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1. (WO2018199141) POLYVINYL ALCOHOL FILM, POLARIZING FILM AND POLARIZING PLATE, AND POLYVINYL ALCOHOL FILM PRODUCTION METHOD

Pub. No.:    WO/2018/199141    International Application No.:    PCT/JP2018/016754
Publication Date: Fri Nov 02 00:59:59 CET 2018 International Filing Date: Thu Apr 26 01:59:59 CEST 2018
IPC: G02B 5/30
B29C 55/06
B29C 55/08
G02F 1/1335
B29K 29/00
B29L 7/00
B29L 11/00
Applicants: THE NIPPON SYNTHETIC CHEMICAL INDUSTRY CO., LTD.
日本合成化学工業株式会社
Inventors: SHIMIZU Toshihiro
清水 俊宏
KITAMURA Shuichi
北村 秀一
TERAMOTO Yuuichi
寺本 裕一
Title: POLYVINYL ALCOHOL FILM, POLARIZING FILM AND POLARIZING PLATE, AND POLYVINYL ALCOHOL FILM PRODUCTION METHOD
Abstract:
A polyvinyl alcohol film which has an excellent balance of swelling properties and stretching properties during polarizing film manufacture, does not result in rupture during thin polarizing film production, and enables a polarizing film to be obtained that exhibits high polarization performance and has few color irregularities, a polarizing film and polarizing plate using said polyvinyl alcohol film, and a polyvinyl alcohol film production method are provided. This polyvinyl alcohol film is elongate and no more than 40 μm thick, and is characterized in that, when immersed in 30°C water for 5 minutes, the swelling (SA), the width-direction swelling (SX), the length-direction swelling (SY), and the swelling (SB) during uniaxial stretch in which the stretch ratio triples at a stretch speed of 0.12 m/min in 30°C water satisfy formulas (1) to (3) below. (1)... 190% ≤ SA ≤ 230% (2)... 220% ≤ SB ≤ 310% (3)... 1.01 ≤ SY / SX ≤ 1.20