KR20110054842A - Liquid crystal photo-alignment agent, liquid crystal photo-alignment film manufactured using the same, and liquid crystal display device including thereof - Google Patents

Abstract

PURPOSE: A liquid crystal photo-alignment agent is provided to ensure excellent printability, vertical alignment, and liquid crystal alignment and to prepare a liquid crystal photo-alignment film having excellent film uniformity. CONSTITUTION: A liquid crystal photo-alignment agent comprises: a first polymer including a polyamic acid having a repeating unit represented by chemical formula 1 and polyimide having a repeating unit represented by chemical formula 2, or combination thereof; a second polymer including polyimide having a repeating unit represented by chemical formula 3; and a solvent consisting of monoethylene glycol dimethyl ether and dipropylene glycol dimethyl ether.

Description

Liquid crystal photoalignment agent, a liquid crystal photoalignment film manufactured using the same, and a liquid crystal display device comprising the liquid crystal photoalignment layer.

A liquid crystal photoalignment agent, a liquid crystal photoalignment film prepared using the same, and a liquid crystal display device including the liquid crystal photoalignment film.

A liquid crystal display device (LCD) uses a liquid crystal alignment layer, and a polymer material is mainly used as the liquid crystal alignment layer. The liquid crystal alignment layer acts as a director in the arrangement of the liquid crystal molecules, so that the liquid crystal is moved by an electric field to form an image when the image is formed. In general, in order to obtain uniform brightness and high contrast ratio in the liquid crystal display, it is essential to orient the liquid crystal uniformly.

As a conventional method of orienting a liquid crystal, a rubbing method is used in which a polymer film such as polyimide is applied to a substrate such as glass, and the surface of the polymer film is rubbed in a predetermined direction with fibers such as nylon or polyester. However, the rubbing method may generate fine dust or electrostatic discharge (ESD) when the fibers and the polymer film are rubbed, which may cause serious problems in manufacturing the liquid crystal panel.

In order to solve the problem of the rubbing method, recently, an optical alignment method of inducing anisotropy (anisotropy) to a polymer film by light irradiation instead of friction and arranging liquid crystals using the same has been studied.

As a material that can be used in the photo-alignment method, polymers containing optical functional groups such as azobenzene, cumarine, chalcone, chalcone and cinnamate have been developed. These polymers are anisotropically reacted by photoisomerization or photocrosslinking due to polarized light irradiation, thereby causing anisotropy on the surface of the polymer and inducing molecular alignment of the liquid crystal in one direction.

In order to apply such liquid crystal alignment film materials to the liquid crystal display device substantially, optical stability and passion stability should be excellent and there should be no afterimage. However, conventionally known photo-orientation materials exhibit many problems in this respect.

In addition, a liquid crystal display device is generally coated with a liquid crystal photo-alignment agent on a glass substrate on which a transparent indium tin oxide (ITO) conductive film is deposited, and cured with heat to form an alignment layer, and then bonding two substrates to face each other The liquid crystal dropping method which inject | pours, drips, or a liquid crystal is dripped at one board | substrate, and joins and opposes a board | substrate, and is completed by the liquid crystal dropping method. In particular, the liquid crystal dropping method is mainly adopted in the fifth generation or more large and large lines.

Generally, a liquid crystal photoalignment film is formed by applying the liquid crystal photoalignment agent which melt | dissolved polyamic acid, a polyimide polymer, and a polyimide photopolymer in the organic solvent to a board | substrate by flexographic printing, etc., and then performing drying, baking, and light irradiation. do. At this time, when the printability, for example, spreadability and adhesion of the liquid crystal photoalignment agent is poor, film thickness variation occurs in the formed coating film, and the nonuniformity of the coating film may adversely affect the display characteristics of the liquid crystal display device.

Provided is a liquid crystal photoalignment agent excellent in printability, vertical alignment property and liquid crystal alignment property, and stable to process condition changes.

It provides a liquid crystal photoalignment film prepared using the liquid crystal photoalignment agent.

It provides a liquid crystal display device comprising the liquid crystal photo-alignment film.

According to an aspect of the present invention, a polyamic acid including a repeating unit represented by the following Chemical Formula 1, a polyimide including the repeating unit represented by the following Chemical Formula 2, or a first polymer including a combination thereof; A second polymer including a polyimide containing a repeating unit represented by Formula 3 below; And a solvent including monoethylene glycol dimethyl ether (DMG) and dipropylene glycol dimethyl ether (DMFDG).

[Formula 1]

[Formula 2]

(3)

In Chemical Formulas 1 to 3,

X ₁ , X ₂ and X ₃ are the same or different from each other, and each independently represent a tetravalent organic group derived from an alicyclic acid dianhydride or an aromatic acid dianhydride,

Y ₁ and Y ₂ are the same or different from each other, and each independently a divalent organic group derived from diamine,

Y ₃ is a divalent organic group derived from photodiamine selected from the group consisting of azobenzene photodiamine, cumarine photodiamine, chalcone photodiamine and cinnamate photodiamine. to be.

In the liquid crystal photoalignment agent, the monoethylene glycol dimethyl ether and the dipropylene glycol dimethyl ether may be included in a weight ratio of 10:90 to 90:10. In addition, the liquid crystal photoalignment agent may include the monoethylene glycol dimethyl ether and dipropylene glycol dimethyl ether such that the sum thereof is 5 to 80 wt% based on the total amount of the solvent.

The solvent may further include 2-butyl cellosolve (2-BC), wherein the 2-butyl cellosolve (2-BC) may be included in an amount of 1 to 50 wt% based on the total amount of the solvent.

The liquid crystal photoalignment agent may include 0.01 to 15 wt% of the first polymer, 0.01 to 15 wt% of the second polymer, and 30 to 99.98 wt% of the solvent. In addition, the liquid crystal photoalignment agent may include the first polymer and the second polymer in a weight ratio of 0.01: 99.99 to 99.99: 0.01.

The liquid crystal photoalignment agent may further include an epoxy compound, wherein the epoxy compound may be included in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the sum of the first polymer and the second polymer.

The liquid crystal photoalignment agent may have a solid content of 0.01 to 15% by weight, and may have a viscosity of 3 to 30 cps.

According to another aspect of the invention there is provided a liquid crystal photo-alignment film prepared by applying the liquid crystal photo-alignment agent to a substrate.

According to another aspect of the invention provides a liquid crystal display device comprising the liquid crystal photo-alignment film.

Other specific details of embodiments of the present invention are included in the following detailed description.

The liquid crystal photoalignment agent which can improve printability, the vertical alignment property, and the liquid crystal photoalignment, and is stable to process conditions changes is provided.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

Unless stated otherwise in the present specification, "alkyl group" means a C1 to C30 alkyl group, specifically means a C1 to C15 alkyl group, and "cycloalkyl group" means a C3 to C30 cycloalkyl group, specifically C3 To C15 cycloalkyl group, "heterocycloalkyl group" means C2 to C30 heterocycloalkyl group, specifically C2 to C15 heterocycloalkyl group, "alkylene group" means C1 to C30 alkylene group , Specifically, a C1 to C15 alkylene group, "alkoxy group" refers to a C1 to C30 alkoxy group, specifically a C1 to C15 alkoxy group, "cycloalkylene group" refers to a C3 to C30 cycloalkylene group It means specifically, C3 to C15 cycloalkylene group, "heterocycloalkylene group" means a C2 to C30 heterocycloalkylene group, specifically Means a C2 to C15 heterocycloalkylene group, "aryl group" means a C6 to C30 aryl group, specifically means a C6 to C20 aryl group, "heteroaryl group" means a C2 to C30 heteroaryl group, Specifically, C2 to C18 heteroaryl group, "arylene" group means C6 to C30 arylene group, specifically C6 to C20 arylene group, "heteroarylene group" means C2 to C30 heteroarylene Group, specifically, a C2 to C20 heteroarylene group, and "alkylaryl group" means a C7 to C30 alkylaryl group, specifically a C7 to C20 alkylaryl group, and "halogen atom" or " Halogen group "means F, Cl, Br or I.

