Liquid crystal display panel and composition of liquid crystal layer thereof

• US 8,075,959 B2
• Filed: 05/05/2009
• Issued: 12/13/2011
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Hsieh, Chung-Ching, Lin, Yang-Chu, Pai, Chia-Hsuan, Chen, Te-Sheng, Sugiura, Norio
• Primary Examiner(s): Visconti, Geraldina
• Application Number:
  US12/435,617
• Publication Number:
  US 20090324855A1
• Time in Patent Office: 952 Days
• Field of Search: 252/299.01, 252/299.6, 428/1.1, 428/1.3, 349/167, 349/182, 430/20
• US Class Current: 428/1.1
• CPC Class Codes: C09K 19/06 Non-steroidal liquid crystal compounds
• CPC Class Codes: C09K 19/12 at least two benzene rings directly linked, e.g. biphenyls
• CPC Class Codes: C09K 19/32 containing condensed ring systems, i.e. fused, bridged or spiro ring systems
• CPC Class Codes: C09K 19/322 Compounds containing a naphthalene ring or a completely or partially hydrogenated naphthalene ring
• CPC Class Codes: C09K 19/3402 having oxygen as hetero atom sugars C09K19/0422
• CPC Class Codes: C09K 2019/0448 the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate
• CPC Class Codes: C09K 2019/3425 Six-membered ring with oxygen(s) in fused, bridged or spiro ring systems
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• 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: G02F 1/133715 by first depositing a monomer
• CPC Class Codes: G02F 1/137 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
• CPC Class Codes: G02F 1/13775 Polymer-stabilized liquid crystal layers

Abstract

A liquid crystal display (LCD) panel includes a liquid crystal (LC) layer interposed between top and bottom substrates. The LC layer includes a plurality of LC compounds and a stabilization-aligned polymer polymerized from a plurality of polymerizable monomers and formed on at least one surface of the top substrate or the bottom substrate. The plurality of LC compounds comprise first, second, and third LC compounds in which the third LC compound is selected from the group consisting of a compound 3A, a compound 3B, a compound 3C, and combinations thereof. As seen from the chemical formulae, the plurality of LC compounds have condensed rings so that sensitivity to light and heat is reduced and reliability of the LCD panel is improved.

Claims

1. A liquid crystal display (LCD) panel, comprising:

a bottom substrate and a top substrate; and

a liquid crystal (LC) layer interposed between the top substrate and the bottom substrate,

wherein the LC layer is comprised of a plurality of LC compounds and a stabilization-aligned polymer,

wherein the stabilization-aligned polymer is polymerized from a plurality of polymerizable monomers and formed on at least one surface of the top substrate or the bottom substrate,

wherein the LC compounds comprise a first LC compound, a second LC compound, and a third LC compound,

wherein the first LC compound is represented by chemical formula (1) as follows;

2. The LCD panel according to claim 1, wherein, when “

R¹”

, “

R²”

, “

R³”

, “

R⁴” and

“

R⁵”

independently denote an alkyl group having 1˜

12 carbon atoms or an alkenyl group having 2˜

12 carbon atoms, one or two non-adjacent —

CH₂—

groups of “

R¹”

, “

R²”

, “

R³”

, “

R⁴” and

“

R⁵”

are replaced by an oxygen atom or a sulfur atom.

3. The LCD panel according to claim 1, wherein, when “

R¹”

, “

R²”

, “

R³”

, “

R⁴” and

“

R⁵”

independently denote an alkyl group having 1˜

12 carbon atoms or an alkenyl group having 2˜

12 carbon atoms, at least one hydrogen atom is replaced by a fluorine atom or a chlorine atom.

4. The LCD panel according to claim 1, wherein, when “

A¹”

, “

A²”

, “

A³”

, “

A⁴”

, “

B¹”

, “

B²”

, “

B³”

, “

B⁴” and

“

B⁵”

independently denote trans 1,4-cyclohexylene, one or two non-adjacent —

CH₂—

groups thereof are replaced by oxygen atom or sulfur atom.

5. The LCD panel according to claim 1, wherein, when “

A¹”

, “

A²”

, “

A³”

, “

A⁴”

, “

B¹”

, “

B²”

, “

B³”

, “

B⁴” and

“

B⁵”

independently denote 1,4-phenylene, at least one —

CH—

group thereof is replaced by a nitrogen atom.

