Coating solution for forming composite metal oxide film and process for making same

A process for producing a coating composition for forming a composite metal oxide film comprising the steps of:

• reacting component(s) (A) with component (B) then subsequently
• incorporating component(s) (C) therein, and then subsequently
• adding component (D) therein;
• wherein,
• component (A) is at least one member selected from the group consisting of a reaction product, a partial hydrolyzate of said reaction product, and a partial acylated product of said reaction product wherein said reaction product is obtained by a reaction between at least one compound containing a carbonyl group and at least one metal compound represented by formula (I):
• M.sub.1 A.sub.n (I)
• wherein M.sub.1 is Ti, Zr, Nb, Hf or Ta;
• A is -OR or a halogen atom, R is a saturated or unsaturated hydrocarbon having 1-6 carbon atoms;
• and n is an integer of 2-5,
• component (B) is a polyhydric alcohol compound,
• component (C) is at least one metal compound selected from the group consisting of formulas (II), (III) and (IV);
• wherein,
• formula (II) is a metal carboxylate compound represented by:
• M.sub.2 (OCOR).sub.m (II)
• wherein M.sub.2 is Pb, Sr, Ba, Mg, Zn, La, Y or Li;
• R is a saturated or unsaturated hydrocarbon having 1-6 carbon atoms;
• and m is an integer of 1-4;
• formula (III) is a metal nitrate compound represented by:
• M.sub.2 (NO.sub.3).sub.m (III)
• wherein M.sub.2 is Pb, Sr, Ba, Mg, Zn, La, Y or Li;
• and m is an integer of 1-4;
• and
• formula (IV) is a metal nitrite compound represented by:
• M.sub.3 (NO.sub.2).sub.l (IV)
• wherein M.sub.3 is Sr, Ba or Li;
• and l is an integer of 1 or 2, and
• component (D) is an alcohol soluble polymer.