KR20200130427A - Liquid crystal aligning agent, polymer for obtaining it, liquid crystal aligning film, and liquid crystal display element using same - Google Patents

Abstract

식 중, X는 디이소시아네이트 유도체에서 유래하는 2가의 유기기를 나타내고, Y는 디아민 유도체에서 유래하는 2가의 유기기를 나타낸다. R₁은 탄소수 1∼4의 알킬기를 나타내고, 분기하고 있어도 된다. R₂는 수소 원자, 탄소수 1∼4의 지방족 탄화수소기, 또는 하기 식 (1-1)로 표시되는 유기기를 나타낸다. Ra 및 Rb는 각각 독립하여, 수소 원자, 또는 탄소수 1∼2의 지방족 탄화수소기를 나타낸다.
[화학식 2]

식 중, 흑점은 질소 원자에의 결합 개소를 의미하고, R₁, Ra 및 Rb는 상기의 R₁, Ra 및 Rb와 동의이다. The present invention provides a liquid crystal aligning agent containing a polymer which is a polyurea and a polyurea copolymer having a structure represented by the following formula (1).
[Formula 1]

In the formula, X represents a divalent organic group derived from a diisocyanate derivative, and Y represents a divalent organic group derived from a diamine derivative. R ₁ represents an alkyl group having 1 to 4 carbon atoms, and may be branched. R ₂ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, or an organic group represented by the following formula (1-1). Each of Ra and Rb independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 2 carbon atoms.
[Formula 2]

In the above formula, is a black dot means a binding point of the nitrogen atom, R _1, Ra and Rb are of the R _1, Ra and Rb and consent.

Description

Liquid crystal aligning agent, polymer for obtaining it, liquid crystal aligning film, and liquid crystal display element using same

The present invention relates to a liquid crystal aligning agent, a polymer for obtaining the same, a liquid crystal aligning film, and a liquid crystal display device using the same.

In a liquid crystal display element, a liquid crystal aligning film plays a role of aligning a liquid crystal in a certain direction. Currently, the main liquid crystal aligning film used industrially is formed by applying a polyimide liquid crystal aligning agent made of a polyamic acid (also called a polyimide precursor or polyamic acid) or a polyimide solution to a substrate and firing. . In addition, when the liquid crystal is aligned in parallel or obliquely aligned with respect to the substrate surface, after forming a film, a surface stretching treatment (rubbing treatment) by rubbing is performed. As a method of replacing the rubbing treatment, a method using an anisotropic photochemical reaction by irradiation of polarized ultraviolet rays or the like is also proposed.

In order to improve the display characteristics of a liquid crystal display device, numerous technologies have been proposed. For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2-287324), it is proposed to use a polyimide resin having a specific repeating structure in order to obtain a high voltage retention rate (VHR). In addition, in Patent Document 2 (Japanese Unexamined Patent Publication No. Hei 10-104633), in order to shorten the time until the afterimage is erased, it is proposed to use a soluble polyimide having a nitrogen atom other than an imide group.

Japanese Unexamined Patent Application Publication No. Hei 2-287324 Japanese Unexamined Patent Publication No. Hei 10-104633

In recent years, along with the multifunctional and diversified liquid crystal displays (LCD panels), development is progressing from displays using glass substrates to flexible displays using resin substrates (plastic substrates, that is, film substrates). Accordingly, a liquid crystal alignment film obtainable by firing at a low temperature is required, and in addition, reliability (high voltage retention, etc.) required for the liquid crystal alignment film is also required.

Examples of the material used for the liquid crystal aligning film include polyimide precursors such as polyamic acid or polyamic acid ester, and polyimide obtained by dehydrating them by firing or by chemical reaction. Among these, polyamic acid is easy to synthesize and has excellent solubility in a solvent, so that a liquid crystal aligning agent excellent in coating properties and film forming properties on a substrate can be obtained. However, since polyamic acid is easily decomposed by hydrolysis or the like due to its structure, it is difficult to ensure reliability over a long period of time in a liquid crystal alignment film obtained using this.

On the other hand, the soluble polyimide (polyimide soluble in the solvent obtained by the dehydration reaction of polyamic acid) is preimidized, and therefore does not require a heat curing step of imidization by heating. Firing becomes possible. Moreover, since it is excellent in chemical stability and heat resistance, in a liquid crystal aligning film obtained using a soluble polyimide, it becomes easy to ensure reliability over a long period of time. However, soluble polyimide has few choices of solvents that can be dissolved, and therefore, the solvents that can be used are limited. As a result, when soluble polyimide is used, precipitation or the like occurs during coating and during film formation, and the coating film (塗膜) is prone to defects. In recent years, with the increase in size, high definition, and diversification of the use environment of LCD panels, there is a demand for a method capable of solving each problem and improving various characteristics.

The present invention has been made in view of the above circumstances, and its subject is to provide a liquid crystal aligning agent that can be baked at a low temperature and has excellent printability (the solubility of the obtained polymer in an organic solvent). Moreover, it exists in providing the polymer which can obtain the said liquid crystal aligning agent. Moreover, in the case of performing a rubbing treatment, it is to provide a liquid crystal alignment film having excellent rubbing resistance, good liquid crystal alignment (that is, a low pre-tilt angle can be realized), and a high voltage retention. Further, it is to provide a liquid crystal display device having the liquid crystal alignment film.

As a result of intensive research, the inventors of the present invention have found that a polymer having a specific structure and a liquid crystal aligning agent using the same are effective to achieve the above object, and have come to complete the present invention. In addition, the polymer is novel, and the monomer for obtaining the polymer also contains a novel compound.

That is, this invention makes the following 1.-9. the summary.

1. A liquid crystal aligning agent containing a polymer which is a polyurea and a polyurea copolymer having a structure represented by the following formula (1):

[Formula 1]

In the formula, X represents a divalent organic group derived from a diisocyanate derivative, and Y represents a divalent organic group derived from a diamine derivative. R ₁ represents an alkyl group having 1 to 4 carbon atoms, and may be branched. R ₂ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, or an organic group represented by the following formula (1-1). Each of Ra and Rb independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 2 carbon atoms.

[Formula 2]

In the above formula, it is a black dot means a binding point of the nitrogen atom, and R _1, Ra and Rb are of the R _1, Ra and Rb and agreement (同意).

