Polarizing sheet and polarizing lens provided with same
Provided is a polarizing sheet that can precisely impart a desired curved shape without causing whitening when bending is carried out. A polarizing sheet of an embodiment of the present invention having a structure in which a polyamide resin film ( 1 ), a polarizing film, and a polyamide resin film ( 2 ) are laminated in this order, wherein a retardation value of the polyamide resin film ( 1 ) is from 10 to 3000 nm, and the retardation value of the polyamide resin film ( 1 ) and a retardation value of the polyamide resin film ( 2 ) satisfy Formula (r): [Retardation Value of Polyamide Resin Film (1)]−[Retardation Value of Polyamide Resin Film (2)]≥10 nm (r).
1. A method for producing a polarizing sheet having a curved shape, the method comprising:
placing a polarizing sheet including a polyamide resin film ( 1 ), a polarizing film, and a polyamide resin film ( 2 ) disposed in this order in such a manner that the polyamide resin film ( 1 ) side of the polarizing sheet is in contact with a mold heated at a temperature from 80 to 120° C. for curved surface molding;
bringing the sheet into close contact with the mold; and
transferring a shape of the mold by a vacuum molding method to the sheet to bring the sheet to have a curved shape,
wherein a retardation value of the polyamide resin film ( 1 ) is from 2000 to 2500 nm, and the retardation value of the polyamide resin film ( 1 ) and a retardation value of the polyamide resin film ( 2 ) satisfy Formula (r):
2000 nm<[Retardation Value of Polyamide Resin Film ( 1 )]−[Retardation Value of Polyamide Resin Film ( 2 )]<2500 nm (r).
2. The method for producing a polarizing sheet having a curved shape according to claim 1 , wherein the polyamide resin film ( 2 ) has a thickness from 10 to 2000 μm.
3. The method for producing a polarizing sheet having a curved shape according to claim 1 , wherein the polyamide resin film ( 1 ) comprises an alicyclic polyamide resin.
4. The method for producing a polarizing sheet having a curved shape according to claim 3 , wherein the alicyclic polyamide resin has a repeating unit represented by Formula (ad) below:
where X represents a single bond or a divalent hydrocarbon group, L represents a divalent hydrocarbon group, R 1 and R 2 each represent an alkyl group, and m and n each represent an integer from 0 to 4.
5. A method for producing a polarizing lens, the method comprising:
producing a polarizing sheet having a curved shape by the method according to claim 1 ; and
thermally fusing a polyamide resin composition to the polyamide resin film ( 2 ) side of the polarizing sheet.
6. A method for producing spectacles including a polarizing lens,
the method comprising:
producing a polarizing sheet having a curved shape by the method according to claim 1 ; and
thermally fusing a polyamide resin composition to the polyamide resin film ( 2 ) side of the polarizing sheet.