Polarizing film, pressure-sensitive-adhesive-layer-attached polarizing film, method for producing polarizing film, and image display device

Patent metadata

Field	Value
Publication number	US-11079526-B2
Application number	US-201716086076-A
Country	US
Kind code	B2
Filing date	Mar 17, 2017
Priority date	Mar 28, 2016
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

A polarizing film is disclosed including a polarizer having a thickness of 10 μm or less, and a transparent resin layer on at least one surface of the polarizer,wherein the polarizer includes a polyvinyl alcohol-based resin, and has a single-body transmittance T and a polarization degree P representing optical properties satisfying the condition of the following formula:P>−(100.929T−42.4−1)×100 (provided that T<42.3) or P≥99.9 (provided that T≥42.3), andthe transparent resin layer is a formed product of a transparent resin layer forming material including a water-based emulsion resin and has a hardness of 0.01 GPa or more. The polarizing film, using a thin-polarizer, can suppress the occurrence of defects such as nano-slits and is further restrained from being lowered in optical properties in a heating and humidifying test to have a high optical reliability.

First claim

The invention claimed is:

1. A polarizing film, comprising a polarizer having a thickness of 10 μm or less, and a transparent resin layer on at least one surface of the polarizer,
wherein the polarizer comprises a polyvinyl alcohol-based resin, and is designed to have a single-body transmittance T and a polarization degree P representing optical properties satisfying the condition of the following formula:
P >−(10 0.929T−42.4 −1)×100 provided that T <42.3 or P ≥99.9 provided that T ≥42.3,

the transparent resin layer is a formed product of a transparent resin layer forming material comprising a water-based emulsion resin and has a hardness of 0.01 GPa or more, and
wherein the transparent resin layer has an indentation load of 1 to 60 μN, and the indentation load is measured by a nano-indentation method.

2. The polarizing film according to claim 1 , comprising a relaxation layer in which an alignment of the polyvinyl alcohol-based resin is partially relaxed on a side of the polarizer on which the transparent resin layer is formed.

3. The polarizing film according to claim 2 , wherein the relaxation layer has a thickness of ⅔ or less of the film thickness of the polarizer.

4. The polarizing film according to claim 2 , wherein a thickness of the relaxation layer is 0.1 μm or more.

5. The polarizing film according to claim 1 , wherein the transparent resin layer is a layer showing no pressure-sensitive adhesion properties.

6. The polarizing film according to claim 1 , further comprising a protective film.

7. A process for producing the polarizing film recited in claim 1 , comprising:
a step of applying the transparent resin layer forming material comprising a water-based emulsion resin directly onto at least one surface of the polarizer having a thickness of 10 μm or less, and
a step of drying a coating layer of the transparent resin layer forming material to form the transparent resin layer.

8. A pressure-sensitive-adhesive-layer-attached polarizing film, comprising the polarizing film recited in claim 1 , and further comprising a pressure-sensitive-adhesive layer on a transparent-resin-layer-side of the polarizing film.

9. An image display device, comprising the pressure-sensitive-adhesive-layer-attached polarizing film recited in claim 8 .

10. An image display device, comprising the polarizing film recited in claim 1 .

Assignees

• Nitto Denko Corp

Inventors

• Mita Satoshi
• Ueno Tomonori
• Xu Jingfan
• Kishi Atsushi

Classifications

• H10K59/00

  Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00 · CPC title

• G02B5/30 Primary

  Polarising elements (light-modulating devices with active elements G02F1/00) · CPC title

• G02B1/14 Primary

  Protective coatings, e.g. hard coatings · CPC title

• B32B27/00

  Layered products comprising {a layer of} synthetic resin {(fibrous or filamentary layer made of a synthetic resin B32B5/02; particulate layer made of a synthetic resin B32B5/16; foamed layer made of a synthetic resin B32B5/18)} · CPC title

• G02F1/1335

  Structural association of cells with optical devices, e.g. polarisers or reflectors · CPC title