Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display assembly

Abstract

The present application relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display device, and particularly relates to a liquid crystal alignment agent which is less likely to generate a residual image and has a low flicker, a liquid crystal alignment film formed from the liquid crystal alignment agent, and a liquid crystal display device having the liquid crystal alignment film. The liquid crystal alignment agent comprises: a polymer (A) comprising a first polymer (A1) and a second polymer (A2), the first polymer (A1) being obtained by reacting a first mixture, the first mixture comprising a tetracarboxylic dianhydride component (a1) and a diamine component (b1); and a solvent (B).

Description

Technical Field

[0001] This invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display component, particularly to a liquid crystal alignment agent that is not prone to image retention and has low flicker, a liquid crystal alignment film formed from the aforementioned liquid crystal alignment agent, and a liquid crystal display component having the aforementioned liquid crystal alignment film. Background Technology

[0002] Liquid crystal display components in LCD TVs, LCD monitors, etc., typically have a liquid crystal alignment film inside the component to control the alignment of the liquid crystals. Currently, the most common industrial method for forming liquid crystal alignment films is to form a film on an electrode substrate using polyamic acid and / or imidized polyimide, followed by a rubbing treatment (i.e., rubbing the film surface in a unidirectional direction with a cloth such as cotton, nylon, or polyester) to obtain the liquid crystal alignment film.

[0003] In the alignment process of liquid crystal alignment films, the easiest method to produce industrially is to perform a friction treatment on the film surface. However, with the increasing demands for high efficiency, high precision, and large size of liquid crystal display components, various problems such as damage to the liquid crystal alignment film surface, dust, the effects of mechanical and electrostatic forces, and non-uniformity on the alignment surface have become more pronounced during the friction treatment process.

[0004] As an alternative to friction treatment, photoalignment methods are currently known, which utilize ultraviolet irradiation by polarized light to impart alignment energy to liquid crystals. The liquid crystal alignment treatment in these photoalignment methods can include substances that utilize photoisomerization, photocrosslinking, or photodecomposition reactions in their reaction mechanisms. Furthermore, Japanese Patent Application Publication No. 9-297313 proposes a photoalignment method using a polyimide film with an alicyclic structure such as cyclobutane in its main chain. When polyimide is used as the alignment film for photoalignment, its heat resistance is higher than other types of alignment films, making its application highly anticipated.

[0005] Photoalignment is a method that does not require rubbing alignment. In industry, it not only has the advantage of simple process, but also, in liquid crystal display components driven by In-Plane-Switching (IPS) and Fringe Field Switching (FFS) technologies, compared with liquid crystal alignment films obtained by rubbing, it is expected to improve the contrast and viewing angle characteristics of the liquid crystal display components. Therefore, photoalignment is a promising and highly regarded liquid crystal alignment method.

[0006] However, when liquid crystal alignment films prepared by photoalignment are applied to liquid crystal display components, they still suffer from problems such as image retention and high flicker. Therefore, in order to meet the requirements of the current field of photoaligned IPS liquid crystal displays, providing a liquid crystal alignment agent for liquid crystal display components that is less prone to image retention and has low flicker has become the goal of researchers in this field. Summary of the Invention

[0007] This invention provides a liquid crystal alignment agent, comprising:

[0008] Polymer (A), comprising a first polymer (A1) and a second polymer (A2), the first polymer (A1) being prepared by reacting a first mixture comprising a tetracarboxylic dianhydride component (a1) and a diamine component (b1); and

[0009] Solvent (B);

[0010] The diamine component (b1) comprises at least one diamine compound (b1-1) as shown in formula (I):

[0011]

[0012] In equation (I), X represents -O-, -S-, and -NR. a -;

[0013] R a Represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms;

[0014] A represents a divalent organic group consisting of a benzene ring or an aromatic fused ring having 6 to 18 carbon atoms, wherein one or more hydrogen atoms of the benzene ring or the aromatic fused ring may be substituted by a monovalent organic group.

[0015] Y represents a single bond, an alkyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms with carbonyl substitution, or an alkenyl group having 2 to 5 carbon atoms;

[0016] R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and

[0017] b represents 0 or 1.

[0018] The present invention also provides a liquid crystal alignment film formed from the aforementioned liquid crystal alignment agent.

[0019] The present invention also provides a liquid crystal display component comprising the aforementioned liquid crystal alignment film. Attached Figure Description

[0020] Figure 1 This is a side view of a liquid crystal display assembly according to an embodiment of the present invention.

[0021] Symbol explanation:

[0022] 100: Liquid Crystal Display Components

[0023] 110: Unit 1

[0024] 112: First substrate

[0025] 114: First electrode

[0026] 116: The first liquid crystal alignment film

[0027] 120: Unit Two

[0028] 122: Second substrate

[0029] 126: Second liquid crystal alignment film

[0030] 130: Liquid Crystal Unit Detailed Implementation

[0031] This invention provides a liquid crystal alignment agent, comprising:

[0032] Polymer (A), comprising a first polymer (A1) and a second polymer (A2), the first polymer (A1) being prepared by reacting a first mixture comprising a tetracarboxylic dianhydride component (a1) and a diamine component (b1); and

[0033] Solvent (B);

[0034] The diamine component (b1) comprises at least one diamine compound (b1-1) as shown in formula (I):

[0035]

[0036] In equation (I), X represents -O-, -S-, and -NR. a -;

[0037] R a Represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms;

[0038] A represents a divalent organic group consisting of a benzene ring or an aromatic fused ring having 6 to 18 carbon atoms, wherein one or more hydrogen atoms of the benzene ring or the aromatic fused ring may be substituted by a monovalent organic group.

[0039] Y represents a single bond, an alkyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms with carbonyl substitution, or an alkenyl group having 2 to 5 carbon atoms;

[0040] R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and

[0041] b represents 0 or 1.

[0042] First polymer (A1)

[0043] The first polymer (A1) of the present invention is obtained by reacting a first mixture. Specifically, the first polymer (A1) may be selected from polyamic acid polymers, polyimide polymers, polyimide-based block copolymers, or any combination thereof. The polyimide-based block copolymer is selected from polyamic acid block copolymers, polyimide block copolymers, polyamic acid-polyimide block copolymers, or any combination thereof.

[0044] The first mixture comprises a tetracarboxylic dianhydride component (a1) and a diamine component (b1), wherein a preferred example of the tetracarboxylic dianhydride component (a1) is: (1) an aliphatic tetracarboxylic dianhydride compound; (2) an alicyclic tetracarboxylic dianhydride compound; (3) an aromatic tetracarboxylic dianhydride compound; or (4) a tetracarboxylic dianhydride compound having the formula (a1-1) to (a1-6), etc.

[0045] The (1) aliphatic tetracarboxylic dianhydride compounds of the present invention include, but are not limited to, aliphatic tetracarboxylic dianhydride compounds such as ethane tetracarboxylic dianhydride or butane tetracarboxylic dianhydride.

[0046] The (2) alicyclic tetracarboxylic dianhydride compounds of the present invention include, but are not limited to, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, Alicyclic tetracarboxylic anhydride compounds such as 2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, cis-3,7-dibutylcycloheptyl-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, or bicyclo[2.2.2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride.