２. The liquid crystal aligning agent according to 1., containing a diamine derivative represented by the following formula (2) and a polymer obtained from a diisocyanate derivative, which is a polyurea and a polyurea copolymer:

[Formula 3]

In the formula, A represents an aliphatic hydrocarbon group or a divalent organic group of an aromatic hydrocarbon group, and B and C each independently represent a single bond or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. R ₁ , R ₂ , Ra and Rb are the same as R ₁ , R ₂ , Ra and Rb above.

3. The liquid crystal aligning agent according to 2., which contains a diamino compound represented by the following formula (3) among the diamine derivatives and a polyurea and polyurea copolymer polymer obtained from a diisocyanate derivative:

[Formula 4]

In the formula, Ar represents an aryl group, and D represents a single bond or a hydrocarbon group having 1 to 5 carbon atoms. R ₁ , R ₂ , Ra and Rb are the same as R ₁ , R ₂ , Ra and Rb above.

4. The liquid crystal aligning agent according to 3., containing a diamino compound represented by the following formula (3-a) among the diamine derivatives and a polyurea and a polyurea copolymer polymer obtained from a diisocyanate derivative:

[Formula 5]

Wherein, D and R ₁ is D and R ₁ and consent of the.

5. A polymer obtained from a diamino compound represented by the following formula (3-1) and a diisocyanate derivative:

[Formula 6]

In the formula, R ₁ represents an alkyl group having 1 to 4 carbon atoms, and may be branched. B represents a single bond or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. Each of Ra and Rb independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 2 carbon atoms.

6. The polymer according to 5. obtained from the diamino compound and at least one of the diisocyanate derivatives represented by the following formulas (4-1) to (4-11) and (4-13):

[Formula 7]

7. A liquid crystal aligning agent using the polymer described in 5. or 6.

8. １.∼4. And the liquid crystal aligning film obtained from the liquid crystal aligning agent in any one of 7.

９. A liquid crystal display element using the liquid crystal aligning film described in 8.

ADVANTAGE OF THE INVENTION According to this invention, baking at low temperature is possible, and in addition to being able to obtain a high-quality liquid crystal aligning film, a liquid crystal aligning agent excellent in printability can be provided. Moreover, according to this invention, a novel polymer for obtaining the said liquid crystal aligning agent can be provided. Further, according to the present invention, in the case of performing the rubbing treatment, in addition to being excellent in rubbing resistance and realizing a low pre-tilt angle, a liquid crystal alignment film having a high voltage retention can be provided. Further, according to the present invention, a liquid crystal display device using the liquid crystal alignment film can be provided.

The liquid crystal aligning agent as an aspect of the present invention is obtained from a diamine derivative represented by the formula (2) (hereinafter sometimes referred to as ``diamine'') and a diisocyanate derivative (hereinafter referred to as ``diisocyanate''). , Contains a polymer that is an aspect of the present invention.

<Diamine used in the present invention>

The diamine used for this invention is represented by Formula (2).

[Formula 8]

In the formula, A represents a divalent organic group of an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and B and C each independently represent a single bond or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. R ₁ represents an alkyl group having 1 to 4 carbon atoms, and may be branched. R ₂ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, or an organic group represented by formula (1-1). Each of Ra and Rb independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 2 carbon atoms.

From the viewpoint of obtaining a liquid crystal alignment film excellent in polymerization reactivity of the monomer, heat resistance or liquid crystal alignment, in formula (2), A is an aromatic hydrocarbon group, B is an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and C is a single bond. If it is, it is preferable. Formula (2) specifically includes the following structures.

[Formula 9]

　

　

In the formula, Ar represents an aryl group, and D represents a single bond or a hydrocarbon group having 1 to 5 carbon atoms. R ₁ , R ₂ , Ra and Rb are the same as R ₁ , R ₂ , Ra and Rb above.

In the case of taking into consideration the viewpoints such as ease of obtaining a reagent for synthesizing diamine, good reactivity with diisocyanate, and good physical properties of the polymer obtained, in formula (3), Ar is preferably a phenyl group. And R ₂ is preferably a hydrogen atom. Therefore, the formula (3) is preferably a structure represented by the following formula (3-a)'. Among them, in formula (3), it is preferable that each of Ra and Rb is a hydrogen atom. Therefore, Formula (3) is particularly preferably represented by Formula (3-a).

[Formula 10]

Wherein, D and R ₁ is D and R ₁ and consent of the.

From the viewpoint of obtaining the target monomer suitably, and the point that all of the above properties are easily improved, the above formula (3-a)' is preferably represented by the following formula (3-1). do.

[Formula 11]

In the formula, B, R ₁ , Ra and Rb are the same as those of B, R ₁ , Ra and Rb described above. In formula (3-1), when B is 1 and 2 carbon atoms, and Ra and Rb are each hydrogen atom, formula (3-1) is represented by formulas (3-1a) and (3-1b).

[Formula 12]

In the formula, R ₁ has the same meaning as R ₁ above.

However, the specific example of the diamine represented by Formula (2) is not limited to the diamine represented by Formula (3). If the effect of the present invention (for example, a low pre-tilt angle can be achieved) is not impaired, in synthesizing the polymer, a part of the diamine represented by the formula (2) or (3) is , You may substitute with a diamine represented by Formula (5) mentioned later.

<Diisocyanate used in the present invention>

The diisocyanate used for this invention is represented by Formula (4).

[Formula 13]

In the formula, X represents a divalent organic group. Formula (4) is preferably represented by formulas (4-1) to (4-11) and (4-13).

[Formula 14]

In the case of using an aliphatic diisocyanate represented by formulas (4-1) to (4-5), compared to the case of using an aromatic diisocyanate represented by formulas (4-6) to (4-13) The polymer is well soluble in the solvent. On the other hand, the aromatic diisocyanate reacts favorably with a diamine as compared to the aliphatic diisocyanate. For example, aromatic diisocyanate as shown in Formula (4-6) and Formula (4-7) reacts favorably with diamine, and can improve the heat resistance of the obtained liquid crystal aligning film.

From the viewpoint of being a compound having high versatility for obtaining the polymer, and from the viewpoint of improving the properties of the obtained polymer, formula (4) is represented by formula (4-1), formula (4-7), and formula (4). -8), Formula (4-9) or Formula (4-10) is preferable. Moreover, as for Formula (4), Formula (4-13) is preferable from a viewpoint that the liquid crystal aligning property of the obtained liquid crystal aligning film becomes favorable.

