Classifications

• • 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
• • 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

Definitions

• the present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element obtained by using a diamine having a specific structure.
• a liquid crystal alignment film of a liquid crystal display element is mainly a liquid crystal alignment film obtained by applying a liquid crystal alignment agent (also referred to as a liquid crystal alignment treatment agent) containing a polyimide polymer to a substrate and baking it.
• the liquid crystal alignment film is used for the purpose of controlling the alignment state of the liquid crystal.
• the liquid crystal alignment film is used for the liquid crystal alignment film due to demands for suppressing a decrease in contrast of the liquid crystal display element and reducing an afterimage phenomenon.
• the important characteristics are that the voltage holding ratio is high, the residual charge is small when a DC voltage is applied, and / or the relaxation of the residual charge accumulated by the DC voltage is fast.
• liquid crystal display element is known as a display device that is lightweight, thin, and has low power consumption.
• liquid crystal display devices such as mobile phones, smart phones, and tablet devices, which have rapidly expanded their share, have made remarkable developments that require high display quality.
• the width of the sealing agent used for bonding the substrates of the liquid crystal display elements is made narrower than before, so-called narrow frame. Is required.
• the application position of the sealant used for manufacturing the liquid crystal display element is applied to the position in contact with the end of the liquid crystal alignment film or on the liquid crystal alignment film.
• polyimide since polyimide has no or few polar groups, there is a problem that a covalent bond is not formed between the sealing agent and the liquid crystal alignment film surface, resulting in insufficient adhesion between the substrates.
• the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal alignment film that does not cause display unevenness in the vicinity of the frame of the liquid crystal display element and has good adhesion to a sealant and a substrate.
• An object of the present invention is to provide a liquid crystal aligning agent used for forming the liquid crystal, and to provide a novel diamine having a specific structure used for producing the liquid crystal aligning agent.
• the present inventors have found that a polyimide precursor using a diamine having a specific structure and / or a liquid crystal aligning agent containing a polyimide obtained from the polyimide precursor is provided. It has been found that it has excellent characteristics, and the present invention has been completed.
• the present invention is a liquid crystal aligning agent containing a polyimide precursor obtained by reacting a diamine component and a tetracarboxylic acid component and / or a polyimide obtained from the polyimide precursor, wherein the diamine component is represented by the following formula (
• a liquid crystal aligning agent comprising a diamine having a structure represented by 1).
• R 1 and R 2 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a group represented by the following formula (2), at least one of which is represented by the formula (2).
• A is a divalent group which is a single bond or a hydrocarbon group having 1 to 4 carbon atoms.
• the liquid crystal alignment film formed using the polyimide precursor which uses the novel diamine which has the specific structure of this invention, and / or the polyimide obtained from this polyimide precursor is a sealing agent in a liquid crystal display element
• the adhesiveness to the substrate is high, the occurrence of display unevenness near the frame can be suppressed even under high temperature and high humidity conditions, and the frame area around the element can be reduced. Therefore, since the display area can be increased, the display area can be advantageously used for a small-sized and high-definition liquid crystal display element such as a mobile phone, a smart phone, and a tablet type element.
• the residual charge is quickly relaxed, there is an advantage that the afterimage phenomenon of the liquid crystal display element disappears in a short time.
• the polyimide precursor using a diamine having a specific structure of the present invention and / or a polyimide obtained from the polyimide precursor has a high solubility in a solvent, and thus has an advantage that a liquid crystal aligning agent having a high polymer concentration can be obtained. .
• the diamine contained in the diamine component used for obtaining the liquid crystal aligning agent of the present invention is a diamine having in its molecule a structure represented by the following formula (1).
• R 1 , R 2 and A are as defined above.
• at least one of R 1 and R 2 or both are preferably a group represented by the formula (2), and only one of R 1 and R 2 is preferred from the viewpoint of the orientation film strength during rubbing.
• A is preferably a single bond.
• the group of the formula (2) is a t-butoxycarbonyl group (also referred to as a Boc group in the present invention).
• the diamine having the structure represented by the above formula (1) in the molecule may be any diamine as long as the requirement is satisfied.
