ALTANA

ACTEGA Rhenania:

Barrier Coatings for Plastic Packaging

ACTEGA Rhenania (Grevenbroich), a subsidiary of ACTEGA Coatings & Sealants, together with the former subsidiary of Rembrandtin (Vienna), has developed an improved solution for plastic packaging. The problem is that synthetic packaging materials still let through too many gases such as oxygen or carbon dioxide, which can cause anything from impaired flavor to health risks.

This permeability restricts the use of plastic packaging with such commodities as high-quality fruit juices, readymade sauces or beer. So that the advantages of such packaging can still be exploited, it is essential to reduce the permeability of the material.

First approach:

- has been to develop a cationic, UV-hardening binder system, which effectively impedes the entry of gas molecules. With this new type of nano-composite system, which serves as a barrier coating, the permeability of the packaging is reduced to a hundredth of its original value.

Second approach:

- has been to exploit the knowledge that super thin SiO2 layers can be applied to plastic surfaces using a plasma process designed to drastically reduce the gas permeability. Thanks to recent findings made in silane chemistry, ACTEGA Rhenania and Rembrandtin have succeeded in manufacturing SiO2 coatings that have good barrier effects comparable with those demonstrated by the prototype of the plasma process - and, through a combination of both processes, permeability has been halved again.

Both approaches have already been successfully subjected to a series of tests and have been registered since Oktober 2003 with the German Patent and Trade Marks Office.