| abstract |
Preparation of water-soluble, amino group-containing condensation or addition product with an increased dewatering and retention effect when used in the production of paper, comprises: (a) subjecting aqueous solutions of the condensation or addition products listed below, to an ultrafiltration step using membranes in order to separate 5 - 95 wt.% of the products as a permeate, and optionally (b) recovering the amino-group containing water-soluble products with enhanced dewatering and retention properties from the retentate. The condensate and addition reaction products are selected from: (a) reaction products of alkylene diamines, polyalkylene polyamines and/or ethylene imine-grafted polyamidoamines with cross-linking agents (CLAs) containing \- 2 functional groups ; (b) Michael reaction addition products of alkylene diamines, polyalkylene polyamines and/or ethylene imine-grafted polyamidoamines, or monoethylenic unsaturated carboxylic acids or their salts, esters, amides or nitriles with at least bifunctional CLAs; (c) amidised polyethylene imines (prepared by reacting polyethylene imines with monobasic carboxylic acids or their esters, anhydrides or amides), optionally reacted with CLAs containing \- 2 functional groups; (d) polyethylene imines, quaternary polyethylene imines, (cross-linked) phosphono-methylated polyethylene imines and/or carboxymethylated (by chain extension reaction) polyethylene imines, or (e) cross-linked alkoxylated polyethylene imines, cross-linked quat. polyethylene imines, cross-linked phosphono-methylated polyethylene imines and/or carboxymethylated (by chain extension reaction) polyethylene imines. |