However, formula (4) is not limited to the above as long as it is within the scope of the spirit of the present invention. Depending on target properties such as a polymer obtained, a liquid crystal aligning agent, and a liquid crystal aligning film, an easily available diisocyanate can be suitably used. You may use diisocyanate in combination of 2 or more types.

<Diamine>

In obtaining the polymer, a part of the diamine represented by formula (2) may be substituted with other diamines (other diamines). In general, diamines are rich in types, and there are many compounds having organic groups having various functions, so by using other diamines together, an additional effect can be given to the polymer, or the above effect of the diamine is further improved. There are cases where you can or do. The ratio of the number of moles of other diamines to the number of moles of diamine represented by Formula (2) is arbitrary within a range in which the effects of the present invention (for example, those capable of achieving a low pre-tilt angle) are not impaired. For example, the ratio can be 0.5 or less. Of course, it is not necessary to use other diamines together. As such other diamine, a diamine represented by following formula (5) is mentioned, for example.

[Formula 15]

In the formula, Y represents a divalent organic group. Examples of the structure of Y are listed as the following formulas (Y-1) to (Y-49) and formulas (Y-57) to (Y-175), but are not limited thereto. Each R ₅ independently represents a hydrogen atom, a methyl group, or an ethyl group. Polyamic acid is given in the reaction of tetracarboxylic dianhydride and diamine, and polyurea is given in the reaction of diisocyanate and diamine.

[Formula 16]

[Formula 17]

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

[Formula 23]

In the formula, n is an integer of 1 to 6 unless otherwise specified.

<polymer>

A polymer that is a polyurea and a polyurea copolymer means a polymer that is a polyurea and/or a polyurea copolymer. Such a polymer is represented by formula (1).

[Formula 24]

In the formula, X represents a divalent organic group derived from diisocyanate, and Y represents a divalent organic group derived from diamine. R ₁ represents an alkyl group having 1 to 4 carbon atoms, and may be branched. R ₂ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, or an organic group represented by the following formula (1-1). Each of Ra and Rb independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 2 carbon atoms.

[Formula 25]

In the above formula, is a black dot means a binding point of the nitrogen atom, R _1, Ra and Rb are of the R _1, Ra and Rb and consent.

Since polyurea forms strong hydrogen bonds due to the polarity of the urea bonding site, the resulting membrane has excellent mechanical strength. On the other hand, the strong hydrogen bonding force becomes a factor of aggregation of the polymer, which may deteriorate the stability of the polymer solution, etc. (the viscosity of the polymer solution increases, a part of the polymer precipitates, the polymer solution gels, etc.). Therefore, depending on the structure of the polyurea, the usable solvent is limited, and for example, it is necessary to use a solvent having a high polarity and a high boiling point.

The polymer has a structure represented by formula (1), that is, a structure in which an organic group represented by formula (1-1) is substituted on the N atom of polyurea. The organic group represented by formula (1-1) inhibits the formation of hydrogen bonds, thereby preventing aggregation of polymers. For this reason, the stability of the polymer solution is greatly improved. Therefore, in obtaining a polymer solution of polyurea, it is possible to widen the choice of solvents that can be used, and furthermore, firing at low temperatures and large improvement in printability are also possible. In addition, the urea bond site may form a hydantoin ring or a crosslinking between molecules, depending on the firing temperature during film formation.

<Reaction solution>

The reaction solution (organic solvent used in the reaction for obtaining the polymer) is not particularly limited as long as it is a solution in which the polymer is dissolved. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide Seed, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoa Mil ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoiso Propyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene Glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl Ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate , Butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, lactic acid Methyl, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate , 3-methoxy ethyl propionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl, 3-methoxy butyl propionate, diglyme, 4-hydroxy-4-methyl-2-pentanone , 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropane And amides. These may be used alone or in combination of two or more. As long as the polymer does not precipitate, even a solution that does not dissolve the polymer can be mixed with the reaction solution and used.

In addition, since moisture in the reaction solution inhibits the polymerization reaction and furthermore causes hydrolysis of the resulting polymer, it is preferable to use a dehydration-dried reaction solution. When diisocyanate and diamine are reacted in a reaction solution, the reaction solution in which the diamine is dispersed or dissolved is stirred, and the diisocyanate is added as it is, or dispersed or dissolved in the reaction solution. Conversely, a reaction in which diisocyanate is dispersed or dissolved. A method of adding a diamine to a solution, a method of alternately adding a diisocyanate and a diamine to a reaction solution, etc. are mentioned, and any of these methods may be used.

In addition, when the diisocyanate or diamine is made of a plurality of compounds, it may be reacted in a state of being mixed in advance, or may be individually sequentially reacted, or a low molecular weight body reacted individually may be mixed and reacted to obtain a high molecular weight body. The polymerization temperature in that case can be selected from -20°C to 150°C, but is preferably in the range of -5°C to 100°C. In addition, the reaction can be carried out at an arbitrary concentration, but if the concentration is too low, it becomes difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring becomes difficult. Therefore, diisocyanate and diamine The total concentration in the reaction solution of is preferably 1% by mass to 50% by mass, more preferably 5% by mass to 30% by mass. The initial reaction is carried out at a high concentration, and a reaction solution can be added thereafter.

In the polymerization reaction of polyurea, the ratio of the total number of moles of diisocyanate to the total number of moles of diamine is preferably 0.8 to 1.2. Similar to the normal polycondensation reaction, the closer this molar ratio is to 1.0, the greater the molecular weight of the resulting polymer.

[Recovery of polymer]

In order to recover the produced polymer from the reaction solution, the reaction solution may be added to a poor solvent to precipitate the polymer. Examples of poor solvents include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water. The polymer injected into a poor solvent and precipitated may be collected by filtration and then dried at room temperature or heated under normal pressure or reduced pressure. Further, by re-dissolving the recovered polymer in an organic solvent, and repeating the reprecipitation and re-recovery operations 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons, and the like. When three or more poor solvents selected from these are used, the efficiency of purification is further increased, and thus it is preferable.

The molecular weight of the polymer is a weight average molecular weight measured by GPC (Gel Permeation Chromatography) method when considering the strength of the coating film obtained from the polymer, ease of operation when forming the coating film, and uniformity of the film thickness of the coating film. It is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000.

