Heat stabilizers containing hydrotalcite particles with specific zeta potentials that demonstrate improved processing and performance in molded vinyl compounds

摘要

Particulate solid heat stabilizer compositions for vinyl halide polymers are provided having about 30% to 90% by weight hydrotalcite particles represented by a sigmoidal curve on a cartesian coordinate plot of zeta potential (mV) versus pH. The curve has negative zeta potential values balanced against positive zeta potential values over a pH range and an inflection point between a pH of about 3 about 6 representing the isoelectric point (IEP) between said negative and positive zeta potential values. The stabilizer compositions are essentially free flowing, storage stable, and processable upon mixing components of the composition for blending with a vinyl halide polymer in effective amounts to confer heat stabilizing effectiveness upon said polymer.