| abstract |
The reaction between (a) a polymerisate of acrylamide and/or methacrylamide and optionally of one or more further types of polymerizable ethylenic-unsaturated monomers, (b) formaldehyde, (c) a secondary amine and (d) a functional derivative of an acid having stabilizing properties against further polymerization of (a) and containing in the functional radical at least one NH group capable of entering into equilibrium reaction with formaldehyde under the reaction conditions used, e.g. urea, under neutral or basic conditions and in certain molar ratios, produces products, which in free base, acid addition salt or quaternary ammonium salt form are useful as flocculation agents, and particularly as retention aids for paper manufacture. |