PROTECTIVE COATINGS FOR SUBSTRATES HAVING AN ACTIVE SURFACE

摘要

A coated substrate having a surface containing at least one active species such as an oxide to which is bonded at least one amorphous phospho-alumina layer containing an aluminum to phosphorus atomic ratio of about 0.2 to about 0.8 is bonded to at least one further amorphous phospho-alumina layer containing an aluminum to phosphorus atomic ratio of at least about 1.