WO2019139115A1

WO2019139115A1 - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element

Info

Publication number: WO2019139115A1
Application number: PCT/JP2019/000652
Authority: WO
Inventors: 奈穂国見; 正人森内
Original assignee: 日産化学株式会社
Priority date: 2018-01-15
Filing date: 2019-01-11
Publication date: 2019-07-18
Also published as: TW201938771A; JP2021047214A

Abstract

The present invention relates to a liquid crystal aligning agent characterized by containing an organic solvent and a polymer selected from among: polyamic acids obtained using a tetracarboxylic acid dianhydride component and a diamine component containing a diamine represented by formula (1); and imidized products of the polyamic acids. In formula (1), R¹, R², R³ and R⁴ each independently denote H, CH₃ or CF₃, but one of R¹, R², R³ and R⁴ must be CH₃ or CF₃, W₁ and W₂ each denote a phenylene group, L1 and L2 each independently denote a divalent group represented by -(O)_n1-(CH₂)_m-(O)_n2-, n1 and n2 are each independently 0 or 1, and m is an integer between 1 and 10. The present invention can provide a liquid crystal aligning agent which is capable of producing a liquid crystal alignment film by means of a photo-alignment method and which gives a liquid crystal alignment film having a good voltage retention rate even when a backlight is continuously illuminated for a long period of time.

Description

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

The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element which give a liquid crystal aligning film excellent in voltage holding characteristics of a liquid crystal cell.

A general liquid crystal display element is configured by sandwiching a liquid crystal which changes direction in response to an electric field between a pair of transparent substrates provided with electrodes for applying the electric field to the liquid crystal. And a liquid crystal aligning film is one of the members which comprise a liquid crystal display element, Comprising: It is formed in the surface which contact | connects the liquid crystal of the said pair of board | substrates, The role of aligning the liquid crystal in contact with a liquid crystal aligning film in a fixed direction. Is responsible for

As a method of producing a liquid crystal alignment film, a rubbing method in which the surface of an organic film formed on a substrate is rubbed with a cloth on which fibers such as cotton, nylon and polyester are flocked is formed in a fixed direction, an organic film formed on a substrate An optical alignment method is known which imparts anisotropy to a film structure by irradiating the film with polarized ultraviolet light.

A decomposition type photoalignment method is known as one of the above photoalignment methods. For example, it is a method in which a polyimide film is irradiated with polarized ultraviolet light, anisotropic decomposition is caused by utilizing the polarization direction dependency of ultraviolet absorption of molecular structure, and liquid crystal is aligned with polyimide left without decomposition. (See, for example, Patent Document 1).

As a method of forming a polyimide film for forming a liquid crystal alignment film on a substrate, a method of applying a liquid crystal alignment agent containing polyamic acid which is a polyimide precursor on a substrate and baking it to form a polyimide film, or solvent solubility A liquid crystal aligning agent containing an imide group containing polyamic acid using an imide group containing diamine is coated on a substrate other than a method of applying a liquid crystal aligning agent containing a polyimide on a substrate and removing a solvent to form a polyimide film. Methods are known (see, for example, Patent Document 2).

Also, after a liquid crystal aligning agent containing an imide group-containing polyamic acid as described above is applied and dried on a substrate, then I) light is irradiated and then fired, or II) light is irradiated while firing Alternatively, a method for producing a photo alignment film including the step of irradiating light after firing and III) has been proposed (see Patent Document 3).

Unexamined-Japanese-Patent No. 9-297313 gazette JP-A-9-185064 WO 2017/057854

In recent years, with the change of the use form of the liquid crystal display element, the liquid crystal display element which can endure a long time use has been required. In order to be able to use for a long time, it is required that the characteristics do not change even if the light from the backlight unit is irradiated for a long time. Therefore, the liquid crystal alignment film in which the display characteristics do not largely change by the irradiation of the back light has come to be required.
In addition, the liquid crystal alignment film produced by the step of applying and drying a liquid crystal aligning agent containing a polyamic acid on a substrate, and then irradiating it with polarized ultraviolet light and then baking does not necessarily have sufficient stability of the liquid crystal alignment. In a liquid crystal display element driven by an in-plane switching mode, liquid crystal molecules are switched in-plane, so that alignment deviation of the liquid crystal after liquid crystal drive tends to occur, and good residual image characteristics can not be obtained due to this liquid crystal alignment deviation. There was a problem.

From the above, the first object of the present invention is to produce a liquid crystal alignment film by a photoalignment method, and still have a good voltage holding ratio even when the backlight light is continuously irradiated for a long time Another object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal alignment film, and further providing a liquid crystal aligning agent capable of obtaining a liquid crystal alignment film having a small decrease in voltage holding ratio even when back light is applied for a long time. A second object of the present invention is, in addition to the first object, a liquid crystal alignment film which can obtain a liquid crystal alignment film having good residual image characteristics even if it is a liquid crystal alignment film manufactured by a step of irradiating light and then baking. To provide the agent.

MEANS TO SOLVE THE PROBLEM As a result of conducting earnest examination, in order to solve the said subject, the present inventors discovered that said subject could be solved by using a specific diamine, and completed this invention.
Thus, the present invention is based on the above findings and has the following summary.

<1> A polymer selected from a polyamic acid obtained by using a tetracarboxylic acid dianhydride component and a diamine component containing a diamine represented by the following formula (1), an imidate thereof, and an organic solvent A liquid crystal aligning agent characterized by

During the ceremony
R ¹ , R ² , R ³ and R ⁴ each independently represent H, CH ₃ or CF ₃ , provided that ^one of R ¹ , R ² , R ³ and R ⁴ is necessarily CH ₃ or CF ₃ Represents
W ₁ and W ₂ represent phenylene, and phenylene is a halogen group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, a hydroxyl group, cyano Group, a dialkylamino group (the alkyl group is each independently a linear or branched alkyl group having 1 to 10 carbon atoms), a linear or branched ester group having 1 to 10 carbon atoms, or 1 carbon atom And may be substituted with a substituent selected from the group consisting of to 10 linear or branched acyl groups, carboxyl groups, aldehyde groups, nitro groups, and Boc-protected amino groups,
L1 and L2 are _{_{independently, - (O) n1 - (}} CH 2) m - (O) n2 - is a divalent group represented by, n1 and n2 are independently 0 or 1, m Is an integer of 1 to 10.

The liquid crystal aligning agent of said <1> whose at least one of n1 and n2 is 0 in each of L1 and L2 of <2> Formula (1).

The liquid crystal aligning agent of said <1> whose value of n1 + n2 + m is an even number in each of L1 and L2 of <3> Formula (1).

<4> The liquid crystal aligning agent according to any one of <1> to <3>, wherein 10 to 100 mol% in the diamine component is a diamine represented by the formula (1).

<5> A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of the above <1> to <4>.

<6> A liquid crystal display device having the liquid crystal alignment film of <5>.

The liquid crystal alignment film obtained by the light alignment method from the liquid crystal alignment agent of this invention can obtain the liquid crystal display element which has a favorable voltage holding ratio, even if it continues irradiating back light for a long time.

The liquid crystal aligning agent of the present invention is a polymer selected from a polyamic acid obtained by using a diamine component containing a specific diamine and a tetracarboxylic acid dianhydride component and its imidate (hereinafter also referred to as a specific polymer), and It is a liquid crystal aligning agent containing an organic solvent. Each condition will be described in detail below.

<Specific diamine>
The specific diamine used in the present invention is a diamine represented by the following formula (1).

