Polarizer protective film, polarizing plate, and image display apparatus

Patent metadata

Field	Value
Publication number	US-9493684-B2
Application number	US-81193808-A
Country	US
Kind code	B2
Filing date	Nov 28, 2008
Priority date	Jan 31, 2008
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

The present invention provides a polarizer protective film excellent in optical properties (retardation and haze) and excellent in the adhesion property between a polarizer and a polarizer protective film (in particular, under high temperature and high humidity conditions). The polarizer protective film of the present invention includes a (meth)acrylic resin film and an easy-adhesion layer disposed on at least one side of the film. The easy-adhesion layer is formed from an aqueous (meth)acrylic resin dispersion.

First claim

The invention claimed is:

1. A polarizing plate, comprising
a polarizer and
a polarizer protective film,
wherein the polarizer protective film is disposed on at least one side of the polarizer,
wherein the polarizer protective film comprises a (meth)acrylic resin film and an easy-adhesion layer disposed on at least one side of the (meth)acrylic resin film,
wherein the polarizer protective film comprises the easy-adhesion layer disposed on a side facing the polarizer,
wherein the easy-adhesion layer is formed from an aqueous (meth)acrylic resin dispersion,
wherein the easy-adhesion layer is formed by applying the aqueous (meth)acrylic resin dispersion onto the (meth)acrylic resin film to form an applied layer,
wherein a resultant (meth)acrylic resin film is formed by applying the aqueous (meth)acrylic resin dispersion onto the (meth)acrylic resin film so that the easy-adhesion layer is formed directly onto the (meth)acrylic resin film,
stretching the resultant (meth)acrylic resin film in at least a uniaxial direction while subjecting the resultant (meth)acrylic resin film to a heat treatment,
and
wherein the aqueous (meth)acrylic resin dispersion comprises at least one kind of water-soluble monomer selected from the group consisting of a polyalkylene glycol (meth)acrylate, (meth)acryloyl morpholine, and a hydroxyalkyl (meth)acrylamide.

2. The polarizing plate according to claim 1 , wherein the easy-adhesion layer has a glass transition temperature of 20° C. or more.

3. The polarizing plate according to claim 1 , wherein the (meth)acrylic resin film comprises a (meth)acrylic resin having a glass transition temperature of 100° C. or more.

4. The polarizing plate according to claim 3 , wherein the polarizer protective film has an in-plane retardation Δnd of 1.0 nm or less, a thickness direction retardation Rth of 3.0 nm or less, and a haze of 1.0% or less.

5. The polarizing plate according to claim 1 , further comprising a pressure-sensitive adhesive layer.

6. An image display apparatus, comprising the polarizing plate according to claim 1 .

Assignees

• Saitou Takeshi
• Nitto Denko Corp
• Nippon Catalytic Chem Ind

Inventors

• Saitou Takeshi

Classifications

• Y10T428/1462

  Polymer derived from material having at least one acrylic or alkacrylic group or the nitrile or amide derivative thereof [e.g., acrylamide, acrylate ester, etc.] · CPC title

• C08L2201/50

  Aqueous dispersion, e.g. containing polymers with a glass transition temperature (Tg) above 20°C · CPC title

• C08L33/08

  Homopolymers or copolymers of acrylic acid esters · CPC title

• B32B2250/02

  2 layers · CPC title

• B32B27/30

  comprising vinyl {(co)polymers; comprising acrylic (co)polymers} · CPC title