• a preferred example thereof is a diamine represented by the following formula [1].
• R 1 and R 2 are the same as those in the formula (1) including each preferable one.
• m and n are each independently an integer of 0 to 3, and are preferably 0 or 1 and more preferably 1 from the viewpoint of availability of raw materials.
• the amino group (—NH 2 ) in each benzene ring may be in any position of ortho, meta, or para with respect to the bonding position of the alkylene group. From the viewpoint of polymerization reactivity, the meta or para position is preferred, and the para position is more preferred.
• Examples of the diamine represented by the formula [1] preferably include the following compounds.
• Boc is a group represented by the following.
• the synthesis method of the diamine represented by Formula [1] is not specifically limited, As a general synthesis method, it can manufacture by reducing the dinitro compound X1 of the diamine X as shown below.
• R 1, R 2, m, n are each in the above formula (1) is the same as R 1, R 2, m, n.
• the reduction reaction includes a hydrogenation reaction in the presence of a catalyst, a reduction reaction performed in the presence of protons, a reduction reaction using formic acid as a hydrogen source, a reduction reaction using hydrazine as a hydrogen source, and the like. But you can. In view of the structure of the dinitro compound X1 and the reactivity of the reduction reaction, a hydrogenation reaction is preferred.
• the catalyst used for the reduction reaction is preferably an activated carbon-supported metal available as a commercial product, and examples thereof include palladium-activated carbon, platinum-activated carbon, rhodium-activated carbon and the like. Further, palladium catalyst, platinum oxide, Raney nickel or the like may not necessarily be an activated carbon supported metal catalyst. Palladium-activated carbon, which is generally widely used, is preferred because good results are obtained.
• the reaction may be carried out in the presence of activated carbon.
• the amount of the activated carbon to be used is not particularly limited, but is preferably 1 to 20% by mass, more preferably 5 to 10% by mass with respect to the dinitro compound X1.
• the reaction may be carried out under pressure. In this case, in order to avoid reduction of benzene nuclei, it is carried out in a pressure range up to 20 atm. The reaction is preferably carried out in the range up to 10 atm.
• aprotic polar organic solvents DMF (N, N-dimethylformamide), DMSO (dimethyl sulfoxide), DMAc (dimethylacetamide), NMP (N-methyl-2-pyrrolidone), etc.
• ethers Et 2 O (Diethyl ether), i-Pr 2 O (diiso-propyl ether), TBME (methyl tert-butyl ether), CPME (cyclopentyl methyl ether), THF (tetrahydrofuran), dioxane, etc.); aliphatic hydrocarbons (pentane, Hexane, heptane, petroleum ether, etc.); aromatic hydrocarbons (benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, nitrobenz
• solvents can be appropriately selected in consideration of the ease of reaction and the like, and can be used singly or in combination of two or more. If necessary, the solvent can be dried using a suitable dehydrating agent or desiccant and used as a non-aqueous solvent.
• the amount of solvent used is not particularly limited, but is 0.1 to 100 times by mass with respect to dinitro compound X1.
• the amount is preferably 0.5 to 30 times by mass, more preferably 1 to 10 times by mass.
• the reaction temperature is not particularly limited, but it is in the range from ⁇ 100 ° C. to the boiling point of the solvent used, preferably ⁇ 50 to 150 ° C.
• the reaction time is usually 0.05 to 350 hours, preferably 0.5 to 100 hours.
• the synthesis method of the dinitro compound X1 is not particularly limited, and can be synthesized by any method. As a specific example thereof, compound X2 and di-tert-butyl dicarbonate are reacted in a solvent, optionally in the presence of a base.
• a base in the reaction is not necessarily required, but when a base is used, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium bicarbonate, potassium bicarbonate, potassium phosphate, sodium carbonate, potassium carbonate, lithium carbonate, carbonate Inorganic bases such as cesium; amines such as trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamine, diisopropylethylamine, pyridine, dimethylaminopyridine, imidazole, quinoline, collidine; sodium hydride, potassium hydride, tert- Bases such as butoxy sodium and tert-butoxy potassium can be used.
• the solvent in such a reaction can be used as long as it does not react with each raw material, and is the same solvent as described in the synthesis of X1 from X above, aprotic polar organic solvent, ethers, fats Aromatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, lower fatty acid esters and the like can be used. These solvents can be appropriately selected in consideration of the ease of reaction and the like, and can be used singly or in combination of two or more. If necessary, the solvent can be dried using a suitable dehydrating agent or desiccant and used as a non-aqueous solvent. The amount of the solvent used is not particularly limited, but 0.1 to 100 times by mass of solvent may be used with respect to dinitro compound X2.
• the amount is preferably 0.5 to 30 times by mass, more preferably 1 to 10 times by mass.
• the reaction temperature is not particularly limited, but is in the range from ⁇ 100 ° C. to the boiling point of the solvent used, preferably in the range of ⁇ 50 to 150 ° C.
