One-side-protected polarizing film, pressure-sensitive-adhesive-layer-attached polarizing film, image display device, and method for continuously producing same

Patent metadata

Field	Value
Publication number	US-10094954-B2
Application number	US-201515515385-A
Country	US
Kind code	B2
Filing date	Sep 29, 2015
Priority date	Sep 30, 2014
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

The present invention pertains to a one-side-protected polarizing film having a transparent protective film on only one surface of a polarizer, wherein: the polarizer contains a polyvinyl alcohol-based resin, has a thickness of 10 μm or less, 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>−(100.929T−42.4−1)×100 (provided that T<42.3) or P≥99.9 (provided that T≥42.3); and the other surface of the polarizer has a transparent layer having a compressive elastic modulus at 80° C. of 0.1 GPa or more. Even when the polarizer has prescribed optical properties and the thickness is 10 μm or less, this one-side-protected polarizing film is capable of suppressing the occurrence of through cracks and nano-slits.

First claim

The invention claimed is:

1. A one-side-protected polarizing film, comprising:
a polarizer;
a transparent protective film provided on only one surface of the polarizer; and
a transparent layer provided directly on another surface of the polarizer, wherein
the polarizer comprises a polyvinyl alcohol-based resin, has a thickness of 10 μm or less, 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), and
the transparent layer has an 80° C. compressive elastic modulus of 0.1 GPa or more.

2. The one-side-protected polarizing film according to claim 1 , wherein the transparent layer is a product formed from a resin material.

3. The one-side-protected polarizing film according to claim 1 , wherein the transparent layer has a thickness of less than 3 μm.

4. The one-side-protected polarizing film according to claim 1 , wherein the polarizer contains 25% by weight or less of boric acid based on the total weight of the polarizer.

5. A pressure-sensitive-adhesive-layer-attached polarizing film comprising: the one-side-protected polarizing film according to claim 1 ; and a pressure-sensitive adhesive layer.

6. The pressure-sensitive-adhesive-layer-attached polarizing film according to claim 5 , wherein the pressure-sensitive adhesive layer is provided on the transparent layer of the one-side-protected polarizing film.

7. The pressure-sensitive-adhesive-layer-attached polarizing film according to claim 5 , wherein the pressure-sensitive adhesive layer is provided on the transparent protective film of the one-side-protected polarizing film.

8. The pressure-sensitive-adhesive-layer-attached polarizing film according to claim 5 , further comprising a separator provided on the pressure-sensitive adhesive layer.

9. The pressure-sensitive-adhesive-layer-attached polarizing film according to claim 8 , which is in the form of a roll.

10. An image display device comprising the one-side-protected polarizing film according to claim 1 .

11. A method for continuously producing an image display device, the method comprising the steps of:
unwinding the pressure-sensitive-adhesive-layer-attached polarizing film from the roll of the pressure-sensitive-adhesive-layer-attached polarizing film according to claim 9 ;
feeding the pressure-sensitive-adhesive-layer-attached polarizing film with the separator; and
continuously bonding the pressure-sensitive-adhesive-layer-attached polarizing film to a surface of an image display panel with the pressure-sensitive adhesive layer interposed therebetween.

12. An image display device comprising the pressure-sensitive-adhesive-attached polarizing film according to claim 5 .

13. A method for producing the one-side-protected polarizing film according to claim 1 , comprising:
the polarizer;
the transparent protective film provided on only one surface of the polarizer; and
the transparent layer provided directly on another surface of the polarizer, wherein
the polarizer comprises a polyvinyl alcohol-based resin, has a thickness of 10 μm or less, 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 layer has an 80° C. compressive elastic modulus of 0.1 GPa or more, and
the transparent layer is provided by applying directly a transparent layer-forming material on another surface of the polarizer.

Assignees

• Nitto Denko Corp

Inventors

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

Classifications

• G02B1/14 Primary

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

• C09J7/29

  Laminated material (metallised plastics C09J7/22) · CPC title

• C09J2201/622

  Chemistry & Metallurgy · mapped topic

• C09J2203/326

  for bonding electronic components such as wafers, chips or semiconductors · CPC title

• C09J2201/606

  Chemistry & Metallurgy · mapped topic