Free radical miniemulsion polymerization with low shear and heat exchanger
AssigneeBASF SE
InventorsKlemens Mathauer, Hubertus Kroner, Andreas Keller, Walter Kastenhuber
Life of this patent
Estimating the term…
Abstract
A process for preparing an aqueous polymer dispersion by free-radical polymerization of compounds I and II whose individual solubility in water is very different by the miniemulsion polymerization technique, in which process the reaction mixture is agitated by an external circuit which leads from and back again to the reaction vessel and comprises at least one low-shear pump and at least one heat exchanger having an essentially laminar flow profile. The copolymers prepared in accordance with the invention can be produced in a good yield within short times and exhibit good performance properties.
Claims6
A process for preparing an aqueous polymer dispersion by free-radically initiated polymerization of free-radically polymerizable compounds I whose individual solubility in water under the conditions (pressure, temperature) of the free-radically initiated polymerization is .gtoreq.0.001% by weight and whose polymer particles also comprise further compounds II whose solubility in water under the conditions of the free-radically initiated polymerization is .ltoreq.0.001% by weight, in which process a) at least one compound I and at least one compound II are admixed used to prepare an oil-in-water miniemulsion (emulsion I) whose disperse phase consists essentially of droplets having a diameter .ltoreq.500 nm and b) at least a portion of the emulsion I is supplied continuously, as feed stream I to a reaction vessel in the course of continuing free-radical polymerization, wherein the reaction mixture is agitated by an external circuit which leads from and back to the reaction vessel and which comprises at least one low-shear pump and at least one heat exchanger having an essentially laminar flow profile.
Dependencies are inferred from the claim text.