• the reaction time is usually 0.05 to 200 hours, preferably 0.5 to 100 hours.
• the dinitro compound X1 can be synthesized by reacting a carbonyl compound ( ⁇ ) with amine compounds X2 and X2 ′ provided with a Boc group in a solvent as described below. Specific examples thereof are shown in the following scheme.
• R 1 and R 2 each independently represent hydrogen or a Boc group.
• Y and Z are monovalent to divalent organic groups.
• Examples of the carbonyl compound ( ⁇ ) include phosgene, triphosgene, diphenyl carbonate, bis (nitrophenyl) carbonate, dimethyl carbonate, diethyl Examples include carbonate, ethylene carbonate, 1.1′-carbonylbis-1H-imidazole, methyl chloroformate, benzyl chloroformate, 4-nitrophenyl chloroformate, and the like.
• Carbon oxide may be used in place of the carbonyl compound ( ⁇ ).
• the above-described compound is an example and is not particularly limited.
• the nitro compounds X2 and X2 ′ may be the same.
• the nitro compound X2 is converted to a carbonyl compound ( ⁇ ),
• the nitro compound X2 ′ having a structure different from that of the nitro compound X2 may be added and reacted.
• the order of introducing the amine to which the Boc group is added is not particularly limited.
• Inorganic bases trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamine, diisopropylethylamine, amines such as pyridine, imidazole, quinoline, collidine; sodium hydride, potassium hydride, sodium tert-butoxy, tert-butoxy Bases such as potassium; and the like can be used.
• the solvent in such a reaction can be used as long as it does not react with each raw material, and is the same solvent as described in the synthesis of X1 from X above, aprotic polar organic solvent, ethers, fats Aromatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, lower fatty acid esters and the like can be used. These solvents can be appropriately selected in consideration of the ease of reaction and the like, and can be used singly or in combination of two or more. If necessary, the solvent can be dried using a suitable dehydrating agent or desiccant and used as a non-aqueous solvent.
• the amount of solvent used is not particularly limited, but 0.1 to 100 times by mass of solvent may be used with respect to nitro compound X2.
• the amount is preferably 0.5 to 30 times by mass, more preferably 1 to 10 times by mass.
• the reaction temperature is not particularly limited, but is in the range from ⁇ 100 ° C. to the boiling point of the solvent used, preferably in the range of ⁇ 50 to 150 ° C.
• the reaction time is usually 0.05 to 200 hours, preferably 0.5 to 100 hours.
• an asymmetric dinitro compound X1 having a different n it can be synthesized by reacting an isocyanate compound X4 and an amine compound X2 provided with a Boc group as described below.
• the following scheme is shown as a specific example.
• the amount of the amine compound X2 used may be 0.98 to 1.2 equivalent times the isocyanate compound X4. More preferably, it is 1.0 to 1.02 equivalent times.
• the reaction solvent is not particularly limited as long as it is inert to the reaction.
• hydrocarbons such as hexane, cyclohexane, benzene and toluene; halogens such as carbon tetrachloride, chloroform and 1,2-dichloroethane Hydrocarbons; ethers such as diethyl ether, diisopropyl ether, 1,4-dioxane and tetrahydrofuran; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; nitriles such as acetonitrile and propionitrile; ethyl acetate and ethyl propionate N-containing aprotic polar solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone; Dimethyl sul
• Sulfur aprotic polar solvent and the like are; pyridine, pyridine picoline, and the like. These solvents may be used alone or as a mixture of two or more thereof. Preferably it is toluene, acetonitrile, or ethyl acetate, More preferably, it is toluene or ethyl acetate.
• the amount of solvent used is not particularly limited, but the reaction may be carried out without using a solvent. When a solvent is used, it is 0.1 to 100 times by mass of isocyanate compound X4. Use solvent. The amount is preferably 0.5 to 30 times by mass, more preferably 1 to 10 times by mass.
• the reaction temperature is not particularly limited but is, for example, ⁇ 90 to 150 ° C., preferably ⁇ 30 to 100 ° C., and more preferably 0 to 80 ° C.
• the reaction time is usually 0.05 to 200 hours, preferably 0.5 to 100 hours.
• a catalyst may be added to shorten the reaction time.
• organotin compounds such as dibutyltin dilaurate, dioctyltin bis (isooctylthioglycolate), dibutyltinbis (isooctylthioglycolate), dibutyltin diacetate; triethylamine, trimethylamine, tripropylamine, tributylamine , Diisopropylethylamine, N, N-dimethylcyclohexylamine, pyridine, tetramethylbutanediamine, N-methylmorpholine, 1,4-diazabicyclo-2.2.2-octane, 1,8-diazabicyclo [5.4.0] Amines such as undecene, 1,5-diazabicyclo [4.3.0] nonene-5; organic sulfonic acids such as p-toluenesulfonic acid, methanesulfonic acid, fluo
• Inorganic acids Tiger butyl titanate, tetraethyl titanate, titanium compounds such as tetraisopropyl titanate; bismuth tris (2-ethylhexanoate) bismuth compounds such as; quaternary ammonium salts; and the like.
• These catalysts may be used alone or in combination of two or more. These catalysts are preferably liquid or soluble in the reaction solvent.
