Title:
METHOD FOR PRODUCING POLARIZING FILM AND POLARIZING FILM
Document Type and Number:
WIPO Patent Application WO/2022/113958
Kind Code:
A1
Abstract:
This method for producing a polarizing film comprises a dyeing step for dyeing a PVA film with a dichroic pigment, a stretching step for uniaxially stretching in an aqueous solution comprising boric acid, and a drying step, wherein: the aqueous solution of the stretching step has a boric acid concentration of 1-3 mass%; the total stretch ratio is 5.5X-7.4X; the total neck-in rate (A) as represented by expression (1) is 57.5-61.0%; the neck-in rate (B) as represented by expression (2) in the stretching step is 31.0-38.0%, and the neck-in rate (C) as represented by expression (3) in the drying step is 9.8-16.5%. (A)={(X1-X2)/X1}×100(1) (B)={(Y1-Y2)/Y1}×100(2) (C)={(Z1-X2)/Z1}×100(3) (X1 represents the width (m) before the dyeing step, X2 represents the width (m) after the drying step, Y1 represents the width (m) before the stretching step, Y2 represents the width (m) after the stretching step, and Z1 represents the width (m) before the drying step.)
Inventors:
OHASHI WATARU (JP)
NAKAI SHINJI (JP)
NAKAI SHINJI (JP)
Application Number:
PCT/JP2021/042860
Publication Date:
June 02, 2022
Filing Date:
November 22, 2021
Export Citation:
Assignee:
KURARAY CO (JP)
International Classes:
G02B5/30; B29C55/06
Domestic Patent References:
| WO2017138551A1 | 2017-08-17 | |||
| WO2020080183A1 | 2020-04-23 | |||
| WO2019146677A1 | 2019-08-01 |
Foreign References:
| JP2017142347A | 2017-08-17 | |||
| JP2011164553A | 2011-08-25 | |||
| JP2013218106A | 2013-10-24 |
Attorney, Agent or Firm:
LIGHTHOUSE INTERNATIONAL PATENT FIRM (JP)
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