JP7159755B2 - Liquid crystal alignment agent, liquid crystal alignment film, optical film and liquid crystal element - Google Patents

Description

TECHNICAL FIELD The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, an optical film and a liquid crystal element .

In a liquid crystal display device, an optical film, or the like, the transmission of light is controlled by controlling the orientation of liquid crystal molecules. These liquid crystal display devices and optical films are provided with a liquid crystal alignment film having a function of orienting liquid crystal molecules in a liquid crystal layer in a certain direction. A liquid crystal alignment film is generally formed on a substrate by applying a liquid crystal alignment agent obtained by dissolving a polymer component in an organic solvent on the surface of the substrate, and preferably by heating.

Various liquid crystal aligning agents using water or a water-soluble solvent as a solvent component instead of or together with an organic solvent have been proposed (see, for example, Patent Documents 1 and 2). Patent Document 1 discloses that an amine compound such as 1-diethylamino-3-butanone and a polyamic acid are combined to form a coating of a polycarboxylic acid salt aqueous solution, followed by rubbing to prepare a liquid crystal alignment film. Further, Patent Document 2 discloses that a liquid crystal alignment film is produced by a photo-alignment method using a liquid crystal alignment agent obtained by dissolving an onium salt such as a triethylamine salt of an acrylic copolymer in water. By using such a water-based liquid crystal aligning agent, low-temperature baking becomes possible during film formation. This has the advantage of easing restrictions on the substrate material and being friendly to the work environment.

JP-A-8-87017 JP 2016-224151 A

It cannot be said that the liquid crystal alignment films obtained using the water-based liquid crystal aligning agents of Patent Documents 1 and 2 have sufficient transparency required for applications such as liquid crystal display devices and optical films.

In addition, the liquid crystal alignment film is required to have solvent resistance in order to prevent alteration and quality deterioration during the manufacturing process. Therefore, as a liquid crystal alignment film, it is necessary to improve solvent resistance while ensuring liquid crystal alignment and transparency.

The present invention has been made in view of the above problems, and a main object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal aligning film excellent in liquid crystal alignment, transparency and solvent resistance.

（式（１）中、Ｒ^１は水素原子又は１価の有機基であり、Ｘ^１は４価の有機基であり、Ｘ^２は２価の有機基である。Ｍ^ｎ＋は、典型金属元素又は遷移金属元素を有するｎ価の陽イオンである。ｎは１以上の整数である。ｍ１は１又は２であり、ｍ２は０又は１であり、ｍ１＋ｍ２＝２を満たす。）
［２］ ポリアミック酸、ポリアミック酸エステル及びポリイミドよりなる群から選ばれる少なくとも一種の重合体と、典型金属元素又は遷移金属元素を有する塩基と、水と、を含有する、液晶配向剤。
［３］ 上記［１］又は［２］の液晶配向剤を用いて形成された液晶配向膜。
［４］ 上記［３］の液晶配向膜を具備する光学フィルム。
［５］ 上記［３］の液晶配向膜を具備する液晶素子。
［６］ ポリアミック酸、ポリアミック酸エステル及びポリイミドよりなる群から選ばれる少なくとも一種の重合体と、典型金属元素又は遷移金属元素を有する塩基と、水と、を混合する、液晶配向剤の製造方法。
［７］ 上記［１］又は［２］の液晶配向剤を一対の基板のそれぞれに塗布し、前記一対の基板上に塗膜を形成する工程と、前記一対の基板における前記塗膜の形成面に不動態化処理を行う工程と、を含む、液晶配向膜の製造方法。
［８］ 上記［１］又は［２］の液晶配向剤を一対の基板のそれぞれに塗布し、光を照射することにより液晶配向膜を形成する工程と、前記液晶配向膜を形成した一対の基板を、液晶層を挟んで前記液晶配向膜が対向するように配置して液晶セルを構築する工程と、を含む、光学フィルムの製造方法。
［９］ 上記式（１）で表される部分構造を有する重合体。 In order to solve the problems of the prior art as described above, we have made intensive studies and found that the above problems can be solved by including a polycarboxylate salt of an inorganic ion (M ⁿ⁺ ) as a polymer component of the liquid crystal aligning agent. , have completed the present invention. Specifically, the present invention provides the following means.
[1] A liquid crystal aligning agent containing a polymer having a partial structure represented by the following formula (1).

(In formula (1), R ¹ is a hydrogen atom or a monovalent organic group, X ¹ is a tetravalent organic group, and X ² is a divalent organic group. M ⁿ⁺ is a typical metal element or an n-valent cation having a transition metal element, n is an integer of 1 or more, m1 is 1 or 2, m2 is 0 or 1, and satisfies m1+m2=2.)
[2] A liquid crystal aligning agent containing at least one polymer selected from the group consisting of polyamic acids, polyamic acid esters and polyimides, a base having a typical metal element or a transition metal element, and water.
[3] A liquid crystal alignment film formed using the liquid crystal alignment agent of [1] or [2] above.
[4] An optical film comprising the liquid crystal alignment film of [3] above.
[5] A liquid crystal device comprising the liquid crystal alignment film of [3] above.
[6] A method for producing a liquid crystal aligning agent, comprising mixing at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, a base having a typical metal element or a transition metal element, and water.
[7] A step of applying the liquid crystal alignment agent of [1] or [2] above to each of a pair of substrates to form a coating film on the pair of substrates, and a surface on which the coating film is formed on the pair of substrates. A method for producing a liquid crystal alignment film, comprising a step of performing a passivation treatment.
[8] A step of applying the liquid crystal aligning agent of [1] or [2] above to each of a pair of substrates and irradiating light to form a liquid crystal alignment film, and a pair of substrates on which the liquid crystal alignment film is formed. and constructing a liquid crystal cell by arranging so that the liquid crystal alignment films face each other with the liquid crystal layer interposed therebetween.
[9] A polymer having a partial structure represented by the above formula (1).

According to the liquid crystal aligning agent of the present invention, by containing a salt of at least one polymer selected from the group consisting of polyamic acids, polyamic acid esters and polyimides and inorganic ions (M ⁿ⁺ ), liquid crystal alignment properties and transparency are improved. A liquid crystal alignment film having excellent properties and solvent resistance can be obtained.

≪Liquid crystal aligning agent≫
The liquid crystal aligning agent of the present disclosure contains a polymer component. Below, the component contained in a liquid crystal aligning agent and the other component mix|blended arbitrarily as needed are demonstrated.

As used herein, the term "hydrocarbon group" includes a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. A "chain hydrocarbon group" means a straight chain hydrocarbon group or a branched hydrocarbon group that does not contain a cyclic structure in its main chain and is composed only of a chain structure. However, it may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, it does not have to be composed only of an alicyclic hydrocarbon structure, and includes those having a chain structure in part thereof. An "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it does not have to be composed only of an aromatic ring structure, and may partially contain a chain structure or an alicyclic hydrocarbon structure.