In formula (1), R ¹ , R ² , R ³ and R ⁴ each independently represent H, CH ₃ or CF ₃ , provided that ^one of R ¹ , R ² , R ³ and R ⁴ is necessarily one Represents CH ₃ or CF ₃ . Preferably, ^{two of} R ¹ , R ² , R ³ and R ⁴ are CH ₃ and the remainder is H. More preferably, R ¹ and R ⁴ or R ² and R ³ are CH ₃ and the remainder is H. These are preferable from the point that the solubility of the obtained polymer is high.

In formula (1), W ₁ and W ₂ represent phenylene, preferably 1,4-phenylene. The phenylene is a halogen group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, a hydroxyl group, a cyano group or a dialkylamino group (wherein Each alkyl group is independently a linear or branched alkyl group having 1 to 10 carbon atoms), a linear or branched ester group having 1 to 10 carbon atoms, a linear or branched chain having 1 to 10 carbon atoms It may be substituted by a substituent selected from the group consisting of a branched chain acyl group, a carboxyl group, an aldehyde group, a nitro group, and a Boc-protected amino group.

In the formula (1), the L1 and L2 _{_{independently, - (O) n1 - (}} CH 2) m - (O) n2 - is a divalent group represented by 0 n1 and n2 independently Or 1 and m is an integer of 1 to 10.

Although the preferable structure of the diamine represented by Formula (1) below is mentioned, this invention is not limited to these.

In the formulas (1-1) to (1-4), m is an integer of 1 to 10.

Here, it is preferable that at least one of n1 and n2 is 0 in each of L1 and L2 in the formula (1), from the viewpoint of less decrease in voltage holding ratio when the backlight is irradiated for a long time. That is, n1 + n2 is preferably 0 or 1 in each of L1 and L2. Taking the above structure as an example, the structure represented by the formula (1-1), (1-2) or (1-4) is preferable.

In addition, even when the liquid crystal alignment film is produced by the step of applying the liquid crystal aligning agent of the present invention on a substrate, and then irradiating it with polarized ultraviolet light and baking it, the formula ( In each of L1 and L2 of 1), the value of n1 + n2 + m is preferably an even number. Taking the above structure as an example, m is preferably an odd number in the formulas (1-1) and (1-2), and m is an even number in the formulas (1-3) and (1-4). Is preferred.

<Diamine component>
The diamine component for obtaining the specific polymer is a substance containing at least one kind of diamine represented by the above formula (1), may be one kind of diamine, and is composed of two or more kinds of diamines. It may be When a diamine component consists of two or more types of diamine, other diamine may be included with the diamine represented by Formula (1). It is preferable that the ratio of the diamine represented by Formula (1) in the diamine component for obtaining a specific polymer is 10 to 100 mol%, More preferably, it is 30 to 100 mol%, More preferably, it is 50 to 100 mol %.

The diamine used together with the diamine represented by Formula (1) is not particularly limited as a diamine component for obtaining a specific polymer, but for example, a diamine represented by the following Formula (2) and represented by the above Formula (1) And compounds other than.

In the formula (2), Y is a divalent organic group, and more preferably a divalent organic group having 6 to 50 carbon atoms. Here, the organic group is, for example, a divalent hydrocarbon group, a carbon-carbon bond of a divalent hydrocarbon group, -O-, -COO-, -COS-, -CO-, -CONR ^a- , A hetero atom-containing group such as -S-, -NR ^a- , -SO _2- , -Si (R ⁸ ) ₂ -or the like (provided that R ^a is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ⁸ Is a monovalent hydrocarbon group having 1 to 12 carbon atoms)) or a divalent group having a heterocycle. In each of these groups, at least one of the hydrogen atoms bonded to a carbon atom may be substituted by a substituent. Examples of the substituent include halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), a hydroxyl group, a nitro group, an amino group, a carboxyl group, a thiol group, -Si ^(R _{9) 3} (provided that, ^{R 9} Is a C 1-10 alkyl group or an alkoxy group, and a plurality of R ₉ may be the same or different), an alkoxy group and the like.

Here, the term "hydrocarbon group" is meant to include a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. "Chain chain hydrocarbon group" means a hydrocarbon group composed of only a chain structure, which does not contain a cyclic structure in the main chain. However, the chain structure may be linear or branched, and may be saturated or unsaturated. The "alicyclic hydrocarbon group" means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not including an aromatic ring structure. However, it does not need to be comprised only with the structure of alicyclic hydrocarbon, and the thing which has chain structure in the part is also included. The "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a chain structure or a structure of alicyclic hydrocarbon may be included in part thereof.

Examples of the “heterocycle” include aliphatic heterocycles such as piperidine ring, piperazine ring, pyrrolidine ring, azetidine ring, oxetane ring and aziridine ring, pyrrole ring, furan ring, thiophene ring, thiophene ring, imidazole ring, pyrazole ring, oxazole ring, iso 5-membered aromatic heterocycles such as oxazole ring, thiazole ring and isothiazole ring, 6-membered aromatic heterocycles such as pyridine ring, pyrimidine ring, pyridazine ring and pyrazine ring, polycyclic rings such as indole ring and benzimidazole ring Aromatic heterocycles and the like can be mentioned.

A preferred example of Y is preferably a divalent group containing one or more phenylene structures, and more preferably a divalent organic group selected from the following formulas (Y-1) to (Y-3). R ⁵ and R ⁶ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and a hydrogen atom or a methyl group is more preferable.

(Wherein, A ₁ and A ₄ are each independently a single bond, —O—, —CO—, —CO—O—, —OCO—, —NR— (R is a hydrogen atom, a methyl group, tert- Butoxycarbonyl group), -NRCO- (R represents a hydrogen atom or a methyl group), -NRCOO- (R represents a hydrogen atom or a methyl group), -CONR- (R represents a hydrogen atom or methyl) Group), -COS-, -NR ₁ -CO-NR _2- (R ₁ and R ₂ each independently represent a hydrogen atom or a methyl group), -CH ₂ -,-(CH ₂ ) _n - (n is an integer of 2-20), or the -. _(CH _{2) n} - any CH ₂ is, -O -, - CO -, - CO-O -, - NRCO- ( R represents a hydrogen atom or a methyl group), -NRCOO- (R represents a hydrogen atom or a methyl group) , -CONR- (R represents a hydrogen atom or a methyl group), -COS-, -NQ ₁ -CO-NQ _2- (Q ₁ and Q ₂ each independently represent a hydrogen atom or a methyl group. And —NR— (R represents a hydrogen atom, a methyl group or a tert-butoxycarbonyl group), a group substituted with a group selected from pyrrolidine, piperidine and piperazine A ₂ represents a halogen atom or a hydroxyl group , A primary amino group, a thiol group, a nitro group, a phosphoric acid group, or a monovalent organic group having 1 to 10 carbon atoms A ₃ is a definition as given for A ₁ or A ₄ other than a single bond And a plurality of A ₃ may be the same or different, a is an integer of 0 to 4, and when a is 2 or more, the structures of A ₂ may be the same or different, b and c are Each of them is independently an integer of 1 to 2. d is Or it is one of the integer.

The monovalent organic group having 1 to 10 carbon atoms in A ₂ is, for example, an alkyl group having 1 to 3 carbon atoms such as a methyl group, a part or all of hydrogen atoms of the alkyl group having 1 to 3 carbon atoms. Examples thereof include a group substituted with a halogen atom such as a fluorine atom and a chlorine atom, a group having —NHD, and a group having —N (D) ₂ . Here, D represents a carbamate-based protecting group, and examples of the carbamate-based protecting group include a tert-butoxycarbonyl group or 9-fluorenylmethoxycarbonyl group.

