Polarizer, polarizing plate, and image display apparatus
There is provided a polarizer that can realize multi-functionalization and high-functionalization of an electronic device, such as an image display apparatus. A polarizer according to an embodiment of the present invention includes a resin film containing iodine, wherein the polarizer has formed therein a transparent portion having a transmittance higher than that of another portion, and when the polarizer is placed under an environment having a temperature of 60° C. and a humidity of 90% for 2 hours, a transmittance change (ΔTs) of the transparent portion is 10% or less.
1. A polarizer, comprising a resin film containing iodine, wherein the polarizer has formed therein a transparent portion having a transmittance higher than that of another portion, and when the polarizer is placed under an environment having a temperature of 60° C. and a humidity of 90% for 2 hours, a transmittance change (ΔTs) of the transparent portion is 10% or less.
2. The polarizer according to claim 1 , wherein the transparent portion has an iodine content of 1.0 wt % or less.
3. The polarizer according to claim 1 , wherein the transparent portion has a content of at least one of an alkali metal or an alkaline earth metal of 0.5 wt % or less.
4. The polarizer according to claim 1 , wherein the resin film contains a polyvinyl alcohol-based resin, and the polyvinyl alcohol-based resin has a saponification degree of 99.0 mol % or more.
5. The polarizer according to claim 1 , wherein the transparent portion corresponds to a camera portion of an image display apparatus on which the polarizer is mounted.
6. The polarizer according to claim 1 , wherein the resin film has a thickness of 8 μm or less.
7. The polarizer according to claim 6 , wherein optical characteristics in the another portion satisfy relationships of P>−(10 0.929T-42.4 −1)×100, provided that T<42.3, and P≥99.9, provided that T≥42.3, where P represents a polarization degree (%) and T represents a single axis transmittance (%).
8. A polarizing plate, comprising the polarizer having formed therein the transparent portion of claim 1 .
9. The polarizing plate according to claim 8 , wherein the polarizing plate has a shape corresponding to an image display apparatus on which the polarizing plate is mounted, and the transparent portion is formed to be spaced apart from an end side.
10. An image display apparatus, comprising the polarizing plate of claim 8 .
11. A method of producing the polarizer of claim 1 , the method comprising decolorizing a desired portion of a resin film containing a dichromatic substance.
12. The production method according to claim 11 , wherein the decolorizing is performed by bringing a basic solution into contact with the resin film containing the dichromatic substance.
13. The production method according to claim 12 , further comprising bringing an acidic solution into contact with a portion of the resin film with which the basic solution has been brought into contact.
14. The production method according to claim 12 , wherein at a time of the contact of the basic solution, a surface of the resin film is covered with a surface protective film so that at least part of the surface of the resin film may be exposed.