KR102505385B1 - Polymer and liquid crystal aligning agent using the same - Google Patents

Abstract

(X₁ ∼ X₃ 은 각각 독립적으로 테트라카르복실산 성분에서 유래하는 4 가의 유기기이다. Y₁ ∼ Y₃ 은, 각각 독립적으로 디아민에서 유래하는 2 가의 유기기이며, Y₁ ∼ Y₃ 의 적어도 1 개는 염기성기를 갖는다. R₁ 은 탄소수 1 ∼ 5 의 알킬기이다.)Since it has high solubility in organic solvents, various solvents can be selected, and the membranous material obtained therefrom provides a polymer having excellent properties as a liquid crystal aligning agent. A polymer having a repeating unit of polyamic acid ester, a repeating unit of polyimide, and a repeating unit of polyamic acid, and having a basic group in one of the repeating units.
[Formula 1]

(X ₁ to X ₃ are each independently a tetravalent organic group derived from a tetracarboxylic acid component. Y ₁ to Y ₃ are each independently a divalent organic group derived from diamine, and Y ₁ to Y ₃ At least one has a basic group, R ₁ is an alkyl group of 1 to 5 carbon atoms.)

Description

Polymer and liquid crystal aligning agent using the same

The present invention relates to, for example, a novel polymer suitable for a liquid crystal aligning agent and a liquid crystal aligning agent using the same.

In a liquid crystal display element used for a liquid crystal television, a liquid crystal display, or the like, a liquid crystal alignment film for controlling the arrangement of liquid crystals is usually formed inside the element.

At present, at least one kind of polymer selected from polyamic acid, polyamic acid ester, and polyimide is used for the liquid crystal aligning film that is most widely spread industrially from the viewpoints of the high reliability, liquid-crystal orientation, and the like.

A liquid crystal aligning film can be formed by apply|coating the liquid crystal aligning agent which melt|dissolved the above polymers in the organic solvent on a board|substrate, and baking.

However, there are few solvents that can sufficiently dissolve these polymers. Therefore, there exists a problem that a polymer precipitates when preserving a liquid crystal aligning agent at low temperature. Moreover, as a result of poor applicability to a board|substrate and a uniform liquid crystal aligning film not being obtained, there also exists a problem of giving a bad influence to the characteristic of a liquid crystal display element.

Regarding these problems, a liquid crystal aligning agent having excellent printability by introducing a structure having high solubility in an organic solvent has been proposed so far (see Patent Document 1 and Patent Document 2).

WO2008/062877 WO2014/034790

An object of this invention is to provide the polymer which can select various solvents since it has high solubility with respect to an organic solvent, and as a result, the obtained membranous material has excellent characteristics as a liquid crystal aligning agent.

The present inventors discovered that the said objective could be achieved with the polymer which has the repeating unit of polyamic acid ester and the repeating unit of a polyimide, as a result of repeating earnest examination in order to achieve the said objective.

That is, the gist of the present invention is as follows.

(1) A polymer having a repeating unit of polyamic acid ester, a repeating unit of polyimide, and a repeating unit of polyamic acid, and having a basic group in any of the repeating units.

(2) The repeating unit of the polyamic acid ester is represented by the following formula (1), the repeating unit of the polyimide is represented by the following formula (2), and the repeating unit of the polyamic acid is represented by the following formula (3) The polymer as described in said (1) shown.

[Formula 1]

(In the above formulas (1) to (3), X ₁ , X ₂ and X ₃ are each independently a tetravalent organic group derived from a tetracarboxylic acid component. Y ₁ , Y ₂ and Y ₃ are each It is a divalent organic group independently derived from diamine, and at least one of Y ₁ , Y ₂ , and Y ₃ has a basic group. R ₁ is an alkyl group having 1 to 5 carbon atoms.)

(3) The content of the repeating unit of the polyamic acid ester, the repeating unit of the polyimide, and the repeating unit of the polyamic acid is 10 to 90 mol%, 9 to 89 mol%, and 1 to 81 mol%, respectively. The polymer according to (1) or (2) above.

(4) The polymer according to any one of (1) to (3) above, wherein the basic group is a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a piperidine ring, or a piperazine ring. .

(5) The polymer according to any one of (2) to (4) above, wherein Y ₁ , Y ₂ and Y ₃ having the basic group are 5 to 90 mol% with respect to all Y ₁ , Y ₂ and Y ₃ . .

(6) The polymer according to any one of (2) to (5), wherein Y ₁ , Y ₂ and Y ₃ having the basic group are at least one selected from the group consisting of structures represented by the following formula.

[Formula 2]

(7) The polymer according to any one of (2) to (6) above, which is at least one selected from the group consisting of a structure in which X ₁ to X ₃ in formulas (1) to (3) are represented by the following formula .

[Formula 3]

(In the formula, R ₃ to R ₆ 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, an alkynyl group having 2 to 6 carbon atoms, and a fluorine-containing carbon atom of 1 to 6 It is a monovalent organic group of 6 or a phenyl group.)

(8) The liquid crystal aligning agent containing the polymer as described in any one of said (1)-(7).

