Polarizing film for an organic electroluminescent (EL) display, a method of making the same and an organic EL display device having the polarizing film

An optical film laminate comprising:

• a continuous web of non-crystallizable thermoplastic resin substrate;
• and
• a polarizing film for an organic electroluminescent (EL) display device which is made of a polyvinyl alcohol type resin including a molecularly oriented dichroic material therein, and formed on the non-crystallizable thermoplastic resin substrate, the polarizing film for an organic EL display device being subjected to a stretching to have a thickness of 10 μm or less and satisfy the following conditions:
• T≧43.0;
• and P≧99.5, wherein T is a single layer transmittance, and P is a polarization rate.

A stretched laminate for producing an optical film laminate comprising:

• a continuous web of non-crystallizable ester type thermoplastic resin substrate, and
• a polarizing film for an organic electroluminescent (EL) display device which is made of a polyvinyl alcohol type resin including a molecularly oriented dichroic material therein, and formed on the non-crystallizable ester type thermoplastic resin substrate, the stretched laminate including a stretched intermediate product consisting of a molecularly oriented polyvinyl alcohol type resin, wherein:
• the non-crystallizable ester type thermoplastic resin substrate is made of non-crystallizable polyethylene terephthalate which is set to have an orientation function of 0.10 or less;
• and
• the stretched intermediate product is made of a polyvinyl alcohol type resin which is set to have a crystallization degree of 27% to 40% and an orientation function of 0.05 to 0.35,
• the polarizing film for an organic EL display device is formed on the non-crystallizable ester type thermoplastic resin substrate to have a thickness of 10 μm or less and satisfy the following conditions:
• T≧43.0;
• and P≧99.5, where T is a single layer transmittance, and P is a polarization rate.

A method of producing an optical film laminate wherein a polarizing film for an organic electroluminescent (EL) display device made of a polyvinyl alcohol type resin including a molecularly oriented dichroic material therein is formed on a continuous web of non-crystallizable thermoplastic resin substrate, the method comprising the steps of:

• forming a stretched laminate including a stretched intermediate product consisting of a molecularly oriented polyvinyl alcohol type resin layer by subjecting a laminate comprising the non-crystallizable thermoplastic resin substrate and a polyvinyl alcohol type resin layer formed on the non-crystallizable thermoplastic resin substrate to elevated temperature in-air stretching;
• forming a dyed laminate including a dyed intermediate product consisting of a polyvinyl alcohol type resin layer including a molecularly oriented dichroic material therein by subjecting the stretched laminate to dyeing using a dichroic material;
• and
• forming an optical film laminate including a polarizing film for an organic EL display device made of a polyvinyl alcohol type resin including a molecularly oriented dichroic material therein by subjecting the dyed laminate to in-boric-acid-solution stretching,
• wherein optical characteristics of the polarizing film for an organic EL display device represented by a single layer transmittance T and a polarization rate P are in the following ranges:
• T≧43.0;
• and P≧99.5, and a thickness of the polarizing film for an organic EL display device is 10 μm or less.

An organic electroluminescent (EL) display device comprising:

• a laminate including a first phase difference layer, and a polarizing film which is made of a polyvinyl alcohol type resin including a molecularly oriented dichroic material therein, and having a thickness of 10 μm or less and optical characteristics satisfying the following conditions:
• T≧43.0;
• and P≧99.5, wherein T is a single layer transmittance, and P is a polarization rate;
• wherein:
• a surface of the laminate on the side of the first phase difference layer is joined to one of opposite surfaces of an organic EL display panel through an optically transparent adhesive;
• a surface of the polarizing film on the side opposite to the first phase difference layer is joined to a protective layer made of a transparent resin material;
• and
• the laminate is designed to produce circularly-polarized light so as to allow light entered from a viewing side of the polarizing film.