KR20200067199A - Liquid crystal aligning agent, liquid crystal aligning film and liquid crystal display element - Google Patents

Abstract

It is a liquid crystal aligning agent containing at least one polymer and an organic solvent selected from a polyimide precursor that is a reactant of a tetracarboxylic acid derivative and a diamine and a polyimide that is an imide, and the organic solvent is component A: γ-buty At least one B component selected from loractone and γ-valerolactone: Contains at least one selected from dipropylene glycol dimethyl ether and diacetone alcohol, and the content of component A and component B is 25% by weight or less, respectively. , And the difference in content between component A and component B is 5% by weight or less.

Description

Liquid crystal aligning agent, liquid crystal aligning film and liquid crystal display element

The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film and a liquid crystal display device suitable for coating by an inkjet method (hereinafter referred to as inkjet coating).

A polyimide precursor, such as polyamic acid, or a liquid crystal aligning agent containing a solution of a soluble polyimide as a main component and calcined by firing a liquid crystal aligning agent as a main component is widely used. As a method of forming such a liquid crystal alignment film, inkjet coating has become the mainstream in place of conventional spin coating and flexographic printing.

Inkjet coating is a method in which fine droplets are dropped onto a substrate and formed into a film by diffusion of the liquid. By this method, efficient use of the liquid crystal aligning agent in the liquid crystal panel manufacturing process becomes possible, and the production efficiency of the liquid crystal panel can be improved, and the cost of the liquid crystal panel accompanying it can be reduced.

The liquid crystal aligning agent used for inkjet coating is required to have a small film thickness non-uniformity inside the coating surface, a high film-forming precision at the periphery of the coating, and the like. At the same time, it is also important that the organic solvent in the liquid crystal aligning agent does not damage the inkjet head or the peripheral member when ejected from the inkjet device.

In order to achieve the above-mentioned various demands, a liquid crystal aligning agent for inkjet coating by an appropriate combination of various solvents has been proposed (refer to Patent Documents 1 and 2), but with the recent increase in size and size of liquid crystal display elements, additional Improvement of characteristics is desired.

Japanese patent application 2013-507817 Japanese Patent Application 2014-529512

In view of the above background, the present invention aims to provide a liquid crystal aligning agent that is optimal for inkjet coating by improving various properties required for inkjet coating.

The inventors repeatedly conducted various studies to achieve the above object, and found that the liquid crystal aligning agent according to the following configuration is optimal for achieving the above object, thereby completing the present invention.

In this way, this invention is based on said knowledge and has the following summary.

1. A liquid crystal aligning agent containing at least one polymer and an organic solvent selected from a polyimide precursor which is a reactant of a tetracarboxylic acid derivative and a diamine and a polyimide that is an imide thereof, wherein the organic solvent is

Component A: At least one selected from γ-butyrolactone and γ-valerolactone

Component B: Dipropylene glycol dimethyl ether

The content of A component and B component is 25 weight% or less, respectively, and the content difference of A component and B component is 5 weight% or less, The liquid crystal aligning agent characterized by the above-mentioned.

By using the liquid crystal aligning agent of the present invention, when used for inkjet coating, it is possible to obtain a liquid crystal aligning film having a small film thickness non-uniformity inside the coating surface and having a high film forming precision at the periphery of the coating, and when the liquid crystal aligning agent is discharged from the ink jet apparatus , It does not damage the inkjet head or the peripheral member, and consequently, it becomes possible to contribute to the stability of manufacturing the liquid crystal display element.

Hereinafter, various requirements of the present invention will be described in detail.

<Organic solvent and its composition>

The liquid crystal aligning agent of this invention contains the following A and B components as an organic solvent.

Component A: At least one selected from γ-butyrolactone and γ-valerolactone

Component B: Dipropylene glycol dimethyl ether

The organic solvent of component A dissolves the polymer contained in the liquid crystal aligning agent of the present invention, but at the same time, does not adversely affect the inkjet head or peripheral members of the inkjet coating device. As component A, γ-butyrolactone is preferable.

The solvent of component B is one in which the diffusibility when the liquid crystal aligning agent of the present invention is applied onto a substrate or film is improved.

Content of A component and B component is 25 weight% or less, respectively, and content difference of A component and B component is 5 weight% or less.

Moreover, when it contains at least 1 sort(s) selected from N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone and N-butyl-2-pyrrolidone as a C component further, it is a soluble viewpoint. Is preferred.

The organic solvent of component C is a component that dissolves the polymer contained in the liquid crystal aligning agent of the present invention. Preferable specific examples include N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone.

Moreover, when using a C component, content is 35 weight% or less with respect to the weight of the whole liquid crystal aligning agent, and 30 weight% or less is more preferable.

<polymer>

The polymer contained in the liquid crystal aligning agent of the present invention is at least one polymer selected from a polyimide precursor that is a reactant of a tetracarboxylic acid derivative and a diamine and a polyimide that is an imide thereof.

Although the structure of the said polymer is not specifically limited, In addition to the characteristic of the liquid crystal aligning agent obtained, the tetracarboxylic-acid derivative and diamine mentioned later can be arbitrarily selected, Especially, it contains the side chain structure of following formula [1-1] The polymer to be used is preferable from the viewpoint of solubility and the like.

[Formula 1]

Formula [1-1] in, Y ¹ and Y ³ are, each independently, a single _{bond, - (CH 2) a -} (a is an integer (整數) of 1 ~ 15), -O-, -CH 2 O It represents at least 1 sort(s) selected from the group which consists of -, -COO- and -OCO-.

Y ² represents a single bond or -(CH ₂ ) _b- (b is an integer from 1 to 15) (however, when Y ¹ or Y ³ is a single bond, -(CH ₂ ) _a -, Y ² is Is a single bond, and Y ¹ is at least one member selected from the group consisting of -O-, -CH ₂ O-, -COO- and -OCO-, and/or Y ³ is -O-, -CH ₂ O- , When at least one member selected from the group consisting of -COO- and -OCO-, Y ² is a single bond or -(CH ₂ ) _b -).