• the catalyst When the catalyst is added, the catalyst is used in an amount of 0.005 to 100 wt% with respect to the total amount (mass) of the isocyanate compound X4. Preferably it is 0.05 to 10 wt%, more preferably 0.1 to 5 wt%. If an organotin compound, a titanium compound, or a bismuth compound is used as the catalyst, the amount is preferably 0.005 to 0.1 wt%.
• the liquid crystal aligning agent of this invention is a polyimide precursor obtained by making the diamine component containing either of the diamine represented by said Formula [1], and a tetracarboxylic acid component react, and / or this polyimide. Contains polyimide obtained from the precursor.
• Tetracarboxylic acid component Preferred examples of the tetracarboxylic acid component are represented by any of the following formulas [8] to [10].
• a polyamic acid is obtained by reacting a tetracarboxylic acid anhydride represented by the formula [8] with a diamine.
• polyamic acid ester is obtained by making the tetracarboxylic acid diester dichloride represented by Formula [9] or the tetracarboxylic acid diester represented by Formula [10] react with diamine.
• a polyimide is compoundable by imidating this polyamic acid or polyamic acid ester.
• R 6 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
• the alkyl group include methyl group, ethyl group, propyl group, 2-propyl group, butyl group, t-butyl group and the like.
• the polyamic acid ester has a higher temperature at which imidization proceeds as the number of carbon atoms of its alkyl group increases.
• the alkyl group is preferably a methyl group or an ethyl group, particularly preferably a methyl group, from the viewpoint of ease of imidization by heat.
• X is preferably a tetravalent hydrocarbon group having a 4- to 6-membered alicyclic or aromatic ring structure.
• X include (X-1) to (X-46) shown below.
• Y is a divalent group consisting of hydrocarbon, preferably a group having a 6-membered alicyclic or aromatic ring structure. Specific preferred examples of Y include (Y-1) to (Y-97).
• Polyamic acid (hereinafter also referred to as polymer) can be synthesized by a polyaddition reaction of tetracarboxylic dianhydride and diamine (hereinafter also referred to as monomer). 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 organic solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, ⁇ -butyrolactone, etc. in view of the solubility of the monomer and the resulting polymer. You may mix and use.
• the concentration of the 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 is unlikely to occur and a high molecular weight product is easily obtained.
• the polyamic acid obtained as described above can be recovered by precipitating the polymer by pouring into the poor solvent while thoroughly stirring the reaction solution.
• cleaning with a poor solvent, and normal temperature or heat-drying can be obtained.
• a poor solvent is not specifically limited, Water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene etc. are mentioned.
• polyamic acid ester can be synthesized by any of the following methods (A) to (C).
• A) When synthesizing polyamic acid ester from polyamic acid Polyamic acid ester can be synthesized by esterifying polyamic acid obtained from tetracarboxylic dianhydride and diamine.
• the polyamic acid and the esterifying agent 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 4 hours.
• an organic solvent at ⁇ 20 to 150 ° C., preferably 0 to 50 ° C., for 30 minutes to 24 hours, preferably 1 to 4 hours.
• the esterifying agent is preferably one that can be easily removed by purification, and N, N-dimethylformamide dimethyl acetal, N, N-dimethylformamide diethyl acetal, N, N-dimethylformamide dipropyl acetal, N, N-dimethylformamide Dineopentyl butyl acetal, N, N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p -Tolyltriazene and the like.
• the addition amount of the esterifying agent is preferably 2 to 6 molar equivalents per 1 mol of the polyamic acid repeating unit.
• the organic solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, ⁇ -butyrolactone, etc. in view of polymer solubility, and these are used alone or in combination of two or more. May be.
• the concentration at the time of synthesis is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass because polymer precipitation is unlikely to occur and a high molecular weight body is easily obtained.
• tetracarboxylic acid diester dichloride and diamine are mixed 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 synthesized by reacting.
• a base pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable because the reaction proceeds gently.
• the addition amount of the base is preferably 2 to 4 times the molar amount of the tetracarboxylic acid diester dichloride from the viewpoint of easy removal and high molecular weight.
• the organic solvent used in the above reaction is preferably N-methyl-2-pyrrolidone, ⁇ -butyrolactone or the like in view of the solubility of the monomer and polymer, and these may be used alone or in combination.
• the concentration at the time of synthesis is preferably 1 to 30% by mass and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation is unlikely to occur and a high molecular weight product is easily obtained.
• the solvent used for the synthesis of polyamic acid ester is preferably dehydrated as much as possible, and the reaction is preferably prevented from mixing outside air in a nitrogen atmosphere.
• 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 15 It can synthesize
• Condensation agents include triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N′-carbonyldiimidazole, dimethoxy-1,3,5-triazinyl Methylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate diphenyl, and the like can be used.
