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

Abstract

The invention provides a liquid crystal alignment agent capable of reducing contrast variation in pixels, a liquid crystal alignment film formed by using the liquid crystal alignment agent, and a liquid crystal display component comprising the liquid crystal alignment film. The liquid crystal alignment agent comprises a polymer (A) with a specific structure.

Description

Technical Field

[0001] The present invention relates to a liquid crystal alignment agent, and in particular to a liquid crystal alignment agent capable of reducing contrast variation within a pixel, a liquid crystal alignment film formed using the liquid crystal alignment agent, and a liquid crystal display component comprising the liquid crystal alignment film. Background Art

[0002] Known liquid crystal display units are widely used as display components of personal computers, smart phones, cellular phones, or television receivers. Liquid crystal display units may include, for example, a liquid crystal layer sandwiched between a component substrate and a color filter substrate, a pixel electrode and a common electrode for applying an electric field to the liquid crystal layer, an alignment film for controlling the alignment of liquid crystal molecules in the liquid crystal layer, and a thin film transistor (TFT) for switching the electronic signal supplied to the pixel electrode. As for the driving method of liquid crystal molecules, there are known longitudinal electric field methods such as TN (Twisted Nematic) method and VA (Vertical Alignment) method, and transverse electric field methods such as IPS (In-Plane Switching) method and FFS (Fringe Field Switching) method.

[0003] At present, the most popular liquid crystal alignment film in the industry is a film surface composed of polyamic acid and / or polyimide obtained by imidization, which has been formed on an electrode substrate, and is made by rubbing it in one direction with a cloth such as cotton, nylon or polyester. Friction treatment is a simple and highly productive industrial method. However, with the high performance, high precision and large-scale liquid crystal display components, the surface of the alignment film is scarred by dust, mechanical force and static electricity generated by the friction treatment, which leads to various problems such as unevenness within the alignment treatment surface. As an alignment treatment method that replaces the friction treatment, a photoalignment method is known that imparts liquid crystal alignment ability by irradiating polarized radiation. Regarding the photoalignment method, Japanese Patent Gazette No. 9-297313 has disclosed those that use photoisomerization reactions, those that use photocrosslinking reactions or those that use photodecomposition reactions. However, when a liquid crystal display device using a known liquid crystal alignment film prepared by a photo-alignment method implements a black display, the contrast variation within the pixel is relatively large, which in turn causes the brightness within the screen to vary, and there is a concern that the display quality will be reduced. The purpose of the present invention is to provide a liquid crystal alignment film that can effectively reduce the contrast variation within the pixel, a liquid crystal alignment agent for obtaining the liquid crystal alignment film, and a liquid crystal display device using the liquid crystal alignment film.

[0004] The inventors of the present invention have made great efforts to achieve the above-mentioned objectives and have found that a liquid crystal alignment film formed by a liquid crystal alignment agent containing a polymer with a specific structure is very effective in achieving the above-mentioned objectives, thereby completing the present invention. Summary of the invention

[0005] In view of this, one aspect of the present invention is to provide a liquid crystal alignment agent, which comprises a polymer (A). The liquid crystal alignment film formed by the liquid crystal alignment agent can effectively reduce the contrast variation within a pixel of a liquid crystal display device.

[0006] Another aspect of the present invention is to provide a liquid crystal alignment film, which is formed by using the above-mentioned liquid crystal alignment agent.

[0007] Another aspect of the present invention is to provide a liquid crystal display unit, which includes the aforementioned liquid crystal alignment film and has a lower intra-pixel contrast variation.

[0008] According to the above aspect of the present invention, a liquid crystal alignment agent is provided. The liquid crystal alignment agent of the present invention contains a polymer (A). A preferred embodiment of the liquid crystal alignment agent of the present invention can be listed as a liquid crystal alignment agent containing a polymer (A) and an organic solvent. In addition, the liquid crystal alignment agent of the present invention may also contain a polymer other than the polymer (A) (such as the polymer (B) described later).

[0009] Polymer (A)

[0010] The polymer (A) of the present invention can be selected from at least one polymer selected from the group consisting of a polyimide precursor obtained by reacting a tetracarboxylic acid derivative component (a1) and a diamine component (a2), and an imidized polymer of a polyimide precursor. For example, the polymer (A) may include a polyimide precursor having an imide precursor structure such as polyamic acid and polyamic acid ester. The diamine component (a2) may include a diamine compound (a2-1) as shown in the following formula (A21).

[0011]

[0012] In formula (A21), Y 11 represents a hydrocarbon group having 1 to 10 carbon atoms; and n and m each independently represent 0 to 3.

[0013] Tetracarboxylic acid derivative component (a1)

[0014] The tetracarboxylic acid derivative component (a1) that reacts with the diamine component (a2) may be a tetracarboxylic acid dianhydride compound, or a tetracarboxylic acid dianhydride derivative such as a tetracarboxylic acid dihalide, a tetracarboxylic acid dialkyl ester, or a tetracarboxylic acid dialkyl ester dihalide. The tetracarboxylic acid derivative component (a1) may be a single tetracarboxylic acid dianhydride compound or a derivative thereof, or may be a mixture of a plurality of them.

[0015] The tetracarboxylic acid derivative component (a1) of the present invention may include an alicyclic tetracarboxylic dianhydride compound (a1-1) represented by formula (A11) and other tetracarboxylic dianhydride compounds (a1-2).

[0016] Alicyclic tetracarboxylic dianhydride compound (a1-1)

[0017] The tetracarboxylic acid derivative component (a1) used for the reaction to obtain the polymer (A) may include an alicyclic tetracarboxylic dianhydride compound (a1-1) or a derivative thereof as shown in the following formula (A11). The alicyclic tetracarboxylic dianhydride compound (a1-1) or a derivative thereof shown in formula (A11) may be composed of a single tetracarboxylic dianhydride compound or a derivative thereof, or may be composed of a plurality of tetracarboxylic dianhydride compounds or derivatives thereof. In the present invention, the alicyclic tetracarboxylic dianhydride compound (a1-1) shown in formula (A11) may be, for example, an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an alicyclic structure. However, none of the four carboxyl groups are bonded to an aromatic ring. Alternatively, it is not necessary to be composed only of an alicyclic structure, and a portion thereof may also have a chain hydrocarbon structure or an aromatic ring structure. The aromatic tetracarboxylic dianhydride may be, for example, an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an aromatic ring. However, it is not necessary to consist of only an aromatic ring structure, and a part of it may have a chain hydrocarbon structure or an alicyclic structure. Non-cyclic aliphatic tetracarboxylic dianhydride may be, for example, an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. However, it is not necessary to consist of only a chain hydrocarbon structure, and a part of it may have an alicyclic structure or an aromatic ring structure.

[0018]

[0019] In formula (A11), X1 can be selected from at least one of the group consisting of structures shown in the following formulae (A11-1) to (A11-7), and "*" represents a bonding position.

[0020]

[0021] In formula (A11-1), X 11 , X 12 , X 13 With X 14 Each independently represents 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 having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group. 15 With X 16 Each independently represents a hydrogen atom or a methyl group.

[0022] In some embodiments, X1 may represent the structures shown in the following formulae (A11-1-1) to (A11-1-6).

[0023]

[0024] Preferably, X1 represents a structure shown in formula (A11-1-1). When X1 represents a structure shown in formula (A11-1-1), that is, the tetracarboxylic acid derivative component (a1) comprises an alicyclic tetracarboxylic dianhydride compound or a derivative thereof as shown in the following formula, a liquid crystal display unit containing a liquid crystal alignment film formed therefrom has a lower intra-pixel contrast variation.

[0025]

[0026] Based on the total usage of the tetracarboxylic acid derivative component (a1) as 100 mol, the usage of the alicyclic tetracarboxylic dianhydride compound (a1-1) represented by formula (A11) is 30 mol to 100 mol, preferably 40 mol to 100 mol, and more preferably 50 mol to 100 mol.

[0027] Other tetracarboxylic dianhydride compounds (a1-2)

[0028] Other tetracarboxylic dianhydride compounds (a1-2) may include tetracarboxylic dianhydride compounds represented by the following formula (A12) and derivatives thereof.

[0029]

[0030] In formula (A12), X1′ may represent a structure as shown in the following formula (A12-1) to formula (A12-32), wherein “*” represents a bonding position.

[0031]

[0032]

[0033]

[0034]

[0035] In formula (A12-5) and formula (A12-6), X 11 ' and X 12 'respectively independently represent a single bond, -O-, -CO-, -COO-, a phenylene group, a sulfonyl group or an amide group, and in formula (A12-6), multiple X 12 ' may be the same or different from each other. a1 in formula (A12-5) represents an integer of 0 or 1. a1 in formula (A12-6) represents an integer of 0 or 1. In formula (A12-14), X 13'respectively 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 having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group, and multiple X 13 ' may be the same or different from each other. Based on the viewpoint of liquid crystal alignment, X 13 ' preferably represents a hydrogen atom, a halogen atom, a methyl group or an ethyl group, and more preferably represents a hydrogen atom or a methyl group.

[0036] In some specific examples, the aforementioned formula (A12-5) and formula (A12-6) may include but are not limited to the structures shown below.

[0037]

[0038]

[0039] The above-mentioned other tetracarboxylic dianhydride compounds (a1-2) may be used alone or in combination of plural kinds.

[0040] Based on the total usage of the tetracarboxylic acid derivative component (a1) being 100 mol, the usage of the other tetracarboxylic dianhydride compound (a1-2) may be 0 mol to 70 mol, preferably 0 mol to 60 mol, and more preferably 0 mol to 50 mol.

