Abstract: [Object] To provide a coating composition excellent in coatability and free from viscosity increase caused by degradation over time, and also to provide a hardened film-formation method employing that. [Means] The present invention provides a coating composition comprising: a siloxane resin having silanol groups or alkoxysilyl groups, and a polyol having hydroxyl groups at both ends of a straight 2 to 5 carbon atom hydrocarbon chain. This coating composition enables to form a hardened film of high transparency, of high insulation and of low dielectricity.

Abstract: A positive photosensitive siloxane composition containing: a polysiloxane (Ia), which is obtained by hydrolyzing and condensing the silane compound represented by RSi(OR1)3 in general formula (1) and the silane compound represented by Si(OR1)4 in general formula (2) in the presence of a basic catalyst, and a pre-baked film of which has a dissolution rate of 1,000 ?/second or less in a 5 wt % TMAH aqueous solution; a polysiloxane (Ib), which is obtained by hydrolyzing and condensing at least the silane compound represented by general formula (1) in the presence of an acid or basic catalyst, and a pre-baked film of which has a dissolution rate of 100 ?/second or more in a 2.38 wt % TMAH aqueous solution; and a diazonaphthoquinone derivative and solvent.