Polarization plate, liquid crystal display device and protective film
Provided are a polarization plate which has a high mechanical strength, which does not impair a visibility even under a high temperature and high humidity, which is excellent in flexibility and abrasion resistance, and which reduces a visible disturbance such as color unevenness due to a size change, as well as a liquid crystal display device using the polarization plate. A film composed of a plurality of layers composed mainly of thermoplastic resins is used as a first protection film used for a visible side of the polarization plate, and at least one surface layer of this first protection film is composed mainly of an acrylic resin. Furthermore, a second protection film having a specific property is disposed at a side of a liquid crystal cell.
1. A protection film comprising an intermediate layer containing a thermoplastic resin 1 , a surface layer 2 containing a thermoplastic resin 2 laminated on a surface of said intermediate layer, and a surface layer 3 containing a thermoplastic resin 3 laminated on the other surface of said intermediate layer,
either one or both of said surface layer 2 and said surface layer 3 being composed of an acrylic resin having a glass transition temperature (Tg) of 100° C. or higher,
said intermediate layer containing an ultraviolet light absorber,
one or more of said intermediate layer, said surface layer 2 and said surface layer 3 containing elastic particles, and
wherein the thickness of either one or both of said surface layer 2 and said surface layer 3 is 10 μm or more.
2. The protection film according to claim 1 , wherein said elastic particles are contained in said surface layer 2 and/or said surface layer 3 .
3. The protection film according to claim 1 , wherein, amoung said surface layers 2 and 3 , at least one surface layer which is opposite to an object to be protected is composed of said acrylic resin having the glass transition temperature (Tg) of 100° C. or higher.
4. The protection film according to claim 1 , wherein the thickness of said intermediate layer is 10 to 40 μm.
5. The protection film according to claim 1 , wherein the total number of laminated layers of said protection film is 7 or less.
6. The protection film according to claim 1 , wherein the moisture permeability of said protection film is 10 g/m 2 ·24 hours or more and 200 g/m 2 ·24 hours or less.
7. The protection film according to claim 1 , wherein said protection film is obtained by coextrusion.
8. The protection film according to claim 1 , wherein the thermoplastic resin 1 is a polymethylmethacrylate resin, an alicyclic olefin polymer, or cellulose acetate butylate.