Production of polarizing film

Abstract

Abstract PURPOSE:To obtain a dyeing system polarizing film which exhibits the polarization power equiv. to the polarization power of an iodine system by forming a melt consisting of a water soluble coating compd. contg. a specific ratio of dye and hydrophilic polymer or a soln. obtd. from a water soluble dye, hydrophilic polymer and solvent to a film and stretching this film. CONSTITUTION:The hydrophilic polymer consisting of polyvinyl alcohol or the like and the dichromatic water soluble dye contg. >=95% dye such as azo system having the polarizing power are prepd. A stock soln. for film formation is first prepd. by dissolving the water soluble polymer with water or org. solvent to prepare the soln. and adding the water soluble dye thereto in a casting method. A plasticizer such as glycols is added thereto and the soln. is cast onto a belt to form the raw film. The above-mentioned dye is impregnated in the hydrophilic polymer and pellets are formed, then the pellets are heated and kneaded and the raw film is formed by an extruder in a melt extrusion method. The raw film is uniaxially stretched in an aq. boric acid soln., by which the polarizing film having the polarization power equiv. to the polarization power of the iodine system is obtd.

Inventors

• 👤 Satoshi Mori
• 👤 Junji Toda

Bibliographic Details