Vesiculated polymer beads
AssigneeImperial Chemical Industries PLC
InventorsNeil Perrins, Mary E. Kelly
Life of this patent
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Abstract
Vesiculated polymer beads are prepared in which a water-in-oil-in-water emulsion containing a cross-linkable polymer and a copolymerizable monomer in the oil phase is heated in the presence of an initiator to cure the polymer beads, wherein curing is commenced in a first stage in the presence of a substantially water-insoluble initiator and, when the beads are sufficiently stable, curing is completed in a second stage in the presence of an at least partially water-soluble initiator. Preferably, the completion of curing is carried out at a temperature higher than that of the first stage. The beads can be used in low odor paint formulations.
Claims12
In a process for producing vesiculated polymer beads in which a water-in-oil emulsion containing a crosslinkable polymer and a copolymerisable monomer in the oil phase is heated in the presence of an initiator to cure the polymer beads, the improvement in the process comprising:
- crosslinking the polymer and the copolymerisable monomer by addition copolymerization, where the polymer is a partially ethylenically unsaturated polyester resin and the monomer is unsaturated monomer, by (a) commencing curing in a first stage by a substantially water insoluble perester initiator and, when the beads are sufficiently stable, (b) completing the curing in a second stage in the presence of at a partially water soluble initiator selected from a peroxide or a peracid, and at a temperature higher than the first stage curing.
Dependencies are inferred from the claim text.