（式（１）中、Ｒ^１は水素原子又は１価の有機基であり、Ｘ^１は４価の有機基であり、Ｘ^２は２価の有機基である。Ｍ^ｎ＋は、典型金属元素又は遷移金属元素を有するｎ価の陽イオンである。ｎは１以上の整数である。ｍ１は１又は２であり、ｍ２は０又は１であり、ｍ１＋ｍ２＝２を満たす。） <Polymer component>
The liquid crystal aligning agent contains a polymer (hereinafter also referred to as "polymer (P)") having a partial structure represented by the following formula (1).

(In formula (1), R ¹ is a hydrogen atom or a monovalent organic group, X ¹ is a tetravalent organic group, and X ² is a divalent organic group. M ⁿ⁺ is a typical metal element or an n-valent cation having a transition metal element, n is an integer of 1 or more, m1 is 1 or 2, m2 is 0 or 1, and satisfies m1+m2=2.)

In the above formula (1), the monovalent organic group represented by R ¹ includes, for example, a monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent group having a cinnamate structure, and the like. R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
X1 is ^a tetravalent group derived from a tetracarboxylic acid derivative and is a residue obtained by removing an acid anhydride group, a carboxyl group, an ester group and an acyl halide group from the tetracarboxylic acid derivative. In this specification, the term "tetracarboxylic acid derivative" includes tetracarboxylic dianhydrides, tetracarboxylic diesters and tetracarboxylic diester dihalides.
X2 is a ^divalent group derived from a diamine compound and is a residue obtained by removing two primary amino groups from the diamine compound.

For ^Mn+ , specific examples of cations having typical metal elements include Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Be ²⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Al ³⁺ and the like. . Specific examples of cations having a transition metal element include Sc ³⁺ , Ti ⁴⁺ , V ²⁺ , V ³⁺ , V ⁴⁺ , V ⁵⁺ , Cr ³⁺ , Cr ⁴⁺ , Cr ⁶⁺ , Mn ²⁺ , Mn ³⁺ , Mn ⁴⁺ , Fe ²⁺ , Fe ³⁺ , Co ²⁺ , Co ³⁺ , Ni ²⁺ , Cu ⁺ , Cu ²⁺ , Zu ²⁺ , Pb ²⁺ and the like. Among these, ^Mn+ is preferably a cation having a typical metal element, more preferably a cation having an alkali metal, and particularly preferably Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ or Cs ⁺ .
n is preferably 1 to 4, preferably 1 or 2, and particularly preferably 1.

The liquid crystal aligning agent containing the polymer (P) is composed of at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide (hereinafter also referred to as "polymer (A)") and a typical metal. It can be obtained by mixing a base containing an element or a transition metal element (hereinafter also referred to as “base (B)”) and water. The polymer (A) can also be said to be a precursor of the polymer (P).

(polyamic acid)
A polyamic acid can be obtained by reacting a tetracarboxylic dianhydride and a diamine compound.
Tetracarboxylic dianhydride Tetracarboxylic dianhydrides used in the synthesis of polyamic acids include, for example, aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aromatic tetracarboxylic dianhydrides. things can be mentioned. Specific examples thereof include aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride;
Alicyclic tetracarboxylic dianhydrides such as 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1 ,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, etc. ; aromatic tetracarboxylic dianhydrides such as pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, ethylene glycol bisanhydrotrimate, 4,4'-(hexa fluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-oxydiphthalic anhydride, propane-1,3-diylbis(1,3-dioxo-1,3-dihydro isobenzofuran-5-carboxylate), etc., and tetracarboxylic dianhydrides described in JP-A-2010-97188 can be used. In addition, as a tetracarboxylic dianhydride, it can be used individually by 1 type or in combination of 2 or more types.

（式（Ｅ－１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、－Ｏ－、＊－ＣＯＯ－又は＊－ＯＣＯ－（ただし、「＊」はＸ^Ｉとの結合手を示す。）であり、Ｒ^Ｉは炭素数１～３のアルカンジイル基であり、Ｒ^ＩＩは単結合又は炭素数１～３のアルカンジイル基であり、ａは０又は１であり、ｂは０～２の整数であり、ｃは１～２０の整数であり、ｄは０又は１である。但し、ａ及びｂが同時に０になることはない。）
で表される化合物、光配向性基を側鎖に有するジアミン等の側鎖型ジアミン： - Diamine compound Examples of diamine compounds used for synthesizing polyamic acids include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes. Specific examples of these diamines include metaxylylenediamine, 1,3-propanediamine, hexamethylenediamine, etc. as aliphatic diamines; 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine) and the like;
As aromatic diamines, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5 -diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, 3,5-diaminobenzo lanostanyl acid, 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 2,4-diamino-N,N-diallylaniline, 4-(4'-tri fluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 3,5-diaminobenzoic acid = 5ξ-cholestane- 3-yl, the following formula (E-1)

(In formula (E-1), X ^I and X ^II are each independently a single bond, -O-, *-COO- or *-OCO- (where "*" is a bond with X ^I ), R ^I is an alkanediyl group having 1 to 3 carbon atoms, R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is 0 is an integer of ~2, c is an integer of 1 to 20, and d is 0 or 1. However, a and b are not 0 at the same time.)
A compound represented by, a side chain type diamine such as a diamine having a photoalignment group in the side chain:

p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4-aminophenyl-4-aminobenzoate, 4,4'-diaminoazobenzene, 3,5-diaminobenzoic acid, 1,5-bis(4-aminophenoxy) Pentane, 1,2-bis(4-aminophenoxy)ethane, bis[2-(4-aminophenyl)ethyl]hexanedioic acid, N,N-bis(4-aminophenyl)methylamine, 1,4-bis -(4-aminophenyl)-piperazine, N,N'-bis(4-aminophenyl)-benzidine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl )-4,4′-diaminobiphenyl, 4,4′-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis(4-aminophenyl)hexafluoropropane , 4,4′-(phenylenediisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 4,4′-bis(4-aminophenoxy)biphenyl, 4,4′-[4,4 '-propane-1,3-diylbis(piperidine-1,4-diyl)]dianiline, 4,4'-diaminobenzanilide, 4,4'-diaminostilbenzene, 4,4'-diaminodiphenylamine, 1,3 -bis(4-aminophenethyl)urea, 1,3-bis(4-aminobenzyl)urea, 1,4-bis(4-aminophenyl)-piperazine, N-(4-aminophenylethyl)-N-methyl amines, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, main chain type diamines such as diamines having a photo-orientation group in the main chain; 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and the like can be mentioned, respectively, and diamines described in JP-A-2010-97188 can also be used.

