| abstract |
Coatings compositions, which are useful as buffer layers between ceramic layers derived from polysilazane-containing compositions and ceramic layers derived from organoborosilazane polymer-containing compositions, are obtained by dissolving (A) a Group IIIa metal hydrocarbyloxide, such as aluminum sec-butoxide, (B) a Group IVb metal hydrocarbyloxide, such as zirconium propoxide, (C) a bis-, tris-, or tetrakis(dialkylamino)metal of Group IVb, such as tetrakis(diethylamino)titanium, (D) a polysilazane and/or a bis-, tris-, or tetrakis(dialkylamino)silane, such as tetrakis(dimethylamino)silane, and (E) optionally also a cyclopentadienyl Group IVb metal halide, such as bis(cyclopentadienyl)zirconium dichloride, in an organic solvent, the amounts of ingredients A-D being such that each constitutes 1-50% of their combined weights, and the amount of ingredient E being such that it constitutes 0-20% of the combined weights of the ingredients. |