Composition for forming liquid crystal alignment film

Abstract

A composition for forming a liquid crystal alignment film includes a photo-alignment polymer material for forming a liquid crystal alignment film, the photo-alignment polymer material having a side chain including a photo-alignment group, and a solvent mixture. The solvent mixture comprises (i) 45 to 70 wt% of at least one of an N-alkylpyrrolidone and a lactone, (ii) 5 to 15 wt% of a diethylene glycol dialkyl ether, and (iii) an ethylene glycol monoalkyl ether in an amount such that the total amount of the solvent mixture is 100 wt%. The composition has a solid content of 3.0 to 6.0 wt%. The composition can improve the coating performance while also increasing the film thickness near the printed film boundary without reducing the uniformity of the film.

Description

[0001] The present invention relates to a composition for forming a liquid crystal alignment film, a method for forming a liquid crystal alignment film, a liquid crystal alignment film, and a structured or unstructured optical and electro-optical element and device including the liquid crystal alignment film.

[0002] A liquid crystal device provides a display by controlling the alignment direction of liquid crystal molecules contained in a liquid crystal layer by applying a voltage to an electrode provided on a side surface of the liquid crystal layer of a substrate. A liquid crystal display device generally includes a liquid crystal alignment film for controlling the alignment direction of liquid crystal molecules, and the alignment film is provided on a side surface of the substrate on the liquid crystal layer side.

[0003] As a material for the alignment film constituting a liquid crystal display device, resins such as polyamic acid, polyimide, polyamide, polysiloxane, polymaleimide, polyacrylate, etc. are generally used. For example, it has been found that an alignment film containing polyimide exhibits excellent physical properties such as heat resistance, compatibility with liquid crystal, and mechanical strength.

[0004] Methods for printing an alignment film include spin coating, roll coating, flexographic printing, and inkjet printing. Inkjet printing is suitable for printing films on large substrates with high productivity.

[0005] However, inkjet printing is limited because the optimal range of the physical properties of the ink is very narrow. For example, the optimal range of surface tension is 28 - 40 mN / m, the optimal range of viscosity is 5 - 12 mPa·s, and the optimal range of the boiling point of the solvent is about 180 - 210 °C. Although a large number of solvents and their combinations are available for selection, it is by no means easy to optimize the components and component ratios of the ink so that the ink can meet various sometimes conflicting requirements.

[0006] When forming an alignment film into a panel, process defects during the alignment layer coating process will appear as defects in the panel display quality of the display surface. These defects are called "Mura" (meaning "flaw" in Japanese). Mura is a large-area pattern of inconsistent brightness on the display screen. Since a conventional inkjet printer for inkjet printing has a plurality of nozzles arranged perpendicular to the printing direction, if the ink dries before leveling, stripe-like irregularities in the film thickness will occur, resulting in uneven display. Therefore, in order to improve the leveling behavior of the ink, a low surface tension, low boiling point solvent (such as alcohol, ketone, or ester) is usually added to the ink to increase the wetting and diffusion properties of the ink.

[0007] Although the wetting and diffusion of the ink can improve the film uniformity of the alignment layer, excessive diffusion may cause a defect called "Frame Mura". This is related to the weakening of the alignment effect near the edge of the printed film. The reason for this phenomenon is that the film thickness of the alignment film decreases near the edge of the printed film, and the decrease in film thickness is due to the ink diffusing outside the printed area.

[0008] Therefore, it is necessary to further improve the coating performance of the ink, especially the diffusion (spreading) performance, in order to increase the film thickness near the edge of the printed film without reducing the film layer uniformity.

[0009] JP2006-017982A describes a liquid crystal aligning agent for inkjet applications, which contains a polymer having at least one of an amic acid repeating unit and its imidized repeating unit, and N-methylpyrrolidone.

[0010] CN102031122B describes a liquid crystal aligning agent, and Comparative Example 2 thereof shows a solvent composition containing NMP, butyl cellosolve, γ-butyrolactone, and diethylene glycol ethyl methyl ether.

[0011] EP2375278A1 describes a composition for forming a liquid crystal alignment film, wherein the composition contains a material for forming a liquid crystal alignment film, 4,6-dimethyl-2-heptanone, diisobutyl ketone, and at least one of γ-butyrolactone and N-methyl-2-pyrrolidone.

[0012] The present inventors have found that the above object can be achieved by selecting a specific solvent mixture suitable for inkjet printing.

[0013] Therefore, the present invention relates to a composition for forming a liquid crystal alignment film, which comprises:

[0014] - a photo-alignment polymer material for forming a liquid crystal alignment film, which has a side chain containing a photo-alignment group; and

[0015] - a solvent mixture, relative to the weight of the solvent mixture, the solvent mixture contains (i) at least one of N-alkylpyrrolidone and lactone in a total amount of 45-70 wt%, (ii) 5-15 wt% of diethylene glycol dialkyl ether, and (iii) ethylene glycol monoalkyl ether in an amount such that the solvent mixture is 100 wt%;

[0016] wherein the composition has a solid content of 3.0-6.0 wt%.

[0017] The solvent mixture contains (i) at least one of N-alkylpyrrolidone and lactone, (ii) ethylene glycol monoalkyl ether, and (iii) diethylene glycol dialkyl ether.

[0018] In N-alkylpyrrolidone, the alkyl part can be straight-chain or branched. Suitable N-alkylpyrrolidones include N-(C1-C8 alkyl)pyrrolidone, especially N-(C1-C4 alkyl)pyrrolidone, such as N-methylpyrrolidone, N-ethylpyrrolidone, and N-propylpyrrolidone. A particularly preferred N-alkylpyrrolidone is N-methyl-2-pyrrolidone.

[0019] Suitable lactones include α-lactones such as α-acetyl lactone, β-lactones such as β-propiolactone, γ-lactones such as γ-butyrolactone, and δ-lactones such as δ-valerolactone. Preferred are β-lactones, γ-lactones and δ-valerolactone, especially γ-lactones and δ-valerolactone. Particularly preferred lactone is γ-butyrolactone.

[0020] In ethylene glycol monoalkyl ethers, the alkyl moiety can be straight-chain or branched. Suitable ethylene glycol monoalkyl ethers (ethylene glycol ethers) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether and ethylene glycol monobutyl ether. Particularly preferred ethylene glycol monoalkyl ether is ethylene glycol monobutyl ether.

[0021] In diethylene glycol dialkyl ethers, the alkyl moiety can be straight-chain or branched. Suitable diethylene glycol dialkyl ethers include diethylene glycol dimethyl ether, diethylene glycol diethyl ether and diethylene glycol dibutyl ether. Particularly preferred diethylene glycol dialkyl ether is diethylene glycol diethyl ether.

[0022] In a preferred embodiment, the solvent mixture simultaneously contains N-alkylpyrrolidone and lactone. Preferably, relative to the weight of the solvent mixture, the solvent mixture contains 20-40 wt% of N-alkylpyrrolidone and 20-40 wt% of lactone, provided that the amounts of N-alkylpyrrolidone and lactone total 45-70 wt%.

[0023] In a more preferred embodiment, the solvent mixture comprises (i) at least one of N-alkylpyrrolidone and lactone, the total amount of which is 55-65 wt% of the weight of the solvent mixture; (ii) diethylene glycol dialkyl ether, the amount of which is 7-13 wt% of the weight of the solvent mixture; and (iii) ethylene glycol monoalkyl ether, the amount of which is such that the total amount of the solvent mixture is 100 wt%. Preferably, relative to the weight of the solvent mixture, the solvent mixture contains 25-35 wt% of N-alkylpyrrolidone and 25-35 wt% of lactone, provided that the amounts of N-alkylpyrrolidone and lactone total 55-65 wt%.

[0024] In one embodiment, the N-alkylpyrrolidone is N-methylpyrrolidone, the lactone is γ-butyrolactone, the ethylene glycol monoalkyl ether is ethylene glycol monobutyl ether, and the diethylene glycol dialkyl ether is diethylene glycol diethyl ether.

[0025] The composition has a solids content of 3.0-6.0 wt%, preferably 3.5-5.5 wt%, more preferably 3.5-5.0 wt%, and most preferably 3.7-4.7 wt%. The solids include a photo-orienting polymer material and an additional polymer material.

[0026] A photo - aligning polymer material is a photo - active polymer compound containing photo - aligning groups. It should be understood that the composition may contain more than one photo - aligning polymer material.

[0027] Suitable photo - aligning polymer materials are well - known in the field of liquid - crystal alignment materials. Such materials are used for preparing liquid - crystal alignment films for manufacturing optical and electro - optical devices and are disclosed in, for example, the following publications: O. Yaroshuk, Y. Renikov, J. Mater, Chem., 2012, 22, 286 - 300 and the references cited therein; US5,389,698; US5,838,407; US5,602,661; US6,160,597; US6,369,869; US6,717,644; US6,215,539; US6,300,991 and US6,608,661.

[0028] Under the irradiation of alignment light, especially polarized light, the photo - aligning groups undergo photoreactions such as photocrosslinking reaction, dimerization reaction, cis / trans isomerization reaction, rearrangement reaction, and degradation reaction. As a result, anisotropy is induced in the photo - aligning layer. The liquid crystal contained in the layer formed on the alignment film can be aligned under the influence of this photo - induced alignment film.

[0029] The photo - aligning polymer material containing photo - aligning groups is a polymer including copolymers, which has a side chain containing at least one photo - aligning group. Preferably, in addition to the photo - aligning group, the side chain further contains one or more aromatic or alicyclic groups.

[0030] In one embodiment, the photo - aligning groups are selected from cinnamate and chalcone, coumarin and quinoline, stilbene and cyanostilbene, azo group, chromone and chromene, mono - ethynyl and di - ethynyl groups (such as diphenylacetylene group), benzylidene phthalimide group, benzylidene acetophenone group, and / or benzodipropenoyl group. The photo - aligning groups may be optionally substituted. The photo - aligning material may contain one or more photo - aligning groups.

