3M Innovative Properties Company

Justin L Keough

Marvin E Jones

Fuming B Li

John M Sebastian

John M Brandner

Rahul R Shah

Nathan E Schultz

David A Olson

Daniel A Japuntich

Shih-Hung Chou

Rahul B Shah

Methods of preparing polymeric webs include hot melt blending of thermoplastic resins and processing aids. The process aids include hindered amine N-substituted succinimide oligomers. The webs prepared from the blends may be in the form of films or non-woven fibrous webs. Non-woven microfiber webs are useful as filtration media. Among the polymeric webs produced are electret webs. The processing aids also function as charge-enhancing additives for the electret webs.

Processing aids for olefinic webs, including electret webs

A method of making an electret article, from a polymeric article that has a zeta potential of greater than or less than &#x2212;7.5 millivolts. The article is charged by contacting it with an aqueous liquid that has a pH and conductivity as follows: (i) if the article has a zeta potential of &#x2212;7.5 mV or less, then the contacting liquid has pH greater than 7 and a conductivity of 5 to 9,000 microSiemens per centimeter; and (ii) if the article has a zeta potential of greater than &#x2212;7.5 mV, then the contacting liquid has a pH of 7 or less and a conductivity of 5 to 5,500 microSiemens per centimeter. An electret article made in this manner can provide improved electret performance, particularly in electret filtration articles.

Method of making electret articles based on zeta potential

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Vadnais Heights, MN, United States of America

Justin L Keough