Semi-continuous process for the production of copolymers

摘要

Preparing copolymer, comprises (a) preparing copolymer in a semicontinuous process in a polymerization device, adding acid monomers and radical polymerization initiator into polymerization reactor, and reacting acid monomers and polyether macromonomers in the composition under the formation of copolymers through radical polymerization, and (b) preparing copolymer in a semicontinuous process, storing polyether macromonomers, acid monomers, water and/or obtained aqueous reaction composition in polymerization container, and adding acid monomers in the polymerization containers. Preparation of a copolymer, comprises (a) preparing the copolymer in a semicontinuous process manner in a polymerization device comprising a polymerization reactor connected with a dosing device, storing acid monomers in the dosing device and/or polyether macromonomers, acid monomers and water in the polymerization reactor, adding acid monomers from the dosing device into the polymerization reactor, adding radical polymerization initiator in the polymerization reactor before and/or during dosing of the acid monomers in the polymerization reactor, so that an aqueous reaction composition exists in the polymerization reactor, and reacting the acid monomers and polyether macromonomers in the reaction composition under the formation of copolymers through radical polymerization, where the molar ratio of the totally used acid monomer and totally used polyether macromonomers is 20:1-1: 1, the molar ratio of acid monomer present in the polymerization reactor and the acid monomer added in the polymerization reactor is 10:1-1:10, the polymerization reactor is emptied after completion of the addition of acid monomers and after the reaction of 70 mole% of the stored polyether macromonomers, and the partial quantity of the aqueous reaction composition present in the polymerization reactor is detected; and (b) preparing the copolymer in a semicontinuous process manner, storing the polyether macromonomers, acid monomers, water and/or the obtained partial quantity of the aqueous reaction composition in the polymerization container, adding the acid monomers in the polymerization containers during and/or after the addition of radical polymerization initiators, where the ratio of the obtained partial quantity of the aqueous reaction composition present in the polymerization container to the total quantity of the water used in the second process stage, the acid monomers used in the second process stage and the polyether macromonomers used in the second process stage is 0.05-30 wt.%. An independent claim is included for the copolymer obtained by the above process.