Unless stated otherwise in the specification, a substituted alkyl group, substituted alkylene group, substituted cycloalkyl group, substituted cycloalkylene group, substituted heterocycloalkyl group, substituted heterocycloalkylene group, substituted aryl group, substituted aryl A ethylene group, a substituted heteroaryl group, a substituted heteroarylene group, a substituted pyrimidinyl group, a substituted pyridinyl group, a substituted thiophenyl group, a substituted furanyl group, a substituted naphthyl group and a substituted phenyl group are each independently a halogen group , An alkyl group substituted with a C1 to C30 alkyl group, a C1 to C30 haloalkyl group, a C6 to C30 aryl group, a C2 to C30 heteroaryl group, or a C1 to C20 alkoxy group, an alkylene group, a cycloalkyl group, a cycloalkylene group, a heterocycloalkyl group, a hetero Cycloalkylene group, aryl group, arylene group, heteroaryl group, heteroarylene group, pyrimidinyl group, pyridinyl group, thiophenyl group, furanyl group, naphthyl group and phenyl group it means.

Also, unless stated otherwise in the present specification, a heterocycloalkyl group, a heterocycloalkylene group, a heteroaryl group, and a heteroarylene group each independently contain one or more heteroatoms of N, O, S, Si, or P in one ring. It contains three, and the rest means a cycloalkylene group, an aryl group, and an arylene group which are carbon.

Also, unless stated otherwise, "aliphatic" means C1 to C30 alkyl, C2 to C30 alkenyl, C2 to C30 alkynyl, C1 to C30 alkylene, C2 to C30 alkenylene, or C2 to C30 alkynylene Specifically, C1 to C15 alkyl, C2 to C15 alkenyl, C2 to C15 alkynyl, C1 to C15 alkylene, C2 to C15 alkenylene, or C2 to C15 alkynylene, and "alicyclic" C3 to C30 cycloalkyl, C3 to C30 cycloalkenyl, C3 to C30 cycloalkynyl, C3 to C30 cycloalkylene, C3 to C30 cycloalkenylene, or C3 to C30 cycloalkynylene, specifically C3 to C30 cycloalkynylene C15 cycloalkyl, C3 to C15 cycloalkenyl, C3 to C15 cycloalkynyl, C3 to C15 cycloalkylene, C3 to C15 cycloalkenylene, or C3 to C15 cycloalkynylene, meaning "aromatic" C6 to C30 aryl, C2 to C30 heteroaryl, C6 to C30 arylene or C2 to C30 heteroarylene, specifically C6 to C16 aryl, C2 to C16 heteroaryl, C6 to C16 arylene or C2 to C16 Heteroarylene means.

Unless otherwise defined herein, “combination” generally means mixing or copolymerizing, and in alicyclic and aromatic organic groups, two or more rings form a fused ring, or two or more rings are single Bond, O, S, C (= O), CH (OH), S (= O), S (= O) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1≤p≤2 ), (CF ₂ ) _q (where 1 ≦ _q ≦ 2), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , C (CH ₃ ) (CF ₃ ) or C (═O) NH It means that they are connected to each other by. Here, "copolymerization" means block copolymerization or random copolymerization, and "copolymer" means block copolymers or random copolymer.

In addition, in this specification, "*" means the part connected with the same or different atom or formula.

Liquid crystal photo-alignment agent according to an aspect of the present invention is a polyamic acid comprising a repeating unit represented by the following formula (1), a polyimide comprising a repeating unit represented by the formula (2), or a first polymer comprising a combination thereof; A second polymer comprising a polyimide including a repeating unit represented by Formula 3 below; And a solvent comprising monoethylene glycol dimethyl ether (DMG) and dipropylene glycol dimethyl ether (DMFDG).

[Formula 1]

[Formula 2]

(3)

In Chemical Formulas 1 to 3,

X ₁ , X ₂ and X ₃ are the same or different from each other, and each independently represent a tetravalent organic group derived from an alicyclic acid dianhydride or an aromatic acid dianhydride,

Y ₁ and Y ₂ are the same or different from each other, and each independently a divalent organic group derived from diamine,

Y ₃ is a divalent organic group derived from photodiamine selected from the group consisting of azobenzene photodiamine, cumarine photodiamine, chalcone photodiamine and cinnamate photodiamine. to be.

The first polymer and the second polymer may be present simply mixed, or may be present by copolymerization.

Hereinafter, each component will be described in detail.

First polymer

The first polymer includes a polyamic acid including a repeating unit represented by Formula 1, a polyimide including a repeating unit represented by Formula 2, or a combination thereof.

The polyamic acid including the repeating unit represented by Formula 1 may be synthesized from an acid dianhydride and a diamine. The method of preparing the polyamic acid by copolymerizing the acid dianhydride and the diamine may be applied without being limited to a method known to be usable for the synthesis of polyamic acid.

As said acid dianhydride, alicyclic acid dianhydride, aromatic acid dianhydride, or these can be used in mixture of 1 or more types. As said diamine, aromatic diamine, functional diamine, or these can be used in mixture of 1 or more types.

The alicyclic acid dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 5- (2,5-dioxotetrahydrofuryl) -3-methylcyclohexene-1,2- Dicarboxylic anhydride (DOCDA), bicyclooctene-2,3,5,6-tetracarboxylic dianhydride (BODA), 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA), 1 , 2,4,5-cyclohexanetetracarboxylic dianhydride (CHDA), 1,2,4-tricarboxy-3-methylcarboxy cyclopentane dianhydride, 1,2,3,4-tetracarboxy cyclopentane dianhydride Or may be used by mixing one or more thereof, but is not limited thereto.

The tetravalent organic group derived from the alicyclic acid dianhydride may include at least one of the functional groups represented by the following Chemical Formulas 4 to 8, but is not limited thereto.

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

In Chemical Formulas 4 to 8,

R ₁ is the same or different from each other, and each independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group,

n ₁ is an integer of 0 to 3,

R ₂ to R ₈ are the same or different from each other, and each independently a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl Qi.

The aromatic acid dianhydride may be pyromellitic dianhydride (PMDA), nonphthalic dianhydride (BPDA), oxydiphthalic dianhydride (ODPA), benzophenone tetracarboxylic dianhydride (BTDA), hexafluoroisopropylidene diphthalic acid The dianhydride (6-FDA), or a mixture of one or more thereof may be used, but is not limited thereto.

The tetravalent organic group derived from the aromatic acid dianhydride may include at least one of a functional group represented by the following Chemical Formula 9 and a functional group represented by the following Chemical Formula 10, but is not limited thereto.

[Formula 9]

[Formula 10]

In Chemical Formulas 9 and 10,

R ₉ and R ₁₀ are the same or different from each other, and each independently a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl Gigi,

R ₁₁ and R ₁₂ are the same or different from each other, and each independently represent a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group,

n ₂ and n ₃ are each independently an integer of 0 to 3,

A ₁ is a single bond, O, CO, substituted or unsubstituted C1 to C6 alkylene group (eg C (CF ₃ ) ₂ ), substituted or unsubstituted C3 to C30 cycloalkylene group, or substituted or unsubstituted C2 to C30 heterocycloalkylene group.

Examples of the aromatic diamine include paraphenylenediamine (p-PDA), 4,4-methylenedianiline (MDA), 4,4-oxydianiline (ODA), metabisaminophenoxydiphenylsulfone (m-BAPS), Parabisaminophenoxydiphenylsulfone (p-BAPS), 2,2-bisaminophenoxyphenylpropane (BAPP), 2,2-bisaminophenoxyphenylhexafluoropropane (HF-BAPP), 1,4- Diamino-2-methoxybenzene, VII, or a mixture of one or more thereof may be used, but is not limited thereto.

