Introduction
Plastic materials are well known as poorly wettable materials, mainly due to the lack of polar functional groups on the surface, with subsequent problems of adhesion failures of functional layers such as inks, adhesives and varnishes.

To improve wettability and therefore adhesion, several physical treatments such as flame, corona or plasma, are usually applied on the surface, with a final effect of introducing polar groups and enhancing surface energy.

However, these treatments are not stable and the resulting surface modification is uneven, showing variations during printing or coating processes. Moreover the improved adhesion of the functional layers is due to a purely physical interaction or to the formation of weak bonds. For these reasons, adhesion is weak and has low thermal and chemical resistance.

Ciba Specialty Chemicals has developed Ciba® Prime IT™, an innovative, patented technology to improve adhesion of UV-curable inks *, coatings and adhesives on plastics.

UV printing technologies allow high printing qualities to be achieved without the use of solvents and with very low energy consumption. However, adhesion of UV inks on plastics is sometimes poor, making it necessary to use physical or chemical treatments (as primers). Compared to Prime IT™ other chemical treatments require higher quantities and additional procedures, involving for example the use of solvents and/or less environmentally compatible chemicals.

*Water-based inks can also be used.

For further details contact us at primeit@cibasc.com