Abstract: A triazine ring-containing polymer having a high refractive index and a low birefringence, and being capable of being subjected to injection molding, wherein the polymer having a repeating unit of *-[A-B-]-*, including a structural unit A derived from a triazinedithiol compound, and a structural unit B including an aromatic hydrocarbon group; and a thermoplastic resin, a thermoplastic article, and an optical part including the polymer.

Abstract: The di(meth)acrylate compound of the present disclosure is represented by the following formula (1): wherein Z1a and Z1b each represent an arene ring, R1a and R1b each represent a substituent, k1 and k2 each denote an integer of not less than 0, m1 and m2 each denote an integer of 0 to 4, and at least one of m1 and m2 denotes 1 or more, R2a and R2b each represent a substituent, n1 and n2 each denote an integer of 0 to 4, m1+n1 and m2+n2 each denote 4 or less, A1a and A1b each represent a straight- or branched-chain alkylene group, A2a and A2b each represent a straight- or branched-chain alkylene group, p1 and p2 each denote an integer of not less than 0, and R3a and R3b each represent a hydrogen atom or a methyl group. The di(meth)acrylate compound is a novel compound having a high refractive index.

Abstract: Provided are a retardation film that has a high heat resistance, has excellent formability and handleability even in a single-layer structure, has a negative thickness-direction retardation Rth value, and is suitable as a negative A-plate or a positive C-plate and a method for producing the film. The retardation film is formed of a stretched film of a polyester resin, contains a unit (A1) represented by the formula (1) as a diol unit (A) and a unit (B1) represented by the formula (2a) or (2b) as a dicarboxylic acid unit (B), and is a negative A-plate or a positive C-plate. In the formulae, Z1 and Z2 represent an aromatic hydrocarbon ring, R1, R2a, R2b, R3a and R3b represent a substituent, k, p1 and p2 denotes an integer of 0 to 8, q denotes an integer of 0 to 4, m1, m2, n1 and n2 denotes an integer of not less than 0, A1a and A1b represents an alkylene group, and A2a, A2b and A3 represents a divalent hydrocarbon group.