(9) The liquid crystal aligning film obtained from the liquid crystal aligning agent of the said (8).

(10) A liquid crystal display element provided with the liquid crystal aligning film as described in said (9).

According to the present invention, because of its high solubility, various solvents can be selected, and as a result, a polymer capable of imparting a polymer solution with high printability to a substrate or the like is obtained. From the printability with respect to the board|substrate of the high solubility and the obtained polymer solution, the use with respect to the liquid crystal aligning agent which provides the liquid crystal aligning film which controls the orientation of the liquid crystal of the polymer of this invention is especially preferable.

The polymer of the present invention is a polymer (hereinafter, also referred to as a specific polymer) having a repeating unit of polyamic acid ester, a repeating unit of polyimide, and a repeating unit of polyamic acid, and having a basic group in the repeating unit.

The repeating unit of the polyamic acid ester contained in a specific polymer, the repeating unit of a polyimide, and the repeating unit of a polyamic acid can be represented by following formulas (1)-(3), respectively.

[Formula 4]

In the formulas (1) to (3), X ₁ , X ₂ and X ₃ are tetravalent organic groups derived from tetracarboxylic acid derivatives, and Y ₁ , Y ₂ and Y ₃ are divalent organic groups derived from diamines. It is an organic group, at least one of Y ₁ , Y ₂ , and Y ₃ has a basic group, and R ₁ is an alkyl group of 1 to 5 carbon atoms. In addition, X ₁ , X ₂ , X ₃ and Y ₁ , Y ₂ , Y ₃ , and furthermore, two R ₁ may be the same or different.

ADVANTAGE OF THE INVENTION According to this invention, about content of the repeating unit of the repeating unit of polyamic acid ester in a specific polymer, the repeating unit of the said polyimide, and the said polyamic acid, various things can be provided. Especially, since high solubility is obtained, each content of the repeating unit of a polyamic acid ester, the repeating unit of the said polyimide, and the repeating unit of the said polyamic acid is 10-90 mol%, 9-89 mol%, 1 It is preferable that it is -81 mol%, and also it is more preferable that it is 40-90 mol%, 9-59 mol%, and 1-51 mol%, respectively.

Hereinafter, the polymer which forms a specific polymer and those raw materials are explained in full detail.

<Tetracarboxylic acid component>

Examples of the tetracarboxylic acid component for obtaining a specific polymer include tetracarboxylic acid, tetracarboxylic dianhydride, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, or tetracarboxylic acid dialkyl ester dihalide. In the present invention, these are collectively referred to as tetracarboxylic acid components. Especially, as a raw material which manufactures a specific polymer, it is preferable to use tetracarboxylic dianhydride.

<Tetracarboxylic dianhydride>

As tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, etc. are mentioned, for example, It can represent with the following general formula.

[Formula 5]

In the formula, the structure of X is not particularly limited, and these are the same as the definitions of X ₁ , X ₂ and X ₃ in the repeating units of the above formulas (1) to (3). As a specific example, although the following formula (X1-1) - (X1-46) is illustrated, it is not limited to these.

[Formula 6]

In the above formula, R ³ to R ²³ each independently represent a hydrogen atom, a halogen atom, an alkyl group of 1 to 6 carbon atoms, an alkenyl group of 2 to 6 carbon atoms, an alkynyl group of 2 to 6 carbon atoms, and a fluorine-containing carbon atom of 1 to 6. It is a monovalent organic group of 6 or a phenyl group.

In the case of a liquid crystal aligning agent, in the case of a liquid crystal aligning agent, a hydrogen atom, a halogen atom, a methyl group, or an ethyl group is preferable, and, as for ^R3 - ^R6 in Formula (X1-1), a hydrogen atom or a methyl group is more preferable. Formula (X1-1) is preferably the following formula (X1-11) or (X1-12).

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

In addition, the said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

<diamine component>

The diamine component for obtaining the specific polymer of this invention is represented by the following formula [2].

[Formula 12]

In the above formula, A ₁ and A ₂ are each independently a hydrogen atom, an alkyl group of 1 to 5 carbon atoms, an alkenyl group of 2 to 5 carbon atoms, or an alkynyl group of 2 to 5 carbon atoms. In the case of a liquid crystal aligning agent, from a viewpoint of liquid-crystal orientation, _A1 and _A2 are preferably a hydrogen atom or a methyl group. The structure of Y is the same as the definition of Y ₁ , Y ₂ and Y ₃ in the repeating units of the formulas (1) to (3). If a specific example is given, it will be as follows, but it will not be limited to these.

[Formula 13]

[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]

[Formula 33]

In the above formula, n is an integer of 1 to 6, Me is a methyl group, and Boc represents a tert-butoxycarbonyl group.

<Diamine having a basic group>

Since the reaction at the time of manufacturing the specific polymer of this invention advances easily, the diamine which has a basic group is used for manufacture of a specific polymer. As a specific example of a basic group, a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a piperidine ring, or a piperazine ring is preferable. The basic group may be contained in the main chain of diamine or may be contained in the side chain.

