摘要:
An aromatic polycarbonate composition having less than 400 parts per billion each of ionic impurities, particularly sulfate, chloride and fluoride ions prepared by devolatilizing the ionic impurities from a polycarbonate composition employing an aqueous medium of about 1% by weight based on the weight of the polycarbonate composition. Preferably the devolatilizing is carried out in an extruder during compounding the polycarbonate composition and preferably under a vacuum. Also, the extruded strands of polycarbonate resin are quenched in a deionized water bath.
摘要:
A multi-layered sealable film and method of storing and transporting a role of the film without buckling or starring, the film comprising a core layer comprising polypropylene sandwiched between at least a first and (optionally) second tie-layer on either side of the core; a sealable layer with two sides, one side adhered to the first tie-layer; wherein at least the first tie-layer comprising a blend of polypropylene and within the range of from 5 wt % to 40 wt % of a soft polymer additive, preferably a propylene-α-olefin elastomer having within the range of from 10 wt % to 30 wt % α-olefin derived units, wherein the blend is preferably partially or completely immiscible. A roll of the inventive films can be readily stored and transported without loss due to film defects.
摘要:
The efficiency of a redistribution catalyst during polycarbonate redistribution is improved by employing an extruder screw design that provides a melt seal between the extruder throat and the vacuum port. A melt seal exists when the free volume within the extruder is sufficiently filled with molten resin so as to prevent the passage of gases between sections of the extruder.