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
• • 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 novel diamine, a polymer used for a liquid crystal display element, a liquid crystal alignment agent and a liquid crystal alignment film, and a liquid crystal display element.
• Liquid crystal display elements are currently widely used as display devices that are thin and lightweight.
• the display characteristics of liquid crystal display elements are known to be greatly influenced by the orientation of the liquid crystal, the size of the pretilt angle of the liquid crystal, the stability of the pretilt angle, the electrical characteristics, etc.
• the display characteristics of such liquid crystal display elements In order to improve the ratio, not only the liquid crystal material to be used, but also a liquid crystal alignment film that is in direct contact with the liquid crystal and determines the alignment state is important.
• the liquid crystal alignment film mainly uses a resin solution of polyamic acid or polyimide as a liquid crystal alignment agent, and after applying them to the substrate, firing is performed, and the surface of the coating film is subjected to pressure by rayon or nylon cloth. It is formed by performing a so-called rubbing process.
• the method of obtaining a liquid crystal alignment film from polyimide or its precursor polyamic acid can produce a coating film excellent in heat resistance and solvent resistance by a simple process of applying and baking a resin solution, and by rubbing Since the liquid crystal can be easily aligned, it has been widely spread industrially and has been up to now.
• Patent Document 1 proposes to use a polyimide resin having a specific repeating unit in order to obtain a high voltage holding ratio.
• Patent Document 2 proposes to shorten the time until the afterimage is erased by using soluble polyimide having a nitrogen atom in addition to the imide group for the afterimage phenomenon.
• an object of the present invention is to provide a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element in which accumulated charge is quickly relaxed and transparency, solubility, and orientation are improved.
• the liquid crystal aligning agent of the present invention that achieves the above object includes a polymer obtained from a diamine component containing a diamine having a structure represented by the following formula [1], and an organic solvent.
• Y 1 represents an S atom or an O atom
• * represents a site bonded to another group.
• any hydrogen atom of the benzene ring is substituted with a monovalent organic group. May be.
• the polymer is at least one selected from the group consisting of a polyimide precursor which is a polycondensate of a diamine having a structure represented by the formula [1] and a tetracarboxylic dianhydride and a polyimide which is an imidized product thereof.
• the polymer is preferably.
• diamine is represented by the following formula [2].
• Y 1 is the same as in the above formula [1]
• R 2 each independently represents a single bond or the structure of the following formula [3], and n is 1 to 3 Represents an integer, and any hydrogen atom in the benzene ring may be substituted with a monovalent organic group.
• R 3 represents a single bond, —O—, —COO—, —OCO—, — (CH 2 ) 1 —, —O (CH 2 ) m O—, —CONH—, and — Represents a divalent organic group selected from NHCO- (l, m represents an integer of 1 to 5), * 1 represents a site bonded to a benzene ring in the formula [2], and * 2 represents a formula [2 ] Represents the site
• the said polymer is at least 1 type selected from the polyimide which is a polyimide precursor containing the structural unit represented by following formula [4], and its imide compound.
• X 1 is a tetravalent organic group derived from a tetracarboxylic acid derivative
• W 1 is a divalent derived from a diamine having a structure represented by Formula [2] or Formula [3].
• R 4 and R 5 represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms
• a 1 and A 2 each independently represent a hydrogen atom or a carbon atom having 1 to 5 carbon atoms. Represents an alkyl group, an alkenyl group having 2 to 5 carbon atoms, or an alkynyl group having 2 to 5 carbon atoms.
• the liquid crystal alignment film of the present invention that achieves the above object is obtained from the above liquid crystal aligning agent.
• the liquid crystal display element of the present invention that achieves the above object is characterized by comprising the above liquid crystal alignment film.
• liquid crystal aligning agent a liquid crystal alignment film, and a liquid crystal display element, in which stored charge is quickly relaxed and transparency, solubility, and orientation are improved.
• the liquid crystal aligning agent of this invention contains the polymer obtained from the diamine component containing the diamine which has a structure represented by following formula [1], and an organic solvent, First, diamine is demonstrated.
• Y 1 represents an S atom or an O atom
• * represents a site bonded to another group.
• any hydrogen atom of the benzene ring is substituted with a monovalent organic group. May be.
• the monovalent organic group includes a hydrocarbon group; a hydrocarbon group containing a hydroxyl group, a carboxyl group, a hydroxyl group, a thiol group, or a carboxyl group; a bonding group such as an ether bond, an ester bond, or an amide bond.
• a hydrocarbon group linked by: a hydrocarbon group containing a silicon atom; a halogenated hydrocarbon group; an amino group; an inert group in which the amino group is protected by a carbamate-based protecting group such as a t-butoxycarbonyl group, etc. Can be mentioned.