Y ⁴ represents at least one divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, or a divalent organic group having 17 to 51 carbon atoms having a steroid skeleton, and any hydrogen on the cyclic group The atom may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom.

Y ⁵ represents at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocycle, and any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms The group may be substituted with a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom.

Y ⁶ is at least selected from the group consisting of a C1-C18 alkyl group, a C2-C18 alkenyl group, a C1-C18 fluorine-containing alkyl group, a C1-C18 alkoxy group and a C1-C18 fluorine-containing alkoxy group. 1 type is shown. n represents the integer of 0-4.

In order to introduce the said side chain structure into a polymer, the method using what introduce|transduced the said side chain structure to the tetracarboxylic-acid derivative or diamine which is a material of a polymer is mentioned. Especially, it is preferable to use the diamine which introduce|transduced the said side chain structure from a viewpoint of ease of synthesis, etc.

The following formula (S1-1)-(S1-22) are mentioned as a preferable specific example of the said side chain structure.

[Formula 2]

Moreover, in the manufacturing process of a liquid crystal display element, when it has a process, such as ultraviolet irradiation, it is preferable to introduce the photoreactive side chain which causes photoreaction with ultraviolet rays of a specific wavelength.

As a photoreactive side chain, the side chain structure of following formula [VII] is mentioned. The side chain structure of Formula [VII] has a radical generating structure. In the radical generating structure, radicals are generated by decomposition by ultraviolet irradiation.

[Formula 3]

In the formula [VII], Ar represents at least one aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene and biphenylene, and the hydrogen atom of their ring may be substituted with a halogen atom. Ar, which is attached to carbonyl, is involved in the absorption wavelength of ultraviolet light, and therefore, when it is long-wavelength, a structure having a long conjugated length such as naphthylene or biphenylene is preferable. On the other hand, when Ar has a structure such as naphthylene or biphenylene, solubility may be deteriorated, and in this case, the difficulty of synthesis increases. When the wavelength of ultraviolet light is in the range of 250 nm to 380 nm, Ar is preferably a phenyl group because sufficient properties can be obtained even if it is a phenyl group.

In the above Ar, a substituent may be formed as the aromatic hydrocarbon group. As an example of the substituent here, an electron donating organic group such as an alkyl group, a hydroxyl group, an alkoxy group or an amino group is preferable.

Moreover, in said Formula [VII], R<_1> and R<_2> respectively independently represent a C1-C10 alkyl group, an alkoxy group, a benzyl group, or a phenethyl group. In the case of an alkyl group or an alkoxy group, a ring may be formed by R ¹ and R ² .

Further, in the formula [VII], T ₁ and T ₂ are each independently a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ Represents a bonding group of O-, -N(CH ₃ )-, -CON(CH ₃ )- or -N(CH ₃ )CO-.

Moreover, in Formula [VII], S represents a C1-C20 alkylene group substituted by the single bond, unsubstituted, or a fluorine atom. -CH ₂ -or -CF ₂ -of the alkylene group here may be optionally substituted with -CH=CH-, or when any of the groups exemplified below are not adjacent to each other, these groups may be substituted; -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbon ring, divalent heterocycle.

Moreover, in Formula [VII], Q represents the structure chosen from following formula (1d).

[Formula 4]

In the formula (1d), R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ₃ represents -CH ₂ -, -NR-, -O-, or -S-.

Moreover, in said Formula [VII], Q is preferably an electron donating organic group, and an alkyl group, a hydroxyl group, an alkoxy group, an amino group, etc. as illustrated in the example of said Ar are preferable. When Q is an amino derivative, a hydroxyl group or an alkoxy group is more preferable because a problem such as formation of a salt may occur during polymerization of polyamic acid, which is a precursor of polyimide, to a carboxylic acid group and an amino group. .

<tetracarboxylic acid derivative>

The polymer contained in the liquid crystal aligning agent of the present invention is at least one polymer selected from a polyimide precursor obtained from the reaction of a tetracarboxylic acid derivative with a diamine and a polyimide thereof. Below, the specific example and manufacturing method of the material used are explained in full detail.

Tetracarboxylic acid derivatives used in the production of polyimide precursors include not only tetracarboxylic dianhydride, but also derivatives thereof, tetracarboxylic acid, tetracarboxylic acid dihalide compound, tetracarboxylic acid dialkyl ester, and tetracar And carboxylic acid dialkyl ester dihalides.

Especially as a tetracarboxylic-acid derivative, it is preferable to represent with following formula (3).

[Formula 5]

In Formula (3), the structure of X ₁ is not particularly limited. The following formula (X1-1)-(X1-42) is mentioned as a specific example. Preferred are (X1-1), (X1-2), (X1-5), (X1-7), (X1-8), (X1-10), (X1-11), (X1-26) , (X1-27), (X1-33), (X1-38), (X1-40).

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

In Formulas (X1-1) to (X1-4), R ₃ to R ₂₃ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or 2 to 2 carbon atoms. It is an alkynyl group of 6, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group. From the viewpoint of liquid crystal alignment, R ₃ to R ₂₃ are preferably a hydrogen atom, a halogen atom, a methyl group, or an ethyl group, and preferably a hydrogen atom or a methyl group.

The following formula (X1-1-1)-(X1-1-6) is mentioned as a specific example of Formula (X1-1). (X1-1-1) and (X1-1-2) are particularly preferred from the viewpoint of liquid crystal alignment and polymerization reactivity.

[Formula 12]

<diamine>

The diamine used for the production of the polyimide precursor is represented by the following formula (4).

[Formula 13]

In the formula (4), A ₁ and A ₂ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkynyl group having 2 to 5 carbon atoms.

The structure of the formula (4) is not particularly limited. As a preferable structure, the diamine containing the side chain structure of Formula [1-1] mentioned above is mentioned. (Y-178), (Y-180), (Y-181) is mentioned as a specific example of these.

In addition, the use of diamines having any structure is possible. The following (Y-1)-(Y-177) are mentioned as a specific example.