<Liquid crystal aligning agent>

The liquid crystal aligning agent which is an aspect of this invention is a coating liquid for forming a liquid crystal aligning film, and a resin component for forming a coating film (resin film) is dissolved in an organic solvent. The resin component contains at least one polymer. In the liquid crystal aligning agent, the content of the resin component is preferably 2% by mass to 20% by mass, more preferably 3% by mass to 15% by mass, and particularly preferably 3% by mass to 10% by mass. In the present invention, all of the polymers contained in the resin component may be the aforementioned polymers, and other polymers (other polymers) may be contained as long as they are within the scope of the present invention. In the resin component, the content of the other polymer is 0.5% by mass to 15% by mass, preferably 1% by mass to 10% by mass. Examples of such other polymers include acrylic polymers, methacrylic polymers, novolac resins, polyhydroxystyrene, polyimide precursors, polyimides, polyamides, polyesters, celluloses, polysiloxanes, and the like.

The organic solvent used for the said liquid crystal aligning agent is not specifically limited if it is an organic solvent which dissolves a resin component. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone , N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy- N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, Methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, 4-hydroxy-4-methyl-2-pentanone, and the like. These may be used alone or in combination of two or more.

The liquid crystal aligning agent may contain components other than the above. Examples thereof include a solvent or compound that improves the uniformity of the film thickness or smoothness of the surface of a coating film formed by applying a liquid crystal aligning agent, or a compound that improves adhesion between the liquid crystal aligning film and the substrate.

As a solvent (poor solvent) that improves the uniformity of the film thickness and smoothness of the surface, a solvent having a low surface tension, for example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, Butyl Cellosolve, Methyl Cellosolve Acetate, Ethyl Cellosolve Acetate, Butyl Carbitol, Ethyl Carbitol, Ethyl Carbitol Acetate, Ethylene Glycol, Ethylene Glycol Monoacetate, Ethylene Glycol Monoisopropyl Ether, Ethylene Glycol Monobutyl Ether , Propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol mono Acetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3- Methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone , Methylcyclohexene, propyl ether, dihexyl ether, 1-hexanol, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, Propylene glycol acetate monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid , 3-methoxypropionate propyl, 3-methoxypropionate butyl, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy- 2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2- Ethoxypropoxy)propanol, lactic acid methyl ester, lactic acid ethyl ester, lactic acid n-propyl ester, lactic acid n-part Tyl ester, isoamyl lactate, etc. are mentioned. These poor solvents may be used alone or in combination of multiple types. When using the said poor solvent, it is preferable that it is 5 mass%-80 mass% of the whole organic solvent contained in a liquid crystal aligning agent, More preferably, it is 20 mass%-60 mass %.

Examples of the compound for improving the uniformity of the film thickness and the smoothness of the surface of the coating film include a fluorine-based surfactant, a silicone-based surfactant, and a nonionic surfactant. More specifically, for example, Ftop EF301, EF303, EF352 (manufactured by Dochem Products), Megapac F171, F173, R-30 (manufactured by Dinippon Ink), Florade FC430, FC431 (manufactured by Sumitomo 3M) ), Asahigard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Corporation), and the like. The ratio of use of these surfactants is preferably 0.01 parts by mass to 2 parts by mass, and more preferably 0.01 parts by mass to 1 part by mass per 100 parts by mass of the resin component contained in the liquid crystal aligning agent.

As a specific example of the compound which improves the adhesiveness of a liquid crystal aligning film and a board|substrate, the functional silane-containing compound, an epoxy group-containing compound etc. shown below are mentioned. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3 -Aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxy Carbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetri Amine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl Acetate, 9-triethoxysilyl-3,6-diazanonylacetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3- Aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltri Ethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol di Glycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetragly Cidyl-2,4-hexanediol, N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, etc. are mentioned.

Further, in addition to improving the adhesion between the substrate and the film, the following phenoplast additives may be added for the purpose of preventing deterioration of electrical properties caused by irradiation of light by the backlight. Although specific phenoplast additives are shown below, it is not limited to this structure.

[Formula 26]

In the case of using a compound that improves adhesion between the substrate and the film, the amount of the compound is preferably 0.1 to 30 parts by mass based on 100 parts by mass of the resin component contained in the liquid crystal aligning agent, and more preferably It is 1 mass part to 20 mass parts. If the amount is less than the above value, it becomes difficult to improve the adhesiveness, and if it is more than the above value, the liquid crystal orientation may deteriorate.

In the liquid crystal aligning agent, in addition to the solvents and compounds described above, as long as the effect of the present invention is not impaired, for the purpose of changing electrical properties such as dielectric constant or conductivity of the liquid crystal aligning film, dielectrics or conductive materials, furthermore A predetermined crosslinkable compound may be added for the purpose of increasing the hardness and density of the film when the liquid crystal aligning film is formed.

<Liquid crystal alignment film/liquid crystal display element>

After applying the said liquid crystal aligning agent on a board|substrate and firing, it aligns by rubbing, light irradiation, etc., and can obtain the liquid crystal aligning film which is one aspect of this invention. As the substrate, a highly transparent glass substrate or a plastic substrate (for example, an acrylic substrate or a polycarbonate substrate) can be used. Further, it is preferable to use a substrate on which an ITO electrode or the like for driving a liquid crystal is formed from the viewpoint of simplifying the process of manufacturing a liquid crystal display element. In addition, in a reflective liquid crystal display device, an opaque material such as a silicon wafer may be used for the substrate on one side, and a material that reflects light such as aluminum may be used as the electrode in this case. The method of applying the liquid crystal aligning agent is not particularly limited, but industrially, spin coat printing, screen printing, offset printing, flexo printing, inkjet printing, and the like are common. Other coating methods include dip, roll coater, slit coater, spinner, and the like, and these methods may be used depending on the purpose.

The firing can be carried out at 50°C to 300°C, preferably 80°C to 250°C by a heating means such as a hot plate. A coating film can be formed by evaporating the organic solvent in a liquid crystal aligning agent. When the thickness of the coating film is too thick, the power consumption of the liquid crystal display device tends to increase, and when it is too thin, the reliability of the liquid crystal display device may decrease. Therefore, it is preferably 5 nm to 300 nm, more preferably 10 nm to 150 nm. In the case of horizontal alignment or oblique alignment of the liquid crystal, the coated film after firing is subjected to alignment treatment by rubbing or polarized ultraviolet irradiation.

