Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
  • G02F1/133711—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by organic films, e.g. polymeric films
  • G02F1/133723—Polyimide, polyamide-imide
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C217/00—Compounds containing amino and etherified hydroxy groups bound to the same carbon skeleton
  • C07C217/78—Compounds containing amino and etherified hydroxy groups bound to the same carbon skeleton having amino groups and etherified hydroxy groups bound to carbon atoms of six-membered aromatic rings of the same carbon skeleton
  • C07C217/80—Compounds containing amino and etherified hydroxy groups bound to the same carbon skeleton having amino groups and etherified hydroxy groups bound to carbon atoms of six-membered aromatic rings of the same carbon skeleton having amino groups and etherified hydroxy groups bound to carbon atoms of non-condensed six-membered aromatic rings
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
  • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
  • C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L79/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen or carbon only, not provided for in groups C08L61/00 - C08L77/00
  • C08L79/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
  • C08L79/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/52—Liquid crystal materials characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
  • C09K19/54—Additives having no specific mesophase characterised by their chemical composition
  • C09K19/542—Macromolecular compounds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/52—Liquid crystal materials characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
  • C09K19/54—Additives having no specific mesophase characterised by their chemical composition
  • C09K19/56—Aligning agents
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2323/00—Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
  • C09K2323/02—Alignment layer characterised by chemical composition
  • C09K2323/027—Polyimide

Definitions

• the present invention relates to a liquid crystal aligning agent used for manufacturing a liquid crystal display element, a liquid crystal aligning film obtained from the liquid crystal aligning agent, and a liquid crystal display element having the liquid crystal aligning film.
• the photo-alignment method is an industrially simple manufacturing process as a rubbingless alignment treatment method.
• a rubbing treatment method can be obtained by using the liquid crystal alignment film obtained by the above optical alignment method.
• the contrast and viewing angle characteristics of the liquid crystal display device can be expected to be improved as compared with the liquid crystal alignment film (Patent Document 1). This makes it possible to improve the performance of the liquid crystal display device, and has been attracting attention as a promising liquid crystal alignment treatment method.
• the liquid crystal alignment film obtained by the optical alignment method has a problem that the anisotropy with respect to the alignment direction of the polymer film is smaller than that obtained by rubbing. If the anisotropy is small, sufficient liquid crystal alignment cannot be obtained, and when a liquid crystal display device is formed, problems such as the occurrence of an afterimage occur (Non-Patent Document 1).
• An object of the present invention is to suppress the occurrence of afterimages after AC driving due to insufficient anisotropy in the alignment direction of the liquid crystal alignment film obtained by the photo-alignment method.
• a liquid crystal aligning agent containing in the main chain at least one polymer selected from the group consisting of a polyimide precursor having a structure represented by the following formula (1) and an imidized polymer of the polyimide precursor.
• R 1 and R 2 are each independently a single bond, —O—, —S—, —NR 12 —, ester bond, amide bond, thioester bond, urea bond, carbonate bond, or carbamate bond.
• R 12 is a hydrogen atom or a methyl group.
• A is an alkylene group having 1 or 2 carbon atoms.
• B 1 and B 2 are divalent organic groups having the same structure and selected from the following structures.
• R 4 is an alkylene group having 1 to 5 carbon atoms.
• R 5 is a hydrogen atom, a methyl group, a hydroxy group or a methoxy group.
• liquid crystal aligning agent of the present invention By using the liquid crystal aligning agent of the present invention, it becomes possible to obtain a liquid crystal aligning film having a high liquid crystal aligning property and capable of suppressing the generation of an AC afterimage.
• the liquid crystal aligning agent of the present invention it is not always clear why the above effects are obtained, but the chemical structure of the diamine used as the raw material of the polymer constituting the liquid crystal aligning material is rigid, and It is presumed that it has a symmetrical structure.
• R 1 and R 2 are each independently a single bond, —O—, —S—, —NR 12 —, ester bond, amide bond, thioester bond, urea bond, carbonate bond, Alternatively, it is a carbamate bond, and R 12 is a hydrogen atom or a methyl group.
• A is an alkylene group having 1 or 2 carbon atoms.
• B 1 and B 2 are divalent organic groups having the same structure and selected from the following structures. Since B 1 and B 2 have the same structure, a liquid crystal alignment film having high liquid crystal alignment can be obtained.
• R 4 is an alkylene group having 1 to 5 carbon atoms.
• R 5 is a hydrogen atom, a methyl group, a hydroxy group or a methoxy group.
• R 1 and R 2 are preferably a single bond, —O—, —S—, —NR 12 —, an ester bond or an amide bond, from the viewpoint of liquid crystal alignment. -O- is particularly preferable.
