Process for the preparation of functionalised polymer particles

A process for the preparation of amine-functionalised vinyl polymer particles wherein said polymer particles have a mode particle size of at least 20 μm, which process comprises

• (a) obtaining a first particulate polymer seed material having a mode particle diameter of no more than 50 μm;
• (b) using said first seed material, performing a suspension polymerization to yield a second particulate polymer seed material having a mode particle diameter greater than that of said first seed material, and, if required, using said second seed material, performing at least one further suspension polymerization to yield a particulate polymer seed material whereby the increase in mode particle diameter in step (b) is at least ×2,
• wherein at least one of the suspension polymerizations effected in step (b) involves
• (i) forming an aqueous dispersion comprising a polymer seed material, an organic compound, a stabilizer, and a first monomer;
• (ii) allowing said organic compound and first monomer to diffuse into the seed material to produce an activated seed material;
• and
• (iii) contacting said activated seed material with a second monomer and with a polymerization initiator whilst effecting suspension polymerization thereof, and wherein in at least the final suspension polymerization of step (b) the second monomer comprises amino styrene, and at least one further vinylic monomer and said polymerisation initiator is an azo initiator.

A process for the preparation of amine-functionalised vinyl polymer particles wherein said polymer particles have a mode particle size of at least 100 μm, which process comprises

• (a) obtaining a first particulate polymer seed material having a mode particle diameter of at least 70 μm;
• (b) using said first seed material, performing a first suspension polymerization to yield a second particulate polymer seed material having a mode particle diameter greater than that of said first seed material and, if required, using said second seed material, performing at least one further suspension polymerization to yield a particulate polymer seed material having a mode size greater than 100 μm, whereby the increase in mode particle volume in step (b) is at least ×2;
• wherein
• at least one of the suspension polymerizations effected in step (b) involves
• (i) forming an aqueous dispersion comprising a polymer seed material, an organic compound, a stabilizer and a first monomer;
• (ii) allowing said organic compound and said first monomer to diffuse into the seed material to produce an activated seed material;
• and
• (iii) contacting said activated seed material with a second monomer and with a polymerization initiator whilst effecting suspension polymerization thereof,
• and wherein in at least the final polymerization of step (b) the second monomer comprises amino styrene, and at least one further vinylic monomer and said polymerisation initiator is an azo initiator.