The divalent organic group derived from the aromatic diamine may include at least one of functional groups represented by the following Chemical Formulas 11 to 13, but is not limited thereto.

[Formula 11]

[Chemical Formula 12]

[Formula 13]

In Chemical Formulas 11 to 13,

R ₁₃ to R ₁₈ are the same or different from each other, and each independently represent a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, and The alkyl group, the aryl group and the heteroaryl group may further include selected from the group consisting of -O-, -COO-, -CONH-, -OCO- and combinations thereof,

A ₂ , A ₃ and A ₄ are the same or different from each other, and are each independently a single bond, O, SO ₂ or C (R ₁₀₀ ) (R ₁₀₁ ), such as C (CF ₃ ) ₂ , wherein R ₁₀₀ and R ₁₀₁ are the same or different from each other, and each independently a hydrogen atom or a substituted or unsubstituted C1 to C6 alkyl group,

n ₄ to n ₉ are each independently an integer of 0 to 4;

As the functional diamine, compounds represented by the following Chemical Formulas 14 to 16, or one or more thereof may be mixed and used. In this case, some of the polyamic acid will contain a divalent organic group derived from the functional diamine. By including the divalent organic group derived from the said functional diamine, adjustment of the pretilt angle of liquid crystal molecules in a liquid crystal aligning film can be made easy, and orientation can be improved.

[Formula 14]

In Chemical Formula 14,

R ₁₉ is hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group,

R ₂₀ are the same or different from each other, each independently represent a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group,

n ₁₀ is an integer of 0 to 3;

[Formula 15]

In Chemical Formula 15,

R ₂₁ , R ₂₂ and R ₂₃ are the same or different from each other, and each independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl Gigi,

A ₅ is a single bond, O, COO, CONH, OCO, or a substituted or unsubstituted C1 to C10 alkylene group,

R ₂₄ is hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group, and the alkyl group, the aryl group and the heteroaryl The group may further include selected from the group consisting of -O-, -COO-, -CONH-, -OCO-, and combinations thereof,

n ₁₁ is an integer of 0 or 3,

n ₁₂ and n ₁₃ are each independently an integer of 0 to 4;

[Formula 16]

In Chemical Formula 16,

R ₂₅ and R ₂₆ are the same or different from each other, and each independently represent a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group,

n ₁₄ and n ₁₅ are each independently an integer of 0 to 4,

R ₂₇ is hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group,

A ₆ and A ₇ are the same or different from each other, and each independently a single bond, O or COO,

A ₈ is a single bond, O, COO, CONH or OCO.

The polyimide containing the repeating unit represented by Formula 2 may be prepared by imidizing a polyamic acid including the repeating unit represented by Formula 1. Since a method of preparing polyimide by imidating polyamic acid is well known in the art, detailed description thereof will be omitted.

In the liquid crystal photoalignment agent, the first polymer may be included in an amount of about 0.01 wt% to about 15 wt%, and specifically, about 0.01 wt% to about 10 wt%. When the first polymer is included in the above range can improve the printability and vertical alignment.

In the liquid crystal photoalignment agent, the first polymer and the second polymer may be included in a weight ratio of about 0.01: 99.99 to about 99.99: 0.01, and specifically, may be included in a weight ratio of about 10:90 to about 90:10. . When the first polymer and the second polymer are included in the above range can improve the orientation stability.

Second polymer

The second polymer is a photopolymer including a polyimide including a repeating unit represented by Chemical Formula 3.

Polyimide containing a repeating unit represented by the formula (3) can be synthesized from acid dianhydride and photodiamine. Copolymerization and imidization of the acid dianhydride and the photodiamine to prepare a polyimide is well known in the art, so a detailed description thereof will be omitted.

As said acid dianhydride, alicyclic acid dianhydride, aromatic acid dianhydride, or these can be used in mixture of 1 or more types. As the photodiamine, azobenzene photodiamine, cinnamate photodiamine, chalcone photodiamine, coumarin photodiamine or one or more thereof may be mixed and used.

Unless otherwise described below, the contents of the alicyclic acid dianhydride and the aromatic acid dianhydride are the same as those described in the first polymer.

The cinnamate photodiamine may include a compound represented by the following Formula 17, but is not limited thereto.

[Formula 17]

In Chemical Formula 17,

R ₂₈ is an aromatic diamine group; Diamine groups including substituted or unsubstituted C1 to C24 linear or branched alkylene groups; Or a combination thereof,

The substituted alkylene group in R ₂₈ is an alkylene group in which a hydrogen atom is substituted with a halogen atom or a cyano group; One or more non-adjacent -CH ₂ -groups of the alkylene group substituted or unsubstituted arylene group, substituted or unsubstituted heteroarylene group, substituted or unsubstituted cycloalkylene group, substituted or unsubstituted heterocycloalkylene group,- O-, -CO-, -CO-O-, -O-CO-, -Si (CH ₃ ) ₂ -O-Si (CH ₃ ) _2- , -NR _102- , -NR ₁₀₃ -CO-,- _{CO-NR 104 -, -NR 105} -CO-O-, -O-CO-NR 106 -, -NR 107 -CO-NR 108 -, -CH = CH-, -C≡C-, -O-, or An alkylene group substituted with CO-O-; Or a combination thereof, an alkylene group, wherein R ₁₀₂ to R ₁₀₈ are the same or different from each other, and each independently hydrogen or a substituted or unsubstituted C 1 to C 6 alkyl group,

R ₂₉ are the same or different from each other, and each independently a substituted or unsubstituted C1 to C20 alkyl group; Substituted or unsubstituted C6 to C30 aryl group; Or a substituted or unsubstituted C2 to C30 heteroaryl group,

n ₁₆ is an integer of 0 to 4,

R ₃₀ and R ₃₁ are the same or different from each other, and each independently hydrogen, a halogen group, a cyano group, or a substituted or unsubstituted C1 to C12 alkyl group,

The alkyl group substituted in R ₃₀ and R ₃₁ is an alkyl group in which a hydrogen atom is substituted with a hetero atom or a cyano group; An alkyl group wherein at least one non-adjacent -CH ₂ -group of said alkyl group is substituted with -O-, -CO-O-, -O-CO-, or -CH = CH-; Or a combination of these alkyl groups,

R ₃₂ is hydrogen, a substituted or unsubstituted C 1 to C 30 alkyl group; Substituted or unsubstituted C7 to C30 alkylaryl group; A substituted or unsubstituted C3 to C30 alicyclic organic group, a substituted or unsubstituted pyrimidinyl group; Substituted or unsubstituted pyridinyl group; Substituted or unsubstituted thiophenyl group; Substituted or unsubstituted furanyl group; Substituted or unsubstituted naphthyl group; Or a substituted or unsubstituted phenyl group,

The alkyl group substituted in R ₃₂ is an alkyl group in which a hydrogen atom is substituted with a halogen group or a cyano group; An alkyl group wherein at least one non-adjacent -CH ₂ -group of said alkyl group is substituted with -O-, -CO-O-, -O-CO-, or -CH = CH-; Or a combination of these alkyl groups,

The substituted alkylaryl group in R ₃₂ is an alkyl in which at least one non-adjacent -CH ₂ -group of the alkylaryl group is substituted with -O-, -CO-O-, -O-CO-, or -CH = CH-. It is an aryl group.

The cinnamate photodiamine may specifically include a compound represented by Formula 18, but is not limited thereto.

[Formula 18]

In Chemical Formula 18,

R ₃₃ are the same or different from each other, and each independently a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group,

n ₁₇ is an integer of 0 to 3,

R ₃₄ is hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group.

The chalcone-based photodiamine may include a compound represented by the following Chemical Formula 19, but is not limited thereto.