• R 12 is preferably a hydrogen atom or a methyl group.
• A is preferably an alkylene group having a carbon chain 2 from the viewpoint of liquid crystal alignment.
• B 1 and B 2 are preferably biphenylene groups.
• R 4 is preferably an alkylene group having 1 to 3 carbon atoms from the viewpoint of liquid crystal alignment.
• R 5 is preferably a hydrogen atom or a methyl group.
• the specific structure described above is preferably contained in the diamine which is the raw material of the polyimide precursor.
• the diamine having the above-mentioned specific structure include, but are not limited to, the following diamines.
• the polyimide precursor is preferably obtained by polymerizing a diamine component containing at least one diamine selected from the following diamines and a tetracarboxylic acid component.
• R 5 and R 12 have the same definitions as above, including the respective preferable examples.
• the diamine having the above-mentioned specific structure is preferably a diamine in which amino groups are bound to both ends of the above-mentioned specific structure, and among them, from the viewpoint of alignment properties and reduction of bright spots in a liquid crystal display device, the following diamines are used. Is preferred.
• R 1 , R 2 , and A are as described above, including preferred examples thereof.
• the diamine having the above specific structure the following diamines are preferable.
• the polyimide precursor constituting the liquid crystal aligning agent of the present invention contains a structural unit represented by the following formula (2).
• X 1 is at least one selected from the group consisting of structures represented by the following formulas (X1-1) and (X1-2). Among them, the following formula (X1-2) is preferable from the viewpoint of liquid crystal alignment.
• Y 1 is a divalent organic group represented by the formula (1).
• R 3 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a propyl group, an i-propyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group and an n-pentyl group. From the viewpoint of ease of imidization by heating, R 3 is preferably a hydrogen atom or a methyl group.
• Z 1 and Z 2 are each independently a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms or an alkynyl group having 2 to 10 carbon atoms. It is a base.
• the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, a hexyl group, an octyl group, a decyl group, a cyclopentyl group, a cyclohexyl group and a bicyclohexyl group.
• Alkenyl groups include those in which one or more CH 2 —CH 2 structures present in the above alkyl groups have been replaced with a CH ⁇ CH structure. Specifically, vinyl group, allyl group, 1-propenyl group, isopropenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, 2-hexenyl group, cyclopropenyl group, cyclopentenyl group, A cyclohexenyl group etc. are mentioned.
• alkynyl group include those in which one or more CH 2 —CH 2 structures present in the above alkyl group are replaced with a C ⁇ C structure. Specific examples thereof include an ethynyl group, a 1-propynyl group and a 2-propynyl group.
• the above alkyl group, alkenyl group, and alkynyl group may have a substituent, and depending on the substituent, a ring structure may be formed.
• forming a ring structure by a substituent means that the substituents are bonded to each other or a part of the mother skeleton to form a ring structure.
• the substituent include a halogen group, a hydroxyl group, a thiol group, a nitro group, an aryl group, an organooxy group, an organothio group, an organosilyl group, an acyl group, an ester group, a thioester group, a phosphoric ester group, an amide group, an alkyl group.
• alkenyl group alkynyl group and the like.
• halogen group examples include a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.
• a phenyl group is mentioned as an aryl group. This aryl group may be further substituted with another substituent described above.
• the organooxy group can have a structure represented by —OR.
• the R may be the same or different, and examples thereof include the above-mentioned alkyl group, alkenyl group, alkynyl group and aryl group. These R may be further substituted with the above-mentioned substituents. Specific examples thereof include a methoxy group, an ethoxy group, a propyloxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group and an octyloxy group.
• the organothio group can have a structure represented by —SR.
• R examples include the alkyl group, alkenyl group, alkynyl group, and aryl group described above. These R may be further substituted with the above-mentioned substituents. Specific examples thereof include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group and an octylthio group.
• the organosilyl group can have a structure represented by —Si— (R) 3 .
• the R's may be the same or different, and examples thereof include the above-mentioned alkyl group, alkenyl group, alkynyl group and aryl group. These R may be further substituted with the above-mentioned substituents. Specific examples include a trimethylsilyl group, a triethylsilyl group, a tripropylsilyl group, a tributylsilyl group, a tripentylsilyl group, a trihexylsilyl group, a pentyldimethylsilyl group and a hexyldimethylsilyl group.
• the acyl group can have a structure represented by —C (O) —R.
• R include the alkyl group, alkenyl group, and aryl group described above. These R may be further substituted with the above-mentioned substituents. Specific examples thereof include a formyl group, an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a valeryl group, an isovaleryl group and a benzoyl group.
