Wacker Chemie Ag

Bernhard Eckl

Hans-Peter Weitzel

Muhammad Babar

Wolf-Dieter Hergeth

Jessica Seidel

Mehmet Guenaltay

Wilhelm Kaiser

Michael Kalchauer

Eric Frauendorfer

The invention relates to a method for producing polymer powder compositions which are redispersible in water and which are based on polymerisates of one or more ethylenically unsaturated monomers. In a first step, an aqueous polymerisate dispersion is produced by means of a radically initiated polymerization of one or more ethylenically unsaturated monomers in an aqueous medium, said polymerisate dispersion being convened into the polymer powder composition which is redispersible in water by means of a diving process. The invention is characterized in that the polymerization and the drying process are each carried out in a continuous manner, and the polymerization and the diving process are carried out in separate interconnected modules.

Continuous and modular process for producing water-redispersible polymer powder compositions

The present disclosure relates to a process and/or method for producing a polymer dispersion by free-radically initiated emulsion polymerization of radically polymerizable ethylenically unsaturated monomers within a polymerization reactor. The polymer dispersion obtained is transferred to a post-treatment reactor and is post-treated therein. The polymer dispersion within the post-treatment reactor is conveyed, simultaneously to the post-treatment, to a circuit for filtration and analysis and is then subsequently fed back into the post-treatment reactor.

Method for preparing a polymer dispersion

Higher throughput in aqueous addition polymerization is made possible by use of an external shell and tube heat exchanger operated in reverse mode, with coolant flowing through the tubes and polymerization mixture flowing through the shell around the tubes.

Method for polymerization with external cooling

Subjects of the invention are processes for preparing vinyl acetate-ethylene copolymers in the form of their aqueous dispersions or water-redispersible powders by means of radically initiated emulsion polymerization and optional subsequent drying of the resultant polymer dispersions, characterized in that the emulsion polymerization of vinyl acetate, ethylene and optionally one or more further ethylenically unsaturated monomers is carried out in the presence of one or more protective colloids in one or more Taylor reactors.

Process for preparing vinyl acetate-ethylene copolymers by emulsion polymerization

A method for processing wastewater and exhaust gas condensates from the polymerization of vinyl acetate and ethylene and optionally other comonomers in an aqueous medium by suspension or emulsion polymerization employs relieving pressure after completion of the polymerization of the polymerization batch and discharging the polymer dispersion. During the relieving, the gaseous phase is removed by means of a compressor. Optionally, the gaseous phase occurring during stripping is removed by the compressor and cooled by one or more heat exchangers before entry into the compressor. The liquid phases occurring in the compressor and optionally in the heat exchanger are separated from the gaseous phase and the liquid phases are given to a rectification column, and separated into a vinyl acetate monomer phase and a wastewater phase, and the vinyl acetate monomer phase is resupplied to polymerization.

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Burghausen, Germany

Bernhard Eckl