- Synthesis of polyamic acid A polyamic acid can be obtained by reacting a tetracarboxylic dianhydride and a diamine compound together with, if necessary, a molecular weight modifier (for example, an acid unihydride, a monoamine, etc.). The ratio of the tetracarboxylic dianhydride and the diamine compound used in the synthetic reaction of the polyamic acid is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 to 0.2 to 1 equivalent of the amino group of the diamine compound. A ratio of 2 equivalents is preferred.

The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. At this time, the reaction temperature is preferably −20° C. to 150° C., and the reaction time is preferably 0.1 to 24 hours. Examples of organic solvents used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol and xylenol. and halogenated phenols, or a mixture of one or more of these and other organic solvents (e.g., butyl cellosolve, diethylene glycol diethyl ether, etc.) can be used. preferable. The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine is 0.1 to 50% by mass with respect to the total amount (a+b) of the reaction solution. is preferred.

(polyamic acid ester)
Polyamic acid esters can be obtained by, for example, [I] a method of reacting the polyamic acid obtained by the above synthetic reaction with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine compound, [III] tetracarboxylic acid It can be obtained by a method of reacting an acid diester dihalide with a diamine compound, or the like. The polyamic acid ester contained in the liquid crystal aligning agent may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist.

(polyimide)
Polyimide can be obtained, for example, by dehydrating and ring-closing the polyamic acid synthesized as described above to imidize it. The imidization rate of the polyimide is preferably 80% or less, more preferably 50% or less, from the viewpoint of better solubility in water or water-soluble organic solvents. Although the lower limit of the imidization rate is not particularly limited, it is preferably 20% or more, more preferably 30% or more. The imidization rate is expressed as a percentage of the ratio of the number of imide ring structures to the sum of the number of amic acid structures and the number of imide ring structures of polyimide. A part of the imide ring may be an isoimide ring.

The dehydration and ring closure of the polyamic acid is preferably carried out by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration and ring closure catalyst to the solution, and heating if necessary. In this method, the dehydrating agent includes, for example, acid anhydrides such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride. The dehydrating agent is preferably used in an amount of 0.01 to 20 mol per 1 mol of the amic acid structure of the polyamic acid. Tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used as the dehydration ring-closing catalyst. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol per 1 mol of the dehydrating agent used. Examples of the organic solvent used in the dehydration ring-closure reaction include the organic solvents exemplified as those used in the synthesis of the polyamic acid. The reaction temperature for the dehydration ring closure reaction is preferably 0 to 180°C. The reaction time is preferably 1.0 to 120 hours.

(Photo-orientation group)
The polymer (P) can be a polymer having photoalignable groups. In this case, the organic film formed using the liquid crystal aligning agent is preferably provided with a liquid crystal aligning ability by a photo-alignment method. Here, the photo-orientation group refers to a functional group capable of imparting anisotropy to a film by a photo-reaction such as photo-isomerization reaction, photo-dimerization reaction, photo-fries rearrangement reaction or photo-decomposition reaction due to photo-irradiation.

Specific examples of photo-orientation groups include, for example, azobenzene-containing groups containing azobenzene or derivatives thereof as a basic skeleton, cinnamic acid structure-containing groups containing cinnamic acid or derivatives thereof (cinnamic acid structure) as a basic skeleton, chalcones or derivatives thereof. a chalcone-containing group containing as a basic skeleton, a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, stilbene or Examples include a stilbene-containing group having a derivative thereof as a basic skeleton, a phenylbenzoate-containing group containing phenylbenzoate or a derivative thereof as a basic skeleton, and the like. Among these, the photoalignment group is preferably at least one selected from the group consisting of an azobenzene-containing group, a cinnamic acid structure-containing group, a chalcone-containing group, a stilbene-containing group, a cyclobutane-containing structure, and a phenylbenzoate-containing group. , a cinnamic acid structure-containing group or a cyclobutane-containing structure is preferred in terms of high sensitivity to light and ease of introduction into the polymer.

A polymer having a photo-alignment group can be obtained, for example, by polymerization using a monomer having a photo-alignment group. The content of the photo-alignment group in the polymer (A) (that is, the content of the photo-alignment group in the polymer (P)) is such that the desired liquid crystal alignment ability is imparted to the coating film. For example, in the case of a cinnamic acid structure-containing group, it is preferably 5 mol% or more with respect to the total structural units of the polymer having a photoalignment group, and 10 to 80 mol. % is more preferable. When the photo-alignment group is a cyclobutane-containing structure, the content of the photo-alignment group is preferably 10 mol% or more with respect to the total structural units of the polymer having the photo-alignment group, and is preferably 15 to 80 mol. % is more preferable.

The solution viscosity of the polymer used for preparing the liquid crystal aligning agent is preferably one having a solution viscosity of 10 to 800 mPa s when the solution has a concentration of 10% by mass, and a solution viscosity of 15 to 500 mPa s. It is more preferable to have In addition, the solution viscosity (mPa s) is obtained by measuring a polymer solution with a concentration of 10% by mass prepared using a good polymer solvent (γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) with an E-type rotational viscometer. is a value measured at 25°C using

The polystyrene equivalent weight average molecular weight (Mw) of the polymer (A) measured by gel permeation chromatography (GPC) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. is. In addition, the molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene equivalent number average molecular weight (Mn) measured by GPC is preferably 7 or less, more preferably 5 or less.

(Base (B))
The base (B) is a salt composed of a cation (M ⁿ⁺ ) having a typical metal element or transition metal element and a counterion.

Examples of counter ions possessed by the base (B) include halide ions, inorganic acid ions and organic acid ions. Specific examples of these include halide ions such as fluoride ion (F ⁻ ), chloride ion (Cl ⁻ ), bromide ion (Br ⁻ ), iodide ion (I ⁻ ), and the like;
Examples of inorganic acid ions include hydroxide ions, hydrogen carbonate ions, carbonate ions, sulfate ions, hydrogen sulfate ions, phosphate ions, hydrogen phosphate ions, dihydrogen phosphate ions, phosphinate ions, nitrate ions, and borate ions. , sulfite ions, hypochlorite ions, perchlorate ions, thiocyanate ions, hydrofluoric acid ions, etc.;
Examples of organic acid ions include acetate ion, trimethylacetate ion, trifluoroacetate ion, trifluoromethanesulfonate ion, tetraphenylborate ion, alkoxide ion having 1 to 10 carbon atoms (methoxide ion, ethoxide ion, propoxide ion, , n-butoxide ion, tert-butoxide ion, 2-methyl-2-butoxide ion, etc.), propionate ion, butyrate ion, formate ion, lactate ion, citrate ion, succinate ion, oxalate ion, tartrate ion, fumarate ion, maleate ion, malonate ion, aniline ion, benzoate ion, glycine ion, pyridine ion, phenol ion, aniline sulfonate ion, thiocarboxylate ion, methylsulfinate ion, methyl sulfate ion, ethyl sulfate ion, Amidosulfate ions, valerate ions, dodecylbenzenesulfonate ions, and the like can be mentioned, respectively.