[0041] Diamine component (a2)

[0042] The diamine component (a2) of the present invention may include a diamine compound (a2-1), a diamine compound (a2-2), a diamine compound (a2-3), a diamine compound (a2-4) and other diamine compounds (a2-5).

[0043] Diamine compound (a2-1)

[0044] The diamine component (a2) of the present invention comprises a diamine compound (a2-1) represented by the following formula (A21).

[0045]

[0046] In formula (A21), Y 11 represents a hydrocarbon group having 1 to 10 carbon atoms; and n and m each independently represent 0 to 3.

[0047] From the viewpoint of synthesis and orientation, the diamine compound (a2-1) represented by formula (A21) may preferably include a diamine compound represented by the following formula (A21'). Further, the hydrogen atoms on the benzene ring bonded to the amine groups at both ends in formula (A21) may be substituted, such as 1 to 2 hydrogen atoms of the benzene ring are substituted with halogen, alkyl having 1 to 3 carbon atoms, alkoxy having 1 to 3 carbon atoms, fluoroalkyl having 1 to 3 carbon atoms, or fluoroalkoxy having 1 to 3 carbon atoms.

[0048]

[0049] In formula (A21'), Y 11 The definitions of , m and n are as described above.

[0050] The aforementioned Y 11 The represented hydrocarbon group is at least one selected from the group consisting of an aliphatic chain hydrocarbon group, an aliphatic cyclic hydrocarbon group and an aromatic hydrocarbon group.

[0051] The aforementioned aliphatic chain hydrocarbon group refers to a straight-chain or branched hydrocarbon group that does not contain a cyclic structure in the main chain and is only composed of a chain structure, which may be saturated or unsaturated. The aforementioned aliphatic cyclic hydrocarbon group refers to a hydrocarbon group that contains an alicyclic structure and does not contain an aromatic ring structure. However, the aliphatic cyclic hydrocarbon group does not have to be composed only of a hydrocarbon group with an alicyclic structure, and some of them may have a chain structure.

[0052] In the specific example of the aliphatic chain hydrocarbon group having a carbon number of 1 to 10, these hydrocarbon groups may include saturated and unsaturated aliphatic chain hydrocarbon groups. The saturated aliphatic chain hydrocarbon group may be a saturated straight chain or branched chain hydrocarbon group. The saturated straight chain hydrocarbon group may include, for example, but not limited to, a methylene group, an ethylene group, a propanediyl group, a butanediyl group, a pentanediyl group, a hexanediyl group, a heptanediyl group, an octanediyl group, a nonanediyl group, or a decanediyl group. The saturated branched chain hydrocarbon group may include, for example, but not limited to, a second butanediyl group, a third butanediyl group, an isopentanediyl group, a third pentanediyl group, an isooctanediyl group, a 2-ethylhexanediyl group, a third octanediyl group, an isononanediyl group, or an isodecanediyl group.

[0053] The unsaturated aliphatic chain hydrocarbon group may include an unsaturated chain hydrocarbon group having an unsaturated bond (such as an olefinic bond and / or an acetylenic bond), and these groups may also be straight chain or branched. For example, the unsaturated aliphatic chain hydrocarbon group may include but is not limited to ethylenediyl, heptenediyl, 2-butenediyl, 3-methyl-4-ethyl-1-hexenediyl, propynyldiyl, 2-hexynyldiyl, 3-methyl-1-pentynyldiyl, 3-ethyl-1-heptynyldiyl or 3,5-dimethyl-4-hexene-1-heptynyldiyl. In addition, specific examples of alicyclic hydrocarbon groups having 3 to 10 carbon atoms may include but are not limited to cyclobutanediyl, cyclopentanediyl, cyclohexanediyl, cycloheptanediyl, and the hydrogen atoms on the aforementioned rings may be substituted.

[0054] The aromatic hydrocarbon group may include, but is not limited to, a benzene ring, a naphthalene ring, a tetralin ring, an azulene ring, an indene ring, a fluorene ring, an anthracene ring, a phenanthrene ring or a phenalene ring. 11 Preferably, it represents an aliphatic chain hydrocarbon group having 1 to 5 carbon atoms, and more preferably represents a saturated straight chain hydrocarbon group having 1 to 3 carbon atoms. 11 When Y represents an aliphatic chain hydrocarbon group with a carbon number of 1 to 5, the prepared liquid crystal alignment agent will make the formed liquid crystal display device have a lower intra-pixel contrast variation. 11 When the saturated straight-chain hydrocarbon group has a carbon number of 1 to 3, the intra-pixel contrast variation of the formed liquid crystal display device can be further reduced.

[0055] In some specific examples, the diamine compound (a2-1) represented by formula (A21) may include but is not limited to the diamine compounds represented by the following formulae (A21-1) to (A21-10).

[0056]

[0057]

[0058]

[0059] The aforementioned diamine compound (a2-1) may be used alone or in combination of two or more.

[0060] Based on 100 mol of the total usage of the diamine component (a2), the usage of the diamine compound (a2-1) may be 1 mol to 95 mol, preferably 5 mol to 90 mol, and more preferably 10 mol to 85 mol.

[0061] If the diamine component (a2) does not include the diamine compound (a2-1) represented by formula (A21), the obtained liquid crystal alignment agent will cause the formed liquid crystal display device to have too high intra-pixel contrast variation.

[0062] The main synthesis methods of the diamine compound (a2-1) are described in detail below. The methods described below are only for illustration, and the preparation of the diamine compound (a2-1) in this case is not limited thereto.

[0063] For example, the diamine compound represented by formula (A21-8) can be prepared by reducing a dinitro compound to convert the nitro group into an amine group according to the following reaction formula (S21-1).

[0064]

[0065] The reduction method of the dinitro compound is not particularly limited. For example, palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina or platinum sulfide carbon can be used as a catalyst, and the reduction can be carried out by hydrogen, hydrazine and hydrogen chloride in a solvent such as ethyl acetate, toluene, tetrahydrofuran, dioxane and / or alcohol. It can also be carried out under pressure using an autoclave as needed. On the other hand, when the substituent structure of the hydrogen atom of the benzene ring or saturated hydrocarbon group contains an unsaturated bond, when palladium-carbon or platinum sulfide carbon is used, the unsaturated bond of the substituent may be reduced to a saturated bond. Therefore, it is preferred to use a transition metal such as reduced iron, tin or tin chloride as a catalyst.

[0066] The aforementioned dinitro compound can be synthesized by reaction as shown in the following reaction formula (S21-2), which can be obtained by reacting a commercially available aliphatic or aromatic diol derivative with nitrobenzene substituted with a leaving group (X). The leaving group (X) can preferably be, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a toluene sulfonate (-OTs) or a mesylate (-OMs).

[0067]

[0068] The reaction shown in reaction formula (S21-2) can be carried out in the presence of a base. The base used is not particularly limited as long as it can be synthesized, and inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide and / or sodium hydride can be listed; and organic bases such as pyridine, dimethylaminopyridine, trimethylamine, triethylamine and / or tributylamine. Depending on the situation, when a palladium catalyst or a copper catalyst such as dibenzylideneacetone palladium or diphenylphosphinoferrocene palladium is used in combination, the yield can be increased. Based on the viewpoint of easy synthesis, it is preferably a method using pyridine, but methods other than this method can also synthesize dinitro compounds, so the synthesis method of dinitro compounds is not particularly limited.

[0069] Diamine compound (a2-2)

[0070] The diamine component (a2) of the present invention may include a diamine compound (a2-2) represented by the following formula (A22).

[0071] H2N-R1-R4-R2-R6-R5-R7-R3-NH2 (A22)

[0072] In formula (A22), R1, R2 and R3 independently represent a divalent organic group of a benzene ring or a pyridine ring; R4 represents an oxygen atom or a sulfur atom; R5 represents a divalent chain hydrocarbon group having 1 to 30 carbon atoms or an alicyclic hydrocarbon group having 3 to 30 carbon atoms; R6 and R7 independently represent a single bond, an oxygen atom, a sulfur atom or -NR8-, wherein at least one of R6 and R7 represents an oxygen atom, a sulfur atom or -NR8-, and R8 represents a hydrogen atom or a methyl group; when any one of R1, R2 and R3 is a pyridine ring, R6 and R7 do not represent a single bond. When the diamine component (a2) comprises the diamine compound (a2-2) shown in formula (A22), the obtained liquid crystal alignment agent will enable the formed liquid crystal display device to have a lower intra-pixel contrast variation.

[0073] Preferably, R5 represents a divalent chain hydrocarbon group with a carbon number of 1 to 30; more preferably, R5 represents a divalent chain hydrocarbon group with a carbon number of 1 to 11; and particularly preferably, R5 represents a straight chain alkylene group with a carbon number of 1 to 11. When R5 represents the aforementioned substituent, the obtained liquid crystal display device containing the liquid crystal alignment agent has a lower intra-pixel contrast variation.

[0074] The chain hydrocarbon group represented by the aforementioned R5 refers to a straight-chain or branched hydrocarbon group that does not contain a cyclic structure in the main chain and is only composed of a chain structure, which may be saturated or unsaturated. The alicyclic hydrocarbon group represented by the aforementioned R5 refers to a hydrocarbon group containing an alicyclic structure and does not contain a hydrocarbon group with an aromatic ring structure. However, it is not necessary to be composed only of hydrocarbon groups with an alicyclic structure, and some of them may have a chain structure. In the specific example of a chain hydrocarbon group with a carbon number of 1 to 30, these hydrocarbon groups may include saturated and unsaturated chain hydrocarbon groups. Saturated chain hydrocarbon groups may be saturated straight-chain or branched hydrocarbon groups. Saturated straight-chain hydrocarbon groups may be methylene, ethyl, propanediyl, butanediyl, pentanediyl, hexanediyl, heptanediyl, octanediyl, nonanediyl, decanediyl, dodecanediyl, tetradecanediyl, pentadecanediyl, hexadecanediyl and octadecanediyl. The saturated branched hydrocarbon group may be, for example, sec-butanediyl, t-butanediyl, isopentanediyl, t-pentanediyl, isooctanediyl, 2-ethylhexanediyl, t-octanediyl, isononanediyl and isodecanediyl.

