Coated polymeric particles having improved anti-block characteristics, method of making such particles, and apparatus therefor
AssigneeEquistar Chemicals, LP
InventorsDavid O. Bostrom, William K. Shumake, Paul H. Jackson
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Abstract
To provide superior anti-agglomeration, or tackiness-reducing, properties, one aspect of the invention is directed to coated polymeric particles, with each of the coated particles comprised of a polymeric substrate particle and a block-reducing coating on the surface of the substrate particle. The coating includes polymeric coating particles which advantageously may be in the form of a micro-fine powder. Also disclosed herein is a process for applying the polymeric coating particles onto the polymeric substrate particles, as well as equipment which is especially useful in producing the coated polymeric particles.
Claims25
A method of making a coated polymeric particle having improved anti-block characteristics, comprising the step of:
- contacting a polymeric substrate particle with an aqueous coating composition,
- the polymeric substrate particle comprising a polymeric material, and the aqueous coating composition comprising a block-reducing coating having polymeric coating particles,
- the polymeric material and the polymeric coating particles being from the same chemical family.
A method of making a coated polymeric particle having improved anti-block characteristics, comprising the steps of:
- introducing a substrate particle into the interior space of a chamber having an interior space and an interior sidewall;
- rotating a screw within the interior space, the screw including a shaft having at least one radially extending helical flight, the helical flight having a crest;
- spraying an aqueous coating composition into the interior space from at least one of a first spray head and a second spray head, each of which is in fluid communication with the interior space, the first spray head including a discharge nozzle including an orifice, with the orifice being substantially flush with the interior sidewall of the chamber;
- and
- contacting the substrate particle with the aqueous coating composition in the interior space, thereby forming a coated polymeric particle.
Dependencies are inferred from the claim text.