As the “group having —NHD”, —NHD, —L— (CH ₂ ) _n —NHD (L represents a single bond, —O—, —COO— or —NHCO—. N is an integer of 1 to 5 And the like.

As the “group having —N (D) ₂ ”, —N (D) ₂ , —L— (CH ₂ ) _n —N (D) ₂ (L is a single bond, —O—, —COO—, — And n represents an integer of 1 to 5.).

Although the structure of Y which is particularly preferable is shown below, the present invention is not limited thereto.

<Tetracarboxylic acid dianhydride component>
As a tetracarboxylic acid dianhydride component for obtaining a specific polymer, the compound represented by following formula (3) is mentioned. The tetracarboxylic acid dianhydride component for obtaining a specific polymer may consist of one type of compound or may consist of two or more types of compounds.

In the formula (3), A is a tetravalent organic group, preferably a tetravalent organic group having 4 to 30 carbon atoms.
Here, the organic group means a group in which two hydrogen atoms are further removed from the above-described divalent organic group. Preferably, a tetravalent organic group having at least one selected from the group consisting of a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cyclohexene ring, a benzene ring and a heterocyclic ring or a 1,2,3,4-butanetetracarboxylic acid dibasic It is a tetravalent organic group derived from an anhydride.

Although the structure of preferable A is shown below, this invention is not limited to these.

Among the above structures, (A-1) and (A-2) are preferable from the viewpoint of further improvement of photoalignment, and (A-4) is preferable from the viewpoint of further improvement of the relaxation rate of accumulated charge, (A-15) to (A-17) are preferable from the viewpoint of further improving the liquid crystal alignment property and the relaxation rate of the accumulated charge.

<Specific polymer>
The specific polymer contained in the liquid crystal aligning agent of the present invention is a polyamic acid obtained by using a diamine component containing a diamine represented by the above formula (1) and a tetracarboxylic acid dianhydride component, and an imidized product thereof. It is a polymer of choice.

In the present invention, the method for obtaining the polyamic acid from the diamine component and the tetracarboxylic acid dianhydride component is not particularly limited, and one example is as follows.
The diamine component and the tetracarboxylic acid dianhydride component are mixed in the presence of an organic solvent and stirred at -20 to 150 ° C, preferably 0 to 70 ° C, for 30 minutes to 24 hours, preferably 1 to 12 hours. Let it react. At this time, an end capping agent such as monoamine or dicarboxylic acid anhydride may be added for the purpose of adjusting the molecular weight of the polymer.
The organic solvent used for the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, γ-butyrolactone, etc. in view of the solubility of monomers and polymers, and one or more of these may be mixed You may use it.
The concentration of the reaction solution is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass, from the viewpoint that precipitation of a polymer hardly occurs and a polymer can be easily obtained.

The imidized polyamic acid in the present invention is a polymer obtained by imidizing the polyamic acid obtained as described above.
The imidization of polyamic acid is convenient to chemical imidization in which a catalyst is added to a solution of polyamic acid. Chemical imidization is preferable because the imidization reaction proceeds at a relatively low temperature, and molecular weight reduction of the polymer does not easily occur in the imidization process. One example of chemical imidization is as follows.
The polyamic acid to be imidized and the basic catalyst are mixed in the presence of an acid anhydride and an organic solvent, and stirred at −20 to 140 ° C., preferably 0 to 100 ° C., for 1 to 100 hours.

As an organic solvent which can be used here, the solvent used for the polymerization reaction of the polyamic acid mentioned above can be used. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine and trioctylamine. Among them, pyridine is preferable because it has a suitable basicity to allow the reaction to proceed. As the acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride and the like can be mentioned. Among them, acetic anhydride is preferable because it facilitates purification after completion of the reaction.
The amount of basic catalyst is 0.5 to 30 times mol, preferably 2 to 20 times mol of the amic acid structure of the polyamic acid, and the amount of acid anhydride is 1 to 50 times mol of the amic acid structure, preferably It is 3 to 30 times mol. The imidation ratio of the resulting polymer can be controlled by adjusting the amount of catalyst, temperature and reaction time.

The polyamic acid and its imidized product obtained as described above can be recovered by precipitating a polymer by pouring the reaction solution into a poor solvent while well stirring it. In particular, when the polyamic acid is chemically imidized, since the catalyst and the like remain in the reaction liquid, it is preferable to use the liquid crystal aligning agent of the present invention after recovering and purifying the polymer.
The purification of the polymer can be carried out by washing the polymer precipitated above with a poor solvent and then drying at room temperature or by heating. The poor solvent used for polymer precipitation and washing is not particularly limited, but water, methanol, ethanol, 2-propanol, hexane, butyl cellosolve, acetone, toluene and the like can be mentioned, with preference given to water, methanol, ethanol, 2-propanol and the like .

<Liquid crystal alignment agent>
The liquid crystal aligning agent of this invention is a composition containing said specific polymer and an organic solvent, and may contain 2 or more types of specific polymers of a different structure. In addition, the liquid crystal aligning agent of the present invention may contain a polymer other than the specific polymer (hereinafter, also referred to as a second polymer) and various additives as long as the effects described in the present invention can be exhibited. Good.

When the liquid crystal aligning agent of the present invention contains the second polymer, the ratio of the specific polymer to the total polymer components is preferably 5% by mass or more, and an example thereof is 5 to 95% by mass.
The second polymer includes polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene or derivative thereof, poly (styrene-phenylmaleimide) derivative, poly (meth) An acrylate etc. can be mentioned.

In particular, a polyamic acid (hereinafter also referred to as a second polyamic acid) obtained from a tetracarboxylic acid dianhydride component and a diamine component not containing a diamine represented by the above formula (1) is preferable as the second polymer .

Examples of the tetracarboxylic acid dianhydride component for obtaining the second polyamic acid include the compounds represented by the above formula (3), and a structure preferable as A in the formula (3) and the reason therefor are also the above specific Same as described for the polymer. The tetracarboxylic acid dianhydride component for obtaining the second polyamic acid may be one kind of tetracarboxylic acid dianhydride, or two or more kinds of tetracarboxylic acid dianhydrides may be used in combination. .

As a diamine component for obtaining a 2nd polyamic acid, the compound represented by said Formula (2) and the compound except the diamine represented by said Formula (1) can be mentioned. The diamine component for obtaining the second polyamic acid may be one kind of diamine, or two or more kinds of diamines may be used in combination.

Although the structure of Y of Formula (2) preferable when using as a diamine component for obtaining a 2nd polyamic acid below is shown, this invention is not limited to these.

The molecular weight of the polymer contained in the liquid crystal aligning agent of the present invention is not particularly limited as long as a uniform and defect-free coating film can be formed on the substrate. If it dares to cite an example, it is 2,000 to 500,000, preferably 5,000 to 300,000, more preferably 10,000 to 100,000 in weight average molecular weight. In addition, the number average molecular weight is 1,000 to 250,000, preferably 2,500 to 150,000, more preferably 5,000 to 50,000.
The concentration of the polymer in the liquid crystal aligning agent of the present invention can be appropriately changed by setting the thickness of the coating film to be formed, but from the point of forming a uniform, defect-free coating film, 1% by mass or more It is preferable that it is 10 mass% or less from the point of the storage stability of a solution. The particularly preferred concentration of the polymer is 2 to 8% by mass.

