Liquid crystal display element

Patent metadata

Field	Value
Publication number	US-2016060523-A1
Application number	US-201414779508-A
Country	US
Kind code	A1
Filing date	Mar 18, 2014
Priority date	Mar 25, 2013
Publication date	Mar 3, 2016
Grant date	—

Abstract

The present invention relates to a PSA-mode liquid crystal display device including a polymer produced by polymerizing a polymerizable compound by energy ray irradiation in a state in which a mixture of the polymerizable compound and a liquid crystal composition is held between the first substrate and the second substrate, the polymer having a number-average molecular weight of 50,000 or more in terms of polystyrene. In a PSA-mode display device in which alignment of liquid crystal molecules substantially vertically aligned between the substrates is controlled by applying a voltage, a pre-tilt angle can be properly given without being inhibited. Therefore, the present invention provides a PSA-mode display device with good alignment stability, uniform alignment within the substrates, and no or suppressed display defects and a method for producing the same.

First claim

1 . A liquid crystal display device comprising a first substrate having a common electrode, a second substrate having a pixel electrode, a liquid crystal composition layer held between the first substrate and the second substrate, a polymer that regulates an alignment direction of a liquid crystal composition, and a vertical alignment film provided on at least one of the first substrate and the second substrate, the alignment direction of liquid crystal molecules in the liquid crystal composition layer being controlled by the vertical alignment film to be substantially vertical to the first substrate and the second substrate on the sides adjacent to the liquid crystal composition layer, wherein the liquid crystal molecules in the liquid crystal composition layer are controlled by applying, between the common electrode and the pixel electrode, a voltage substantially vertically to the first substrate and the second substrate, and the polymer has a number-average molecular weight of 50,000 or more in terms of polystyrene.

2 . The liquid crystal display device according to claim 1 , wherein the polymer is formed by polymerizing a polymerizable compound by energy ray irradiation in a state in which a mixture of the polymerizable compound and the liquid crystal composition is held between the first substrate and the second substrate.

3 . The liquid crystal display device according to claim 1 , wherein when the polymer is formed by polymerizing the polymerizable compound by energy ray irradiation, an electric field or voltage is applied between the first substrate and the second substrate.

4 . The liquid crystal display device according to claim 1 , wherein the energy ray is ultraviolet light.

5 . The liquid crystal display device according to claim 1 , wherein the mixture of the polymerizable compound and the liquid crystal composition is irradiated with ultraviolet light at a center wavelength of 365 nm with an intensity of irradiation of 5 mW/cm 2 to 50 mW/cm 2 .

6 . The liquid crystal display device according to claim 1 , wherein the polymerizable compound is a compound having two or more polymerizable groups.

7 . The liquid crystal display device according to claim 6 , wherein the polymerizable compound is a compound represented by general formula (II).

(in the formula, R 21 and R 22 each independently represent any one of formula (R-1) to formula (R-15) below,

S 21 and S 22 each independently represent an alkyl group having 1 to 12 carbon atoms or a single bond, a methylene group in the alkyl group may be substituted by an oxygen atom, —COO—, —OCO—, or —OCOO— so that oxygen atoms are not directly bonded to each other, L 21 represents a single bond, —O—, —CH 2 —, —OCH 2 —, —CH 2 O—, —CO—, —C 2 H 4 —, —COO—, —OCO—, —CH═CH—COO—, —COO—CH═CH—, —OCO—CH═CH—, —CH═CH—OCO—, —COOC 2 H 4 —, —OCOC 2 H 4 —, —C 2 H 4 OCO—, —C 2 H 4 COO—, —OCOCH 2 —, —CH 2 COO—, —CH═CH—, —CF═CH—, —CH═CF—, —CF═CF—, —CF 2 —, —CF 2 O—, —OCF 2 —, —CF 2 CH 2 —, CH 2 CF 2 —, —CF 2 CF 2 —, or —C≡C—, when a plurality of L 21 are present, they may be the same or different, M 21 represents a 1,4-phenylene group, a naphthalene-2,6-diyl group, an anthracene-2,6-diyl group, or a phenathrene-2,7-diyl group, which may be unsubstituted or in which a hydrogen containing the group may be substituted by a fluorine atom, a chlorine atom, an alkyl group having 1 to 8 carbon atoms, a halogenated alkyl group, a halogenated alkoxy group, an alkoxy group, a nitro group, or
—S 21 —R 21

M 22 represents a 1,4-phenylene group, a 1,4-cyclohexylene group, a naphthalene-2,6-diyl group, an anthracene-2,6-diyl group, or a phenathrene-2,7-diyl group, which may be unsubstituted or in which a hydrogen containing the group may be substituted by a fluorine atom, a chlorine atom, an alkyl group having 1 to 8 carbon atoms, a halogenated alkyl group, a halogenated alkoxy group, an alkoxy group, a nitro group, or
—S 21 —R 21

when a plurality of M 22 are present, they may be the same or different, and m 21 is 0, 1, 2, or 3).

Assignees

• Dainippon Ink & Chemicals

Inventors

• Hara Tomoaki
• Wu Wei
• Kawakami Shotaro

Classifications

• G02F2001/133742

  Physics · mapped topic

• G02F1/133711

  by organic films, e.g. polymeric films · CPC title

• C09K19/542

  Macromolecular compounds · CPC title

• C09K19/3066 Primary

  in which the rings are linked by a chain containing carbon and oxygen atoms, e.g. esters or ethers · CPC title

• G02F1/133788

  by light irradiation, e.g. linearly polarised light photo-polymerisation · CPC title