OPTICAL FILM AND FLEXIBLE DISPLAY DEVICE

WIPO Patent Application WO/2020/138045

A1

Provided is an optical film having excellent appearance quality, the appearance quality of the optical film not being degraded upon contact with alcohol. The optical film comprises a polyamide-imide resin that contains at least: a structural unit derived from a tetracarboxylic acid compound and represented by formula (a); a structural unit derived from a dicarboxylic acid compound and represented by formula (b); and a structural unit derived from a diamine compound and represented by formula (c) [in formula (a), Y represents a tetravalent organic group; in formula (b), Z represents a divalent organic group; in formula (c), X is a divalent organic group; Rc, independently of one another, represents a hydrogen atom or a bond; and * represents a bond]. The polyamide-imide resin includes at least one structural unit selected from the group consisting of a structural unit (a1) and a structural unit (b1). The structural unit (a1) is represented by formula (a) as the structural unit derived from a tetracarboxylic acid compound, where Y is represented by formula (1) [in formula (1), Ra, independently of one another, represents a hydrogen atom, a C1-C12 alkyl group, a C1-C12 alkoxy group or a C6-C12 aryl group; hydrogen atoms included in Ra, independently of one another, may be substituted with halogen atoms; n represents an integer of 0 to 2; * represents a bond; R* represents a bond if Y is represented by formula (1), and represents Ra if Z is represented by formula (1)]. The structural unit (b1) is represented by formula (b) as the structural unit derived from a dicarboxylic acid compound, where Z is represented by formula (1). The absolute value of the difference ΔL* between lightness L1 * of the optical film, the lightness L1 * being obtained by measuring reflected light and based on the L*a*b* color system, and lightness L2 ＊ of the optical film that has been in contact with ethanol for 40 minutes, the lightness L2 ＊ being obtained by measuring the surface color difference and based on the L*a*b* color system, is no more than 0.5.

SUGIYAMA HIROKO (JP)
MIYAMOTO KOJI (JP)
IKEUCHI JUNICHI (JP)
MASUI KENTARO (JP)
KIM SEONGMIN (JP)
PYEON BORAM (JP)

PCT/JP2019/050541

July 02, 2020

December 24, 2019

Click for automatic bibliography generation  

SUMITOMO CHEMICAL CO (JP)

C08G73/14; G02B5/30

WO2017209413A1	2017-12-07
WO2017209414A1	2017-12-07
WO2017204462A1	2017-11-30
WO2018135433A1	2018-07-26

KR20180009651A

2018-01-29

NAKAYAMA, Tohru et al. (JP)

View/Download PDF      PDF Help

Previous Patent: POLYAMIDE-BASED RESIN, OPTICAL FILM, AND FLEXIBLE DISPLAY DEVICE

Next Patent: OPTICAL FILM