[0075] The unsaturated chain hydrocarbon group may include an unsaturated chain hydrocarbon group having an unsaturated bond (such as an olefinic bond and / or an acetylenic bond), and these groups may also be straight chain or branched. For example: ethylenediyl, heptenediyl, 2-butenediyl, 3-methyl-4-ethyl-1-hexenediyl, propynyldiyl, 2-hexynyldiyl, 3-methyl-1-pentynyldiyl, 3-ethyl-1-heptynyldiyl and 3,5-dimethyl-4-hexene-1-heptynyldiyl. In addition, specific examples of alicyclic hydrocarbon groups having 3 to 30 carbon atoms may include cyclobutanediyl, cyclopentanediyl, cyclohexanediyl, cycloheptanediyl and groups in which hydrogen atoms on the rings are substituted.

[0076] In some specific examples, the diamine compound (a2-2) represented by formula (A22) may include but is not limited to the specific diamine compounds represented by the following formulas (A22-1) to (A22-38).

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] In formula (A22-1), formula (A22-3), formula (A22-5), formula (A22-6), formula (A22-8), formula (A22-14) and formula (A22-24) to formula (A22-34), Ra represents a hydrogen atom or a methyl group, but is not limited to these and may also represent other groups.

[0086] The aforementioned diamine compound (a2-2) may be used alone or in combination of two or more.

[0087] In the synthesis of a fully obtained polymer (A) (such as polyamic acid (PAA)), based on the usage of the diamine component (a2) being 100 mol, the usage of the diamine compound (a2-2) as shown in formula (A22) is 5 mol to 99 mol, preferably 7 mol to 95 mol, and more preferably 10 mol to 40 mol. The main synthesis method of the diamine compound (a2-2) is described in detail below. The method described below is only for illustration, and the preparation of the diamine compound (a2-2) in this case is not limited thereto.

[0088] For example, the diamine compound represented by formula (A22-7) can be prepared by reducing a dinitro compound to convert the nitro group into an amine group according to the following reaction formula (S22-1).

[0089]

[0090] The reduction method of the dinitro compound is not particularly limited. Examples include palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon, etc., as catalysts, in solvents such as ethyl acetate, toluene, tetrahydrofuran, dioxane and alcohols, and reduction by hydrogen, hydrazine and hydrogen chloride. It is also possible to use an autoclave under pressure as needed. On the other hand, when the substituent structure of the hydrogen atom of the substituted benzene ring or saturated hydrocarbon group contains an unsaturated bond, when palladium-carbon or platinum sulfide carbon is used, the unsaturated bond may be reduced to a saturated bond. Therefore, it is preferred to use a transition metal such as reduced iron, tin or tin chloride as a catalyst for the reduction condition.

[0091] The aforementioned dinitro compound can be synthesized by reaction as shown in the following reaction formula (S22-2), which can be obtained by reacting a commercially available diphenyl ether derivative, a phenoxypyridine derivative or a bipyridine ether derivative with nitrobenzene or nitropyridine substituted with a leaving group (X). The leaving group (X) can preferably be, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a toluene sulfonate (-OTs) or a mesylate (-OMs).

[0092]

[0093] The reaction shown in reaction formula (S21-2) can be carried out in the presence of a base. The base used is not particularly limited as long as it can be synthesized, and inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide and / or sodium hydride can be listed; and organic bases such as pyridine, dimethylaminopyridine, trimethylamine, triethylamine and / or tributylamine. Depending on the situation, when a palladium catalyst or a copper catalyst such as dibenzylideneacetone palladium or diphenylphosphinoferrocene palladium is used in combination, the yield can be increased. From the viewpoint of easy synthesis, it is preferably a method using potassium carbonate, but it can also be synthesized outside this method, so the synthesis method of the dinitro compound is not particularly limited.

[0094] Diamine compound (a2-3)

[0095] The diamine component (a2) of the present invention may include a diamine compound (a2-3), and the diamine compound (a2-3) may include a diamine compound represented by the following formula (A23-1) or formula (A23-2).

[0096]

[0097] In formula (A23-1), Y 31 represents a divalent organic group as shown in the following formula (A23-3). 32 Each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. 33Each independently represents a divalent organic group represented by the following formula (A23-3').

[0098]

[0099] In formula (A23-3), Ar each independently represents a divalent benzene ring, a biphenyl structure or a naphthalene ring, and the hydrogen atoms of the benzene ring, the biphenyl structure or the naphthalene ring may be substituted by a monovalent substituent or may not be substituted; Y 31 ' represents -(CH2) n -, n represents an integer from 2 to 18, and -(CH2) n At least one -CH2- in - may be substituted by -O-, -C(=O)- or -OC(=O)- or may be unsubstituted; p1 represents an integer of 0 or 1; "*" represents a bonding position.

[0100] In formula (A23-3'), Ar' independently represents a divalent benzene ring or a biphenyl structure, and the hydrogen atoms of the benzene ring or the biphenyl structure may be substituted by a monovalent substituent or may not be substituted; Y 33 ' represents -(CH2) n -, n represents an integer from 2 to 18, and -(CH2) n At least one -CH2- in - may be substituted by -O-, -C(=O)- or -OC(=O)- or may be unsubstituted; p2 represents an integer of 0 or 1; "*" represents a bonding position.

[0101] The monovalent substituent group of the aforementioned benzene ring, biphenyl structure, or naphthalene ring may be, for example, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, a fluoroalkenyl group having 2 to 10 carbon atoms, a fluoroalkoxy group having 1 to 10 carbon atoms, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms, a cyano group, or a nitro group. From the viewpoint of improving the alignment of the liquid crystal, the divalent organic group represented by formula (A23-3) may preferably include the groups represented by the following formulas (A23-3-1) to (A23-3-16), wherein "*" represents the bonding position.

[0102]

[0103]

[0104] In formula (A23-3-14), each of m independently represents an integer of 1 to 3.

[0105] From the viewpoint of improving the liquid crystal alignment, the divalent organic group represented by formula (A23-3′) may preferably include groups represented by formula (A23-3-7) to formula (A23-3-16).

[0106] When the diamine compound (a2-3) comprises a plurality of diamine compounds as shown in formula (A23-1), it is preferably Y in formula (A23-1): 31 The diamine compounds represented by formula (A23-3-1) to formula (A23-3-14) and Y in formula (A23-1) 31 It represents a combination of diamine compounds of formula (A23-3-15) to formula (A23-3-16).

[0107] In some specific examples, the diamine compound represented by the aforementioned formula (A23-2) may include but is not limited to the diamine compounds represented by the following formulas (A23-2-1) to (A23-2-5).

[0108]

[0109]

[0110] The aforementioned diamine compounds (a2-3) may be used alone or in combination of two or more.

[0111] Based on 100 mol of the total usage of the diamine component (a2), the usage of the diamine compound (a2-3) may be 5 mol to 99 mol, preferably 10 mol to 90 mol, and more preferably 15 mol to 87 mol.

[0112] Diamine compound (a2-4)

[0113] Based on the viewpoint of improving the voltage holding rate of the liquid crystal display component, the molecular structure of the polymer (A) may selectively have an -N(D)- group (wherein D represents a carbamate as a protecting group). The polymer (A) having an -N(D)- group may be obtained by using a monomer having an -N(D)- group as at least a part of the reaction raw material, or by using it as a capping agent as described later. In some specific examples, the monomer having an -N(D)- group may be, for example, a diamine compound (a2-4) having an -N(D)- group. For example, the carbamate as a protecting group may include but is not limited to tert-butyloxycarbonyl and 9-fluorenylmethoxycarbonyl.

[0114] Preferably, the diamine compound (a2-4) having an -N(D)- group includes a diamine compound having at least one aromatic group such as a benzene ring. More preferably, the diamine compound (a2-4) having an -N(D)- group includes a diamine compound having at least one aromatic group such as a benzene ring, and the residue other than the substituent (D) is a diamine compound having a carbon number of 6 to 30. In some specific examples, the diamine compound (a2-4) having an -N(D)- group may include but is not limited to the diamine compounds shown in the following formulas (A24-1) to (A24-10).

[0115]

[0116]

[0117] The aforementioned diamine compounds (a2-4) may be used alone or in combination of two or more.

[0118] Based on 100 mol of the total usage of the diamine component (a2), the usage of the diamine compound (a2-4) may be 5 mol to 99 mol, preferably 10 mol to 52 mol, and more preferably 15 mol to 37 mol.

[0119] Other diamine compounds (a2-5)

[0120] In addition to the aforementioned diamine compound (a2-1) as shown in formula (A21), the diamine compound (a2-2) as shown in formula (A22), the diamine compound (a2-3) and the diamine compound (a2-4), the diamine component (a2) used to obtain the polymer (A) may selectively include other diamine compounds (a2-5). For example, other diamine compounds (a2-5) may include but are not limited to: 4,4'-diaminoazobenzene or diamine compounds such as those shown in formulas (A25-1) to (A25-3) below, which have a photo-alignment group; 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol or 4,6-diaminoresorcinol; 2,4- Diamine compounds having a carboxyl group, such as diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid or diamine compounds represented by the following formula (A25-4) to (A25-7); 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ketone, 1,4-bis(4-aminobenzyl)benzene, 4,4'-diaminodiphenyl ether, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-dihydroindene-5-amine or 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine; diamine compounds having urea bonds such as diamine compounds represented by formula (A25-8) to (A25-10); diamine compounds having amide bonds such as diamine compounds represented by formula (A25-11) to (A25-13); diamine compounds having photopolymerizable groups at the ends such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallylaniline; diamines having siloxane bonds, such as 3-bis(3-aminopropyl)-tetramethyldisiloxane; diamine compounds having urea bonds such as diamine compounds represented by formula (A25-14) to (A25-15) A diamine compound with an oxazoline structure.