• ester group a structure represented by -C (O) OR or -OC (O) -R can be shown.
• R include the alkyl group, alkenyl group, alkynyl group, and aryl group described above. These R may be further substituted with the above-mentioned substituents.
• the thioester group can have a structure represented by -C (S) OR or -OC (S) -R.
• R include the alkyl group, alkenyl group, alkynyl group, and aryl group described above. These R may be further substituted with the above-mentioned substituents.
• the phosphate group can have a structure represented by —OP (O) — (OR) 2 .
• the R's may be the same or different, and examples thereof include the above-mentioned alkyl group, alkenyl group, alkynyl group and aryl group. These R may be further substituted with the above-mentioned substituents.
• the amide group has a structure represented by -C (O) NH 2 , -C (O) NHR, -NHC (O) R, -C (O) N (R) 2 or -NRC (O) R.
• the R's may be the same or different, and examples thereof include the above-mentioned alkyl group, alkenyl group, alkynyl group and aryl group. These R may be further substituted with the above-mentioned substituents.
• the aryl group the same aryl groups as described above can be mentioned. This aryl group may be further substituted with another substituent described above.
• the alkyl group the same ones as those mentioned above can be mentioned.
• the alkyl group may be further substituted with the other substituent described above.
• the alkenyl group the same alkenyl groups as mentioned above can be mentioned. This alkenyl group may be further substituted with the other substituent described above.
• the alkynyl group the same alkynyl groups as described above can be mentioned. This alkynyl group may be further substituted with the other substituent described above.
• Z 1 and Z 2 each have a hydrogen atom or a carbon number of 1 which may have a substituent.
• Alkyl groups of to 5 are more preferable, and hydrogen atom, methyl group or ethyl group is particularly preferable.
• the structural unit represented by the above formula (2) is preferably contained in an amount of 20 to 100 mol% based on all structural units, and from the viewpoint of liquid crystal alignment, 30 to 100 mol% is particularly preferable.
• X 2 is a tetravalent organic group, and Y 2 is a divalent organic group.
• X 2 is a tetravalent organic group derived from a tetracarboxylic acid derivative, and its structure is not particularly limited. Two or more types of X 2 may be mixed in the polyimide precursor. Specific examples of X 2 include the structures of the following formulas (X-1) to (X-44).
• R 8 to R 11 in the above formula (X-1) are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkyl group having 2 to 6 carbon atoms. It is an alkynyl group or a phenyl group.
• R 8 to R 11 have a bulky structure, the liquid crystal alignment may be deteriorated, and therefore a hydrogen atom, a methyl group or an ethyl group is more preferable, and a hydrogen atom or a methyl group is particularly preferable.
• Y 2 is a divalent organic group derived from diamine, and its structure is not particularly limited. Specific examples of the structure of Y 2 include the following (Y-1) to (Y-118).
• m and n are each independently an integer of 1 to 11
• m + n is an integer of 2 to 12
• h is 1 to 3
• j is an integer of 0 to 3 in formulas (Y-111) and (Y-117).
• the polyimide precursor used in the present invention is obtained from the reaction of a diamine component and a tetracarboxylic acid derivative, and examples thereof include polyamic acid and polyamic acid ester.
• the polyamic acid which is the polyimide precursor used in the present invention, is produced by the following method. Specifically, tetracarboxylic dianhydride and diamine are reacted in the presence of an organic solvent at ⁇ 20 to 150 ° C., preferably 0 to 50 ° C. for 30 minutes to 24 hours, preferably 1 to 12 hours. Can be synthesized.
• the reaction between the diamine component and the tetracarboxylic acid component is usually performed in an organic solvent.
• the organic solvent used at that time is not particularly limited as long as it can dissolve the generated polyimide precursor. Specific examples of the organic solvent used in the reaction are shown below, but the invention is not limited to these examples. Examples include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, ⁇ -butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide or 1,3-dimethyl-imidazolidinone. Be done.
• the polyimide precursor When the polyimide precursor has high solubility, it is represented by methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone or the following formulas [D-1] to [D-3].
• the organic solvent used can be used.
• D 1 represents an alkyl group having 1 to 3 carbon atoms
• D 2 represents an alkyl group having 1 to 3 carbons
• D 3 represents an alkyl group having 1 to 4 carbon atoms.
• solvents may be used alone or in combination. Furthermore, even a solvent that does not dissolve the polyimide precursor may be used as a mixture with the solvent as long as the generated polyimide precursor does not precipitate. Further, water in the solvent inhibits the polymerization reaction and causes hydrolysis of the formed polyimide precursor, and therefore it is preferable to use a dehydrated and dried solvent.