The organic solvent contained in the liquid crystal aligning agent of this invention will not be specifically limited if a polymer component melt | dissolves uniformly.
Specific examples thereof include N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, Examples include 2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide and the like. These may be used alone or in combination of two or more. Moreover, even if it is a solvent which can not melt | dissolve a polymer component uniformly by itself, as long as a polymer does not precipitate, you may mix with said organic solvent.

Moreover, the organic solvent contained in a liquid crystal aligning agent uses the mixed solvent which used together the solvent which improves the surface smoothness of the coating property at the time of applying a liquid crystal aligning agent in addition to the above solvents and a liquid crystal aligning agent. In general, such a mixed solvent is suitably used also in the liquid crystal aligning agent of the present invention. Although the specific example of the organic solvent to be used together is given to the following, it is not limited to these examples.

For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 2,6- Dimethi -4-Heptanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3 -Butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, diisopropyl ether, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol Dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl Ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 2,6-dimethyl-4-heptanone, 4,6-dimethyl-2-heptanone, 3-ethoxy Butyl acetate, 1-methyl pentyl acetate, 2-ethyl butyl acetate, 2-ethyl hexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2- (methoxymethoxy) ethanol, Ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2- (hexyloxy) ethanol, furfuryl alcohol, diethylene glycol, Propylene glycol, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, propylene glycol monobutyl ether, 1- (butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol Propylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether Luacetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, Ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl ethyl 3-ethoxypropionate, 3-methoxypropionic acid Ethyl, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, lactic acid methyl ester, Acid ethyl ester, lactic acid n- propyl ester, lactate n- butyl ester, lactic acid isoamyl ester, and the like solvents represented by the following formula [D-1] ~ [D-3].

In Formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms, and in Formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms, Formula [D-3] among, ^{D 3} is an alkyl group having 1 to 4 carbon atoms.

Among the preferred solvent combinations, N-methyl-2-pyrrolidone, γ-butyrolactone, ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone And propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether And 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrole Ridone, γ-butyrolactone, propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol, N-methyl-2-pyrrolidone, γ-butyrolactone and dipropylene glycol dimethyl ether can be mentioned. The type and content of such a solvent are appropriately selected according to the coating device, coating conditions, coating environment and the like of the liquid crystal alignment agent.

The liquid crystal aligning agent of the present invention is, besides the above, a dielectric or a conductive substance for the purpose of changing electric properties such as dielectric constant and conductivity of the liquid crystal alignment film, as long as the effects of the present invention are not impaired. Silane coupling agent for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate, a crosslinkable compound for the purpose of enhancing the hardness and density of the film when forming the liquid crystal alignment film, and polyamics when firing the coating An imidization accelerator for the purpose of efficiently advancing imidization of an acid may be added.

Although the example of a crosslinking | crosslinked compound is shown below, this invention is not limited to these.

The crosslinkable compound is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. If the amount is less than 0.1 part by mass, no effect can be expected. If the amount is more than 30 parts by mass, the orientation of the liquid crystal is reduced.

<Liquid crystal alignment film>
The liquid crystal aligning film of this invention is obtained from said liquid crystal aligning agent, and the existing method can be used for the method of producing a liquid crystal aligning film. Typical examples include a coating process, a drying process, a baking process, and an alignment treatment process. Here, the orientation treatment step may be before the firing step, simultaneously with the firing step, or after the firing step.

As a coating method of a liquid crystal aligning agent, a spin coat method, a printing method, an inkjet method etc. are mentioned. Examples of the substrate to which the liquid crystal aligning agent is applied include plastic substrates such as a glass substrate, a silicon nitride substrate, an acrylic substrate, and a polycarbonate substrate. When using for a liquid crystal display element etc., it is preferable to use the board | substrate with which the ITO electrode etc. for liquid crystal drive were formed from the point of the simplification of a process.

The drying step after the application of the liquid crystal aligning agent can be performed at any temperature and time. Usually, the reaction is carried out at 50 ° C. to 120 ° C. for 1 minute to 10 minutes in order to sufficiently remove the contained organic solvent.
The baking process of the liquid crystal aligning agent is performed, for example, at 150 ° C. to 300 ° C. for 5 minutes to 120 minutes. When the polymer contained in the liquid crystal aligning agent has an amic acid structure, thermal imidization occurs in this firing step, and the polyamic acid changes to a polyimide. The thickness of the coating after firing is not particularly limited, and is, for example, 5 to 300 nm, preferably 10 to 200 nm, and more preferably 50 nm to 150 nm.

As an orientation treatment process, a rubbing method, an optical orientation method, etc. are mentioned.
The rubbing method can be performed using an existing rubbing apparatus. Cotton, nylon, rayon etc. are mentioned as a material of the rubbing cloth in this case. As the conditions for the rubbing treatment, generally, conditions of a rotational speed of 300 to 2000 rpm, a feed speed of 5 to 100 mm / s, and a pressing amount of 0.1 to 1.0 mm are used. Thereafter, ultrasonic cleaning is performed using pure water, alcohol or the like to remove the residue generated by rubbing.

A specific example of the light alignment method is a method of irradiating the surface of the coated film with polarized radiation. As radiation, ultraviolet light and visible light having a wavelength of 100 nm to 800 nm can be used. Among these, ultraviolet light having a wavelength of 100 nm to 400 nm is preferable, and one having a wavelength of 200 nm to 400 nm is particularly preferable. The dose of radiation is preferably 1 ~ 10,000mJ / cm ^2, particularly preferably 100 ~ 5,000mJ / cm ^2. The higher the extinction ratio of polarized ultraviolet light, the higher the anisotropy that can be imparted. Specifically, the extinction ratio of the linearly polarized ultraviolet light is preferably 10: 1 or more, more preferably 20: 1 or more.

The photoaligned film may be washed with a solvent containing at least one selected from water and an organic solvent. It will not specifically limit, if it is a solvent which melt | dissolves the decomposition product etc. which were produced | generated by light irradiation as a solvent used for a washing process. As specific examples, 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, 3- And methyl methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate and the like. Two or more of these solvents may be used in combination. From the viewpoint of versatility and safety, at least one selected from the group consisting of water, 2-propanol, 1-methoxy-2-propanol and ethyl lactate is more preferable. Water, 2-propane and a mixed solvent of water and 2-propanol are particularly preferred. After the washing treatment, for the purpose of removing the organic solvent in the solution used, either rinsing with a low boiling point solvent such as water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone or drying, or both You may

The film subjected to the orientation treatment as described above may be heat-treated at 150 ° C. or more for the purpose of increasing the anisotropy of the film. An increase in the anisotropy of the film is achieved by the reorientation of molecular chains by heat. The heating temperature is preferably 150 to 300.degree. The higher the temperature, the more the reorientation of the molecular chain is promoted, but it is preferable to keep the temperature at which the molecular chain does not decompose, for example, 180 to 250 ° C. is more preferable, and 200 to 230 ° C. is particularly preferable. The heating time is, for example, 5 minutes to 120 minutes.
In the method of producing a liquid crystal alignment film, when the alignment treatment step is carried out before the firing step, the above-mentioned firing step can also serve as a heating step for the purpose of increasing the anisotropy of the above-mentioned film.

The liquid crystal alignment film of the present invention is suitable as a liquid crystal alignment film of a liquid crystal display element of a lateral electric field type such as IPS type or FFS type, and particularly useful as a liquid crystal alignment film of a liquid crystal display element of FFS type.