The base (B) is preferably a weak base in that a liquid crystal alignment film having higher liquid crystal alignment properties can be obtained. As used herein, the weak base refers to a salt of a weak acid having a pKa of 4 or more in water at 25°C. Weak acids with a pKa of 4 or more include carboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, and benzoic acid; methanol, ethanol, propanol, n-butanol, tert-butanol, 2-methyl-2-butanol. alcohols having 1 to 10 carbon atoms such as; inorganic acids such as boric acid, carbonic acid and formic acid; When the counterion is a weak acid ion, it is particularly preferably an ion derived from one selected from the group consisting of inorganic acids and alcohols having 1 to 10 carbon atoms.
As the base (B), it is preferable to use a salt of an alkali metal and a weak acid because the liquid crystal orientation, transparency and solvent resistance of the resulting alignment film can be well balanced.

The blending ratio of the base (B) is preferably 10 to 150 mol parts, more preferably 20 to 120 mol parts, with respect to 100 mol parts of all monomer units possessed by the polymer (A). It is more preferable to use up to 100 mole parts. In addition, a base (B) can be used individually by 1 type or in combination of 2 or more types.

(solvent)
The liquid crystal aligning agent of the present disclosure is a water-based polymer composition containing water as a solvent component. In this case, the amount of the organic solvent used can be reduced, and the liquid crystal aligning agent can be more excellent in terms of environment and safety, which is preferable.

As the solvent component, water may be used alone, but from the viewpoint of improving the solubility of the polymer in the solvent and improving the coatability on the substrate, it is water-soluble and has a higher surface tension than water. A mixed solvent of a low solvent (hereinafter also referred to as "solvent Q") and water is preferred, and a mixed solvent of water and alcohol is particularly preferred.

The solvent Q is preferably a compound in which the hydrogen atom of a chain hydrocarbon whose methylene group may be substituted with -O- or -COO- is substituted with a hydroxyl group, such as methanol, ethanol, n-propyl alcohol, isopropyl Alcohol, 1-methoxy-2-propanol (propylene glycol monomethyl ether), diacetone alcohol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, butyl cellosolve (ethylene glycol monobutyl ether), propylene glycol monoethyl ether, 1-hexanol, 4- alcohols such as methyl-2-pentanol; and esters such as ethyl lactate and butyl lactate. When solvent Q is used in combination, the proportion of water used is preferably 20% by mass or more, more preferably 40 to 95% by mass, relative to the total amount of the solvent contained in the liquid crystal aligning agent. It is more preferable to make it to 90% by mass.

As the solvent, a solvent other than water and solvent Q (hereinafter also referred to as "other organic solvent") may be used in combination. Other organic solvents include, for example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 1,3 - aprotic polar solvents such as dimethyl-2-imidazolidinone, 3-butoxy-N,N-dimethylpropanamide, 3-methoxy-N,N-dimethylpropanamide;
Ketone solvents such as 4-hydroxy-4-methyl-2-pentanone, diisobutyl ketone, ethylene carbonate and propylene carbonate;
Ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, diisopentyl ether, tetrahydrofuran; butyl acetate, methyl methoxypropionate, ethyl ethoxy propionate, isoamyl propionate, isoamyl isobutyrate , ester solvents such as propylene glycol diacetate; hydrocarbon solvents such as cyclopentanone and cyclohexanone, and the like. As other organic solvents, one of these can be used alone or two or more of them can be used in combination.
The ratio of other solvents used is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 5% by mass or less relative to the total amount of the solvent contained in the liquid crystal aligning agent.

(other ingredients)
The liquid crystal aligning agent of the present disclosure contains at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, a base having a typical metal element or transition metal element, and water. Components other than the components (hereinafter also referred to as "other components") may be contained.

Other components include, in addition to the solvents described above, epoxy group-containing compounds (e.g., N,N,N',N'-tetraglycidyl-m-xylenediamine, N,N,N',N' -tetraglycidyl-4,4'-diaminodiphenylmethane, etc.), functional silane compounds (e.g., 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, etc.), antioxidants agents, metal chelate compounds, curing catalysts, curing accelerators, surfactants, fillers, dispersants, photosensitizers and the like. The mixing ratio of other components can be appropriately selected according to each compound within a range that does not impair the effects of the present invention.

In order to obtain the polymer (P), the polymer (A) is isolated from the reaction solution, purified if necessary, and then mixed with the base (B) in a solvent containing water. is preferred. In preparing the liquid crystal aligning agent, the polymer (A) and the base (B) are premixed in a solvent containing water, and the obtained polymer solution is further diluted with a solvent to a desired concentration. It may be carried out by adjusting and adding other ingredients blended as necessary. Alternatively, a liquid crystal aligning agent having a desired concentration may be obtained by mixing the polymer (A), the base (B), and optionally other components in a solvent containing water.

The solid content concentration in the liquid crystal aligning agent (ratio of the total mass of components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., but preferably It is in the range of 1 to 10% by mass. If the solid content concentration is less than 1% by mass, the film thickness of the coating film becomes too small, making it difficult to obtain a good liquid crystal alignment film. On the other hand, if the solid content concentration exceeds 10% by mass, the film thickness of the coating film becomes excessively large, making it difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases, resulting in poor applicability. There is a tendency.

<<Liquid crystal alignment film, liquid crystal element and optical film>>
The liquid crystal element and optical film of the present disclosure comprise a liquid crystal alignment film formed using the liquid crystal alignment agent described above.

(liquid crystal element)
The liquid crystal element of the present disclosure has a highly transparent liquid crystal alignment film, and therefore can be effectively applied to various uses. Specifically, various display devices such as clocks, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, information displays, and light control It can be used as a device (light control film) or the like.
When used as a liquid crystal display device, the operation mode of the liquid crystal is not particularly limited. Specific examples include TN type, STN type, vertical alignment type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB (Optically Compensated Bend) type, and the like.

A method for manufacturing the liquid crystal display element will be described below. The liquid crystal display element can be manufactured, for example, by a method including steps 1 to 3 below. Step 1 uses different substrates depending on the desired mode of operation. Steps 2 and 3 are common to each operation mode.