Diamine having a basic group contains the structure of Y-71, Y-73, Y-96, Y-76, Y-77, Y-163, Y-164, Y-165 or Y-172 exemplified above Diamines are preferred. The structure derived from these diamines may be contained in any of the repeating units in the above formulas (1) to (3), or may be contained in a plurality of repeating units.

5-90 mol% of the whole diamine component used for manufacture of the specific polymer of this invention is preferable, and, as for preferable content of the said diamine which has a basic group, 10-70 mol% is more preferable.

<Method for producing polyamic acid>

The polyamic acid used for manufacture of a specific polymer can be manufactured with the following method.

Specifically, produced by reacting tetracarboxylic dianhydride and diamine in the presence of an organic solvent at -20 to 150°C, preferably 0 to 50°C for 30 minutes to 24 hours, preferably 1 to 12 hours can do.

The organic solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, γ-butyrolactone or the like in view of the solubility of monomers and polymers, and one or two or more of these are preferred. may be used in combination.

The concentration of the polymer 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.

The polyamic acid obtained as described above can precipitate and recover a polymer by injecting the reaction solution into a poor solvent while stirring it well. Further, a purified polyamic acid powder can be obtained by performing precipitation several times, washing with a poor solvent, and then drying at room temperature or by heating. Although the poor solvent is not particularly limited, water, methanol, ethanol, 2-propanol, hexane, butyl cellosolve, acetone, toluene and the like are exemplified, and water, methanol, ethanol, 2-propanol and the like are preferable.

<Method for producing polyimide>

The polyimide used for manufacture of a specific polymer can be manufactured by imidating the said polyamic acid. Moreover, polyimide can also be manufactured by imidation of polyamic acid ester.

In the case of producing polyimide from polyamic acid, chemical imidation by adding a catalyst to a solution of the polyamic acid obtained by the reaction of the diamine component and tetracarboxylic dianhydride is simple. Chemical imidation is preferable because the imidation reaction proceeds at a relatively low temperature and the molecular weight of the polymer does not decrease easily in the process of imidation.

Chemical imidation can be performed by stirring a polyamic acid in presence of a basic catalyst and an acid anhydride in an organic solvent. As the organic solvent, the solvent used in the polymerization reaction described above can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine is preferable because it has a suitable basicity for advancing the reaction. Moreover, acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. are mentioned as an acid anhydride, Since the refinement|purification after completion|finish of reaction becomes easy when acetic anhydride is used especially, it is preferable.

The temperature during the imidation reaction is -20 to 140°C, preferably 0 to 100°C, and the reaction time can be 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 times the mole, preferably 2 to 20 times the mole of the polyamic acid group, and the amount of the acid anhydride is 1 to 50 times the mole, preferably 3 to 30 times the mole of the polyamic acid group. The imidation rate of the resulting polymer can be controlled by adjusting the catalyst amount, temperature, and reaction time.

Since the added catalyst and the like remain in the solution after the imidation reaction of the polyamic acid, the obtained imidized polymer is recovered by the means described below, and redissolved in an organic solvent to make it the liquid crystal aligning agent of the present invention. desirable.

A polymer can be deposited by inject|pouring into a poor solvent, stirring well the solution of the polyimide obtained by performing it above. Precipitation is carried out several times, followed by washing with a poor solvent, followed by drying at room temperature or heat to obtain a purified imidized polymer powder.

Although the said poor solvent is not specifically limited, Methanol, 2-propanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, etc. are mentioned, methanol, ethanol , 2-propanol, acetone and the like are preferred.

<Manufacture of specific polymer via polyamic acid>

The specific polymer of the present invention is obtained by reacting the powder of an imidized polymer obtained by partially imidating the polyamic acid obtained above or a polymer solution obtained by dissolving the imidized polymer in an organic solvent, and esterifying the polymer.

Specifically, it is obtained by immersing the powder of the imidized polymer obtained above in alcohol or stirring it in alcohol. A powder of a specific polymer can be obtained by immersing in alcohol for 15 to 100 hours, preferably 15 to 50 hours. As for the temperature at the time of reaction, 20-60 degreeC is preferable. When stirring in alcohol, a powder of a specific polymer can be obtained in 5 to 100 hours, preferably 20 to 70 hours.

When adding and reacting the obtained polymer solution and alcohol by dissolving the powder of the imidized polymer obtained above in an organic solvent, the powder of a specific polymer can be obtained in 20 to 100 hours. Preferably it is 20 to 70 hours. As for the temperature at the time of reaction, 20-60 degreeC is preferable.

In the present invention, the repeating unit of the polyamic acid, the repeating unit of the polyimide, and the repeating unit of the polyamic acid ester are arbitrarily adjusted by arbitrarily adjusting the imidation ratio of the polyamic acid and also arbitrarily adjusting the esterification ratio of the imidide. A specific polymer containing as can be obtained.

<Manufacture of specific polymer via polyamic acid ester>

The specific polymer of this invention can also be obtained by first manufacturing polyamic acid ester and imidating this. Polyamic acid ester can be manufactured by the following (1) - (3) method.

(1) In the case of manufacturing from polyamic acid

Polyamic acid ester can be manufactured by esterifying the polyamic acid obtained from tetracarboxylic dianhydride and diamine. Specifically, it can be produced by reacting a polyamic acid and an esterification agent in the presence of an organic solvent at -20 to 150°C, preferably 0 to 50°C, for 30 minutes to 24 hours, preferably 1 to 4 hours. . Depending on the reaction conditions, a polymer having repeating units of polyamic acid and polyamic acid ester can be produced at the same time, and a polymer having repeating units of polyamic acid, polyimide and polyamic acid ester can also be produced by imidation thereof. there is.

The esterifying agent is preferably one that can be easily removed by purification, and N,N-dimethylformamide dimethyl acetal, N,N-dimethylformamide diethyl acetal, N,N-dimethylformamide dipropyl acetal, N,N-dimethylformamidedineopentylbutylacetal, N,N-dimethylformamidedi-t-butylacetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene , 1-propyl-3-p-tolyltriazene, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride, and the like. The addition amount of the esterifying agent is preferably 2 to 6 molar equivalents, more preferably 2 to 4 molar equivalents, per 1 mol of the repeating unit of the polyamic acid.

The organic solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, γ-butyrolactone or the like in terms of polymer solubility, and these are used alone or in combination of two or more. You may use it. The concentration of the polymer in the organic solvent at the time of production is preferably 1 to 30% by mass, and more preferably 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. .

(2) When produced by the reaction of tetracarboxylic acid diester dichloride and diamine

Polyamic acid ester can be manufactured from tetracarboxylic acid diester dichloride and diamine. Specifically, tetracarboxylic diester dichloride and diamine are mixed in the presence of a base and an organic solvent at -20 to 150°C, preferably 0 to 50°C, for 30 minutes to 24 hours, preferably 1 to 4 It can be manufactured by time reaction.

Although pyridine, triethylamine, 4-dimethylaminopyridine, etc. can be used for the said base, since reaction advances mildly, pyridine is preferable. The added amount of the base is preferably 2 to 4 moles, more preferably 2 to 3 moles, relative to tetracarboxylic diester dichloride, from the viewpoint of easy removal and easy obtaining of a high molecular weight body.

As for the organic solvent used for the said reaction, N-methyl-2-pyrrolidone, (gamma)-butyrolactone, etc. are preferable from the solubility of a monomer and a polymer, and you may use these 1 type or in mixture of 2 or more types. The polymer concentration in the organic solvent at the time of production is preferably 1 to 30% by mass, and more preferably 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. In addition, in order to prevent hydrolysis of tetracarboxylic acid diester dichloride, it is preferable that the organic solvent used in the production of polyamic acid ester is dehydrated as much as possible, and the reaction is carried out in a nitrogen atmosphere, incorporating outside air. It is desirable to prevent

(3) When produced from tetracarboxylic acid diester and diamine

Polyamic acid ester can be manufactured by polycondensing tetracarboxylic-acid diester and diamine. Specifically, a tetracarboxylic diester and a diamine are mixed in the presence of a condensing agent, a base, and an organic solvent at 0 to 150°C, preferably 0 to 100°C, for 30 minutes to 24 hours, preferably 3 to 15 hours. It can be manufactured by time reaction.

The condensing agent includes triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N,N'-carbonyldiimidazole, dimethoxy-1 ,3,5-triazinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, O-(benzotriazole- 1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzooxazolyl)phosphonic acid diphenyl, etc. can The amount of the condensing agent added is preferably 2 to 3 moles, more preferably 2 to 2.5 moles, based on the amount of the tetracarboxylic acid diester.

Tertiary amines such as pyridine and triethylamine can be used for the base. 2-4 times mole is preferable with respect to the diamine component, and, as for the addition amount of a base, 2-4 times mole is more preferable with respect to a diamine component from a viewpoint that a removal is an easy amount and a high molecular weight body is easy to be obtained.

Examples of the organic solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, and N,N-dimethylformamide.

In the above reaction, the reaction proceeds efficiently by adding a Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The added amount of the Lewis acid is preferably 0 to 1.0 times mole, more preferably 2.0 to 3.0 times mole relative to the diamine component.

Since high molecular weight polyamic acid ester is obtained among the manufacturing methods of the said 3 polyamic acid ester, the manufacturing method of said (1) or said (2) is especially preferable.

A polymer can be deposited by inject|pouring into a poor solvent, stirring well the solution of the polyamic acid ester obtained by performing it above. After performing precipitation several times, washing|cleaning with a poor solvent, it is made to dry at normal temperature or heat, and can obtain the powder of the polyamic acid ester refine|purified. Although the said poor solvent is not specifically limited, Water, methanol, ethanol, 2-propanol, hexane, a butyl cellosolve, acetone, toluene, etc. are mentioned, Water, methanol, ethanol, 2-propanol, etc. are preferable.

When a specific polymer is produced by imidizing the polyamic acid ester obtained in this way, chemical imidation by adding a basic catalyst to the polyamic acid ester solution or the polyamic acid solution obtained by dissolving the polyamic acid ester resin powder in an organic solvent is simple. . Chemical imidation is preferable because the imidation reaction proceeds at a relatively low temperature and the molecular weight of the polymer does not decrease easily in the process of imidation.

Chemical imidation can be performed by stirring polyamic acid ester in basic catalyst presence in an organic solvent. As the organic solvent, the solvent used in the polymerization reaction described above can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, triethylamine is preferred because it has sufficient basicity to advance the reaction.

The temperature during the imidation reaction is -20 to 140°C, preferably 0 to 100°C, and the reaction time can be 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 times mole of the amic acid ester group, preferably 2 to 20 times mole. The imidation rate of the resulting polymer can be controlled by adjusting the catalyst amount, temperature, and reaction time.

A specific polymer can be obtained by imidating polyamic acid ester as mentioned above and adjusting the imidation rate at that time.

<liquid crystal aligning agent>

Although the specific polymer of this invention can be used for various uses, when the high solubility, the excellent characteristics of the obtained film|membrane, etc. are considered, use as a liquid crystal aligning agent is preferable.

The liquid crystal aligning agent has a form of a solution in which a specific polymer is dissolved in an organic solvent. The molecular weight of the specific polymer is preferably from 2,000 to 500,000, more preferably from 5,000 to 300,000, still more preferably from 10,000 to 100,000 in terms of weight average molecular weight (Mw). Also, the number average molecular weight (Mn) is preferably from 1,000 to 250,000, more preferably from 2,500 to 150,000, still more preferably from 5,000 to 50,000.

The concentration of the specific polymer in the liquid crystal aligning agent can be appropriately changed according to the setting of the thickness of the coating film to be formed, but is preferably 1% by mass or more from the viewpoint of forming a uniform and defect-free coating film, and preservation of the solution. From the point of stability, 10 mass % or less is preferable. A particularly preferred concentration of the polymer is 2 to 8% by mass.

The organic solvent contained in a liquid crystal aligning agent will not be specifically limited if a polymer component melt|dissolves uniformly. For specific examples, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone , N-methylcaprolactam, 2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethylsulfoxide, dimethylsulfone, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, 3-methyl Toxy-N,N-dimethylpropanamide etc. are mentioned. You may use these 1 type or in mixture of 2 or more types. Moreover, even if it is a solvent which cannot uniformly dissolve the polymer component alone, it may be mixed with the organic solvent as long as the polymer does not precipitate.

A liquid crystal aligning agent may contain the solvent for improving the coating film uniformity at the time of apply|coating a liquid crystal aligning agent to a board|substrate other than the organic solvent for dissolving a specific polymer component. These solvents generally have a lower surface tension than the organic solvents and are poor solvents with lower solubility. However, the specific polymer of the present invention is advantageously used also for these solvents because of its high solubility. Specific examples thereof include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol , 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether -2-acetate, butyl cellosolve acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, methyl lactate ester, ethyl lactate ester, n-propyl lactate ester, n-butyl lactate ester, isobaric acid lactate Wheat ester etc. are mentioned. These solvents may use 2 or more types together.

In the liquid crystal aligning agent, in addition to the above, polymers other than specific polymers, dielectrics or conductive materials for the purpose of changing electrical properties such as dielectric constant or conductivity of the liquid crystal aligning film, silane coupling agent for the purpose of improving the adhesion between the liquid crystal aligning film and the substrate, liquid crystal You may add a crosslinkable compound for the purpose of increasing the hardness and density of the film when it is used as an alignment film, and also an imidation accelerator for the purpose of efficiently advancing imidation of the polyamic acid when firing the coating film.

A liquid crystal aligning film is a film obtained by apply|coating a liquid crystal aligning agent to a board|substrate, drying, and baking. The substrate to which the liquid crystal aligning agent is applied is not particularly limited as long as it is a substrate having high transparency, and a plastic substrate such as an acrylic substrate or a polycarbonate substrate may be used in addition to a glass substrate or a silicon nitride substrate. In that case, it is preferable to use a substrate having an ITO electrode or the like for driving the liquid crystal in view of simplifying the process. In addition, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as it is only used as a substrate on one side, and a material that reflects light such as aluminum can also be used for the electrode in this case.

Although the coating method of a liquid crystal aligning agent is not specifically limited, Industrially, the method of performing by screen printing, offset printing, flexographic printing, or an inkjet method is common. Other coating methods include a dip method, a roll coater method, a slit coater method, a spinner method, or a spray method, and these may be used depending on the purpose.

After applying the liquid crystal aligning agent on the substrate, the solvent can be evaporated by a heating means such as a hot plate, a heat circulation type oven or an IR (infrared ray) type oven to form a liquid crystal alignment film. The drying and baking process after apply|coating the liquid crystal aligning agent of this invention can select arbitrary temperature and time. Usually, in order to fully remove the contained solvent, the conditions of baking at 50-120 degreeC for 1 to 10 minutes, and then baking at 150-300 degreeC for 5-120 minutes are mentioned. Since the reliability of a liquid crystal display element may fall when the thickness of the liquid crystal aligning film after baking is too thin, 5-300 nm is preferable and 10-200 nm is more preferable.

The method of orientation-processing the liquid crystal aligning film obtained from a liquid crystal aligning agent is not specifically limited. As the rubbing treatment method, an existing rubbing method or apparatus can be used. Examples of the material of the rubbing cloth include cotton, rayon, nylon, and polyester. For example, as shown in Japanese Unexamined Patent Publication No. 55-143525, as a liquid crystal alignment substrate, an alignment film coated on a transparent electrode substrate is used, and the rubbing cloth is applied to a roller on the alignment film surface. ) A method of obtaining uniform liquid crystal alignment by rubbing with a rubbing machine is widely used as a rubbing method.

In the case of the photo-alignment treatment method, the surface of the liquid crystal alignment film is irradiated with radiation deflected in a certain direction, and in some cases, preferably a heat treatment is performed at a temperature of 150 to 250 ° C. ) can be given. As radiation, ultraviolet rays or visible rays having a wavelength of 100 to 800 nm can be used. Among them, it is an ultraviolet ray having a wavelength of preferably 100 to 400 nm, more preferably 200 to 400 nm.

Moreover, in order to improve liquid-crystal orientation, you may irradiate a radiation, heating the board|substrate on which the liquid crystal aligning film was coated at 50-250 degreeC. Moreover, as for the irradiation amount of the said radiation, 1-10,000 mJ/cm<2> is preferable. Especially, 100-5,000 mJ/cm<2> is preferable. The liquid crystal aligning film produced in this way can orientate liquid crystal molecules stably in a fixed direction.

The higher the extinction ratio of the polarized ultraviolet rays is, the higher the anisotropy can be imparted, which is preferable. Specifically, the extinction ratio of linearly polarized ultraviolet rays is preferably 10:1 or higher, and more preferably 20:1 or higher. Moreover, it is also possible to perform a contact treatment using water or a solvent on the liquid crystal aligning film irradiated with polarized radiation in the above method.

It will not specifically limit, if it is a solvent which melt|dissolves the decomposition product produced|generated from the liquid crystal aligning film by irradiation of a radiation as a solvent used for the said contact process. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate , diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, or cyclohexyl acetate. Among them, water, 2-propanol, 1-methoxy-2-propanol or ethyl lactate is preferable from the viewpoint of versatility and safety of the solvent. More preferred are water, 1-methoxy-2-propanol or ethyl lactate. One type of solvent may be sufficient, and it may combine two or more types.

As the said contact treatment, ie, the process of water or a solvent to the liquid crystal aligning film which irradiated the polarized radiation, an immersion process and a spray process (it is also mentioned a spray process) are mentioned. It is preferable that the processing time in these processes is 10 second - 1 hour from the point which melt|dissolves the degradation product produced|generated from the liquid crystal aligning film by radiation efficiently. Especially, it is preferable to perform immersion treatment for 1 minute to 30 minutes. In addition, the solvent at the time of the said contact treatment may be normal temperature or may be heated, but it is preferably 10-80 degreeC. Especially, 20-50 degreeC is preferable. In addition, you may perform ultrasonic treatment etc. as needed from the point of the solubility of the degradation product.

It is preferable to perform rinsing (it is also mentioned rinse) by low boiling point solvents, such as water, methanol, ethanol, 2-propanol, acetone, or methyl ethyl ketone, and baking of a liquid crystal aligning film after the said contact process. At that time, either one of rinsing and baking may be performed, or both may be performed. The firing temperature is preferably 150 to 300°C. Especially, 180-250 degreeC is preferable. More preferably, it is 200-230 degreeC. Moreover, as for the baking time, 10 second - 30 minutes are preferable. Especially, 1 to 10 minutes are preferable.

The liquid crystal aligning film of this invention is suitable as a liquid crystal aligning film of the liquid crystal display element of various orientation systems, such as a PSA system, an IPS system, and a FFS system. After a liquid crystal display element obtains the board|substrate with a liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention, it produces a liquid crystal cell by a known method, and is obtained using this liquid crystal cell.

As an example of the manufacturing method of a liquid crystal cell, a liquid crystal display element of a passive matrix structure is taken as an example and demonstrated. Alternatively, it may be a liquid crystal display element having an active matrix structure in which switching elements such as TFT (Thin Film Transistor) are formed in each pixel portion constituting the image display.

Specifically, a transparent glass substrate is prepared, and 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 so that desired image display can be performed. Next, an insulating film is formed on each substrate so as to cover 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 substrate, the other substrate is overlaid on one substrate so that the liquid crystal alignment film surfaces are opposed to each other, and the periphery is adhered with a sealant. In order to control the gap between the substrates, the sealant is usually mixed with a spacer, and it is preferable to spread the spacer for controlling the gap between the substrates also in the in-plane portion where the sealant is not formed. An opening portion capable of being filled with liquid crystal from the outside is formed in a part of the sealant. Next, the liquid crystal material is injected into the space surrounded by the two substrates and the sealant through an opening formed in the sealant, and then the opening is sealed with an adhesive. For injection, a vacuum injection method may be used, or a method using capillarity in the air may be used. As the liquid crystal material, either a positive liquid crystal material or a negative liquid crystal material may be used. Next, the polarizing plate is installed. Specifically, a pair of polarizing plates is attached to the surfaces of the two substrates opposite to the liquid crystal layer.

As mentioned above, the liquid crystal aligning film which suppresses the afterimage by alternating-current drive and makes adhesiveness with a sealing compound and a base substrate compatible can be obtained. In particular, it is useful with respect to a liquid crystal aligning film obtained by irradiating polarized radiation.

Example

The present invention will be described more specifically by way of examples below, but the present invention is not limited thereto. The symbol of the compound and the measurement method of each characteristic in the following are as follows.

<Tetracarboxylic dianhydride>

CBDA: 1,2,3,4-cyclobutane tetracarboxylic dianhydride

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

<diamine>

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

p-PDA: paraphenylenediamine

PCH7DAB: 1,3-diamino-4-[4-(trans-4-n-heptylcyclohexyl)phenoxy]benzene

<organic solvent>

MP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve

<Measurement of molecular weight>

A normal temperature gel permeation chromatography (GPC) apparatus (GPC-101) manufactured by Showa Denko Co., Ltd. and a column manufactured by Shodex (KD-803, KD-805) were used. Measurement conditions are as follows.

column temperature: 50 °C;

Eluent: N,N'-dimethylformamide (additive: 30 mmol/L of lithium bromide-hydrate (LiBr H ₂ O), 30 mmol/L of phosphoric acid/anhydrous crystal (o-phosphoric acid), tetrahydrofuran (THF) ) is 10 ml / L), flow rate: 1.0 ml / min,

Standard samples for calibration curve preparation: TSK manufactured by Tosoh Corporation, standard polyethylene oxides (molecular weights of about 900,000, 150,000, 100,000, and 30,000), and polyethylene glycols manufactured by Polymer Laboratory (molecular weights of about 12,000, 4,000, and 1,000).

<Measurement of imidization rate>

20 mg of polyimide powder was placed in an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Scientific Co., Ltd.), 0.53 ml of deuterated dimethylsulfoxide (a mixture of DMSO-d6 and 0.05% TMS (tetramethylsilane)) was added, Ultrasound was applied to dissolve completely. About this solution, the 500-MHz proton NMR was measured using the NMR measuring instrument by the JEOL datum company (JNW-ECA500). For the imidation rate, a proton derived from a structure that does not change before and after imidation is determined as a reference proton, and the peak integration value of this proton and the proton peak integration derived from the NH group of amic acid appearing around 9.0 to 11.0 ppm value was obtained by the following formula (1).

Imidization rate (%) = (1-α x / y) x 100 ... (1)

In the above formula (1), x is the proton peak integration value derived from the NH group of the amic acid, y is the peak integration value of the standard proton, and α is the polyamic acid (imidation rate is 0%) Amic acid in the case of It is the ratio of the number of reference protons to one NH group proton of

<Measurement of imidation rate, esterification rate, and amide rate of a specific polymer>

The IR spectrum of the polyimide powder is measured by the KBR method. The absorption peak (benzene ring) height (a1) around 1500 cm ^-1 and the absorption peak (imide ring) height ( ^b1 ) around 1380 cm -1 are measured to calculate b1/a1. Next, the IR spectrum of the specific polymer powder was measured by the KBR method, and the absorption peak (benzene ring) height (a2) around 1500 cm ^-1 and the absorption peak (imide ring) height (b2) around 1380 cm ^-1 were measured. By measuring, b2/a2 is calculated.

The imidation rate, esterification rate, and amide rate of a specific polymer were obtained by the following formulas (1) to (3). In the following formula (1), β is the imidation rate (%) of the polyimide powder.

Imidization rate (%) = ((b2/a2)/(b1/a1)) × β... (1)

Esterification rate (%) = β-((b2/a2)/(b1/a1) × β)... (2)

Amide rate (%) = 100-β... (3)

In other words, the imidation rate, esterification rate, and amide rate of a specific polymer show the content of the repeating unit of polyimide, the repeating unit of polyamic acid ester, and the repeating unit of polyamic acid in the specific polymer.

<Example 1>

BODA (2.50 g, 10 mmol), PCH7DAB (3.81 g, 10 mmol), 3-AMPDA (4.85 g, 20 mmol), p-PDA (2.16 g, 20 mmol) were mixed in NMP (75.46 g) to 80 After making it react at degreeC for 5 hours, CBDA (7.75g, 39.5mmol) and NMP (8.79g) were added, it was made to react at 40 degreeC for 6 hours, and the polyamic-acid solution was obtained.

After adding NMP to this polyamic-acid solution (20.0g) and diluting so that content of a polyamic acid might be 10 mass %, acetic anhydride (2.42g) and pyridine (0.62g) were added as an imidation catalyst, and 60 degreeC reacted for 3.5 hours. This reaction solution was poured into methanol (300 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder. The imidation rate of this polyimide was 75%, the number average molecular weight was 9651, and the weight average molecular weight was 23793.

The obtained polyimide powder was reprecipitated in methanol and stirred at 60°C for 20 hours. The precipitate was separated by filtration and dried under reduced pressure at 100°C to obtain a specific polymer powder. The imidation rate of this specific polymer was 33%, the esterification rate was 42%, the amide rate was 25%, and the number average molecular weight was 8314 and the weight average molecular weight was 18060.

<Example 2>

The polyimide powder obtained in Example 1 was reprecipitated in methanol and stirred at 60°C for 40 hours. The precipitate was separated by filtration and dried under reduced pressure at 100°C to obtain a specific polymer powder. The imidation rate of this specific polymer was 27%, the esterification rate was 48%, and the amide rate was 25%, and the number average molecular weight was 9171 and the weight average molecular weight was 24207.

<Example 3>

The polyimide powder obtained in Example 1 was reprecipitated in methanol and stirred at 60°C for 70 hours. The precipitate was separated by filtration and dried under reduced pressure at 100°C to obtain a specific polymer powder. The imidation rate of this specific polymer was 19%, the esterification rate was 56%, and the amide rate was 25%, and the number average molecular weight was 8366 and the weight average molecular weight was 20488.

<Comparative Example 1>

The polymer constituting the polyimide powder that is the intermediate polymer in Example 1 and used as a raw material for esterification was set as Comparative Example 1.

<Comparative Example 2>

It was the intermediate polymer in Example 1, and the polyamic acid polymer contained in the polyamic acid solution used as the raw material of imidation was made into the comparative example 2.

<Solubility test of specific polymer>

NMP was added and dissolved in the specific polymer powder, polyimide powder, and polyamic acid solution to obtain a polymer liquid having a polymer concentration of 10% without turbidity or precipitates. BCS (butyl cellosolve), a poor solvent, was added to the polymer solution until cloudiness or precipitates were formed, and the solubility of each polymer was evaluated from the amount of BCS added. The results are shown in the table below.

Compared with polyimide or polyamic acid, the specific polymer of the present invention confirmed that the solubility of the polymer was high because the addition amount of the poor solvent was large.

○: Cloudiness or precipitates are not observed in the polymer liquid.

x: Turbidity or a precipitate is observed in the polymer liquid.

The specific polymer according to the present invention can be used in various fields including liquid crystal compounding agents.

In addition, all the content of the Japanese Patent Application No. 2017-056384, claims, drawings, and abstract for which it applied on March 22, 2017 is referred here, and it takes in as an indication of the specification of this invention.

Claims (14)

It has a repeating unit of polyamic acid ester, a repeating unit of polyimide, and a repeating unit of polyamic acid,
The content of the repeating unit of the polyamic acid ester, the repeating unit of the polyimide, and the repeating unit of the polyamic acid is 48 to 90 mol%, 9 to 27 mol%, and 1 to 25 mol%, respectively,
Furthermore, a polymer having a basic group in one of the repeating units. According to claim 1,
The repeating unit of the polyamic acid ester is represented by the following formula (1), the repeating unit of the polyimide is represented by the following formula (2), and the repeating unit of the polyamic acid is represented by the following formula (3), polymer.

(In formulas (1) to (3), X ₁ , X ₂ and X ₃ are each independently a tetravalent organic group derived from a tetracarboxylic acid component. Y ₁ , Y ₂ and Y ₃ are each independently is a divalent organic group derived from diamine, and at least one of Y ₁ , Y ₂ , and Y ₃ has a basic group. R ₁ is an alkyl group having 1 to 5 carbon atoms.) According to claim 2,
A polymer in which X ₁ to X ₃ in formulas (1) to (3) is at least one member selected from the group consisting of aliphatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride. According to claim 1,
The polymer, wherein the basic group is a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a piperidine ring or a piperazine ring. According to claim 2,
A polymer in which Y ₁ , Y ₂ and Y ₃ having the basic group are 5 to 90 mol% with respect to all of Y ₁ , Y ₂ and Y ₃ . According to claim 2,
A polymer in which Y ₁ , Y ₂ and Y ₃ having the basic group are at least one selected from the group consisting of structures represented by the following formula.

According to claim 2,
A polymer in which X ₁ to X ₃ in formulas (1) to (3) are at least one selected from the group consisting of structures represented by the following formulas.

(In the above formula, R ₃ to R ₆ 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, an alkynyl group having 2 to 6 carbon atoms, and a fluorine atom containing 1 carbon atom to 6 monovalent organic group or phenyl group.) According to claim 7,
A polymer in which X ₁ to X ₃ in formulas (1) to (3) are at least one selected from the group consisting of structures represented by the following formulas.

(In the above formula, R ₃ to R ₆ have the same meaning as defined above.) The liquid crystal aligning agent containing the polymer in any one of Claims 1-8. The liquid crystal aligning film obtained from the liquid crystal aligning agent of Claim 9. A liquid crystal display element provided with the liquid crystal aligning film of Claim 10. delete delete delete