• the addition amount of the condensing agent is preferably 2 to 3 times the molar amount of the tetracarboxylic
• tertiary amines such as pyridine and triethylamine can be used.
• the amount of the base added is preferably 2 to 4 times the amount of the diamine component from the viewpoint that it can be easily removed and a high molecular weight product can be easily obtained.
• the reaction proceeds efficiently by adding a Lewis acid as an additive.
• the Lewis acid lithium halides such as lithium chloride and lithium bromide are preferable.
• the addition amount of the Lewis acid is preferably 0 to 1.0 times the mole of the diamine component.
• the synthesis methods (A) and (B) are particularly preferable.
• the solution of the polyamic acid ester obtained as described above can be polymerized by pouring 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 polyamic acid ester powder.
• a poor solvent is not specifically limited, Water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene etc. are mentioned.
• the molecular weight of the polyimide precursor affects the viscosity of the varnish and the physical strength of the polyimide film.
• the weight average molecular weight is preferably 500,000 or less from the viewpoint of obtaining good application workability of the varnish and the coating film, and 2,000 or more is preferred from the viewpoint of obtaining a sufficiently strong polyimide film. More preferably, it is 2,000 to 300,000, and still more preferably 5,000 to 100,000.
• the molecular weight of the polyimide precursor can be controlled by adjusting the ratio of the diamine component used for the polymerization reaction and the tetracarboxylic acid derivative. As this ratio, a molar ratio of 1: 0.7 to 1.2 can be exemplified. The closer the molar ratio is to 1: 1, the higher the molecular weight of the resulting polyimide precursor.
• the polyimide of the present invention can be synthesized by imidizing the polyimide precursor.
• a simple and preferred method for synthesizing a polyimide from a polyimide precursor is chemical imidization in which a catalyst is added to the polyamic acid solution obtained by the reaction of a diamine component and tetracarboxylic dianhydride. This is preferable because the imidization reaction proceeds at a low temperature and the molecular weight of the polymer is hardly lowered during the imidization process.
• Chemical imidation can be performed by stirring the polymer to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride.
• a basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Among them, pyridine is preferable because it has a basicity suitable for advancing the reaction.
• the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among these, use of acetic anhydride is preferable because purification after completion of the reaction is easy.
• the temperature for carrying out the imidization reaction is ⁇ 20 to 200 ° C., preferably 0 to 180 ° C., and the reaction time is 1 to 100 hours, preferably 1 to 8 hours.
• the amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times the amount of the amic acid group, and the amount of the acid anhydride is 1 to 50 mol times of the amic acid group, preferably 3 to 30 mole times.
• the imidation rate of the resulting polymer can be controlled by adjusting the catalyst amount, temperature, reaction time, and the like. Since the added catalyst remains in the solution after the imidation reaction, the obtained imidized polymer is recovered by the means described below, redissolved in an organic solvent, and the liquid crystal alignment according to the present invention. It is preferable to use an agent.
• the polymer solution can be precipitated by pouring the polyimide solution obtained by the above method into a poor solvent while stirring well.
• the purified polyimide powder can be obtained by performing precipitation several times, washing with a poor solvent, and drying at room temperature or by heating.
• the poor solvent is not particularly limited as long as the polymer is precipitated, and examples thereof include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene.
• the liquid crystal aligning agent of the present invention is a varnish-like solution containing the polyimide precursor and / or polyimide (hereinafter also referred to as a polymer component) obtained as described above.
• the liquid crystal aligning agent of this invention may contain 2 or more types of polyimide precursors, 2 or more types of polyimides, and may contain both a polyimide precursor and a polyimide. Furthermore, the liquid crystal aligning agent may contain a polymer other than the polyimide precursor of the present invention or the polyimide of the present invention.
• the simplest structural example of the liquid crystal aligning agent of the present invention includes a composition comprising the above polyimide precursor and / or a polymer component of polyimide and an organic solvent for dissolving it.
• This composition may be a polyimide precursor or a reaction solution when the polyimide is synthesized, or may be a solution obtained by diluting the reaction solution with a solvent described later.
• the polyimide precursor or polyimide is recovered as a powder, it may be dissolved in an organic solvent to form a polymer solution.