[Formula 19]

In Chemical Formula 19,

R ₃₅ is an aromatic diamine group; Diamine groups substituted with a substituted or unsubstituted C1 to C24 linear or branched alkylene group; Or a combination thereof,

The substituted alkylene group at R ₃₅ is an alkylene group where a hydrogen atom is substituted with a halogen atom or a cyano group; One or more non-adjacent -CH ₂ -groups of the alkylene group substituted or unsubstituted arylene group, substituted or unsubstituted heteroarylene group, substituted or unsubstituted cycloalkylene group, substituted or unsubstituted heterocycloalkylene group,- O-, -CO-, -CO-O-, -O-CO-, -Si (CH 3) 2 -O-Si (CH 3) 2 -, -NR 109 -, -NR 110 -CO-, - _{CO-NR 111 -, -NR 112} -CO-O-, -O-CO-NR 113 -, -NR 114 -CO-NR 115, -CH = CH-, -C≡C-, or -O-CO An alkylene group substituted with -O-; Or a combination thereof, an alkylene group wherein R ₁₀₉ to R ₁₁₅ are the same or different from each other, and each independently hydrogen or a substituted or unsubstituted C 1 to C 6 alkyl group,

R ₃₉ and R ₄₀ are the same or different from each other, and each independently a substituted or unsubstituted C1 to C20 alkyl group; Substituted or unsubstituted C6 to C30 aryl group; Or a substituted or unsubstituted C2 to C30 heteroaryl group,

n ₁₈ and n ₁₉ are each independently an integer of 0 to 4,

R ₃₆ and R ₃₇ are the same or different from each other, and each independently hydrogen; Halogen group; Cyano group; Or a substituted or unsubstituted C1 to C12 alkyl group,

The substituted alkyl group in R ₃₆ and R ₃₇ is an alkyl group in which a hydrogen atom is substituted with a halogen atom or a cyano group; An alkyl group wherein at least one non-adjacent -CH ₂ -group of said alkyl group is substituted with -O-, -CO-O-, -O-CO-, or -CH = CH-; Or a combination of these alkyl groups,

R ₃₈ is hydrogen; A substituted or unsubstituted C1 to C30 alkyl group; Substituted or unsubstituted C7 to C30 alkylaryl group; A substituted or unsubstituted C3 to C30 alicyclic organic group, a substituted or unsubstituted pyrimidinyl group; Substituted or unsubstituted pyridinyl group; Substituted or unsubstituted thiophenyl group; Substituted or unsubstituted furanyl group; Substituted or unsubstituted naphthyl group; Or a substituted or unsubstituted phenyl group,

The substituted alkyl group in R ₃₈ is an alkyl group where a hydrogen atom is substituted with a halogen group or a cyano group with a substituent; An alkyl group wherein at least one non-adjacent -CH ₂ -group of said alkyl group is substituted with -O-, -CO-O-, -O-CO-, or -CH = CH-; Or a combination of these alkyl groups,

The substituted alkylaryl group in R ₃₈ is an alkyl in which at least one non-adjacent -CH ₂ -group of the alkylaryl group is substituted with -O-, -CO-O-, -O-CO-, or -CH = CH-. It is an aryl group.

The coumarin-based photodiamine may include a compound represented by the following Formula 20, but is not limited thereto.

[Formula 20]

In Chemical Formula 20,

R ₄₁ is an aromatic diamine group, a diamine group substituted with a substituted or unsubstituted C1 to C24 linear or branched alkylene group, or a combination thereof,

The substituted alkylene group in R ₄₁ is an alkylene group in which a hydrogen atom is substituted with a halogen atom or a cyano group; One or more non-adjacent -CH ₂ -groups of the alkylene group substituted or unsubstituted arylene group, substituted or unsubstituted heteroarylene group, substituted or unsubstituted cycloalkylene group, substituted or unsubstituted heterocycloalkylene group,- O-, -CO-, -CO-O-, -O-CO-, -Si (CH 3) 2 -O-Si (CH 3) 2 -, -NR 116 -, -NR 117 -CO-, - _{CO-NR 118 -, -NR 119} -CO-O-, -O-CO-NR 120 -, -NR 121 -CO-NR 122 -, -CH = CH-, -C≡C-, -O-, or An alkylene group substituted with CO-O-; Or a combination thereof, an alkylene group wherein R ₁₁₆ to R ₁₂₂ are the same or different from each other, and each independently hydrogen or a substituted or unsubstituted C 1 to C 6 alkyl group,

R ₄₄ are the same or different from each other, and each independently a substituted or unsubstituted C1 to C20 alkyl group; Substituted or unsubstituted C6 to C30 aryl group; Or a substituted or unsubstituted C2 to C30 heteroaryl group,

n ₂₀ is an integer from 0 to 4,

R ₄₂ and R ₄₃ are the same or different from each other, and each independently hydrogen; Halogen group; Cyano group; Or a substituted or unsubstituted C1 to C12 alkyl group,

The alkyl group substituted in R ₄₂ and R ₄₃ is an alkyl group in which a hydrogen atom is substituted with a halogen group or a cyano group; An alkyl group wherein at least one non-adjacent -CH ₂ -group of said alkyl group is substituted with -O-, -CO-O-, -O-CO-, or -CH = CH-; Or an alkyl group thereof.

In the liquid crystal photoalignment agent, the second polymer may be included in an amount of about 0.01 wt% to about 15 wt%, and specifically, about 0.01 wt% to about 10 wt%. When the second polymer is included in the above range can improve the orientation stability.

In the liquid crystal photoalignment agent, the first polymer and the second polymer may be included in a weight ratio of about 0.01: 99.99 to about 99.99: 0.01, and specifically, may be included in a weight ratio of about 10:90 to about 90:10. . In this case, the effects may be as described above.

menstruum

The solvent includes a solvent suitable for dissolving the first polymer and the second polymer, and also includes monoethylene glycol dimethyl ether (DMG) and dipropylene glycol dimethyl ether (DMFDG). As a result, the liquid crystal photoalignment agent may have excellent spreadability and adhesiveness with the substrate, and may form a uniform coating film even when process conditions, such as drying temperature or firing temperature, are changed.

The monoethylene glycol dimethyl ether and the dipropylene glycol dimethyl ether may be included in a weight ratio of 10:90 to 90:10, and specifically, may be included in a weight ratio of 10:70 Pa to 70:10 Pa. In addition, the monoethylene glycol dimethyl ether and dipropylene glycol dimethyl ether may be included in an amount of about 5 to about 80% by weight, specifically, about 20 to about 70% by weight, based on the total amount of the solvent. . When the liquid crystal photo-alignment agent includes monoethylene glycol dimethyl ether and dipropylene glycol dimethyl ether in the above range, spreadability and adhesion with the substrate can be improved, and coating film uniformity is good even with changes in process conditions, for example, changes in drying temperature. Properties can be maintained, printability can be easily improved, and the first polymer and the second polymer can be easily dissolved.

Examples of suitable solvents for dissolving the first polymer and the second polymer include N-methyl-2-pyrrolidone; N, N-dimethyl acetamide; N, N-dimethyl formamide; Dimethyl sulfoxide; γ-butyrolactone; Tetrahydrofuran (THF); And phenolic solvents such as meta cresol, phenol, and halogenated phenol, but are not limited thereto.

The solvent may further include 2-butyl cellosolve (2-BC), thereby improving printability. In this case, the 2-butyl cellosolve may be included in an amount of about 1 to about 50 wt%, and specifically, about 10 to about 40 wt%, based on the total amount of the solvent including 2-butyl cellosolve. When 2-butyl cellosolve is included in the above range, the printability can be easily improved. 　

In addition, the solvent may further include a poor solvent alcohols, ketones, esters, ethers, hydrocarbons, or halogenated hydrocarbons in an appropriate ratio within the limit of the precipitation of the soluble polyimide polymer. The poor solvents may lower the surface energy of the liquid crystal aligning agent to improve spreadability and flatness during coating.

The poor solvent may be included in an amount of about 1 kPa to about 90 wt%, specifically about 1 to about 70 wt%, based on the total amount of the solvent including the poor solvent.