[0031] Preferably, the photo - aligning groups are selected from cinnamate and chalcone, coumarin, stilbene, and azo group. In a particularly preferred embodiment, the photo - aligning group is cinnamate.

[0032] Suitable photo - aligning groups are represented by the following formulas (I) to (VI). The photo - aligning groups are connected to one end of the polymer backbone (marked with an asterisk * in the general formula) through a single bond, a linking group, or a spacer group (discussed further below). The distal end bears a monovalent residue.

[0033]

[0034] The term "subst." represents an optional substituent as described below.

[0035] Formula (I) represents an α,β-unsaturated carbonyl group exemplified by a cinnamate group, wherein X is -O-, -S- or -NR a -, and R a is hydrogen or a C1-C6 alkyl group.

[0036] Formula (II) represents a chalcone group.

[0037] Formula (III) represents an azo group.

[0038] Formula (IV) represents a stilbene group, wherein Y is hydrogen, nitrile (cyano group, CN) or other electron-withdrawing groups.

[0039] Formula (V) represents a coumarin group.

[0040] Formula (VI) represents an α,β-unsaturated nitrile group.

[0041] The photo-orienting group can be connected to the polymer backbone via a single bond, a linking group (such as an ester group, a thioester group, an ether group, a carbonate group, an amide group or a sulfide group) or a spacer group. Preferably, the photo-orienting group is connected to the polymer backbone via a spacer group. The term "spacer group" should be understood as an optionally substituted aromatic or heteroaromatic group having 6-40 carbon atoms, or preferably a cyclic, straight-chain or branched, optionally substituted C1-C24-alkylene group, wherein one or more non-adjacent -CH2- groups can be independently replaced by groups selected from -O-, -CO-, -CO-O-, -O-CO, -NR b -, -NR b -CO-, -CO-NR b -, -NR b -CO-O-, -O-CO-NR b -, -NR b -CO-NR b -, -CH=CH-, -C≡C-, -O-CO-O- and -(CH3)2Si-O-Si(CH3)2-, wherein R b represents a hydrogen atom or a C1-C6-alkyl group.

[0042] The photo-orienting group can be optionally substituted. Suitable substituents include halogens such as fluorine, chlorine and bromine; cyano group; C1-C4-alkoxy groups; carboxyl groups; having a straight-chain or branched C1-C 12ester groups of an alkyl group, optionally substituted with fluorine or cyano groups; linear or branched alkyl and cycloalkyl groups having 1 - 12 carbon atoms, optionally substituted with fluorine or cyano groups; and / or aromatic groups having 6 - 18 carbon atoms, optionally substituted with the above groups. In a preferred embodiment, the side chain contains one or more fluorine atoms.

[0043] The main chain of the photo - aligning polymer material is not particularly limited and may be selected from polyamic acid, polyimide, polyamide, polysiloxane, polymaleimide, and polyacrylate. However, particularly preferred photo - aligning polymer materials are polysiloxane and polyamic acid polymers, preferably homopolymers and copolymers, more preferably copolymers. Polyamic acid polymers can be converted to polyimide by heat treatment. Subsequently, it has been found that polyimide and polysiloxane have excellent physical properties, such as heat resistance, compatibility with liquid crystals, and mechanical strength.

[0044] Thus, in one embodiment, the photo - aligning polymer material for forming liquid crystal alignment contains a repeating unit of the following formula (1):

[0045]

[0046] where Q is the tetravalent residue of a tetracarboxylic dianhydride, and P is the divalent residue of a diamine, where at least a part of P bears a side chain containing a photo - aligning group.

[0047] The tetravalent residue Q is understood to be equal to the tetracarboxylic acid (the tetracarboxylic acid used to form the tetracarboxylic dianhydride) minus the residue of four carboxyl groups.

[0048] The divalent residue P is understood to be equal to the diamine minus the residue of two amino groups. At least a part of P bears a side chain containing a photo - aligning group.

[0049] Preferably, the photo - aligning group is selected from cinnamate of formula (I), azo group of formula (III), coumarin of formula (V), and stilbene of formula (IV), which may be optionally substituted. In one embodiment, P contains 1 or 2 cinnamate groups of formula (I), and each cinnamate group independently contains at most three substituents "subst.".

[0050] In a preferred embodiment, in addition to the photo - aligning group, the side chain further contains one or more aromatic or alicyclic groups. Suitable aromatic groups are phenylene. Suitable alicyclic groups include cyclohexyl, dicyclohexyl, and tricyclohexyl.

[0051] The photo - aligning polymer material containing the repeating unit shown in formula (I) is generally obtained by polymerizing at least one diamine with an acid dianhydride, where at least a part of the diamine has at least one photo - aligning group.

[0052] The diamine is preferably selected from optionally substituted compounds of the following general formula:

[0053]

[0054]

[0055] wherein the residue P A contains a photo-orienting group, preferably a photo-orienting group represented by one of formulas (I) to (VI), more preferably represented by formula (I), and wherein the optional substituent is methyl, ethyl, halogen or methoxy.

[0056] In one embodiment, the residue PA is represented by the following formula:

[0057]

[0058] wherein:

[0059] A represents an optionally substituted aromatic or heteroaromatic ring having five or six atoms; preferably an optionally substituted phenylene;

[0060] B independently of one another represents an optionally substituted aromatic group, heteroaromatic group or alicyclic group selected from: a monocyclic ring having five or six ring atoms, a bicyclic system having eight, nine or ten ring atoms, a tricyclic system having thirteen or fourteen ring atoms, a fused ring system having eight to twenty ring atoms, or a bridged ring system having eight to twenty ring atoms and a bridging group selected from -O-, -CO-, -CO-O-, -O-CO-, -NR'-, -NR'-CO-, -CO-NR'-, -NR'-CO-O-, -O-CO-NR'-, -NR'-CO-NR'-, -CH=CH-, -C≡C-, -O-CO-O- and -(CH3)2Si-O-Si(CH3)2-, wherein R' represents a hydrogen atom or a C1-C6 alkyl group;

[0061] Z 1 and Z 2 independently of one another represent a bridging group selected from -O-, -CO-, -CO-O-, -O-CO-, -NR'-, -NR'-CO-, -CO-NR'-, -NR'-CO-O-, -O-CO-NR'-, -NR'-CO-NR'-, -CH=CH-, -C≡C-, -O-CO-O- and -(CH3)2Si-O-Si(CH3)2-, wherein R' represents a hydrogen atom or a C1-C6 alkyl group;

[0062] R 1 and R 2 are independently of one another hydrogen, halogen or nitrile;

[0063] R3 represents an optionally substituted C1-C 30 -alkyl or O-C1-C 30 -alkyl, which may be substituted by at least one of halogen or nitrile, preferably substituted by fluorine,

[0064] m is an integer between 0 and 4, preferably 1 or 2,

[0065] n is an integer between 0 and 6, preferably 1 or 2, more preferably 2; and

[0066] o is an integer between 0 and 2, preferably 0 or 1, more preferably 0.

[0067] In a preferred embodiment, B independently of one another represents an optionally substituted aromatic group or alicyclic group selected from: a monocyclic ring of five or six ring atoms, a bicyclic system of eight, nine or ten ring atoms, or a tricyclic system of thirteen or fourteen ring atoms. More preferably, B independently of one another represents an optionally substituted phenylene, cyclohexyl, dicyclohexyl or tricyclohexyl, in particular an optionally substituted phenylene, cyclohexyl or dicyclohexyl.

[0068] Preferably, Z 1 and Z 2 are selected from -O- and -O-CO-. More preferably, Z 1 is -O-CO-.

[0069] In a preferred embodiment, R 1 and R 2 are independently of one another hydrogen, nitrile or fluorine. More preferably, R 1 and R 2 are hydrogen.

[0070] Preferably, R 3 represents an optionally substituted C1-C6 alkyl, wherein the substituent is selected from nitrile and halogen, preferably fluorine, and preferably the substituent is preferably in the terminal position. In a preferred embodiment, R 3 is selected from C1-C6 alkyl and fluorinated C1-C6 alkyl, in particular from unsubstituted C2-C6 alkyl and C2-C6 alkyl containing a terminal trifluoromethyl moiety.

[0071] In a preferred embodiment, the residue P A is selected from:

[0072]

[0073]

[0074] The tetravalent organic residue Q of the tetracarboxylic dianhydride can be derived from an aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, or an aromatic tetracarboxylic dianhydride. Preferably, the tetravalent organic residue Q of the tetracarboxylic dianhydride is derived from an alicyclic tetracarboxylic dianhydride.

