Process for preparing emulsions of copolymers containing N- methylol or N-methylol ether groups

摘要

The process has two steps, the first consisting of polymerizing a portion of the monomer reactants in the presence of a per acid salt initiator, and at a temperature not above 60 DEG C if the N-methylol (ether) monomer is present, and the second of continuing the polymerization with the addition of the remaining monomer reactants at a temperature not above 60 DEG C and at a pH in the range of from 1 to 7, and in the presence of a redox initiator system. The process improvement resides in reducing the amount of unwanted premature condensation of the N-methylol (ether) groups during polymerization. The copolymer emulsions thereby provide thermosetting coating compositions having improved properties.