• the hydrocarbon group may be a straight chain, branched chain or cyclic chain, and may be a saturated hydrocarbon or an unsaturated hydrocarbon.
• some of the hydrogen atoms of the hydrocarbon group may be replaced by carboxyl groups, hydroxyl groups, thiol groups, silicon atoms, halogen atoms, etc., and are linked by a linking group such as an ether bond, an ester bond, or an amide bond. It may be.
• the alkylene group having 1 to 3 carbon atoms may be a straight chain, a branched chain or a cyclic chain.
• a monovalent organic group or an alkylene group having 1 to 3 carbon atoms can be variously selected depending on applications.
• the bonding position of the benzene ring to the five-membered ring is a carbon atom adjacent to Y 1 on the five-membered ring as shown in the following formula [1-1] from the viewpoint of charge transfer.
• the bonding position of the benzene ring to the five-membered ring is a carbon atom adjacent to Y 1 on the five-membered ring as shown in the following formula [1-1] from the viewpoint of charge transfer.
• the specific diamine can be represented by, for example, the following formula [1-2], and is particularly preferably a diamine represented by the following formula [1-3], and further represented by the formula [1-4]. Diamine is more preferred.
• Y 1 is the same as in the case of the formula [1].
• Q 1 and Q 2 are each independently a single bond or a divalent group. It is an organic group, that is, Q 1 and Q 2 may have different structures. Further, the two Q 2 in the formula [1-4] may have different structures. Furthermore, any hydrogen atom of the benzene ring may be substituted with a monovalent organic group as in the case of the above formula [1].
• Preferred examples of the specific diamine include diamines represented by the following formula [2], and more preferred are diamines represented by the formula [2-1].
• Y 1 in the above formula [2] and formula [2-1] is the same as that in the formula [1].
• Two R 2 s each independently represent a single bond or a structure of the following formula [3].
• any hydrogen atom of the benzene ring may be substituted with a monovalent organic group.
• R 3 represents a single bond, —O—, —COO—, —OCO—, — (CH 2 ) 1 —, —O (CH 2 ) m O—, —CONH—, and — It represents a divalent organic group selected from the group consisting of NHCO—, wherein l and m each represents an integer of 1 to 5.
• R 3 is preferably a single bond, —O—, —COO—, —OCO—, —CONH—, or —NHCO— from the viewpoint of relaxation of accumulated charge.
• * 1 represents a site bonded to the benzene ring in the formula [2]
• * 2 represents a site bonded to the amino group in the formula [2].
• N in the above formula [2] and formula [2-1] represents an integer of 1 to 3. Preferably it is 1 or 2.
• diamine represented by the formula [2] examples include diamines represented by the following formulas [4-1-1] to [4-1-12], but are not limited thereto.
• [4-1-1], [4-1-2], and [4-1-4] to [4-1-12] are preferable from the viewpoint of relaxation of accumulated charge and orientation.
• -1-1], [4-1-2], and [4-1-8] to [4-1-12] are particularly preferable.
• the diamine of the present invention can be obtained by reducing a dinitro compound and converting a nitro group to an amino group as shown in the following reaction formula.
• a diamine in which the hydrogen atom of the benzene ring and the saturated hydrocarbon portion is not substituted with a halogen atom such as a fluorine atom or a monovalent organic group other than an amino group is described as an example.
• the method for reducing the dinitro compound is not particularly limited, and palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon, etc. are used as a catalyst, such as ethyl acetate, toluene, tetrahydrofuran, dioxane, alcohols, etc.
• a catalyst such as ethyl acetate, toluene, tetrahydrofuran, dioxane, alcohols, etc.
• Examples of the method include reduction with hydrogen gas, hydrazine, hydrogen chloride or the like in a solvent. You may carry out under pressure using an autoclave etc. as needed.
• an unsaturated bond site is included in the structure of the substituent that replaces the hydrogen atom of the benzene ring or saturated hydrocarbon portion, using palladium carbon, platinum carbon, or the like, the unsaturated bond site is reduced, Since there is a possibility of becoming a saturated bond, reducing conditions using a transition metal such as reduced iron, tin, or tin chloride as a catalyst are preferable.
• the above reaction can be performed in the presence of a base.
• the base to be used is not particularly limited as long as it can be synthesized, but inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide, sodium hydride, pyridine, dimethylaminopyridine And organic bases such as trimethylamine, triethylamine, and tributylamine.
• a palladium catalyst such as dibenzylideneacetone palladium or diphenylphosphinoferrocene palladium, a copper catalyst, or the like is used in combination, the yield can be improved.