[0121]

[0122]

[0123] In formula (A25-4), Y 51 represents a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -CH2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)- or -N(CH3)CO-; m1 and m2 each independently represent an integer from 0 to 4, and (m1+m2) represents an integer from 1 to 4. In formula (A25-5), m3 and m4 each independently represent an integer from 1 to 5. In formula (A25-6), Y 52 represents a linear or branched alkyl group having 1 to 5 carbon atoms; m5 represents an integer from 1 to 5. In formula (A25-7), Y 53 and Y 54 Each independently represents a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -CH2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)- or -N(CH3)CO-; m6 represents an integer from 1 to 4.

[0124] The above-mentioned other diamine compounds (a2-5) may be used alone or in combination of plural types.

[0125] Based on 100 mol of the total usage of the diamine component (a2), the usage of the other diamine compound (a2-5) may be 5 mol to 99 mol, preferably 10 mol to 52 mol, and more preferably 15 mol to 37 mol.

[0126] Polymer (B)

[0127] In addition to the aforementioned polymer (A), the liquid crystal alignment agent of the present invention may also selectively contain a polymer (B) selected from the group consisting of a polyimide precursor obtained by using a tetracarboxylic acid derivative component (b1) and a diamine component (b2), and an imidized polymer (i.e., polyimide) of the polyimide precursor. For example, the polymer (B) may include, but is not limited to, at least one polymer selected from the group consisting of a polyimide precursor obtained by reacting a tetracarboxylic acid derivative component (b1) and a diamine component (b2) that does not contain the above-mentioned specific diamine compound (such as the diamine compound (a2-1) shown in formula (A21)) and an imidized product (i.e., polyimide) of the polyimide precursor. Specific examples of the above-mentioned polyimide precursor may include, for example, polyamic acid or polyamic acid ester. The polymer (B) may be used alone or in combination. The usage ratio of polymer (A) to polymer (B) (ie, the mass ratio of [polymer (A)] / [polymer (B)]) may be 10 / 90 to 90 / 10, preferably 20 / 80 to 90 / 10, and more preferably 20 / 80 to 80 / 20.

[0128] Tetracarboxylic acid derivative component (b1)

[0129] The tetracarboxylic acid derivative component (b1) used to obtain the polymer (B) may include, for example, but not limited to, a non-cyclic aliphatic tetracarboxylic acid dianhydride compound, an alicyclic tetracarboxylic acid dianhydride compound, an aromatic tetracarboxylic acid dianhydride compound, or derivatives of these compounds. Specific examples of non-cyclic aliphatic tetracarboxylic acid dianhydride compounds, alicyclic tetracarboxylic acid dianhydride compounds, and aromatic tetracarboxylic acid dianhydride compounds may include, for example, the tetracarboxylic acid dianhydride compounds exemplified by the aforementioned polymer (A). Preferably, the tetracarboxylic acid derivative component (b1) may include an alicyclic tetracarboxylic acid dianhydride or its derivative (a1-1) as shown in the above formula (A11), or a tetracarboxylic acid dianhydride compound or its derivative as shown in the above formula (A12) and X1' represents a structure shown in formula (A12-1) to formula (A12-6). The tetracarboxylic acid derivative component (b1) may be used alone or in combination.

[0130] The tetracarboxylic acid derivative component (b1) preferably comprises a tetracarboxylic dianhydride compound (hereinafter referred to as a tetracarboxylic dianhydride compound (b1-1)) represented by the above formula (A12) and X1′ represents a structure represented by the following formula (A12-33).

[0131]

[0132] In the formula (A12-33), Z 11 represents a single bond; and “*” represents a bonding position.

[0133] The aforementioned tetracarboxylic dianhydride compound (b1-1) may be used alone or in combination of two or more.

[0134] More preferably, the tetracarboxylic acid derivative component (b1) comprises a tetracarboxylic dianhydride compound represented by the following formula (B11).

[0135]

[0136] Based on 100 mol of the total usage of the tetracarboxylic acid derivative component (b1), the usage of the tetracarboxylic dianhydride compound (b1-1) may be 30 mol to 100 mol, preferably 40 mol to 100 mol, and more preferably 50 mol to 100 mol.

[0137] Diamine component (b2)

[0138] The diamine component (b2) used to obtain the polymer (B) may, for example, include but is not limited to the aforementioned diamine component (a2), or a diamine compound having at least one nitrogen-containing atom structure selected from the group consisting of a nitrogen-containing heterocyclic ring, a secondary amine group and a tertiary amine group (hereinafter referred to as diamine compound (b2-1)), but the diamine component (b2) does not include the aforementioned diamine compound (a2-1).

[0139] The diamine component (b2) can be used alone or in combination of two or more.

[0140] Diamine compound (b2-1)

[0141] The diamine compound (b2-1) having the above-mentioned specific nitrogen-containing atom structure may have a nitrogen-containing heterocyclic ring, for example, pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, tantalum, , pyridine , indole, benzimidazole, purine, quinoline, isoquinoline, Pyridine, quinone Linole ,three , carbazole, acridine, piperidine, piperidine , pyrrolidine or hexamethyleneimine, etc. Among them, pyridine, pyrimidine, pyrrolidine, , piperidine, piperidine , quinoline, carbazole or acridine is preferred.

[0142] The diamine compound (b2-1) having the above-mentioned specific nitrogen atom-containing structure may include a secondary amine group and a tertiary amine group as represented by the following formula (B21).

[0143]

[0144] In formula (B21), Z represents a hydrogen atom or an alkyl group, a cycloalkyl group or an aryl group having 1 to 10 carbon atoms; "*" represents the bonding position of the hydrocarbon group.

[0145] The alkyl represented by Z may include, but not limited to, methyl, ethyl or propyl; the cycloalkyl represented by Z may include, but not limited to, cyclohexyl; the aryl represented by Z may include, but not limited to, phenyl or tolyl. Z is preferably a hydrogen atom or a methyl group.

[0146] Specific examples of the diamine compound (b2-1) having the above-mentioned specific nitrogen-containing atom structure include: 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperidin , 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, diamine compounds as shown in the following formulas (B21-1) to (B21-8), or diamine compounds as shown in the following formulas (B21-9) to (B21-26).

[0147]

[0148]

[0149]

[0150]

[0151] The diamine compound (b2-1) may be used alone or in combination of two or more.

[0152] Based on 100 mol of the total usage of the diamine component (b2), the usage of the diamine compound (b2-1) may be 15 mol to 100 mol, preferably 20 mol to 90 mol, and more preferably 25 mol to 80 mol.

[0153] Method for making polymer

[0154] The manufacture of polymer (A) or polymer (B) can be carried out by reacting the aforementioned diamine component and tetracarboxylic acid derivative component in a solvent (condensation polymerization). When a part of polymer (A) or polymer (B) has an amic acid structure, for example, by reacting the tetracarboxylic acid derivative component with the diamine component, a polymer having an amic acid structure (i.e., polyamic acid) is obtained. The aforementioned solvent is not particularly limited, and it only needs to be able to dissolve the formed polymer. For example, specific examples of solvents may include but are not limited to N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide or 1,3-dimethyl-2-imidazolidinone. In some specific examples, when the solvent solubility of the polymer is high, the solvent may include methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or a solvent as shown in the following formula (D-1) to formula (D-3). In formula (D-1), Z1 represents an alkyl group having 1 to 3 carbon atoms. In formula (D-2), Z2 represents an alkyl group having 1 to 3 carbon atoms. In formula (D-3), Z3 represents an alkyl group having 1 to 4 carbon atoms.

[0155]

[0156] The aforementioned solvents can be used alone or in combination. Secondly, even if the solvent is insoluble in the polymer, it can still be mixed with the above-mentioned solvent within the range that the generated polymer will not precipitate. When the diamine component and the tetracarboxylic acid derivative component react in the solvent, the reaction can be carried out at any concentration, but preferably 1wt% to 50wt%, and more preferably 5wt% to 30wt%. The reaction can also be carried out at a high concentration initially, and then additional solvent is added. When reacting, the ratio of the total molar number of the diamine component to the total molar number of the tetracarboxylic acid derivative component is preferably 0.8 to 1.2. Similar to the general polycondensation reaction, the closer this molar ratio is to 1.0, the greater the molecular weight of the polymer (A) or polymer (B) formed.

[0157] The polymer having an amide ester structure can be obtained, for example, by the following known methods: (1) a method in which the polyamide acid obtained by the above method is further reacted with an esterifying agent, (2) a method in which a tetracarboxylic acid diester compound is reacted with a diamine compound, or (3) a method in which a tetracarboxylic acid diester dihalide is reacted with a diamine compound.

[0158] The imide compound in the polymer (A) or polymer (B) contained in the liquid crystal alignment agent of the present invention can be obtained, for example, by subjecting the polymer obtained above to a dead cycle. In the imide compound, the dead cycle rate (also referred to as the imidization rate) of the functional group possessed by the amic acid group or its derivative does not necessarily have to be 100%, and the imidization rate can be arbitrarily adjusted according to the use and / or purpose. The method for obtaining the imide compound can be, for example, thermal imidization in which the polymer solution obtained by the above reaction is directly heated, or catalytic imidization in which a catalyst is added to the polymer solution. When thermal imidization is performed in the solution, the temperature is preferably 100°C to 400°C, and more preferably 120°C to 250°C. When thermal imidization is performed, it is preferred to discharge the water generated by the imidization reaction to the outside of the system.