After obtaining the substrate with a liquid crystal aligning film from the said liquid crystal aligning agent by the said method, the liquid crystal display element which is one aspect of this invention can be obtained by producing a liquid crystal cell by a known method. As an example of a method of producing a liquid crystal cell, a pair of substrates on which a liquid crystal alignment film is formed is prepared, spacers are scattered on the liquid crystal alignment film of one substrate, and the surface of the liquid crystal alignment film is inside. A method of bonding the substrates of, and injecting a liquid crystal under reduced pressure to seal it is mentioned. Alternatively, after dropping the liquid crystal onto the surface of the liquid crystal aligning film on which the spacers are scattered, a method of bonding the substrates and sealing them is mentioned. The thickness of the spacer at this time is preferably 1 μm to 30 μm, more preferably 2 μm to 10 μm. Since the liquid crystal display element produced using the liquid crystal aligning agent is excellent in reliability, it can be suitably used for a large-screen, high-definition liquid crystal TV or the like.

Example

<Synthesis of diamine>

Example 1

Synthesis of ethyl (4-aminobenzyl) glycinate [NG4ABA]

[Formula 27]

1st process

To a 1 L 4-neck flask equipped with a nitrogen introduction tube and a reflux tube, 105.6 g (0.694 mol) of glycine ethyl hydrochloride, 500 g of THF, and 93.6 g (0.925 mol) of triethylamine were added, and at room temperature using a mechanical stirrer. After stirring for 1 hour, it was heated at a temperature at which THF was refluxed (set 70°C), and 50.0 g (0.231 mol) of 4-nitrobenzyl bromide was dissolved in 500.0 g of THF, and this was slowly added dropwise. After completion of the dropping, an additional 24 It was allowed to react for time. When 4-nitrobenzyl bromide disappeared, the reaction was terminated, and the precipitated solid was removed by filtration, and THF was removed by a rotary evaporator, and the resulting crude was re-dissolved with 300.0 g of ethyl acetate. Made it. This solution was washed 3 times with 100 g of pure water, 300 g of 10% hydrochloric acid aqueous solution was added, stirred for 1 hour, and the water layer side was recovered, and the aqueous layer was washed 3 times with 100 g of ethyl acetate. . 300 g of ethyl acetate was further added to the aqueous layer, potassium carbonate was slowly added, and the mixture was stirred for 1 hour at a pH of about 10, and the organic phase side was recovered and washed three times with 100 g of pure water. Anhydrous magnesium sulfate was added to the organic phase, dried, filtered, and activated carbon was added and stirred for a while, then the activated carbon was removed by filtration, and the solvent was removed with a rotary evaporator, and the target substance (nitro body) was pale yellow. 46.0 g (0.193 mol) of viscous bodies were obtained. It was confirmed by ¹ H-NMR that the target product was obtained.

¹ H NMR (500 MHz, CDCl ₃ ): δ 8.2 (2H), 7.53 (2H), 4.22 (2H), 3.93 (2H), 3.42 (2H), 1.89 (1H), 1.27 (3H)

2nd process

To a 500 ml four-necked flask equipped with a nitrogen introduction tube and a stirrer, 45.0 g (0.19 mol) of the nitro substance obtained above, 300.0 g of THF, and 4.5 g of iron-doped platinum carbon were added, and the inside of the container was carefully placed under a hydrogen atmosphere. It was substituted and reacted at room temperature for 24 hours. When the raw material disappeared, the reaction was terminated, platinum carbon was removed by a membrane filter, activated carbon (manufactured by Shirasagi) was added to the filtrate, and the mixture was stirred at 40°C for 30 minutes. After that, it filtered again, and after removing a solvent with a rotary evaporator, it dried with a high vacuum pump, and 35.4 g (0.17 mol: yield 89%) of the target object pale yellow viscous body was obtained. It was confirmed by ¹ H-NMR that the target product (NG4ABA) was obtained.

¹ H NMR (500MHz, CDCl ₃ ): δ 6.99 (2H), 6.63 (2H), 4.15 (2H), 3.70 (2H), 3.38 (2H), 3.00 (2H), 1.24 (3H)

Example 2

Synthesis of ethyl (3-aminobenzyl) glycinate [NG3ABA]

[Formula 28]

From Example 1, 4-nitrobenzyl bromide as a raw material was changed to 3-nitrobenzyl bromide and synthesized. The target substance (NG3ABA) was obtained as a pale yellow solid, and the yield was 37.4 g (0.18 mol: 94%). The desired product is obtained and confirmed by ¹ H-NMR.

¹ H NMR (500MHz, CDCl ₃ ): δ 7.10 (1H), 6.65 (1H), 6.57 (1H), 4.16 (2H), 3.70 (2H), 3.39 (2H), 3.09 (2H), 1.25 (3H)

Example 3

Synthesis of ethyl (4-aminophenethyl) glycinate [NG4APhA]

[Chemical Formula 29]

1st process

To a 1 L four-necked flask equipped with a nitrogen introduction tube and a reflux tube, 50 g (0.246 mol) of 4-nitrophenethylamine hydrochloride, 500 g of THF, and 62.1 g (0.604 mol) of triethylamine were added, and a mechanical stirrer was used. Then, the mixture was stirred at room temperature for 1 hour, heated at a temperature at which THF was refluxed (set 70°C), and 25.1 g (0.205 mol) of ethyl 2-chloroacetate was dissolved in 300 g of THF, and this was slowly added dropwise. After the dropping was completed, further It was reacted for 24 hours. The reaction was terminated when ethyl 2-chloroacetate disappeared (confirmed by HPLC), the precipitated solid was removed by filtration, THF was removed by a rotary evaporator, and the resulting crude was redissolved with 500 g of ethyl acetate. Made it. This solution was washed three times with 100 g of pure water, 500 g of a 10% hydrochloric acid aqueous solution was added, stirred for 1 hour, the water layer side was recovered, and the aqueous layer was washed three times with 100 g of ethyl acetate. 500 g of ethyl acetate was further added to the aqueous layer, potassium carbonate was slowly added, and the mixture was stirred for 1 hour at a pH of about 10, and the organic phase was recovered and washed three times with 100 g of pure water. Anhydrous magnesium sulfate was added to the organic phase, dried, filtered, and activated carbon was added and stirred for a while, then the activated carbon was removed by filtration, and the solvent was removed with a rotary evaporator, and 34.2 g of a pale yellow viscous body ( 0.136 mol: yield 66%) was obtained. It was confirmed by ¹ H-NMR that the target substance (nitro substance) was obtained.

