MULTI-LAYERED LAMINATES OF MICROPOROUS FILMS

摘要

A multi-layer, microporous polyolefin sheet is provided with at least two microporous polyolefin layers autogenously bonded together to have the same porosity as prior to bonding. The sheet material is formed by blending a polyolefin with an additive which separates on cooling, extracting the additive from each layer with a solvent after cooling and drying the layers in contact to effect bonding. As compared to previous laminated products, the product does not have altered porosity at the interface nor contamination with bonding agents.