UNIAXIALLY ORIENTED BIREFRINGENT ARTICLE HAVING A STRUCTURED SURFACE

摘要

An article, such as a film, comprising a body portion and a surface portion is provided. The body portion has (i) a first and a second surface, and (ii) first and second in-plane axes that are orthogonal with respect to each other and a third axis that is mutually orthogonal to the first and second in-plane axis in a thickness direction of the body. The surface portion comprises a linear geometric feature disposed on the first surface of the body in a direction substantially parallel to the first in-plane axis of the polymeric body. The article has (i) a first index of refraction (n₁) along the first in-plane axis, (ii) a second index of refraction (n₂) along the second in-plane axis, and (iii) a third index of refraction (n₃) along the third axis, wherein n₂ and n₃ are substantially the same but substantially different from n₁; and wherein the uniaxially oriented polymeric film has a relative birefringence of 0.3 or less and wherein the ratio of the thickness of the body to the height of the geometric feature is at least 2.