Inventors:
James Young - Corvallis OR
Charles H. Geissel - Corvallis OR
Piotr Zenczak - Philomath OR
Assignee:
Evans Products Company - Portland OR
International Classification:
B29D 2700
Abstract:
A process of manufacturing a microporous sheet by forming a blend of a polyolefin, silica and a water insoluble plasticizer, forming a sheet from the blend, and contacting the sheet with water for a time sufficient to render the sheet microporous. The plasticizer, being essentially insoluble in water, is easily separated therefrom and recycled. The preferred plasticizers are dialkyl phthalates and dialkyl adipates having between about two and about eleven carbon atoms in the oxo-alcohol moiety.