(Y-27), (Y-28), (Y-38), (Y-71), (Y) in terms of ease of production of the polyimide precursor, stability of the liquid crystal aligning agent, properties as a liquid crystal aligning film, etc. -72), (Y-76), (Y-77), (Y-80), (Y-81), (Y-82), (Y-158), (Y-159), (Y-160) ), (Y-161), (Y-169) to (Y-188) are preferred.

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

[Formula 23]

[Formula 24]

[Formula 25]

[Formula 26]

[Formula 27]

[Formula 28]

[Formula 29]

[Formula 30]

[Formula 31]

[Formula 32]

In the formula, Me represents a methyl group, and R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms.

[Formula 33]

<polyamic acid>

The polyamic acid which is a polyimide precursor used for this invention can be manufactured with the method shown below. Specifically, tetracarboxylic dianhydride and diamine are reacted at -20°C to 150°C, preferably 0°C to 50°C for 30 minutes to 24 hours, preferably 1 to 12 hours in the presence of an organic solvent. Can be synthesized.

The organic solvent used for the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone from the solubility of monomers and polymers. You may mix and use the above. The concentration of the polymer is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass, from the viewpoint that the precipitation of the polymer does not occur easily and a high molecular weight body is easily obtained.

The polyamic acid obtained as described above can be recovered by depositing a polymer by injecting the reaction solution into a poor solvent while stirring well. Moreover, the powder of the purified polyamic acid can be obtained by carrying out precipitation several times, washing with a poor solvent, and then drying at room temperature or by heating. The poor solvent is not particularly limited, and examples thereof include water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.

<polyamic acid ester>

The polyamic acid ester which is one of the polyimide precursors used in the present invention can be produced by the methods (I), (II) or (III) shown below.

(I) When manufacturing with polyamic acid

The polyamic acid ester can be synthesized by esterifying a polyamic acid obtained from tetracarboxylic dianhydride and diamine. Specifically, the polyamic acid and the esterifying agent are synthesized by reacting at -20°C to 150°C, preferably 0°C to 50°C, in the presence of an organic solvent for 30 minutes to 24 hours, preferably 1 to 4 hours. Can be.

As an esterifying agent, it is preferable that it can be easily removed by purification, N,N-dimethylformamide dimethylacetal, N,N-dimethylformamide diethyl acetal, N,N-dimethylformamide dipropyl acetal, N,N-dimethylformamidedineopentylbutylacetal, N,N-dimethylformamidedi-t-butylacetal, 1-methyl-3-p-tolyltriagene, 1-ethyl-3-p-tolyltriagene , 1-propyl-3-p-tolyltrigen, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride, and the like. The amount of the esterifying agent used is preferably 2 to 6 molar equivalents to 1 mole of repeating units of the polyamic acid.

The solvent used for the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone from the solubility of the polymer. You may use it. The concentration of the polymer in the reaction solution is preferably from 1 to 30% by mass, and more preferably from 5 to 20% by mass, from the viewpoint that precipitation of the polymer does not occur easily and a high molecular weight body is easily obtained.

(II) When prepared by reaction of tetracarboxylic acid diester dichloride and diamine

The polyamic acid ester can be produced from tetracarboxylic acid diester dichloride and diamine. Specifically, tetracarboxylic acid diester dichloride and diamine are present at -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 to It can be synthesized by reacting for 4 hours.

As the base, pyridine, triethylamine, 4-dimethylaminopyridine, or the like can be used, but pyridine is preferable for the reaction to proceed gently. The amount of the base used is an amount that can be easily removed, and from the viewpoint of easily obtaining a high molecular weight body, 2 to 4 times mole is preferable with respect to the tetracarboxylic acid diester dichloride.

The solvent used for the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone from the solubility of monomers and polymers, and these may be used alone or in combination of two or more. The polymer concentration in the reaction solution is preferably from 1 to 30% by mass, more preferably from 5 to 20% by mass, from the viewpoint that the precipitation of the polymer does not occur easily and a high molecular weight body is easily obtained. Moreover, in order to prevent the hydrolysis of the tetracarboxylic acid diester dichloride, the solvent used for the synthesis of the polyamic acid ester is desirably dehydrated as much as possible, and it is preferable to prevent the incorporation of outside air in a nitrogen atmosphere.

(III) When prepared by reaction of tetracarboxylic acid diester and diamine

The polyamic acid ester can be produced by polycondensing a tetracarboxylic acid diester and diamine. Specifically, tetracarboxylic acid diester and diamine are present in a condensing agent, a base, and an organic solvent at 0°C to 150°C, preferably 0°C to 100°C, for 30 minutes to 24 hours, preferably 3 It can be produced by reacting for 15 hours.

Examples of the condensing agent include triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N,N'-carbonyldiimidazole, and dimethoxy-1 ,3,5-triadinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluraniumtetrafluoroborate, O-(benzotriazole- 1-yl)-N,N,N',N'-tetramethyluranium hexafluorophosphate, diphenyl (2,3-dihydro-2-thioxo-3-benzooxazolyl)phosphonate, etc. can be used. have. The amount of the condensing agent added is preferably 2 to 3 times the mole relative to the tetracarboxylic acid diester.

As the base, tertiary amines such as pyridine and triethylamine can be used. The amount of the base is preferably 2 to 4 times the molar amount of the diamine component from the viewpoint of easy removal and high molecular weight.

Moreover, in the said reaction, reaction advances efficiently by adding a Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferred. The amount of Lewis acid added is preferably 0 to 1.0 times the mole relative to the diamine component.

Among the above-mentioned three polyamic acid ester production methods, the production method of the above (1) or (2) is particularly preferred because a high molecular weight polyamic acid ester is obtained.

The solution of the polyamic acid ester obtained as described above can be precipitated by injecting it into a poor solvent while stirring well. Precipitation is performed several times, followed by washing with a poor solvent, followed by drying at room temperature or by heating to obtain a purified polyamic acid ester powder. The poor solvent is not particularly limited, and examples thereof include water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.