¹ H NMR (500MHz, CDCl ₃ ): δ 8.14 (2H), 7.37 (2H), 4.16 (2H), 3.43 (2H), 2.95 (4H), 2.19 (1H), 1.25 (3H)

2nd process

To a 500 ml four-necked flask equipped with a nitrogen introduction tube and a stirrer, 30.0 g of the nitro substance obtained above, 300 g of THF, and 3.0 g of iron-doped platinum carbon were added, and the inside of the container was carefully replaced under a hydrogen atmosphere, and at room temperature. It was reacted for 24 hours. When the raw material disappeared, the reaction was terminated, platinum carbon was removed by a membrane filter, activated carbon (manufactured by Shira Corporation) was added to the filtrate, and the mixture was stirred at 40°C for 30 minutes. Then, it filtered again, and after removing a solvent with a rotary evaporator, it dried with a high vacuum pump, and 25.1 g (0.113 mol: yield 95%) of a pale yellow viscous body which is a target product (NG4APhA) was obtained. It was confirmed by ¹ H-NMR that the target product was obtained.

¹ H NMR (500 MHz, CDCl ₃ ): δ 6.99 (2H), 6.60 (2H), 4.18 (2H), 3.42 (2H), 2.89 (2H), 2.86 (2H), 2.75 (2H), 1.24 (3H)

<Abbreviation(略語)>

The abbreviations used in preparation of a liquid crystal aligning agent are as follows.

(Diisocyanate)

IDI: isophorone diisocyanate

4IBI: (isocyanatomethyl)phenyl-isocyanate

DI-3MG: 1,3-bis(4-isocyanatophenoxy)propane

DI-2MG: 1,2-bis(4-isocyanatophenoxy)ethane

[Formula 30]

(Diamine)

NG4ABA: ethyl (4-aminobenzyl) glycinate

NG3ABA: ethyl (3-aminobenzyl) glycinate

NG4APhA: ethyl (4-aminophenethyl) glycinate

Me3ABA: N-methyl-3-aminobenzylamine

Me4APhA: N-methyl-4-aminophenethylamine

DA-3MG: 1,3-di(4-aminophenoxy)propane

[Formula 31]

(menstruum)

NMP: N-methyl-2-pyrrolidone

BCS: Butyl Cellosolve

GBL: γ-butyrolactone

Moreover, the molecular weight measurement conditions of a polyimide are as follows.

Apparatus: Room temperature gel permeation chromatography (GPC) apparatus (SSC-7200) manufactured by Senshu Chemical Co., Ltd.

Column: Shodex's column (KD-803, KD-805)

Column temperature: 50°C

Eluent: N,N'-dimethylformamide (as an additive, lithium bromide-hydrate (LiBr H ₂ O) is 30 mmol/L, phosphoric acid and anhydrous crystals (o-phosphoric acid) are 30 mmol/L, THF is 10ml/L)

Flow rate: 1.0 ml/min

Standard samples for calibration curve preparation: TSK standard polyethylene oxide (molecular weight: about 9000,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weight: about 12,000, 4,000, 1,000) manufactured by Polymer Laboratories

<Synthesis of polymer>

Example 4

DI-2MG/NG3ABA

In a 50 ml two-necked flask equipped with a nitrogen introduction tube and a stirrer, 1.00 g (4.80 mmol) of NG3ABA was measured and dissolved, 13.43 g of NMP was added to dissolve it, and 1.37 g (4.60 mmol) of DI-2MG was added, and a nitrogen atmosphere. It was reacted at 40°C for 24 hours. Thereby, a polymer (polymer solution: P-1) having a concentration of 15% by mass and a viscosity of 420 mPas was obtained. The weight average molecular weight of the obtained polymer was Mw: 46200.

Example 5

DI-2MG/NG4ABA

In a 50 ml two-necked flask equipped with a nitrogen introduction tube and a stirrer, 1.00 g (4.80 mmol) of NG4ABA was weighed, and 13.32 g of NMP was added to dissolve it, and 1.35 g (4.56 mmol) of DI-2MG was added, and a nitrogen atmosphere It was reacted at 40°C for 24 hours. Thereby, a polymer (polymer solution: P-2) having a concentration of 15% by mass and a viscosity of 370 mPas was obtained. The weight average molecular weight of the obtained polymer was Mw: 39800.

Example 6

DI-3MG/NG4APhA

In a 50 ml two-necked flask equipped with a nitrogen introduction tube and a stirrer, 1.00 g (4.50 mmol) of NG4APhA was weighed, 13.20 g of NMP was added to dissolve it, and 1.33 g (4.28 mmol) of DI-3MG was added, and a nitrogen atmosphere. It was reacted at 40°C for 24 hours. Thereby, a polymer (polymer solution: P-3) having a concentration of 15% by mass and a viscosity of 440 mPas was obtained. The weight average molecular weight of the obtained polymer was Mw: 46300.

Example 7

4IBI/NG4APhA, DA-3MG

In a 50 ml two-necked flask equipped with a nitrogen introduction tube and a stirrer, 0.50 g (2.25 mmol) of NG4APhA and 0.58 g (2.25 mmol) of DA-3MG were weighed, and 10.48 g of NMP were added to dissolve it, and 0.77 g (4.41 of 4IBI) was dissolved. mmol) was added and reacted at 40°C for 24 hours in a nitrogen atmosphere. Thereby, a polymer (polymer solution: P-4) having a concentration of 15% by mass and a viscosity of 280 mPas was obtained. The weight average molecular weight of the obtained polymer was Mw: 37300.

Example 8

IDI, DI-3MG/NG4ABA, DA-3MG

In a 50 ml two-necked flask equipped with a nitrogen introduction tube and a stirrer, 0.50 g (2.40 mmol) of NG4ABA and 0.62 g (2.40 mmol) of DA-3MG were weighed, and 13.60 g of NMP was added to dissolve it, and 0.74 g of DI-3MG (2.40 mmol) and IDI 0.54 g (2.42 mmol) were added, and reacted at 40°C for 24 hours in a nitrogen atmosphere. Thereby, a polymer (polymer solution: P-5) having a concentration of 15% by mass and a viscosity of 330 mPas was obtained. The weight average molecular weight of the obtained polymer was Mw: 41600.

