Acetal-protected silanol group-containing polysiloxane composition

A coating composition or a photosensitive composition comprising:

• a polysiloxane obtained from a hydrolysis-condensation product of a hydrolyzable silane having 2 to 4 hydrolyzable groups in a molecule by protecting silanol groups of the condensation product with acetal groups, wherein
• acetal protection of the silanol groups is carried out using a vinyl ether of Formula (3)
• in Formula (3), R1a, R2a, and R1a each are a hydrogen atom or a C1-10 alkyl group;
• R4a is a C1-10 alkyl group;
• and R2a and R4a optionally form a ring by bonding to each other, and
• the hydrolyzable silane consists of at least one hydrolysable silane of Formula (1):
• R1aSi(R2)4-a Formula (1)
• in Formula (1), R1 is an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, or an organic group having an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, or a cyano group and is bonded to a silicon atom through a Si—C bond;
• R2 is an alkoxy group, an acyloxy group, or a halogen group;
• and a is an integer of 0 to 3 wherein the hydrolysis condensation product, an organic group bonded to the silicon atoms through Si—C bonds exists in a molar ratio of 0≤the organic group)/(Si)≤0.29 on average.