• concentration of the polyamic acid polymer in the reaction system is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation does not easily occur and a high molecular weight polymer is easily obtained.
• the polyamic acid obtained as described above can be recovered by precipitating a polymer by injecting it into a poor solvent while stirring the reaction solution well. Further, by performing precipitation several times, washing with a poor solvent, and drying at room temperature or by heating, a purified polyamic acid powder can be obtained.
• the poor solvent is not particularly limited, and examples thereof include water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.
• the polyamic acid ester which is the polyimide precursor used in the present invention, can be produced by the following production method (1), (2) or (3).
• the polyamic acid ester can be produced by esterifying the polyamic acid produced as described above. Specifically, it is produced by reacting a polyamic acid and an esterifying agent in the presence of an organic solvent at ⁇ 20 to 150 ° C., preferably 0 to 50 ° C. for 30 minutes to 24 hours, preferably 1 to 4 hours. be able to.
• esterifying agent those which can be easily removed by purification are preferable, and N, N-dimethylformamide dimethyl acetal, N, N-dimethylformamide diethyl acetal, N, N-dimethylformamide dipropyl acetal, N, N-dimethylformamide Dineopentylbutyl acetal, N, N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p -Tolyltriazene, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride and the like can be mentioned.
• the addition amount of the esterifying agent is preferably 2 to 6 molar equivalents with respect to 1 mol of the repeating unit of the polyamic acid.
• organic solvent examples include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or ⁇ -butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide or 1,3-dimethyl- Examples include imidazolidinone.
• the polyimide precursor has high solubility in a solvent, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the above formula [D-1] to formula [D-3] is used.
• the indicated solvents can be used. These solvents may be used alone or as a mixture.
• a solvent that does not dissolve the polyimide precursor may be used as a mixture with the solvent as long as the generated polyimide precursor does not precipitate. Further, since water in the solvent hinders the polymerization reaction and causes hydrolysis of the generated polyimide precursor, it is preferable to use a dehydrated and dried solvent.
• the solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, or ⁇ -butyrolactone because of the solubility of the polymer. These are used alone or in combination of two or more. Good.
• the concentration at the time of production is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, because precipitation of a polymer is less likely to occur and a high molecular weight product is easily obtained.
• the polyamic acid ester can be produced from tetracarboxylic acid diester dichloride and diamine. Specifically, tetracarboxylic acid diester dichloride and diamine are added in the presence of a base and an organic solvent at ⁇ 20 to 150 ° C., preferably 0 to 50 ° C. for 30 minutes to 24 hours, preferably 1 to 4 hours. It can be produced by reacting.
• pyridine triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable because the reaction proceeds gently.
• the amount of the base added is preferably 2 to 4 times the molar amount of the tetracarboxylic acid diester dichloride from the viewpoints of easy removal and easily obtaining a high molecular weight product.
• the solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or ⁇ -butyrolactone in view of the solubility of the monomer and polymer, and these may be used alone or in combination of two or more.
• the polymer concentration during production is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass, because precipitation of the polymer is less likely to occur and a high molecular weight product is easily obtained.
• the solvent used for the production of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent the entry of outside air in a nitrogen atmosphere.
• the polyamic acid ester can be produced by polycondensing the tetracarboxylic acid diester and diamine. Specifically, a tetracarboxylic acid diester and a diamine are mixed in the presence of a condensing agent, a base, and an organic solvent at 0 to 150 ° C., preferably 0 to 100 ° C. for 30 minutes to 24 hours, preferably 3 to It can be produced by reacting for 15 hours.
• condensing agent examples include triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N'-carbonyldiimidazole, dimethoxy-1,3,5-triazine.
• Nylmethylmorpholinium O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethyluronium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N , N ′, N′-tetramethyluronium hexafluorophosphate, diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate and the like can be used.
• the amount of the condensing agent added is preferably 2 to 3 times the mol of the tetracarboxylic acid diester.
• tertiary amines such as pyridine and triethylamine can be used.
• the amount of the base added is preferably 2 to 4 times the molar amount of the diamine component from the viewpoint of easy removal and easy production of a high molecular weight product.
• the reaction proceeds efficiently by adding Lewis acid as an additive.
• Lewis acid lithium halides such as lithium chloride and lithium bromide are preferable.
• the Lewis acid is preferably added in an amount of 0 to 1.0 times the mol of the diamine component.
• the production method (1) or (2) is particularly preferable because a high molecular weight polyamic acid ester can be obtained.
• the solution of the polyamic acid ester obtained as described above can be poured into a poor solvent while stirring well to precipitate the polymer. Precipitation is carried out several times, and after washing with a poor solvent, it is dried at room temperature or by heating to obtain a purified polyamic acid ester powder.