<polyimide>

The polyimide used in the present invention can be produced by imidizing the polyamic acid or polyamic acid ester. The polyimide imidation rate used in the present invention is not limited to 100%. From the viewpoint of electrical properties, 20 to 99% is preferable. When producing a polyimide from a polyamic acid ester, chemical imidation is simple by adding a basic catalyst to the polyamic acid ester solution or a polyamic acid solution obtained by dissolving a polyamic acid ester resin powder in an organic solvent. Chemical imidation is preferable because the imidation reaction proceeds at a relatively low temperature and the molecular weight of the polymer does not easily decrease in the course of imidization.

Chemical imidation can be performed by stirring the polyamic acid or polyamic acid ester to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride. As an organic solvent, the solvent used at the time of the polymerization reaction mentioned above can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine is preferable because it has basicity suitable for advancing the reaction. Further, examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among these, acetic anhydride is preferred because purification after completion of the reaction becomes easy.

The temperature at the time of performing the imidization reaction is -20°C to 120°C, for example, preferably 0°C to 100°C, and the reaction time can be carried out at 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 mole times of the amic acid group, preferably 2 to 20 mole times, and the amount of the acid anhydride is 1 to 50 mole times of the amic acid group, preferably 3 to 30 mole times. The imidation rate of the obtained polymer can be controlled by adjusting the catalyst amount, temperature, and reaction time.

Since the added catalyst or the like remains in the solution after the imidation reaction of the polyamic acid ester or polyamic acid, the obtained imidized polymer is recovered by means described below, redissolved with an organic solvent, and the liquid crystal of the present invention. It is preferable to use it as an alignment agent.

The solution of the polyimide obtained as described above can be precipitated by injecting it into a poor solvent while stirring well. Precipitation is performed several times, followed by washing with a poor solvent, followed by drying at room temperature or by heating to obtain a purified polyamic acid ester powder.

The poor solvent is not particularly limited, and examples thereof include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene.

<liquid crystal aligning agent>

The liquid crystal aligning agent of the present invention has the form of a solution in which a polymer containing a specific polymer is dissolved in an organic solvent containing a specific solvent. The molecular weight of the polyimide precursor and polyimide described in the present invention is preferably 2,000 to 500,000 as a weight average molecular weight, more preferably 5,000 to 300,000, and even more preferably 10,000 to 100,000. Moreover, the number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and still more preferably 5,000 to 50,000.

The concentration of the polymer of the liquid crystal aligning agent used in the present invention can be appropriately changed depending on the setting of the thickness of the coating film to be formed, but is preferably 1% by weight or more from the viewpoint of forming a uniform and defect-free coating film. In terms of storage stability, 10% by weight or less is preferable.

<Other solvents>

The solvent in the liquid crystal aligning agent of this invention contains A component and B component mentioned above, and if it further contains C component, it is preferable to contain other solvents. As other solvents, a solvent for dissolving a polyimide precursor and a polyimide (also referred to as a good solvent) or a solvent for improving the coatability and surface smoothness of the liquid crystal alignment film when a liquid crystal aligning agent is applied (also called a poor solvent) Is preferably used. Below, although the specific example of another solvent is given, it is not limited to these examples.

As a specific example of a good solvent, 1,3-dimethylimidazolidinone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropanamide or 4-hydroxy-4-methyl-2-pentanone.

As a specific example of a poor solvent, 1-butoxy-2-propanol, 2-butoxy-1-propanol, 2-propoxyethanol, 2-(2-propoxyethoxy)ethanol, 1-propoxy-2 -Propanolethanol, 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-methylcyclohexane All, 3-methylcyclohexanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2, 3-butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol Dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3- Pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol Diacetate, propylene carbonate, ethylene carbonate, 2-(methoxymethoxy)ethanol, butyl cellosolve, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2-(hexyloxy)ethanol, furfuryl alcohol, Diethylene glycol, propylene glycol, 1-(butoxyethoxy)propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene Glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate Diethylene glycol monoethyl ether acetate, propylene glycol diacetate, diisopentyl ether, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, triethylene glycol, Triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate , 3-ethyl ethoxypropionate, 3-methoxypropionate ethyl, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl, 3-methoxypropionic acid butyl, lactic acid methyl ester, lactic acid ethyl ester, And lactic acid n-propyl ester, lactic acid n-butyl ester, lactic acid isoamyl ester, diisobutyl ketone, ethyl carbitol, and the like.

Moreover, you may use the solvent represented by the following formula as a poor solvent.

[Formula 34]

R ₂₄ and R ₂₅ are each a linear or branched alkyl group having 1 to 8 carbon atoms. However, R ₂₄ + R ₂₅ is an integer greater than 3.

Moreover, as a poor solvent, when the solubility of the polyimide precursor and polyimide contained in a liquid crystal aligning agent is high in the solvent, you may use the solvent represented by the following [D-1]-Formula [D-3]. .

[Formula 35]

In formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms, in formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms, and in formula [D-3], D ³ Represents a C1-C4 alkyl group.

Moreover, the liquid crystal aligning agent of this invention is at least 1 sort(s) of substituent chosen from the group which consists of a crosslinkable compound which has an epoxy group, an isocyanate group, an oxetane group, or a cyclocarbonate group, a hydroxyl group, a hydroxyalkyl group, and a lower alkoxyalkyl group. It may contain the crosslinkable compound which has, or the crosslinkable compound which has a polymerizable unsaturated bond.

As the crosslinkable compound, various known compounds can be used depending on the purpose.

As a crosslinkable compound which has an epoxy group, bisphenol acetone glycidyl ether, phenol novolac epoxy resin, cresol novolac epoxy resin, triglycidyl isocyanurate, tetraglycidyl amino diphenylene, tetra, for example Glycidyl-m-xylenediamine, tetraglycidyl-1,3-bis(aminoethyl)cyclohexane, tetraphenylglycidyl ether ethane, triphenylglycidyl ether ethane, bisphenolhexafluoroacetdiglyc Cydyl ether, 1,3-bis(1-(2,3-epoxypropoxy)-1-trifluoromethyl-2,2,2-trifluoromethyl)benzene, 4,4-bis(2, 3-epoxypropoxy)octafluorobiphenyl, triglycidyl-p-aminophenol, tetraglycidylmethazylenediamine, 2-(4-(2,3-epoxypropoxy)phenyl)-2-(4 -(1,1-bis(4-(2,3-epoxypropoxy)phenyl)ethyl)phenyl)propane or 1,3-bis(4-(1-(4-(2,3-epoxypropoxy)) And phenyl)-1-(4-(1-(4-(2,3-epoxypropoxy)phenyl)-1-methylethyl)phenyl)ethyl)phenoxy)-2-propanol.

