Patent ID: 11970562

Abstract:
A phase difference film composed of a resin containing a copolymer including polymerization units A and B, the phase difference film including a cylindrical phase separation structure that generates a structural birefringence, the phase separation structure including a phase (A) having the polymerization unit A as a main component and a phase (B) having the polymerization unit B as a main component, and the phase difference film satisfying the following condition (1) or (2). Condition (1): D(A)>D(B) and f(B)>0.5, and a direction giving a maximum refractive index among in-plane directions and an orientation direction of a cylinder in the phase separation structure are parallel to each other. Condition (2): D(A)>D(B) and f(A)>0.5, and a direction giving a maximum refractive index among in-plane directions and an orientation direction of a cylinder in the phase separation structure are orthogonal to each other.