Coating composition for the production of insulating thin films

A coating composition for use in producing an insulating thin film, comprising:

• (A) at least one silica precursor selected from the group consisting of the following silica precursors (A-1) and (A-2):
• a silica precursor (A-1) comprised of at least one compound selected from the group consisting of an alkoxysilane represented by the following formula (1) and a hydrolysis product thereof:
• R1nSi(OR2)4-n (1)
• wherein each R1 independently represents a hydrogen atom, a straight chain or branched alkyl group having 1 to 6 carbon atoms, a vinyl group or a phenyl group, each R2 independently represents a straight chain or branched alkyl group having 1 to 6 carbon atoms and n represents an integer of from 0 to 3;
• and
• a silica precursor (A-2) comprised of at least one compound selected from the group consisting of an alkoxysilane represented by the following formula (2) and a hydrolysis product thereof:
• R3m(R4O)3-mSi—(R7)p—Si(OR5)3-qR6q (2)
• wherein each R3 independently represents a hydrogen atom, a straight chain or branched alkyl group having 1 to 6 carbon atoms, a vinyl group or a phenyl group, each R4 independently represents a straight chain or branched alkyl group having 1 to 6 carbon atoms, each R5 independently represents a straight chain or branched alkyl group having 1 to 6 carbon atoms, each R6 independently represents a hydrogen atom, a straight chain or branched alkyl group having 1 to 6 carbon atoms, a vinyl group or a phenyl group, R7 represents an oxygen atom, a phenylene group or a group represented by the formula:
• —(CH2)r— wherein r represents an integer of from 1 to 6, each of m and q independently represents an integer of from 0 to 2, and p represents 0 or 1;
• (B) at least one organic polymer;
• (C) water;
• (D) at least one alcohol;
• (F) phosphoric acid;
• and optionally
• (E) an organic solvent for a mixture of said components (A), (B), (C), (D) and (F);
• wherein the weight ratio (WR) of said water (C) to said at least one silica precursor (A) satisfies the formula 0.01<WR<10, and the weight of said water (C) is larger than that of said at least one alcohol (D),
• with the proviso that when said at least one organic polymer (B) is insoluble in a mixture of said water (C) and said alcohol (D), said coating composition comprises all of said components (A), (B), (C), (D), (F) and (E).