Specifically, the crosslinkable compound having an oxetane group includes crosslinkable compounds represented by formulas [4a] to [4k] shown on pages 58 to 59 of WO2011/132751 (published on October 27, 2011). Can be.

As a crosslinkable compound which has a cyclocarbonate group, specifically, it is represented by Formula [5-1]-Formula [5-42] published on pages 76-82 of international publication WO2012/014898 (2012.2.2 publication). And crosslinkable compounds.

As a crosslinkable compound which has at least 1 type of substituent selected from the group which consists of a hydroxyl group and an alkoxyl group, Specifically, it is published on pages 62-66 of WO2011/132751 (published on October 27, 2011). And crosslinkable compounds of formulas [6-1] to [6-48].

Among the crosslinkable compounds, the following compounds are particularly preferably used.

[Formula 36]

[Formula 37]

The content of the crosslinkable compound is preferably 0.1 to 150 parts by mass relative to 100 parts by mass of all polymer components. Especially, 0.1-100 mass parts is preferable and 1-50 mass parts is more preferable for a crosslinking reaction to advance and to express a desired effect.

The liquid crystal aligning agent of this invention can contain the compound which improves the uniformity and surface smoothness of the film thickness of a liquid crystal aligning film when apply|coating a liquid crystal aligning agent.

Fluorine-based surfactants, silicone-based surfactants, and non-ionic surfactants are mentioned as compounds that improve the uniformity and surface smoothness of the film thickness of the liquid crystal alignment film.

The surfactant is used in an amount of preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of all the polymer components contained in the liquid crystal aligning agent.

<Liquid crystal alignment film, liquid crystal display element>

The liquid crystal aligning film of this invention is a film obtained by apply|coating said liquid crystal aligning agent to a board|substrate, and drying and baking. 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 a glass substrate, a silicon nitride substrate, an acrylic substrate, or a polycarbonate substrate can also be used. At this time, when a substrate on which an ITO electrode or the like for driving a liquid crystal is formed is used, it is preferable from the viewpoint of simplifying the process. Further, in the reflective liquid crystal display element, a silicon wafer or the like may be used as long as it is a substrate on one side, and a material that reflects light such as aluminum can also be used for the electrode in this case.

The coating method of the liquid crystal aligning agent is generally industrially performed by screen printing, offset printing, flexo printing, inkjet method or the like, and other coating methods include dip method, roll coater method, and slit coater method. , Spinner method or spray method is known.

After the liquid crystal aligning agent is applied onto the substrate, the solvent can be evaporated to form a liquid crystal alignment film by heating means such as a hot plate, a heat cycle oven, or an IR (infrared) type oven. Any temperature and time can be selected for the drying and firing steps after applying the liquid crystal aligning agent. Usually, conditions for firing at 50 to 120°C for 1 to 10 minutes, and then for firing at 150 to 300°C for 5 to 120 minutes are mentioned to sufficiently remove the contained solvent. When the thickness of the liquid crystal alignment film after firing is too thin, reliability of the liquid crystal display element may be lowered, so 5 to 300 nm is preferable, and 10 to 200 nm is more preferable.

The liquid crystal aligning agent of this invention can be used as a liquid crystal aligning film, after apply|coating and baking on a board|substrate, and performing an alignment process by rubbing process, photo-alignment process, etc., and without an alignment process in a vertical alignment use etc. As an orientation treatment such as rubbing treatment or photo-alignment treatment, a known method or apparatus can be used.

As an example of a method for manufacturing a liquid crystal cell, a liquid crystal display element having a passive matrix structure will be described as an example. Further, a liquid crystal display element having an active matrix structure in which switching elements such as a TFT (Thin Film Transistor) are formed in each pixel portion constituting the image display may be used.

Specifically, a transparent glass substrate is prepared, a common electrode is formed on one substrate, and a segment electrode is formed on the other substrate. These electrodes can be, for example, ITO electrodes, and are patterned to display desired images. Subsequently, an insulating film is formed on each substrate by covering the common electrode and the segment electrode. The insulating film can be, for example, a SiO ₂ -TiO ₂ film formed by a sol-gel method.

Next, a liquid crystal alignment film is formed on each of the substrates, and the other substrates are superimposed on one substrate with the liquid crystal alignment film surfaces facing each other, and the periphery is bonded with a sealing agent. In order to control the substrate gap in the sealing agent, it is usually preferable to mix a spacer, and to spread the spacer for controlling the substrate gap in the in-plane portion where the sealing agent is not formed. An opening capable of filling the liquid crystal from the outside is formed in a part of the sealing agent. Subsequently, the liquid crystal material is injected into the space surrounded by the two substrates and the sealing agent through the opening formed in the sealing agent, and then the opening is sealed with an adhesive. For the injection, a vacuum injection method may be used, or a method using a capillary phenomenon in the atmosphere may be used. The liquid crystal material may be either a positive type liquid crystal material or a negative type liquid crystal material, but a preferred type is a negative type liquid crystal material. Next, a polarizing plate is installed. Specifically, a pair of polarizing plates are affixed to the surface opposite to the liquid crystal layer of the two substrates.

Example

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these. The symbol of the compound in the following and the measuring method of each characteristic are as follows.

