| abstract |
Process of free-radical polymerization in aqueous dispersion for the preparation of polymers, employing (A) at least one ethylenically unsaturated monomer, one of which is employed as the principal monomer and is selected from styrene and its derivatives, acrylic acid and its derivatives, methacrylic acid and its derivatives, dienes, vinyl esters, vinyl ethers, vinylic pyridine derivatives, vinylsulphonic acid and its derivatives, vinylphosphonic acid and its derivatives, and N-vinyl monomers, (B) at least one free-radical initiator selected from diazo compounds, peroxides and dialkyldiphenylalkanes, (C) molecular iodine, and (D) at least one oxidizing agent whose solubility in water is at least 10 g/l, of which at least one may be the one (B); said process comprising the steps whereby (1) at least one fraction of each of compounds (A), (B), (C) and (D) is introduced into a reactor, and (2) the contents of the reactor are reacted while introducing into the reactor the remainder, where appropriate, of each of compounds (A), (B), (C) and (D). Process of free-radical polymerization in aqueous dispersion for the preparation of block copolymers starting from polymers prepared by the abovementioned process. |