• the concentration of the polymer component is preferably 10 to 30% by mass, particularly preferably 10 to 15% by mass. Moreover, you may heat when dissolving these.
• the heating temperature is preferably 20 to 150 ° C, particularly preferably 20 to 80 ° C.
• the organic solvent for dissolving the polyimide precursor or polyimide is not particularly limited as long as the polymer component is uniformly dissolved.
• the solvent component of the liquid crystal aligning agent of the present invention may contain, in addition to the organic solvent for dissolving the polymer component, a solvent for improving the coating film uniformity when the liquid crystal aligning agent is applied to the substrate.
• a solvent for improving the coating film uniformity when the liquid crystal aligning agent is applied to the substrate.
• a solvent having a surface tension lower than that of the organic solvent is generally used.
• ethyl cellosolve examples thereof include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2 -Propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, Examples include 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, and lactate isoamyl ester. It is. Two types of these solvents may be used in combination. Two types
• the polymer concentration in the liquid crystal aligning agent of the present invention can be appropriately changed depending on the thickness of the liquid crystal aligning film to be formed, but it is 1% by mass or more from the viewpoint of forming a uniform and defect-free coating film. From the viewpoint of storage stability of the solution, it is preferably 10% by mass or less. The polymer concentration is more preferably 2 to 8% by mass.
• the liquid crystal aligning agent of this invention may contain various additives, such as a silane coupling agent and a crosslinking agent.
• the silane coupling agent is added for the purpose of improving the adhesion between the substrate on which the liquid crystal alignment agent is formed and the liquid crystal alignment film formed there. Specific examples of the silane coupling agent include those described in International Publication No. WO2010 / 050523 (1st line to the last line of paragraph 0164 of International Application PCT / JP2009 / 068523).
• the amount of the silane coupling agent to be used is preferably 0.01 to 5% by mass with respect to the polymer component from the viewpoint that the unreacted agent does not adversely affect the liquid crystal orientation and the effect of adhesion appears. More preferably, the content is 1 to 1% by mass.
• Liquid crystal alignment film It is a coating film obtained by applying the liquid crystal aligning agent of this invention to a board
• 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, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used. It is preferable to use a substrate on which the ITO electrode or the like is formed from the viewpoint of simplification of the process.
• an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and a material that reflects light such as aluminum can be used for the electrode.
• Examples of the method for applying the liquid crystal aligning agent include a spin coating method, a printing method, and an ink jet method.
• Arbitrary temperature and time can be selected for the drying and baking steps after applying the liquid crystal aligning agent.
• it is dried at 50 to 120 ° C. for 1 to 10 minutes, and then baked at 150 to 300 ° C. for 5 to 120 minutes.
• the thickness of the coating film after firing is not particularly limited, but if it is too thin, the reliability of the liquid crystal display element may be lowered, so it is 5 to 300 nm, preferably 10 to 200 nm.
• the fired coating film is rubbed or photo-aligned.
• a liquid crystal cell is prepared by a known method to obtain a liquid crystal display element.
• the method for producing the liquid crystal cell is not particularly limited.
• a pair of substrates on which the liquid crystal alignment film is formed is preferably 1 to 30 ⁇ m, more preferably 2 to 2 with the liquid crystal alignment film surface inside.
• a method is generally employed in which a 10 ⁇ m spacer is placed and then the periphery is fixed with a sealant, liquid crystal is injected, and sealing is performed.
• the method for enclosing the liquid crystal is not particularly limited, and examples thereof include a vacuum method for injecting liquid crystal after reducing the pressure inside the produced liquid crystal cell, and a dropping method for sealing after dropping the liquid crystal.
• a liquid crystal alignment agent is applied on two substrates to form a liquid crystal alignment layer, and the two substrates are arranged so that the liquid crystal alignment layers face each other.
• a liquid crystal layer is sandwiched between sheets of a substrate, and an ultraviolet ray is irradiated while applying an electric field to the liquid crystal layer.
• the substrate used is not particularly limited as long as it is a highly transparent substrate, but is usually a substrate on which a transparent electrode for driving liquid crystal is formed on a substrate, and a substrate on which an electrode pattern or a protrusion pattern is provided. May be used.
• the liquid crystal alignment layer is a resin film for aligning liquid crystals, and the method for forming a liquid crystal alignment layer on a substrate using a liquid crystal aligning agent is the same as the coating method described in the liquid crystal alignment film. A later baking method can be applied.
