The most common classes of organic coatings include:
Furthermore, such coatings can be applied by means of various techniques, in dependance to the nature of the coating, the dimension and characteristic of the components to be coated, and productivity constrains:
liquid spray (air/airless, electrostatic);
powder electrostatic spray and fluidized beds;
extrusion coating (e.g. in the coatings of pipes);
laminated films adhesive coatings;
electro-painting (e.g. in automotive priming);
other techniques (e.g. roll, brush, dip, spinning,..).
The most important properties of organic coatings are mainly related to selected combinations of resin binders and pigments.
One of the main concerns in R&D is the formulation of new environmental-friendly solutions, able to comply with the new regulations for health and environmental protection (e.g. VOC limitation directives, RoHS directive, etc.).
Research activities are mainly focused on binders (e.g. reduction of solvent volume in the liquid paints, development of solventless radiation curable resins, substitution of chlorine/fluorine containing resin) and pigments (e.g., elimination of heavy metals in corrosion inhibitive and colour pigments).
At the same time new developments are in progress in order to improve the coating durability and to add new functionalities to the coated surfaces (e.g. scratch resistance, self-repairing properties, pollution reducing activity, easy-to-clean or anti-graffiti properties, perlescent or photochromic effects…).
The corrosion protection and the aesthetic aspects are, in fact, expected to keep on being one of the main driving concerns for what regards organic coatings applications. Many of these functionalities can be obtained by means of the new opportunities offered by the nanotechnology.