Cortec Corporation (St. Paul, MN) earned U.S. Patent 7,588,820 for packaging films to inhibit corrosion in packaged goods that include nanoclays, polymers and vapor phase corrosion inhibitor (VCI) materials. The three types of materials were blended to produce masterbatches with final compositions of 1-2% VCI chemicals and 2-10% nano-clay particles. The films prepared from the blended material showed improved physical properties. The films have both vapor phase corrosion inhibiting characteristics as well as corrosion agent barrier characteristics.
Nano-clay particles dispersed in polymeric substrate resins, such as polyethylene resin, are available commercially under the trade name "Nanoblend 2001", from Poly-One Corporation of Avon Lake, Ohio. The Nanoblend 2001 material is preferably blended with a polymeric substrate resin such as polyethylene to produce a mixture having between about 2 and 10% by weight nano-clay particles. Nano-clay particles mixed with polymeric resins are also available from other commercial sources.
The packaging film may be formed as a multiple layer co-extruded film, wherein a first polymeric layer is disposed between a second polymeric layer including nano-clay particles, and a third polymeric layer including one or more corrosion inhibitor materials, according to inventors Robert Berg, Arthur H. Ahlbrecht, Margarita Kharshan, and Boris A Miksie. VCI materials vaporize from the film into the enclosed package to minimize corrosion caused by any moisture entering into or contained within the enclosure. The film is formed through a single-step process. Such a one-step formation operation may be performed in a blown film extruder. The market for all types of flexible packaging materials is expected to exceed $26 billion in 2010.