• the step of irradiating ultraviolet rays while applying an electric field to the liquid crystal layer applies, for example, an electric field to the liquid crystal layer by applying a voltage between the electrodes installed on the substrate, and irradiates the ultraviolet rays while maintaining the electric field.
• the voltage applied between the electrodes is, for example, 5 to 30 Vp-p, and preferably 5 to 20 Vp-p.
• the amount of ultraviolet irradiation is, for example, 1 to 60 J, preferably 40 J or less. It is preferable that the amount of ultraviolet rays is small because it is possible to suppress a decrease in reliability that causes damage to the members constituting the liquid crystal display element, and the production efficiency is increased by selecting the ultraviolet irradiation time.
• a mixture of A1-1 (100 g, 218 mmol), 5 mass% Pd / C (50% water-containing type), and toluene (1200 ml) was stirred at 60 ° C. for 5 hours in the presence of hydrogen. After completion of the reaction, the catalyst was filtered, and then the solution was cooled to 5 ° C. and further stirred for 1 hour. The precipitated crystals were filtered under reduced pressure, washed with toluene (200 g), and then dried to obtain powder crystals A1 (yield 70 g, yield 80%).
• Example 1 To 10.0 g of the polyamic acid solution obtained in Synthesis Example 1, 5.65 g of NMP, 1.0 g of NMP solution containing 1.0% by mass of 3-glycidoxypropyltriethoxysilane, and 5.55 g of BCS were added. In addition, a liquid crystal aligning agent (A-1) having a concentration of 4.5% by mass was obtained. In this liquid crystal aligning agent (A-1), no abnormality such as turbidity or generation of precipitates was observed, and it was confirmed that the liquid crystal aligning agent (A-1) was a uniform solution.
• Example 2 To 10.0 g of the polyamic acid solution obtained in Synthesis Example 2, 5.65 g of NMP, 1.0 g of NMP solution containing 1.0% by mass of 3-glycidoxypropyltriethoxysilane, and 5.55 g of BCS were added. In addition, a liquid crystal aligning agent (A-2) having a concentration of 4.5% by mass was obtained. In this liquid crystal aligning agent (A-2), no abnormality such as turbidity or precipitation was observed, and it was confirmed that the liquid crystal aligning agent (A-2) was a uniform solution.
• ⁇ Preparation of adhesive evaluation sample> The liquid crystal aligning agent is filtered through a 1.0 ⁇ m filter, spin-coated on a glass substrate with a transparent electrode, dried on an 80 ° C. hot plate for 2 minutes, and then baked at 230 ° C. for 20 minutes. A 100 nm coating was obtained. Two substrates thus obtained were prepared, and a bead spacer having a diameter of 4 ⁇ m was sprayed on the liquid crystal alignment film surface of one of the substrates, and then a sealant (XN-1500T manufactured by Kyoritsu Chemical Co., Ltd.) was applied. It was applied in the form of dots.
• bonding was performed so that the liquid crystal alignment film surface of the other substrate was inward, the overlapping width of the substrates was 1 cm, and the sealing agent was positioned at the center of the overlapping portion of the substrates. At that time, the amount of the sealant dropped was adjusted so that the diameter of the sealant after bonding was about 3 mm.
• the two bonded substrates were fixed with a clip and then thermally cured at 120 ° C. for 1 hour to prepare a sample for evaluating adhesiveness.
• the liquid crystal aligning agent is filtered through a 1.0 ⁇ m filter, spin-coated on a glass substrate with a transparent electrode, dried on an 80 ° C. hot plate for 2 minutes, and then baked at 230 ° C. for 20 minutes. A 100 nm coating was obtained.
• the imidized polymer film was rubbed with a rayon cloth (roll diameter: 120 mm, rotation speed: 1000 rpm, moving speed: 20 mm / sec, pushing amount: 0.4 mm), and then subjected to ultrasonic irradiation for 1 minute in pure water at 80 ° C. For 10 minutes.
• Two substrates with a liquid crystal alignment film obtained in this way were prepared, and after placing a 4 ⁇ m spacer on the liquid crystal alignment film surface of one substrate, the rubbing directions of the two substrates were combined so that they were antiparallel.
• the periphery was sealed leaving the liquid crystal injection port, and an empty cell having a cell gap of 4 ⁇ m was produced.
• Liquid crystal (MLC-2041, manufactured by Merck & Co., Inc.) was vacuum-injected into this cell at room temperature, and the inlet was sealed to obtain an anti-parallel liquid crystal cell.
• a liquid crystal cell having a configuration of an FFS (Fringe Field Switching) liquid crystal display element was manufactured.
• a substrate with electrodes was prepared.
• the substrate is a glass substrate having a size of 30 mm ⁇ 35 mm and a thickness of 0.7 mm.
• an IZO (Indium Tin Oxide) having a solid pattern constituting a counter electrode as a first layer is provided.
• An electrode was formed.
• a SiN (silicon nitride) film formed by a CVD (Chemical Vapor Deposition) method was formed as a second layer on the counter electrode of the first layer.
• the second layer SiN film has a thickness of 500 nm and functions as an interlayer insulating film.
• a comb-like pixel electrode formed by patterning an IZO film as the third layer is arranged to form two pixels, a first pixel and a second pixel. It was. The size of each pixel is 10 mm long and about 5 mm wide.
• the first-layer counter electrode and the third-layer pixel electrode were electrically insulated by the action of the second-layer SiN film.
