Composition for forming hardcoat layer, hardcoat film, article and image display device having hardcoat film, and method for manufacturing hardcoat film

A composition for forming a hardcoat layer, comprising:

• a polyorganosilsesquioxane;
• and
• a polymerization initiator,
• wherein the polyorganosilsesquioxane has, at least, a siloxane constitutional unit containing an oxetanyl group and a siloxane constitutional unit containing an epoxy group and is represented by the following General Formula (1),
• wherein, in the General Formula (1), Ra represents a group containing an oxetanyl group;
• Rb represents a group containing an epoxy group;
• Rc represents a monovalent substituent;
• Ra, Rb, and Rc each have a structure including none of an amide bond, a urea bond, and a urethane bond;
• p and q represent an integer equal to or greater than 1;
• r represents an integer equal to or greater than 0;
• p/q is equal to or greater than 1.0 and less than 99;
• in a case where each of p, q, and r is an integer equal to or greater than 2, a plurality of Ra's may be the same as or different from each other, a plurality of Rb's may be the same as or different from each other, and a plurality of Rc's may be the same as or different from each other;
• and in a case where r is an integer equal to or greater than 2, a plurality of Rc's may form a bond with each other.