Nitto-denko Corporation

Kentaro Yoshida

Minoru Miyatake

Shusaku Goto

Takeharu Kitagawa

Tomohiro Mori

Takashi Kamijo

Satoru Kunikata

A method for manufacturing a thin high-performance polarizing film includes coating a polyvinyl alcohol type resin on a resin substrate having a thickness of at least 20 &#x3bc;m and then drying the resin to thereby form a polyvinyl alcohol type resin layer, immersing thus produced polyvinyl alcohol type resin layer in a dyeing solution including a dichroic material to thereby have the dichroic material impregnated in the polyvinyl alcohol type resin layer, stretching the polyvinyl alcohol type resin layer having the dichroic material impregnated therein together with the resin substrate in a boric acid solution such that a total stretching ratio of 5.0 or more of the original length is achieved.

Thin high-performance polarizing film and method for manufacturing the same

Provided is an optical display device using a polarizing film which has a thickness of 10 &#x3bc;m or less and exhibits high optical characteristics. The optical display device comprises a continuous web of polarizing film which is made of a polyvinyl alcohol type resin having a molecularly oriented dichroic material, and formed through stretching to have a thickness of 10 &#x3bc;m or less and satisfy conditions expressed by the following formulas: P&#x3e;&#x2212;(10&#x2212;1)&#xd7;100 (where T&#x3c;42.3); and P&#x2267;99.9 (where T&#x2267;42.3), wherein T is a single layer transmittance, and P is a polarization rate. The polarizing film may be prepared by subjecting a laminate comprising a non-crystallizable ester type thermoplastic resin substrate and a polyvinyl alcohol type resin layer formed on the substrate to by 2-stage stretching consisting of preliminary in-air stretching and in-boric-acid-solution stretching.

Optical display device having polarizing film

Growing community of inventors

Ibaraki, Japan

Kentaro Yoshida