<Liquid crystal display element>
The liquid crystal display element of this invention has a liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention, The form and manufacturing method are not specifically limited. For example, after a substrate with a liquid crystal alignment film is obtained by the method for producing a liquid crystal alignment film, a liquid crystal cell is produced by a known method and used to make a liquid crystal display element.

Although an example of a method for manufacturing a liquid crystal cell is shown below, the present invention is not limited thereto.
First, a set of glass substrates provided with electrodes for driving liquid crystal is prepared, and the liquid crystal alignment film of the present invention is formed on the substrates by the above method.
Next, bead spacers are dispersed on the alignment film surface of one of the substrates, and a seal material is printed. At this time, the bead spacer may be mixed in the sealing material, and instead of using the bead spacer, a substrate on which a columnar spacer is formed in advance may be used.
Finally, the liquid crystal alignment film surface is made to face the above-mentioned substrate and the other substrate, and the liquid crystal composition is sealed in the space surrounded by the two substrates and the sealing material to form a liquid crystal cell. The liquid crystal composition may be enclosed by a vacuum injection method or a liquid crystal dropping method (ODF).
The liquid crystal display element of the present invention can be obtained by using the liquid crystal cell manufactured by the above steps.

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples and the like, but the present invention is not limited to these examples.

In addition, the symbol of a compound and a solvent is as follows.
DA-1: Compound DA-2 represented by the following structural formula (DA-1): compound DA-3 represented by the following structural formula (DA-2): represented by the following structural formula (DA-3) Compound DA-4: Compound DA-5 represented by the following structural formula (DA-4): Compound DA-6 represented by the following structural formula (DA-5): represented by the following structural formula (DA-6) Compound DA-7: Compound DA-8 represented by the following structural formula (DA-7): Compound DA-9 represented by the following structural formula (DA-8): Table represented by the following structural formula (DA-9) Compound DA-10: Compound DA-11 represented by the following Structural Formula (DA-10): Compound CA-1 represented by the following Structural Formula (DA-11): By the following Structural Formula (CA-1) Compound CA-2 represented: Compound CA-3 represented by the following structural formula (CA-2): By the following structural formula (CA-3) Compound

DA-1 to DA-5 are novel compounds which have not been published in the literature or the like, and their synthesis methods will be described in detail in the following synthesis examples 1 to 9.

Abbreviations of organic solvents used in Examples and the like are as follows.
NMP: N-methyl-2-pyrrolidone.
GBL: γ-butyrolactone BCS: butyl cellosolve.
THF: tetrahydrofuran.
DMF: N, N-dimethylformamide.
CH ₂ Cl _2: dichloromethane.
MeOH: methanol.
EtOH: ethanol.
IPA: isopropyl alcohol.

<Measurement of ¹ H NMR>
The ¹ H-NMR of the synthesized compound was measured under the following conditions.
Apparatus: Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) “INOVA-400” (manufactured by Varian) 400 MHz.
Solvent: deuterated chloroform (CDCl ₃ ) or deuterated N, N-dimethyl sulfoxide ([D ₆ ] -DMSO).
Reference material: tetramethylsilane (TMS).

<Measurement of viscosity>
In the synthesis example, the viscosity of the polymer solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), a sample volume of 1.1 mL, corn rotor TE-1 (1 ° 34 ', R24), temperature 25 Measured in ° C.

Synthesis Example 1
Synthesis of [DA-1]:

In a 2 L four-necked flask, 3- (4-tert-butoxycarbonylaminophenyl) propanol (306.9 g, 944 mmol), triethylamine (190.0 g, 1888 mmol), THF (1000 g) are charged, and ethanesulfonyl chloride is added in a water bath. After dropwise addition of (182.0 g, 1416 mmol), the mixture was stirred at room temperature. After completion of the reaction, the reaction system was poured into ethyl acetate (2 L) and extraction was performed using pure water (1 L). Anhydrous magnesium sulfate was added to the extracted organic layer, it was dehydrated and dried, and anhydrous magnesium sulfate was filtered. The solvent of the obtained filtrate was distilled off with a rotary evaporator to obtain 336.7 g of [DA-1-1].

[DA-1-1] (336.7 g, 980 mmol), 4-nitrophenol (150.0 g, 1078 mmol), potassium carbonate (203.0 g, 1470 mmol), and NMP (1700 g) are added to a 3 L four-necked flask, Stir at 80 ° C. After completion of the reaction, the reaction system was poured into ethyl acetate (4 L) and neutralized with 1N aqueous hydrochloric acid solution. The aqueous layer was removed and the organic layer was washed with pure water (2 L). The washed organic layer was dried over anhydrous magnesium sulfate, dried over anhydrous magnesium sulfate, and filtered. The obtained filtrate was subjected to solvent distillation with a rotary evaporator, IPA (2000 g) was added, and repulp washing was performed at room temperature to obtain 173.4 g of [DA-1-2].

[DA-1-2] (86.7 g, 232 mmol), 6 N aqueous hydrochloric acid solution (180 g) and ethyl acetate (700 g) were charged into a 2 L four-necked flask, and the mixture was stirred at 60 ° C. After completion of the reaction, the reaction system was poured into pure water (1 L) and neutralized with 1N aqueous sodium hydroxide solution. The aqueous layer was removed and the organic layer was washed with pure water (2 L). The washed organic layer was dried over anhydrous magnesium sulfate, dried over anhydrous magnesium sulfate, and filtered. The solvent of the obtained filtrate was distilled off with a rotary evaporator to obtain 62.6 g of [DA-1-3].

[DA-1-3] (62.6 g, 230 mmol) and NMP (900 g) were added to a 2 L four-necked flask, and 1,3-DMCBDA (25.5 g, 114 mmol) was added in a water bath, then at room temperature Stir for 6 h. Subsequently, pyridine (54.5 g, 690 mmol) and acetic anhydride (35.2 g, 345 mmol) were added to the reaction solution, and the mixture was stirred at 60 ° C. After completion of the reaction, the reaction system was poured into pure water (4 L), and the precipitate was separated by filtration. MeOH (500 g) was added to the obtained crude product, and repulping was performed at room temperature to obtain 82.0 g of [DA-1-4].

[DA-1-4] (80.0 g, 109 mmol) and DMF (3200 g) were charged into a 5 L four-necked flask, and after replacing with nitrogen, 5 wt% Pd / C (8.0 g) was added, and hydrogen replacement was carried out. Stir at ° C. After completion of the reaction, the reaction solution was filtered through a 0.45 μm membrane filter to remove Pd / C. The obtained filtrate was evaporated using a rotary evaporator, ethyl acetate (1000 g) was added, and repulping was performed at room temperature to obtain 59.1 g of [DA-1] (red-purple solid). The results of ¹ H-NMR of the desired product are shown below. From this result, it was confirmed that the obtained solid was the target [DA-1].

¹ H NMR (400 MHz, [D ₆ ] -DMSO): δ 7.38-7.40 (d, 4 H), 7.31-7. 33 (d, 4 H), 6.65-6. 67 (d, 4 H), 6. 49-6. 51 (d, 4H), 4.60 (d, 4H), 3.83-3.86 (t, 4H), 3.54 (s, 2H), 2.73-2.80 (t, 4H), 1.97-2.01 (t, 4H), 1.39 (s, 6H)

Synthesis Example 2
Synthesis of [DA-2]:

[DA-1-2] (86.7 g, 233 mmol), THF (350 g) and EtOH (90 g) are charged into a 1 L four-necked flask, and after nitrogen substitution, 5 wt% Pd / C (8.7 g) is added. It was replaced with hydrogen and stirred at room temperature. After completion of the reaction, the reaction solution was filtered through a 0.45 μm membrane filter to remove Pd / C. The solvent of the obtained filtrate was distilled off with a rotary evaporator to obtain 65.8 g of [DA-2-1].

