Relationship between Molecular Orientation of Rubbed Polyimide Alignment Layer and That of Liquid-Crystalline Polymer Film Coated on the Alignment Layer

Abstract

The molecular orientation of the coating type of retardation film was investigated. The retardation film was created by photopolymerization of a liquid-crystalline (LC) monomer coated on a rubbed polyimide alignment layer. The relationship between the molecular orientation of a rubbed polyimide film and that of mesogens in a photopolymerized liquid crystal coated on the polyimide film has been investigated using optical measurements. It was found that the inclination angle of the refractive index ellipsoide and the optical retardation of photopolymerized LC films are strongly related to the optical properties of the rubbed polyimide film regardless of the rubbing conditions.

Keywords:

• alignment film
• inclination angle
• molecular orientation
• photopolymerized liquid crystal
• retardation
• rubbing treatment

ACKNOWLEDGMENTS

The authors thank Merck Chemicals Ltd., U.K. for supplying the LC monomers and Nissan Chemical Industries, Ltd., for supplying the polyimide.

Notes

^a Denier is defined as the mass grams per 9000 m. 1 Denier = 0.111 mg/m.