Comparative Example 1

DI-2MG/Me3ABA

In a 50 ml two-necked flask equipped with a nitrogen introduction tube and a stirrer, 1.00 g (7.34 mmol) of Me3ABA was weighed, and 19.36 g of NMP was added to dissolve it, and 2.24 g (7.57 mmol) of DI-2MG was added, followed by nitrogen atmosphere. It was reacted at 40°C for 24 hours. Thereby, a polymer (polymer solution: PRef-1) having a concentration of 15% by mass and a viscosity of 530 mPas was obtained. The weight average molecular weight of the obtained polymer was Mw: 39900.

Comparative Example 2

DI-2MG/Me4APhA

In a 50 ml two-necked flask equipped with a nitrogen introduction tube and a stirrer, 1.00 g (6.66 mmol) of Me4APhA was measured and dissolved, and 16.38 g of NMP was added to dissolve it, and 1.89 g (6.39 mmol) of DI-2MG was added, and a nitrogen atmosphere It was reacted at 40°C for 24 hours. Thereby, a polymer (polymer solution: PRef-2) having a concentration of 15% by mass and a viscosity of 490 mPas was obtained. The weight average molecular weight of the obtained polymer was Mw: 41300.

<Preparation of liquid crystal aligning agent>

Example 9

In a 50 ml Erlenmeyer flask equipped with a stirrer, 10.0 g of the polymer (P-1) obtained in Example 4 was weighed, and 2.5 g of NMP, 5.0 g of GBL, and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, solid content 6.0 The liquid crystal aligning agent (AL-1) of mass %, NMP 44 mass %, GBL 20 mass %, and BCS 30 mass% was obtained.

Example 10

In a 50 ml Erlenmeyer flask equipped with a stirrer, 10.0 g of the polymer (P-2) obtained in Example 5 was weighed, and 2.5 g of NMP, 5.0 g of GBL, and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, and solid content 6.0 The liquid crystal aligning agent (AL-2) of mass %, NMP 44 mass %, GBL 20 mass %, and BCS 30 mass% was obtained.

Example 11

In a 50 ml Erlenmeyer flask equipped with a stirrer, 10.0 g of the polymer (P-3) obtained in Example 6 was weighed, and 2.5 g of NMP, 5.0 g of GBL, and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, solid content 6.0 The liquid crystal aligning agent (AL-3) of mass %, NMP 44 mass %, GBL 20 mass %, and BCS 30 mass% was obtained.

Example 12

In a 50 ml Erlenmeyer flask equipped with a stirrer, 10.0 g of the polymer (P-4) obtained in Example 7 was weighed, and 2.5 g of NMP, 5.0 g of GBL, and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, solid content 6.0 The liquid crystal aligning agent (AL-4) of mass %, NMP 44 mass %, GBL 20 mass %, and BCS 30 mass% was obtained.

Example 13

In a 50 ml Erlenmeyer flask equipped with a stirrer, 10.0 g of the polymer (P-5) obtained in Example 8 was weighed, 2.5 g of NMP, 5.0 g of GBL, and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, solid content 6.0 The liquid crystal aligning agent (AL-5) of mass %, NMP 44 mass %, GBL 20 mass %, and BCS 30 mass% was obtained.

Comparative Example 3

In a 50 ml Erlenmeyer flask equipped with a stirrer, 10.0 g of the polymer (PRef-1) obtained in Comparative Example 1 was weighed, and 2.5 g of NMP, 5.0 g of GBL, and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, solid content 6.0 The liquid crystal aligning agent (AL-6) of mass %, NMP 44 mass %, GBL 20 mass %, and BCS 30 mass% was obtained.

Comparative Example 4

In a 50 ml Erlenmeyer flask equipped with a stirrer, 10.0 g of the polymer (PRef-2) obtained in Comparative Example 2 was weighed, and 2.5 g of NMP, 5.0 g of GBL, and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, solid content 6.0 The liquid crystal aligning agent (AL-7) of mass %, NMP 44 mass %, GBL 20 mass %, and BCS 30 mass% was obtained.

Comparative Example 5

SE-6414 manufactured by Nissan Chemical Co., Ltd. was used as a liquid crystal aligning agent (AL-8).

Using the liquid crystal aligning agents (AL-1 to AL-5) of Examples 9 to 13 and the liquid crystal aligning agents (AL-6 to AL-8) of Comparative Examples 3 to 5, based on the following method, a liquid crystal aligning film is Evaluated.

<Evaluation of whitening resistance and coating property (printability)>

The obtained liquid crystal aligning agent was dropped by 1 drop each on the well-washed Cr substrate, left to stand at room temperature 25°C and humidity 60%, and the time until whitening (whitening) was measured. Based on the measured time, whitening resistance was evaluated.

After filtering the liquid crystal aligning agent with a 1.0 micrometer filter, the coating property test was performed by performing flexo printing on the cleaned Cr substrate using an alignment film printer ("Angstrom" made by Nippon Shashin Insats).

About 1.0 ml of a liquid crystal aligning agent was dripped on an anilox roll, and after performing idling 10 times, the printing machine was stopped for 10 minutes, and the printing plate was dried. Thereafter, printing was performed on one Cr substrate, and the printed substrate was left on a hot plate at 70° C. for 5 minutes to temporarily dry the coating film, and the film state was observed. At a magnification of 50 times with the naked eye and an optical microscope ("ECLIPSE ME600" manufactured by Nikon), the film thickness unevenness and the film thickness unevenness of the edge portion were mainly observed.

<Evaluation of liquid crystal orientation, voltage retention, and pretilt angle>

[Observation of liquid crystal orientation and production of liquid crystal cell]

After filtering the liquid crystal aligning agent with a filter of 1.0 µm, the electrode-attached substrate (a glass substrate having a size of 30 mm in width x 40 mm in length and a thickness of 1.1 mm. The electrode is a rectangle having a width of 10 mm x a length of 40 mm, and a thickness of 35 nm). ITO electrode) was applied by spin coat printing. After drying for 5 minutes on a 50°C hot plate, baking was performed in an IR oven at 180°C for 20 minutes to form a coating film having a thickness of 100 nm. After rubbing this film with rayon fabric (YA-20R manufactured by Kako Yoshikawa) (roller diameter: 120mm, roller rotation speed: 1000rpm, moving speed: 20mm/sec, press-fit length: 0.4mm), in pure water for 1 minute After washing by irradiating ultrasonic waves, removing water droplets by air blowing, it was dried at 80°C for 15 minutes to obtain a substrate with a liquid crystal aligning film.