[0075] Suitable tetracarboxylic dianhydrides are well-known in the field of liquid crystal alignment materials and are used as monomers or comonomers to prepare liquid crystal alignment films for rubbing or photo-alignment techniques. Suitable dianhydrides include the dianhydrides of formula (VII):

[0076]

[0077] Examples of suitable aliphatic or alicyclic tetracarboxylic dianhydrides include:

[0078] 4,9-Dioxatricyclo[5.3.0.02,6]decane-3,5,8,10-tetrone,

[0079] 4,10-Dioxatricyclo[6.3.1.02,7]dodecane-3,5,9,11-tetrone,

[0080] 2,3,5-Tricarboxy-cyclopentylacetic acid-1,2:3,4-dianhydride (all isomers),

[0081] 1,2,3,4-Cyclobutanetetracarboxylic dianhydride,

[0082] 1,3-Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride,

[0083] 1,3-Dimethyl-1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride,

[0084] 1,2,3,4-Tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride,

[0085] 1,2,3,4-Cyclopentanetetracarboxylic dianhydride,

[0086] 2,3,5-Tricarboxycyclopentylacetic dianhydride,

[0087] 3,5,6-Tricarboxynorbornane-2-acetic dianhydride,

[0088] 2,3,4,5-Tetrahydrofurantetracarboxylic dianhydride,

[0089] 5-(2,5-Dioxotetrahydro-3-furanyl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione,

[0090] 5-(2,5-Dioxotetrahydro-3-furanyl)-5-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione,

[0091] 5-(2,5-Dioxotetrahydro-3-furanyl)-5-ethyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione,

[0092] 5-(2,5-Dioxotetrahydro-3-furanyl)-7-methyl-3a,4,5,7a-tetrahydro-2-benzofuran-1,3-dione,

[0093] 5-(2,5-Dioxotetrahydro-3-furanyl)-7-ethyl-3a,4,5,7a-tetrahydro-2-benzofuran-1,3-dione,

[0094] 5-(2,5-Dioxotetrahydro-3-furanyl)-6-methylhexahydro-2-benzofuran-1,3-dione,

[0095] 6-(2,5-Dioxotetrahydro-3-furanyl)-4-methylhexahydro-2-benzofuran-1,3-dione,

[0096] 5-(2,5-Dioxotetrahydrofuran)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride,

[0097] Bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic anhydride,

[0098] Bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic anhydride,

[0099] 1,8-Dimethylbicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic anhydride,

[0100] Tetrahydro-4,8-methano-furo[3,4-d]oxa -1,3,5,7-tetrone,

[0101] 3-(Carboxymethyl)-1,2,4-cyclopentanetricarboxylic 1,4:2,3-dianhydride,

[0102] Hexahydrofuro[3',4':4,5]cyclopenta[1,2-c]pyran-1,3,4,6-tetrone,

[0103] rel-[1S,5R,6R]-3-Oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione),

[0104] 4-(2,5-Dioxotetrahydrofuran-3-yl)tetralin-1,2-dicarboxylic anhydride,

[0105] 5-(2,5-Dioxotetrahydro-furan-3-yl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride,

[0106] 4-tert-Butyl-6-(2,5-dioxotetrahydro-3-furanyl)-2-benzofuran-1,3-dione,

[0107] 9-Isopropyl octahydro-4,8-methano-furo[3',4':3,4]cyclobuta[1,2-f][2]benzofuran-1,3,5,7-tetrone,

[0108] 1,2,5,6-Cyclooctanetetracarboxylic dianhydride,

[0109] Octahydro-4,8-methano-furo[3',4':3,4]cyclobuta[1,2-f][2]benzofuran-1,3,5,7-tetrone,

[0110] Octahydro-furo[3',4':3,4]cyclobuta[1,2-f][2]benzofuran-1,3,5,7-tetrone,

[0111] Tetrahydro-3,3'-bifuran-2,2',5,5'-tetrone, and

[0112] Tetrahydro-5,9-methano-1H-pyrano[3,4-d]oxa -1,3,6,8(4H)-tetrone.

[0113] Examples of suitable aromatic tetracarboxylic dianhydrides include:

[0114] Pyromellitic dianhydride,

[0115] 3,3',4,4'-Benzophenone tetracarboxylic dianhydride,

[0116] 4,4'-Oxydiphthalic dianhydride,

[0117] 3,3',4,4'-Diphenylsulfone tetracarboxylic dianhydride,

[0118] 1,4,5,8-Naphthalenetetracarboxylic dianhydride,

[0119] 2,3,6,7-Naphthalenetetracarboxylic dianhydride,

[0120] 3,3',4,4'-Dimethyldiphenylsilane tetracarboxylic dianhydride,

[0121] 3,3',4,4'-Tetraphenylsilane tetracarboxylic dianhydride,

[0122] 1,2,3,4-Furantetracarboxylic dianhydride,

[0123] 4,4'-Bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride,

[0124] 4,4'-Bis(3,4-dicarboxyphenoxy)diphenylsulfone dianhydride,

[0125] 4,4'-Bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride,

[0126] 3,3',4,4'-Biphenyltetracarboxylic dianhydride,

[0127] Ethylene glycol bis(trimesic) dianhydride,

[0128] 4,4'-(1,4-Phenylene)bis(phthalic) dianhydride,

[0129] 4,4'-(1,3-Phenylene)bis(phthalic) dianhydride,

[0130] 4,4'-(Hexafluoroisopropylidene)diphthalic dianhydride,

[0131] 4,4'-Oxydi(1,4-phenylene)bis(phthalic) dianhydride,

[0132] 4,4'-Methylenedi(1,4-phenylene)bis(phthalic) dianhydride, and

[0133] 4-tert-Butyl-6-(2,5-dioxotetrahydro-3-furanyl)-2-benzofuran-1,3-dione.

[0134] Particularly preferred examples of suitable tetracarboxylic dianhydrides include:

[0135] 4,9-Dioxatricyclo[5.3.0.02,6]decane-3,5,8,10-tetrone,

[0136] 4,10-Dioxatricyclo[6.3.1.02,7]dodecane-3,5,9,11-tetrone,

[0137] 1,2,3,4-Cyclobutanetetracarboxylic dianhydride,

[0138] 1,2,3,4-Cyclopentanetetracarboxylic dianhydride,

[0139] 2,3,5-Tricarboxycyclopentylacetic dianhydride,

[0140] Tetrahydro-4,8-methano-furo[3,4-d]oxa -1,3,5,7-tetrone,

[0141] 3-(Carboxymethyl)-1,2,4-cyclopentanetricarboxylic 1,4:2,3-dianhydride,

[0142] Hexahydrofuro[3',4':4,5]cyclopenta[1,2-c]pyran-1,3,4,6-tetrone,

[0143] 5-(2,5-dioxotetrahydrofuran-3-yl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride,

[0144] Pyromellitic dianhydride,

[0145] 4-(2,5-dioxotetrahydrofuran-3-yl)tetralin-1,2-dicarboxylic anhydride,

[0146] 5-(2,5-dioxotetrahydro-3-furanyl)-5-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione,

[0147] 5-(2,5-dioxotetrahydro-3-furanyl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione,

[0148] 5-(2,5-dioxotetrahydro-3-furanyl)-7-methyl-3a,4,5,7a-tetrahydro-2-benzofuran-1,3-dione,

[0149] 4-tert-butyl-6-(2,5-dioxotetrahydro-3-furanyl)-2-benzofuran-1,3-dione,

[0150] 4,4'-(hexafluoroisopropylidene)diphthalic anhydride,

[0151] Bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic anhydride, and

[0152] Tetrahydro-5,9-methano-1H-pyrano[3,4-d]oxa -1,3,6,8(4H)-tetrone.

[0153] Most preferably, the tetracarboxylic dianhydride is selected from 4,9-dioxatricyclo[5.3.0.02,6]decane-3,5,8,10-tetrone and 4,10-dioxatricyclo[6.3.1.02,7]dodecane-3,5,9,11-tetrone.

[0154] In one embodiment, the composition contains a polymer material (hereinafter referred to as "additional polymer material") in addition to the above-specified photoalignment polymer material.

[0155] In a preferred embodiment, the additional polymer material can be obtained by reacting a tetracarboxylic dianhydride and a diamine as described above. The diamine generally contains 6-40 carbon atoms. Suitable diamines include aliphatic diamines, alicyclic diamines, and / or diamines containing aryl groups. They can be used alone or in combination of two or more.

[0156] Suitable aliphatic diamines include compounds of formula (VIII):

[0157] H2N-alkylene-NH2 (VIII)

[0158] wherein the term "alkylene" refers to C1-C 24 alkylene, preferably C1-C 12 alkylene, which is branched, straight-chain, optionally substituted, optionally interrupted by a linking group as defined above, or an alicyclic group (such as cyclohexylene or C 17 -C 40 alicyclic group) or -Si(R c )2- or -O-Si(R c )2-, where R c represents hydrogen, fluorine, chlorine, nitrile, unsubstituted or fluorine-substituted C1-C 12 alkyl, in which one or more carbon atoms, -CH= or CH2- groups may be replaced by a linking group, preferably hydrogen, methyl or fluorine, more preferably hydrogen.

[0159] Suitable alicyclic diamines include compounds of formula (IX) and (X):

[0160]

[0161] where X 4 is a linking group as defined above (preferably -COO-, -CONH-), a single bond, -O-, -S-, methylene, ethylene, propylene, more preferably a single bond, or methylene, ethylene, propylene, butylene or pentylene optionally substituted by CF3, OCF3, F, and wherein cyclohexylene may be unsubstituted or independently substituted by hydrogen, halogen, hydroxy, a non-aromatic group of a carbocyclic or heterocyclic ring or C1-C 30 alkyl monosubstituted or polysubstituted, said C1-C 30 alkyl is branched, straight-chain, optionally substituted, optionally interrupted by a linking group as described above, more preferably interrupted by a non-aromatic group of a carbocyclic or heterocyclic ring such as cyclohexylene or C 17 -C 40 alicyclic group, more preferably said cyclohexylene may be independently substituted by halogen or optionally substituted methylene, ethylene or propylene.

[0162] Suitable aromatic diamines or diamines containing an optionally substituted aryl group include compounds selected from the following formula (XI):

[0163]

[0164] where X 5 is a single bond or C1-C 30An alkyl group, wherein C1-C 30 The alkyl group is preferably methyl, ethyl, propyl, butyl or pentyl;

[0165] Or a compound of formula (XII):

[0166]

[0167] Wherein X 6 Is a linking group as defined above, and preferably X 6 Is, for example, a single bond, -O-, -S- or optionally a straight-chain or branched C1-C6 alkylene group, -O-(CH2CH2O)n-, -O-(C1-C12 alkyl)n-O-, -S-(C1-C 12 Alkyl)n-S-, triazine, 1,3,5-triazinane-2,4,6-trione, 1,1'-cyclohexylene, NR 5 ((C1-C6 alkyl) n NR 6 )、-(piperidine) n1 -(C1-C6 alkyl) n -(piperidine) n , wherein n is an integer from 1 to 6 and n1 is an integer from 0 to 6, preferably X 6 Is a single bond, a straight-chain or branched C1-C6 alkylene group or -O-; wherein R 5 And R 6 Each independently represents hydrogen or a C1-C6 alkyl group, preferably hydrogen; or

[0168] A compound of formula (XIII):

[0169]

[0170] Wherein X 7 And X 8 Are linking groups as defined above; or

[0171] A compound of formula (XIV):

[0172]

[0173] Wherein X 9 、X 10 And X 11 Are linking groups as defined above; or

[0174] A compound of formula (XV):

[0175]

[0176] Wherein X 5 Has the above meaning and X 17 Is CH2, O or NH; or

[0177] Compound of formula (XVI):

[0178]

[0179] wherein R 9 and R 10 are C1-C 30 alkyl, preferably methyl; R 20 is 2-methylheptane; y is 0 or 1; and X 17 , X 18 and X 19 are a single bond, a carbonyl group or NH.