[0047] Specific examples of the aromatic tetracarboxylic acid dianhydride compounds of the present invention (3) may include, but are not limited to, 3,4-dicarboxy-1,2,3,4-tetrahydronaphthalene-1-succinic acid dianhydride, benzyl tetracarboxylic acid dianhydride, 2,2',3,3'-benzophenone tetracarboxylic acid dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, 3,3',4,4'-biphenyl sulfone tetracarboxylic acid dianhydride, 1,4,5,8-naphthalene tetracarboxylic acid dianhydride, 2,3,6,7-naphthalene tetracarboxylic acid dianhydride, 3,3'-4,4'-diphenylethane tetracarboxylic acid dianhydride, 3,3',4,4'-dimethyldiphenylsilane tetracarboxylic acid dianhydride, 3,3',4,4'-tetraphenylsilane tetracarboxylic acid dianhydride, 1,2,3,4-furan tetracarboxylic acid dianhydride, and 2,3,3',4'-diphenyl Ether tetracarboxylic acid dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic acid dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 2,3,3',4'-diphenyl sulfide tetracarboxylic acid dianhydride, 3,3',4,4'-diphenyl sulfide tetracarboxylic acid dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfone dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidene phthalic acid dianhydride, 2,2',3,3'-diphenyltetracarboxylic acid dianhydride, 2,3,3',4'-diphenyltetracarboxylic acid dianhydride, 3,3',4,4'-diphenyltetracarboxylic acid dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-extrin-phenyl-bis(triphenylphthalic acid) Dihydride, m-extrin-phenyl-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride, ethylene glycol-bis(dehydrated trimellitate), propylene glycol-bis(dehydrated trimellitate), 1,4-butanediol-bis(dehydrated trimellitate), 1,6-hexanediol-bis(dehydrated trimellitate), 1,8-octanediol-bis(dehydrated trimellitate), 2,2-bis(4-hydroxyphenyl)propane-bis(dehydrated trimellitate), 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-disideloxy-3-furanyl)-naphtho[1,2-c]-furan -1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-methyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-ethyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7-methyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7-ethyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,3-dione[2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-ethyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5,8-dimethyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 5-(2,5-dioxytetrahydrofuranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, etc.

[0048] According to the invention, (4) comprises tetracarboxylic acid dianhydride compounds as shown in formulas (a1-1) to (a1-6), which are described in detail below.

[0049]

[0050]

[0051] In formulas (a1-5), A1 represents a divalent group containing an aromatic ring; r represents an integer from 1 to 2; A2 and A3 may be the same or different, and may represent a hydrogen atom or an alkyl group, respectively. Preferably, the tetracarboxylic dianhydride compound shown in formula (a1-5) may be selected from the compounds shown in formulas (a1-5-1) to (a1-5-3).

[0052]

[0053] In formula (a1-6), A4 represents a divalent group containing an aromatic ring; A5 and A6 may be the same or different, and respectively represent a hydrogen atom or an alkyl group. Preferably, the tetracarboxylic dianhydride compound shown in formula (a1-6) may be selected from the compound shown in formula (a1-6-1).

[0054]

[0055] In the tetracarboxylic dianhydride component (a1), the aforementioned tetracarboxylic dianhydride compound can be used alone or in combination.

[0056] Based on the use of 100 moles of diamine component (b1), the use of tetracarboxylic acid dianhydride component (a1) can be from 20 moles to 200 moles; preferably from 30 moles to 120 moles.

[0057] The diamine component (b1) of the first mixture comprises at least one diamine compound (b1-1) as shown in formula (I):

[0058]

[0059] In equation (I), X represents -O-, -S-, and -NR. a -;

[0060] R a Represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms;

[0061] A represents a divalent organic group consisting of a benzene ring or an aromatic fused ring having 6 to 18 carbon atoms, wherein one or more hydrogen atoms of the benzene ring or the aromatic fused ring may be substituted by a monovalent organic group.

[0062] Y represents a single bond, an alkyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms with carbonyl substitution, or an alkenyl group having 2 to 5 carbon atoms;

[0063] R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and

[0064] b represents 0 or 1.

[0065] In one embodiment, when b represents 1 in formula (I), the two A's in formula (I) may represent the same or different organic groups.

[0066] In one embodiment, instances of A in equation (I) may include, but are not limited to, the structures shown in equations (I-1) to (I-10):

[0067]

[0068]

[0069] In one embodiment, an example of the diamine compound (b1-1) represented by formula (I) may include, but is not limited to, compounds represented by formulas (I-11) to (I-24):

[0070]

[0071]

[0072]

[0073] In equations (I-11) to (I-24), m and n each independently represent integers from 0 to 4.

[0074] Based on the total amount of diamine component (b1) used being 100 moles, the amount of the diamine compound (b1-1) shown in formula (I) used may be from 5 moles to 70 moles; preferably from 5 moles to 65 moles; more preferably from 5 moles to 60 moles.

[0075] If the diamine component (b1) does not contain a diamine compound (b1-1), the resulting liquid crystal alignment agent will have problems such as easy image retention and high flicker.

[0076] The diamine component (b1) of the present invention may further comprise other diamine compounds (b1-2).

[0077] Other diamine compounds (b1-2) may include, but are not limited to, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 4,4'-diaminoheptane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-dimethylhexane, 1,7-diamino-2,5-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9-diamino-5-methylnonane, 2,11-diaminododecane, 1, 12-Diaminooctadecane, 1,2-bis(3-aminopropoxy)ethane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexylamine, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadiene diamine, tricyclo(6.2.1.02,7)-undecene dimethyl diamine, 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminobenzoylaniline, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 5-amine 1-(4'-aminophenyl)-1,3,3-trimethylhydroindene, 6-amino-1-(4'-aminophenyl)-1,3,3-trimethylhydroindene, hexahydro-4,7-methyl-bridged indene dimethylenediamine, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]sulfone, 1,4-bis(4-aminophenoxy)cyclohexane, 1,5-bis(4-aminophenoxymethylene)gold Anthracene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)-10-hydroanthracene, 9,10-bis(4-aminophenyl)anthracene, 2,7-diaminophen, 9,9-bis(4-aminophenyl)phen, 4,4'-methylene-bis(2-chloroaniline), 4,4'-(p-epylphenylisopropylidene)bisaniline, 4,4'-(m-epylphenylisopropylidene)bisaniline, 2,2'-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane, 4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl, 5-[4-(4-n-pentylcyclohexyl)cyclohexyl]phenylmethylene-1,3-diaminobenzene, 1,1-bis[4-(4-aminophenoxy)phenyl]-4-(4-ethylphenyl)cyclohexane phenyl)cyclohexane, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, bis(4-aminophenoxy)methane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,3-bis(3-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, or other diamine compounds as shown in formulas (b-1) to (b-29).

[0078] Equation (b-1) is shown below:

[0079]

[0080] In equation (b-1), Z1 represents Z2 represents a monovalent group containing a steroidal group, trifluoromethyl group, fluorine group, alkyl group with 2 to 30 carbon atoms, or a nitrogen-containing cyclic structure derived from pyridine, pyrimidine, triazine, piperidine, and piperazine.

[0081] The other diamine compounds shown in formula (b-1) above are preferably 2,4-diaminophenyl ethyl formate, 3,5-diaminophenyl ethylformate, 2,4-diaminophenyl propyl formate, 3,5-diaminophenyl propyl formate, 1-dodecoxy-2,4-diaminobenzene, 1-hexadecoxy-2,4-diaminobenzene, 1-octadecoxy-2,4-diaminobenzene, or other diamine compounds shown in formulas (b-1-1) to (b-1-6).