• the poor solvent is not particularly limited, and examples thereof include water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.
• the polyimide used in the present invention can be produced by imidizing the above-mentioned polyamic acid ester or polyamic acid.
• a polyimide is produced from a polyamic acid ester
• chemical imidization by adding a basic catalyst to a polyamic acid ester solution or a polyamic acid solution obtained by dissolving a polyamic acid ester resin powder in an organic solvent is simple.
• Chemical imidation is preferable because the imidization reaction proceeds at a relatively low temperature and the decrease in the molecular weight of the polymer does not easily occur during the imidization process.
• the chemical imidization can be performed by stirring the polyamic acid ester to be imidized in an organic solvent in the presence of a basic catalyst.
• a basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Of these, triethylamine is preferable because it has a basicity sufficient to allow the reaction to proceed.
• the temperature at which the imidization reaction is carried out is ⁇ 20 to 140 ° C., preferably 0 to 100 ° C., and the reaction time is preferably 1 to 100 hours.
• the amount of the basic catalyst is 0.5 to 30 times, preferably 2 to 20 times the amount of the amic acid ester group.
• the imidation ratio of the obtained polymer can be controlled by adjusting the amount of catalyst, temperature, reaction time and the like. Since the added catalyst and the like remain in the solution after the imidization reaction, the resulting imidized polymer is recovered by the means described below and redissolved in an organic solvent to obtain the liquid crystal alignment of the present invention. It is preferable to use it as an agent.
• a polyimide is produced from a polyamic acid
• chemical imidization by adding a catalyst to a solution of the polyamic acid obtained by the reaction of a diamine component and a tetracarboxylic dianhydride is simple.
• Chemical imidization is preferable because the imidization reaction proceeds at a relatively low temperature and the decrease in the molecular weight of the polymer does not easily occur in the process of imidization.
• the chemical imidization can be performed by stirring the polyamic acid to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride.
• the organic solvent the solvent used in the above-mentioned polymerization reaction can be used.
• Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Of these, pyridine is preferable because it has a proper basicity for proceeding the reaction.
• Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride and the like. Of these, acetic anhydride is preferable because it facilitates purification after the reaction.
• the temperature at which the imidization reaction is carried out is ⁇ 20 to 140 ° C., preferably 0 to 100 ° C., and the reaction time is preferably 1 to 100 hours.
• the amount of the basic catalyst is 0.5 to 30 times, preferably 2 to 20 times the amount of the amic acid group, and the amount of the acid anhydride is 1 to 50 times, preferably 3 to the molar amount of the amic acid group. It is 30 mol times.
• the imidation ratio of the obtained polymer can be controlled by adjusting the amount of catalyst, temperature, reaction time and the like.
• the liquid crystal aligning agent of the present invention is preferable.
• the polymer can be precipitated by injecting the solution of the polyimide obtained as described above into a poor solvent while stirring well. Precipitation is performed several times, washed with a poor solvent, and then dried at room temperature or by heating to obtain a purified polyimide powder.
• the poor solvent is not particularly limited, but includes methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene and the like.
• the liquid crystal aligning agent of the present invention contains at least one polymer selected from the group consisting of a polyimide precursor having a specific structure in the main chain and an imidized polymer of the polyimide precursor.
• the weight average molecular weight (Mw) of the polymer is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, and further preferably 10,000 to 100,000.
• the number average molecular weight (Mn) is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and further preferably 5,000 to 50,000. ..
• the concentration of the polymer in the liquid crystal aligning agent of the present invention can be appropriately changed depending on the setting of the thickness of the coating film to be formed, but from the viewpoint of forming a uniform and defect-free coating film, It is preferably not less than 10% by mass, and more preferably not more than 10% by mass from the viewpoint of storage stability of the solution.
• the concentration of the polymer is preferably 2 to 7% by mass.
• the organic solvent that dissolves the polymer (hereinafter, also referred to as a good solvent) contained in the liquid crystal aligning agent used in the present invention is not particularly limited as long as the polymer can be uniformly dissolved therein.
• a good solvent for example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, ⁇ -butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone , Cyclohexanone, cyclopentanone or 4-hydroxy-4-methyl-2-pentanone.
• N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or ⁇ -butyrolactone is preferably used.
• the content of the good solvent in the liquid crystal aligning agent of the present invention is preferably 20 to 99 mass% of the whole solvent contained in the liquid crystal aligning agent. Above all, 20 to 90 mass% is preferable. More preferably, it is 30 to 80% by mass.
