Siloxane coating process for metal or ceramic substrates

A method for producing a polymer-coated metal or ceramic substrate, comprising:

• (a) providing a polysiloxane liquid solution having non-linear silicon to oxygen bonding characterized by the general formula of R.sub.n SiO.sub.(4-n)/2, wherein R is a phenyl radical and n has an average value of about 0.95 to 1.05, said polysiloxane being formed by acid hydrolyzing a mono-phenyl silane monomer and condensing to form a cross-linked polyphenylsiloxane polymer having ladder-polymer heterocyclic bonding,
• (b) applying said cross-linked ladder-polymer heterocyclic polyphenylsiloxane as a liquid solution in an alcohol and water mixture to a metal or ceramic substrate, and
• (c) drying said liquid cross-linked, ladder-polymer, heterocyclic polyphenylsiloxane onto said metal or ceramic substrate at a temperature of about 75.degree. C.-110.degree. C. to forth a polysiloxane polymer-coated metal or ceramic substrate being substantially infusible above about 400.degree. C. to about 600.degree. C.