[0082]

[0083]

[0084] Equation (b-2) is shown below:

[0085]

[0086] In equation (b-2), Z3 represents Z4 and Z5 represent aliphatic rings, aromatic rings, or heterocyclic groups, and Z6 represents an alkyl group having 3 to 18 carbon atoms, an alkoxy group having 3 to 18 carbon atoms, a fluoroalkyl group having 1 to 5 carbon atoms, a fluoroalkoxy group having 1 to 5 carbon atoms, a cyano group, or a halogen atom.

[0087] Other diamine compounds shown in formula (b-2) above are preferably diamine compounds shown in formulas (b-2-1) to (b-2-13) below:

[0088]

[0089]

[0090]

[0091] In equations (b-2-10) to (b-2-13), s can represent an integer from 3 to 12.

[0092] Equation (b-3) is shown below:

[0093]

[0094] In formula (b-3), Z7 represents a hydrogen atom, an acyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen. P1 represents an integer from 1 to 3. When P1 is greater than 1, multiple Z7s can be the same or different.

[0095] The diamine compound represented by formula (b-3) above is preferably selected from: (1) p-diaminebenzene, m-diaminebenzene, o-diaminebenzene, or 2,5-diaminetoluene, etc., where P1 is 1; (2) 4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, etc., where P1 is 2. Biphenyl, 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl or 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, etc.; (3) 1,4-bis(4'-aminophenyl)benzene with P1 of 3, preferably selected from p-diaminobenzene, 2,5-diaminotoluene, 4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl or 1,4-bis(4'-aminophenyl)benzene.

[0096] Equation (b-4) is shown below:

[0097]

[0098] In formula (b-4) above, P2 represents an integer from 1 to 5. The structure shown in formula (b-4) is preferably selected from 4,4'-diaminodiphenyl sulfide.

[0099] Equation (b-5) is shown below:

[0100]

[0101] In equation (b-5), Z8 and Z 10 They can be the same or different, and each represents a divalent organic group. Z9 represents a divalent group derived from nitrogen-containing cyclic structures such as pyridine, pyrimidine, triazine, piperidine, and piperazine.

[0102] Equation (b-6) is shown below:

[0103]

[0104] In equation (b-6), Z 11 Z 12 Z 13and Z 14 They can be the same or different, and can represent hydrocarbon groups with 1 to 12 carbon atoms. P3 represents an integer from 1 to 3, and P4 represents an integer from 1 to 20.

[0105] Equation (b-7) is shown below:

[0106]

[0107] In equation (b-7), Z 15 Represents -O- or cyclohexyl, Z 16 Represents -CH2-, Z 17 Represents phenyl or cyclohexyl, and Z 18 It represents a hydrogen atom or a heptyl group.

[0108] The diamine compound shown in formula (b-7) is preferably selected from the diamine compounds shown in formulas (b-7-1) and (b-7-2) below.

[0109]

[0110]

[0111] Other diamine compounds represented by formulas (b-8) to (b-29) are shown below:

[0112]

[0113]

[0114]

[0115]

[0116] In equations (b-16) to (b-19), Z 19 Preferably, it is an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. In formulas (b-20) to (b-24), Z 20 Preferably, it is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0117] Other diamine compounds (b1-2) preferably include, but are not limited to, 1,2-diaminoethane, 4,4'-diaminodicyclohexylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 5-[4-(4-n-pentylcyclohexyl)cyclohexyl]phenylmethylene-1,3-diaminobenzene, 1,3-bis(3-aminophenoxy)benzene, 1,1-bis[4-(4-aminophenoxy)phenyl]-4-(4-ethyl Compounds represented by (b-2,4-diaminophenyl)cyclohexane, ethyl 2,4-diaminophenylformate, p-diaminebenzene, m-diaminebenzene, o-diaminebenzene, 1,2-bis(4-aminophenoxy)ethane, 1,5-bis(4-aminophenoxy)pentane, and compounds represented by formula (b-1-1), (b-1-2), (b-1-5), (b-2-1), (b-2-11), (b-7-1), (b-25), or (b-28).

[0118] The other diamine compounds (b1-2) mentioned above can be used alone or in combination.

[0119] The total amount of diamine component (b1) used is 100 moles, and the amount of other diamine compounds (b1-2) used is 30 to 95 moles; preferably 35 to 95 moles; more preferably 40 to 95 moles.

[0120] Preparation method of the first polymer (A1)

[0121] The preparation of the polyamic acid polymer of the present invention can be carried out by a general method. Preferably, the preparation method of the aforementioned polyamic acid polymer includes the following steps: dissolving a first mixture containing a tetracarboxylic acid dianhydride component (a1) and a diamine component (b1) in a solvent, carrying out a polycondensation reaction at a temperature of 0°C to 100°C for 1 hour to 24 hours, and then performing vacuum distillation on the above reaction solution using an evaporator to obtain the polyamic acid polymer, or pouring the above reaction solution into a large amount of undesirable solvent to obtain a precipitate, and then drying the precipitate by vacuum drying to obtain the polyamic acid polymer.

[0122] The solvent used in the polycondensation reaction may be the same as or different from the solvent in the liquid crystal alignment agent described below, and there are no particular limitations on the solvent used in the polycondensation reaction, as long as it can dissolve the reactants and products. Preferably, the solvent includes, but is not limited to, (1) aprotic polar solvents, such as: N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea or hexamethyltriamine phosphate and other aprotic polar solvents; (2) phenolic solvents, such as: m-cresol, xylenol, phenol or halogenated phenols and other phenolic solvents. Based on the amount of the mixture used being 100 parts by weight, the amount of solvent used in the polycondensation reaction is preferably from 200 parts by weight to 2000 parts by weight, more preferably from 300 parts by weight to 1800 parts by weight.

[0123] In particular, in the polycondensation reaction, an appropriate amount of unsuitable solvent can be used as a solvent, wherein the unsuitable solvent will not cause the polyamic acid polymer to precipitate. Unsuitable solvents can be used alone or in combination, and include, but are not limited to, (1) alcohols, such as methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol or triethylene glycol; (2) ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; (3) esters, such as methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate or ethylene glycol ethyl ether acetate; (4) ethers. For example: ethers such as diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether or diethylene glycol dimethyl ether; (5) halogenated hydrocarbons, such as: dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene or o-dichlorobenzene; (6) hydrocarbons, such as: tetrahydrofuran, hexane, heptane, octane, benzene, toluene or xylene or any combination of the above solvents. Based on the use of 100 parts by weight of the diamine component (b1), the use of the undesirable solvent is preferably 0 to 60 parts by weight, more preferably 0 to 50 parts by weight.

[0124] The preparation of the polyimide polymer of the present invention can be carried out by a general method. Preferably, the preparation method of the polyimide polymer first involves dissolving a first mixture in a solution, wherein the first mixture contains a tetracarboxylic acid dianhydride component (a1) and a diamine component (b1), and then carrying out a polymerization reaction to form a polyamic acid polymer. Next, in the presence of a dehydrating agent and a catalyst, the mixture is further heated, and a dehydration dead-cycle reaction is carried out, causing the amic acid functional groups in the polyamic acid polymer to be converted into imide functional groups (i.e., imidization) through the dehydration dead-cycle reaction, thereby obtaining the polyimide polymer.

[0125] The solvent used in the dehydration dead-cycle reaction can be the same as the solvent in the liquid crystal alignment agent described below, and therefore will not be described again. Based on the amount of polyamic acid polymer used being 100 parts by weight, the amount of solvent used in the dehydration dead-cycle reaction is preferably 200 to 2000 parts by weight, more preferably 300 to 1800 parts by weight.

