Abstract: The present invention relates to agents for increasing the retention of fibres, fillers and pigments and for accelerating drainage in papermaking, and as flocculating agents in the working up of effluents from papermaking by filtration, sedimentation and flotation. They are characterized in that they contain, as active components, one or more nitrogen-containing condensation products which can be obtained by reacting (A) aliphatic polyol-ether-amines which are free from halogen groups, contain cohesive polyether segments and carry no amino groups within these segments, with (B) compounds which are polyfunctional towards amino groups, optionally in the presence of (C) polyaminopolyamides and/or (D) polyalkylenepolyamines, component (B) being employed in an amount such that water-soluble polycondensates which have a viscosity of 100 to 1,000 mPa.s at 25.degree. C. in 25% strength aqueous solution are formed.

Abstract: Use of zinc salts of mercaptobenzimidazoles corresponding to the following general formula: ##STR1## wherein R represents hydrogen or a C.sub.1 -C.sub.4 alkyl group; and/or a zinc salt of a di-C.sub.1 -C.sub.9 -alkyldithiophosphate for the preparation of nitrile rubber/PVC mixtures.

Abstract: A process for the production of rubber powder having a particle size of from about 200 to 1500 .mu. and a powdering agent content of less than 7% by weight by grinding rubber particles, wherein the rubber is initially mechanically size-reduced into surface-rich and pore-rich particles, the entire quantity of powdering agent is added to the rubber particles, which are then ground at low temperature to prevent the rubber from flowing, non-adsorbed or freshly added powdering agent is adsorbed by the rubber powder in a zone following the grinding machine, and the rubber powder obtained is cooled to such an extent that no warm flow of the rubber occurs.