Additives for Polymers September 1991

TECHNICAL NOTES

System for incorporating Eastman Chemical Co., Kingsport, Term., (USA) has developed a additives without new method for coating additives on to the surface of reactor extrusion granules, flake, or pellets of polyolefmes, polystyrene, ABS, compounding - 1 polycarbonate, and possibly other polymers. The company has a

line of Aquastab products, which include a wide range of standard commercial additives - liquid and solid - dispersed at 25-50% loadings into a low-molecular-weight polyolefm wax; then the latter is emulsified in water. These emulsions are sprayed onto polymer pellets or granules, which are then dried, leaving an additive coating that adheres firmly and withstands airveying, shipping and storage. This eliminates the heat history and capital cost of extrusion compounding, and offers a nondusting way to provide a wide range of formulations from a single base-resin composition.

Plast. Tech., 1991, 37, (June), 15

System for incorporating The new XANTRIX additive delivery system developed by additives without Himont Inc., Wilmington, DE, (USA) is intended to overcome a extrusion particular limitation of single-screw extrusion compounding, that compounding - 2 of screw slippage which occurs when using liquid additives at

concentrations above 5-7%. The XANTRIX system allows up to 30% by weight of liquid or low-melting additives to be incorporated, as well as up to 100/o of higher-melting solids. These additives are uniformly distributed throughout a spherical polypropylene homopolymer which serves as a carrier, and said to be suitable for the majority of applications. A different carrier can be used if justified by market demand.

Among the additives currently incorporated by this system are: peroxides, acid neutralizers, antifogging agents, antimicrobials, antioxidants, antistatic agents, fragrances, nucleants, oils, slip agents, and UV absorbers. Himont is currently working on the inclusion of liquid fire retardants.

Plast. Tech, 1991, 37, (July), 17, 19

Branched versions of highly-filled PBT

GE Plastics has introduced new developmental branched versions of highly-filled “heavy” VALOX PBT. It is branched in a secondary process through the presence of an unidentified polymer - possibly a thermoset system - that links integrally with the polymer backbone forming a “trifunctional species.”

While the “heavy” VALOX remains crystalline, the branching creates a tougher material with increased melt strength for blow moulding, extrusion and thermoforming applications. Prior to this branching, the material was primarily limited to injection moulding.

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Plaat. Tech, 1991, 37, (June)), 71

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