• a solvent also referred to as a poor solvent
• a poor solvent that improves the coating property and surface smoothness of the liquid crystal aligning film when the liquid crystal aligning agent is applied
• Specific examples of the poor solvent will be given.
• ethanol isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol , 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2- Etanji 1,2-propanediol, 1,3-propan
• 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether, ethylene glycol monobutyl ether or dipropylene glycol dimethyl ether is preferable.
• the content of these poor solvents is preferably 1 to 80% by mass based on the whole solvent contained in the liquid crystal aligning agent. Among them, 10 to 80 mass% is preferable, and 20 to 70 mass% is more preferable.
• the liquid crystal aligning agent of the present invention may be a polymer other than the polymer of the present invention, a dielectric or conductive substance for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal aligning film, and the liquid crystal aligning film.
• a silane coupling agent for the purpose of improving the adhesion to the substrate, a crosslinkable compound for the purpose of increasing the hardness and density of the film when it is formed into a liquid crystal alignment film, and further a polyimide precursor when baking the coating film.
• An imidation promoter for the purpose of efficiently promoting imidization by heating may be added.
• the liquid crystal alignment film of the present invention is a film obtained by applying the above liquid crystal alignment agent to a substrate, drying and baking.
• the substrate on which the liquid crystal aligning agent is applied is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a silicon nitride substrate, an acrylic substrate, a plastic substrate such as a polycarbonate substrate, or the like can be used for driving the liquid crystal. It is preferable to use a substrate on which the ITO electrode or the like is formed from the viewpoint of simplifying the process. Further, in the reflective liquid crystal display element, an opaque material such as a silicon wafer can be used if only one substrate is used, and in this case, a material such as aluminum that reflects light can be used for the electrode.
• Examples of the method for applying the liquid crystal aligning agent of the present invention include a spin coating method, a printing method and an inkjet method. Any temperature and time can be selected for the drying and firing steps after applying the liquid crystal aligning agent.
• the drying temperature is preferably 50 to 120 ° C., and the drying time is preferably 1 to 10 minutes.
• the firing temperature is preferably 150 to 300 ° C., and the firing time is preferably 5 to 120 minutes.
• the thickness of the film after firing is not particularly limited, but if it is too thin, the reliability of the liquid crystal display element may be impaired, so it is preferably 5 to 300 nm, more preferably 10 to 120 nm.
• the coating film surface is irradiated with radiation polarized in a certain direction, and in some cases, further heat-treated at a temperature of 150 to 250 ° C. to impart liquid crystal alignment ability.
• the coating substrate may be irradiated with radiation while being heated at 50 to 250 ° C.
• the dose of radiation is preferably 1 ⁇ 10,000mJ / cm 2, particularly preferably 100 ⁇ 5,000mJ / cm 2.
• the liquid crystal alignment film manufactured as described above can stably align liquid crystal molecules in a certain direction.
• the extinction ratio of linearly polarized ultraviolet light is preferably 10: 1 or more, more preferably 20: 1 or more.
• the film irradiated with polarized radiation may then be contact-treated with a solvent containing at least one selected from water and organic solvents.
• the solvent used for the contact treatment is not particularly limited as long as it is a solvent that dissolves a decomposition product generated by light irradiation.
• Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, 3- Methyl methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate and the like can be mentioned. Two or more kinds of these solvents may be used in combination.
• At least one selected from the group consisting of water, 2-propanol, 1-methoxy-2-propanol and ethyl lactate is more preferable.
• Particularly preferred is water, 2-propanol, or a mixed solvent of water and 2-propanol.
• examples of the contact treatment of the film irradiated with polarized radiation and the solution containing an organic solvent include a dipping treatment and a spray (spray) treatment, and treatment for sufficiently contacting the membrane and the liquid. Is preferred. Above all, a method of immersing the membrane in a solution containing an organic solvent for preferably 10 seconds to 1 hour, more preferably 1 to 30 minutes is preferable.
• the contact treatment may be carried out at room temperature or with heating, but is preferably carried out at 10 to 80 ° C, more preferably 20 to 50 ° C.
• a means for enhancing contact with ultrasonic waves or the like can be provided.
• the film subjected to the contact treatment with a solvent may be heated at 150 ° C. or higher for the purpose of drying the solvent and reorienting the molecular chains in the film.
• the heating temperature is preferably 150 to 300 ° C. Higher temperature promotes reorientation of molecular chains, but too high temperature may cause decomposition of molecular chains. Therefore, the heating temperature is more preferably 180 to 250 ° C, particularly preferably 200 to 230 ° C. If the heating time is too short, the effect of reorientation of the molecular chain may not be obtained, and if it is too long, the molecular chain may be decomposed, so that it is preferably 10 seconds to 30 minutes. 10 minutes is more preferred.
