Optical body, optical film adhesive body, and method for manufacturing optical body

An optical body, comprising:

• an optical film provided with a first concave-convex structure formed on one surface of the optical film, and a second concave-convex structure formed on an other surface of the optical film;
• and
• a master film that covers the first concave-convex structure, wherein
• an average period of concavities and convexities of the first concave-convex structure is less than or equal to visible light wavelengths, and
• the master film is provided with a third concave-convex structure which is formed on a surface that faces the first concave-convex structure, and which has a reverse shape of the first concave-convex structure,
• wherein the optical film and the master film are separable from each other at an interface between the first concave-convex structure and the third concave-convex structure by virtue of a following condition applying:
• (a) an elastic modulus of the optical film is different from an elastic modulus of the master film, and the elastic modulus of the optical film is from 300 MPa to 700 MPa, and the elastic modulus of the master film is from 700 MPa to 1500 MPa, and
• wherein an aspect ratio of the second concave-convex structure is smaller than an aspect ratio of the first concave-convex structure,
• the aspect ratio of the first concave-convex structure is a ratio of a height of convexities constituting the first concave-convex structure and a diameter of a bottom face of concavities constituting the first concave-convex structure, and
• the aspect ratio of the second concave-convex structure is a ratio of a height of convexities constituting the second concave-convex structure and a diameter of a bottom face of concavities constituting the second concave-convex structure.