Porous polymer particles
AssigneeNOVA Chemicals (International) S.A.
InventorsMichel Florentine Jozef Berghmans, Kurt Ernest Irma Du Mong, Karel Cornelis Bleijenberg, Guy Lode Magda Maria Verbist
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Abstract
Porous polyvinylarene particles having a apparent density do of 600 to 200 kg/m3, which particles contain a nucleating agent and 2.0% by weight or less, based on the amount of polyvinylarene, of a volatile organic blowing agent. The invention also relates to a process for the preparation of these particles as well as to the use of these particles in the preparation of expanded particles and foamed articles.
Claims15
Porous polyvinylarene particles prepared from unexpanded polyvinylarene particles, said porous polyvinylarene particles having a certain pore structure and an apparent density do of 600 to 200 kg/m3, and which porous particles contain a nucleating agent and 2.0% by weight or less, based on the amount of polyvinylarene, of a volatile organic blowing agent, and which porous particles have a volume increase that is from about 1.5 to less than 3 times compared to the volume of said unexpanded particles.
Process for the preparation of porous polyvinylarene particles, in which expandable polyvinylarene particles containing a nucleating agent and from 0.5 to 4% by weight of a C2-6 organic blowing agent, based on polyvinylarene, are pre-expanded to an apparent density of 600 to 200 kg/m3 to form a certain pore structure in said porous polyvinylarene particles and which porous polyvinylarene particles contain 2.0% by weight or less of said C2-6 organic blowing agent, based on the amount of polyvinylarene.
Dependencies are inferred from the claim text.