[0159] The aforementioned catalytic imidization can be carried out, for example, by adding an alkaline catalyst and anhydride to the polymer solution obtained by the reaction, preferably at -20°C to 250°C, and more preferably at 0°C to 180°C for stirring. The amount of alkaline catalyst added is preferably 0.5 to 30 moles of the amide acid group, and more preferably 2 to 20 moles; the amount of anhydride added is preferably 1 to 50 moles of the amide acid group, and more preferably 3 to 30 moles. Specific examples of alkaline catalysts may include but are not limited to pyridine, triethylamine, trimethylamine, tributylamine or trioctylamine. Among them, pyridine is more ideal because it has a moderate alkalinity that allows the reaction to proceed. Specific examples of anhydrides may include but are not limited to acetic anhydride, trimellitic anhydride or benzene tetracarboxylic anhydride. Among them, if acetic anhydride is used, purification after the reaction is easier, so it is more ideal. The imidization rate of the catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature and / or reaction time. When the imide formed is recovered from the reaction solution of the above-mentioned imidization, the reaction solution is put into a solvent and precipitated. The solvent used for precipitation may include, but is not limited to, methanol, ethanol, isopropanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene or water. After filtering and recovering the polymer precipitated by the solvent, it can be dried at normal pressure or reduced pressure, at room temperature or by heating. Alternatively, the polymer recovered by precipitation is dissolved in a solvent again, and reprecipitation is carried out for recovery, and this operation is repeated 2 to 10 times to reduce impurities in the polymer. The solvent used may be, for example, alcohols or ketone hydrocarbons. If used in three or more solvents selected therein, the efficiency of refining can be further improved, so it is more ideal.

[0160] Solution viscosity and molecular weight of polymers

[0161] When the solution is prepared into a concentration of 10 wt% to 15 wt%, the solution concentration of the polymer (A) or polymer (B) of the present invention is not particularly limited. Based on the viewpoint of easier operation, the solution concentration can be, for example, 10 mPa·s to 1000 mPa·s. The solution viscosity (mPa·s) of the polymer is a value measured at 25°C using a good solvent for the polymer (e.g., γ-butyrolactone or N-methyl-2-pyrrolidone, etc.) to prepare a polymer solution with a concentration of 10 wt% to 15 wt%.

[0162] The weight average molecular weight (M) of the polymer (A) or (B) of the present invention measured by gel permeation chromatography (GPC) in terms of polystyrene is w ) is preferably 1,000 to 500,000, and more preferably 2,000 to 500,000. w The number average molecular weight (M) of the polystyrene was measured by GPC. n ) ratio represents the molecular weight distribution (M w / M n ) is preferably less than 15, and more preferably less than 10. When the molecular weight of the polymer is within the aforementioned molecular weight range, it can ensure good orientation and stability of the liquid crystal display device.

[0163] Capping agent

[0164] When synthesizing the polymer (A) or polymer (B) of the present invention, the tetracarboxylic acid derivative component and the diamine component as described above can be used, and an appropriate end-capping agent can be used to synthesize an end-sealed polymer. The end-sealed polymer has the effect of improving the film hardness of the liquid crystal alignment film obtained by using the coating, and improving the sealing properties of the sealant and the liquid crystal alignment film. The end of the polymer (A) or polymer (B) of the present invention may, for example, contain an amine group, a carboxyl group, an anhydride group or a derivative thereof. The amine group, the carboxyl group, the anhydride group or a derivative thereof can be obtained by a general condensation reaction, or by using the end-capping agent described later to seal the end. Similarly, the aforementioned derivatives can be obtained, for example, using the following end-capping agent.

[0165] For example, the end-capping agent may include, but is not limited to, acetic anhydride, maleic anhydride, neddic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-((3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione or 4-ethynylphthalic anhydride; dibutyl dicarbonate or diallyl dicarbonate; Carbonic acid diester compounds; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride or nicotinyl chloride; monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine or n-octylamine; monoisocyanate compounds such as ethyl isocyanate, phenyl isocyanate or naphthyl isocyanate, etc.

[0166] The blocking agents may be used alone or in combination of two or more.

[0167] Based on 100 mol parts of the total usage of the diamine component, the usage of the end-capping agent is preferably 0.01 mol parts to 20 mol parts, and more preferably 0.01 mol parts to 10 mol parts.

[0168] Other ingredients in liquid crystal alignment agents

[0169] The liquid crystal alignment agent of the present invention may include a polymer (A) and a polymer (B) added as needed. In addition to the polymer (A) and the polymer (B), the liquid crystal alignment agent of the present invention may selectively include other polymers. The types of other polymers may include, for example, but are not limited to, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetals, polystyrene or its derivatives, poly(styrene-phenylmaleimide) derivatives, or poly(meth)acrylates.

[0170] Solvent (C)

[0171] Based on the viewpoint of forming a uniform film, the liquid crystal alignment agent takes the form of a coating liquid to prepare a liquid crystal alignment film. The liquid crystal alignment agent of the present invention is preferably a coating liquid containing the above-mentioned polymer component and an organic solvent (hereinafter referred to as solvent (C)). Among them, based on the set coating thickness to be formed, the polymer concentration in the liquid crystal alignment agent can be appropriately changed. Based on the viewpoint of forming a uniform and defect-free coating film, the polymer concentration in the liquid crystal alignment agent is preferably above 1wt%. Based on the viewpoint of the storage stability of the solution, the polymer concentration in the liquid crystal alignment agent is preferably below 10wt%. The ideal polymer concentration can be from 2wt% to 8wt%. The content of polymer (A) in the liquid crystal alignment agent can be appropriately changed by the coating method of the liquid crystal alignment agent and / or the film thickness of the desired liquid crystal alignment film, and it can preferably be from 2wt% to 10wt%, and more preferably from 3wt% to 7wt%. There is no special restriction on the organic solvent contained in the liquid crystal alignment agent, and it only needs to be able to uniformly dissolve the aforementioned polymer. Specific examples thereof may include, but are not limited to, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone or N-cyclohexyl-2-pyrrolidone, etc., and the aforementioned organic solvents are also called good solvents. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide or γ-butyrolactone is preferred. Based on 100 wt % of the total amount of the solvent in the liquid crystal alignment agent, the amount of the good solvent may be 20 wt % to 99 wt %, preferably 20 wt % to 90 wt %, and more preferably 30 wt % to 80 wt %.

[0172] Secondly, the organic solvent in the liquid crystal alignment agent is preferably a mixed solvent of the aforementioned solvent and a solvent (also referred to as a poor solvent) that can improve the coating properties of the liquid crystal alignment agent and the surface smoothness of the coating film. The specific poor solvent used in combination may be, for example, but not limited to, the solvent described below. Based on the total amount of solvents used in the liquid crystal alignment agent being 100wt%, the amount of the poor solvent used is preferably 1wt% to 80wt%, more preferably 10wt% to 80wt%, and particularly preferably 20wt% to 70wt%. The type and amount of the poor solvent used can be appropriately selected based on the coating device, coating conditions and / or coating environment of the liquid crystal alignment agent. For example, the poor solvent may be, for example, diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethyl carbonate, ethylene glycol monobutyl ether (butyl cellulose), ethylene glycol monoisopentyl ether, ethylene glycol monohexyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy) )-2-propanol, 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isopentyl lactate, diethylene glycol monoethyl ether, or diisobutyl ketone (2,6-dimethyl-4-heptanone), etc.

[0173] Among them, diisobutyl carbinol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone is preferred.

[0174] The solvent combination of good solvent and poor solvent can be preferably, for example, but not limited to, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether; N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether; N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone; N-ethyl-2-pyrrolidone and propylene glycol diacetate; N,N-dimethyl lactamide and diisobutyl ketone; N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate; N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate; N-methyl-2-pyrrolidone and ethyl Glycol monobutyl ether acetate; N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether; N,N-dimethyl lactamide and ethylene glycol monobutyl ether; N,N-dimethyl lactamide and propylene glycol diacetate; N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether; N,N-dimethyl lactamide and diethylene glycol diethyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether; N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone; N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, 4-Hydroxy-4-methyl-2-pentanone and diisobutyl ketone; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate; γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone; γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisobutyl ketone; N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol diacetate Glycol monobutyl ether and diisopropyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisobutyl carbinol; N-methyl-2-pyrrolidone, γ-butyrolactone and dipropylene glycol dimethyl ether; N-methyl-2-pyrrolidone, propylene glycol monobutyl ether and dipropylene glycol dimethyl ether; N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether and dipropylene glycol monomethyl ether; N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether and propylene glycol diacetate; N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether and diisobutyl ketone; N-ethyl-2-pyrrolidone, γ-butyrolactone and diisobutyl ketone; or N-ethyl-2-pyrrolidone, N,N-dimethyl lactamide and diisobutyl ketone, etc.

[0175] The aforementioned solvent (C) may be used alone or in combination of two or more.

[0176] Based on 100 parts by weight of the total amount of polymer (A) and polymer (B), the amount of solvent (C) used may be 800 to 4000 parts by weight, preferably 900 to 3500 parts by weight, and more preferably 1000 to 3000 parts by weight.

