Lead Acid Battery Separator With Improved Electrical And Mechanical Properties
May 1, 2007
Patented is an oxidation-resistant, microporous polyolefin web with high-strength mechanical and low electrical resistance properties. The web features a solid matrix including an ultrahigh molecular weight polyolefin component and a friable, highly dispersing, precipitated silica component. The ultrahigh molecular weight polyolefin component has a molecular weight that provides sufficient molecular chain entanglement to form a microporous web with high-strength mechanical properties. The silica component is comprised of weakly bonded silica aggregates wherein the bonds between the silica aggregates are broken down in response to shear forces imparted during material processing to form predominately discrete individual porous silica aggregates that are mutually separate from one another and dispersed throughout the microporous web to maintain a low operational electrical resistance in the presence of an electrolyte.