[DA-2-1] (65.8 g, 192 mmol) and NMP (700 g) were added to a 2 L four-necked flask, and 1,3-DMCBDA (21.4 g, 96 mmol) was added in a water bath, then at room temperature Stir for 6 h. Subsequently, pyridine (45.6 g, 576 mmol) and acetic anhydride (29.8 g, 292 mol) were added to the reaction solution, and the mixture was stirred at 60 ° C. After completion of the reaction, the reaction system was poured into pure water (3 L), and the precipitate was separated by filtration. MeOH (1000 g) was added to the obtained crude product, and repulping was performed at room temperature to obtain 83.0 g of [DA-2-2].

[DA-2-2] (83.0 g, 96 mmol), 6 N aqueous hydrochloric acid solution (170 g) and ethyl acetate (700 g) were charged into a 2 L four-necked flask, and the mixture was stirred at 60 ° C. After completion of the reaction, the reaction system was poured into pure water (1 L) and neutralized with triethylamine. The precipitate was separated by filtration, ethyl acetate (500 g) was added, and repulping was performed at room temperature to obtain 25.2 g of [DA-2]. The results of ¹ H-NMR of the desired product are shown below. From this result, it was confirmed that the obtained solid was the target [DA-2].

¹ H NMR (400 MHz, [D ₆ ] -DMSO): δ 7.29-7.32 (d, 4 H), 7.05-7.07 (d, 4 H), 6.87-6.89 (d, 4 H), 6.49-6.51 (d, 4H), 4.86 (d, 4H), 3.97-4.00 (t, 4H), 3.52 (s, 2H), 2.56-2.60 (t, 4H), 1.93-1.97 (t, 4H), 1.38 (s, 6H)

Synthesis Example 3
Synthesis of [DA-3]:

A 2 L four-necked flask is charged with N-Boc-2- (4-aminophenyl) ethanol (158.7 g, 669 mmol), triethylamine (135.4 g, 1338 mmol), THF (1100 g), and ethanesulfonyl chloride in a water bath After dropping (128.9 g, 1003 mmol), the mixture was stirred at room temperature. After completion of the reaction, the reaction system was poured into ethyl acetate (3 L) and extraction was performed using pure water (1 L). Anhydrous magnesium sulfate was added to the extracted organic layer, it was dehydrated and dried, and anhydrous magnesium sulfate was filtered. The solvent of the obtained filtrate was distilled off with a rotary evaporator to obtain 224.2 g of [DA-3-1].

[DA-3-1] (217.3 g, 660 mmol), 4-nitrophenol (101.0 g, 726 mmol), potassium carbonate (136.8 g, 990 mmol), NMP (1200 g) are charged into a 3 L four-necked flask, Stir at 80 ° C. After completion of the reaction, the reaction system was poured into ethyl acetate (2 L) and neutralized with 1N aqueous hydrochloric acid solution. The aqueous layer was removed and the organic layer was washed with pure water (2 L). The washed organic layer was dried over anhydrous magnesium sulfate, dried over anhydrous magnesium sulfate, and filtered. The obtained filtrate was evaporated using a rotary evaporator, IPA (400 g) was added, and repulping was performed at room temperature to obtain 164.8 g of [DA-3-2].

[DA-3-2] (84.3 g, 226 mmol), 6 N aqueous hydrochloric acid solution (200 g) and ethyl acetate (600 g) were charged into a 2 L four-necked flask, and the mixture was stirred at 60 ° C. After completion of the reaction, the reaction system was poured into pure water (1.2 L) and neutralized with 1N aqueous sodium hydroxide solution. The aqueous layer was removed and the organic layer was washed with pure water (2 L). The washed organic layer was dried over anhydrous magnesium sulfate, dried over anhydrous magnesium sulfate, and filtered. The solvent of the obtained filtrate was distilled off with a rotary evaporator to obtain 60.8 g of [DA-3-3].

In a 2 L four-necked flask, charge [DA-3-3] (60.8 g, 235 mmol) and NMP (600 g), and after adding 1,3-DMCBDA (24.8 g, 111 mmol) in a water bath, at room temperature Stir for 6 h. Subsequently, pyridine (55.8 g, 705 mmol) and acetic anhydride (35.9 g, 352 mmol) were added to the reaction solution, and the mixture was stirred at 60 ° C. After completion of the reaction, the reaction system was poured into pure water (3 L), and the precipitate was separated by filtration. EtOH (1000 g) was added to the obtained crude product, and repulped at room temperature to obtain 79.1 g of [DA-3-4].

Charge [DA-3-4] (79.0 g, 112 mmol) and DMF (800 g) to a 3 L four-necked flask, replace with nitrogen, add 5 wt% Pd / C (7.9 g), replace with hydrogen, and change to room temperature. Stir. After completion of the reaction, the reaction solution was filtered through a 0.45 μm membrane filter to remove Pd / C. The obtained filtrate was evaporated using a rotary evaporator, ethyl acetate (1500 g) was added, and repulping was performed at room temperature to obtain 69.9 g of [DA-3] (white solid). The results of ¹ H-NMR of the desired product are shown below. From this result, it was confirmed that the obtained solid was the target [DA-3].

¹ H NMR (400 MHz, [D ₆ ] -DMSO): δ 7.46-7.48 (d, 4 H), 7.33-7. 35 (d, 4 H), 6.65-6. 68 (d, 4 H), 6. 49-6. 51 (d, 4H), 4.61 (s, 4H), 4.07-4.10 (t, 4H), 3.54 (s, 2H), 3.02-3.05 (t, 4H), 1. 39 (s, 6H)

Synthesis Example 4
Synthesis of [DA-4]:

[DA-3-2] (80.6 g, 216 mmol), THF (300 g), EtOH (100 g) are charged into a 1 L four-necked flask, and 5 wt% Pd / C (8.0 g) is added after nitrogen substitution, It was replaced with hydrogen and stirred at room temperature. After completion of the reaction, the reaction solution was filtered through a 0.45 μm membrane filter to remove Pd / C. The solvent of the obtained filtrate was distilled off with a rotary evaporator to obtain 73.9 g of [DA-4-1].

[DA-4-1] (73.9 g, 225 mmol) and NMP (700 g) were added to a 2 L four-necked flask, and 1,3-DMCBDA (23.7 g, 106 mmol) was added in a water bath, then at room temperature Stir for 6 h. Subsequently, pyridine (53.4 g, 675 mmol) and acetic anhydride (34.5 g, 338 mol) were added to the reaction solution, and the mixture was stirred at 60 ° C. After completion of the reaction, the reaction system was poured into pure water (3 L), and the precipitate was separated by filtration. EtOH (1000 g) was added to the obtained crude product, and repulping was performed at room temperature to obtain 85.4 g of [DA-4-2].

[DA-4-2] (85.4 g, 101 mmol), 6 N aqueous hydrochloric acid solution (200 g), and ethyl acetate (800 g) were charged into a 2 L four-necked flask, and the mixture was stirred at 50 ° C. After completion of the reaction, the reaction system was poured into pure water (1.2 L) and neutralized with triethylamine. The precipitate was separated by filtration, ethyl acetate (1500 g) was added, and repulping was performed at room temperature to obtain 61.1 g of [DA-4]. The results of ¹ H-NMR of the desired product are shown below. From this result, it was confirmed that the obtained solid was the target [DA-4].

