Gas Barrier Coating for Packaging Materials

摘要

In the July 2010 edition of this journal a patent application was reviewed that described a coating composition with gas barrier properties derived from acid treated kaolin and dispersion polymer (PCT/WO2009114071A1). Here an alternative approach for the same application is claimed. The primary claim is for a composition that comprises a water-soluble metal silicate (>70 wt%), alumino-silicate clay and polymer dispersion. The metal silicate is preferably a lithium, sodium or potassium salt with the molar ratio of alkali metal oxide/SiO2 being around 0.25:1. In its preferred form the composition should comprise about 90% of metal silicate.