Liquid crystal display device

Patent metadata

Field	Value
Publication number	US-2016289560-A1
Application number	US-201415035354-A
Country	US
Kind code	A1
Filing date	Nov 4, 2014
Priority date	Nov 12, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

Provided is a liquid crystal display device including first and second opposing substrates, a liquid crystal layer containing a liquid crystal composition between the first and second substrates, a plurality of gate lines and data lines arranged in a matrix on the first substrate, thin-film transistors disposed at intersections of the gate lines and the data lines, and pixel electrodes that are driven by the transistors and that are made of a transparent conductive material. Each thin-film transistor includes a gate electrode, an oxide semiconductor layer disposed over the gate electrode with an insulating layer therebetween, and source and drain electrodes electrically connected to the oxide semiconductor layer. The liquid crystal composition contains at least one compound selected from the group consisting of compounds represented by general formulas (LC1) and (LC2) and at least one compound selected from the group consisting of compounds represented by general formulas (II-a) to (II-f).

First claim

1 . A liquid crystal display device comprising:
first and second opposing substrates; a liquid crystal layer comprising a liquid crystal composition between the first and second substrates; a plurality of gate lines and data lines arranged in a matrix on the first substrate; thin-film transistors disposed at intersections of the gate lines and the data lines; and pixel electrodes that are driven by the transistors and that comprise a transparent conductive material, each thin-film transistor comprising a gate electrode, an oxide semiconductor layer disposed over the gate electrode with an insulating layer therebetween, and source and drain electrodes electrically connected to the oxide semiconductor layer, wherein the liquid crystal composition comprises: at least one compound selected from the group consisting of compounds represented by general formulas (LC1) and (LC2):

wherein R LC11 and R LC21 are each independently an alkyl group of 1 to 15 carbon atoms, wherein one or more —CH 2 — groups in the alkyl group are optionally replaced with —O—, —CH═CH—, —CO—, —OCO—, —COO—, or —C≡C— such that no oxygen atoms are directly adjacent to each other, and one or more hydrogen atoms in the alkyl group are optionally replaced with halogen; A LC11 and A LC21 are each independently any of the following structures:

(wherein one or more —CH 2 — groups in the cyclohexylene group are optionally replaced with oxygen; one or more —CH═ groups in the 1,4-phenylene group are optionally replaced with nitrogen; and one or more hydrogen atoms in the structures are optionally replaced with fluorine, chlorine, —CF 3 , or —OCF 3 ); X LC11 , X LC12 , and X LC21 to X LC23 are each independently hydrogen, chlorine, fluorine, —CF 3 , or —OCF 3 ; Y LC11 and Y LC21 are each independently hydrogen, chlorine, fluorine, cyano, —CF 3 , —OCH 2 F, —OCHF 2 , or —OCF 3 ; Z LC21 and Z LC21 are each independently a single bond, —CH═CH—, —CF═CF 2 —, —C≡C—, —CH 2 CH 2 —, —(CH 2 ) 4 —, —OCH 2 —, —CH 2 O—, —OCF 2 —, —CF 2 O—, —COO—, or —OCO—; and m LC11 and m LC21 are each independently an integer of 1 to 4, wherein each occurrence of A LC11 , A LC21 , Z LC11 , and Z LC21 , if present, may be the same or different; and
at least one compound selected from the group consisting of compounds represented by general formulas (II-a) to (II-f):

wherein R 19 to R 30 are each independently an alkyl group of 1 to 10 carbon atoms, an alkoxy group of 1 to 10 carbon atoms, or an alkenyl group of 2 to 10 carbon atoms; and X 21 is hydrogen or fluorine.

2 . The liquid crystal display device according to claim 1 , wherein the oxide semiconductor layer comprises an oxide containing at least one element selected from In, Ga, Zn, and Sn.

3 . The liquid crystal display device according to claim 1 , wherein the oxide semiconductor layer comprises an oxide containing In, Ga, and Zn.