<tetracarboxylic dianhydride>

CBDA: 1,2,3,4-cyclobutanetetracarboxylic acid anhydride

BODA: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride

DSDA: 3,3',4,4'-diphenylsulfonetetracarboxylic acid anhydride

PMDA: pyromellitic anhydride

<diamine>

DA-1: p-phenylenediamine

DA-2: 4,4-diaminodiphenylmethane

DA-3: 3,5-diaminobenzoic acid

DA-4: 3,5-diamino-N-(pyridin-3-ylmethyl)benzamide

DA-5: 4,4'-[isopropylidenebis(p-phenyleneoxy)]dianiline

DA-6: Diamine of the following formula DA-6

DA-7: 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone

DA-8: 1,3-diamino-4-[4-(trans-4-n-heptylcyclohexyl)phenoxy]benzene

DA-9: 1,3-diamino-4-[trans-4-[trans-4-(pentylcyclohexyl)-cyclohexyl]phenoxy]benzene

<Structure of DA-1 to DA-9>

[Formula 38]

<additive>

TM-BIP-A: 2,2'-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane

<Organic solvent>

NMP: 1-methyl-2-pyrrolidone

NEP: 1-ethyl-2-pyrrolidone

GBL: γ-butyrolactone

BCS: Butyl Cellosolve

PB: 1-butoxy-2-propanol

DME: Dipropylene glycol dimethyl ether

DIBK: diisobutyl ketone

In Examples, the molecular weight and the imidation rate of polyamic acid and polyimide were evaluated as follows.

<Molecular weight measurement>

As the molecular weight of the polyamic acid and polyimide, a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) manufactured by Showa Electric Works and a column manufactured by Shodex (KD-803, KD-805) were used. Measurement conditions are as follows.

Column temperature: 50 ℃

Eluent: N,N'-dimethylformamide (Additive: Lithium bromide-hydrate (LiBrH2O) is 30 mmol/L, phosphoric anhydride (o-phosphoric acid) is 30 mmol/L, tetrahydrofuran (THF ) 10 ml/ℓ)

Flow rate: 1.0 ml/min

Standard sample for calibration curve preparation: TSK standard polyethylene oxide (molecular weights about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weights about 12,000, 4,000, 1,000) manufactured by Polymer Laboratories.

<Measurement of imidation rate>

20 mg of the polyimide powder was placed in an NMR sample tube (Kusano Scientific Co., Ltd., NMR sampling tube standard φ5), and 0.53 mL of deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixture) was added, and ultrasonication was performed. Was added to dissolve completely. About this solution, 500 MHz of proton NMR was measured using the NMR meter (JNW-ECA500) manufactured by Nippon Electronic Datum. The imidation rate is determined by using a proton derived from a structure that does not change before and after imidization as a reference proton, and the peak integration value of this proton and the proton peak integration derived from the NH group of the amide acid appearing at about 9.0 to 11.0 ppm. It was calculated|required by following formula (1) using a value.

Imidation rate (%) = (1-α·x/y) × 100. (One)

In the formula (1), x is a proton peak integrated value derived from NH group of amic acid, y is a peak integrated value of reference proton, α is amic acid in the case of polyamic acid (imidation rate is 0%) The ratio of the number of reference protons to one of the NH group protons.

<Synthesis Example 1>

BODA (22.27 g, 89 mmol), DA-7 (14.70 g, 44.5 mmol), DA-4 (12.94 g, 53.4 mmol), DA-9 (19.34 g, 44.5 mmol), DA-8 ( 13.55 g, 35.6 mmol) were mixed in NMP (331.2 g), reacted at 60°C for 3 hours, then CBDA (16.93 g, 86.3 mmol) and NMP (67.2 g) were added, and at 40°C for 15 hours. The reaction was performed to obtain a polyamic acid solution (a). The number average molecular weight of this polyamic acid solution (a) was 22,000, and the weight average molecular weight was 58,000. NMP was added to this polyamic acid solution (a) (498.13 g), and the content of the polyamic acid solution (a) was diluted to 10 mass%, followed by acetic anhydride (90.87 g) and pyridine (28.16 g) as imidization catalysts. ) Was added and reacted at 70°C for 3.5 hours. This reaction solution was poured into methanol (5,000 mL), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide (A). The imidation ratio of this polyimide (A) was 72%.

<Synthesis Example 2>

BODA (23.02 g, 92 mmol), DA-3 (14.0 g, 92 mmol), DA-5 (22.66 g, 55.2 mmol), DA-8 (14.01 g, 36.8 mmol) NMP (294.73 g) ), and reacted at 60° C. for 1 hour, then CBDA (6.68 g, 34.0 mmol) and NMP (26.7 g) were added and reacted at 20° C. for 1 hour, followed by DSDA (19.78 g, 55.2 mmol) ) And NMP (79.11 g) were added and reacted at 40°C for 2 hours to obtain a polyamic acid solution (b). The number average molecular weight of this polyamic acid solution (b) was 17,000, and the weight average molecular weight was 45,000. After adding NMP to this polyamic acid solution (b) (500.69 g), the content of the polyamic acid solution (b) was diluted to 6.5 mass%, followed by acetic anhydride (93.93 g) and pyridine (72.77 g) as the imidization catalyst. ) Was added and reacted at 75°C for 3.5 hours. This reaction solution was poured into methanol (5,000 mL), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide (B). The imidation ratio of this polyimide (B) was 74%.

<Synthesis Example 3>

BODA (25.02 g, 100 mmol), DA-1 (8.65 g, 80 mmol), DA-6 (6.83 g, 20 mmol), DA-8 (38.6 g, 100 mmol) with NMP (214.2 g ), and reacted at 60°C for 3 hours, CBDA (19.61 g, 100 mmol) and NMP (178.5 g) were added, and reacted at 40°C for 15 hours to obtain a polyamic acid solution (c). The number average molecular weight of this polyamic acid solution (c) was 23,000, and the weight average molecular weight was 60,000. After adding NMP to this polyamic acid solution (c) (450.0 g), the content of the polyamic acid solution (a) was diluted to 10% by mass, followed by acetic anhydride (103.6 g) and pyridine (32.11 g) as imidization catalysts. ) Was added and reacted at 70°C for 3.5 hours. This reaction solution was poured into methanol (3,600 mL), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide (C). The imidation ratio of this polyimide (C) was 69%.