• the liquid crystal display device of the present invention is a device obtained by preparing a liquid crystal cell by a known method after obtaining a substrate having a liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention, and using the cell as a device. is there.
• a liquid crystal display element having a passive matrix structure will be described below as an example.
• a liquid crystal display element having an active matrix structure in which a switching element such as a TFT (Thin Film Transistor) is provided in each pixel portion that constitutes image display may be used.
• a transparent glass substrate is prepared, and a common electrode is provided on one substrate and a segment electrode is provided on the other substrate.
• These electrodes can be, for example, ITO electrodes, and are patterned to display a desired image.
• an insulating film is provided on each substrate so as to cover the common electrodes and the segment electrodes.
• the insulating film can be, for example, a film made of SiO 2 —TiO 2 formed by the sol-gel method.
• the liquid crystal alignment film of the present invention is formed on each substrate.
• one substrate is placed on the other substrate so that their alignment film surfaces face each other, and the periphery is bonded with a sealing material.
• a spacer in the sealing material In order to control the substrate gap, it is usually preferable to mix a spacer in the sealing material.
• a part of the sealing material is usually provided with an opening that can
• a liquid crystal material is injected into the space surrounded by the two substrates and the sealing material through the opening provided in the sealing material. Then, this opening is sealed with an adhesive.
• a vacuum injection method may be used, or a method utilizing a capillary phenomenon in the atmosphere may be used.
• a polarizing plate is installed. Specifically, a pair of polarizing plates are attached to the surfaces of the two substrates opposite to the liquid crystal layer.
• the liquid crystal display element of the present invention can be obtained through the above steps.
• the sealant for example, a resin having a reactive group such as an epoxy group, an acryloyl group, a methacryloyl group, a hydroxy group, an allyl group, or an acetyl group, which is cured by ultraviolet irradiation or heating is used.
• a resin having a reactive group such as an epoxy group, an acryloyl group, a methacryloyl group, a hydroxy group, an allyl group, or an acetyl group, which is cured by ultraviolet irradiation or heating is used.
• a cured resin system having both reactive groups of epoxy group and (meth) acryloyl group.
• An inorganic filler may be added to the above-mentioned sealing agent for the purpose of improving adhesiveness, moisture resistance and the like.
• the inorganic filler that can be used is not particularly limited, and specifically, spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, sulfuric acid.
• spherical silica, fused silica, crystalline silica titanium oxide, titanium black, silicon nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, calcium silicate, aluminum silicate. And so on. You may use the said inorganic filler in mixture of 2 or more types.
• NMP N-methyl-2-pyrrolidone
• BCS Butyl cellosolve
• Fmoc represents a 9-fluorenylmethyloxycarbonyl group
• Boc represents a t-butoxycarbonyl group
• a liquid crystal cell having the structure of the FFS mode liquid crystal display device was produced. First, a substrate with electrodes was prepared. The substrate is a 30 mm ⁇ 50 mm rectangular glass plate having a thickness of 0.7 mm. On the substrate, an ITO electrode having a solid pattern, which constitutes a counter electrode as a first layer, is formed. A SiN (silicon nitride) film formed by the CVD method is formed as a second layer on the counter electrode of the first layer. The film thickness of the second-layer SiN film is 500 nm and functions as an interlayer insulating film.
• a comb-teeth-shaped pixel electrode formed by patterning an ITO film as a third layer is arranged on the second-layer SiN film to form two pixels of a first pixel and a second pixel. ing.
• the size of each pixel is 10 mm in length and about 5 mm in width.
• the first-layer counter electrode and the third-layer pixel electrode are electrically insulated by the action of the second-layer SiN film.
• the pixel electrode of the third layer has a comb-tooth shape formed by arranging a plurality of "dogleg” -shaped electrode elements whose central portion is bent at an internal angle of 160 °.
• the width of each electrode element in the lateral direction is 3 ⁇ m, and the distance between the electrode elements is 6 ⁇ m.
• the pixel electrode that forms each pixel is configured by arranging a plurality of curved "dogleg" -shaped electrode elements in the central portion, so the shape of each pixel is not rectangular, but is similar to that of the electrode element. It has a shape that resembles a bold "dogleg" bent at a part.
• Each pixel is divided into upper and lower parts with a central bent portion as a boundary, and has a first region on the upper side and a second region on the lower side of the bent portion.