Specific examples of the poor solvent include methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl Acetate, diethyl oxalate, malonic ester, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol phenyl ether, ethylene glycol phenylmethyl ether, ethylene glycol phenylethyl ether, diethylene glycol dimethyl ether, Diethylene glycol ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, 4- Hydroxy-4-meth Methyl-2-pentanone, 2-hydroxy ethyl propionate, 2-hydroxy-2-methyl propionate, ethyl ethoxy acetate, hydroxy ethyl acetate, 2-hydroxy-3-methyl butanoate, 3-meth Methyl oxypropionate, ethyl 3-methoxy propionate, ethyl 3-ethoxy propionate, methyl 3-ethoxy propionate, methyl methoxy butanol, ethyl methoxy butanol, methyl ethoxy butanol, ethyl ethoxy butanol, tetrahydrofuran, dichloro Methane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, or a mixture of one or more thereof can be used. have. 　

The content of the solvent in the liquid crystal photo-alignment agent is not particularly limited, but may be used so that the content of solids in the liquid crystal photo-alignment agent is about 0.01 kPa to about 15 wt%, specifically, the content of solids is about 3 to about 15 It may be used to the weight percent, and more specifically may be used so that the content of the solid content is about 5 to about 10% by weight. When the content of solids is within the above range, the uniformity of the film can be properly maintained and the appropriate viscosity can be maintained by being less affected by the contamination of the substrate surface at the time of printing, thereby preventing the uniformity of the film due to the high viscosity at the time of printing. Can exhibit an appropriate transmittance.

The liquid crystal photoalignment agent may have a viscosity of about 3 to about 30 cps, specifically, may have a viscosity of about 5 to about 25 cps. 　 When the viscosity of a liquid crystal photoalignment agent is in the said range, coating film uniformity and applicability | paintability can be improved.

Other additives

Liquid crystal photoalignment agent according to an aspect of the present invention may further include other additives.

The other additives include epoxy compounds. The epoxy compound is used to improve reliability and electro-optic properties, and the epoxy compound may use one or more epoxy compounds including 2 to 8 epoxy groups, specifically, 2 to 4 epoxy groups.

The epoxy compound may be included in an amount of about 0.1 kPa to about 50 parts by weight based on 100 parts by weight of the sum of the first polymer and the second polymer, and specifically, about 1 to about 30 parts by weight. When the epoxy compound is included in the above range, it is possible to easily improve the reliability and electro-optical properties, while exhibiting proper printability and flatness when applied to the substrate.

Examples of the epoxy compound may include a compound represented by the following Formula 21, but is not limited thereto.

[Formula 21]

In Chemical Formula 21,

A ₉ is a substituted or unsubstituted C6 to C12 aromatic organic group, or a substituted or unsubstituted divalent C6 to C12 alicyclic organic group, or a substituted or unsubstituted divalent C6 to C12 aliphatic organic group such as substituted or unsubstituted It is a ring C1-C6 alkylene group.

Specific examples of the epoxy compound include N, N, N ', N'-tetraglycidyl-4,4'-diaminophenylmethane (TGDDM), N, N, N', N'-tetraglycidyl- 4,4'-diaminophenylethane, N, N, N ', N'-tetraglycidyl-4,4'-diaminophenylpropane, N, N, N', N'-tetraglycidyl- 4,4'-diaminophenylbutane, N, N, N ', N'- tetraglycidyl-4,4'-diaminobenzene, ethyleneglycol diglycidyl ether, polyethylene glycol diglycidyl ether, Propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin digly Cydyl ether, 2,2-dibromoneopentylglycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ', N'- Tetraglycidyl-1,4-phenylenediamine, N, N, N ', N'-tetraglycidyl-m-xylenediamine, N, N, N', N'-tetraglycidyl- 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2-bis [4- (N, N-diglycidyl-4-aminophenoxy) phenyl] propane, N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, 1,3-bis (N, N Diglycidylaminomethyl) benzene, and the like, but is not limited thereto.

Moreover, in order to improve printability, a suitable surfactant or coupling agent may be further used as an additive.

Liquid crystal photoalignment film according to another aspect of the present invention is prepared using the liquid crystal photoalignment agent.

The liquid crystal photo-alignment film can be formed by applying a liquid crystal photo-alignment agent to a substrate. Examples of the method for applying the liquid crystal photo-alignment agent to the substrate include a spin coat method, a flexographic printing method and an inkjet method. Among them, the flexographic printing method is excellent in uniformity of the formed coating film and can be easily enlarged, and therefore, it can be generally used.

As the substrate, any substrate having high transparency can be used without particular limitation, and a plastic substrate such as a glass substrate or an acrylic substrate or a polycarbonate substrate can be used. In addition, using a substrate on which an indium-tin oxide (ITO) electrode or the like for driving a liquid crystal is used, the manufacturing process may be simplified.

The liquid crystal photo-alignment agent is uniformly applied to the substrate in order to increase the uniformity of the coating film, then to a temperature of room temperature to about 200 ℃, specifically to a temperature of about 30 ℃ to about 150 ℃, more specifically about 40 ℃ The temporary drying may be carried out at a temperature of from about 120 ° C. for about 1 minute to about 100 minutes. By adjusting the volatilization of each component of the liquid crystal aligning agent through the temporary drying, a uniform and uneven coating film can be obtained.

Thereafter, the liquid crystal photo-alignment layer may be formed by evaporating the solvent by baking for about 5 minutes to about 300 minutes at a temperature of about 80 ° C to about 300 ° C, specifically about 120 ° C to about 280 ° C. .

The liquid crystal photoalignment film formed by the above method may be used in a liquid crystal display device without uniaxial alignment treatment by polarized ultraviolet irradiation or in some applications such as a vertical alignment layer.

The liquid crystal photoalignment film according to the aspect of the present invention may be exposed to light for about 0.1 minutes to about 180 minutes at an energy of about 10 mJ to about 5,000 mJ to perform uniaxial alignment treatment. When the uniaxial orientation treatment is performed while reducing the exposure intensity as described above, the double bond included in the second polymer can be easily removed.

According to another aspect of the invention provides a liquid crystal display device comprising the liquid crystal photo-alignment film.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the following Examples and Comparative Examples are for illustrative purposes only and are not intended to limit the present invention.

Example

( Manufacturing example One: Of polyamic acid (PAA-1)  Produce)

A functional diamine 3,5-diaminophenyldecyl succinimide represented by the formula (22) with 0.7 mol of paraphenylenediamine passing through nitrogen in a four-necked flask equipped with a stirrer, a thermostat, a nitrogen gas injection device, a cooler and a cooler. 0.3 mmol of (3,5-Diaminophenyldecyl succinimide) was added, and N-methyl-2-pyrrolidone (NMP) was added thereto to prepare a mixed solution.

[Formula 22]

1.0 mmol of 1,2,3,4-cyclobutanetetracarboxylic dianhydride in solid state was added to the mixed solution, followed by vigorous stirring. At this time, the solid content is 30% by weight, the reaction was carried out for 10 hours while maintaining the temperature at 30 ℃ ~ 50 ℃ to prepare a polyamic acid resin. To the prepared polyamic acid resin was added a mixed organic solvent of N-methyl-2-pyrrolidone and γ-butyrolactone as organic solvents, and stirred at room temperature for 24 hours to prepare a polyamic acid (PAA-1) solution. .

( Manufacturing example 2: polyimide ( SPI -1) manufacturing)

0.8 mol of paraphenylenediamine and 0.2 mmol of 3,5-diaminophenyldecyl succinimide represented by the formula (22) were passed through nitrogen in a four-necked flask equipped with a stirrer, a temperature controller, a nitrogen gas injection device, and a cooler. N-methyl-2-pyrrolidone was added thereto to prepare a mixed solution.

