Résumé : |
Unlike the setting process, film drying and curing are controlled mainly by chemically reactive coating additives and curing agents. The most important groups of additives controllinq chemical processes during film formation are driers, initiators, and catalysts, with the function to initiate or accelerate drying and curing reactions. Photoinitiators provide clear and not heavily pigmented coatings and thin layers of inks with ability for curing when subjected to a sufficient UV radiation. Crosslinkers constitute a group of specific curing agents for controlled chemical post-cure, that allows significant improvement in service properties for coatinqs based on thermoplastic polymers. Water scavengers, and anti-skinning agents can be also attributed to the reactive-type additives to control film forming processes. |