueous solution at a temperature of from 20.degree. to 100.degree. C. The viscosity of an aqueous solution containing 20% by weight of the crosslinked auxiliaries is from 300 to 1,500 centipoises (20.degree. C).