Technical and Industrial Aspects of Corrosion Protection with Sol-gel Coatings

摘要

Organic-inorganic hybrid polymers can be used as binders for coating materials.Silicon alkoxides are hydrolysed to achieve a stable colloidal sol.In this sol the colloidal particles have average diameters in a range of about 40 - 50 manometers.When used as anticorrosive coatings they can be applied on different metals.One coating material is tailored for the protection of aluminium.Hardening is carried out by thermal curing.The coating shows excellent adhesion and corrosion protection directly on aluminium without chromating having a dry thickness of 4-8 mum(clear coating)and about 5-15 mum when pigmented.A second coating material can be used on mild steel.This one is an airdrying 2-pack material with a solid content of 100%.With a coating thickness of 30-40 microns it exhibits a very good corrosion resistance.It can be used industrially as a sinlge coating or it can be used as primer with conventional topcoats.Additionally the coatings can have anti-adhesive properties which allow to prepare surfaces with easy-to-clean or anti-graffiti properties.Samples for industrial use will be presented.