[0177] additive

[0178] The liquid crystal alignment agent of the present invention may also selectively add components other than the polymer component and the organic solvent (hereinafter referred to as additive components). These additive components may include, for example, but are not limited to: a bonding aid for improving the adhesion between the liquid crystal alignment film and the substrate or the adhesion between the liquid crystal alignment film and the sealant, a compound for improving the strength of the liquid crystal alignment film (hereinafter referred to as a cross-linking compound), a compound for promoting imidization, a dielectric or conductive substance for adjusting the dielectric constant or resistance of the liquid crystal alignment film, etc.

[0179] Sealing agent

[0180] The aforementioned adhesion aid may be, for example, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-aminopropyl diethoxymethyl silane, 2-aminopropyl trimethoxysilane, 2-aminopropyl triethoxysilane, N-(2-aminoethyl)-3-aminopropyl trimethoxysilane, N-(2-aminoethyl)-3-aminopropyl methyl dimethoxysilane, 3-ureidopropyl trimethoxysilane, 3-ureidopropyl triethoxysilane, N-ethoxycarbonyl-3-aminopropyl trimethoxysilane, N-ethoxycarbonyl-3-aminopropyl triethoxysilane, N-triethoxysilylpropyl triethylene triamine, N-trimethoxysilylpropyl triethylene triamine, vinyl trimethoxysilane, Silane coupling agents include silane, vinyl triethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, 3-glycidoxypropyl methyl dimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyl diethoxysilane, 3-glycidoxypropyl triethoxysilane, 3-methacryloxypropyl methyl dimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl methyl diethoxysilane, 3-methacryloxypropyl triethoxysilane, 3-acryloxypropyl trimethoxysilane, tris(3-trimethoxysilylpropyl) isocyanurate, or 3-isocyanate propyl triethoxysilane. When using a bonding aid, based on the viewpoint of exhibiting good resistance to AC image sticking, the amount of the bonding aid used is preferably 0.1 to 30 parts by weight, and more preferably 0.1 to 20 parts by weight, relative to 100 parts by weight of the total amount of the polymer used in the liquid crystal alignment agent.

[0181] Cross-linking compound For the aforementioned cross-linking compound, based on the viewpoint of exhibiting good resistance to AC image sticking and effectively improving film strength, it can be a compound having an ethylene oxide group, a propylene oxide group, at least one group selected from the group consisting of a group represented by the following formula (E1) and a group represented by the following formula (E2), or a compound selected from the compound represented by the following formula (E3).

[0182]

[0183] In formula (E1), G1 and G2 each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or -CH2-OH. In formula (E2), G3 represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms. G4 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms. In formula (E3), G5 represents a (g1+g2)-valent organic group containing an aromatic ring. G6 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. g1 represents an integer from 1 to 6, and g2 represents an integer from 0 to 4. In formula (E3), the (g1+g2)-valent organic group having an aromatic ring represented by G5 may be a (g1+g2)-valent aromatic hydrocarbon group having 6 to 30 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms directly or through a linking group, or a (g1+g2)-valent group having an aromatic heterocycle. The aromatic hydrocarbon may be, for example, benzene or naphthalene. The aromatic heterocycle may be exemplified by the aromatic heterocycles of the above-mentioned specific nitrogen-containing atom structure. The linking group may be an alkylene group having 1 to 10 carbon atoms or a group that removes a hydrogen atom from the alkylene group, or a divalent or trivalent cyclohexane. Among them, any hydrogen atom of the alkylene group may also be substituted by an organic group such as a fluorine atom or a trifluoromethyl group. In formula (E3), the alkyl group having 1 to 5 carbon atoms represented by G6 may be methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl or n-pentyl.

[0184] Compounds with ethylene oxide

[0185] Specific examples of the compound having an oxirane group include N,N,N',N'-tetracyclyl-m-xylene diamine, 1,3-bis(N,N-dicyclylaminomethyl)cyclohexane, N,N,N',N'-tetracyclyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetracyclyl-p-phenylenediamine, and compounds containing a nitrogen atom such as those represented by the following formulas (E4) to (E6).

[0186]

[0187]

[0188] Compounds having propylene oxide groups

[0189] Specific examples of the compound having an propylene oxide group include compounds represented by the following formula (E7) to formula (E16).

[0190]

[0191]

[0192]

[0193] In formula (E15), R represents The “*” represents the bonding position.

[0194] Compounds having a group represented by formula (E1)

[0195] Specific examples of the compound having a group represented by the formula (E1) include compounds represented by the following formulas (E1-1) to (E1-12).

[0196]

[0197]

[0198]

[0199] Compounds Having a Group Represented by Formula (E2) Specific examples of compounds having a group represented by formula (E2) include compounds represented by the following formulae (E2-1) to (E2-4).

[0200]

[0201] Compounds having a group represented by formula (E3)

[0202] Specific examples of the compound having a group represented by formula (E3) include compounds represented by the following formulas (E3-1) to (E3-10).

[0203]

[0204]

[0205] In the liquid crystal alignment agent of the present invention, based on the total amount of the polymer in the liquid crystal alignment agent being 100 parts by weight, the amount of the crosslinking compound used is preferably 0.5 parts by weight to 20 parts by weight. In particular, based on the viewpoint of the crosslinking reaction and the good resistance to AC image sticking, the amount of the crosslinking compound used is more preferably 1 part by weight to 15 parts by weight.

[0206] Compounds that promote imidization

[0207] The aforementioned compound for promoting imidization is preferably a compound having a basic site (for example: a primary amine group, an aliphatic heterocycle (such as a pyrrolidine skeleton), an aromatic heterocycle (such as an imidazole ring or an indole ring), or a guanidine group, etc.) (except for the above-mentioned cross-linking compound and the close-fitting aid), or a compound that produces the basic site when calcined. More preferably, the compound that promotes imidization is a compound that produces the basic site when calcined, and a specific example thereof may be an amino acid in which part or all of the basic sites possessed by the amino acid are protected. Specific examples of the above-mentioned amino acids include glycine, alanine, cysteine, methionine, asparagine, glutamic acid, valine, leucine, phenylalanine, tyrosine, tryptophan, proline, hydroxyproline, arginine, histidine, lysine, or ornithine. For the purpose of promoting the imidization compound, a more preferable specific example is N-α-(9-fluorenylmethoxycarbonyl)-N-τ-(tert-butoxycarbonyl)-L-histidine.

[0208] Liquid crystal alignment film and method for manufacturing liquid crystal display component

[0209] The liquid crystal alignment film of the present invention is obtained from the aforementioned liquid crystal alignment agent. The liquid crystal alignment film of the present invention can be used as a horizontal alignment type or a vertical alignment type (VA type) liquid crystal alignment film, and it is a liquid crystal alignment film suitable for a horizontal alignment type liquid crystal display component such as an IPS mode or a FFS mode. The liquid crystal display component of the present invention has the aforementioned liquid crystal alignment film. The liquid crystal display component of the present invention can be produced, for example, by the following steps (1) to step (4) or steps (1) to step (2) and step (4).

[0210] Step (1): Applying a liquid crystal alignment agent onto a substrate

[0211] The liquid crystal alignment agent of the present invention is applied to one side of a substrate provided with a patterned transparent conductive film by using an appropriate coating method such as roller coating, spin coating, printing or inkjet. There is no particular limitation on the substrate, which only needs to be a highly transparent substrate. A glass substrate or a silicon nitride substrate can also be used in combination with a plastic substrate such as an acrylic substrate or a polycarbonate substrate. Secondly, in a reflective liquid crystal display component, if only a single-sided substrate is used, an opaque material such as a silicon wafer can also be used, and the electrode used can also be a light-reflecting material such as aluminum. Furthermore, when making an IPS-type or FFS-type liquid crystal component, the comb-tooth type uses an electrode substrate composed of a patterned transparent conductive film or metal film and an opposing substrate without an electrode.

[0212] The method of coating the liquid crystal alignment agent on the substrate to form a film may include screen printing, lithography, flexographic printing, inkjet method or spray coating method, etc. Among them, the film forming method is preferably coating by inkjet method.

[0213] Step (2): calcining the coated liquid crystal alignment agent

[0214] Step (2) is a step of calcining the liquid crystal alignment agent applied on the substrate to form a film. After the liquid crystal alignment agent is applied on the substrate, the solvent can be evaporated by heating means such as a hot plate, a heat circulation oven or an IR (infrared) oven, or thermal imidization of polyamic acid or polyamic acid ester can be performed. The drying and calcining steps performed after the liquid crystal alignment agent of the present invention has been applied can select any temperature and time, and multiple drying or calcining steps can be performed. The drying temperature can be, for example, 40°C to 180°C. From the perspective of shortening the process, it can be performed at 40°C to 150°C. The drying time is not particularly limited, and it can be, for example, 1 minute to 10 minutes or 1 minute to 5 minutes. When thermal imidization of polyamic acid or polyamic acid ester is performed, after the aforementioned drying step, a calcination step can be further performed at a temperature of, for example, 150°C to 300°C or 150°C to 250°C. The calcination time is not particularly limited, and may be 5 to 40 minutes or 5 to 30 minutes. If the film after calcination is too thin, the reliability of the liquid crystal display device will be reduced, so the film thickness is preferably 5 nm to 300 nm, and more preferably 10 nm to 200 nm.