[0180] In the compounds of formulae (XI), (XII), (XIII), (XIV), (XV) and (XVI), the aryl group (especially the phenylene ring) is optionally substituted by at least one of a halogen, a hydroxyl group, a non-aromatic group of a carbocyclic or heterocyclic ring, or a C1-C 30 alkyl or an O-C1-C 30 alkyl, wherein the C1-C 30 alkyl is preferably methyl, ethyl, propyl, butyl, pentyl or 2-methylheptane; alternatively, the aryl group (especially the phenylene ring) may be substituted by at least one of the following groups: hexyl, 1,1'-cyclohexyl, 4-(C1-C 30 alkyl)-cyclohexyl, 3,4”-bis[4'-(C1-C 30 alkyl)-1,1'-bis(cyclohexyl)-4-yl], 1,1'-bis(cyclohexyl)-4-yl, 2-pyridine, pyrrolidine-2,5-dione, which is optionally substituted by the following groups: CF3, OCF3, F, benzyl, pentyl, benzoate, 4-(phenoxycarbonyl), carboxylic acid, -SO3H, -PO3H or -OR 15 (wherein R 15 is C1-C 30 alkyl) or an optionally substituted benzyl.

[0181] Preferably a diamine comprising at least one optionally substituted aryl group.

[0182] Examples of aliphatic and alicyclic diamines include:

[0183] Trimethylenediamine,

[0184] Tetramethylenediamine,

[0185] Hexamethylenediamine,

[0186] Octamethylenediamine,

[0187] 1,4-Diaminocyclohexane,

[0188] 4,4'-Methylenebis(cyclohexylamine),

[0189] 4,4'-Methylenebis(2-methylcyclohexylamine),

[0190] Isophoronediamine,

[0191] Tetrahydrodicyclopentadiene diamine, and

[0192] 1,3 - Adamantanediamine.

[0193] Preferred examples of diamines containing aryl include:

[0194] 1,3 - Bis(aminomethyl)benzene,

[0195] 1,4 - Bis(aminomethyl)benzene,

[0196] m - Phenylenediamine,

[0197] p - Phenylenediamine,

[0198] 2 - Methylbenzene - 1,3 - diamine,

[0199] 1,5 - Diaminonaphthalene,

[0200] 4,4' - Diaminodiphenyl ether,

[0201] 3,4' - Diaminodiphenyl ether,

[0202] 4,4' - Diaminodiphenyl sulfide,

[0203] 4,4 - Diamino - 2,2' - dichlorodiphenyl disulfide,

[0204] 4,4' - Diaminodiphenyl sulfone,

[0205] 3,3' - Diaminodiphenyl sulfone,

[0206] 4,4' - Diaminodiphenyl methane,

[0207] 3,3' - Diaminodiphenyl methane,

[0208] 3,4' - Diaminodiphenyl methane,

[0209] 4,4' - Diamino - 2,2' - dimethylbiphenyl,

[0210] 4,4' - Diamino - 3,3' - dimethyldiphenyl methane,

[0211] 4,4' - Diaminodiphenyl ethane,

[0212] 3,3' - Diaminobenzophenone,

[0213] 4,4' - Diaminobenzophenone,

[0214] 3,4'-Diaminobenzophenone,

[0215] 2,2-Bis(4-aminophenyl)hexafluoropropane,

[0216] 2,2-Bis[4-(4-aminophenoxy)phenyl]hexafluoropropane,

[0217] 2,2-Bis[4-(4-aminophenoxy)phenyl]propane,

[0218] 1,4-Bis(4-aminophenoxy)benzene,

[0219] 1,3-Bis(4-aminophenoxy)benzene,

[0220] 4,4'-Diamino-diphenylene-cyclohexane,

[0221] 3,5-Diamino-3'-trifluoromethylbenzoylaniline,

[0222] 3,5-Diamino-4'-trifluoromethylbenzoylaniline,

[0223] 4,4'-Diaminobenzoylaniline,

[0224] 2-Amino-4-[1-(3-amino-4-hydroxyphenyl)-1-methylethyl]phenol,

[0225] Diaminofluorene derivatives, such as 2,7-diaminofluorene and 9,9-bis(4-aminophenyl)fluorene,

[0226] Diaminoanthraquinone derivatives, such as 1,5-diaminoanthraquinone,

[0227] Phenylenediamine derivatives, such as 4,4'-diaminobiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, tetramethylphenylenediamine, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl,

[0228] 5-Amino-1-(4'-aminophenyl)-1,3,3-trimethylindane,

[0229] 6-Amino-1-(4'-aminophenyl)-1,3,3-trimethylindane,

[0230] 4-(4-Amino-2-methylphenyl)-3-methylaniline,

[0231] 4-[4-Amino-2-(trifluoromethyl)phenyl]-3-(trifluoromethyl)aniline,

[0232] 4,4'-Methylene-bis(2-chloroaniline),

[0233] 4,4‘-(p-Phenylenediisopropylidene)dianiline,

[0234] 4,4‘-(m-Phenylenediisopropylidene)dianiline,

[0235] 2-(4-Aminophenyl)-1H-benzimidazol-5-amine,

[0236] Bis(4-aminophenoxy)-2,2-dimethylpropane, and

[0237] 1,5-Diaminonaphthalene, 2,7-diaminofluorene.

[0238] More preferred examples of the diamine containing an aryl group include:

[0239] m-Phenylenediamine,

[0240] p-Phenylenediamine,

[0241] 2-Methylbenzene-1,3-diamine,

[0242] 1,5-Diaminonaphthalene,

[0243] 4,4'-Diaminodiphenyl ether,

[0244] 3,4'-Diaminodiphenyl ether,

[0245] 4,4'-Diaminodiphenyl sulfide,

[0246] 4,4'-Diaminodiphenyl sulfone,

[0247] 4,4'-Diaminodiphenyl methane,

[0248] 4,4'-Diaminodiphenyl ethane,

[0249] 2,2-Bis(4-aminophenyl)hexafluoropropane,

[0250] 2,2-Bis[4-(4-aminophenoxy)phenyl]hexafluoropropane,

[0251] 2,2-Bis[4-(4-aminophenoxy)phenyl]propane,

[0252] 1,4-Bis(4-aminophenoxy)benzene,

[0253] 1,3-Bis(4-aminophenoxy)benzene,

[0254] 2,7-Diaminofluorene,

[0255] 4,4'-Diaminobiphenyl,

[0256] 4,4'-Diamino-3,3'-dimethylbiphenyl,

[0257] 4,4'-Diamino-2,2'-dimethylbiphenyl,

[0258] 4-(4-Amino-2-methyl-phenyl)-3-methyl-aniline,

[0259] 4-[4-Amino-2-(trifluoromethyl)phenyl]-3-(trifluoromethyl)aniline,

[0260] 4,4'-(p-Phenylenebis(isopropylidene))dianiline,

[0261] 4,4'-(m-Phenylenebis(isopropylidene))dianiline,

[0262] 2-(4-Aminophenyl)-1H-benzimidazol-5-amine,

[0263] Bis(4-aminophenoxy)-2,2-dimethylpropane, and

[0264] 2-Amino-4-[1-(3-amino-4-hydroxyphenyl)-1-methyl-ethyl]phenol.

[0265] Particularly preferred aryl-containing diamines include:

[0266] p-Phenylenediamine,

[0267] 2-Methylbenzene-1,3-diamine,

[0268] 4,4'-Diaminodiphenyl ether,

[0269] 3,4'-Diaminodiphenyl ether,

[0270] 4,4'-Diaminodiphenyl sulfide,

[0271] 4,4'-Diaminodiphenyl methane,

[0272] 4,4'-Diaminodiphenyl ethane,

[0273] 2,2-Bis[4-(4-aminophenoxy)phenyl]propane,

[0274] 1,4-Bis(4-aminophenoxy)benzene,

[0275] 1,3-Bis(4-aminophenoxy)benzene,

[0276] 4,4'-Diamino-3,3'-dimethylbiphenyl,

[0277] 4,4'-Diamino-2,2'-dimethylbiphenyl,

[0278] 4-(4-Amino-2-methyl-phenyl)-3-methyl-aniline,

[0279] 4-[4-Amino-2-(trifluoromethyl)phenyl]-3-(trifluoromethyl)aniline,

[0280] 4,4'-(p-Phenylenebis(isopropylidene))dianiline,

[0281] 4,4'-(m-Phenylenebis(isopropylidene))dianiline,

[0282] 2-(4-Aminophenyl)-1H-benzimidazol-5-amine,

[0283] Bis(4-aminophenoxy)-2,2-dimethylpropane, and

[0284] 2-Amino-4-[1-(3-amino-4-hydroxyphenyl)-1-methylethyl]phenol.

[0285] Even more preferably, the diamine containing an aryl group is:

[0286] 4,4'-Diaminodiphenyl ether,

[0287] 3,4'-Diaminodiphenyl ether,

[0288] 4,4'-Diamino-2,2'-dimethylbiphenyl,

[0289] 2-Amino-4-[1-(3-amino-4-hydroxyphenyl)-1-methylethyl]phenol.

[0290] In addition, the composition of the present invention may optionally contain one or more additives. They are generally used in small amounts to improve certain performance criteria of the composition of the present invention, such as coating and printing behavior, storage stability, and inhibition of color formation, and for example, to improve the mechanical, thermal, and photo-orientation properties of the alignment layer produced by the composition of the present invention.