[0126] To obtain a better degree of imidization in the polyamic acid polymer, the operating temperature of the dehydration dead-cycle reaction is preferably between 40°C and 200°C, more preferably between 40°C and 150°C. If the operating temperature of the dehydration dead-cycle reaction is below 40°C, the imidization reaction is incomplete, thus reducing the degree of imidization of the polyamic acid polymer. However, if the operating temperature of the dehydration dead-cycle reaction is above 200°C, the weight average molecular weight of the resulting polyimide polymer is lower.

[0127] The dehydrating agent used in the dehydration dead-cycle reaction can be selected from acid anhydride compounds, specifically, acetic anhydride, propionic anhydride, or trifluoroacetic anhydride. Based on 1 mole of polyamic acid polymer, the amount of dehydrating agent used is 0.01 mole to 20 moles. The catalyst used in the dehydration dead-cycle reaction can be selected from: (1) pyridine compounds, such as pyridine, trimethylpyridine, or dimethylpyridine; (2) tertiary amine compounds, such as triethylamine. Based on 1 mole of dehydrating agent, the amount of catalyst used is 0.5 moles to 10 moles.

[0128] Preferred examples of the polyimide-based block copolymers of the present invention are polyamic acid block copolymers, polyimide block copolymers, polyamic acid-polyimide block copolymers, or any combination thereof.

[0129] The preparation of the polyimide-based block copolymer of the present invention can be carried out by a general method. Preferably, the preparation method of the polyimide-based block copolymer is to first dissolve the starting material in a solvent and carry out a polycondensation reaction, wherein the starting material comprises at least one polyamic acid polymer and / or at least one polyimide polymer mentioned above, and may further comprise a tetracarboxylic dianhydride component (a1) and a diamine component (b1).

[0130] The tetracarboxylic dianhydride component (a1) and diamine component (b1) in the aforementioned starting material are the same as those used in the preparation of polyamic acid polymers, and the solvent used in the polycondensation reaction can be the same as the solvent in the liquid crystal alignment agent described below, which will not be repeated here.

[0131] Based on the aforementioned starting material being used in an amount of 100 parts by weight, the amount of solvent used in the polycondensation reaction is preferably from 200 parts by weight to 2000 parts by weight, more preferably from 300 parts by weight to 1800 parts by weight. The operating temperature of the polycondensation reaction is preferably from 0°C to 200°C, and more preferably from 0°C to 100°C.

[0132] Preferably, the starting material comprises, but is not limited to: (1) two polyamic acid polymers with different end groups and different structures; (2) two polyimide polymers with different end groups and different structures; (3) a polyamic acid polymer and a polyimide polymer with different end groups and different structures; (4) a polyamic acid polymer, a tetracarboxylic dianhydride compound and a diamine compound, wherein at least one of the tetracarboxylic dianhydride compound and the diamine compound has a different structure from the tetracarboxylic dianhydride component (a1) and the diamine component (b1) used to form the polyamic acid polymer; (5) a polyimide polymer, a tetracarboxylic dianhydride compound and a diamine compound, wherein at least one of the tetracarboxylic dianhydride compound and the diamine compound has a different structure from the tetracarboxylic dianhydride component (a1) and the diamine component (b1) used to form the polyimide polymer; (6) a polyamic acid polymer and a polyimide polymer. (7) Two polyamic acid polymers, tetracarboxylic acid dianhydride compounds and diamine compounds, wherein at least one of the tetracarboxylic acid dianhydride compounds and diamines has a structure different from that of the tetracarboxylic acid dianhydride component (a1) and the diamine component (b1) used to form polyamic acid polymers or polyimide polymers; (8) Two polyimide polymers, tetracarboxylic acid dianhydride compounds and diamine compounds with different structures; (9) Two polyamic acid polymers and diamine compounds with anhydride end groups and different structures; (10) Two polyamic acid polymers and tetracarboxylic acid dianhydride compounds with amine end groups and different structures; (11) Two polyimide polymers and diamine compounds with anhydride end groups and different structures; (12) Two polyimide polymers and tetracarboxylic acid dianhydride compounds with amine end groups and different structures.

[0133] Preferably, without affecting the effectiveness of the present invention, the aforementioned polyamic acid polymer, the aforementioned polyimide polymer, and the aforementioned polyimide-based block copolymer can be end-modified polymers after prior molecular weight adjustment. By using end-modified polymers, the coating performance of the liquid crystal alignment agent can be improved. The aforementioned end-modified polymers can be prepared by adding a monofunctional compound during the polycondensation reaction of the polyamic acid polymer. The monofunctional compound includes, but is not limited to: (1) monocarboxylic anhydrides, such as maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride or n-hexadecyl succinic anhydride, etc.; (2) monoamine compounds, such as aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecaneamine, n-dodecaneamine, n-tridecaneamine, n-tetradecaneamine, n-pentadecananeamine, n-hexadecaneamine, n-heptadecaneamine, n-octadecaneamine or n-eicosaneamine, etc.; (3) monoisocyanate compounds, such as phenyl isocyanate or naphthyl isocyanate, etc.

[0134] The first polymer (A1) of the present invention has a weight-average molecular weight of 10,000 to 100,000, more preferably 12,000 to 90,000, and even more preferably 12,000 to 75,000, as determined by gel permeation chromatography.

[0135] Second polymer (A2)

[0136] The second polymer (A2) of the present invention is obtained by reacting a second mixture. Specifically, the second polymer (A2) may be selected from polyamic acid polymers, polyimide polymers, polyimide-based block copolymers, or any combination thereof. The polyimide-based block copolymer is selected from polyamic acid block copolymers, polyimide block copolymers, polyamic acid-polyimide block copolymers, or any combination thereof.

[0137] The second mixture comprises a tetracarboxylic dianhydride component (a2) and a diamine component (b2), wherein the tetracarboxylic dianhydride component (a2) comprises at least one tetracarboxylic dianhydride compound (a2-1) represented by formula (III):

[0138]

[0139] In formula (II), R1, R2, R3 and R4 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group containing a fluorine atom and having 1 to 6 carbon atoms, or a phenyl group. R1, R2, R3 and R4 may be the same or different, and at least one of R1, R2, R3 and R4 is not a hydrogen atom.

[0140] When R1, R2, R3, and R4 have a steric barrier structure, the liquid crystal alignment of the liquid crystal alignment agent will be poor. Therefore, R1, R2, R3, and R4 are preferably hydrogen atoms, methyl groups, or ethyl groups, with methyl groups being more preferred.

[0141] Specific examples of the tetracarboxylic acid dianhydride compound (a2-1) with the structure shown in formula (II) can be the compounds shown in formulas (II-1) to (II-8). Formula (II-1) is preferred for liquid crystal alignment.

[0142]

[0143]

[0144] The aforementioned tetracarboxylic acid dianhydride compound (a2-1) can be used alone or in combination.

[0145] Based on the total amount of tetracarboxylic dianhydride component (a2) being used in 100 moles, the amount of tetracarboxylic dianhydride compound (a2-1) being used can be from 30 moles to 100 moles; preferably from 40 moles to 100 moles; more preferably from 50 moles to 100 moles.

[0146] If the tetracarboxylic dianhydride component (a2) contains a tetracarboxylic dianhydride compound (a2-1), the resulting liquid crystal display component will have lower flicker.

[0147] The tetracarboxylic dianhydride component (a2) may also include other tetracarboxylic dianhydride compounds (a2-2), the types of which may be the same as those listed in the tetracarboxylic dianhydride component (a1) of the aforementioned first polymer (A1), and therefore will not be described further here.

