Process for the preparation of polymer particles
AssigneeNOVA Chemicals (International) S.A.
InventorsHugo Angela Albert Berghmans, Igor Chorvath, Peter Kelemen, Eric Wilhelmus Johannes Frederik Neijman, Johannes Maria Zijderveld
Life of this patent
Estimating the term…
Abstract
The present invention provides a process for preparing an expandable polymer of a vinyl aromatic monomer and a polar water adsorbing monomer. The monomers are partially polymerized and then suspended in water so that the resulting beads contain from 3 to 40 weight % water which act as the sole or a predominant blowing agent.
Claims9
Process for the preparation of polymer particles containing the polymer of a vinylarene monomer and having an average particle diameter of 0.1 to 6 mm, which process comprises:
- a) mixing a polar polymer capable of absorbing at least 0.5 g of water per gram dry polar polymer, with a vinylarene monomer;
- b) pre-polymerising the vinylarene monomer in the mixture thus obtained to a polymerisation degree of 15 to 50% to obtain a pre-polymerised mass;
- c) suspending the pre-polymerised mass into an aqueous medium to yield suspended particles;
- and
- d) polymerising the suspended particles to complete monomer conversion.
Polymer particles containing a polymer of a vinylarene monomer, a polar polymer capable of absorbing at least 0.5 g of water per gram dry polar polymer, and water, which polymer particles contain from more than 3 to 40% water, based on amount of vinylarene and have an average particle diameter of 0.1 to 6 mm.
Dependencies are inferred from the claim text.