[0291] Optional additives are generally classified into antioxidants, inhibitors, stabilizers, surface-active agents, flow improvers, defoamers, sensitizers, adhesion promoters, thixotropic agents, pigments, initiators, nucleating agents, clarifying agents, antistatic agents, slip agents, silica, talc, stabilizers, ultraviolet stabilizers, lubricants, coupling agents, antibacterial agents, crosslinking agents, surfactants, photoactive agents, photosensitizers, photo-generating agents, etc.

[0292] Additives such as silane-containing compounds and epoxy-containing crosslinking agents can be added. Suitable silane-containing additives are described in Plast. Eng. 36(1996), (Polyimides, fundamentals and applications), Marcel Dekker, Inc. Suitable epoxy-group-containing crosslinking additives include 4,4'-methylenebis(N,N-diglycidylaniline), trimethylolpropane triglycidyl ether, benzene-1,2,4,5-tetracarboxylic acid 1,2,4,5-N,N'-diglycidyl diimide, polyethylene glycol diglycidyl ether, N,N-diglycidyl cyclohexylamine, etc.

[0293] Other suitable additives include a mixture of 2,2-dimethoxyacetophenone, benzophenone and N,N-dimethylaniline or ethyl 4-(dimethylamino)benzoate, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, (a 1:1 weight ratio mixture of 1-hydroxy-cyclohexyl-phenyl-ketone and benzophenone), 2,2-dimethoxy-1,2-diphenylethan-1-one or Michler's ketone. Non-limiting examples include hydroquinone, 2,6-di-tert-butyl-4-methylphenol (BHT), 4-ethoxyphenol, 4-methoxyphenol, phenothiazine and N-phenyl-2-naphthylamine.

[0294] The amount of the additive in the composition is generally less than 20% of the total weight of the composition, preferably less than 10%, more preferably less than 5%, and even more preferably less than 2%.

[0295] The present invention also relates to a method for forming a liquid crystal alignment film, which includes:

[0296] - applying the composition of the present invention onto a substrate (substrate),

[0297] - drying the obtained wet film, and

[0298] - irradiating the dried film to impart liquid crystal alignment ability.

[0299] The substrate can be transparent or opaque, and is preferably selected from glass and plastic substrates, polymer films such as polyethylene terephthalate (PET), triacetyl cellulose (TAC), polypropylene, which are optionally coated with indium tin oxide (ITO). Specifically, the composition can be applied onto a support (such as a glass plate coated with indium tin oxide (ITO)) optionally coated with an electrode, so as to produce a uniform layer with a thickness of 0.050 - 50 μm, preferably 0.050 - 1.00 μm, more preferably 0.080 - 0.120 μm.

[0300] The composition can be applied to a substrate by general coating and printing methods known in the art. Coating methods include, for example, spin coating, blade coating, knife coating, reverse roll coating, transfer roll coating, gravure roll coating, contact roll coating, casting coating, spraying, slot orifice coating, calendering coating, electrodeposition coating, dip coating or die coating. Printing methods include letterpress printing (e.g., flexographic printing), inkjet printing, intaglio printing (e.g., direct gravure printing or offset gravure printing), lithographic printing (e.g., offset printing) or screen printing (e.g., silk screen printing). The preferred printing method is inkjet printing.

[0301] After applying the composition to the substrate, the wet film is dried and the area to be oriented is irradiated, for example, with a high-pressure mercury vapor lamp, a xenon lamp or a pulsed ultraviolet laser, using a polarizer and optionally a mask to create an image of the structure.

[0302] The method suitably includes a step of heat-treating the dried film at a temperature of 80 - 230 °C. When the photo-orienting polymer material is a polyamic acid polymer or copolymer, the heat-treatment step can convert most or all of the polyamic acid groups into polyimide groups. The polyimide film thus obtained has excellent physical properties such as heat resistance, compatibility with liquid crystals and mechanical strength.

[0303] In one embodiment, an orienting light is used. Preferably, the wavelength is in the range of UV-A, UVB and / or UV / C, or in the visible light range. This depends on which wavelengths the photo-orienting compound is suitable for. Preferably, the photo-orienting group is sensitive to visible light and / or ultraviolet light. The instantaneous direction of the aligning light can be perpendicular to the substrate or at any oblique angle to the substrate, but not including 0°. The irradiation with the orienting light can be carried out in a single step or in several separate steps. In a preferred embodiment of the present invention, the treatment with the orienting light is carried out in a single step.

[0304] More preferably, the orienting light is at least partially linearly polarized light, elliptically polarized light (e.g., circularly polarized light), or unpolarized light; most preferably at least circularly polarized light or partially linearly polarized light, or unpolarized light with oblique exposure. In particular, the most preferred orienting light represents substantially polarized light, especially linearly polarized light.

[0305] The direction of the polarized light is understood as the intersection line of the surface of the alignment layer and the polarization plane of the polarized light during exposure. If the polarized light is elliptically polarized, the polarization plane refers to the plane determined by the incident direction of the light and the major axis of the polarization ellipse.

[0306] The term "direction of polarized light" used in the present invention is not only used to describe the direction of the polarized light during the exposure process, but also refers to the direction of the polarized light applied to the alignment layer during exposure after the exposure is completed.

[0307] The irradiation time depends on the output of each lamp and can vary from a few seconds to several hours. For the irradiation of the uniform layer, a filter can also be used, which, for example, only allows certain wavelengths to pass through, for example, wavelengths suitable for inducing a crosslinking reaction.

[0308] The present invention also relates to a liquid crystal alignment film obtained by the method of the present invention.

[0309] The present invention also relates to structured or unstructured optical and electro-optical elements and devices comprising a liquid crystal alignment film obtained by the method of the present invention. Examples of structured or unstructured optical and electro-optical elements and devices include optical films, retarders, liquid crystal displays (LCDs), organic field effect transistors (OFETs), organic light emitting diodes (OLEDs), smart windows, and sensors.

[0310] The present invention is described in more detail by the following examples.

[0311] The following abbreviations are used.

[0312] 1 H NMR: 1 H nuclear magnetic resonance spectrum, m: multiplet, d: doublet, dd: double doublet, t: triplet, s: singlet, b: broad peak

[0313] DMSO-d6: deuterated dimethyl sulfoxide

[0314] MS: mass spectrometry

[0315] ITO: indium tin oxide

[0316] IBIB: isobutyl isobutyrate

[0317] PTFE: polytetrafluoroethylene

[0318] MeOH: methanol

[0319] DMF: N,N-dimethylformamide

[0320] NMP: N-methyl-2-pyrrolidone

[0321] BL or GBL: γ-butyrolactone

[0322] DEE: diethylene glycol diethyl ether

[0323] EEP: ethyl 3-ethoxypropionate

[0324] BC: ethylene glycol monobutyl ether (ButylCELLOSOLVE TM )

[0325] MIBK: methyl isobutyl ketone

[0326] 4,9-Dioxatricyclo[5.3.0.02,6]decane-3,5,8,10-tetrone refers to the compound with the CAS number 4415-87-6.

[0327] 4,10-Dioxatricyclo[6.3.1.02,7]dodecane-3,5,9,11-tetrone refers to the compound with the CAS number 6053-46-9.

[0328] 4-(4-Aminophenoxy)aniline refers to the compound with the CAS number 101-80-4.

[0329] (Trans, trans)-4'-(4,4,4-Trifluorobutyl)[1,1'-bicyclohexyl]-4-carboxylic acid refers to the compound with the CAS number 1887749-09-8

[0330] Method

[0331] As described in detail below, different compositions for forming a liquid crystal alignment film are prepared and examined using the following method. The ink is printed on a 0.7 mm Kuramato polished sodium glass / SiO2 (20 nm) / ITO (160 nm) substrate using an LP50 Suss Micro Tec inkjet printer, and the setting parameters are adjusted so that the coating thickness in the middle of the printing area reaches 107 nm. The heat treatment is carried out at 25 °C for 50 seconds, then at 100 °C for 90 seconds on a hot plate with spacer pins (6 mm high), and finally at 200 °C for 10 minutes on a hot plate without pins.

[0332] A. Viscosity

[0333] The viscosity is measured at 25 °C using a Brookfield DV-ll+pro viscometer.

[0334] B. Surface tension

[0335] The surface tension is measured at 20 °C using a Kibron AquaPi microtensiometer.

[0336] C. Diffusion (spreading)

[0337] The diffusion is determined by measuring the final size of the printed area after heat treatment along the lateral scan direction (perpendicular to the printing direction) with a ruler. Subtract the printing width (40 mm), and then divide the result by 2 to obtain the diffusion value in mm.

[0338] D. Minimum thickness of the boundary region

[0339] Use an Alpha- -100 profilometer (KLA-Tencor) to measure the minimum thickness of the boundary region.

[0340] Preparation of monomer

[0341] Preparation of (E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoic acid

[0342] 19.5 g (164.1 mmol) of thionyl chloride was gradually added to a suspension of 37.0 g (149.1 mmol) of 4-(4,4,4-trifluorobutoxy)benzoic acid in 100 mL of toluene and 0.8 mL of DMF over a period of 30 minutes at 70 °C. After maintaining at 75 °C for 2 hours, the excess thionyl chloride was distilled off under reduced pressure. Subsequently, the reaction mixture was cooled to room temperature and 18.9 g (155.1 mmol) of 4-hydroxybenzaldehyde, 0.91 g (7.5 mmol) of 4-dimethylaminopyridine, and 52.0 g (657.4 mmol) of pyridine were added.

[0343] After stirring at room temperature for 2 hours, 26.53 g (254.9 mmol) of malonic acid and 7.3 g (102.6 mmol) of pyrrolidine were added and the reaction mixture was heated to 80 °C. After maintaining at 80 °C for 4 hours, the reaction mixture was cooled to 40 °C, 150 mL of MeOH was added and the reaction mixture was cooled to 0 °C. After maintaining at 0 °C for 1 hour, the precipitate was filtered off, washed with 100 mL of cold methanol and dried in vacuo at 40 °C to give 53.0 g (90%) of (E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoic acid as a white powder.