• the diamine of the present invention thus obtained can be used as a raw material for polyimide precursors such as polyamic acid and polyamic acid ester, polyimide, polyurea, polyamide and the like (collectively referred to as “polymer”).
• polymer can be used, for example, as a liquid crystal aligning agent by being dissolved in a predetermined organic solvent, but is not limited to its use.
• the polymer containing the diamine represented by the formula [1] in the structure will be described.
• the polymer of the present invention is obtained by using the above-described diamine of the present invention or a derivative thereof (described later), and has a structure represented by the following formula [1] derived from the diamine component.
• Y 1 represents an S atom or an O atom
• * represents a site bonded to another group.
• any hydrogen atom of the benzene ring is substituted with a monovalent organic group. May be.
• Y 1 is the same as in Formula [1] above, R 2 independently represents a single bond or the structure of Formula [3] below, and n is from 1 to Represents an integer of 3, and * 2 represents a site bonded to another group, and any hydrogen atom of the benzene ring may be substituted with a monovalent organic group.
• R 3 represents a single bond, —O—, —COO—, —OCO—, — (CH 2 ) 1 —, —O (CH 2 ) m O—, —CONH—, and —
• * 1 represents a site bonded to the benzene ring in formula [2]
• * 2 represents another group Represents the site that binds to
• the derivative of the diamine of the present invention a structure in which two or more of the above structures are connected, or a structure in which the above structures are connected through —O—, —S—, —COO— or —OCO—.
• the structure derived from the diamine component may include a structure derived from other diamine (described later) in addition to the structure of the formula [2].
• examples of the monovalent organic group and the alkylene group having 1 to 3 carbon atoms in the formula [2] include those similar to the formula [1].
• the polymer of the present invention is at least one selected from a polyimide precursor containing a structural unit represented by the following formula [4] and a polyimide that is an imide compound thereof, from the viewpoint of use as a liquid crystal aligning agent. It is preferable.
• X 1 is a tetravalent organic group derived from a tetracarboxylic acid derivative
• W 1 is a divalent derived from a diamine having a structure represented by Formula [2] or Formula [3].
• R 4 and R 5 represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms
• a 1 and A 2 each independently represent a hydrogen atom or a carbon atom having 1 to 5 carbon atoms. Represents an alkyl group, an alkenyl group having 2 to 5 carbon atoms, or an alkynyl group having 2 to 5 carbon atoms.
• examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group.
• alkenyl group having 2 to 5 carbon atoms examples include vinyl group, allyl group, 1-propenyl group, 1-butenyl group, 2 -Butenyl group, 3-butenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group and the like.
• alkynyl group having 2 to 5 carbon atoms examples include ethynyl group, Examples include 1-propynyl group, 2-propynyl (propargyl) group, 3-butynyl group, pentynyl group and the like.
• R 1 and R 2 are preferably a hydrogen atom, a methyl group or an ethyl group, more preferably a hydrogen atom or a methyl group, and liquid crystal orientation.
• a 1 and A 2 are preferably a hydrogen atom or a methyl group.
• X 1 is not particularly limited as long as it is a tetravalent organic group derived from a tetracarboxylic acid derivative. Moreover, X 1 is coatability solubility and liquid crystal alignment agent in the solvent of the polymer liquid crystal orientation in the case where the liquid crystal alignment film, the voltage holding ratio, such stored charge, the degree of properties required Depending on the selection, one type may be used in the same polymer, or two or more types may be mixed.
• X 1 is not only a tetracarboxylic dianhydride but also a tetracarboxylic acid, tetracarboxylic acid dihalide compound, tetracarboxylic acid dialkyl ester compound or tetracarboxylic acid dialkyl ester dihalide compound which is a tetracarboxylic acid derivative thereof. it can.
• the tetracarboxylic dianhydride or derivative thereof it is more preferable to use at least one selected from tetracarboxylic dianhydrides represented by the following formula [5] or derivatives thereof.
• V 1 is a tetravalent organic group having an alicyclic structure, and the structure is not particularly limited. Specific examples include the following formula [V 1 -1] to formula [V 1 -44].
• R 7 to R 27 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or 2 to 2 carbon atoms.
• R 7 to R 27 are preferably a hydrogen atom, a halogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group.
• Specific structures of the formula [V 1 -1] include structures represented by the following formulas [V 1 -1-1] to [V 1 -1-6].
• a structure represented by the following formula [V 1 -1-1] is particularly preferable from the viewpoint of liquid crystal alignment and photoreaction sensitivity.
• W 1 is not particularly limited as long as W 1 is a divalent organic group derived from a diamine having a structure represented by formula [1] or formula [2]. More than one type may be mixed.