(Step 1: Formation of coating film)
First, a liquid crystal aligning agent is applied onto a substrate, and preferably the coated surface is heated to form a coating film on the substrate. Examples of the substrate include glass such as float glass and soda glass; and transparent substrates made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly(alicyclic olefin). The transparent conductive film provided on one surface of the substrate includes an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ) and an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ). etc. can be used. When manufacturing a TN-type, STN-type or VA-type liquid crystal element, two substrates provided with patterned transparent conductive films are used. On the other hand, in the case of manufacturing an IPS-type or FFS-type liquid crystal element, a substrate provided with electrodes made of a transparent conductive film or a metal film patterned in a comb shape and a counter substrate provided with no electrodes are used. Use As the metal film, for example, a film made of metal such as chromium can be used. Application of the liquid crystal aligning agent to the substrate is preferably performed on the electrode forming surface by offset printing, spin coating, roll coating, flexographic printing or inkjet printing.

After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably carried out for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-baking temperature is preferably 30-200° C., and the pre-baking time is preferably 0.25-10 minutes. After that, the solvent is completely removed, and if necessary, a baking (post-baking) step is performed for the purpose of thermally imidizing the amic acid structure of the polymer. The baking temperature (post-baking temperature) is preferably 80 to 300° C., and the post-baking time is preferably 5 to 200 minutes. The thickness of the film thus formed is preferably 0.001 to 1 μm. After apply|coating a liquid crystal aligning agent on a board|substrate, the coating film used as a liquid crystal aligning film or a liquid crystal aligning film is formed by removing an organic solvent.

(Step 2: Orientation treatment)
When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal display element, the coating film formed in the above step 1 is subjected to a treatment (orientation treatment) for imparting liquid crystal orientation ability. As a result, the coating film is provided with the ability to align liquid crystal molecules to form a liquid crystal alignment film. Alignment treatment includes rubbing treatment in which the coating film is rubbed in a certain direction with a roll wrapped with cloth made of fibers such as nylon, rayon, cotton, etc., and light irradiation of the coating film formed on the substrate using a liquid crystal alignment agent. and a photo-alignment treatment for imparting liquid crystal alignment ability to the coating film. On the other hand, when manufacturing a vertically aligned liquid crystal element, the coating film formed in the above step 1 can be used as a liquid crystal alignment film as it is. etc.) may be applied. A liquid crystal aligning agent suitable for a vertical alignment type liquid crystal display element can also be suitably used for a PSA (Polymer Sustained Alignment) type liquid crystal display element.

When the liquid crystal aligning agent contains a polymer having a photo-aligning group, it is preferable to form the liquid crystal alignment film by a photo-alignment method. In this case, it is possible to impart uniform liquid crystal orientation to the photosensitive organic film while suppressing the generation of static electricity and dust, and it is possible to precisely control the direction of liquid crystal orientation. Light irradiation for photo-alignment is a method of irradiating the coating film after the post-baking process, a method of irradiating the coating film after the pre-baking process and before the post-baking process, pre-baking process and post-baking process. In at least one of the methods, the coating film is irradiated while the coating film is being heated, or the like. As the radiation to irradiate the coating film, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used. Ultraviolet rays including light with a wavelength of 200 to 400 nm are preferred. When the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized or partially polarized, irradiation may be performed in a direction perpendicular to the substrate surface, obliquely, or a combination thereof. In the case of non-polarized radiation, the irradiation direction is oblique.

Examples of light sources to be used include low pressure mercury lamps, high pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps and excimer lasers. The dose of radiation is preferably 400 to 50,000 J/m ² , more preferably 1,000 to 20,000 J/m ² . After light irradiation for imparting alignment ability, the substrate surface is washed with, for example, water, an organic solvent (eg, methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.), or a mixture thereof. A treatment to heat the substrate may be performed.

It is preferable to passivate the surface of the liquid crystal alignment film formed on the substrate. This treatment is preferable in that the solvent resistance of the liquid crystal alignment film can be further enhanced. The passivation treatment is performed by contacting the film surface with a metal compound (base) having a higher valence than ^Mn+ of the polymer (P). As a result, the ^Mn+ of the polymer (P) is converted to a metal ion with a higher valence to form a passive film on the film surface. As the base used for the passivation treatment, when ^Mn+ is a monovalent cation, for example, a salt of a divalent or higher cation such as calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, etc. It can be preferably used.

(Step 3: Construction of liquid crystal cell)
Subsequently, two substrates on which liquid crystal alignment films are formed as described above are prepared, and a liquid crystal cell is manufactured by arranging liquid crystal between the two substrates facing each other. In order to manufacture a liquid crystal cell, for example, (1) two substrates are arranged facing each other with a gap (spacer) interposed so that the liquid crystal alignment films face each other, and the periphery of the two substrates is sealed using a sealant. A method of sealing the injection hole after injecting liquid crystal into the cell gap partitioned by the substrate surface and the sealing agent, (2) Sealing at a predetermined place on one of the substrates on which the liquid crystal alignment film is formed. After applying the agent and dropping the liquid crystal on several predetermined places on the surface of the liquid crystal alignment film, the other substrate is attached so that the liquid crystal alignment film faces each other and the liquid crystal is spread over the entire surface of the substrate (ODF method ) and the like. It is desirable to remove the flow orientation at the time of liquid crystal filling by heating the manufactured liquid crystal cell to a temperature at which the liquid crystal used assumes an isotropic phase and then slowly cooling to room temperature.

As the sealant, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as spacers can be used. A photospacer, a bead spacer, or the like can be used as the spacer. Liquid crystals include nematic liquid crystals and smectic liquid crystals, among which nematic liquid crystals are preferred. Further, nematic liquid crystals or smectic liquid crystals may be used by adding, for example, cholesteric liquid crystals, chiral agents, ferroelectric liquid crystals, and the like.

Subsequently, a polarizing plate is attached to the outer surface of the liquid crystal cell as required. Examples of the polarizing plate include a polarizing plate in which a polarizing film called "H film" in which iodine is absorbed while stretching orientation of polyvinyl alcohol is sandwiched between cellulose acetate protective films, or a polarizing plate composed of the H film itself. Thus, a liquid crystal display device is obtained.

(optical film)
In order to produce, for example, a retardation film as an optical film, first, the liquid crystal aligning agent prepared above is applied onto a substrate, and the applied surface is preferably heated (baked) to form a coating film. As the substrate, a transparent substrate made of a synthetic resin such as triacetyl cellulose (TAC), polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polyamide, polyimide, polymethyl methacrylate, polycarbonate, or the like is preferable. Application onto the substrate can be performed by, for example, a bar coater method, a spinner method, a printing method, an inkjet method, a roll coater method, or the like. The baking temperature is preferably 40-150°C, more preferably 80-140°C. The heating time is preferably 0.1 to 15 minutes, more preferably 1 to 10 minutes.