[0344] 1 H NMR (300 MHz), in DMSO-D6: 12.40 (b, 1H), 8.08 (d, 2H), 7.79 (d, 2H), 7.63 (d, 1H), 7.32 (d, 2H), 7.14 (d, 2H), 6.54 (d, 1H), 4.17 (t, 2H), 2.45 (m, 2H), 1.98 (m, 2H).

[0345] Preparation of (E)-3-[4-(4-pentylcyclohexanecarbonyl)oxyphenyl]prop-2-enoic acid

[0346] 11.63 g (97.74 mmol) of thionyl chloride was gradually added to a suspension of 17.62 g (88.86 mmol) of 4-pentylcyclohexanecarboxylic acid in 75 mL of toluene and 0.06 mL of DMF over a 30-minute period at 75 °C. After maintaining at 75 °C for 2 hours, the excess thionyl chloride was distilled off under reduced pressure. Subsequently, the reaction mixture was cooled to room temperature and 11.29 g (92.41 mmol) of 4-hydroxybenzaldehyde, 0.54 g (4.44 mmol) of 4-dimethylaminopyridine, and 30.5 g (385.64 mmol) of pyridine were added.

[0347] After stirring at room temperature for 2 hours, 15.81 g (151.95 mmol) of malonic acid and 3.22 g (45.32 mmol) of pyrrolidine were added and the reaction mixture was heated to 80 °C. After maintaining at 80 °C for 4 hours, the reaction mixture was cooled to 40 °C, 150 mL of MeOH was added and the reaction mixture was cooled to 0 °C. After maintaining at 0 °C for 1 hour, the precipitate was filtered off, washed with 100 mL of cold methanol and dried in vacuo at 40 °C to give 24.5 g (80%) of (E)-3-[4-(4-pentylcyclohexanecarbonyl)oxyphenyl]prop-2-enoic acid as a white powder.

[0348] 1 1H NMR (300 MHz), in DMSO-D6: 12.37 (b, 1H), 7.73 (d, 2H), 7.59 (d, 1H), 7.14 (d, 2H), 6.50 (d, 1H), 2.50 (m, 1H), 2.08 (m, 2H), 1.80 (m, 2H), 1.5 - 0.7 (m, 13H), 0.85 (t, 3H).

[0349] Preparation of (E)-3-[4-[4-(4-pentylcyclohexyl)cyclohexanecarbonyl]oxyphenyl]prop-2-enoic acid

[0350] 11.63 g (97.74 mmol) of thionyl chloride was gradually added to a suspension of 24.92 g (88.86 mmol) of 4-(4-pentylcyclohexyl)cyclohexanecarboxylic acid in 75 mL of toluene and 0.06 mL of DMF over a 30-minute period at 75 °C. After maintaining at 75 °C for 2 hours, the excess thionyl chloride was distilled off under reduced pressure. Subsequently, the reaction mixture was cooled to room temperature and 11.29 g (92.41 mmol) of 4-hydroxybenzaldehyde, 0.54 g (4.44 mmol) of 4-dimethylaminopyridine, and 30.5 g (385.64 mmol) of pyridine were added.

[0351] After stirring at room temperature for 2 hours, 15.81 g (151.95 mmol) of malonic acid and 3.22 g (45.32 mmol) of pyrrolidine were added and the reaction mixture was heated to 80 °C. After maintaining at 80 °C for 4 hours, the reaction mixture was cooled to 40 °C, 150 mL of MeOH was added and the reaction mixture was cooled to 0 °C. After maintaining at 0 °C for 1 hour, the precipitate was filtered off, washed with 100 mL of cold methanol and dried in vacuo at 40 °C to give 31.54 g (83%) of (E)-3-[4-[4-(4-pentylcyclohexyl)cyclohexanecarbonyl]oxyphenyl]prop-2-enoic acid as a white powder.

[0352] 1 1H NMR (300 MHz), in DMSO-d6: 12.37 (b, 1H), 7.73 (d, 2H), 7.59 (d, 1H), 7.14 (d, 2H), 6.50 (d, 1H), 2.08 (m, 2H), 1.73 (m, 6H), 1.5 - 0.7 (m, 20H), 0.85 (t, 3H).

[0353] Preparation of (E)-3-[4-[4-[4-(4,4,4-trifluorobutyl)cyclohexyl]cyclohexanecarbonyl]oxyphenyl]prop-2-enoic acid

[0354] 2.82 g (23.69 mmol) of thionyl chloride was gradually added to a suspension of 6.90 g (21.54 mmol) of (trans,trans)-4′-(4,4,4-trifluorobutyl)[1,1′-bicyclohexyl]-4-carboxylic acid in 18 mL of toluene and 0.06 mL of DMF over a period of 30 minutes at 75 °C. After maintaining at 75 °C for 2 hours, the excess thionyl chloride was distilled off under reduced pressure. Subsequently, the reaction mixture was cooled to room temperature and 2.74 g (22.40 mmol) of 4-hydroxybenzaldehyde, 0.13 g (1.08 mmol) of 4-dimethylaminopyridine and 7.39 g (93.43 mmol) of pyridine were added.

[0355] After stirring at room temperature for 2 hours, 3.83 g (36.83 mmol) of malonic acid and 0.78 g (10.98 mmol) of pyrrolidine were added and the reaction mixture was heated to 80 °C. After maintaining at 80 °C for 4 hours, the reaction mixture was cooled to 40 °C, 150 mL of MeOH was added and the reaction mixture was cooled to 0 °C. After maintaining at 0 °C for 1 hour, the precipitate was filtered off and washed with 100 mL of cold methanol. The solid was suspended in a mixture of 18 mL of MeOH, 6 mL of water and 3 g of 25% HCl solution. After stirring for 2 hours, the solid was filtered off, washed with MeOH, water and heptane and dried at 40 °C for 48 hours to give 4.90 g (48.7%) of (E)-3-[4-[4-[4-(4,4,4-trifluorobutyl)cyclohexyl]cyclohexanecarbonyl]-oxyphenyl]prop-2-enoic acid as a white powder.

[0356] 1 1H NMR (300 MHz), in DMSO-D6: 12.38 (s, 1H), 7.73 (d, 2H), 7.59 (d, 1H), 7.14 (d, 2H), 6.50 (d, 1H), 2.91 (m, 1H), 2.3 (m, 3H), 1.73 - 0.7 (m, 22H).

[0357] Preparation of [4-[(E)-3-[2-(2,4-dinitrophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate

[0358] 2.50 g (11.8 mmol) of 2-(2,4-dinitrophenyl)ethanol, 4.65 g (11.8 mmol) of (E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoic acid and 144 mg (1.2 mmol) of 4-dimethylaminopyridine were dissolved in 30 mL of dichloromethane. 2.48 g (13.0 mmol) of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC hydrochloride) was added at 0 °C. The solution was stirred at 0 °C for 1 hour and then at room temperature overnight.

[0359] After 22 hours at room temperature, the reaction mixture was partitioned between dichloromethane and water. The organic phase was washed repeatedly with water, dried over sodium sulfate, filtered and concentrated by rotary evaporation. The residue was purified on silica gel using toluene:ethyl acetate (95:5) as the eluent. Crystallization from a mixture of ethyl acetate:hexane (1:1) gave 5.21 g (75%) of [4-[(E)-3-[2-(2,4-dinitrophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate as colorless crystals.

[0360] 1 1H NMR (300 MHz), in DMSO-D6: δ 8.74 (d, 1H), 8.51 (dd, 1H), 8.09 (dd, 2H), 7.93 (d, 1H), 7.80 (d, 2H), 7.65 (d, 1H), 7.34 (d, 2H), 7.14 (d, 2H), 6.55 (d, 1H), 4.47 (t, 2H), 4.17 (t, 2H), 2.45 (m, 2H), 2.00 (m, 2H).

[0361] Preparation of [4-[(E)-3-[2-(2,4-dinitrophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-pentylcyclohexanecarboxylate

[0362] 2.50 g (11.8 mmol) of 2-(2,4-dinitrophenyl)ethanol, 4.06 g (11.8 mmol) of (E)-3-[4-(4-pentylcyclohexanecarbonyl)oxyphenyl]acrylic acid and 144 mg (1.2 mmol) of 4-dimethylaminopyridine were dissolved in 30 mL of dichloromethane. 2.48 g (13.0 mmol) of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC hydrochloride) was added at 0 °C. The solution was stirred at 0 °C for 1 h and then at room temperature overnight.

[0363] After 22 h at room temperature, the reaction mixture was partitioned between dichloromethane and water. The organic phase was washed repeatedly with water, dried over sodium sulfate, filtered and concentrated by rotary evaporation. The residue was purified on silica gel using toluene:ethyl acetate (95:5) as the eluent. Crystallization from an ethyl acetate:hexane (1:1) mixture gave 4.44 g (70%) of [4-[(E)-3-[2-(2,4-dinitrophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-pentylcyclohexanecarboxylate as colorless crystals.

[0364] 1 1H NMR (300 MHz), in DMSO-D6: δ 8.73 (d, 1H), 8.51 (dd, 1H), 7.92 (d, 1H), 7.75 (d, 2H), 7.60 (d, 1H), 7.15 (d, 2H), 6.51 (d, 1H), 4.47 (t, 2H), 3.38 (t, 2H), 2.5 (m, 1H), 2.1 (m, 2H), 1.8 (m, 2H), 1.5 - 0.7 (m, 13H), 0.85 (t, 3H).

[0365] Preparation of [4-[(E)-3-[2-(2,4-dinitrophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4-pentylcyclohexyl)cyclohexanecarboxylate

[0366] 2.50 g (11.8 mmol) of 2-(2,4-dinitrophenyl)ethanol, 5.03 g (11.8 mmol) of (E)-3-[4-[4-(4-pentylcyclohexyl)cyclohexanecarbonyl]oxyphenyl]prop-2-enoic acid and 144 mg (1.2 mmol) of 4-dimethylaminopyridine were dissolved in 30 mL of dichloromethane. 2.48 g (13.0 mmol) of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC hydrochloride) was added at 0 °C. The solution was stirred at °C for 1 hour and then at room temperature overnight.