[0215] Step (3): Alignment treatment of the film obtained in step (2) Step (3) is to perform alignment treatment on the film obtained in step (2) as appropriate. In other words, in a horizontal alignment type liquid crystal display component such as an IPS mode or an FFS mode, the coating film is subjected to an alignment treatment to impart alignment capability. On the other hand, in a vertical alignment type liquid crystal display component such as a VA mode or a PSA mode, the formed coating film can be used directly as a liquid crystal alignment film, but the coating film can also be subjected to an alignment treatment to impart alignment capability. The alignment treatment of the liquid crystal alignment film can include a friction treatment method or a photo alignment treatment method, preferably a photo alignment treatment method. The photo alignment treatment method can include a method in which the surface of the above-mentioned film-like object is irradiated with radiation that has been deflected in a certain direction, and, as appropriate, preferably heated at a temperature of 150°C to 250°C to impart liquid crystal alignment (also referred to as liquid crystal alignment capability). The radiation can use ultraviolet rays or visible light with a wavelength of 100nm to 800nm. Among them, the radiation is preferably ultraviolet light having a wavelength of 100 nm to 400 nm, and more preferably ultraviolet light having a wavelength of 200 nm to 400 nm.

[0216] The radiation dose can be 1mJ / cm 2 Up to 10,000mJ / cm 2 , preferably 100mJ / cm 2 Up to 5,000mJ / cm 2 , preferably 100 mJ / cm 2 Up to 1500mJ / cm2 , and preferably 100 mJ / cm 2 Up to 1000mJ / cm 2 When using a general liquid crystal alignment agent, the light exposure for the alignment treatment is 100mJ / cm 2 Up to 5000mJ / cm 2 However, the liquid crystal alignment agent of the present invention can obtain a liquid crystal alignment film in which the variation (non-uniformity) of the liquid crystal alignment within the film surface is effectively suppressed even if the amount of light irradiation in the alignment treatment is reduced. When irradiating radiation, in order to improve the liquid crystal alignment, the substrate of the aforementioned film-like object can be heated at 50°C to 250°C while irradiating. The liquid crystal alignment film produced in this way can stably align the liquid crystal molecules in a certain direction. Secondly, the liquid crystal alignment film that has been irradiated with polarized radiation in the aforementioned method can be contact-treated with a solvent, or the liquid crystal alignment film that has been irradiated with radiation can be heat-treated.

[0217] The solvent used in the above-mentioned contact treatment is not particularly limited, and it only needs to be able to dissolve the decomposition products generated from the film after irradiation with radiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellulose, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, or cyclohexyl acetate. Among them, based on the viewpoint of versatility and safety, water, 2-propanol, 1-methoxy-2-propanol or ethyl lactate are preferred, and water, 1-methoxy-2-propanol or ethyl lactate are more preferred. The solvent can be used alone or in combination. The temperature for heating the above-mentioned coating film irradiated with radiation is preferably 50°C to 300°C, and more preferably 120°C to 250°C. The heating treatment time is preferably 1 minute to 30 minutes.

[0218] Step (4): Making liquid crystal cells

[0219] Two liquid crystal alignment film substrates formed as described above are prepared, and liquid crystal is arranged between the two substrates arranged facing each other. For example, the following two methods can be cited. In the first method, the two substrates are arranged facing each other with a gap (cell gap) between them in a manner that the liquid crystal alignment films face each other. Then, the peripheral portions of the two substrates are bonded together with a sealant, and then the liquid crystal composition is injected and filled into the cell gap separated by the substrate surface and the sealant, and after it contacts the film surface, the injection hole is sealed.

[0220] The second method is a method called ODF (One Drop Fill). A sealant such as a UV-curable sealant is applied to a predetermined position of one of the two substrates on which a liquid crystal alignment film has been formed, and then a liquid crystal composition is dripped at multiple predetermined positions on the surface of the liquid crystal alignment film. Then, the other substrate is attached in a manner that the liquid crystal alignment films face each other, and the liquid crystal composition is pushed on the entire surface of the substrate so that it contacts the film surface. Next, ultraviolet light is irradiated on the entire surface of the substrate to harden the sealant. When any of the aforementioned methods is performed, it is preferred to further heat the liquid crystal composition used to a temperature at which it becomes an isotropic phase, and then slowly cool it to room temperature to remove the flow alignment during liquid crystal filling. Secondly, when the coating is subjected to friction treatment, the two substrates are arranged to face each other at a predetermined angle with the friction directions of each coating, for example, in a manner of orthogonal or antiparallel. The sealant may be, for example, an epoxy resin containing a hardener and aluminum oxide balls as spacers. The liquid crystal composition may include nematic liquid crystals and smectic liquid crystals, and nematic liquid crystals are preferred.

[0221] If necessary, a polarizing plate can be attached to the outer surface of the liquid crystal cell to obtain a liquid crystal display device. The polarizing plate attached to the outer surface of the liquid crystal cell can be a polarizing film called "H film" that stretches polyvinyl alcohol and absorbs iodine. It can be a polarizing plate sandwiched by a cellulose acetate protective film, or a polarizing plate composed of the H film itself.

[0222] The following embodiments are used to illustrate the application of the present invention, but they are not used to limit the present invention. Anyone skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0223] none DETAILED DESCRIPTION

[0224] Preparation of diamine compound (a2-1)

[0225] Synthesis Example a2-1-1

[0226] 27.39 g (0.18 mol) of 1-phenyl-1,3-propanediol was mixed with 14.2 g (0.18 mol) of pyridine, and the mixture was dissolved in 60 g of toluene, and 85.08 g (0.54 mol) of 4-nitrochlorobenzene was added to form a reaction solution. The reaction solution was reacted at 25 ° C for 6 hours. The reaction solution was then mixed with 200 ml of pure water, purified and concentrated to obtain a solid product. Afterwards, the solid product was crystallized using methanol to form a powdered intermediate product of Synthesis Example a2-1-1.

[0227] Next, the aforementioned intermediate product was dissolved in 40 grams of toluene. The solution temperature was maintained at 5°C, 0.02 grams of 10% palladium carbon (Pd-C) was added to the solution as a catalyst, and 4.8 grams of hydrazine was slowly added dropwise, and then reacted at 165°C. After reacting for 8 hours, the reaction solution was mixed with 100 ml of water, and purified and concentrated to obtain a solid product. Afterwards, the solid product was crystallized using methanol. The resulting powdered product was collected and recrystallized with toluene to obtain a white powder product of the synthesis example a2-1-1 shown in formula (A21-2).

[0228] Synthesis Example a2-1-2 to Synthesis Example a2-1-6

[0229] Synthesis Examples a2-1-2 to a2-1-6 use the same preparation method as the preparation method of the diamine compound (a2-1) in Synthesis Example 2-1-1, except that the types of reactants are changed as follows in Synthesis Examples a2-1-2 to a2-1-6.

[0230] In synthesis example a2-1-2, 2-cyclohexyl-1,4-butanediol is used to replace 1-phenyl-1,3-propanediol, and p-fluoronitrobenzene is used to replace 4-nitrochlorobenzene, and the obtained product has a structure as shown in formula (A21-3).

[0231] In synthesis example a2-1-3, 2-n-pentyl-1,4-butanediol is used to replace 1-phenyl-1,3-propanediol, and the obtained product has a structure as shown in formula (A21-5).

[0232] In synthesis example a2-1-4, 6-methyl-1,4-heptanediol is used to replace 1-phenyl-1,3-propanediol, and p-fluoronitrobenzene is used to replace 4-nitrochlorobenzene, and the obtained product has a structure as shown in formula (A21-7).

[0233] In synthesis example a2-1-5, 1,2-propylene glycol is used to replace 1-phenyl-1,3-propylene glycol, and p-fluoronitrobenzene is used to replace 4-nitrochlorobenzene, and the obtained product has a structure as shown in formula (A21-8).

[0234] In synthesis example a2-1-6, 2-ethyl-1,3-propanediol is used to replace 1-phenyl-1,3-propanediol, and the obtained product has a structure as shown in formula (A21-9).

[0235] Preparation of polymer (A)

[0236] Synthesis Example A-1-1

[0237] A nitrogen inlet, a stirrer, a condenser and a thermometer were set on a 500 ml four-necked conical flask, and nitrogen was introduced. Then, 1.355 g (0.00525 mol) of the diamine compound (a2-1-5) obtained in Synthesis Example a2-1-5, 1.764 g (0.00525 mol) of the diamine compound (a2-2-1) shown in Formula (A22-7), 3.042 g (0.0045 mol) of the diamine compound (a2-3-1) and 80 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) were added, and stirred at room temperature until dissolved. Next, 3.36 g (0.015 mol) of the compound (a1-1-1) and 20 g of NMP were added, and the mixture was reacted at room temperature for 2 hours. After the reaction, the reaction solution was poured into 1500 ml of water to precipitate the polymer, and the obtained polymer was filtered, and the steps of washing and filtering were repeated three times with methanol. After that, the product was placed in a vacuum oven and dried at a temperature of 60° C. to obtain the polymer (A-1-1) of Synthesis Example A-1-1, whose formula is shown in Table 1.

[0238] Synthesis Example A-1-2 to Synthesis Example A-1-20 and Comparative Synthesis Example A-1-21 to Comparative Synthesis Example A-1-26

[0239] Synthesis Examples A-1-2 to A-1-20 and Comparative Synthesis Examples A-1-21 to A-1-26 use the same preparation method as the method for making the polymer (A-1-1) of Synthesis Example A-1-1, the difference being that Synthesis Examples A-1-2 to A-1-20 and Comparative Synthesis Examples A-1-21 to A-1-26 change the type and amount of raw materials in the polymer, and their formulas are shown in Table 1 and are not described in detail here.