1.0 mmol of 1,2,3,4-cyclobutanetetracarboxylic dianhydride in solid state was added to the mixed solution, followed by vigorous stirring. The solid content at this time is 20% by weight, the reaction was carried out for 10 hours while maintaining a temperature of 30 ℃ 50 50 ℃ to prepare a polyamic acid solution.

3.0 mol of acetic anhydride and 5.0 mol of pyridine were added to the prepared polyamic acid solution, and the temperature was raised to 80 ° C., followed by reaction for 6 hours, and the catalyst and solvent were removed by vacuum distillation to obtain a 30% soluble poly Mid resin was prepared.

To the prepared soluble polyimide resin was added a mixed organic solvent of N-methyl-2-pyrrolidone and γ-butyrolactone as organic solvents, and stirred at room temperature for 24 hours to prepare a soluble polyimide (SPI-1) resin. Prepared.

( Manufacturing example 3: polyimide ( PSPI -1) manufacturing)

A 4-necked flask equipped with a stirrer, a thermostat, a nitrogen gas injector, and a cooler was charged with 0.5 mole of paraphenylenediamine while passing nitrogen under darkroom conditions. 0.5 mol of carbonyl-vinyl) -phenyl ester was added thereto, and N-methyl-2-pyrrolidone was added thereto to prepare a mixed solution.

(23)

1.0 mmol of 1,2,3,4-cyclobutanetetracarboxylic dianhydride in solid state was added to the mixed solution, followed by vigorous stirring. At this time, the solid content is 20% by weight, the reaction was carried out for 24 hours while maintaining the temperature at 30 ℃ 80 80 ℃ to prepare a polyamic acid solution.

3.0 mol of acetic anhydride and 5.0 mol of pyridine were added to the prepared polyamic acid solution, and the temperature was raised to 80 ° C., followed by reaction for 6 hours. The catalyst and the solvent were removed by vacuum distillation to obtain a 30% solid soluble polyimide. Was prepared.

To the soluble polyimide, a mixed organic solvent of N-methyl-2-pyrrolidone 인 and γ-butyrolactone, which are organic solvents, was added to the soluble polyimide, and stirred at room temperature for 24 hours to soluble photo-oriented polyimide (PSPI-1) resin. Was prepared.

(Liquid crystal Photocolon  Produce)

( Example  One)

To 30 g of the polyamic acid (PAA-1) solution of 30% by weight of solids obtained in Preparation Example 1, 30 g of the polyimide (PSPI-1) solution of 20% by weight of solids obtained in Preparation Example 3 was added, followed by? -Butyrolactone (GBL). 12 µg, 14 µg of monoethylene glycol dimethyl ether (DMG) and 124 g of dipropylene glycol dimethyl ether (DMFDG) were added, stirred at room temperature for 24 hours, diluted with a filter having a particle size of 0.1 µm, and then solid content of 8 weight. % And a liquid crystal photoalignment agent having a viscosity of 20 cps were obtained (hereinafter referred to as BSPI-1).

( Example  2)

To 70 g of a polyamic acid (PAA-1) solution of 30% by weight solids obtained in Preparation Example 1, 30 g of a polyimide (PSPI-1) solution of 20% by weight of solids obtained in Preparation Example 3 was added, followed by? -Butyrolactone. 12 g, 46 g of 2-butyl cellosolve (2-BC), 10 g of monoethylene glycol dimethyl ether (DMG), and 82 g of dipropylene glycol dimethyl ether (DMFDG) were added, followed by stirring and diluting at room temperature for 24 hours. The resultant was filtered through a filter having a particle size of 0.1 μm to obtain a liquid crystal photo-alignment agent having a solid content of 8% by weight and a viscosity of 20 cps (hereinafter referred to as BSPI-2).

( Example  3)

To 30 g of a polyamic acid (PAA-1) solution of 30% by weight of solid content obtained in Preparation Example 1, 30 g of a polyimide (PSPI-1) solution of 20% by weight of solid content obtained in Preparation Example 3 was added, and then gamma -butyrolactone. 12 g of monoethylene glycol dimethyl ether (DMG) and 14 g of dipropylene glycol dimethyl ether (DMFDG) were added, stirred at room temperature for 24 hours, diluted with a filter having a particle size of 0.1 μm, and then solid content of 8 wt. % And a liquid crystal photoalignment agent having a viscosity of 20 cps were obtained (hereinafter referred to as BSPI-3).

( Example  4)

To 70 g of a polyamic acid (PAA-1) solution of 30% by weight solids obtained in Preparation Example 1, 30 g of a polyimide (PSPI-1) solution of 20% by weight of solids obtained in Preparation Example 3 was added, followed by? -Butyrolactone. 12 g, 2-butyl cellosolve 46 g, monoethylene glycol dimethyl ether (DMG) 82 gg, and dipropylene glycol dimethyl ether (DMFDG) 10 g were added thereto, stirred at room temperature for 24 hours, and then diluted to a particle diameter of 0.1 탆. Filtration with a filter yielded a liquid crystal photo-alignment agent having a solid content of 8% by weight and a viscosity of 20 cps (hereinafter referred to as BSPI-4).

( Example  5)

After adding 30 g of the polyimide (PSPI-1) solution of 20 weight% of solid content obtained in manufacture example 3 to 70 g of the polyimide (SPI-1) solution of 20 weight% of solid content obtained by manufacture example 2, gamma-butyrolactone 12 g, 124 모노 monoethylene glycol dimethyl ether (DMG) and 14 g of dipropylene glycol dimethyl ether (DMFDG) were added, stirred at room temperature for 24 hours, followed by dilution, followed by filtration with a filter having a particle size of 0.1 μm. % And a liquid crystal photoalignment agent having a viscosity of 20 cps were obtained (hereinafter referred to as BSPI-5).

( Example  6)

To 70 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2, 30 g of a polyimide (PSPI-1) solution of 20% by weight of solids obtained in Preparation Example 3 was added, followed by γ-butyrolactone. 12 g, 2-butyl cellosolve 46 g, monoethylene glycol dimethyl ether (DMG) 10 g and dipropylene glycol dimethyl ether (DMFDG) 82 g were added, stirred at room temperature for 24 hours, followed by dilution for a filter having a particle size of 0.1 μm. Filtration was performed to obtain a liquid crystal photo-alignment agent having a solid content of 8% by weight and a viscosity of 20 cps (hereinafter referred to as BSPI-6).

( Example  7)

To 70 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2, 30 g of a polyimide (PSPI-1) solution of 20% by weight of solids obtained in Preparation Example 3 was added, followed by γ-butyrolactone. 12 µg, 14 µg of monoethylene glycol dimethyl ether (DMG) and 124 g of dipropylene glycol dimethyl ether (DMFDG) were added, stirred at room temperature for 24 hours, and diluted with a filter having a particle size of 0.1 µm. And a liquid crystal photo-alignment agent having a viscosity of 20 cps were obtained (hereinafter referred to as BSPI-7).

( Example  8)

To 70 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2, 30 g of a polyimide (PSPI-1) solution of 20% by weight of solids obtained in Preparation Example 3 was added, followed by γ-butyrolactone. 12 μg, 2-butyl cellosolve, 46 g of monoethylene glycol dimethyl ether (DMG), and 10 g of dipropylene glycol dimethyl ether (DMFDG) were added, stirred at room temperature for 24 hours, and diluted with a filter having a particle size of 0.1 μm. Filtration was performed to obtain a liquid crystal photo-alignment agent having a solid content of 8% by weight and a viscosity of 20 cps (hereinafter referred to as BSPI-8).

( Example  9)

20 g of a polyamic acid (PAA-1) solution of 30% by weight of solids obtained in Preparation Example 1, 50 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2 and 20 weight of solids obtained in Preparation Example 3 After adding 30 g of% polyimide (PSPI-1) solution, 12 g of γ-butyrolactone, 124 g of monoethylene glycol dimethyl ether (DMG) and 14 g of dipropylene glycol dimethyl ether (DMFDG) were added thereto, and room temperature. After 24 hours of stirring and dilution, the resultant was filtered through a filter having a particle size of 0.1 μm to obtain a liquid crystal photo-alignment agent having a solid content of 8 wt% and a viscosity of 20 cps (hereinafter referred to as BSPI-9).

