Skim coat for making a durable hard coating on substrates, e.g. crucibles for melt-processing silicon, comprises silicon nitride particles and a binder consisting of solid nano-particles made by a sol-gel process

摘要

A skim coat (I) for producing a durable hard coating (II) on a substrate, comprising (a) silicon nitride particles and (b) a binder comprising solid nano-particles and/or precursors thereof made by a sol-gel process. Independent claims are included for (1) formed products (III) comprising a substrate with a hard coating (II) as above (2) a method for the production of (III) by coating the substrate once or more with (I) (by doctor blade, dip-coating, flooding, spin-coating, spraying, brushing or painting) and then hardening the skim coat (I) .