Abstract: The invention relates to a process for the polymerization of vinyl-containing monomers such as, for example, monomeric vinyl halides, in a reaction mixture, in which process less waste is generated.

Abstract: The invention relates to a process for the polymerisation of monomeric vinyl halides in a polymerisation reactor, especially using a reflux condenser, and also to a polymerisation reactor for carrying out the process according to the invention. As a result, the space-time yield (STY) of an exothermal reaction can be substantially improved whilst the product quality remains almost the same.

Abstract: The invention relates to a process for the polymerisation of monomeric vinyl halides in a polymerisation reactor, especially using a flow-through cooler, and also to a polymerisation reactor for carrying out the process according to the invention. As a result, the space-time yield (STY) of an exothermal reaction can be substantially improved whilst the product quality remains almost the same.

Abstract: The invention relates to a process for the polymerisation of vinyl-containing monomers such as, for example, monomeric vinyl halides, in a reaction mixture, in which process less waste is generated.

Abstract: A process is described for the preparation of a polymer which contains, besides polymerized units of vinyl chloride, 30 to 60% by weight, relative to the polymer, of polymerized units of an acrylate, if appropriate together with copolymerizable monomers. The acrylate is firstly polymerized in aqueous emulsion with addition of a monomer containing at least 2 ethylenically unsaturated, non-conjugated double bonds in the presence of a fatty acid salt and in the presence of an alkane- or alkylarylsulfonate. Polymerization in aqueous suspension is then carried out in which vinyl chloride, customary polymerization auxiliaries, a precipitant for the emulsifiers used in the emulsion polymerization, and water are initially introduced, and the acrylate dispersion produced by emulsion polymerization is subsequently added. Polymers of high bulk density and good free-flowing properties which can easily be demonomerized are thus obtained.

Abstract: A sinterable, finely divided molding material and the preparation thereof are described. The molding material is composed of a vinyl chloride (graft) copolymer, at least one anionic and/or nonionic emulsifier and, if appropriate, small quantities of additives.The vinyl chloride (graft) copolymer contains 95 to 70% by weight of polymerized units of vinyl chloride, 5 to 30% by weight of polymerized units of an alkyl acrylate having 3 to 10 carbon atoms, 0 to 7% by weight of polymerized units of ethylene and 0 to 15% by weight of polymerized units of vinyl acetate.The molding material is suitable for the production of flexible, sintered moldings, in particular separator plates, for electric cells.

Abstract: The process is described for the continuous suspension polymerization of vinyl chloride in aqueous phase, in which the polymerization mixture is subjected, in 2 zones, to treatment employing different process parameters in respect of final conversion, dwell time, number of theoretical cascade stages and stirrer power applied. This procedure gives, at good space-time yields, very uniform products which have a narrow particle size distribution, a high bulk density, good flow and a low speck count. In spite of using standard kettle material, only a very low formation of deposit on the kettle walls is observed.

Abstract: In the manufacture of polymer suspensions, good spacetime yields, a narrow particle size distribution and good polymer properties are obtained in a relatively uncomplicated apparatus which includes a plurality of reactors having a length/diameter ratio of at least 4, the first reactor standing vertically and the others approximately horizontally. Plug flow of the polymerization mixture is maintained in the reaction zones provided by the reactors. In the first such zone, up to 10% of the polymerization is carried out, with agitation, preferably at a stirring energy per unit volume of 0.1 to 5 kWm.sup.-3. Wall encrustation is substantially prevented, particularly in the second reaction zone, through the use of smooth, non-metallic surfaces in the zone.

Abstract: A process for the polymerization of vinyl chloride in an aqueous phase in the presence of oil-soluble free-radical initiators and a mixture of at least two high-molecular, surface-active suspending agents is described. This mixture is composed of 10 to 90% by weight (relative to the mixture) of at least one copolymer formed from vinyl acetate and a compound of the formulaR.sub.1 --CO--NR.sub.2 --CH.dbd.CH.sub.2wherein R.sub.1 is H or alkyl having 1 to 4 C atoms and R.sub.2 is H or methyl, and of 90 to 10% by weight (relative to the mixture) of at least one cellulose ether or a partially acetylated polyvinyl alcohol. Homopolymers, copolymers or graft copolymers of vinyl chloride which have an improved combination of properties are obtained.

Abstract: Process for the manufacture of vinyl chloride polymers containing at least 50% by weight of polymerized vinyl chloride by polymerizing the monomer(s) in aqueous phase at 10 to 90.degree. C. in the presence of an oil-soluble catalyst and 0.03 to 0.4 weight % of a mixture of suspending agents containing(a) a partly acetylated polyvinyl alcohol having 5 to 25 weight % acetate units(b) at least one of the following compounds: methyl-cellulose; methyl-hydroxyethyl-cellulose; methyl-hydroxy-propyl-cellulose; hydroxyethyl-cellulose; hydroxypropyl-cellulose and(c) a partly acetylated polyvinyl alcohol having 31 to 35 weight % of acetate units.