SOL-GEL COATINGS

SUMMARY

Sol-gel coating technology demonstrated a great potential to obtain durable coating with flexible application process. Sol-gel or « solution-gelification » process is based on the evolution from a sol to a gel state and the progressive formation of a 3D oxide coating network by hydrolysis and condensation reactions. The sol contains mainly alkoxide precursors, solvents, additives, and catalysers. By modulating these components, it is possible to offer large panels of functional properties without modification of the appearance of the substrate.

CONCEPT

Anti-contamination sol-gel properties can be managed playing on the intrinsic properties of the coating (nature of precursor, ratio, …) or on the incorporation of additives (hydrophobic, slippery agents, …)

TECHNICAL ADVANTAGE

The most important advantages of the sol-gel process are :

The good adhesion on metallic surfaces. This is due to the creation of covalent bonds between the alcoxy groups of the sol and the hydroxyls groups present at the surface of the substrate.
The low thickness of the coating inducing small modification of the surface aspect and topography.
The versality of the application process making possible application on site or in industrial chains of 3D complex shapes
The environmentally-friendly (low VOC, low temperature of curing) and the durable character (thermal and chemical stability, mechanical properties) of sol-gel films
The large panels of functional properties (anti-dirt, anti-corrosion, mechanical properties, scratch resistance, …) on various substrates (metals, polymers,...). The use of different precursors, additives,… makes this technology flexible and could combine different required functionality.

INPUT IN STELLAR

In view of the development of anticontamination and durable coating, sol-gel formulation are tailored to obtain slippery effect and omniophobic properties. Hydrophobic (fluorinated) and slippery agents as PDMS components or specific alcoxysilanes precursors are incorporated in sol-gel formulations. In parallel, work development focus on curing process with adaption of sol-gel formulation able to cure at low temperature leading to durable film.