<Synthesis Example 4>

BODA (25.02 g, 100 mmol), DA-7 (6.60 g, 20 mmol), DA-2 (23.79 g, 120 mmol), DA-9 (26.1 g, 60 mmol) NMP (225.9 g) ), and reacted at 60°C for 3 hours, CBDA (19.61 g, 100 mmol) and NMP (178.5 g) were added, and reacted at 40°C for 15 hours to obtain a polyamic acid solution (d). The number average molecular weight of this polyamic acid solution (d) was 24,000, and the weight average molecular weight was 62,000. After adding NMP to this polyamic acid solution (d) (450.0 g), the content of the polyamic acid solution (d) was diluted to 10 mass%, followed by acetic anhydride (90.9 g) and pyridine (28.17 g) as the imidization catalyst. ) Was added and reacted at 70°C for 3.5 hours. This reaction solution was poured into methanol (3,600 mL), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide (D). The imidation ratio of this polyimide (D) was 73%.

<Synthesis Example 5>

BODA (25.02 g, 100 mmol), DA-3 (12.17 g, 80 mmol), DA-4 (14.53 g, 60 mmol), DA-8 (22.83 g, 60 mmol) NMP (198.17 g) ), and reacted at 60°C for 3 hours, and then PMDA (8.72 g, 40 mmol) and NMP (34.9 g) were added and reacted at 40°C for 3 hours. Finally, CBDA (11.76 g, 60 mmol) and NMP (147.15 g) were added and reacted for 15 hours to obtain a polyamic acid solution (e). The number average molecular weight of this polyamic acid solution (e) was 25,000, and the weight average molecular weight was 65,000. After adding NMP to this polyamic acid solution (e) (450.0 g), the content of the polyamic acid solution (d) was diluted to 10 mass%, followed by acetic anhydride (96.7 g) and pyridine (29.97 g) as the imidization catalyst. ) Was added and reacted at 70°C for 3.5 hours. This reaction solution was poured into methanol (3,600 mL), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide (E). The imidation ratio of this polyimide (E) was 72%.

<Example 1>

NEP (198 g) was added to the polyimide (A) (13.5 g) obtained in Synthesis Example 1 and the polyimide (B) (13.5 g) obtained in Synthesis Example 2, and dissolved by stirring at 70°C for 20 hours. To this solution, NEP (17.91 g), GBL (151.2 g), PB (180 g), DME (144 g), and TM-BIP-A (1.89 g) were added and stirred at 25°C for 2 hours. The solution was filtered through a filter having a pore diameter of 1 µm to prepare the liquid crystal aligning agent [A] of the present invention.

<Example 2>

NMP (150.73 g) was added to the polyimide (A) (13.3 g) obtained in Synthesis Example 1 and the polyimide (B) (13.3 g) obtained in Synthesis Example 2, and dissolved by stirring at 70°C for 20 hours. To this solution, NMP (65.30 g), GBL (115.02 g), BCS (251.6 g), DME (107.8 g) and TM-BIP-A (1.86 g) were added and stirred at 25°C for 2 hours. The solution was filtered through a filter having a pore diameter of 1 µm to prepare the liquid crystal aligning agent [B] of the present invention.

<Example 3>

NMP (150.73 g) was added to the polyimide (C) (13.3 g) obtained in Synthesis Example 3 and the polyimide (E) (13.3 g) obtained in Synthesis Example 5, and dissolved by stirring at 70°C for 20 hours. To this solution, NMP (65.30 g), GBL (115.02 g), BCS (251.6 g), DME (107.8 g) and TM-BIP-A (1.86 g) were added and stirred at 25°C for 2 hours. The solution was filtered through a filter having a pore diameter of 1 µm to prepare a liquid crystal aligning agent [C] of the present invention.

<Example 4>

NEP (198 g) was added to the polyimide (D) (13.5 g) obtained in Synthesis Example 4 and the polyimide (E) (13.5 g) obtained in Synthesis Example 5, and dissolved by stirring at 70°C for 20 hours. To this solution, NEP (17.91 g), GBL (151.2 g), PB (180 g), DME (144 g), and TM-BIP-A (1.86 g) were added and stirred at 25°C for 2 hours. The solution was filtered through a filter having a pore diameter of 1 µm to prepare the liquid crystal aligning agent [D] of the present invention.

<Example 5>

NEP (150.73 g) was added to the polyimide (A) (13.3 g) obtained in Synthesis Example 1 and the polyimide (E) (13.3 g) obtained in Synthesis Example 5, and dissolved by stirring at 70°C for 20 hours. To this solution, NEP (65.30 g), GBL (115.02 g), BCS (251.6 g), DME (107.8 g) and TM-BIP-A (1.86 g) were added and stirred at 25°C for 2 hours. The solution was filtered through a filter having a pore diameter of 1 µm to prepare the liquid crystal aligning agent [E] of the present invention.

<Comparative Example 1>

NEP (198 g) was added to the polyimide (A) (13.5 g) obtained in Synthesis Example 1 and the polyimide (B) (13.5 g) obtained in Synthesis Example 2, and dissolved by stirring at 70°C for 20 hours. To this solution, NEP (169.11 g), PB (216 g), DME (108 g), and TM-BIP-A (1.89 g) were added and stirred at 25°C for 2 hours. The solution was filtered through a filter having a pore diameter of 1 µm to prepare a liquid crystal aligning agent [F].

<Comparative Example 2>

NEP (148.59 g) was added to the polyimide (A) (10.13 g) obtained in Synthesis Example 1 and the polyimide (B) (10.13 g) obtained in Synthesis Example 2, and dissolved by stirring at 70°C for 20 hours. To this solution, NEP (261.67 g), PB (287.95 g) and TM-BIP-A (1.42 g) were added and stirred at 25°C for 2 hours. The solution was filtered through a filter having a pore diameter of 1 µm to prepare a liquid crystal aligning agent [G].