( Example  10)

20 g of a polyamic acid (PAA-1) solution of 30% by weight of solids obtained in Preparation Example 1, 50 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2 and 20 weight of solids obtained in Preparation Example 3 After adding 30 g of% polyimide (PSPI-1) solution, 12 g of γ-butyrolactone, 46 g of 2-butyl cellosolve, 10 g of monoethylene glycol dimethyl ether (DMG), and dipropylene glycol dimethyl ether (DMFDG) ) 82 g were added, stirred at room temperature for 24 hours, followed by dilution, followed by filtration through a filter having a particle size of 0.1 μm to obtain a liquid crystal photo-alignment agent having a solid content of 8 wt% and a viscosity of 20 cps (hereinafter referred to as BSPI-10).

( Example  11)

20 g of a polyamic acid (PAA-1) solution of 30% by weight of solids obtained in Preparation Example 1, 50 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2 and 20 weight of solids obtained in Preparation Example 3 After adding 30 g of% polyimide (PSPI-1) solution, 12 g of γ-butyrolactone, 14 g of g-monoethylene glycol dimethyl ether (DMG), and 124 g of dipropylene glycol dimethyl ether (DMFDG) were added thereto. After 24 hours of stirring and dilution, the resultant was filtered through a filter having a particle size of 0.1 μm to obtain a liquid crystal photo-alignment agent having a solid content of 8 wt% and a viscosity of 20 cps (hereinafter referred to as BSPI-11).

(Example 12)

20 g of a polyamic acid (PAA-1) solution of 30% by weight of solids obtained in Preparation Example 1, 50 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2 and 20 weight of solids obtained in Preparation Example 3 After adding 30 g of% polyimide (PSPI-1) solution, 12 g of γ-butyrolactone, 46 g of 2-butyl cellosolve, 82 g of monoethylene glycol dimethyl ether (DMG), and dipropylene glycol dimethyl ether (DMFDG) ) 10 g was added, stirred at room temperature for 24 hours, diluted, and filtered through a filter having a particle size of 0.1 μm to obtain a liquid crystal photo-alignment agent having a solid content of 8 wt% and a viscosity of 20 cps (hereinafter referred to as BSPI-12).

( Comparative example  One)

To 70 g of a polyamic acid (PAA-1) solution of 30% by weight of solids obtained in Preparation Example 1, 30 g of a polyimide (PSPI-1) solution of 20% by weight of solids obtained in Preparation Example 3 was added to γ-butyrolactone. 12 g and 138 g of monoethylene glycol dimethyl ether (DMG) were added thereto, and stirred and diluted at room temperature for 24 hours, followed by filtration through a filter having a particle size of 0.1 μm. Hereinafter referred to as BSPI-13).

( Comparative example  2)

After adding 70 g of the polyimide (SPI-1) solution of 20% by weight of solid content obtained in Preparation Example 2 and 30 g of the polyimide (PSPI-1) solution of 20% by weight of solid content obtained in Preparation Example 3, gamma -butyrolactone was added. 12 g and 138 g of monoethylene glycol dimethyl ether (DMG) were added thereto, and stirred and diluted at room temperature for 24 hours, followed by filtration through a filter having a particle size of 0.1 μm. Hereinafter referred to as BSPI-14).

( Comparative example  3)

20 g of a polyamic acid (PAA-1) solution of 30% by weight of solids obtained in Preparation Example 1, 50 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2 and 20 weight of solids obtained in Preparation Example 3 30 g of% polyimide (PSPI-1) solution was added, followed by 12 g of γ-butyrolactone and 138 g of monoethylene glycol dimethyl ether (DMG), followed by stirring at room temperature for 24 hours. The product was filtered through a filter to obtain a liquid crystal photo-alignment agent having a solid content of 8% by weight and a viscosity of 20 cps (hereinafter referred to as BSPI-15).

( Comparative example  4)

After adding 70 g of a polyamic acid (PAA-1) solution of 30% by weight of solid content obtained in Preparation Example 1 and 30 g of a polyimide (PSPI-1) solution of 20% by weight of solid content obtained in Preparation Example 3, gamma -butyrolactone was added. 12 g and 138 g of dipropylene glycol dimethyl ether (DMFDG) were added thereto, and stirred and diluted at room temperature for 24 hours, followed by filtration through a filter having a particle diameter of 0.1 μm, to obtain a liquid crystal photo-alignment agent having a solid content of 8% by weight and a viscosity of 20 cps. Hereinafter referred to as BSPI-16).

( Comparative example  5)

After adding 70 g of the polyimide (SPI-1) solution of 20% by weight of solid content obtained in Preparation Example 2 and 30 g of the polyimide (PSPI-1) solution of 20% by weight of solid content obtained in Preparation Example 3, gamma -butyrolactone was added. 12 g and 138 g of dipropylene glycol dimethyl ether (DMFDG) were added thereto, and stirred and diluted at room temperature for 24 hours, followed by filtration through a filter having a particle diameter of 0.1 μm, to obtain a liquid crystal photo-alignment agent having a solid content of 8% by weight and a viscosity of 20 cps. Hereinafter referred to as BSPI-17).

( Comparative example  6)

20 g of a polyamic acid (PAA-1) solution of 30% by weight of solids obtained in Preparation Example 1, 50 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2 and 20 weight of solids obtained in Preparation Example 3 30 g of% polyimide (PSPI-1) solution was added, 12 g of γ-butyrolactone and 138 g of dipropylene glycol dimethyl ether (DMFDG) were added thereto, followed by stirring and diluting at room temperature for 24 hours, followed by particle size of 0.1 μm. The product was filtered through a filter to obtain a liquid crystal photo-alignment agent having a solid content of 8% by weight and a viscosity of 20 cps (hereinafter referred to as BSPI-18).

( Comparative example  7)

20 g of a polyamic acid (PAA-1) solution of 30% by weight of solids obtained in Preparation Example 1, 50 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2 and 20 weight of solids obtained in Preparation Example 3 After adding 30 g of% polyimide (PSPI-1) solution, 138 g of γ-butyrolactone and 12 g of dipropylene glycol dimethyl ether (DMFDG) were added, followed by stirring and diluting at room temperature for 24 hours, followed by particle size of 0.1 μm. Was filtered through a filter of to obtain a liquid crystal photo-alignment agent having a solid content of 8% by weight and a viscosity of 20 cps (hereinafter referred to as BSPI-19).

( Comparative example  8)

20 g of a polyamic acid (PAA-1) solution of 30% by weight of solids obtained in Preparation Example 1, 50 g of a polyimide (SPI-1) solution of 20% by weight of solids obtained in Preparation Example 2 and 20 weight of solids obtained in Preparation Example 3 After adding 30 g of% polyimide (PSPI-1) solution, 138 g of γ-butyrolactone and 12 g of monoethylene glycol dimethyl ether (DMG) were added, followed by stirring and diluting at room temperature for 24 hours. The product was filtered through a filter to obtain a liquid crystal photo-alignment agent having a solid content of 8% by weight and a viscosity of 20 cps (hereinafter referred to as BSPI-20).

Spreadability Assessment

On the cleaned glass substrate with indium-tin oxide (ITO), 부착 the liquid crystal photo-alignment agent prepared in Examples 1 to 12, and Comparative Examples 1 to 8 were respectively used in a microscanner. After dropping each by 0.001 ml, it was left for 10 to 30 minutes and the spread was observed using an electron microscope (MX-50, Olympus). Based on the observation, the spread distance was measured based on the central axis of the dropped solution, and the spreadability was evaluated according to the following criteria, and the results are shown in Table 1 below.