[0148] The total amount of tetracarboxylic dianhydride component (a2) used is 100 moles, and the amount of other tetracarboxylic dianhydride compounds (a2-2) used is 0 to 70 moles; preferably 0 to 60 moles; more preferably 0 to 50 moles.

[0149] The diamine component (b2) comprises at least one diamine compound (b2-1) selected from diamine compounds having the structure shown in formula [A-1], diamine compounds having the structure shown in formula [A-2], and diamine compounds having the structure shown in formula [A-3]:

[0150]

[0151]

[0152] In formulas [A-1] to [A-3], R5 and R6 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a protecting group, and at least one of them is a protecting group; R7, R8, and R9 each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent hydrocarbon group having 1 to 20 carbon atoms with a substituent; D represents a protecting group.

[0153] From the viewpoint of the storage stability of the liquid crystal alignment agent, the protecting group is preferably one that does not detach at room temperature, and more preferably one that detaches at 80°C or above, and more preferably at 100°C or above. The protecting group is preferably a group represented by the following formula (1) or a 9-fluorenylmethoxycarbonyl group.

[0154]

[0155] In formula (1), E represents a single bond or a divalent group containing a hydrocarbon group having 1 to 4 carbon atoms, preferably a divalent group containing an alkylene group, and from the viewpoint of the removal temperature, preferably a tert-butoxycarbonyl (Boc).

[0156] As a preferred example of a diamine compound having the structure shown in formula [A-1] above, diamine compounds as shown in formula [A-1-1] can be cited.

[0157]

[0158] In equation [A-1-1], R5 and R6 are the same as in equation [A-1], and also include their respective preferred examples. Each of the two cs independently represents an integer from 0 to 3, preferably 0 or 1, and more preferably 1.

[0159] In addition, in formula [A-1-1], the bonding position of the amino group (-NH2) in each benzene ring relative to the alkylene group can be any one of the ortho, meta, or para positions, preferably ortho or para, and more preferably para.

[0160] As preferred examples of diamine compounds represented by formula [A-1-1], the following compounds can be listed.

[0161]

[0162]

[0163] In formula [A-2], R7 and R8 each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent hydrocarbon group having 1 to 20 carbon atoms with substituents, preferably a hydrogen atom, an alkyl or phenyl group having 1 to 6 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0164] D represents a protecting group, including its preferred examples, as defined in formula [A-2] above, and more preferably a tert-butoxycarbonyl group.

[0165] The diamine compound having the structure shown in formula [A-2] is preferably the diamine compound shown in formula [A-2-1].

[0166]

[0167] Preferably, the compound is a diamine compound represented by formula [A-2-2].

[0168]

[0169] A 1 and A 5 Each independently represents a single bond or an alkylene group having 1 to 5 carbon atoms, preferably a single bond or a methylene group. A 2 and A 4 Represents an alkylene group having 1 to 5 carbon atoms, preferably methylene or ethylene.

[0170] A 3 Represents an alkylene or cycloalkylene group having 1 to 6 carbon atoms, preferably a methylene or ethylene group.

[0171] B 1 and B 2 Each can independently represent a single bond, -O-, -NH-, -NMe-, -C(=O)-, -C(=O)O-, -C(=O)NH-, -C(=O)NMe-, -OC(=O)-, -NHC(=O)- or -N(Me)C(=O)-, with single bonds or -O- being preferred.

[0172] D1 represents tert-butoxycarbonyl or 9-fluorenylmethoxycarbonyl, with tert-butoxycarbonyl being preferred from the viewpoint of deprotection temperature.

[0173] a is 0 or 1.

[0174] As specific examples of the diamine represented by formula [A-2-2], formulas (2-1) to (2-21) can be listed below.

[0175]

[0176]

[0177]

[0178] In formulas (2-1) to (2-21), Me represents methyl and D2 represents tert-butoxycarbonyl.

[0179] Among them, equations (2-1) to (2-4) are preferred, and equation (2-1) is even more preferred.

[0180] The diamine compound having the structure shown in formula [A-3] is preferably the one shown in formula [A-3-1] or formula [A-3-2].

[0181]

[0182] The preferred forms are shown in equations [A-3-3] and [A-3-4].

[0183]

[0184] In equations [A-3-1] and [A-3-3], A 1 A 5 A 2 B 1 and B 2 With A in equation [A-2-1] 1 A 5 A 2 B 1 and B 2 The same applies, including their respective preferred examples. R9 each independently represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent hydrocarbon group having 1 to 20 carbon atoms with substituents. From the viewpoint of liquid crystal orientation, R9 is preferably a hydrogen atom, a methyl or ethyl group, and more preferably a hydrogen atom.

[0185] A 6 The single bond represents an alkylene group having 1 to 6 carbon atoms, preferably a single bond, methylene, ethylene, or propylene, and more preferably a single bond or methylene.

[0186] D1 is either tert-butoxycarbonyl or 9-fluorenylmethoxycarbonyl, and from the viewpoint of the deprotection temperature, tert-butoxycarbonyl is preferred.

[0187] In equations [A-3-2] and [A-3-4], A 6 R9 and D1 are related to A in equations [A-3-1] and [A-3-3]. 6 R9 and D1 are the same, and also include their respective best examples.

[0188] As specific examples, equations (3-1) to (3-5) can be listed.

[0189]

[0190] In formulas (3-1) to (3-5), D2 is tert-butoxycarbonyl.

[0191] Among them, equations (3-1) to (3-4) are more preferred, and equation (3-1) is even more preferred.

[0192] The aforementioned diamine compound (b2-1) can be used alone or in combination.

[0193] Based on the total amount of diamine component (b2) used being 100 moles, the amount of diamine compound (b2-1) used can be from 1 mole to 50 moles; preferably from 1 mole to 45 moles; more preferably from 5 moles to 40 moles.

[0194] When the diamine component (b) contains a diamine compound (b2-1), the resulting liquid crystal alignment agent is less prone to image retention.

[0195] The diamine component (b2) may further include other diamine compounds (b2-2), the types of which may be the same as those listed in the diamine component (b1-2) of the aforementioned first polymer (A1), and therefore will not be repeated here.

[0196] The total amount of diamine component (b2) used is 100 moles, and the amount of other diamine compounds (b2-2) used is 50 to 99 moles; preferably 55 to 99 moles; more preferably 60 to 95 moles.

[0197] Preparation method of the second polymer (A2)

[0198] The preparation method of the second polymer (A2) of the present invention is the same as that of the first polymer (A1) described above. The difference is that the second polymer (A2) is prepared by reacting the aforementioned tetracarboxylic acid dianhydride component (a2) and diamine component (b2). Therefore, the preparation method of the second polymer (A2) will not be described again here.

[0199] The second polymer (A2) of the present invention has a weight-average molecular weight of 10,000 to 100,000, more preferably 12,000 to 90,000, and even more preferably 12,000 to 75,000, as determined by gel permeation chromatography.

[0200] The total amount of polymer (A) used is 100 parts by weight, the amount of the first polymer (A1) used is 15 parts by weight to 95 parts by weight, preferably 20 parts by weight to 90 parts by weight, more preferably 25 parts by weight to 90 parts by weight; and the amount of the second polymer (A2) used is 5 parts by weight to 85 parts by weight, preferably 10 parts by weight to 80 parts by weight, more preferably 10 parts by weight to 75 parts by weight.