• W 1 corresponds to the structure of the diamine component used in the present invention and has a specific structure having a structure represented by the formula [1] (for example, the following formula [W 1 -1] to formula [W 1 -12]. At least one structure selected from the group consisting of compounds represented by
• W 1 it is not always necessary that all of W 1 have a structure corresponding to the diamine.
• a part of W 1 may contain a structure corresponding to a diamine other than the diamine (other diamine).
• the structure corresponding to the other diamine (hereinafter referred to as “structure W 2 ”) can be generalized as represented by the following formula [6]. As the A 1 and A 2 in the formula [6] are the same as those for the formula [4].
• W 2 represented by the formula [6] is illustrated as represented by the following formula [W 2 -1] to formula [W 2 -173].
• the Boc group in the formula [W 2 -168], the formula [W 2 -169], the formula [W 2 -172] and the formula [W 2 -173] is a tert-butoxycarbonyl group represented by the following formula. Represents.
• the tert-butoxycarbonyl group is also referred to as a Boc group.
• the structural unit represented by the formula [4] It is preferable that it is 10 mol% or more with respect to the sum total of [6], More preferably, it is 20 mol% or more, Most preferably, it is 30 mol% or more.
• the molecular weight of the polyimide precursor or polyimide, which is a polymer contained in the liquid crystal aligning agent of the present invention, is the coating film (liquid crystal aligning film) when the liquid crystal aligning film is obtained from the liquid crystal aligning agent containing the polymer.
• the weight average molecular weight measured by GPC (Gel Permeation Chromatography) method is preferably 2,000 to 500,000 in consideration of the strength of the film, the workability during coating film formation, and the uniformity of the coating film. More preferably from 10,000 to 300,000, and even more preferably from 10,000 to 100,000.
• the polymer containing the structural unit represented by the formula [4] is a polyamic acid that is a polyimide precursor
• the polymer includes a tetracarboxylic dianhydride that is a tetracarboxylic acid derivative and a diamine component.
• a known synthesis method can be used.
• the synthesis method is a method in which a tetracarboxylic dianhydride and a diamine component are reacted in an organic solvent. Such a method is advantageous in that it proceeds relatively easily in an organic solvent and no by-products are generated.
• the organic solvent used in the above reaction is not particularly limited as long as the produced polyamic acid (polymer) can be dissolved.
• N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2 -Pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, ⁇ -butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, Methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve
• the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride is used as it is or in an organic solvent.
• tetracarboxylic dianhydride or diamine component when they are composed of a plurality of types of compounds, they may be reacted in a premixed state, may be individually reacted sequentially, or may be further reacted individually. May be mixed to form a high molecular weight product.
• the polycondensation temperature can be selected from -20 ° C to 150 ° C, but it is preferably in the range of -5 ° C to 100 ° C.
• the polycondensation reaction can be carried out at any concentration, but if the concentration is too low, it will be difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution will become too high and uniform stirring will occur. Therefore, the total concentration of the tetracarboxylic dianhydride and the diamine component in the reaction solution is preferably 1% by mass to 50% by mass, more preferably 5% by mass to 30% by mass.
• the initial stage of the reaction may be performed at a high concentration, and then an organic solvent may be added.
• the ratio of the total number of moles of tetracarboxylic dianhydride and the total number of moles of diamine component is 0. It is preferably 8 to 1.2. Similar to the normal polycondensation reaction, the closer the molar ratio is to 1.0, the higher the molecular weight of the polyamic acid produced.
• the polymer containing the structural unit represented by the formula [4] is a polyamic acid ester, a reaction between tetracarboxylic acid diester dichloride and a diamine component, or a suitable condensing agent for converting the tetracarboxylic acid diester and diamine component. It can obtain by making it react in presence of a base. Alternatively, it can also be obtained by previously synthesizing a polyamic acid by the above method and esterifying the carboxylic acid in the amic acid using a polymer reaction.
• tetracarboxylic acid diester dichloride and diamine are -20 ° C to 150 ° C, preferably 0 ° C to 50 ° C in the presence of a base and an organic solvent, for 30 minutes to 24 hours, preferably 1
• a polyamic acid ester can be synthesized.
• 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 mol of tetracarboxylic acid diester dichloride from the viewpoint of easy removal and high molecular weight.
• 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 amount of Lewis acid added is preferably 0.1 to 1.0 times the molar amount of the diamine or tetracarboxylic acid diester to be reacted.
• the solvent used in the above reaction can be the same solvent as that used in the synthesis of the polyamic acid shown above, but N-methyl-2-pyrrolidone, ⁇ -Butyrolactone is preferred, and these may be used alone or in combination of two or more.
