초록 ▼

The preparation of polymers free from emulsifiers and protective colloids by the free-radical initiated emulsion polymerization of ethylenically unsaturated co-polymerizable monomers, wherein the emulsion polymerization is carried out in the absence of emulsifiers and protective colloids, using wate

The preparation of polymers free from emulsifiers and protective colloids by the free-radical initiated emulsion polymerization of ethylenically unsaturated co-polymerizable monomers, wherein the emulsion polymerization is carried out in the absence of emulsifiers and protective colloids, using water-soluble, free-radical forming initiators and with the addition, at least at the start of the polymerization, of at least 0.01% by weight, based on the total amount of monomers, of poly-(ethylenically unsaturated) monomers, and the polymers can be obtained in the form of aqueous or non-aqueous dispersions or in the form of powder. The use of the polymers in the form of dispersions or powders for modifying polymer materials and polymer raw materials and for the production of shaped articles and films.

대표청구항 ▼

A process for preparing a polymer (in powder form or dispersed in water-miscible, inert organic medium free from emulsifier and protective colloid) by free-radical-initiated emulsion copolymerization of poly-(ethylenically unsaturated) and mono-(ethylenically unsaturated) copolymerizable monomers, w

A process for preparing a polymer (in powder form or dispersed in water-miscible, inert organic medium free from emulsifier and protective colloid) by free-radical-initiated emulsion copolymerization of poly-(ethylenically unsaturated) and mono-(ethylenically unsaturated) copolymerizable monomers, which comprises: first subjecting to preliminary polymerization (in a polymerization mixture which is free from acyclic olefin with conjugated double bonds, from emulsifier and from protective colloid, which has a pH of from 1 to 5 and one or more water-soluble, free-radical-forming initiators, as well as a dispersing medium which is water or an aqueous solution containing at least one water-miscible inert organic compound) an amount which is at least 0.01% by weight (based on the total amount of monomers) of poly-(ethylenically unsaturated) monomer by itself or together with a partial amount of mono-(ethylenically unsaturated) monomer, then metering into the polymerization mixture the remaining amount of the mono-(ethylenically unsaturated) monomer or the latter amount together with any remaining amount of the poly-(ethylenically unsaturated) monomer and any remaining amount of initiator, thereafter completing polymerization of the resulting mixture at an acid pH to obtain a polymer dispersion, additionally adding a water-soluble, inert organic compound to the polymerization mixture during or after polymerization, and subsequently, after completion of the polymerization, (a) freeing the thus-obtained dispersion partly or completely from its water content by distillation or (b) eliminating the dispersing medium from the polymer dispersion to obtain the polymer in powder form.