¹ H NMR (400 MHz, [D ₆ ] -DMSO): δ 7.29-7.31 (d, 4 H), 7.05-7.08 (d, 4 H), 6.97-6.99 (d, 4 H), 6.51-6.53 (d, 4H), 4.90 (s, 4H), 4.11-4.14 (t, 4H), 3.51 (s, 2H), 2.86-2.89 (t, 4H), 1.37 (s, 6H)

Synthesis Example 5
Synthesis of [DA-5]:

In a 3 L four-necked flask, 4- [6- (4-aminophenoxy) hexyloxy] aniline (90.0 g, 300 mmol) and THF (600 g) are charged, and di-tert-butyl dicarbonate (65. After dropping 4 g (300 mmol), the mixture was stirred at room temperature. After completion of the reaction, the reaction solution is concentrated, and the obtained residue is isolated by silica gel column chromatography (ethyl acetate: hexane = 1: 1 volume ratio) to obtain 48.0 g of [DA-5-1]. Obtained.

[DA-5-1] (48.0 g, 120 mmol) and NMP (480 g) were added to a 3 L four-necked flask, and after adding 1,3-DMCBDA (13.4 g, 60 mmol) in a water bath, at room temperature Stir for 6 h. Subsequently, pyridine (28.4 g, 360 mmol) and acetic anhydride (18.4 g, 180 mmol) were added to the reaction solution, and the mixture was stirred at 60 ° C. After completion of the reaction, the reaction system was poured into pure water (3 L), and the precipitate was separated by filtration. MeOH (400 ml) was added to the obtained crude product, and repulping was performed at room temperature to obtain 42.5 g of [DA-5-2].

[DA-5-2] (42.5 g, 43 mmol) and CH ₂ Cl ₂ (640 g) were charged in a 3 L four-necked flask, and trifluoroacetic acid (43.9 g, 430 mmol) was added dropwise in a water bath, and then room temperature Stir. After completion of the reaction, the reaction solution was concentrated, pure water (2 L) was added to the obtained crude product, and the reaction mixture was neutralized with triethylamine. The precipitate was filtered, MeOH (100 g) was added to the obtained crude product, and repulped at room temperature to obtain 26.3 g of [DA-5] (purple solid). The results of ¹ H-NMR of the desired product are shown below. From this result, it was confirmed that the obtained solid was the target [DA-3].

¹ H NMR (400 MHz, [D ₆ ] -DMSO): δ 7.29-7.31 (d, 4 H), 7.06-7.08 (d, 4 H), 6.63-6.65 (d, 4 H), 6.48-6.50 (d, 4H), 4.59 (s, 4H), 4.01-4.04 (t, 4H), 3.80-3.84 (t, 4H), 3.52 (s, 2H), 1.74-1.76 (t, 4H), 1.66-1.70 (t, 4H), 1.46-1.48 (m, 8H), 1.38 (s, 6H)

Synthesis Example 7
2.83 g (4.20 mmol) of DA-1, 0.763 g (2.80 mmol) of DA-7 are added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and 25.0 g of NMP is added The mixture was stirred and dispersed while feeding nitrogen. While stirring this diamine solution under water cooling, 1.28 g (6.51 mmol) of CA-1 is added, 10.7 g of NMP is further added, and stirring is performed under a nitrogen atmosphere at 23 ° C. for 8 hours to contain an imide group A solution of polyamic acid (a-1) was obtained. The viscosity of this solution at a temperature of 25 ° C. was 945 mPa · s.

Synthesis Examples 8 to 15
Polyamic acids (a-2) to (a-5) and (c-1) can be prepared by using tetracarboxylic acid components, diamine components, and NMP as shown in the following table and carrying out them in the same manner as in Synthesis Example 7, respectively. And solutions of (b-1) to (b-3) were obtained.

Example 1
6.25 g of the solution of polyamic acid (a-1) obtained in Synthesis Example 7 is taken in a 100 ml Erlenmeyer flask, 0.50 g of NMP, 4.50 g of GBL and 3.75 g of BCS are added, and it is 3 hours at room temperature Stir to obtain a liquid crystal aligning agent (1). No abnormality such as turbidity or precipitation was observed in this liquid crystal aligning agent, and it was confirmed that the solution was a uniform solution.

Examples 2 to 5, Comparative Example 1
A liquid crystal aligning agent shown in the following Table by carrying out in the same manner as in Example 1 except that the solution of polyamic acid obtained in Synthesis Example 8 to 12 is used instead of the solution of polyamic acid (a-1) (2) to (5) and (9) were obtained. No abnormality such as turbidity or precipitation was observed in this liquid crystal aligning agent, and it was confirmed that the solution was a uniform solution.

Example 6
In a 100 ml conical flask, 2.50 g of the solution of polyamic acid (a-2) obtained in Synthesis Example 8 and 3.00 g of the solution of polyamic acid (b-1) obtained in Synthesis Example 13 are added to NMP 1 .25g, 4.50g of GBL, and 3.75g of BCS were added, and it stirred at room temperature for 3 hours, and obtained the liquid crystal aligning agent (6). No abnormality such as turbidity or precipitation was observed in this liquid crystal aligning agent, and it was confirmed that the solution was a uniform solution.

Examples 7 to 8
The liquid crystal aligning agent shown in the following table is carried out in the same manner as in Example 6, except that the solution of polyamic acid obtained in Synthesis Example 14 to 15 is used instead of the solution of polyamic acid (b-1). (7) to (8) were obtained. No abnormality such as turbidity or precipitation was observed in this liquid crystal aligning agent, and it was confirmed that the solution was a uniform solution.

Examples 9 to 16 and Comparative Example 2
A liquid crystal cell was produced in the following procedure using the liquid crystal aligning agent obtained above, and the voltage retention was measured.

[Fabrication of liquid crystal cell for evaluation of voltage holding ratio]
The liquid crystal aligning agent was filtered through a 1.0 μm filter, spin-coated on a glass substrate with an ITO electrode, and dried on a hot plate at 80 ° C. for 2 minutes. Next, a predetermined amount of UV light with a wavelength of 254 nm linearly polarized with an extinction ratio of 26: 1 is irradiated to the coated film surface through a polarizing plate, and baking is performed in a hot air circulating oven at 230 ° C. for 30 minutes. Obtained. Two substrates obtained with the liquid crystal alignment film thus obtained are combined into one set, and a bead spacer having a diameter of 4 μm is dispersed on the alignment film surface of one of the substrates, and a sealing material is printed. After bonding so that the liquid crystal alignment film faces face each other and the alignment directions of the liquid crystals coincide with each other, the sealing material is cured to produce an empty cell. A liquid crystal MLC-3019 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 110 ° C. for 1 hour, allowed to stand overnight, and then used for measurement of voltage retention.
In addition, the irradiation amount of polarized ultraviolet light in the liquid crystal cell manufacturing process is irradiated in advance in the range of 0.1 to 1.0 J / cm ² for each liquid crystal aligning agent used to manufacture a liquid crystal cell, and the alignment property of liquid crystal Adopted the best dose.
The liquid crystal cell had no defect in the alignment of the liquid crystal, and the liquid crystal alignment state was good.

[Measurement of voltage holding ratio]
An AC voltage of 1 V was applied for 60 μs at a temperature of 60 ° C. to the above liquid crystal cell, the voltage after 500 ms was measured, and how much the voltage could be held was calculated as a voltage holding ratio (VHR). . In addition, the measurement was performed using a voltage holding ratio measuring apparatus (VHR-1, manufactured by Toyo Technica Co., Ltd.) at a voltage of ± 1 V, a pulse width of 60 μs, and a flame period of 500 ms. . Thereafter, the liquid crystal cell was left for 120 hours on the LED back light panel which had been lit at a temperature of 23 ° C., and then the voltage retention was measured again with the same setting as described above.

Below, the measurement result of the irradiation amount of the polarization | polarized-light ultraviolet light at the time of liquid crystal cell preparation, and a voltage retention rate is shown.

From the above results, it is found that the liquid crystal cell using the liquid crystal aligning agent of the present invention has better voltage holding ratio than the liquid crystal cell using the liquid crystal aligning agent of the comparative example in both the initial value and after leaving the backlight. Was confirmed.
Further, in the diamine represented by the formula (1), liquid crystal aligning agents (1) to (4) containing a polymer using a diamine in which at least one of n1 and n2 in each of L1 and L2 is 0, and (6) to (8) are compared with the liquid crystal aligning agent (5) containing a polymer using a diamine in which n1 and n2 are both 1 in L1 and L2 respectively, and the voltage holding ratio by the backlight left standing It was confirmed that the decrease in

Examples 17 to 24
An FFS-driven liquid crystal cell was produced according to the following procedure using the liquid crystal aligning agent obtained above, and residual image characteristics were confirmed.

[Configuration of FFS Drive Liquid Crystal Cell]
The liquid crystal cell for the Fringe Field Switching (FFS) mode has the FOP (Finger on Plate) electrode layer consisting of a plane-shaped common electrode-insulation layer-comb-shaped pixel electrode formed on the surface. A glass substrate of No. 1 and a second glass substrate having a columnar spacer with a height of 4 μm on the front surface and an ITO film for charging prevention formed on the back surface are one set. The pixel electrode has a comb-tooth shape in which a plurality of electrode elements each having a width of 3 μm whose central portion is bent at an internal angle of 160 ° are arranged in parallel with an interval of 6 μm. It has a first region and a second region bordering on a line connecting the bent portions of the plurality of electrode elements.
The liquid crystal alignment film formed on the first glass substrate is subjected to alignment processing so that the alignment direction of the liquid crystal is orthogonal to the direction equally dividing the inner angle of the bent pixel, and the liquid crystal alignment film formed on the second glass substrate is The alignment treatment is performed so that the alignment direction of the liquid crystal on the first substrate and the alignment direction of the liquid crystal on the second substrate coincide with each other when the liquid crystal cell is manufactured.

[Production of liquid crystal cell]
A liquid crystal aligning agent filtered with a 1.0 μm filter was applied by spin coating on the surface of each of the above-mentioned pair of glass substrates, and dried for 2 minutes on a hot plate at 80 ° C. Thereafter, a predetermined amount of UV light with a wavelength of 254 nm linearly polarized with an extinction ratio of 26: 1 is irradiated to the coated film surface through a polarizing plate, and then baked for 30 minutes in a hot air circulating oven at 230 ° C. A substrate with an alignment film was obtained.
Next, a sealing material was printed on one of the pair of glass substrates with a liquid crystal alignment film, the other substrate was bonded so that the liquid crystal alignment film faces face one another, and the sealing material was cured to produce an empty cell.
A liquid crystal MLC-3019 (manufactured by Merck & Co., Inc.) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 110 ° C. for 1 hour, allowed to stand overnight, and evaluated for residual image characteristics.
The liquid crystal cell had no defect in the alignment of the liquid crystal, and the liquid crystal alignment state was good.

[Evaluation of afterimage characteristics by long-term alternating current drive]
An alternating voltage of ± 5 V at a frequency of 60 Hz was applied for 120 hours to the FFS-driven liquid crystal cell prepared above under a constant temperature environment of 60 ° C. Thereafter, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited, and left at room temperature for a day.
With respect to the liquid crystal cell subjected to the above processing, the difference between the alignment direction of the liquid crystal in the first region of the pixel and the alignment direction of the liquid crystal in the second region in the no voltage applied state was calculated as an angle.
Specifically, a liquid crystal cell is placed between two polarizing plates disposed so that the polarization axes are orthogonal, and the backlight is turned on, so that the transmitted light intensity in the first region of the pixel is minimized. Adjust the placement angle of. Next, the rotation angle required when rotating the liquid crystal cell is determined so as to minimize the transmitted light intensity in the second region of the pixel.
It can be said that the afterimage characteristic by long-term alternating current drive is better as the value of the rotation angle is smaller.

Below, the irradiation amount of the polarized ultraviolet at the time of liquid crystal cell preparation, and the evaluation result of an afterimage characteristic are shown.

From the above results, in the diamine represented by the formula (1), liquid crystal aligning agents (1), (2) containing a polymer using a diamine in which the value of n1 + n2 + m in each of L1 and L2 is an even number, and (5) to (8) have good voltage retention of the liquid crystal cell and good residual image characteristics even with a liquid crystal alignment film manufactured by a process of irradiating with light and then baking. confirmed.

The liquid crystal aligning agent of this invention can manufacture a liquid crystal aligning film by the photo-alignment method. The liquid crystal display element manufactured using the liquid crystal aligning agent of this invention is excellent in productivity and reliability, and can be suitably utilized for a large screen and a high definition liquid crystal television etc. In addition, the liquid crystal alignment film of the present invention is excellent in reliability, and can also be used for a variable phase shifter using liquid crystal, and this variable phase shifter is suitable, for example, for an antenna or the like capable of varying the resonance frequency. Available.

Claims

A polymer selected from a polyamic acid obtained from a tetracarboxylic acid dianhydride component and a diamine component containing a diamine represented by the following formula (1) and an imidate thereof, and an organic solvent. Liquid crystal aligning agent.

In the formula, R 1 , R 2 , R 3 and R 4 each independently represent H, CH 3 or CF 3 , provided that one of R 1 , R 2 , R 3 and R 4 is necessarily CH 3 or Represents CF 3 ,
W 1 and W 2 represent phenylene, and phenylene is a halogen group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, a hydroxyl group, cyano Group, a dialkylamino group (the alkyl group is each independently a linear or branched alkyl group having 1 to 10 carbon atoms), a linear or branched ester group having 1 to 10 carbon atoms, or 1 carbon atom And may be substituted with a substituent selected from the group consisting of to 10 linear or branched acyl groups, carboxyl groups, aldehyde groups, nitro groups, and Boc-protected amino groups,
L1 and L2 are independently, - (O) n1 - ( CH 2) m - (O) n2 - is a divalent group represented by, n1 and n2 are independently 0 or 1, m Is an integer of 1 to 10.
The liquid crystal aligning agent of Claim 1 whose at least one of n1 and n2 is 0 in each of L1 and L2 of Formula (1).
The liquid crystal aligning agent of Claim 1 whose value of n1 + n2 + m is an even number in each of L1 and L2 of Formula (1).
The liquid crystal aligning agent according to any one of claims 1 to 3, wherein 10 to 100 mol% of the diamine component is a diamine represented by the formula (1).
A liquid crystal alignment film obtained from the liquid crystal alignment agent according to any one of claims 1 to 4.
The liquid crystal display element which has a liquid crystal aligning film of Claim 5.