Next, by irradiating the coating film formed on the substrate with light, the coating film is imparted with liquid crystal alignment ability. Examples of light to be irradiated include ultraviolet light including light with a wavelength of 150 to 800 nm, visible light, and the like. Among these, ultraviolet light containing light with a wavelength of 300 to 400 nm is preferred. The illuminating light may be polarized or unpolarized. As polarized light, it is preferable to use light including linearly polarized light.

When the light used is polarized light, the light irradiation may be performed in a direction perpendicular to or oblique to the substrate surface, or in combination thereof. When irradiating with non-polarized light, it is necessary to irradiate from an oblique direction with respect to the substrate surface. The irradiation amount of light is preferably 0.1 mJ/cm ² or more and less than 1,000 mJ/cm ² , more preferably 1 to 500 mJ/cm ² . It is preferable to perform a passivation treatment on the coating film (liquid crystal alignment film) after light irradiation in order to improve the solvent resistance. For the explanation of the passivation treatment, the above explanation of the manufacturing method of the liquid crystal display element is applied.

Then, a polymerizable liquid crystal is applied onto the coating film after light irradiation as described above and cured. Thereby, a coating film (liquid crystal layer) containing a polymerizable liquid crystal is formed. The polymerizable liquid crystal used here is a liquid crystal compound or liquid crystal composition that is polymerized by at least one of heating and light irradiation. The polymerizable liquid crystal may be a mixture of liquid crystal compounds. The polymerizable liquid crystal may be a composition containing a known polymerization initiator, a suitable solvent, and the like.
Appropriate coating methods such as a bar coater method, a roll coater method, a spinner method, a printing method, and an inkjet method can be employed to apply the polymerizable liquid crystal as described above onto the formed liquid crystal alignment film. .

Next, the polymerizable liquid crystal coating film formed as described above is subjected to one or more treatments selected from heating and light irradiation to cure the coating film and form a liquid crystal layer. The heating temperature for the coating film is appropriately selected depending on the type of polymerizable liquid crystal to be used. For example, when using Merck's RMS03-013C, it is preferable to heat at a temperature in the range of 40 to 80°C. The heating time is preferably 0.5 to 5 minutes. As the irradiation light, unpolarized ultraviolet rays having a wavelength in the range of 200 to 500 nm can be preferably used. The irradiation amount of light is preferably 50 to 10,000 mJ/cm ² , more preferably 100 to 5,000 mJ/cm ² .
The thickness of the liquid crystal layer to be formed is appropriately set depending on the desired optical properties. For example, when manufacturing a half-wave plate for visible light with a wavelength of 540 nm, the thickness is selected so that the phase difference of the formed retardation film is 240 to 300 nm. The thickness is chosen such that the phase difference is between 120 and 150 nm.

The retardation film thus obtained can be preferably applied as a retardation film for a liquid crystal display device. The driving method of the applied liquid crystal display device is not limited, and various known methods such as TN type, STN type, IPS type, FFS type, and VA type can be applied. The retardation film is used by attaching the substrate-side surface of the retardation film to the outer surface of the polarizing plate arranged on the viewing side of the liquid crystal display element. Therefore, it is preferable to employ a mode in which the substrate of the retardation film is made of TAC or an acrylic substrate and the substrate of the retardation film also functions as a protective film for the polarizing film.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

In the following examples, the weight average molecular weight Mw and number average molecular weight Mn of the polymer, the solution viscosity of the polymer solution, and the imidization rate of the polyimide were measured by the following methods. Necessary amounts of the raw material compounds and polymers used in the following examples were ensured by repeating the synthesis on the synthesis scale shown in the following synthesis examples as necessary.

[Polymer Weight Average Molecular Weight Mw and Number Average Molecular Weight Mn]
Mw and Mn are polystyrene conversion values measured by GPC under the following conditions.
Column: TSKgelGRCXLII manufactured by Tosoh Corporation
Solvent: N,N-dimethylformamide Temperature: 40°C
Pressure: 68kgf/ ^cm2
[Solution Viscosity of Polymer Solution]
The solution viscosity (mPa·s) of the polymer solution was measured at 25° C. using an E-type rotational viscometer.
[Imidization rate of polyimide]
After the imidized polymer was dried under reduced pressure at room temperature, it was dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. asked.
Imidation rate (%) = (1-A ¹ /A ² × α) × 100 (I)
(In formula (I), A ¹ is the peak area derived from protons of the NH group appearing near the chemical shift of 10 ppm, A ² is the peak area derived from other protons, and α is the precursor of the polymer (polyamic acid ) is the number ratio of other protons to one proton of the NH group.)

The compounds used in the examples are shown below. In addition, below, the compound represented by Formula (X) may be simply abbreviated as "compound (X)."

[Synthesis Example 1]
47.4 g (0.15 mol) of compound (a-1) and 52.6 g (0.15 mol) of compound (b-1) were dissolved in 566 g of N-methyl-2-pyrrolidone (NMP), C. for 6 hours to obtain a solution containing 15% by mass of polyamic acid. The weight average molecular weight Mw of the obtained polyamic acid was 45,000. After the reaction, the reaction solution was added dropwise to 3000 g of water to precipitate polyamic acid (resin). After filtration through a 100-mesh filter, the precipitate was washed with methanol and dried at 40° C. under reduced pressure for 15 hours to obtain 85 g of polyamic acid solid. Put 50 g of the obtained solid in a flask, add 340 g of water and 10 g (0.18 mol) of potassium hydroxide, stir at 20 ° C. for 12 hours to dissolve, and obtain a polyamic acid solution with a solid content concentration of 15% by mass. (PA-1) was obtained.

[Synthesis Example 2]
61.3 g (0.14 mol) of compound (a-2) and 38.7 g (0.14 mol) of compound (b-2) were dissolved in 566 g of NMP and reacted at 60° C. for 6 hours to obtain polyamic acid. A solution containing 15% by weight was obtained. The weight average molecular weight Mw of the resulting polyamic acid was 70,000. After the reaction, the reaction solution was added dropwise to 3000 g of water to precipitate polyamic acid (resin). After filtration through a 100-mesh filter, the precipitate was washed with methanol and dried at 40° C. under reduced pressure for 15 hours to obtain 92 g of polyamic acid solid. 50 g of the obtained solid is placed in a flask, 425 g of water and 25 g (0.30 mol) of sodium hydrogencarbonate are added, and dissolved by stirring at 20° C. for 12 hours to obtain a polyamic acid solution with a solid content concentration of 15% by mass. (PA-2) was obtained.