Spreadability Evaluation Criteria ( Dispense distance, in mm, from the central axis of the dropped solution)

Good: greater than 10 mm

Usually: 5 mm or more and 10 mm or less

Poor: less than 5 mm

Coating uniformity evaluation

On the cleaned glass substrate with indium-tin oxide (ITO), the liquid crystal photo-alignment agents prepared in Examples 1 to 12 and Comparative Examples 1 to 8 were plated using an alignment film printer (CZ 200, Nakan Corporation). After flexo printing, the printed substrate was allowed to stand for 2 to 5 minutes on a hot plate at 50 ° C., 70 ° C. and 90 ° C., respectively, to temporarily dry the coating film. The film surface after the drying was visually observed and the film thickness deviation was measured by an electron microscope, and the coating film uniformity was evaluated according to the following criteria, and the results are shown in Table 1.

In addition, after the substrate was temporarily dried, the substrate was baked for 30 minutes on a hot plate at 200 ° C. and 230 ° C., and then exposed at an energy of 100 mJ to prepare a substrate with a liquid crystal photoalignment film. While visually observing the surface of the liquid crystal photoalignment film attached to the substrate, the film thickness deviation was measured by an electron microscope (MX-50, Olympus, Inc.), and the coating film uniformity was evaluated according to the following criteria. 1 is shown.

Evaluation criteria for film uniformity (deviation of film thickness, unit: μm)

Good: less than 0.005 μm

Usually: 0.005 μm or more and 0.01 μm or less

Poor: greater than 0.01 μm

LCD Photo-alignment film  Electrical property evaluation

Electrical and optical properties of the liquid crystal photoalignment film were evaluated by measuring the voltage holding ratio and the residual DC voltage using a liquid crystal cell having a 4.75 μm cell gap.

The voltage retention ratio refers to the extent to which the liquid crystal layer in the state of floating with the external power source maintains the charged voltage during the non-selection period in the active driving type TFT-LCD, and a value close to 100% is ideal.

The residual DC voltage refers to a voltage applied to the liquid crystal layer even when no impurities are applied to the alignment layer, and thus no impurities are applied to the alignment layer. As a method of measuring the residual DC voltage, a method using flicker and a method using a capacitance change curve (C-V) of the liquid crystal layer according to DC voltage are common.

The electrical and optical properties of the liquid crystal photoalignment film using the liquid crystal cell are shown in Table 1 below.

TABLE 1

LCD
Photo-alignment

Spreadability Temporary drying
According to temperature
Coating Uniformity Firing
According to temperature
Coating Uniformity
Voltage
Conservation rate
(%)
Residual DC voltage
(by CV)
(mV) 50 ℃ 70 ℃ 90 ° C 200 ℃ 230 ℃ Example 1 BSPI-1 Good Good Good Good Good Good 98.6 104 Example 2 BSPI-2 Good Good Good Good Good Good 98.7 89 Example 3 BSPI-3 Good Good Good Good Good Good 98.7 107 Example 4 BSPI-4 Good Good Good Good Good Good 98.7 108 Example 5 BSPI-5 Good Good Good Good Good Good 98.5 101 Example 6 BSPI-6 Good Good Good Good Good Good 98.6 98 Example 7 BSPI-7 Good Good Good Good Good Good 98.8 92 Example 8 BSPI-8 Good Good Good Good Good Good 98.6 89 Example 9 BSPI-9 Good Good Good Good Good Good 98.9 99 Example 10 BSPI-10 Good Good Good Good Good Good 98.7 105 Example 11 BSPI-11 Good Good Good Good Good Good 98.7 103 Example 12 BSPI-12 Good Good Good Good Good Good 98.6 108 Comparative Example 1 BSPI-13 Bad Bad Bad Good Bad Bad 98.8 111 Comparative Example 2 BSPI-14 Bad Bad Bad Good Bad Bad 98.7 112 Comparative Example 3 BSPI-15 Bad Bad Bad Good Bad Bad 98.6 122 Comparative Example 4 BSPI-16 Bad Bad Bad Good Bad Bad 98.5 100 Comparative Example 5 BSPI-17 Bad Bad Bad Good Bad Bad 98.5 121 Comparative Example 6 BSPI-18 Bad Bad Bad Good Bad Bad 98.6 118 Comparative Example 7 BSPI-19 Bad Bad Bad Good Bad Bad 98.5 109 Comparative Example 8 BSPI-20 Bad Bad Bad Good Bad Bad 98.5 110

As shown in Table 1, the liquid crystal photoalignment agent prepared in Examples 1 to 12 was excellent in spreadability, the printability is good irrespective of the temporary drying temperature to the firing temperature to produce a liquid crystal photoalignment film having excellent coating film uniformity. It can be seen that it can be used to. On the other hand, the liquid crystal photo-alignment agent prepared in Comparative Examples 1 to 8 is poor in the spreadability and coating film uniformity may be limited to use in manufacturing the liquid crystal photo-alignment layer.

In addition, when comparing the electrical properties of the liquid crystal photoalignment film when the liquid crystal photoalignment agent prepared in Examples 1 to 12 and the liquid crystal photoalignment agent prepared in Comparative Examples 1 to 8 were used, It can be seen that the case where the liquid crystal photo-alignment agent is used shows better or equivalent level of voltage retention and the residual DC voltage than when the liquid crystal photo-alignment agent prepared in Comparative Examples 1 to 8 is used.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

Claims (12)

A first polymer including a polyamic acid including a repeating unit represented by Formula 1, a polyimide including a repeating unit represented by Formula 2, or a combination thereof; A second polymer comprising a polyimide including a repeating unit represented by Formula 3 below; And Solvents containing monoethylene glycol dimethyl ether (DMG) and dipropylene glycol dimethyl ether (DMFDG) Liquid crystal photoalignment agent comprising: [Formula 1]

[Formula 2]

(3)

In Chemical Formulas 1 to 3, X ₁ , X ₂ and X ₃ are the same or different from each other, and each independently represent a tetravalent organic group derived from an alicyclic acid dianhydride or an aromatic acid dianhydride, Y ₁ and Y ₂ are the same or different from each other, and each independently a divalent organic group derived from diamine, Y ₃ is a divalent organic group derived from photodiamine selected from the group consisting of azobenzene photodiamine, cumarine photodiamine, chalcone photodiamine and cinnamate photodiamine. to be. The method of claim 1, The weight ratio of the monoethylene glycol dimethyl ether and dipropylene glycol dimethyl ether is 10:90 to 90:10 liquid crystal photo-alignment agent. The method of claim 1, The monoethylene glycol dimethyl ether and dipropylene glycol dimethyl ether is a liquid crystal photo-alignment agent comprising a sum of 5 to 80% by weight based on the total amount of the solvent. The method of claim 1, Wherein said solvent further comprises 2-butyl cellosolve (2-BC). The method of claim 4, wherein The 2-butyl cellosolve (2-BC) is a liquid crystal photo-alignment agent containing 1 to 50% by weight based on the total amount of the solvent containing 2-butyl cellosolve. The method of claim 1, A liquid crystal photoalignment agent comprising 0.01 to 15% by weight of the first polymer, 0.01 to 15% by weight of the second polymer, and 30 to 99.98% by weight of the solvent. The method of claim 1, Liquid crystal photo-alignment agent comprising the first polymer and the second polymer in a weight ratio of 0.01: 99.99 to 99.99: 0.01. The method of claim 1, The liquid crystal photoalignment agent of 0.1 to 50 parts by weight based on 100 parts by weight of the sum of the first polymer and the second polymer. The method of claim 1, The liquid crystal photoalignment agent having a solid content of 0.01 to 15% by weight. The method of claim 1, The liquid crystal photoalignment agent having a viscosity of 3 to 30 cps. A liquid crystal photoalignment film prepared by applying the liquid crystal photoalignment agent according to any one of claims 1 to 10 on a substrate. A liquid crystal display device comprising the liquid crystal photoalignment film according to claim 11.