摘要 |
Certain thermoplastic additives (combinations of clarifying and nucleating compounds) that induce simultaneously low clarity and high nucleation efficacy are provided. Such additives include combinations of certain bicyclic salts (which by themselves induce very high nucleation efficacy) and thermoplastic clarifying agents, including certain dibenzylidene sorbitol acetals and derivatives (hereinafter collectively referred to as "DBSs")(which alone provide very low haze measurements and thus highly desirable clarity characteristics). In comparison, other types of standard thermoplastic nucleators, such as sodium benzoate and sodium 2,2'-methylene-bis-(4,6-di-tert-butylphenyl) phosphate provide relatively high peak crystallization temperatures, but do not combine synergistically with clarifiers, such as DBSs, to provide the same results as for the inventive combination of bicyclic salts and DBSs. Thermoplastic compositions as well as thermoplastic additive packages comprising such inventive nucleator compounds, as well as methods of producing polypropylene compositions and articles made therefrom, are also contemplated within this invention.
|