• the prepared substrate with electrodes and a glass substrate having a columnar spacer with a height of 4 ⁇ m on which an ITO film is formed on the back surface are prepared. It was applied by spin coating. After drying for 2 minutes on a hot plate at 80 ° C., baking was performed for 30 minutes in a hot air circulation type oven at 230 ° C. to form a coating film having a thickness of 100 nm. This coating film surface was irradiated with polarized ultraviolet rays so as to have a dose of 500 mJ / cm 2 and subjected to an alignment treatment to obtain a substrate with a liquid crystal alignment film.
• the liquid crystal alignment film formed on the electrode-attached substrate is a liquid crystal alignment film formed on the second glass substrate by performing alignment treatment so that the direction that equally divides the interior angle of the pixel bend portion and the liquid crystal alignment direction are orthogonal to each other. Is subjected to alignment treatment so that the alignment direction of the liquid crystal on the first substrate and the alignment direction of the liquid crystal on the second substrate coincide with each other when the liquid crystal cell is manufactured.
• Set the above two substrates as a set print the sealant on the substrate, and bond the other substrate so that the alignment direction where the liquid crystal alignment film surfaces face each other becomes 0 °, and then cure the sealant. Then, an empty cell was produced.
• Liquid crystal MLC-3019 (manufactured by Merck Ltd.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS driven liquid crystal cell. After that, the obtained liquid crystal cell was heated at 110 ° C. for 1 hour, left to stand overnight, and then used for evaluation of afterimage.
• the rotation angle when the liquid crystal cell was rotated from the angle where the second region of the first pixel was darkest to the angle where the first region was darkest was calculated as the angle ⁇ .
• the second region and the first region were compared, and the same angle ⁇ was calculated.
• the average value of the angle ⁇ values of the first pixel and the second pixel was calculated as the angle ⁇ of the liquid crystal cell.
• An angle ⁇ of 0.15 ° or more of the liquid crystal cell obtained above was evaluated as “x”, less than 0.15 ° was evaluated as “ ⁇ ”, and less than 0.1 ° was evaluated as “ ⁇ ”.
• Example 1 6.25 g of the polyamic acid solution (PAA-4) obtained in Synthesis Example 5 was weighed into a 50 mL Erlenmeyer flask containing a stirring bar. Next, 3.50 g of NMP and 4.5 g of BCS were added and stirred overnight with a magnetic stirrer to obtain a liquid crystal aligning agent (AL-4).
• PAA-4 polyamic acid solution
• Example 2 2.50 g of the polyamic acid solution (PAA-4) obtained in Synthesis Example 5 and 3.75 g of the polyamic acid solution (PAA-5) obtained in Synthesis Example 6 were placed in a 50 mL Erlenmeyer flask containing a stirring bar. I took it. 3.50 g of NMP and 4.50 g of BCS were added, 0.75 g of 10% NMP solution of AD-1 and 0.113 g of AD-2 were added, and the mixture was stirred overnight with a magnetic stirrer for liquid crystal aligning agent (AL-5). Got By storing AL-5 in an environment of ⁇ 20 ° C., the stability during frozen storage was confirmed. After 1 month of frozen storage, it was confirmed that there was no precipitation and the filterability was good.
• Comparative example 4 The afterimage of the liquid crystal aligning agent (AL-1) obtained in Comparative Example 1 was evaluated by long-term AC driving as described above. That is, a liquid crystal cell having the configuration of the FFS mode liquid crystal display device was prepared by using the liquid crystal aligning agent (AL-1) as described above, and afterimage evaluation by the long-term AC drive was performed on the FFS driven liquid crystal cell. did. As a result, the value of the angle ⁇ of this liquid crystal cell after long-term AC driving was 0.16 degrees.
• Example 3 An FFS-driven liquid crystal cell was produced in the same manner as in Comparative Example 4 except that the liquid crystal aligning agent (AL-4) obtained in Example 1 was used. Afterimage evaluation of the FFS-driving liquid crystal cell by long-term AC driving was performed, and as a result, the value of the angle ⁇ of the liquid crystal cell after long-term AC driving was 0.05 degrees.
• Example 4 The polymer two-component blend liquid crystal aligning agent (AL-5) obtained in Example 2 was filtered through a filter having a pore size of 1.0 ⁇ m, spin-coated on a glass substrate with a transparent electrode, and then on a hot plate at a temperature of 80 ° C. It was dried for 2 minutes. Then, after baking for 30 minutes in an IR oven at a temperature of 230 ° C., an imidized film having a film thickness of 100 nm was obtained. When the state of the fired film was confirmed, it was confirmed that the film was uniformly formed without unevenness or cissing.
• Table 1 summarizes the results of afterimage evaluation of the liquid crystal aligning agents of Comparative Examples 4 to 6 and Example 3 by long-term AC driving.

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