Evonik Rohm Gmbh

Evonik Roehm Gmbh

Rohm Gmbh

Norbert Hoffmann

Steffen Krill

Johannes Vorholz

Andreas Weber

Marcus Denger

Christian Meier

Alpertunga Kueksal

Pamela Boehmann

Klaus Albrecht

Marcel Treskow

Andreas Klosendorf

Nikolaos Papadopoulos

Reiner Mueller

Mona Rueppel

Dominic Stoerkle

Michael Schnabel

Melanie Jungkamp

Pamela Bohmann

Alpertunga Kuksal

Dominic Storkle

Mona Ruppel

Reiner Muller

Isabelle Klein

Mona RÜPPEL

Dominic STÖRKLE

Reiner MÜLLER

Pamela Böhmann

Alpertunga Küksal

The present invention relates to a continuous or semi-continuous freeze coagulation process for aqueous polymer dispersions, wherein said process comprises a freezing step and a solid-liquid separation step and is further characterized in that it comprises the further step of admixing water and/or water vapor between the freezing step and the solid-liquid separation step.

Continuous or semi-continuous freezing coagulation method for aqueous polymer dispersions

The invention relates to a process for preparing a (meth)acrylate copolymer containing tertiary amino groups by free-radical polymerization in solution from a monomer mixture selected from a) 30 to 70% by weight of a C-C-alkyl ester of acrylic acid or methacrylic acid and b) 70 to 30% by weight of an alkyl ester of acrylic acid or methacrylic acid with a tertiary amino group in the alkyl radical and c) 0 to 10% of further copolymerizable vinyl monomers, whereby one or more polymerization initiators, optionally one or more molecular weight regulators and one or more solvents or of a solvent mixture are added to the monomer mixture to give a polymerization mixture, which is polymerized at temperatures from 30 to 120&#xb0; C. over a period of 2 to 24 hours, where the polymerization mixture is finally polymerized to give a polymerization syrup with a conversion of the monomers to the copolymer of at least 99% by weight, where the polymerization syrup is subsequently degassed by distillation or by extrusion and the degassed polymerization syrup is further comminuted to a copolymer preparation in the form of a granulate or powder, where the copolymer preparation is characterized by a molecular weight (M) of 25.000 to 75.000 g/mol a polydispersity index of 2.1 to 2.9 and a residual solvent concentration of less than 1.000 ppm by weight.

Process for preparing a (meth)acrylate copolymer containing tertiary amino groups by free-radical polymerization in solution

The invention relates to a process for preparing a (meth)acrylate copolymer containing quaternary ammonium groups from a monomer mixture selected from: (a) 80 to 99% by weight of a C1-C4-alkyl ester of acrylic acid or methacrylic acid; and (b) 20 to 1% by weight of an alkyl ester of acrylic acid or methacrylic acid with a quaternary ammonium group in the alkyl radical; and (c) 0 to 10% of further copolymerizable vinyl monomers whereby one or more polymerization initiators, optionally one or more molecular weight regulators and one or more solvents or of a solvent mixture are added to the monomer mixture to give a polymerization mixture, which is polymerized at temperatures from 30 to 120 C over a period of 2 to 24 hours, where the polymerization mixture is polymerized to a polymerization syrup with a conversion of the monomers to the copolymer of at least 99% by weight, where the polymerization syrup is subsequently degassed by distillation or by extrusion and the degassed polymerization syrup is further comminuted to a copolymer preparation in the form of a granulate or powder and where the copolymer preparation is characterized by a molecular weight (Mw) of 25.000 to 50.000, a polydispersity index of 2.0 to 3.0 and a residual solvent concentration of less than 10.000 ppm by weight.

Process for preparing a (meth)acrylate copolymer containing quaternary ammonium groups by free-radical polymerization in solution

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Griesheim, Germany

Norbert Hoffmann