[0201] When the amounts of the first polymer (A1) and the second polymer (A2) used are within the aforementioned range, the resulting liquid crystal alignment agent exhibits a lower scintillation rate.

[0202] Solvent (B)

[0203] The solvent used in the liquid crystal alignment agent of the present invention is not particularly limited, as long as it can dissolve the polymer (A) and any other component without reacting with them. Preferably, it is the same solvent used in the synthesis of polyamic acid mentioned above. At the same time, the lean solvent used in the synthesis of polyamic acid mentioned above can also be used.

[0204] Specific examples of solvent (B) include, but are not limited to, N-methyl-2-pyrrolidone (NMP), γ-butyrolactone, γ-butyrolactam, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, or N,N-dimethylformamide or N,N-dimethylacetamide.

[0205] Solvent (B) can be used alone or in combination.

[0206] The amount of polymer (A) used is 100 parts by weight, and the amount of solvent (B) used is 800 to 4000 parts by weight, preferably 900 to 3500 parts by weight, and even more preferably 1000 to 3000 parts by weight.

[0207] Additive (C)

[0208] Without affecting the effectiveness of the present invention, the liquid crystal alignment agent of the present invention may selectively include an additive (C), and the additive (C) may be an epoxy compound or a silane compound having functional groups, etc. The function of the additive (C) is to improve the adhesion between the aforementioned liquid crystal alignment film and the substrate surface. The additive (C) may be used alone or in combination.

[0209] The aforementioned epoxy compounds may include, but are not limited to, ethylene glycol 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, glycerol diglycidyl ether, 2,2-dibromonepentyl glycol diglycidyl ether, 1,3,5,6-tetracyclooxypropyl-2,4-hexanediol, N,N N',N'-Tetracyclooxypropyl-m-xylenediamine, 1,3-bis(N,N-dicyclooxypropylaminomethyl)cyclohexane, N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane, N,N-epoxypropyl-p-epoxypropoxyaniline, 3-(N-allyl-N-epoxypropyl)aminopropyltrimethoxysilane, 3-(N,N-dicyclooxypropyl)aminopropyltrimethoxysilane, etc.

[0210] Based on the amount of polymer (A) used being 100 parts by weight, the amount of epoxy compound used is generally less than 40 parts by weight, and preferably 0.1 parts by weight to 30 parts by weight.

[0211] The aforementioned silane compounds with functional groups may include, but are not limited to, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, and N-triethoxysilyl Propyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triacryldecane, 10-triethoxysilyl-1,4,7-triacryldecane, 9-trimethoxysilyl-3,6-diacrylnonyl acetate, 9-triethoxysilyl-3,6-diacrylnonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(ethylene oxide)-3-aminopropyltrimethoxysilane, N-bis(ethylene oxide)-3-aminopropyltriethoxysilane, etc.

[0212] Based on the amount of polymer (A) used being 100 parts by weight, the amount of silane compound used is generally less than 10 parts by weight, and preferably 0.5 parts by weight to 10 parts by weight.

[0213] Based on the amount of polymer (A) used being 100 parts by weight, the amount of additive (C) used can be from 0.5 parts by weight to 50 parts by weight, and more preferably from 1 part by weight to 45 parts by weight.

[0214] Preparation method of liquid crystal alignment agent

[0215] The preparation method of the liquid crystal alignment agent of the present invention is not particularly limited, and a general mixing method can be used. For example, a first polymer (A1) and a second polymer (A2) are first mixed to form polymer (A), and then polymer (A) is added to solvent (B) and additive (C) at a temperature of 0°C to 200°C, and stirred continuously with a stirring device until dissolved. Preferably, polymer (A) and additive (C) are added to solvent (B) at a temperature of 20°C to 60°C.

[0216] Method for forming liquid crystal alignment film

[0217] The present invention also provides a liquid crystal alignment film formed from the aforementioned liquid crystal alignment agent. In one embodiment, the liquid crystal alignment agent may be coated on a substrate and subjected to pre-baking, post-baking, and photoalignment treatment to form the liquid crystal alignment film.

[0218] The substrate coated with the liquid crystal alignment agent of the present invention is selected from transparent materials. These transparent materials include, but are not limited to, alkali-free glass, soda-lime glass, hard glass (Pellegrino glass), quartz glass, polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, etc., used in liquid crystal display devices. Preferably, a substrate on which the ITO electrode for liquid crystal driving is already formed is used to simplify the process. Furthermore, for reflective liquid crystal displays with only a single-sided substrate, the aforementioned substrate can be made of an opaque material such as a silicon wafer. In this case, the electrode can be formed using a light-reflecting material such as aluminum. The coating method for the liquid crystal alignment agent of the present invention can be, for example, spin coating, printing, inkjet printing, etc.

[0219] The liquid crystal alignment agent of this invention can be applied at any temperature and for any time for drying and baking. Generally, to fully remove the contained organic solvents, drying at 50°C to 120°C for 1 to 10 minutes is required. Afterward, baking at 150°C to 300°C for 5 to 120 minutes is performed. There is no particular limitation on the thickness of the coating after baking, but an excessively thin coating will degrade the reliability of the liquid crystal display; therefore, a coating thickness of 5 nm to 300 nm is preferable, with 10 nm to 200 nm being even more ideal.

[0220] Although the liquid crystal alignment agent of the present invention can be subjected to well-known triboelectric alignment treatment, it is even more effective when using photoalignment treatment.

[0221] Specific examples of the photoalignment treatment method include: irradiating the surface of the aforementioned coating film with radiation polarized in a specific direction, and then heating it at a temperature of 150°C to 250°C, as appropriate, to impart liquid crystal alignment energy to the coating film. Ultraviolet or visible light with wavelengths of 100nm to 800nm ​​can be used as the radiation, with ultraviolet light with wavelengths of 100nm to 400nm being preferred, and ultraviolet light with wavelengths of 200nm to 400nm being even more preferred. Furthermore, to improve liquid crystal alignment, the coating substrate can be irradiated with radiation while being heated at 150°C to 250°C. The preferred irradiation dose of the aforementioned radiation is 1 mJ / cm². 2 Up to 10,000 mJ / cm 2 And with 100mJ / cm 2 Up to 5,000 mJ / cm 2 For even better results, the liquid crystal alignment film prepared in the above manner can stably align liquid crystal molecules in a certain direction.

[0222] The liquid crystal alignment agent of the present invention is subjected to pre-baking treatment, post-baking treatment and photoalignment treatment to form a liquid crystal alignment film, wherein the pretilt angle of the liquid crystal alignment film is 0° to 3°.

[0223] Manufacturing method of liquid crystal display components

[0224] The present invention also provides a liquid crystal display component comprising the aforementioned liquid crystal alignment film.

[0225] The manufacturing process of liquid crystal display components is well known to those skilled in the art, therefore, it will only be briefly described below.

[0226] See Figure 1 A preferred embodiment of the liquid crystal display component 100 of the present invention includes a first unit 110, a second unit 120 and a liquid crystal unit 130, wherein the second unit 120 is spaced apart from the first unit 110 and the liquid crystal unit 130 is disposed between the first unit 110 and the second unit 120.

[0227] The first unit 110 includes a first substrate 112, a first electrode 114 and a first liquid crystal alignment film 116, wherein the first electrode 114 is formed on the surface of the first substrate 112 in a pectin patterned manner, and the first liquid crystal alignment film 116 is formed on the surface of the electrode 114.

