To obtain a photocurable low refractive index polymer which has a low refractive index, good adhesivity, excellent transparency and excellent coatability, and a coating composition suitable for preventing reflection.
The low refractive index polymer comprises (a) a fluoroacryl (meth)acrylate monomer of the formula (1): CH2=C(X)COO-R-Rf (1) (X is CH3, H, F or Cl; R is a linear or branched alkylene; Rf is an alkyl containing one or more F atoms), (b) a monomer having bath imide group and an ethylenically unsaturated group represented by the formula (2) (R1 and R2 are each H or a ≤4C alkyl, or R1 and R2 are bound to each other to form a five or six- membered cyclic hydrocarbon group), and one or more other monomers (c), wherein the amounts of the monomer units (a), (b) and (c) are 20 to 99 pts.wt., 1 to 30 pts.wt., and 0 to 50 pts.wt., respectively, and which has a refractive index of ≤1.45 measured with sodium D ray at 25°C.
OKAZAKI EIICHI
IIDA AKIHITO