• the concentration at the time of synthesis is such that in the reaction solution of a tetracarboxylic acid derivative such as tetracarboxylic acid diester dichloride or tetracarboxylic acid diester and a diamine component, from the viewpoint that polymer precipitation is difficult to occur and a high molecular weight product is easily obtained.
• the total concentration is preferably 1% by mass to 30% by mass, and more preferably 5% by mass to 20% by mass.
• the solvent used for the synthesis of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent mixing of outside air in a nitrogen atmosphere.
• the polymer containing the structural unit represented by the formula [4] is a polyimide
• the polymer has a divalent group represented by the formula [1] or the formula [2] in the main chain, and It can be obtained by dehydrating and ring-closing polyamic acid.
• the dehydration cyclization rate (imidization rate) of the amic acid group is not necessarily 100%, and can be arbitrarily adjusted according to the application and purpose.
• Examples of the method for imidizing polyamic acid include thermal imidization in which a polyamic acid solution is heated as it is, and catalytic imidization in which a catalyst is added to a polyamic acid solution.
• the temperature at which the polyamic acid is thermally imidized in the solution is 100 ° C. to 400 ° C., preferably 120 ° C. to 250 ° C., and is preferably carried out while removing water generated by the imidization reaction from the outside of the system.
• the catalytic imidation of polyamic acid can be performed by adding a basic catalyst and an acid anhydride to a polyamic acid solution and stirring at -20 ° C to 250 ° C, preferably 0 ° C to 180 ° C.
• the amount of the basic catalyst is 0.5 mol times to 30 mol times, preferably 2 mol times to 20 mol times of the amic acid groups, and the amount of the acid anhydride is 1 mol times to 50 mol times of the amic acid groups, The amount is preferably 3 mole times to 30 mole times.
• the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and the like.
• pyridine is preferable because it has an appropriate basicity for proceeding with the reaction.
• the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like.
• use of acetic anhydride is preferable because purification after completion of the reaction is facilitated.
• the imidization rate by catalytic imidation can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.
• polyimide can also be obtained by heating a polyamic acid ester at a high temperature to promote dealcoholization and ring closure.
• the reaction solution is poured into a poor solvent and precipitated. That's fine.
• the poor solvent used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water.
• the polyimide precursor and polyimide which have been put into a poor solvent and precipitated are collected by filtration, they can be dried at normal temperature or under reduced pressure at room temperature or by heating.
• the impurities in the polymer can be reduced by repeating the steps of re-dissolving the precipitated and recovered polyimide precursor and polyimide in an organic solvent and repeating the reprecipitation and recovery 2 to 10 times.
• the poor solvent at this time include alcohols, ketones, hydrocarbons and the like, and it is preferable to use three or more kinds of poor solvents selected from these because purification efficiency is further improved.
• the polymer of the present invention thus obtained can be dissolved in a predetermined organic solvent and used as a liquid crystal aligning agent.
• This liquid crystal aligning agent is used for the liquid crystal aligning film which controls the orientation of the liquid crystal molecule of a liquid crystal layer in a liquid crystal display element.
• the liquid crystal aligning agent containing the polymer of this invention is demonstrated.
• the liquid crystal aligning agent of this invention contains the polymer obtained from the diamine component containing the diamine which has a structure represented by Formula [1] derived from the said diamine component. Moreover, it is preferable that this liquid crystal aligning agent contains the polymer which has a structure represented by Formula [2] derived from the said diamine component. Moreover, it is preferable that this polymer is at least 1 type selected from the polyimide precursor which contains the structural unit represented by the said Formula [4], and the polyimide which is the imide compound.
• the polymers contained in the liquid crystal aligning agent of the present invention may all be the polymers of the present invention, and are different from the polymers of the present invention as long as the effects described in the present invention are exhibited. You may contain 2 or more types of structures. Or in addition to the polymer of this invention, you may contain the other polymer, ie, the polymer which does not have a bivalent group represented by Formula [1] or Formula [2].
• polystyrene-phenylmaleimide poly (meta ) Acrylate and the like.
• the ratio of the polymer of the present invention to the total polymer components is preferably 5% by mass or more, and an example thereof is 5% by mass to 95% by mass. Is mentioned.
• the ratio of the polymer of this invention can be suitably selected according to the characteristic of a liquid crystal aligning agent or a liquid crystal aligning film.