[0228] The second unit 120 includes a second substrate 122 and a second liquid crystal alignment film 126, wherein the second liquid crystal alignment film 126 is formed on the surface of the second substrate 122.

[0229] The first substrate 112 and the second substrate 122 are selected from transparent materials, including but not limited to alkali-free glass, soda-lime glass, hard glass (Pyles glass), quartz glass, polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, etc., used in liquid crystal display devices. The electrode 114 is made of transparent electrodes selected from tin oxide (SnO2), indium oxide-tin oxide (In2O3-SnO2), etc.; or metal electrodes such as chromium.

[0230] The first liquid crystal alignment film 116 and the second liquid crystal alignment film 126 are the liquid crystal alignment films mentioned above. Their function is to enable the liquid crystal cell 130 to form a pretilt angle, and the liquid crystal cell 130 can be driven by the parallel electric field generated by the electrode 114.

[0231] The liquid crystal used in the liquid crystal unit 130 can be used alone or in combination. The liquid crystals include, but are not limited to, diaminobenzene-based liquid crystals, pyridazine-based liquid crystals, Schiff base-based liquid crystals, azo-based liquid crystals, biphenyl-based liquid crystals, phenylcyclohexane-based liquid crystals, biphenyl-based liquid crystals, ester-based liquid crystals, terphenyl-based liquid crystals, biphenylcyclohexane-based liquid crystals, pyrimidine-based liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, and cubane-based liquid crystals. Furthermore, depending on requirements, additional substances such as cholesterol chloride, cholesterol nonanoate, and cholesterol carbonate can be added. Cholesterol-type liquid crystals such as carbonate, or chiral agents with trade names such as "C-15" or "CB-15" (manufactured by Merck), or ferroelectric liquid crystals such as p-decoxybenzyl methylene-p-amino-2-methylbutyl cinnamate.

[0232] The liquid crystal alignment agent of this invention provides liquid crystal display components suitable for various types of nematic liquid crystals, such as TN, STN, TFT, VA, and IPS liquid crystal display components. Furthermore, depending on the selected liquid crystal, it can also be used for liquid crystal display components with strong or negative strong conductivity. Among the aforementioned liquid crystal display components, it is particularly suitable for IPS-type liquid crystal display components.

[0233] The present invention will now be described in detail with reference to the following examples, but it is not intended to imply that the present invention is limited to the content disclosed in these examples.

[0234] Synthetic polymer (A1)

[0235] Synthesis example A1-1

[0236] A nitrogen inlet, stirrer, condenser, and thermometer were installed on a 500 mL four-necked conical flask, and nitrogen gas was introduced. Then, 0.0025 mol of compound (I-11) (b1-1-1), 0.04 mol of p-diaminebenzene (b1-2-1), 0.0075 mol of 2,2'-dimethyl-4,4'-diaminobiphenyl (b1-2-2), and 80 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) were added, and the mixture was stirred at room temperature. Dissolve; then add 0.05 mol of 2,3,5-tricarboxycyclopentylacetic dianhydride (a1-1) and 20 g of NMP, and react at room temperature for 2 hours; after the reaction is complete, pour the reaction solution into 1500 mL of water to precipitate the polymer, filter the obtained polymer, and repeat the washing and filtration steps with methanol three times; then, place the product in a vacuum oven and dry it at 60 °C to obtain polymer (A1-1), the formulation of which is shown in Table 1.

[0237] Synthetic Examples A1-2 to A1-10 and Comparative Synthetic Examples A1'-1 to A1'-2

[0238] Synthetic Examples A1-2 to A1-10 and Comparative Examples A1'-1 to A1'-2 used the same preparation method as the polymer (A1-1) of Synthetic Example A1-1. The difference was that the types and amounts of raw materials in the polymer were changed in Synthetic Examples A1-2 to A1-10 and Comparative Examples A1'-1 to A1'-2. Their formulations are shown in Table 1 and will not be described again here.

[0239]

[0240] In Table 1:

[0241]

[0242] b1-1-1 Compound shown in formula (I-11)

[0243] Compound b1-2-1, shown in formula (I-12), is p-diaminebenzene.

[0244] Compound b1-1-3 (I-13) is 2,2'-dimethyl-4,4'-diaminobiphenyl.

[0245] Compound b1-2-3, 4,4'-methylenebis(cyclohexylamine), as shown in formula (I-24), is also known as b1-1-4.

[0246] Compound b1-2-4, 1,4-diaminocyclohexane, as shown in formula (I-15) b1-1-5

[0247] Compound shown in formula (I-22) b1-1-6

[0248] Compound shown in formula (I-23) b1-1-7

[0249] Compound shown in formula (I-20) b1-1-8

[0250] Synthetic polymer (A2)

[0251] Synthesis Examples A2-1 to A2-12

[0252] Synthetic Examples A2-1 to A2-12 use the same preparation method as the polymer (A1-1) of Synthetic Example A1-1. The difference is that the types and amounts of raw materials in the polymer are changed in Synthetic Examples A2-1 to A2-12. Their formulations are shown in Table 2 and will not be described again here.

[0253]

[0254] In Table 2:

[0255] Compound a2-1-1, shown in formula (II-1), is 2,3,5-tricarboxycyclopentylacetic dianhydride.

[0256] Compound a2-1-2, shown in formula (II-2), is a2-2-2 1,2,3,4-cyclobutanetetracarboxylic dianhydride.

[0257] Compound a2-2-3, represented by formula (II-3), is abenzyl tetracarboxylic acid dianhydride.

[0258] Compound a2-1-4 shown in formula (II-5)

[0259] Compounds shown in formula (II-8) of a2-1-5

[0260]

[0261] Compound b2-1-5 (Formula (2-7)) and compound b2-1-9 (Formula (3-1))

[0262] Compound b2-1-6 (as shown in formula (2-2)) and compound b2-1-10 (as shown in formula (3-3))

[0263] b2-2-1 p-Diaminebenzene b2-2-4 1,4-Diaminocyclohexane

[0264] b2-2-2 2,2'-Dimethyl-4,4'-Diaminobiphenyl b2-2-5 1,2-Bis(4-aminophenoxy)ethane

[0265] b2-2-3 4,4'-Methylenebis(cyclohexylamine) b2-2-6 1,5-bis(4-aminophenoxy)pentane

[0266] Example 1

[0267] Preparation of liquid crystal alignment agent

[0268] Weigh 15 parts by weight of polymer (A1-1) of synthesis example A1-1, 85 parts by weight of polymer (A2-1) of synthesis example A2-1, and 800 parts by weight of NMP, and stir and mix them at room temperature to obtain the liquid crystal alignment agent of Example 1.

[0269] Preparation of liquid crystal alignment film and liquid crystal display component

[0270] The liquid crystal alignment agent prepared above is spin-coated onto a glass substrate, wherein a pixel electrode is formed on the glass substrate. The pixel electrode is an IPS driving electrode having a pair of ITO electrodes (electrode width: 10 μm, electrode spacing: 10 μm, electrode height: 50 nm). The pair of ITO electrodes each has a serrated shape, and the serrated portions of each other are arranged in a separated and interlocking manner. Then, the glass substrate coated with the liquid crystal alignment agent is dried on a heating plate at 80°C for 5 minutes, and then baked in a hot air circulating oven at 250°C for 60 minutes to form a coating with a film thickness of 100 nm.

[0271] A substrate with a liquid crystal alignment film is prepared by irradiating the coated surface with ultraviolet light at a wavelength of 254 nm through a polarizing plate. Next, a coating is formed on a counter substrate, which is a glass substrate without electrodes but with columnar spacers of 4 μm in height, and an alignment treatment is applied.