<Comparative Example 3>

NEP (195.07 g) was added to the polyimide (A) (13.3 g) obtained in Synthesis Example 1 and the polyimide (B) (13.3 g) obtained in Synthesis Example 2, and dissolved by stirring at 70°C for 20 hours. To this solution, NEP (202.08 g), PB (212.79 g), DIBK (70.93 g) and TM-BIP-A (1.86 g) were added and stirred at 25°C for 2 hours. The solution was filtered through a filter having a pore diameter of 1 µm to prepare a liquid crystal aligning agent [H].

[Method of forming and evaluating coating film]

The prepared liquid crystal aligning agent was applied to a substrate by an inkjet method, and preliminary drying and main firing were performed to form a coating film. The inkjet coating was evaluated under the following conditions using an inkjet apparatus (model IJ-1021) manufactured by Shibaura Mechatronics.

Inkjet application conditions:

Head: H18, H1A

Nozzle No./Head = 256

Head Nozzle Pitch: 396.88 um

Head Offset: 198.43 um

Scan count: 2 Scan

Drop Pitch (X) in the head array direction: 99.22 um

Stage speed: 512 ㎜/sec, Frequency: 4000 ㎐

Drop Pitch (Y) in the stage movement direction: 128 um

Application pattern setting value: 80 ㎜ × 80 ㎜

Film thickness: 1000 Å.

Substrate: In the evaluation of the Halo area, a glass substrate in which Cr or ITO electrodes were formed on one entire surface at 100×100 mm was used. A TFT substrate was used for evaluation of unevenness around the contact hole (C/H unevenness).

Leaving time from application end to pre-drying: 45 seconds

Pre-drying: The substrate was placed on a pin having a height of 1 mm, placed on a hot plate set at 90°C, and dried for 40 seconds.

Main firing: 230 ℃/20 minutes (IR oven)

<How to evaluate the Halo Area>

The evaluation of the Halo area of the end portion of the liquid crystal alignment film was observed with an optical microscope (manufactured by Nikon, ECLIPSE L300N) of the color tone variation (film thickness nonuniformity) at the top, bottom, left, and right sides of the coating direction with respect to the coating direction. By doing so. Specifically, the magnification was observed with an optical microscope at a magnification of 2.5 times, and the length of the color tone change (film thickness non-uniformity) of the obtained coating film image was measured. All coating film images were obtained at the same magnification. The average value of the color tone change (film thickness non-uniformity) of the top, bottom, left and right ends of the coating film was 7 mm or more, and △, 5 mm and less were △ and less than 5 mm.

<C/H non-uniformity evaluation method>

The in-plane of the coating film obtained above was observed with an optical microscope at a magnification of 5 times, and the number of non-uniformities around C/H was 20% or less of the number of C/Hs in the field of view was set to "○", and more than that was set to "x". .

The following table shows the evaluation results of the liquid crystal aligning agent obtained in Examples 1 to 5 and Comparative Examples 1 to 3.

Industrial availability

The liquid crystal aligning agent of the present invention is useful in industry because it can solve the display irregularity in the vicinity of the frame by increasing the adhesiveness between the sealing agent and the liquid crystal aligning film in a frame narrow liquid crystal display element capable of securing many display surfaces.

Claims (7)

It is a liquid crystal aligning agent containing at least one polymer and an organic solvent selected from a polyimide precursor which is a reactant of a tetracarboxylic acid derivative and a diamine and a polyimide that is an imide thereof, and the organic solvent is
Component A: At least one selected from γ-butyrolactone and γ-valerolactone
B component: contains at least one selected from dipropylene glycol dimethyl ether and diacetone alcohol, the content of the A component and the B component is 25% by weight or less, respectively, and the content difference between the A component and the B component is 5% by weight or less Characterized in that, a liquid crystal aligning agent. According to claim 1,
In addition, as component C, at least one member selected from N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone and N-butyl-2-pyrrolidone is contained, and these C components are liquid crystal alignment The liquid crystal aligning agent characterized by being 40 weight% or less with respect to the weight of the whole agent. The method of claim 1 or 2,
The said liquid crystal aligning agent whose said polymer contains the side chain structure of following formula [1-1].

In formula [1-1], Y ¹ and Y ³ are each independently a single bond, -(CH ₂ ) _a- (a is an integer from 1 to 15), -O-, -CH ₂ O-,- It represents at least 1 sort(s) selected from the group which consists of COO- and -OCO-.
Y ² represents a single bond or -(CH ₂ ) _b- (b is an integer from 1 to 15) (however, when Y ¹ or Y ³ is a single bond, -(CH ₂ ) _a -, Y ² is A single bond, and Y ¹ is at least one member selected from the group consisting of -O-, -CH ₂ O-, -COO- and -OCO-, and/or Y ³ is -O-, -CH ₂ O- , When at least one member selected from the group consisting of -COO- and -OCO-, Y ² is a single bond or -(CH ₂ ) _b -).
Y ⁴ represents at least one divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, or a divalent organic group having 17 to 51 carbon atoms having a steroid skeleton, and any hydrogen on the cyclic group The atom may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom.
Y ⁵ represents at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocyclic ring, and any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms The group may be substituted with a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms or a fluorine atom.
Y ⁶ is at least selected from the group consisting of a C1-C18 alkyl group, a C2-C18 alkenyl group, a C1-C18 fluorine-containing alkyl group, a C1-C18 alkoxy group and a C1-C18 fluorine-containing alkoxy group. 1 type is shown. n represents the integer of 0-4. The method according to any one of claims 1 to 3,
The said liquid crystal aligning agent whose tetracarboxylic dianhydride component contains tetracarboxylic dianhydride represented by following formula [3].

In formula [3], X ₁ is a C4-C13 tetravalent organic group, and also contains a C4-C10 non-aromatic cyclic hydrocarbon group. The method of claim 4,
A liquid crystal aligning agent whose X ₁ is a structure represented by the following formula.

R ₃ to R ₆ , R ₂₄ and R ₂₅ each independently contain a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or a fluorine atom It is a C1-C6 monovalent organic group or a phenyl group. The liquid crystal aligning film obtained from the liquid crystal aligning agent in any one of Claims 1-5. The liquid crystal display element provided with the liquid crystal aligning film of Claim 6.