Patent ID: 7906207

Claim:
An optical film comprising, on a transparent support, at least one layer formed by a coating composition comprising a fluoro-aliphatic group-containing copolymer comprising a repeating unit A corresponding to a fluoro-aliphatic group-containing monomer, and a repeating unit B corresponding to at least one monomer, wherein each of the inorganic nature/organic nature (I/O) value(s) of said at least one monomer constituting the repeating unit B is 1.0 or less, whereby said layer is formed by coating at a coating speed of 25 m/min or more, wherein the fluoro-aliphatic group-containing copolymer comprises: (i) a repeating unit corresponding to a fluoro-aliphatic group-containing monomer represented by the following formula (1) or (5): wherein R 1 represents a hydrogen atom or a methyl group; X represents an oxygen atom, a sulfur atom or —N(R 2 )—; m represents an integer of from 1 to 6; n represents an integer of from 1 to 3; and R 2 represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, wherein, R 2 represents a hydrogen atom, halogen atom or methyl group, L 2 represents a divalent connecting group, and n represents an integer of from 1 to 6; and (ii) a repeating unit corresponding to a monomer represented by the following formula (2): wherein R 3 represents a hydrogen atom or a methyl group; Y represents a divalent linking group; and R 4 represents a cyclic alkyl group having from 1 to 20 carbon atoms, and wherein the optical film has one of the following structures (A) to (C): (A) a transparent support, a hard coat layer and a low refractive index layer provided in this order; (B) a transparent support, a hard coat layer, a high refractive index layer and a low refractive index layer provided in this order; and (C) a transparent support, a hard coat layer, a middle refractive index layer, a high refractive index layer and a low refractive index layer provided in this order, wherein the transparent support has a refractive index of from 1.4 to 1.7, and a thickness of from 30 to 150 μm, the hard coat layer has a thickness of from 0.2 to 15 μm, the low refractive index layer has a refractive index of from 1.20 to 1.49 and has a thickness of from 50 to 200 nm, the high refractive index layer has a refractive index of from 1.55 to 2.40, the middle refractive index layer has a thickness of from 30 to 500 nm and has a refractive index which is intermediate between the refractive index of the transparent support and the refractive index of the high refractive index layer, and the fluoro-aliphatic group-containing copolymer is contained in at least one of the hard coat layer, the middle refractive index layer and the high refractive index layer.