• the liquid crystal aligning agent of the present invention is used for preparing a liquid crystal aligning film, and generally takes the form of a coating liquid from the viewpoint of forming a uniform thin film. Also in the liquid crystal aligning agent of this invention, it is preferable that it is a coating liquid containing an above-described polymer component and the organic solvent in which this polymer component is dissolved. At that time, the concentration of the polymer in the liquid crystal aligning agent can be appropriately changed by setting the thickness of the coating film to be formed. From the viewpoint of forming a uniform and defect-free coating film, the content is preferably 1% by mass or more, and from the viewpoint of storage stability of the solution, it is preferably 10% by mass or less. The concentration of the polymer is particularly preferably 2% by mass to 8% by mass.
• the organic solvent contained in the liquid crystal aligning agent of the present invention is not particularly limited as long as it is an organic solvent that dissolves the polymer.
• Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, ⁇ -butyrolactone, 1,3-dimethyl-imidazolide.
• Non-methyl methyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone and the like can be mentioned.
• N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and ⁇ -butyrolactone are preferably used.
• the organic solvent illustrated here may be used independently or may be used in mixture.
• even a solvent that does not dissolve the polymer may be used by mixing with an organic solvent as long as the produced polymer does not precipitate.
• the organic solvent contained in the liquid crystal aligning agent uses a mixed solvent that is used in combination with a solvent that improves the coating properties and the surface smoothness of the coating film when the liquid crystal aligning agent is applied in addition to the above-described solvents.
• a mixed solvent is also preferably used in the liquid crystal aligning agent of the present invention. Specific examples of the organic solvent to be used in combination are given below, but the organic solvent is not limited to these examples.
• 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- Ethane All, 1,2-propanediol, 1,3-propan
• solvents represented by the following formulas [S-1] to [S-3] can be used.
• R 28 and R 29 represent an alkyl group having 1 to 3 carbon atoms.
• Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group.
• R 30 represents an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group and the like.
• organic solvents used in combination 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene It is preferable to use glycol monobutyl ether or dipropylene glycol dimethyl ether.
• the kind and content of such a solvent are suitably selected according to the coating device, coating conditions, coating environment, etc. of the liquid crystal aligning agent.
• these solvents are preferably 20% by mass to 99% by mass with respect to the whole solvent contained in the liquid crystal aligning agent. Of these, 20% by mass to 90% by mass is preferable. More preferred is 20% by mass to 70% by mass.
• the liquid crystal aligning agent of the present invention may additionally contain components other than the polymer component and the organic solvent as long as the effects of the present invention are not impaired.
• additional components include an adhesion aid for increasing the adhesion between the liquid crystal alignment film and the substrate and the adhesion between the liquid crystal alignment film and the sealing material, a crosslinking agent for increasing the strength of the liquid crystal alignment film, and the liquid crystal alignment.
• examples thereof include dielectrics and conductive materials for adjusting the dielectric constant and electrical resistance of the film. Specific examples of these additional components are as disclosed in various known literatures relating to liquid crystal aligning agents. If an example is given, paragraphs [0105] to [0116] of International Publication No. 2015/060357 may be used. Ingredients disclosed in the above.
• the liquid crystal aligning film of this invention is obtained from the liquid crystal aligning agent mentioned above. If an example of the method of obtaining a liquid crystal aligning film from a liquid crystal aligning agent is given, a liquid crystal aligning agent in the form of a coating solution is applied to a substrate, dried and baked on a film obtained by rubbing or photo-aligning. And a method of performing an alignment treatment.
• the substrate to which the liquid crystal aligning agent of the present invention is applied is not particularly limited as long as it is a highly transparent substrate, and a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used together with a glass substrate or a silicon nitride substrate. At that time, it is preferable to use a substrate on which an ITO electrode or the like for driving the liquid crystal is formed from the viewpoint of simplification of the process.
• an opaque material such as a silicon wafer can be used as long as it is only on one side of the substrate, and a material that reflects light such as aluminum can be used for the electrode in this case.
• the application method of the liquid crystal aligning agent is not particularly limited, but industrially, screen printing, offset printing, flexographic printing, ink jet method and the like are common.
• As other coating methods there are a dipping method, a roll coater method, a slit coater method, a spinner method, a spray method, and the like, and these may be used according to the purpose.
• Firing after applying the liquid crystal aligning agent on the substrate is performed at 50 ° C. to 300 ° C., preferably 80 ° C. to 250 ° C. by a heating means such as a hot plate, a hot-air circulating furnace, an infrared furnace, and the solvent is evaporated, A coating film (liquid crystal alignment film) can be formed. If the thickness of the coating film formed after firing is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered. The thickness is preferably 10 nm to 100 nm. When the liquid crystal is aligned horizontally or tilted, the fired coating film is treated by rubbing or irradiation with polarized ultraviolet rays.
• the solvent is evaporated and baked by a heating means such as a hot plate, a thermal circulation oven, an IR (infrared) oven or the like.
