Method for producing polarizing film

Patent metadata

Field	Value
Publication number	US-10088705-B2
Application number	US-201515515885-A
Country	US
Kind code	B2
Filing date	Sep 29, 2015
Priority date	Sep 30, 2014
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A method for producing a polarizing film includes (1) preparing a laminate (a) which includes a carrier film and a polarizer with a thickness of 10 μm or less formed on one surface of the carrier film and contains a polyvinyl alcohol-based resin; (2) peeling off the carrier film from the laminate (a); and (3) applying a liquid material to a side of the laminate (a) from which the carrier film has been peeled off and then solidifying or curing the liquid material to form a transparent resin layer with a thickness of 0.2 μm or more, wherein the liquid material contains a resin component or a curable component capable of forming a resin layer. This production method enables the achievement of a polarizing film which is able to have satisfactory durability in a heated environment even in cases where a thin polarizer is used therefor.

First claim

The invention claimed is:

1. A method for producing a polarizing film, the method comprising:
providing a laminate comprising a carrier film and a polarizer,
wherein the polarizer has a thickness of up to 10 μm,
wherein the polarizer is formed on one surface of the carrier film and the polarizer comprises a polyvinyl alcohol-based resin;
peeling off the carrier film from the laminate; and then
applying a liquid material to a side of the polarizer from which the carrier film has been peeled off and then
solidifying the liquid material to form a transparent resin layer with a thickness of 0.2 μm or more,
wherein the liquid material contains a resin component dissolved or dispersed in water.

2. The method for producing a polarizing film according to claim 1 , wherein the transparent resin layer has an 80° C. compressive elastic modulus of 0.1 GPa or more.

3. The method for producing a polarizing film according to claim 1 , wherein the liquid material is an aqueous solution containing a polyvinyl alcohol-based resin.

4. The method for producing a polarizing film according to claim 1 , wherein the liquid material has a viscosity of up to 1,000 mPa·s at 25° C.

5. The method for producing a polarizing film according to claim 1 , wherein in the providing step, the laminate is obtained by performing at least a stretching step and a dyeing step.

6. The method for producing a polarizing film according claim 1 , further comprising forming a protective film on a polarizer side of the laminate,
wherein the polarizing film is a one-side-protected polarizing film having the protective film provided on only one side of the polarizer.

7. The method for producing a polarizing film according to claim 1 , wherein the polarizer 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).

8. The method for producing a polarizing film according to claim 1 , further comprising forming a pressure-sensitive adhesive layer on a side of the transparent resin layer.

9. The method for producing a polarizing film according to claim 1 , further comprising:
forming a protective film on a polarizer side of the laminate, and
forming a pressure-sensitive adhesive layer on a side of the transparent resin layer,
wherein the polarizing film produced is a one-side-protected polarizing film having the protective film provided on only one side of the polarizer.

10. The method for producing a polarizing film according to claim 1 , wherein the carrier film is a thermoplastic resin film and has a thickness of 20 to 200 μm.

11. The method for producing a polarizing film according to claim 1 , wherein the polarizer has a thickness of 2 μm to 8 μm.

12. The method for producing a polarizing film according to claim 6 , wherein the protective film is selected from the group consisting of polyester-based polymers, cellulose-based polymers, acryl-based polymers, styrene-based polymers, and polycarbonate-based polymers.

Assignees

• Nitto Denko Corp

Inventors

• Miyai Emi
• Ikeshima kentaro
• Omine Toshiki
• Mita Satoshi
• Kishi Atsushi
• Ueno Tomonori

Classifications

• G02F2413/10

  with refractive index ellipsoid inclined, or tilted, relative to the LC-layer surface O plate · CPC title

• G02B5/3033 Primary

  in the form of a thin sheet or foil, e.g. Polaroid · CPC title

• B23B37/00

  Boring by making use of vibrations of ultrasonic frequency (working materials by subjecting the grinding tools or the abrading medium to vibration, e.g. grinding with ultrasonic frequency, B24B1/04) · CPC title

• G02B1/11

  Anti-reflection coatings · CPC title

• B23B27/00

  Tools for turning or boring machines (for drilling machines B23B51/00); Tools of a similar kind in general; Accessories therefor · CPC title