[0240] Synthesis Example A-2-1

[0241] A nitrogen inlet, a stirrer, a condenser and a thermometer were set on a 500 ml four-necked conical flask, and nitrogen was introduced. Then, 1.355 g (0.00525 mol) of the diamine compound (a2-1-5) obtained in Synthesis Example a2-1-5, 1.764 g (0.00525 mol) of the diamine compound (a2-2-1) shown in Formula (A22-7), 3.042 g (0.0045 mol) of the diamine compound (a2-3-1) and 80 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) were added, and stirred at room temperature until dissolved. Next, 3.36 g (0.015 mol) of the compound (a1-1-1) and 20 g of NMP were added. After reacting at room temperature for 6 hours, 97 g of NMP, 2.55 g of acetic anhydride and 19.75 g of pyridine were added, the temperature was raised to 60°C, and stirring was continued for 2 hours to carry out imidization reaction. After the reaction was completed, the reaction solution was poured into 1500 ml of water to precipitate the polymer. Then, the obtained polymer was filtered, and the washing and filtering with methanol were repeated three times, and placed in a vacuum oven and dried at a temperature of 60°C to obtain a polymer (A-2-1), the formula of which is shown in Table 1.

[0242] Synthesis Example A-2-2 to Synthesis Example A-2-4

[0243] Synthesis Examples A-2-2 to A-2-4 use the same preparation method as the preparation method of the polymer (A-2-1) in Synthesis Example A-2-1, the difference being that Synthesis Examples A-2-2 to A-2-4 change the type and amount of raw materials in the polymer, and their formulas are shown in Table 1 and are not further described here.

[0244]

[0245] Preparation of polymer (B)

[0246] Synthesis Example B-1-1 to Synthesis Example B-1-3

[0247] Synthesis Examples B-1-1 to B-1-3 are prepared using the same method as the method for preparing the polymer (A-1-1) of Synthesis Example A-1-1, except that the types and amounts of raw materials used in the polymers are changed in Synthesis Examples B-1-1 to B-1-3. The formulas are shown in Table 2, and are not described here. Synthesis Examples B-2-1 to B-2-3

[0248] Synthesis Examples B-2-1 to B-2-3 are prepared by the same method as the method for preparing the polymer (A-2-1) of Synthesis Example A-2-1, except that the types and amounts of raw materials used in the polymers are changed in Synthesis Examples B-2-1 to B-2-3. The formulas are shown in Table 2, and are not described here.

[0249] Table 2

[0250]

[0251]

[0252] Preparation of liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display component

[0253] Example 1

[0254] Weigh 50 parts by weight of the polymer (A-1-1) prepared in Synthesis Example A-1-1, 50 parts by weight of the polymer (B-1-1) prepared in Synthesis Example B-1-1, and 1600 parts by weight of NMP (C-1), and stir and mix them at room temperature to obtain the liquid crystal alignment agent of Example 1.

[0255] The liquid crystal alignment agent prepared above is spin-coated on a glass substrate, and a pixel electrode is formed on the glass substrate, wherein the pixel electrode is an IPS driving electrode having a pair of ITO electrodes (electrode width is 10 μm, electrode interval is 10 μm, and electrode height is 50 nm), and the pair of ITO electrodes are respectively in a comb-like shape, and the comb-like parts of each other are configured in a separated and biting manner. Then, the glass substrate coated with the liquid crystal alignment agent is dried on a hot plate at 80°C for 3 minutes, and then baked in a hot air circulation oven at 250°C for 30 minutes to form a coating film with a thickness of 100 nm.

[0256] After irradiating the coating surface with ultraviolet light having a wavelength of 254 nm through a polarizing plate, the substrate was baked in a hot air circulation oven at 250° C. for 30 minutes to obtain a substrate having a liquid crystal alignment film. Similarly, a coating film was formed on an opposing substrate and an alignment treatment was applied, wherein the opposing substrate was a glass substrate having no electrode formed thereon but having a columnar spacer having a height of 4 μm.

[0257] The above two substrates are a set, and a sealant is printed on one of them, and the other is bonded in a manner that it faces the liquid crystal alignment film and the alignment direction is 0°, and then the sealant is hardened to obtain an empty cell. This empty cell is injected with liquid crystal MLC-2041 (Merck) by a reduced pressure injection method, and the injection port is sealed to obtain the liquid crystal display component of Example 1. The obtained liquid crystal display component is evaluated in the following evaluation method, and the results are shown in Table 3, wherein the detection method of the contrast variation within the pixel will be described later.

[0258] Examples 2 to 28 and Comparative Examples 1 to 6

[0259] Examples 2 to 28 and Comparative Examples 1 to 6 use the same preparation method for the liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display component as Example 1. The difference is that Examples 2 to 28 and Comparative Examples 1 to 6 change the type and usage of raw materials in the liquid crystal alignment agent. Their formulas and evaluation results are shown in Table 3, which will not be further described here.

[0260] Evaluation method

[0261] Intra-pixel contrast variation

[0262] The torsion angle variation of the liquid crystal display component was measured using an AxoStep device manufactured by AXOMETRICS. The liquid crystal display components prepared in the above-mentioned embodiments and comparative examples were placed on a measuring table, and the distribution of circular retardance in the pixel was measured without applying voltage, and the 3 times value (3σ) of the standard deviation (σ) was calculated. The smaller the 3 times value (3σ) of the standard deviation, the lower the contrast variation in the pixel, and the contrast variation in the pixel was evaluated according to the following criteria.

[0263] ※:3σ≦2.

[0264] ◎:2<3σ≦3.

[0265] ○: 3<3σ≦4.

[0266] △: 4<3σ≦5.

[0267] ╳:3σ>5.

[0268]

[0269] From the results in Table 3, it can be seen that if the diamine component (a2) of the liquid crystal alignment agent of the present invention does not contain the diamine compound (a2-1) shown in formula (A21), the liquid crystal display device containing the liquid crystal alignment film prepared using the liquid crystal alignment agent will have a higher intra-pixel contrast variation. 11 When Y in formula (A21) represents an aliphatic chain hydrocarbon group having 1 to 5 carbon atoms, the resulting liquid crystal display device will have a lower intra-pixel contrast variability. 11When represents a saturated straight-chain hydrocarbon group having a carbon number of 1 to 3, the obtained liquid crystal display device will have a lower contrast variation within the pixel. Furthermore, when the diamine component (a2) comprises a diamine compound (a2-2) as shown in formula (A22), the obtained liquid crystal alignment agent will make the formed liquid crystal display device have a lower contrast variation within the pixel. When the tetracarboxylic acid derivative component (a1) comprises an alicyclic tetracarboxylic dianhydride compound (a1-1) as shown in formula (A11), and X1 of formula (A11) represents a structure as shown in formula (A11-1-1), the liquid crystal display unit containing the liquid crystal alignment film formed therefrom has a lower contrast variation within the pixel.

[0270] It should be added that, although the present invention uses specific compounds, compositions, reaction conditions, processes, analysis methods or specific instruments as examples to illustrate the liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display component of the present invention, anyone with common knowledge in the technical field to which the present invention belongs can know that the present invention is not limited thereto. Without departing from the spirit and scope of the present invention, the liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display component of the present invention may also use other compounds, compositions, reaction conditions, processes, analysis methods or instruments.

[0271] Although the present invention has been disclosed as above in the form of an implementation method, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field to which the present invention belongs can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims

1. A liquid crystal alignment agent, characterized in that: Include: The polymer (A) is at least one selected from the group consisting of a polyimide precursor obtained by reacting a tetracarboxylic acid derivative component (a1) and a diamine component (a2), and an imide compound of the polyimide precursor, wherein the diamine component (a2) comprises a diamine compound (a2-1) represented by the following formula (A21): In formula (A21), Y 11 represents a hydrocarbon group having 1 to 10 carbon atoms; and n and m each independently represent 0 to 3.

2. The liquid crystal alignment agent according to claim 1, characterized in that: Y 11 represents an aliphatic chain hydrocarbon group having 1 to 5 carbon atoms.

3. The liquid crystal alignment agent according to claim 1, characterized in that: Y 11 represents a saturated straight-chain hydrocarbon group having 1 to 3 carbon atoms.

4. The liquid crystal alignment agent according to claim 1, characterized in that: The diamine component (a2) comprises a diamine compound (a2-2) represented by the following formula (A22): H2N-R1-R4-R2-R6-R5-R7-R3-NH2 (A22) In formula (A22), R1, R2 and R3 each independently represent a divalent organic group of a benzene ring or a pyridine ring; R4 represents an oxygen atom or a sulfur atom; R5 represents a divalent chain hydrocarbon group having 1 to 30 carbon atoms or an alicyclic hydrocarbon group having 3 to 30 carbon atoms; R6 and R7 each independently represent a single bond, an oxygen atom, a sulfur atom or -NR8-, wherein at least one of R6 and R7 represents an oxygen atom, a sulfur atom or -NR8-, and R8 represents a hydrogen atom or a methyl group; when any one of R1, R2 and R3 is a pyridine ring, R6 and R7 do not represent a single bond.

5. The liquid crystal alignment agent according to claim 1, characterized in that: The tetracarboxylic acid derivative component (a1) comprises an alicyclic tetracarboxylic dianhydride compound or a derivative thereof as shown in the following formula.

6. The liquid crystal alignment agent according to claim 1, characterized in that: Also includes: The polymer (B) is at least one selected from the group consisting of a polyimide precursor and an imidized polymer of the polyimide precursor, wherein the polymer (B) does not include a structure derived from the diamine compound (a2-1) represented by formula (A21).

7. The liquid crystal alignment agent according to any one of claims 1 to 6, characterized in that: The liquid crystal alignment agent is configured to prepare a liquid crystal alignment film used in a photo-alignment treatment method.

8. A liquid crystal alignment film, characterized in that: The liquid crystal alignment agent is formed by using the liquid crystal alignment agent as claimed in any one of claims 1 to 7.

9. A liquid crystal display component, characterized in that: It comprises the liquid crystal alignment film as claimed in claim 8.

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