[0367] After 22 hours at room temperature, the reaction mixture was partitioned between dichloromethane and water. The organic phase was washed repeatedly with water, dried over sodium sulfate, filtered and concentrated by rotary evaporation. The residue was purified on silica gel using toluene:ethyl acetate (95:5) as the eluent. Crystallization from an ethyl acetate:hexane (1:1) mixture gave 5.49 g (75%) of [4-[(E)-3-[2-(2,4-dinitrophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4-pentylcyclohexyl)cyclohexanecarboxylate as colorless crystals.

[0368] 1 H NMR (300 MHz), in DMSO-D6: δ 8.74 (d, 1H), 8.51 (dd, 1H), 7.92 (d, 1H), 7.75 (d, 2H), 7.61 (d, 1H), 7.16 (d, 2H), 6.52 (d, 1H), 4.46 (t, 2H), 3.38 (t, 2H), 2.1 (m, 2H), 1.7 (m, 6H), 1.5 - 0.7 (m, 20H), 0.85 (t, 3H).

[0369] Preparation of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate

[0370] 4.93 g (8.38 mmol) of [4-[(E)-3-[2-(2,4-dinitrophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate was dissolved in a mixture of 54 mL of N,N-dimethylformamide and 6 mL of water. 13.9 g (51.4 mmol) of iron(III) chloride hexahydrate was added. 5.60 g (85.7 mmol) of zinc powder was gradually added over a period of 60 minutes. The mixture was reacted for 2 hours. The reaction mixture was then partitioned between ethyl acetate and water and filtered. The organic phase was washed repeatedly with water, dried over sodium sulfate, filtered and concentrated by rotary evaporation. The residue was filtered through silica gel using toluene:ethyl acetate (1:3) as eluent and crystallized from ethyl acetate:hexane (1:1) to give 3.20 g (72%) of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate as an orange powder.

[0371] 1 1H NMR (300 MHz), in DMSO-d6: δ 8.10 (d, 2H), 7.83 (d, 2H), 7.70 (d, 1H), 7.34 (d, 2H), 7.15 (d, 2H), 6.64 (m, 1H + 1H), 5.90 (m, 1H), 5.80 (m, 1H), 4.66 (m, 2H), 4.58 (m, 2H), 4.18 (m, 2H + 2H), 2.70 (t, 2H), 2.47 (m, 2H), 2.01 (m, 2H).

[0372] Preparation of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-pentylcyclohexanecarboxylate

[0373] 4.51 g (8.38 mmol) of [4-[(E)-3-[2-(2,4-dinitrophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-pentylcyclohexanecarboxylate was dissolved in a mixture of 54 mL of N,N-dimethylformamide and 6 mL of water. 13.9 g (51.4 mmol) of iron(III) chloride hexahydrate was added. 5.60 g (85.7 mmol) of zinc powder was gradually added over a period of 60 minutes. The mixture was reacted for 2 hours.

[0374] The reaction mixture was then partitioned between ethyl acetate and water and filtered. The organic phase was washed repeatedly with water, dried over sodium sulfate, filtered and concentrated by rotary evaporation. The residue was filtered through silica gel using toluene:ethyl acetate (1:3) as the eluent and crystallized from ethyl acetate:hexane (1:1) to give 2.88 g (72%) of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-pentylcyclohexanecarboxylate as a yellow powder.

[0375] 1 1H NMR (300 MHz), in DMSO-d6: 7.77 (d, 2H), 7.65 (d, 1H), 7.15 (d, 2H), 6.60 (m, 1H + 1H), 5.89 (d, 1H), 5.79 (dd, 1H), 4.64 (s, 2H), 4.58 (s, 2H), 4.17 (t, 2H), 2.68 (t, 2H), 2.50 (m, 1H), 2.06 (m, 2H), 1.65 (m, 2H), 1.6 - 0.8 (m, 13H), 0.86 (t, 3H).

[0376] Preparation of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4-pentylcyclohexyl)cyclohexanecarboxylate

[0377] 5.20 g (8.38 mmol) of [4-[(E)-3-[2-(2,4-dinitrophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4-pentylcyclohexyl)cyclohexanecarboxylate was dissolved in a mixture of 54 mL of N,N-dimethylformamide and 6 mL of water. 13.9 g (51.4 mmol) of iron(III) chloride hexahydrate was added. 5.60 g (85.7 mmol) of zinc powder was gradually added over a period of 60 minutes. The mixture was allowed to react for 2 hours.

[0378] The reaction mixture was then partitioned between ethyl acetate and water and filtered. The organic phase was washed repeatedly with water, dried over sodium sulfate, filtered and concentrated by rotary evaporation. The residue was filtered through silica gel using toluene:ethyl acetate (1:3) as the eluent and crystallized from ethyl acetate:hexane (1:1) to give 3.06 g (65%) of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4-pentylcyclohexyl)cyclohexanecarboxylate as an orange-yellow powder.

[0379] 11H NMR (300 MHz), in DMSO-D6: 7.76 (d, 2H), 7.65 (d, 1H), 7.14 (m, 2H), 6.59 (m, 1H + 1H), 5.89 (m, 1H), 5.80 (m, 1H), 4.64 (s, 2H), 4.57 (s, 2H), 4.17 (t, 2H), 3.38 (t, 2H), 2.1 (m, 2H), 1.7 (m, 6H), 1.5 - 0.7 (m, 20H), 0.85 (t, 3H).

[0380] Preparation of [4-[(E)-3-[[5-nitro-2-[4-nitro-2-[[(E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate

[0381] Dissolve 3.92 g (12.8 mmol) of 2,2'-bis(hydroxymethyl)-4,4'-dinitro-1,1'-biphenyl, 13.20 g (33.5 mmol) of (E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoic acid and 0.630 mg (5.15 mmol) of 4-dimethylaminopyridine in 200 mL of dichloromethane. Add 6.91 g (11.16 mmol) of N,N'-dicyclohexylcarbodiimide at 0 °C. Stir the solution at 0 °C for 2 hours and then at room temperature overnight.

[0382] After 22 hours at room temperature, partition the reaction mixture between dichloromethane and water. Wash the organic phase repeatedly with water, dry over sodium sulfate, filter and concentrate by rotary evaporation. Purify the residue on 150 g of silica gel, using toluene:ethyl acetate (9:1) as the eluent to obtain 12.0 g of [4-[(E)-3-[[5-nitro-2-[4-nitro-2-[[(E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate as white crystals.

[0383] MS: 1074.2 M+NH4 + , 1079.2 M+Na +

[0384] Preparation of [4-[(E)-3-[[5-amino-2-[4-amino-2-[[(E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate

[0385] Dissolve 2.27 g (2.14 mmol) of [4-[(E)-3-[[5-nitro-2-[4-nitro-2-[[(E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate in a mixture of 40 mL of N,N-dimethylformamide and 3 mL of water. Add 3.48 g (12.8 mmol) of iron(III) chloride hexahydrate. Gradually add 1.40 g (21.4 mmol) of zinc powder over 40 minutes. Allow the mixture to react for 2 hours.

[0386] Then partition the reaction mixture between ethyl acetate and water and filter. Wash the organic phase repeatedly with water, dry over sodium sulfate, filter and concentrate by rotary evaporation. Purify the residue on 100 g of silica gel using toluene:ethyl acetate (7:3) as the eluent to give 1.74 g of [4-[(E)-3-[[5-amino-2-[4-amino-2-[[(E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate as pale yellow crystals.

[0387] MS: 997.4 MH + , 1014.4 M+NH4 +

[0388] Preparation of polymers

[0389] The polymers are synthesized by solution polycondensation of diamines or mixtures of diamines with dianhydrides or mixtures of dianhydrides. The formation of the polymers is characterized by an increase in the viscosity of the reaction mixture. An intrinsic viscosity > 0.1 dL / g demonstrates the formation of the polymer backbone.

[0390] Polymer PX1

[0391] 4.897 g (24.970 mmol) of 4,9-dioxatricyclo[5.3.0.02,6]decane-3,5,8,10-tetrone was added to a solution of 5.000 g (24.970 mmol) of 4-(4-aminophenoxy)aniline in 39.59 g of NMP. The mixture was then stirred at 0 °C for 2 h. Subsequently, the mixture was allowed to react at room temperature for 72 h. Polymer PX1 was obtained as a solution (20 wt%) in NMP with an intrinsic viscosity η of 0.48 dL / g.

[0392] Polymer PX2[[ID=」4]]

[0393] 5.284 g (23.570 mmol) of 4,10-dioxatricyclo[6.3.1.02,7]dodecane-3,5,9,11-tetrone was added to a solution of 5.000 g (23.570 mmol) of 4-(4-amino-2-methylphenyl)-3-methylaniline in 41.14 g of NMP. The mixture was then stirred at 0 °C for 2 h. Subsequently, the mixture was allowed to react at room temperature for 72 h. Polyamic acid PX2 was obtained as a 20 wt% NMP solution with an intrinsic viscosity η of 0.47 dL / g.

[0394] Polymer P1

[0395] 0.840 g (3.74 mmol) of 4,10-dioxatricyclo[6.3.1.02,7]dodecane-3,5,9,11-tetrone was added to a solution of 2.000 g (3.78 mmol) of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxoprop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate and 0.038 g (0.03 mmol) of [4-[(E)-3-[[5-amino-2-[4-amino-2-[[(E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxoprop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate in 6.733 g of NMP. The mixture was then stirred at 0 °C for 2 h. Subsequently, the mixture was allowed to react at room temperature for 72 h. Polymer P1 was obtained as an NMP solution (30 wt%) with an intrinsic viscosity η of 0.27 dL / g.