• the pixel electrode of the third layer has a comb-like shape configured by arranging a plurality of dog-shaped electrode elements whose central portion is bent.
• the width of each electrode element in the short direction was 3 ⁇ m, and the distance between the electrode elements was 6 ⁇ m. Since the pixel electrode forming each pixel is formed by arranging a plurality of bent-shaped electrode elements in the central portion, the shape of each pixel is not rectangular, but in the central portion like the electrode elements. It had a shape that bends and resembles a bold-faced koji.
• Each pixel is vertically divided with the central bent portion as a boundary, and has a first region on the upper side of the bent portion and a second region on the lower side.
• the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, when the rubbing direction of the liquid crystal alignment film to be described later is used as a reference, in the first region of the pixel, the electrode element of the pixel electrode is formed to form an angle of + 10 ° (clockwise), and in the second region of the pixel The electrode elements of the pixel electrode are formed at an angle of ⁇ 10 ° (clockwise). That is, in the first region and the second region of each pixel, the directions of the rotation operation (in-plane switching) of the liquid crystal induced by the voltage application between the pixel electrode and the counter electrode are mutually in the substrate plane. It is comprised so that it may become a reverse direction.
• the obtained liquid crystal aligning agent was filtered through a 1.0 ⁇ m filter, and then applied to the prepared substrate with electrodes by spin coating. After drying for 120 seconds on a hot plate at 80 ° C., baking was performed in a far-infrared oven at 230 ° C. for 20 minutes to obtain a polyimide film having a thickness of 60 nm.
• This polyimide film is rubbed with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 500 rpm, moving speed: 30 mm / sec, indentation length: 0.3 mm, rubbing direction: inclined by 10 ° with respect to the third layer IZO comb-teeth electrode. Then, the substrate was washed by irradiating with ultrasonic water for 1 minute with pure water to remove water droplets by air blow, and then dried at 80 ° C. for 15 minutes to obtain a substrate with a liquid crystal alignment film.
• a polyimide film is formed on a glass substrate having a columnar spacer with a height of 4 ⁇ m on which the ITO electrode is formed on the back surface, and an alignment treatment is performed in the same procedure as above.
• the obtained substrate with a liquid crystal alignment film was obtained.
• One set of these two substrates with a liquid crystal alignment film is printed, and the sealant is printed on the substrate leaving the liquid crystal injection port.
• the other substrate has the liquid crystal alignment film surface facing and the rubbing direction is antiparallel. Then, the sealing agent was cured to produce an empty cell having a cell gap of 4 ⁇ m.
• Liquid crystal MLC-2041 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 110 ° C. for 30 minutes and left at 23 ° C. overnight before being used for each evaluation.
• the liquid crystal cell (usually liquid crystal is used) is placed between two polarizing plates arranged so that the polarization axes are orthogonal to each other, and the pixel electrode and the counter electrode are short-circuited to have the same potential.
• the angle of the liquid crystal cell was adjusted so that the brightness of the LED backlight transmitted light measured on the two polarizing plates was minimized by irradiating the LED backlight from the bottom of the polarizing plate.
• the VT characteristics voltage-transmittance characteristics
• an AC voltage with a relative transmittance of 23% is measured. Calculated. Since this AC voltage corresponds to a region where the change in luminance with respect to the voltage is large, it is convenient for evaluating the residual charge via the luminance.
• the liquid crystal aligning agent of the present invention can form a liquid crystal aligning film having good adhesion to a sealing agent or a substrate in an element, has little display unevenness in the vicinity of the frame, and can secure a large display area. Especially, it is used for small high-definition liquid crystal display elements and the like such as phones and tablet terminals.

Landscapes

• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Nonlinear Science (AREA)
• Mathematical Physics (AREA)
• Crystallography & Structural Chemistry (AREA)
• Spectroscopy & Molecular Physics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Liquid Crystal (AREA)
• Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=55533266

Family Applications (1)

Country Status (5)

Cited By (2)

Families Citing this family (3)

Citations (2)

Family Cites Families (10)

• 2015
  • 2015-09-16 CN CN201580062474.1A patent/CN107003568B/zh active Active
  • 2015-09-16 JP JP2016548915A patent/JP6607191B2/ja active Active
  • 2015-09-16 KR KR1020177010264A patent/KR102367765B1/ko active IP Right Grant
  • 2015-09-16 WO PCT/JP2015/076339 patent/WO2016043230A1/ja active Application Filing
  • 2015-09-18 TW TW104130963A patent/TWI689551B/zh active
• 2019
  • 2019-09-05 JP JP2019162345A patent/JP6798592B2/ja active Active

Patent Citations (2)

Also Published As

Similar Documents

Legal Events