• a heating means such as a hot plate, a thermal circulation oven, an IR (infrared) oven or the like.
• Arbitrary temperature and time can be selected for the drying and baking steps after applying the liquid crystal aligning agent.
• the liquid crystal alignment film of the present invention is suitable as a liquid crystal alignment film for a horizontal electric field type liquid crystal display element such as an IPS mode or an FFS mode, and is particularly useful as a liquid crystal alignment film for an FFS mode liquid crystal display element.
• the liquid crystal display element of the present invention comprises the above-mentioned liquid crystal alignment film, and after obtaining a substrate with a liquid crystal alignment film obtained from the above-mentioned liquid crystal aligning agent, a liquid crystal cell is prepared by a known method, An element is formed using a liquid crystal cell.
• a liquid crystal cell As an example, two substrates disposed so as to face each other, a liquid crystal layer provided between the substrates, and a liquid crystal formed between the substrate and the liquid crystal layer and formed by the liquid crystal aligning agent of the present invention.
• a liquid crystal display element comprising a liquid crystal cell having an alignment film.
• the substrate used in the liquid crystal display element of the present invention 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.
• a substrate on which a transparent electrode for driving liquid crystal is formed.
• substrate described with the above-mentioned liquid crystal aligning film can be mentioned.
• liquid crystal alignment film is formed by applying the liquid crystal aligning agent of the present invention on this substrate and baking it, and the details are as described above.
• the liquid crystal material constituting the liquid crystal layer of the liquid crystal display element of the present invention is not particularly limited, and examples thereof include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable, and any of positive liquid crystal materials and negative liquid crystal materials can be used. It may be used. Specifically, for example, MLC-2003, MLC-6608, MLC-6609, MLC-3019, MLC-2041, MLC-7026-100 manufactured by Merck & Co., Inc. can be used.
• a transparent glass substrate is prepared, a common electrode is provided on one substrate, and a segment electrode is provided on the other substrate.
• These electrodes can be ITO electrodes, for example, and are patterned so as to display a desired image.
• an insulating film is provided on each substrate so as to cover the common electrode and the segment electrode.
• the insulating film can be, for example, a film made of SiO 2 —TiO 2 formed by a sol-gel method.
• a liquid crystal alignment film is formed on each substrate under the above conditions.
• an ultraviolet curable sealing material is disposed at a predetermined position on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is disposed at predetermined positions on the liquid crystal alignment film surface.
• the other substrate is bonded and pressure-bonded so that the liquid crystal alignment film faces, and the liquid crystal is spread on the front surface of the liquid crystal alignment film, and then the entire surface of the substrate is irradiated with ultraviolet rays to cure the sealing material. Get a cell.
• an opening that can be filled with liquid crystal from the outside is provided when a sealing material is disposed at a predetermined location on one substrate.
• a liquid crystal material is injected into the liquid crystal cell through an opening provided in the sealing material, and then the opening is sealed with an adhesive to obtain a liquid crystal cell.
• the liquid crystal material may be injected by a vacuum injection method or a method utilizing capillary action in the atmosphere.
• a polarizing plate is installed. Specifically, it is preferable to attach a pair of polarizing plates to the surfaces of the two substrates opposite to the liquid crystal layer.
• the liquid crystal alignment film and the liquid crystal display element of the present invention are not limited to the above description as long as the liquid crystal aligning agent of the present invention is used, and may be prepared by other known methods. Good. Processes for obtaining a liquid crystal display element from a liquid crystal aligning agent are also disclosed in a number of documents in addition to paragraphs [0074] to [0081] of JP-A-2015-135393, for example.
• the liquid crystal display device manufactured using the liquid crystal aligning agent of the present invention has excellent reliability and can be suitably used for a large-screen high-definition liquid crystal television or the like.
• Zinc chloride (120.3 g, 882 mmol) was added to a 3 L (liter) four-necked flask, and the temperature was raised to 100 ° C., followed by vacuum drying for 1 hour with an oil pump. Thereafter, at room temperature under a nitrogen atmosphere, toluene (460 g), diethylamine (45.0 g, 615 mmol), t-butanol (46.4 g, 626 mmol), 2-bromo-4-nitroacetophenone (100.0 g, 410 mmol), 4-Nitroacetophenone (104.2 g, 631 mmol) was sequentially added, and the mixture was stirred at room temperature for 3 days.
• This reaction solution was added to 434.4 g of methanol with stirring, and the deposited precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 60 ° C. to obtain a polyimide powder. The imidation ratio of this polyimide was 75%. 80.0 g of NMP was added to 20.0 g of the obtained polyimide powder, and dissolved by stirring at 70 ° C. for 20 hours to obtain a polyimide solution (SPI-B4).