[Synthesis Example 3]
61.3 g (0.14 mol) of compound (a-2) and 48.1 g (0.14 mol) of compound (b-3) were dissolved in 566 g of NMP and reacted at 60° C. for 6 hours to obtain polyamic acid. A solution containing 15% by weight was obtained. The weight average molecular weight Mw of the resulting polyamic acid was 65,000. After the reaction, the reaction solution was added dropwise to 3000 g of water to precipitate polyamic acid (resin). After filtration through a 100 mesh filter, the precipitate was washed with methanol and dried at 40° C. under reduced pressure for 15 hours to obtain 80 g of polyamic acid solid. 50 g of the obtained solid was placed in a flask, 470 g of water and 33 g (0.14 mol) of cesium pivalate were added, and the mixture was stirred at 20° C. for 12 hours to dissolve the polyamic acid solution with a solid concentration of 15% by weight. (PA-3) was obtained.

[Synthesis Example 4]
19.61 g (0.1 mol) of cyclobutanetetracarboxylic dianhydride and 21.23 g (0.1 mol) of 4,4′-diamino-2,2′-dimethylbiphenyl were dissolved in 367.6 g of NMP and stirred at room temperature. for 6 hours. The reaction mixture was poured into a large excess of methanol to precipitate polyamic acid (resin). After filtration through a 100-mesh filter, the precipitate was washed with methanol and dried at 40° C. under reduced pressure for 15 hours to obtain 35 g of polyamic acid solid. Put 20 g of the obtained solid in a flask, add 200 g of water and 15 g (0.11 mol) of potassium carbonate, stir and dissolve at 20 ° C. for 12 hours, and obtain a polyamic acid solution (PA- 4) was obtained.

[Synthesis Example 5]
A polyamic acid solution with a solid content concentration of 15% by mass (PA-5 ).

[Synthesis Example 6]
224 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride, 54 g (0.5 mol) of p-phenylenediamine, and 260 g (0.5 mol) of cholestanyl 3,5-diaminobenzoate It was dissolved in 2900 g of NMP and reacted at 60° C. for 6 hours to obtain a polyamic acid solution with a solution viscosity of 320 mPa·s. 300 g of the resulting polymer solution was dropped into 3000 g of water to precipitate polyamic acid (resin). After filtration through a 100 mesh filter, the precipitate was washed with methanol and dried at 40° C. under reduced pressure for 15 hours to obtain 40 g of polyamic acid solid. 20 g of the obtained solid was placed in a flask, 130 g of water and 3 g (0.13 mol) of lithium hydroxide were added, and stirred at 20° C. for 12 hours to dissolve, resulting in a polyamic acid solution with a solid concentration of 15% by mass. (PA-6) was obtained.

[Synthesis Example 7]
224 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride, 108 g (1.0 mol) of p-phenylenediamine, and 7.8 g (0.015 mol) of cholestanyl 3,5-diaminobenzoate ) was dissolved in 3039 g of NMP and reacted at 60° C. for 6 hours to obtain a polyamic acid solution with a solution viscosity of 260 mPa·s. Next, 2700 g of NMP was added to the obtained polyamic acid solution, 396 g of pyridine and 306 g of acetic anhydride were added, and dehydration ring closure was carried out at 110° C. for 4 hours. After the imidization reaction, the solvent in the system was replaced with new γ-butyrolactone, and the solid content concentration was 9.0% by mass, the solution viscosity was 250 mPa s with a solid content concentration of 10% by mass, and the imidization rate was about 51%. 3,000 g of coalesced solution was obtained. 300 g of the resulting polymer solution was dropped into 3000 g of water to precipitate polyamic acid (resin). After filtration through a 100-mesh filter, the precipitate was washed with methanol and dried at 40° C. under reduced pressure for 15 hours to obtain 25 g of polyamic acid solid. 20 g of the obtained solid was placed in a flask, 130 g of water and 3 g (0.08 mol) of sodium hydroxide were added, and stirred at 20° C. for 12 hours to dissolve, giving a polyamic acid solution with a solid content concentration of 15% by mass. (PA-7) was obtained.

[Synthesis Example 8]
Synthesis was carried out in the same manner as in Synthesis Example 2 except that 30 g (0.30 mol) of triethylamine was used instead of sodium hydrogen carbonate, and a polyamic acid solution (PR-1) (solid content concentration: 15.8% by mass) was prepared. Obtained.
[Synthesis Example 9]
An acrylic copolymer aqueous solution (PR-2) was obtained according to the method described in paragraphs [0134] and [0150] of JP-A-2016-224151.
[Synthesis Example 10]
An aqueous polyamic acid solution (PR-3) was obtained according to the method described in paragraph [0041] of JP-A-08-087017.

[Example 1]
1. Preparation of liquid crystal aligning agent As a polymer component, distilled water (WT) was added as a solvent to the polyamic acid solution (PA-1) having a solid content concentration of 15% by mass obtained in Synthesis Example 1, and the solid content concentration was 3% by mass. It was prepared to be Then, the liquid crystal aligning agent (A-1) was prepared by filtering the obtained solution through a filter having a pore size of 1 μm.

2. Preparation of Optical Film On a triacetyl cellulose film, the liquid crystal aligning agent (A-1) prepared above was applied using a bar coater and baked in an oven at 120° C. for 2 minutes to give a film thickness of 0.1 μm. to form a coating film. Next, the coating film surface was irradiated with 10 mJ/cm ² of polarized ultraviolet light containing an emission line of 313 nm perpendicularly from the normal line of the base material surface using a Hg-Xe lamp and a Glan-Taylor prism to prepare a liquid crystal alignment film. . Then, a polymerizable liquid crystal (RMS03-013C, manufactured by Merck) was filtered through a filter with a pore size of 0.2 μm and applied to the surface of the liquid crystal alignment film using a bar coater. Subsequently, after baking for 1 minute in an oven set at 50° C., the polymerizable liquid crystal is irradiated with 1,000 mJ/cm ² of non-polarized ultraviolet rays containing an emission line of 365 nm using an Hg—Xe lamp to cure. let me The film thickness of the optically anisotropic film formed on the liquid crystal alignment film was 1.0 μm.

3. Evaluation of Liquid Crystal Alignment The liquid crystal alignment of the optical film obtained above was observed visually under crossed Nicols and with a polarizing microscope. "Good (A)" indicates that the liquid crystal alignment is visually observed to be good and no abnormal domains are observed by the polarizing microscope. A case in which this was observed was evaluated as "good (B)", and a case in which an abnormality in liquid crystal alignment was visually observed was evaluated as "bad (C)". As a result, in this Example 1, the liquid crystal orientation was evaluated as "fair (B)".