4 . The liquid crystal display device according to claim 1 , wherein the liquid crystal composition comprises, as the compounds represented by general formula (LC1) and (LC2), at least one compound selected from the group consisting of compounds represented by general formula (LC-I):

wherein
R 31 is an alkyl group of 1 to 10 carbon atoms, an alkoxy group of 1 to 10 carbon atoms, an alkenyl group of 2 to 10 carbon atoms, or an alkenyloxy group of 2 to 10 carbon atoms;
M 31 to M 33 are each independently trans-1,4-cyclohexylene, 1,4-phenylene, or naphthalene-2,6-dienyl, wherein one or more non-adjacent —CH 2 — groups in the trans-1,4-cyclohexylene group are optionally replaced with —O— such that no oxygen atoms are directly adjacent to each other, one or more non-adjacent —CH═ groups in the phenylene group are optionally replaced with —N═, any hydrogen atom present in the group is optionally replaced with fluorine, and any hydrogen atom present in the naphthalene-2,6-dienyl group is optionally replaced with fluorine;
M 34 is represented by any of the following formulas:

wherein X 31 , X 32 , X 41 , X 42 , and X 43 are each independently hydrogen or fluorine, and Y 31 and Y 32 are each fluorine, chlorine, cyano, —CF 3 , —OCH 2 F, —OCHF 2 , or —OCF 3 ); and
n 31 and n 32 are each independently 0, 1, or 2, with the proviso that n 31 +n 32 is 0, 1, or 2, wherein each occurrence of M 31 and M 33 , if present, may be the same or different, and n 33 is 0 or 1.

5 . The liquid crystal display device according to claim 1 , wherein the liquid crystal layer further comprises a compound represented by general formula (LC):

wherein
R LC is an alkyl group of 1 to 15 carbon atoms, wherein one or more —CH 2 — groups in the alkyl group are optionally replaced with —O—, —CH═CH—, —CO—, —OCO—, —COO—, or —C≡C— such that no oxygen atoms are directly adjacent to each other, and one or more hydrogen atoms in the alkyl group are optionally replaced with halogen;
A LC1 and A LC2 are each independently a group selected from the group consisting of
(a) trans-1,4-cyclohexylene (wherein one or more non-adjacent —CH 2 — groups present in the group are optionally replaced with oxygen or sulfur),
(b) 1,4-phenylene (wherein one or more non-adjacent —CH═ groups present in the group are optionally replaced with nitrogen), and
(c) 1,4-bicyclo(2.2.2)octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, and chromane-2,6-diyl,

wherein one or more hydrogen atoms present in groups (a), (b), and (c) are each optionally replaced with fluorine, chlorine, —CF 3 , or —OCF 3 ;
Z LC is a single bond, —CH═CH—, —CF═CF—, —C≡C—, —CH 2 CH 2 —, —(CH 2 ) 4 —, —OCH 2 —, —CH 2 O—, —OCF 2 —, —CF 2 O—, —COO—, or —OCO—;
Y LC is hydrogen, fluorine, chlorine, cyano, or an alkyl group of 1 to 15 carbon atoms, wherein one or more —CH 2 — groups in the alkyl group are optionally replaced with —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF 2 O—, or —OCF 2 — such that no oxygen atoms are directly adjacent to each other, and one or more hydrogen atoms in the alkyl group are optionally replaced with halogen; and
a is an integer of 1 to 4, wherein if a is 2, 3, or 4, each occurrence of A LC1 may be the same or different, and each occurrence of Z LC may be the same or different,
with the proviso that compounds represented by general formulas (LC1), (LC2), and (II-a) to (II-f) are excluded.

6 . The liquid crystal display device according to claim 1 , wherein the liquid crystal layer further comprises a polymer of a liquid crystal composition comprising at least one polymerizable compound selected from the group consisting of:
polymerizable compounds represented by general formula (VI):

wherein X 3 is hydrogen or methyl; Sp 3 is a single bond, an alkylene group of 1 to 8 carbon atoms, or —O—(CH 2 ) t — (wherein t is an integer of 2 to 7, and the oxygen atom is linked to the aromatic ring); V is a linear or branched polyvalent alkylene group of 2 to 20 carbon atoms or a polyvalent cyclic substituent of 5 to 30 carbon atoms, wherein the a

Assignees

• Dainippon Ink & Chemicals

Inventors

• Ogawa Shinji
• Iwashita Yoshinori

Classifications

• C09K19/0403 Primary

  the structure containing one or more specific, optionally substituted ring or ring systems · CPC title

• C09K19/3003

  Compounds containing at least two rings in which the different rings are directly linked (covalent bond) · CPC title

• G02F1/133365

  Cells in which the active layer comprises a liquid crystalline polymer · CPC title

• G02F1/1368

  in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} · CPC title

• C09K2019/0466

  the linking chain being a -CF2O- chain · CPC title