[0396] Polymer P2

[0397] 0.364 g (1.85 mmol) of 4,9-dioxatricyclo[5.3.0.02,6]decane-3,5,8,10-tetrone and 0.424 g (1.89 mmol) of 4,10-dioxatricyclo[6.3.1.02,7]dodecane-3,5,9,11-tetrone were added to a solution of 2.000 g (3.78 mmol) of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate in 6.514 g of NMP. The mixture was then stirred at 0 °C for 2 h. Subsequently, the mixture was allowed to react at room temperature for 48 h. Polymer P2 was obtained as an NMP solution (30 wt%), with an intrinsic viscosity η of 0.42 dL / g.

[0398] Polymer P3

[0399] 0.468 g (2.08 mmol) of 4,10-dioxatricyclo[6.3.1.02,7]dodecane-3,5,9,11-tetrone was added to a solution of 0.828 g (1.56 mmol) of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate and 0.250 g (0.52 mmol) of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-pentylcyclohexanecarboxylate in 3.60 g of NMP. The mixture was then stirred at 0 °C for 2 h. Subsequently, the mixture was allowed to react at room temperature for 72 h. Polymer P3 was obtained as an NMP solution (30 wt%), with an intrinsic viscosity η of 0.35 dL / g.

[0400] Polymer P4

[0401] 0.499 g (2.22 mmol) of 4,10-dioxatricyclo[6.3.1.02,7]dodecane-3,5,9,11-tetrone was added to a solution of 1.000 g (1.89 mmol) of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4,4,4-trifluorobutoxy)benzoate and 0.187 g (0.33 mmol) of [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] 4-(4-pentylcyclohexyl)cyclohexanecarboxylate in 3.93 g of NMP. The mixture was then stirred at 0 °C for 2 h. Subsequently, the mixture was allowed to react at room temperature for 72 h. Polymer P4 was obtained as an NMP solution (30 wt%), with an intrinsic viscosity η of 0.41 dL / g.

[0402] Polymer P5

[0403] 50.00 g (0.20 mol) of 2-(3,4-epoxycyclohexyl)ethyl]trimethoxysilane and 5.00 g (0.05 mol) of triethylamine were heated to reflux in 250 g of MIBK. 50.00 g (2.77 mol) of deionized water was added dropwise to the mixture over 30 minutes. After stirring at 80 °C for 6 hours, the reaction mixture was cooled to room temperature, the organic layer was extracted, washed three times with deionized water and the solvent was removed under pressure to obtain poly[2-(3,4-epoxycyclohexyl)ethyl]trimethoxysilane] P5 as a viscous oil. GPC (MW = 2.5 kDa).

[0404] Polymer P6

[0405] 2.94 g (13.6 mmol) of Polymer P5, 1.61 g (4.08 mmol) of (E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoic acid, and 0.132 g (0.41 mmol) of tetrabutylammonium bromide were heated to 110 °C in 19 mL of MIBK. After stirring at 110 °C for 12 hours, the reaction mixture was cooled to room temperature and MIBK was removed in vacuo. The residue was redissolved in 100 mL of ethyl acetate and washed three times with deionized water. The solvent was removed in vacuo to obtain Polymer P6 as an off-white powder. GPC (MW = 14.3 kDa).

[0406] Polymer P7

[0407] 1.00 g (4.62 mmol) of Polymer P5, 0.215 g (0.46 mmol) of (E)-3-[4-[4-[4-(4,4,4-trifluorobutyl)cyclohexyl]cyclohexanecarbonyl]oxyphenyl]prop-2-enoic acid, 0.493 g (1.16 mmol) of (E)-3-[4-[4-(4-pentylcyclohexyl)cyclohexanecarbonyl]oxyphenyl]prop-2-enoic acid, and 0.022 g (0.07 mmol) of tetrabutylammonium bromide were heated to 110 °C in 10 mL of MIBK. After stirring at 110 °C for 12 hours, the reaction mixture was cooled to room temperature and MIBK was removed in vacuo. The residue was redissolved in 100 mL of ethyl acetate and washed three times with deionized water. The organic layer was removed under pressure to obtain Polymer P7 as an off-white powder. GPC (16.7 kDa).

[0408] A solution was prepared by dissolving the polymeric material in a solvent mixture as described below.

[0409] Solution 1

[0410] In a 30 mL plastic flask, 0.739 g of P1 and 10.142 g of PX1 were mixed with 3.312 g of NMP. Subsequently, 11.936 g of GBL, 19.098 g of BC, and 4.774 g of DEE were added. The solution was stirred vigorously for 10 minutes at room temperature and filtered through a coupled Sartorius filter (0.45 μm and 0.20 μm).

[0411] Solution 2 - 7

[0412] Solutions 2 - 7 were obtained in a similar manner to Solution 1, but using the following polymers and solvents.

[0413] Solution 2: 0.591 g of P1 and 8.113 g of PX1 mixed with 4.556 g of NMP, 11.468 g of GBL, 11.461 g of BC, and 3.821 g of DEE.

[0414] Solution 3: 0.901 g of P2 and 7.65 g of PX1 mixed with 4.714 g of NMP, 11.459 g of GBL, 11.462 g of BC, and 3.821 g of DEE.

[0415] Solution 4: 0.800 g of P2 and 6.80 g of PX1 mixed with 5.527 g of NMP, 11.524 g of GBL, 11.522 g of BC, and 3.827 g of DEE.

[0416] Solution 5: 0.592 g of P1 and 8.113 g of PX1 mixed with 4.557 g of NMP, 11.462 g of GBL, 11.462 g of BC, and 3.82 g of EEP.

[0417] Solution 6: 0.533 g of P3 and 7.201 g of PX1 mixed with 5.387 g of NMP, 11.521 g of GBL, 11.520 g of BC, and 3.84 g of DEE.

[0418] Solution 7: 0.400 g of P4 and 7.40 g of PX1 mixed with 5.320 g of NMP, 11.521 g of GBL, 11.521 g of BC, and 3.843 g of DEE.

[0419] Solution 8: 0.800 g of P2 and 6.805 g of PX2 mixed with 5.517 g of NMP, 11.520 g of GBL, 11.462 g of BC, and 3.842 g of DEE.

[0420] Solution 9: 0.400 g of P6 and 7.601 g of PX1 mixed with 5.121 g of NMP, 11.522 g of GBL, 11.522 g of BC, and 3.840 g of DEE.

[0421] Solution 10: 0.016 g of P7 and 7.920 g of PX1 mixed with 5.185 g of NMP, 11.520 g of GBL, 9.60 g of BC, and 5.761 g of DEE.

[0422]

[0423] * Comparative Example

[0424] The solutions were examined according to the above method. The results are shown in the following table.

[0425]

[0426]

[0427] * Comparative Example ** Average thickness is 107 nm

[0428] *** + indicates that visual non-uniformity was not observed; - indicates that visual non-uniformity was observed

[0429] The film thickness variation of each film in the membrane is within ±3 nm. Apparently, the composition of the present invention can obtain a uniform liquid crystal alignment film without visual non-uniformity, and compared with the comparative example, the composition exhibits reduced diffusion and increased minimum thickness.

Claims

1. A composition for forming a liquid crystal alignment film, comprising: - A photoalignment polymer material for forming a liquid crystal alignment film, having a side chain containing a photoalignment group; and - A solvent mixture, relative to the weight of the solvent mixture, the solvent mixture comprising (i) at least one of N-alkylpyrrolidone and lactone in an amount of 45-70 wt%, (ii) diethylene glycol dialkyl ether in an amount of 5-15 wt%, and (iii) ethylene glycol monoalkyl ether in an amount such that the total amount of the solvent mixture is 100 wt%; wherein the composition has a solid content of 3.0-6.0 wt%.

2. The composition according to claim 1, wherein the solvent mixture simultaneously contains N-alkylpyrrolidone and lactone.

3. The composition according to claim 2, wherein relative to the weight of the solvent mixture, the solvent mixture contains 20-40 wt% of N-alkylpyrrolidone and 20-40 wt% of lactone, provided that the amounts of N-alkylpyrrolidone and lactone total 45-70 wt%.

4. The composition according to any one of the preceding claims, wherein the N-alkylpyrrolidone is N-methylpyrrolidone, the lactone is γ-butyrolactone, the ethylene glycol monoalkyl ether is ethylene glycol monobutyl ether, and the diethylene glycol dialkyl ether is diethylene glycol diethyl ether.

5. The composition according to any one of the preceding claims, wherein the photoalignment group is selected from cinnamate and chalcone, coumarin and quinolone, stilbene and cyanostilbene, azo group, chromone and chromene, monoethynyl and diethynyl groups (such as diphenylacetylene group), benzylidene phthalimide group, benzylidene acetophenone group, benzodiallyl group, wherein the photoalignment group is optionally substituted.

6. The composition according to any one of the preceding claims, wherein in addition to the photoalignment group, the side chain further contains one or more aromatic groups or alicyclic groups.

7. The composition according to any one of the preceding claims, wherein the main chain of the photoalignment polymer material is selected from polyamic acid, polyimide, polyamide, polysiloxane, polymaleimide and polyacrylate.

8. The composition according to any one of the preceding claims, wherein the polymer material for forming a liquid crystal alignment film is obtained by polymerizing at least one diamine with an acid dianhydride, wherein at least a part of the diamine has at least one photoalignment group.

9. The composition according to claim 8, wherein the polymer material for forming a liquid crystal alignment film contains a repeating unit represented by the following formula (1): wherein Q is a tetravalent residue of a tetracarboxylic dianhydride, and P is a divalent residue of a diamine, wherein at least a part of P has a side chain containing a photoalignment group.

10. The composition according to any one of the preceding claims, which contains an additional polymer material.

11. A method for forming a liquid crystal alignment film, comprising: - Applying the composition according to claim 1 to a substrate, - Drying the resulting wet film, and - Irradiating the dried film to impart liquid crystal alignment ability.

12. A liquid crystal alignment film obtained by the method according to claim 11.

13. Structured or unstructured optical and electro-optical elements and devices comprising the liquid crystal alignment film according to claim 12.

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