Method for manufacturing long laminated polarizing plate and long laminated polarizing plate

Abstract

It is an object of the invention to provide a method for manufacturing a long laminated polarizing plate having a long polarizing coating formed by coating directly on a long retardation film and to provide such a long laminated polarizing plate. The present invention relates to a method for manufacturing a long laminated polarizing plate comprising a long retardation film having a slow axis in its longitudinal direction and a long polarizing coating placed on the retardation film and having an absorption axis or a transmission axis in an in-plane direction at an angle of 25 to 65° to the slow axis direction of the long retardation film, the method comprising the steps: (A) preparing a long retardation film having a slow axis in its longitudinal direction and having an Nz coefficient of 1.5 or less, wherein the Nz coefficient is expressed by the formula (nx−nz)/(nx−ny), wherein nx is a maximum in-plane refractive index of the film, ny is an in-plane refractive index of the film in a direction perpendicular to the direction in which nx is obtained, and nz is a refractive index of the film in its thickness direction; (B) rubbing the long retardation film, which is obtained in the step (A), in an in-plane direction at an angle of 20 to 70° to the longitudinal direction while feeding the long retardation film; and (C) forming a coating of a liquid crystal compound solution in an isotropic phase state on the rubbed surface of the long retardation film obtained in the step (B) and solidifying the coating to form a long polarizing coating in which the liquid crystal compound is oriented.

1 . A long laminated polarizing plate, comprising:
 a long retardation film having a slow axis in its longitudinal direction; and   a long polarizing coating having an absorption axis or a transmission axis in an in-plane direction at an angle of 25 to 65° to the slow axis direction of the long retardation film, wherein   the long retardation film has an Nz coefficient of 1.5 or less, wherein the Nz coefficient is expressed by the formula (nx−nz)/(nx−ny), wherein nx is a maximum in-plane refractive index of the film, ny is an in-plane refractive index of the film in a direction perpendicular to the direction in which nx is obtained, and nz is a refractive index of the film in its thickness direction,   the long retardation film has a surface rubbed in an in-plane rubbing direction at an angle of 20 to 70° to the longitudinal direction, and   the long polarizing coating is formed by coating a solution of a liquid crystal compound in an isotropic phase state directly on the rubbed surface of the long retardation film,   the long laminated polarizing plate has an absorption axis or a transmission axis deviated by an angle of about 0°±5° from the in-plane rubbing direction.   
     
     
         2 . The long laminated polarizing plate according to  claim 1 , wherein the Nz coefficient of the long retardation film is less than 1.0. 
     
     
         3 . The long laminated polarizing plate according to  claim 1 , wherein the Nz coefficient of the long retardation film is from 0 to 0.5.