摘要 |
The extrusion of polymeric materials, especially thermoplastic polymeric materials, requires a number of physical attributes in the polymer to be controlled during extrusion to effect desirable surface characteristics on the extruded polymer. Extrusion additives have been provided for the improvement of these attributes and characteristics. The present invention describes an additive system for extrudable thermoplastic polymers, extrudable polymer compositions containing the additive system, and extrusion processes using polymers containing the additive system of this invention. The extrusion additive of the present invention comprises: (i) a fluorocarbon polymer, (ii) a poly(oxyalkylene) polymer, (iii) magnesium oxide, and (iv) optionally a stabilizer. The extrudable composition of the invention comprises: (A) an extrudable polymer (e.g., a predominant amount, such as at least 50 % by weight of solids), and (B) an effective amount of the stabilized processing aid (extrusion additive).
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