abstract |
An invert microlatex of at least one cationic water-soluble vinyl monomer, if necessary copolymerized with at least one anionic or non-anionic water-soluble vinyl monomer, is prepared by a process consisting in a first stage (a) of preparation of an invert microemulsion (of the water-in-oil type) and a second stage (b) in which the invert microemulsion obtained in stage (a) is subjected to conditions of polymerization, stage (a) consisting in mixing: (A) an aqueous solution of at least one cationic water-soluble vinyl monomer, if necessary mixed with at least one anionic or non-ionic water-soluble vinyl monomer, (B) an oil phase containing at least one liquid hydrocarbon, and (C) at least one non-ionic surface active agent, in a proportion sufficient to obtain an invert microemulsion, and having an HLB, either between 11 and 15 when the cationic water-soluble vinyl monomer is alone or mixed with an anionic water-soluble vinyl monomer, or between 7.5 and 13 when the cationic water-soluble vinyl monomer is mixed with a non-ionic water-soluble vinyl monomer. Application as a flotation and drainage additive, and as an absorber and retainer of water. |