[0272] The two substrates are a set. A sealant is printed on one of them, and the other is bonded together with the liquid crystal alignment film facing each other and the alignment direction is 0°. The sealant is then hardened to obtain an empty cell. This empty cell is injected with liquid crystal MLC-2041 (manufactured by Merck) using a depressurized injection method, and the injection port is sealed, which is the liquid crystal display component of Example 1.

[0273] The liquid crystal display component of Example 1 was evaluated using the evaluation method described below, and the results are shown in Table 3-1.

[0274] Examples 2 to 15 and Comparative Examples 1 to 4

[0275] Examples 2 to 15 and Comparative Examples 1 to 4 used the same preparation method as the liquid crystal alignment agent in Example 1. The difference was that the types and amounts of raw materials in the liquid crystal alignment agent were changed in Examples 2 to 15 and Comparative Examples 1 to 4. The formulations and evaluation results are shown in Tables 3-1, 3-2 and 4, respectively, and will not be described again here.

[0276] Table 3-1:

[0277]

[0278] Table 3-2:

[0279]

[0280] Table 4:

[0281]

[0282] Tables 3-1, 3-2, and 4:

[0283]

[0284] flicker test

[0285] The liquid crystal display components of Examples 1 to 15 and Comparative Examples 1 to 4 were placed between two polarizing plates arranged in a perpendicular manner with their polarizing axes intersecting. The LED backlight was lit without any applied voltage. The arrangement angle of the liquid crystal display components was adjusted to minimize the brightness of the transmitted light. Then, an AC voltage with a frequency of 30 Hz was applied to the liquid crystal display components, and the VT curve (voltage-transmittance curve) was measured at the same time. The AC voltage with a relative transmittance of 23% was calculated and used as the driving voltage.

[0286] The flicker measurement method involves turning off the lit LED backlight at a temperature of 23°C for the liquid crystal display module, placing it in a darkened state for 72 hours, and then turning it back on. Simultaneously with the backlight activation, an AC voltage of 30Hz with a relative transmittance of 23% is applied to drive the liquid crystal display module for 60 minutes, and the flicker amplitude is tracked. The flicker amplitude is measured using a data acquisition / recording switching device 34970A (manufactured by Agilent Technologies) connected to a photodiode and an IV converter, reading the brightness value passing through two polarizing plates and the liquid crystal display module between them. The flicker is calculated according to the following formula (V). A lower flicker indicates a better quality liquid crystal display module made with that liquid crystal alignment agent.

[0287]

[0288] In formula (V), z is the brightness value read when the device 34970A described above is driven by an AC voltage of 30Hz at a frequency of 23% relative transmittance.

[0289] ◎: Flicker rate <3%

[0290] ○: 4% > flickering intensity ≥ 3%

[0291] △: 5% > flicker ≥ 4%

[0292] X: Flicker level ≥ 5%.

[0293] Afterimage Test

[0294] After driving the liquid crystal display components of Examples 1 to 15 and Comparative Examples 1 to 4 with an AC voltage of 10V for 30 hours, the minimum relative transmittance (%) was measured using a device in which a polarizer and an analyzer are arranged between the light source and the light quantity detector.

[0295]

[0296] In the above formula, B0 is blank and represents the amount of light transmitted under crossed nicols; B 100 β is the light transmittance under parallel nicols, which is the amount of light transmitted when the liquid crystal cell is sandwiched between the polarizer and the analyzer under cross-nicols.

[0297] The black level in a dark state is represented by the minimum relative transmittance of the liquid crystal display module. The lower the black level, the better the contrast, that is, the better the image retention.

[0298] ◎: Minimum relative transmittance ≤ 0.5%

[0299] ○: 0.5% < minimum relative transmittance ≤ 1.0%

[0300] △: 1.0% < minimum relative transmittance ≤ 1.5%

[0301] X: Minimum relative transmittance > 1.5%.

[0302] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the invention. Modifications and variations made to the above embodiments by those skilled in the art do not depart from the spirit of the invention. The scope of the invention should be defined by the claims.

Claims

1. A liquid crystal alignment agent for photoalignment, comprising: Polymer (A), comprising a first polymer (A1) and a second polymer (A2), the first polymer (A1) being prepared by reacting a first mixture comprising a tetracarboxylic dianhydride component (a1) and a diamine component (b1); and Solvent (B); in, The diamine component (b1) comprises at least one diamine compound (b1-1) as shown in formula (I): Equation (I) In equation (I), X represents -O-, -S-, and -NR. a -; R a Represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; A represents ; Y represents a single bond, an alkylene group having 1 to 5 carbon atoms, an alkylene group having 1 to 5 carbon atoms with carbonyl substitution, or an alkenyl group having 2 to 5 carbon atoms; R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and b represents 0; The second polymer (A2) is prepared by reacting a second mixture comprising a tetracarboxylic dianhydride component (a2) and a diamine component (b2), wherein the tetracarboxylic dianhydride component (a2) comprises at least one tetracarboxylic dianhydride compound (a2-1) selected from the group consisting of formulas (II-1) to (II-8): Equation (II-1) Equation (II-2) Equation (II-3) Equation (II-4) Equation (II-5) Equation (II-6) Equation (II-7) Equation (II-8) Wherein, based on the total amount of the diamine component (b1) used being 100 moles, the amount of the diamine compound (b1-1) shown in formula (I) used being 5 to 70 moles; based on the total amount of the tetracarboxylic dianhydride component (a2) used being 100 moles, the amount of the tetracarboxylic dianhydride compound (a2-1) shown in formula (II) used being 30 to 100 moles; based on the total amount of the polymer (A) used being 100 parts by weight, the amount of the first polymer (A1) used being 15 to 95 parts by weight, and the amount of the second polymer (A2) used being 5 to 85 parts by weight.

2. The liquid crystal alignment agent for photoalignment as claimed in claim 1, wherein, The second polymer (A2) is prepared by reacting a second mixture comprising a tetracarboxylic dianhydride component (a2) and a diamine component (b2), wherein the diamine component (b2) comprises at least one diamine compound (b2-1) selected from diamine compounds having the structure shown in formula [A-1], diamine compounds having the structure shown in formula [A-2], and diamine compounds having the structure shown in formula [A-3]. Formula [A-1] Formula [A-2] Formula [A-3] In formulas [A-1] to [A-3], R5 and R6 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a protecting group, and at least one of R5 and R6 is a protecting group; R7 and R8 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group; R9 represents a hydrogen atom, a methyl group, or an ethyl group; and D represents a protecting group.

3. The liquid crystal alignment agent for photoalignment as claimed in claim 2, wherein, Based on a total usage of 100 moles of the diamine component (b2), the usage of the diamine compound (b2-1) shown in formulas [A-1] to [A-3] is from 1 mole to 50 moles.

4. The liquid crystal alignment agent for photoalignment as claimed in claim 1, wherein, Based on the amount of polymer (A) used being 100 parts by weight, the amount of solvent (B) used being from 800 parts by weight to 3000 parts by weight.

5. A liquid crystal alignment film formed from a liquid crystal alignment agent for photoalignment as claimed in any one of claims 1-4.

6. The liquid crystal alignment film as claimed in claim 5, wherein, The liquid crystal alignment agent for photoalignment is pre-baked, post-baked, and photoaligned to form the liquid crystal alignment film.

7. A liquid crystal display component comprising a liquid crystal alignment film as claimed in claim 5 or 6.

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