Polymerizable composition comprising silsesquioxane compound having acrylic group

A polymerizable composition comprising:

• (a) 100 parts by mass of reactive silsesquioxane compound as a polycondensate of an alkoxy silicon compound A of Formula [1] with an alkoxy silicon compound B of Formula [2] in an amount by mole of 0 to 99 times the amount of the alkoxy silicon compound:
• R1—Si(OR2)3 [1]
• where R1 is a C1-10 alkyl group having at least one (meth)acryloyloxy group and R2 is a methyl group or an ethyl group,
• R3—Si(OR4)3 [2]
• where R3 is a C1-10 alkyl group, a C7-10 aralkyl group, or a C6-14 aryl group and R4 is a methyl group or an ethyl group;
• (b) 10 to 2,000 parts by mass of fluorene compound of Formula [3]:
• where R5 and R6 are each independently a hydrogen atom or a methyl group, L1 and L2 are each independently a phenylene group optionally having a substituent or a naphthalenediyl group optionally having a substituent, L3 and L4 are each independently a C1-6 alkylene group, and m and n are 0 or a positive integer with m+n satisfying 0 to 40;
• and
• (c) a chain transfer agent in an amount of 0.01 to 10 parts by mass relative to 100 parts by mass of the total amount of the components (a) and (b).