6. The LCD panel according to claim 1, wherein, when “

A¹”

, “

A²”

, “

A³”

, “

A⁴”

, “

B¹”

, “

B²”

, “

B³”

, “

B⁴” and

“

B⁵”

independently denote 1,2,3,4-tetrahydronaphthalene-2,6-diyl, the hydrogen atoms thereof are replaced by —

CN or halogen.

7. The LCD panel according to claim 1, wherein the LC compounds comprise the first LC compound, “

W¹” and

“

W²”

are fluorine atoms, b, c, d=0, a=1, “

Z¹”

is a methyoxy group, and “

A¹”

is a trans 1,4-cyclohexylene group.

8. The LCD panel according to claim 1, wherein the LC compounds comprise the second LC compound, “

R⁴”

is a vinyl group, p=1, “

B¹” and

“

B²”

are trans 1,4-cyclohexylene groups, and “

Y¹” and

“

Y²”

are respectively a single bond.

9. The LCD panel according to claim 1, wherein the LC compounds comprise the second LC compound, p=1, “

Y²”

is a vinyl group, “

B¹” and

“

B²”

are trans 1,4-cyclohexylene groups, and “

Y¹”

is a single bond.

10. The LCD panel according to claim 1, wherein the LC compounds comprise the compound 3A, “

L¹”

, “

L²”

, “

L⁴” and

“

L⁵”

are hydrogen atoms, “

Y⁴”

is a single bond, q=0, and “

B³”

is a trans 1,4-cyclohexylene group.

11. The LCD panel according to claim 1, wherein the LC compounds comprise the compound 3A, “

L¹”

, “

L²”

, “

L⁴” and

“

L⁵”

are hydrogen atoms, “

Y⁴”

is a single bond, q=1, “

B⁴”

is a trans 1,4-cyclohexylene group or a 1,4-phenylene group, “

Y³”

is a single bond, “

B³”

is a trans 1,4-cyclohexylene group, and “

R⁵”

is a vinyl group.

12. The LCD panel according to claim 1, wherein the LC compounds comprise the compound 3B, “

L⁶”

, “

L⁷” and

“

L⁸”

are fluorine atoms, “

L¹⁰”

, “

L¹¹” and

“

L¹²”

are hydrogen atoms, r=0, “

Y⁴”

is a methyoxy group, q=0, and “

B³”

is a trans 1,4-cyclohexyl group.

13. The LCD panel according to claim 1, wherein the LC compounds comprise the compound 3B, wherein “

L⁶”

, “

L⁷” and

“

L⁸”

are fluorine atoms, “

L¹⁰”

, “

L¹¹” and

“

L¹²”

are hydrogen atoms, r=0, “

Y⁴”

is a methyoxy group, q=1, “

B⁴”

is a trans 1,4-cyclohexylene group, “

Y³”

is a single bond, and “

B³”

is a trans 1,4-cyclohexylene group.

14. The LCD panel according to claim 1, wherein the plurality of polymerizable monomers have a polymerizable group selected from one of groups VI, VII, VIII, IX and X,

wherein group VI is represented by chemical formula (VI) as follows:

15. The LCD panel according to claim 1, wherein, when “

L_m”

is an alkylcarbonyloxy group having 1˜

7 carbon atoms, one or more than one hydrogen atom of “

L_m”

is replaced by a fluorine atom or a chlorine atom.

16. The LCD panel according to claim 1, wherein the “

R”

is a straight-chain or branched-chain alkyl group having 1˜

12 carbon atoms, and wherein one or two non-adjacent —

CH₂—

groups of “

R”

are replaced by an oxygen atom, a sulfur atom, a vinyl group, a carbonyl group, a carboxyl group, a carbothio group, or an alkyne group.

17. The LCD panel according to claim 1, wherein the polymer has a surface roughness that approximately ranges between 10˜

20 nm.

18. The LCD panel according to claim 1, further comprising an initiator agent that absorbs light energy or heat energy to activate the plurality of polymerizable monomers to polymerize the same, wherein the initiator agent is present in an amount of less than 0.002% of total weight of the LC layer.

19. The LCD panel according to claim 1, wherein the plurality of polymerizable monomers are present in an amount of approximately 0.1˜

10% of total weight of the LC layer.