After preparing two substrates with a liquid crystal aligning film, spreading a 4 µm spacer on the surface of the liquid crystal aligning film, printing a sealing agent from the top, and rubbing another substrate in the reverse direction and the film surface. After sticking so as to face each other, the sealing agent was cured to produce an empty cell. MLC-2041 (manufactured by Merck Corporation) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain a liquid crystal cell. Thereafter, after observing the liquid crystal orientation, the liquid crystal cell was heated at 110°C for 1 hour and left at 23°C overnight to obtain a liquid crystal cell for voltage retention measurement.

Using the liquid crystal cell for measuring the voltage retention obtained in the above procedure, a voltage of 1 V was applied for 60 µs at a temperature of 60°C, and the voltage after 166.7 ms was measured to determine how much the voltage is held. It was calculated as the voltage retention rate. In addition, for the measurement of the voltage retention rate, a VHR-1 voltage retention measurement device manufactured by Toyo Technica was used.

[Evaluation of pre-tilt angle]

For the measurement of the pretilt angle, an Axo Scan Muller matrix polarimeter manufactured by OptoMatrix was used.

[Evaluation of rubbing tolerance]

After filtering the liquid crystal aligning agent with a filter of 1.0 µm, the electrode-attached substrate (a glass substrate having a size of 30 mm x 40 mm and a thickness of 1.1 mm. The electrode is a rectangle 10 mm wide x 40 mm long, and an ITO electrode having a thickness of 35 nm) ), it was applied by spin coat printing. After drying for 5 minutes on a 50°C hot plate, baking was performed for 20 minutes in an IR oven at 180°C to form a coating film having a thickness of 100 nm. After rubbing this film with rayon fabric (YA-20R manufactured by Kako Yoshikawa) (roller diameter: 120mm, roller rotation speed: 1000rpm, moving speed: 20mm/sec, press fit length: 0.4mm), rubbing using a confocal laser microscope Tolerance was evaluated. When the film is peeled, x, when a lot of debris or scratches cut on the film is seen, △, when it is good (when the film is not peeled off, and when there are not many scraps or scratches cut on the film), set to ○. Table 1 shows the results of various evaluations.

[Table 1]

The liquid crystal aligning agent of Examples 9 to 13 was significantly superior in whitening resistance compared to the comparative example, and also good in printability. Since Comparative Example 5 is a polyamic acid-based material, it is a material system having good whitening resistance and printability. In Examples 9 to 13, it is expected that properties equivalent to or higher than those of Comparative Example 5 can be obtained in terms of whitening resistance and printability. The organic group represented by the formula (1-1) is considered to be consumed in reactions within the molecule or crosslinking between molecules, and thus, compared with Comparative Examples 3 and 4, Examples 9 to 13 have very good rubbing resistance. Do. In Comparative Example 5, since the imidation reaction did not proceed, it is considered that the rubbing resistance was poor.

Moreover, in the liquid crystal cell obtained using the liquid crystal aligning agent of Examples 9-13, a low pretilt angle and a high voltage retention are obtained. It can be considered that this is a result that the organic group represented by the formula (1-1) is used in various reactions and does not involve a decomposition reaction like polyamic acid. Therefore, the liquid crystal aligning film which is one aspect of this invention is considered to be very promising as a liquid crystal aligning film obtained by baking at low temperature. Moreover, even if any liquid crystal aligning agent of Examples 7-10 was used, a liquid crystal aligning film and a liquid crystal display element could be obtained suitably.

Industrial availability

The liquid crystal display element produced by using the liquid crystal aligning agent of the present invention can be a highly reliable liquid crystal display device, and can be suitably used for display elements by various methods, such as IPS liquid crystal display elements and FFS liquid crystal display elements. have.

Claims (9)

A liquid crystal aligning agent containing a polymer which is a polyurea and a polyurea copolymer having a structure represented by the following formula (1):
[Formula 1]

(In the formula, X represents a divalent organic group derived from a diisocyanate derivative, and Y represents a divalent organic group derived from a diamine derivative. R ₁ represents an alkyl group having 1 to 4 carbon atoms, and may be branched. R ₂ Represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, or an organic group represented by the following formula (1-1): Each of Ra and Rb independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 2 carbon atoms.
[Formula 2]

In the above formula, it is a black dot means a binding point of the nitrogen atom, and R _1, Ra and Rb are of the R _1, Ra and Rb and agreement (同意).). The method of claim 1,
A liquid crystal aligning agent containing a diamine derivative represented by the following formula (2) and a polymer which is a polyurea and a polyurea copolymer obtained from a diisocyanate derivative:
[Formula 3]

In the formula, A represents an aliphatic hydrocarbon group or a divalent organic group of an aromatic hydrocarbon group, B and C each independently represent a single bond or an aliphatic hydrocarbon group having 1 to 5 carbon atoms, R ₁ , R ₂ , Ra and Rb have the same meaning as R ₁ , R ₂ , Ra and Rb above. The method of claim 2,
A liquid crystal aligning agent containing a diamino compound represented by the following formula (3) among the diamine derivatives and a polyurea and a polyurea copolymer polymer obtained from a diisocyanate derivative:
[Formula 4]

In the formula, Ar represents an aryl group, D represents a single bond or a hydrocarbon group having 1 to 5 carbon atoms, and R ₁ , R ₂ , Ra and Rb are the same as those of R ₁ , R ₂ , Ra and Rb described above. The method of claim 3,
Among the diamine derivatives, a liquid crystal aligning agent containing a diamino compound represented by the following formula (3-a) and a polymer which is a polyurea and a polyurea copolymer obtained from a diisocyanate derivative:
[Formula 5]

Wherein, D and R ₁ is D and R ₁ and consent of the. A polymer obtained from a diamino compound represented by the following formula (3-1) and a diisocyanate derivative:
[Formula 6]

In the formula, R ₁ represents an alkyl group having 1 to 4 carbon atoms and may be branched, B represents a single bond or an aliphatic hydrocarbon group having 1 to 5 carbon atoms, and Ra and Rb are each independently a hydrogen atom or a carbon number 1 It shows the aliphatic hydrocarbon group of -2. The method of claim 5,
A polymer obtained from the diamino compound and at least one of the diisocyanate derivatives represented by the following formulas (4-1) to (4-11) and (4-13):
[Formula 7]

A liquid crystal aligning agent using the polymer according to claim 5 or 6. A liquid crystal aligning film obtained from the liquid crystal aligning agent in any one of Claims 1-4 and 7. A liquid crystal display element using the liquid crystal aligning film according to claim 8.