Process for the preparation of functionalised polymer particles

Abstract

A process for the preparation of amine-functionalised vinyl polymer particles which process comprises suspension polymerizing aminostyrene together with at least one other vinylic monomer and optionally a crosslinking agent.

1 - 18 . (canceled)  
   
   
       19 . 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.    
   
   
       20 . 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.    
   
   
       21 . A process as claimed in  claim 19  wherein said vinyl polymer particles are styrenic polymer particles and said vinylic monomer is a styrenic monomer.  
   
   
       22 . A process as claimed in  claim 21  wherein said styrenic monomer is styrene.  
   
   
       23 . A process as claimed in  claim 19  wherein said organic compound is a polymerisation initiator.  
   
   
       24 . A process as claimed in  claim 23  wherein said initiator is selected from the group comprising organic peroxides, peroxy esters and azo compounds.  
   
   
       25 . A process as claimed in  claim 19  wherein at least one oil-soluble inhibitor is disposed in said second monomer.  
   
   
       26 . A process as claimed in  claim 19  wherein at least one water-soluble polymerization inhibitor is present in at least one of said polymerisation steps.  
   
   
       27 . A process as claimed in  claim 19  wherein said stabiliser is a cellulose.  
   
   
       28 . A process as claimed in  claim 19  wherein seeds for a suspension polymerization stage are pre-swollen.  
   
   
       29 . A process as claimed in  claim 28  wherein seed material for a suspension polymerisation is swollen by direct addition of monomer in an amount of from 50 to 200 times the seed weight prior to effecting polymerisation.  
   
   
       30 . A process as claimed in  claim 29  wherein seeds are pre-swollen with aminostyrene, said further vinylic monomer and, optionally, a polymerization initiator.  
   
   
       31 . A process as claimed in  claim 19  wherein said aminostyrene is 4-aminostyrene.