PHASE DIFFERENCE FILM

• US 20200131309A1
• Filed: 12/18/2019
• Published: 04/30/2020
• Est. Priority Date: 06/28/2017
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: UEHIRA, Shigeki, MOROOKA, Naoyuki, NAKAYAMA, Takafumi
• Granted Patent: US 10,899,882 B2
• Time in Patent Office: Days
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: C08G 64/04 Aromatic polycarbonates
• CPC Class Codes: C08G 64/045 containing aliphatic unsaturation
• CPC Class Codes: C08G 64/16 Aliphatic-aromatic or araliphatic polycarbonates
• CPC Class Codes: C08G 64/1608 saturated
• CPC Class Codes: C08G 64/226 and alcohols
• CPC Class Codes: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: C09K 2323/035 Ester polymer, e.g. polycarbonate, polyacrylate or polyester
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133637 characterised by the wavelength dispersion

Abstract

An object of the present invention is to provide a phase difference film that can exhibit sufficient reciprocal wavelength dispersibility. The present invention includes a copolymer containing at least one selected from a unit represented by Formula (1) and a unit represented by Formula (2), and a unit represented by Formula (3), in which 20 nm<Re (548)<300 nm, 0.5<Re (446)/Re (548)<1.0, and 1.0<Re (629)/Re (548)<2.0. Here, Re (446), Re (548), and Re (629) represent in-plane retardations at wavelengths of 446 nm, 548 nm, and 629 nm, respectively.

Claims

1. A phase difference film comprising:

a copolymer containing at least one selected from a unit represented by Formula (1) and a unit represented by Formula (2), and a unit represented by Formula (3),

wherein 20 nm<

Re (548)<

300 nm,

0.5<

Re (446)/Re (548)<

1.0, and

1.0<

Re (629)/Re (548)<

2.0;

here, Re (446), Re (548), and Re (629) represent in-plane retardation at respective wavelengths of 446 nm, 548 nm, and 629 nm;

2. The phase difference film according to claim 1, wherein the unit represented by Formula (1) is a unit represented by Formula (11);

3. The phase difference film according to claim 1, wherein the unit represented by Formula (2) is a unit represented by Formula (21);

4. The phase difference film according to claim 3, wherein in Formula (21), Y²¹ and Y²² are nitrogen atoms.

5. The phase difference film according to claim 1, wherein, in Formula (3), X³² represents an alkylene group having 5 to 20 carbon atoms having at least one selected from an alicyclic ring, a heterocyclic ring, and an aromatic ring as a substituent, a cycloalkylene group having 4 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a group obtained by combining these, here ring-constituting atoms of the cycloalkylene group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom.

6. The phase difference film according to claim 1, wherein the unit represented by Formula (3) is a unit selected by the following constitutional units;

7. The phase difference film according to claim 1, a photoelastic coefficient is 0 cm²/N to 40×

10<sup>−

8</sup> cm²/N.