3m Innovative Properties Company

Steven John Pachuta

Marvin E Jones

Seth M Kirk

Gerald R Spartz

William J Schultz

Peter D Condo

Wendy L Thompson

Vivian Wynne Jones

Alan D Rousseau

Chad A Haraldson

John S Huberty

Mary I Buckett

Douglas P Goetz

William P Klinzing

Patrick J Sager

Andrew W Chen

Mark McCormick

Hyacinth L Cabibil

Mark Mccormick

A method of making a fluorinated fibrous web, which method includes providing a nonwoven webthat contains polymeric fibers, creating a plasma that contains fluorine atoms at a first location, and contacting the nonwoven web with products from the plasma at a second locationremote from the first location. The method avoids exposure of the web to the plasma and hence expands the manufacturing processing window. Webs so fluorinated have a different CFHto CFratio when compared to locally fluorinated webs having similar levels of surface fluorination. The remote fluorinated webs can be subsequently charged electrically to provide a good performing electret filtersuitable for use in an air purifying respirator. Webs fluorinated in accordance with this invention also may exhibit good performance even after being 'aged' at high temperatures.

Remote fluorination of fibrous filter webs

Compositions comprising surface-modified calcite nanoparticles dispersed in a curable resin and to coatings and fibrous composites incorporating such compositions are described. The nanocalcite particles have a high magnesium to calcium surface concentration ratio. The surface-modifying agents include a binding group ionically associated with the nanoparticles, and a compatiblizing segment compatible with the curable resin. The surface-modifying agent may also include a reactive group capable of reacting with the curable resin. Methods of preparing nanocalcite composites, and coatings and fibrous composites prepared from such nanocalcite composites are also described.

High magnesium surface concentration nanocalcite composites

An electret article that includes a polymeric material that has electric charge imparted thereto, that has one or more heteroatoms, that has a fluorosaturation ratio of less than 200, and that has an atomic percent fluorine of greater than about 40%. The inventive electret article is resistant to charge degradation upon exposure to high temperatures for prolonged time periods.

Electret article having heteroatoms and low fluorosaturation ratio

An electret article that includes a polymeric material that has electric charge imparted thereto, that has a CF:CFratio of at least 0.15 and that has a fluorosaturation ratio greater than about 200. The electret article may be in the form of a porous web of polymeric fibers suitable for use as a filter. The inventive electret article is resistant to charge degradation upon exposure to high temperatures for prolonged time periods.

Electret article having high fluorosaturation ratio

A method and apparatus are provided for the analysis of buried layers of an analyte material by: a) removing surface layers of said analyte material with an atomic force microscopy (AFM) stylus to expose a buried layer; and b) analyzing a buried layer, preferably for molecular structure. An apparatus is provided which encompasses both AFM and one or more additional surface analytical apparati within a controlled atmosphere under coordinated computer control.

Method and apparatus for molecular analysis of buried layers

Growing community of inventors

Eagan, MN, United States of America

Steven John Pachuta