A ceramic heat insulating layer formed on an iron-based base material with or without a bonding layer interposed therebetween, comprising: aggregate particles of a nepheline mineral; and a binder composed of silica particles and of a metalloxane polymer, the binder filling spaces between the aggregate...http://www.google.com.au/patents/US5962152?utm_source=gb-gplus-sharePatent US5962152 - Ceramic heat insulating layer and process for forming same