4. Evaluation of Transparency Transparency was evaluated by measuring the haze (HAZE) of the optical film produced above. Measurement was performed using a spectroscopic haze meter (manufactured by Tokyo Denshoku Co., Ltd.). A lower haze value means better transparency. "Good (A)" when the haze value was 2% or less, "Fair (B)" when the haze value was greater than 2% and 4% or less, and the haze value was greater than 4% In that case, it was judged as "defective (C)". In this Example 1, the transparency was "good (A)".

5. Evaluation of solvent resistance The liquid crystal aligning agent (A-1) prepared above was applied using a spinner on a glass substrate and prebaked on a hot plate at 120 ° C. for 2 minutes, and then the thickness of the formed coating film. was measured with a stylus type film thickness meter. Next, cyclopentanone was applied onto the formed coating film using a spinner, dried on a hot plate at 120° C. for 2 minutes, and the film thickness was measured again. At this time, the smaller the change in film thickness, the better the solvent resistance. "Good (A)" when the film thickness change rate is 3% or less, "Fair (B)" when the film thickness change rate is greater than 3% and 20% or less, and the film thickness change rate is When it was greater than 20%, it was judged to be "bad (C)". In this Example 1, the solvent resistance was "good (A)".

[Examples 2 to 8 and Comparative Examples 1 to 3]
Liquid crystal aligning agents (A-2) to (A-7), and ( R-1) to (R-3) were prepared respectively. When adding a solvent other than distilled water, considering the water brought in from the polyamic acid solutions prepared in Synthesis Examples 1 to 10, the final solvent composition was adjusted to the mass ratio shown in Table 1 below. did.
Moreover, it evaluated like Example 1 except having changed the following points in Example 1 using each obtained liquid crystal aligning agent.

For Examples 2 and 3 Various evaluations were performed in the same manner as in Example 1 except that the liquid crystal aligning agent (A-2) or (A-3) was used instead of the liquid crystal aligning agent (A-1). .
· Regarding Examples 4 and 5, the liquid crystal aligning agent (A-4) or (A-5) was used instead of the liquid crystal aligning agent (A-1), and the Hg-Xe lamp and Gran Taylor prism were used on the coating film surface. Various evaluations were performed in the same manner as in Example 1, except that 10,000 J/m ² of polarized ultraviolet light containing an emission line of 254 nm was irradiated from the normal line of the substrate surface.
・About Example 6 The liquid crystal aligning agent (A-6) was used instead of the liquid crystal aligning agent (A-1), the polarized ultraviolet irradiation to the coating film surface was eliminated, and RMS03-015 was used as the polymerizable liquid crystal. (manufactured by Merck) was used, and various evaluations were performed in the same manner as in Example 1.

・About Example 7 The liquid crystal aligning agent (A-1) was replaced with the liquid crystal aligning agent (A-7), and the coating film formed using the liquid crystal aligning agent was rubbed instead of the photo-alignment treatment. Various evaluations were performed in the same manner as in Example 1, except that the liquid crystal aligning ability was imparted by the treatment. The rubbing treatment was performed as follows. A rubbing machine having a roll wrapped with a rayon cloth is used to rub the surface of the coating film at a roll rotation speed of 400 rpm, a stage movement speed of 3 cm / sec, and a pile pushing length of 0.4 mm. It was ultrasonically cleaned in ultrapure water for 1 minute and dried in a 100° C. clean oven for 10 minutes.
Regarding Example 8 The liquid crystal aligning agent (A-4) was used instead of the liquid crystal aligning agent (A-1), and the coating film (liquid crystal alignment film) after irradiation with polarized ultraviolet rays was a 1% aqueous solution of strontium hydroxide. Various evaluations were carried out in the same manner as in Example 1, except that the sample was immersed in and passivated.

For Comparative Examples 1 and 2 Various evaluations were performed in the same manner as in Example 1 except that the liquid crystal aligning agent (R-1) or (R-2) was used instead of the liquid crystal aligning agent (A-1). .
・Regarding Comparative Example 3 In place of the liquid crystal aligning agent (A-7), the liquid crystal aligning agent (R-3) was used, and the coating film formed using the liquid crystal aligning agent was rubbed instead of the photo-alignment treatment. Various evaluations were performed in the same manner as in Example 1, except that the liquid crystal aligning ability was imparted by the treatment. The rubbing treatment was performed under the same conditions as in Example 7.

Abbreviations of solvents in Table 1 are as follows.
CHN: cyclohexanone PGME: propylene glycol monomethyl ether WT: distilled water MEOH: methanol THF: tetrahydrofuran NPA: n-propyl alcohol IPA: i-propyl alcohol

Various evaluation results of Examples 1 to 8 and Comparative Examples 1 to 3 are summarized in Table 2 below.

As is clear from Table 2, in Examples 1 to 8, the liquid crystal orientation, transparency, and solvent resistance were all evaluated as "A" or "B." In contrast, the comparative examples were inferior to the examples in both transparency and solvent resistance.

Claims (9)

A liquid crystal aligning agent containing water and a polymer having a partial structure represented by the following formula (1).

(In formula (1), R ¹ is a hydrogen atom or a monovalent organic group, X ¹ is a tetravalent organic group, and X ² is a divalent organic group. M ⁿ⁺ represents an alkali metal is a monovalent cation having m1 is 1 or 2, m2 is 0 or 1, and satisfies m1+m2=2.) Containing at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, a base having a typical metal element, and water ,
The liquid crystal aligning agent , wherein the base is a salt of an alkali metal and a weak acid . The liquid crystal aligning agent according to claim 1 or 2 , wherein the polymer has a photo-aligning group. A liquid crystal alignment film formed using the liquid crystal alignment agent according to any one of claims 1 to 3 . An optical film comprising the liquid crystal alignment film according to claim 4 . A liquid crystal device comprising the liquid crystal alignment film according to claim 4 . Mixing at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, a base having a typical metal element, and water ,
The method for producing a liquid crystal aligning agent , wherein the base is a salt of an alkali metal and a weak acid . A step of applying the liquid crystal aligning agent according to any one of claims 1 to 3 to each of a pair of substrates to form a coating film on the pair of substrates;
a step of performing a passivation treatment on the surfaces of the pair of substrates on which the coating film is formed;
A method for manufacturing a liquid crystal alignment film, comprising: A step of applying the liquid crystal aligning agent according to any one of claims 1 to 3 to each of a pair of substrates and irradiating light to form a liquid crystal alignment film;
A step of constructing a liquid crystal cell by arranging a pair of substrates on which the liquid crystal alignment film is formed so that the liquid crystal alignment films face each other with the liquid crystal layer interposed therebetween;
A method for producing an optical film, comprising: