Polarizing film, method for molding polarizing film, and method for producing polarizing lens

Patent metadata

Field	Value
Publication number	US-12337559-B2
Application number	US-201917059825-A
Country	US
Kind code	B2
Filing date	May 30, 2019
Priority date	May 31, 2018
Publication date	Jun 24, 2025
Grant date	Jun 24, 2025

Abstract

A polarizing film having a molded shape, in which a difference in average transmittance of the polarizing film at a wavelength of 400 to 700 nm is 5% or less before and after molding the shape of the polarizing film. In addition, when molding the polarizing film into a shape such as a curved surface, the polarizing film is heat-treated in a temperature range of Tg−20° C. or higher and Tg+10° C. or lower, where Tg is a glass transition point of a resin constituting the polarizing film. Further, one chamber is divided into a first space and a second space by the polarizing film disposed in the chamber, and the polarizing film is transfer-molded along a molding surface by a differential pressure generated by making a pressure in the first space and a pressure in the second space different from each other.

First claim

The invention claimed is:

1. A method for molding a polarizing film, the method comprising:
molding the polarizing film into a curved shape, wherein
when the polarizing film is molded, the polarizing film is heat-treated in a temperature range of Tg−20° C. or higher and Tg+10° C. or lower, where Tg is a glass transition point of a resin constituting the polarizing film,
one chamber is divided into a first space and a second space,
a molding die is disposed in the second space,
the polarizing film is disposed in the chamber,
the polarizing film is transfer-molded along a convex molding surface of the molding die by a differential pressure generated by making a pressure in the first space and a pressure in the second space different from each other, and
the convex molding surface of the molding die is configured to be in contact with only a portion of the polarizing film that is configured to be formed into a polarizing lens, wherein
a surface of the polarizing film facing the first space remains in a non-contact state during the transfer-molding.

2. The method for molding a polarizing film according to claim 1 , wherein when the shape of the polarizing film is molded, the polarizing film is left in an atmosphere having a relative humidity of 20% or more and 70% or less.

3. The method for molding a polarizing film according to claim 2 , wherein the polarizing film before molding is left in the atmosphere having a relative humidity of 20% or more and 70% or less, and then heat-treated.

4. The method for molding a polarizing film according to claim 1 , wherein a difference of average transmittance of the polarizing film at a wavelength of 400 to 700 nm is 5% or less before and after molding the shape of the polarizing film.

5. The method for molding a polarizing film according to claim 1 , wherein the polarizing film is used for producing the polarizing lens having the polarizing film embedded inside the polarizing lens.

6. A method for producing a polarizing lens, the method comprising:
a step of molding the polarizing film by the method for molding the polarizing film according to claim 1 ; and
a step of molding a polarizing lens by sandwiching the molded polarizing film inside the polarizing lens.

Assignees

• Hoya Lens Thailand Ltd

Inventors

• MATSUE Aoi
• Hamamoto Terufumi
• Yamashita Teruo

Classifications

• G02C7/12

  Polarisers · CPC title

• G02B5/30

  Polarising elements (light-modulating devices with active elements G02F1/00) · CPC title

• B29D11/00788

  Producing optical films · CPC title

• G02B5/305

  including organic materials, e.g. polymeric layers · CPC title

• B29C41/045

  the axis being placed vertically, e.g. spin casting · CPC title