• a glass substrate with an electrode having a size of 30 mm ⁇ 35 mm and a thickness of 0.7 mm was prepared.
• an IZO electrode having a solid pattern constituting a counter electrode as a first layer is formed on the substrate.
• a SiN (silicon nitride) film formed by the CVD method is formed as the second 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. ing.
• 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 are electrically insulated by the action of the second-layer SiN film.
• the pixel electrode of the third layer is a comb tooth formed by arranging a plurality of electrode elements having a U-shape with a bent central portion as shown in FIG. 3 (Japanese Patent Laid-Open No. 2014-77845). It has a shape. The width in the short direction of each electrode element is 3 ⁇ m, and the distance between the electrode elements is 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 is bent and has a shape similar to the bold “ku” character. Each pixel is divided into upper and lower portions with a 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 described later is used as a reference, the electrode element of the pixel electrode is formed to form an angle of + 10 ° (clockwise) in the first region of the pixel, and the pixel in the second region of the pixel.
• the electrode elements of the electrode are formed so as to form an angle of ⁇ 10 ° (clockwise).
• 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 in the substrate surface are mutually It is comprised so that it may become a reverse direction.
• spin coated After drying for 5 minutes on an 80 degreeC hotplate, it baked for 20 minutes at 230 degreeC, and obtained the 60-nm-thick polyimide film on each board
• the polyimide film surface is rubbed with a rayon cloth under the conditions of a roll diameter of 120 mm, a roller rotation speed of 500 rpm, a stage moving speed of 30 mm / sec, and a rubbing cloth indentation pressure of 0.3 mm, and then in pure water for 1 minute. Ultrasonic irradiation was performed, and drying was performed at 80 ° C. for 10 minutes.
• liquid crystal alignment film Using the two types of substrates with the above-mentioned liquid crystal alignment film, the rubbing directions were combined to be antiparallel, the periphery was sealed leaving the liquid crystal injection port, and an empty cell with a cell gap of 3.8 ⁇ m was produced. .
• Liquid crystals (MLC-3019, manufactured by Merck & Co., Inc.) were vacuum-injected into this empty cell at room temperature, and the injection port was sealed to obtain an anti-parallel alignment liquid crystal cell.
• the obtained liquid crystal cell constitutes an FFS mode liquid crystal display element. Thereafter, the liquid crystal cell was heated at 120 ° C. for 1 hour and allowed to stand overnight before being used for evaluation.
• the afterimage was evaluated using the following optical system and the like. That is, the prepared liquid crystal cell is placed between two polarizing plates arranged so that the polarization axes are orthogonal to each other, and the LED backlight is turned on with no voltage applied, so that the brightness of transmitted light is minimized. Further, the arrangement angle of the liquid crystal cell was adjusted. Next, a VT curve (voltage-transmittance curve) was measured while applying an AC voltage with a frequency of 30 Hz to the liquid crystal cell, and an AC voltage with a relative transmittance of 23% was calculated as a drive voltage.
• VT curve voltage-transmittance curve
• a DC voltage of 1 V was applied at the same time while driving the liquid crystal cell by applying an AC voltage of 30 Hz with a relative transmittance of 23%, and the liquid crystal cell was driven for 30 minutes. Thereafter, the applied DC voltage value was set to 0 V, and only the application of the DC voltage was stopped, and the device was further driven for 15 minutes in this state.
• the time during which the relative transmittance decreased to 30% or less by the time 30 minutes elapsed from the start of application of the DC voltage was quantified. Evaluation was made by defining “ ⁇ ” when the relative transmittance decreased to 30% or less within 5 minutes, and “ ⁇ ” when within 6 to 30 minutes. When it took 30 minutes or more before the relative transmittance decreased to 30% or less, the afterimage was not erased, and “x” was defined and evaluated. And the afterimage evaluation according to the method mentioned above was performed on the temperature conditions of the state whose temperature of a liquid crystal cell is 23 degreeC.
• the rotation angle when the liquid crystal cell was rotated from the angle at which the second region of the first pixel became darkest to the angle at which the first region became darkest was calculated as an angle ⁇ .
• the second area was compared with the first area, and a similar 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. The smaller the value of the angle ⁇ of the liquid crystal cell, the better the stability of the liquid crystal alignment.
• the liquid crystal display elements using the liquid crystal aligning agents of Examples 1 to 4 have a quick relaxation of accumulated charges, and improved orientation and transparency.
• the liquid crystal display elements using the liquid crystal aligning agents of Examples 1 to 4 and 19 have a quick relaxation of accumulated charges and improved alignment and transparency. You can see that

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