Organic EL display device

Patent metadata

Field	Value
Publication number	US-9285525-B2
Application number	US-201514689837-A
Country	US
Kind code	B2
Filing date	Apr 17, 2015
Priority date	Mar 15, 2012
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

An organic EL display device including a substrate, a transparent electrode, a luminescent layer, and a metal electrode layer in this order from a light emission side, a circularly polarizing plate disposed on the light emission side of the substrate, the circularly polarizing plate including a polarizing film and phase difference films that stacked on each other. The phase difference film includes a resin composition (A) containing polystyrene-based polymer having a syndiotactic structure and polyarylene ether, a ratio of the polystyrene-based polymer having the syndiotactic structure with respect to the polyarylene ether in the resin composition (A) is 65:35 to 55:45, being a weight ratio of (the polystyrene-based polymer having the syndiotactic structure) with respect to (the polyarylene ether), the phase difference film satisfies a relation Re 450 <Re 550 <Re 650 , and an Nz coefficient of the phase difference film at a wavelength of 550 nm is −0.25 to −0.05.

First claim

The invention claimed is:

1. A phase difference film, comprising:
a layer formed of a resin composition (A) containing a polystyrene-based polymer having a syndiotactic structure and polyarylene ether,
wherein:
a ratio of the polystyrene-based polymer having the syndiotactic structure with respect to the polyarylene ether in the resin composition (A) is 65:35 to 55:45, the ratio being a weight ratio of (the polystyrene-based polymer having the syndiotactic structure) with respect to (the polyarylene ether),
the phase difference film satisfies a relation Re 450 <Re 550 <Re 650 , and
Re 450 , Re 550 , and Re 650 are in-plane direction retardations of the phase difference film at measurement wavelengths of 450 nm, 550 nm, and 650 nm, respectively.

2. The phase difference film according to claim 1 , wherein Re 450 /Re 550 in the phase difference film is 0.80 or more and 0.90 or less.

3. The phase difference film according to claim 1 , wherein a birefringence Δn (Δn=nx−ny) of the phase difference film at a wavelength of 550 nm is 0.0020 or more and 0.0050 or less.

4. The phase difference film according to claim 1 , having a thickness of 80 μm or less.

5. The phase difference film according to claim 1 , wherein the polyarylene ether contains a polymer including a phenylene ether unit.

6. The phase difference film according to claim 1 , wherein the in-plane direction retardation Re 550 of the phase difference film at a measurement wavelength of 550 nm is 110 nm to 150 nm.

7. The phase difference film according to claim 1 , wherein the phase difference film is prepared by subjecting a long-length pre-stretch film formed of the resin composition (A) to stretching in a direction within a range of 40° or more and 50° or less with respect to a lengthwise direction of the long-length pre-stretch film.

8. The phase difference film according to claim 7 , wherein the stretching is performed at a temperature equal to or higher than (Tg−15)° C. and equal to or lower than (Tg+1)° C., wherein (Tg) is the glass transition temperature of the resin composition (A).

9. The phase difference film according to claim 1 , wherein the phase difference film is prepared by subjecting a long-length pre-stretch film layered body to stretching in a direction within a range of 40° or more and 50° or less with respect to a lengthwise direction of the long-length pre-stretch film layered body, the pre-stretch film layered body including a P1 layer formed of the resin composition (A) and a P2 layer provided in contact with the P1 layer and formed of a thermoplastic resin (B).

10. The phase difference film according to claim 9 wherein the thermoplastic resin (B) is at least one selected from acrylic resins, resins containing alicyclic structure-containing polymers, and polycarbonate resins.

11. The phase difference film according to claim 10 , wherein the long-length pre-stretch film layered body is obtained by co-extrusion or co-flow casting of the resin composition (A) and the thermoplastic resin (B).

12. The phase difference film according to claim 9 , wherein the long-length pre-stretch film layered body is obtained by co-extrusion or co-flow casting of the resin composition (A) and the thermoplastic resin (B).

13. The phase difference film according to claim 9 , wherein the stretching is performed at a temperature equal to or higher than (Tg−15)° C. and equal to or lower than (Tg+1)° C., wherein (Tg) is the glass transition temperature of the resin composition (A).

14. The phase difference film according to claim 1 , wherein the phase difference film is prepared by: subjecting a long-length pre-stretch film layered body to stretching in a direction within a range of 40° or more and 50° or less with respect to a lengthwise direction of the long-length pre-stretch film layered body, the pre-stretch film layered body including a P1 layer formed of the resin composition (A) and a P2 layer provided in contact with the P1 layer and formed of a thermoplastic resin (B), whereby a phase difference film layered body including a p1 layer formed by stretching the P1 layer and a p2 layer formed by stretching the P2 layer is obtained; and then removing the p2 layer.

15. The phase difference film according to claim 14 , wherein the thermoplastic resin (B) is at least one selected from acrylic resins, resins containing alicyclic structure-containing polymers, and polycarbonate resins.

16. The phase difference film according to claim 14 , wherein the long-length pre-stretch film layered body is obtained by co-extrusion or co-flow casting of the resin composition (A) and the thermoplastic resin (B).

17. The phase difference film according to claim 14 , wherein the stretching is performed at a temperature equal to or higher than (Tg−15)° C. and equal to or lower than (Tg+1)° C., wherein (Tg) is the glass transition temperature of the resin composition (A).

18. The phase difference film according to claim 1 , wherein:
an Nz coefficient of the phase difference film at a wavelength of 550 nm is −0.25 to −0.05,
the Nz coefficient represents (nx−nz)/(nx−ny),
nx represents a refractive index in a direction of an in-plane slow axis of the phase difference film,
ny represents a refractive index in a direction of an in-plane fast axis of the phase difference film, and
nz represents a refractive index in a thickness direction of the phase difference film.

Assignees

• Zeon Corp

Inventors

• Kinohira Tomokazu
• Fujii Kohei
• Morita Takashi
• Yamanaka Shunsuke
• Hatano Taku

Classifications

• G02B5/3025 Primary

  Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state (G02B5/3008, G02B5/3016 take precedence) · CPC title

• G02B5/3083 Primary

  Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001) · CPC title

• H10K59/8791

  Arrangements for improving contrast, e.g. preventing reflection of ambient light · CPC title

• H01L25/048

  Electricity · mapped topic

• H01L27/3232

  Electricity · mapped topic