Compositions and their cured forms, molded forms, sheet-shaped forms, and optical waveguides

Abstract

This invention provides a composition capable of forming a hardened material exhibiting high refractive index and excellent resistance to yellowing. This invention provides a composition comprising compound (A) of formula (II) and compound (B) of formula (B). [In formula (II), L1x represents a single bond or a divalent group. A1x represents an oxygen atom or a sulfur atom. At least one of the two A1x atoms is a sulfur atom. mx represents 0 or 1. nx represents any integer from 0 to 6. R1x represents a monovalent substituent. R2x represents a hydrogen atom or a monovalent substituent.] [In formula (B), Rb1, Rb2, Rb3, and Rb4 each independently represent a monovalent hydrocarbon group. X- represents a halide ion.]