Matrix amphoteric thermally regenerable ion exchange resins

A process for the preparation of an amphoteric ion exchange resin comprising acidic and basic ion exchange components wherein particles comprising a polymeric acidic ion exchange material are suspended in a liquid phase comprising a precursor material capable of being converted into a matrix of polymeric basic ion exchange material, and wherein the said precursor material which is monomeric or partially polymerized is caused to form a matrix which encapsulates the said particles characterised in that the matrix formation step is carried out in the presence of an inhibiting agent, said inhibiting agent being selected from the group consisting of a salt of a metal selected from the group of metals consisting of those defined in Groups 2A, 2B, 3A, 4A, 6B and 7B of the periodic table of elements and, a weakly basic organic material.