Abstract: A process for the preparation of aqueous polymer dispersions is described, a vinylaromatic compound, such as, for example, styrene, a conjugated aliphatic diene, such as, for example, butadiene, and an ethylenically unsaturated carbonitrile, such as, for example, acrylonitrile, being copolymerized in an aqueous medium. The copolymerization is effected in the presence of a degraded starch and of free radical initiators. At least part of the monomers differing from ethylenically unsaturated carbonitriles are polymerized before the ethylenically unsaturated carbonitriles are added to the polymerization mixture.

Abstract: Described are aqueous polymer dispersions and methods of making them. The polymer dispersions are obtainable by free-radically initiated emulsion polymerization of 19.9 to 80 parts by weight of vinylaromatic compounds, 19.9 to 80 parts by weight of acrylate monomers selected from C1-C10 alkyl acrylates and C1-C10 alkyl methacrylates, 0.1 to 10 parts by weight of ethylenically unsaturated acids, and 0 to 20 parts by weight of other ethylenically unsaturated monomers, wherein the emulsion polymerization is effected in an aqueous medium in the presence of free-radical initiators, seed latex and also at least one carbohydrate compound in the form of a degraded starch. The polymer dispersions are particularly useful in the manufacture of paper coating slips.

Abstract: The present invention relates to a process for producing polymer fibers, especially nano- and mesofibers, by electrospinning a colloidal dispersion of at least one essentially water-insoluble polymer in an aqueous medium, and to fibers obtainable by this process, to textile fabrics comprising the inventive fibers, and to the use of the inventive fibers and of the inventive textile fabrics.

Abstract: A paper coating slip comprising at least one inorganic pigment and, based on 100 parts by weight of the inorganic pigments, less than 40 parts by weight of organic polymers and less than 25 parts by weight of water or other solvents having a boiling point below 150° C. at 1 bar.

Abstract: Process for the production of filler-containing papers and filler-containing paper products by addition of an aqueous suspension of at least one finely divided polymer-pigment hybrid to a paper stock and drainage of the paper stock with sheet formation, the polymer-pigment hybrid being obtainable by milling an aqueous suspension of at least one inorganic pigment in the presence of at least one binder and, if appropriate, by drying the aqueous suspension thus obtainable and redispersing the dried polymer-pigment hybrid in water, and the use of the polymer-pigment hybrids thus obtainable as a filler for the production of filler-containing paper or filler-containing paper products.

Abstract: An aqueous paper coating slip comprising organic polymers as binders and inorganic pigments, wherein the binders are present at least partly in the form of a pigment-polymer hybrid in which the binder is chemically or physically bound to the inorganic pigments.

Abstract: An aqueous polymer dispersion is prepared by free radical aqueous emulsion polymerization of at least one ethylenically unsaturated compound (monomer) in the presence of at least one dispersant and at least one water-soluble and one oil-soluble free radical initiator by a process in which the polymerization temperature increases from the starting reaction temperature TS to the end reaction temperature TE in the course of the polymerization reaction.

Abstract: A process for preparing a polymer powder by evaporating the volatile constituents from an aqueous dispersion of a film-forming polymer P, wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion still comprises drying assistants T, present in an amount of from 0.1 to 80% by weight, based on the polymer P of the dispersion, and there being used as drying assistant T polyvinylformamide. The polyvinylformamide used preferably has a K value (KW), determined by the method of Fikentscher in accordance with DIN 53726, of from 5 to 50.

Abstract: The present invention provides a process for preparing a stable aqueous copolymer dispersion by free-radically initiated aqueous emulsion polymerization of a) from 19.9 to 80 parts by weight of conjugated aliphatic dienes [monomers a)], b) from 19.9 to 80 parts by weight of vinylaromatic compounds [monomers b)], c) from 0.1 to 10 parts by weight of ethylenically unsaturated carboxylic acids and/or dicarboxylic acids [monomers c)], d) from 0 to 20 parts by weight of ethylenically unsaturated carbonitriles [monomers d)], and e) from 0 to 20 parts by weight of copolymerizable compounds other than monomers b) [monomers e)], the total amount of ethylenically unsaturated monomers a) to e) being 100 parts by weight, in the presence of water and from 0.

Abstract: Aqueous polymer dispersions which are obtainable by free radical copolymerization of (a) from 0.1 to 99.9% by weight of styrene and/or methylstyrene, (b) 0.1-99.9% by weight of 1,3-butadiene and/or isoprene and (c) from 0 to 40% by weight of other ethylenically unsaturated copolymerizable monomers, the sum of the monomers (a), (b) and (c) always being 100, in the presence of from 10 to 40% by weight, based on the monomers used, of at least one degraded starch having a molecular weight Mn of from 500 to 40 000 and of water-soluble redox catalysts are prepared by free radical copolymerization of the monomers (a), (b) and, if required, (c) in an aqueous medium in the presence of a degraded starch having a molecular weight Mn of from 500 to 10 000 and redox initiators and are used as engine sizes and surface sizes for paper.

Abstract: A process for impregnating base paper or fiber webs with an aqueous dispersion of a polymer of free-radically polymerizable compounds (monomers), which comprises from 0.1 to 5% by weight of the monomers being methacrylic acid.

Abstract: An aqueous polymer dispersion whose polymer, present in disperse distribution, is composed in free-radically polymerized form of from 20 to 65% by weight of at least one vinylaromatic monomer (monomers A), from 30 to 75% by weight of at least one monomer having two conjugated, ethylenically unsaturated double bonds (monomers B), and from 0.5 to 10% by weight of at least one other monomer, C, selected from the group consisting of &agr;,&bgr;-monoethyienically unsaturated mono- and dicarboxylic acids and amide or ester derivatives thereof and whose alkali metal ion content GA, based on the mass of the dispersed polymer, is ≧0.5% by weight, the pH of the aqueous dispersion medium being adjusted to a value below 6.

Abstract: A process for impregnating base paper or fiber webs with an aqueous dispersion of a polymer of free-radically polymerizable compounds (monomers), which comprises from 0.1 to 5% by weight of the monomers being methacrylic acid.

Abstract: The present invention provides paper coating slips comprising a low-crosslink copolymer as their binder.

Abstract: A process for selectively hydrogenating ethylenically unsaturated double bonds in polymers P involves reacting the polymers P with hydrogen in the presence of at least one hydrogenation catalyst selected from the salts and complex compounds of rhodium and/or of ruthenium in an aqueous dispersion of the polymers P that comprises not more than 20% by volume of an organic solvent. This process can be used to give hydrogenated polymer dispersions and, from these dispersions, polymers. Also claimed are aqueous polymer dispersions comprising polymers P′, which include structural units I, II and III as in claim 10, with or without structural units IV and/or V as in claim 11.

Abstract: A curved tubular flow reactor designed for carrying out chemical reactions continuously, for preparing mixtures and as a liquid-phase heat exchanger comprises a plurality of successive bends having alternating directions of curvature.

Abstract: The present invention provides paper coating slips comprising a low-crosslink copolymer as their binder.

Abstract: A polymer dispersion is prepared by free radical polymerization of an aqueous monomer emulsion by a process in which the monomer emulsion is prepared continuously at the rate of consumption.

Abstract: Leather is finished with a synthetic carboxylated rubber dispersion to which as much as 50% by weight of one or more oxides and/or hydroxides of divalent and/or trivalent metals may have been added, finishing being carried out by a process in which the carboxylated rubber dispersion is prepared by the emulsion feed method, with a conversion of more than 90%, in such a way that it contains from 20 to 60% by weight of carboxylated rubber which is soluble in dimethylformamide at room temperature.