Title:
POLARIZING FILM AND METHOD FOR PRODUCING SAME
Document Type and Number:
WIPO Patent Application WO/2017/138551
Kind Code:
A1
Abstract:
A method for producing a polarizing film, wherein a polyvinyl alcohol film is subjected to at least a swelling step, a dyeing step, a first crosslinking stretching step and a second crosslinking stretching step in this order, and wherein: the average polymerization degree of polyvinyl alcohols contained in the polyvinyl alcohol film is 2,500-3,500; the polyvinyl alcohol film is uniaxially stretched in an aqueous solution at 40-55°C containing 1-5% by mass of boric acid in the first crosslinking stretching step so that the stretch ratio during the first crosslinking stretching step is 1.1-1.3 times and the total stretch ratio is 2.5-3.5 times; and the polyvinyl alcohol film is uniaxially stretched in an aqueous solution at 60-70°C containing 1-5% by mass of boric acid in the second crosslinking stretching step so that the stretch ratio during the second crosslinking stretching step is 1.8-3.0 times and the total stretch ratio is 6-8 times. Consequently, a polarizing film having excellent polarization performance and low contraction stress is able to be produced.
Inventors:
OZONO TATSUYA (JP)
ASADA MITSUNORI (JP)
TSUJI YOSHIHISA (JP)
ASADA MITSUNORI (JP)
TSUJI YOSHIHISA (JP)
Application Number:
PCT/JP2017/004511
Publication Date:
August 17, 2017
Filing Date:
February 08, 2017
Export Citation:
Assignee:
KURARAY CO (JP)
International Classes:
G02B5/30; B29C55/06; G02F1/1335; B29K29/00; B29L7/00; B29L11/00
Domestic Patent References:
| WO2014050697A1 | 2014-04-03 |
Foreign References:
| JP2013105036A | 2013-05-30 | |||
| JP2016022690A | 2016-02-08 | |||
| JP2006126722A | 2006-05-18 | |||
| JP2013140324A | 2013-07-18 |
Attorney, Agent or Firm:
SETOUCHI INTERNATIONAL PATENT FIRM (JP)
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