Patent ID: 7129323

Claim:
A method of forming a polypropylene article comprising the steps of: a) providing a molten isotactic polypropylene formulation, b) introducing at least one soluble salt compound into said molten isotactic polypropylene formulation, said soluble salt compound being selected from the group consisting of: bicyclic compounds and monocycloaliphatic compounds, c) introducing a soluble organic salt into said molten isotactic polypropylene formulation, wherein said soluble organic salt comprises a C 8 –C 22 metal carboxylate; d) reacting said soluble salt compound with said soluble organic salt to form in situ an insoluble bicyclic dicarboxylate salt nucleating agent that is well dispersed and capable of providing substantial nucleation benefits to said molten isotactic polypropylene formulation; e) cooling said molten isotactic polypropylene formulation, and f) forming a polypropylene article.