KR20140041893A

KR20140041893A - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element

Info

Publication number: KR20140041893A
Application number: KR1020147004879A
Authority: KR
Inventors: 나오키 사쿠모토; 히데노리 이시이
Original assignee: 닛산 가가쿠 고교 가부시키 가이샤
Priority date: 2011-07-27
Filing date: 2012-07-27
Publication date: 2014-04-04
Also published as: TWI485489B; JP5630625B2; CN103797410A; TW201317689A; JPWO2013015407A1; KR101610562B1; CN103797410B; WO2013015407A1

Abstract

The liquid crystal aligning agent containing the polyamic acid ester and organic solvent which have a repeating unit represented by following formula (1).

(In Formula (1), X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, X ₁ and Y ₁ At least one contains at least 1 type of structure chosen from the group which consists of an amino group, an imino group, and a nitrogen-containing heterocyclic ring, R <_1> is a C1-C5 alkyl group, A <_1> and A <_2> are respectively independently hydrogen It is an C1-C10 alkyl group, an alkenyl group, or an alkynyl group which may have an atom or a substituent.)

Description

Liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element {LIQUID CRYSTAL ALIGNMENT AGENT, LIQUID CRYSTAL ALIGNMENT FILM AND LIQUID CRYSTAL DISPLAY ELEMENT}

This invention relates to the liquid crystal aligning agent containing a polyamic acid ester, the liquid crystal aligning film obtained from this liquid crystal aligning agent, and a liquid crystal display element.

In the liquid crystal display element used for a liquid crystal television, a liquid crystal display, etc., the liquid crystal aligning film for controlling the arrangement state of a liquid crystal is formed in an element normally. As a liquid crystal aligning film, the polyimide-type liquid crystal aligning film which apply | coated and baked the liquid crystal aligning agent which has a solution of polyamic acid (also called polyamic acid) and a soluble polyimide as a main component to a glass substrate etc. is mainly used until now.

With high precision of a liquid crystal display element, in a liquid crystal aligning film, in the request | requirement, such as suppression of the contrast fall of a liquid crystal display element, and reduction of an afterimage phenomenon, in addition to the expression of excellent liquid-crystal orientation and a stable pretilt angle, high voltage retention, Properties such as suppression of residual images generated by alternating current drive, small residual charges when a direct current voltage is applied, and / or rapid relaxation of accumulated residual charges by a direct current voltage are becoming increasingly important.

In the liquid crystal aligning film of a polyimide system, various proposals are made | formed in order to satisfy the above requirements. For example, as a liquid crystal aligning film with a short time until the afterimage produced | generated by DC voltage disappears, using the liquid crystal aligning agent containing the tertiary amine of a specific structure in addition to a polyamic acid or an imide group containing polyamic acid. (Refer patent document 1) and the thing using the liquid crystal aligning agent containing the soluble polyimide (imidization polymer) which used the specific diamine compound which has a bivalent organic group which has nitrogen atoms, such as a pyridine skeleton, as a raw material (patent document 2 And the like have been proposed.

Japanese Patent Laid-Open No. 9-316200 Japanese Unexamined Patent Publication No. 10-104633

The liquid crystal display element which has a liquid crystal aligning film obtained from the liquid crystal aligning agent of said patent document 1 or patent document 2 has the quick relaxation | restoration of the residual electric charge accumulate | stored by DC voltage. However, as a result of the present inventor's examination, it turned out that the liquid crystal aligning film obtained by patent document 1 and patent document 2 becomes low in light transmittance (henceforth a transmittance | permeability hereafter). When the transmittance | permeability of a liquid crystal aligning film falls, when using a liquid crystal display element, the contrast of a liquid crystal display element will fall. The decrease in contrast can be compensated for by increasing the brightness of the backlight, but a new problem arises that the power consumption of the backlight is increased by increasing the brightness of the backlight.

MEANS TO SOLVE THE PROBLEM This invention solves the said subject, Comprising: The liquid crystal aligning agent from which the relaxation of the residual charge accumulated by DC voltage is quick, and the liquid crystal aligning film with high transmittance | permeability is obtained, the liquid crystal aligning film obtained from this liquid crystal aligning agent, and a liquid crystal display element are provided. For the purpose of

According to the present inventors' studies, by using a polyamic acid ester having a repeating unit represented by formula (1) having at least one kind of structure selected from the group consisting of an amino group, an imino group and a nitrogen-containing heterocyclic ring, It was found that the relaxation of the accumulated residual charge was quick and the transmittance was increased.

In this way, the present invention

Based on said knowledge, it has the following summary.

1. The polyamic acid ester which has a repeating unit represented by following formula (1), and an organic solvent are contained, The liquid crystal aligning agent characterized by the above-mentioned.

[Chemical Formula 1]

2. Y ₁ in Formula (1) It is a divalent organic group containing at least 1 sort (s) of structure chosen from the group which consists of an amino group, an imino group, and a nitrogen-containing heterocyclic ring, The liquid crystal aligning agent of said 1 characterized by the above-mentioned.

3. Y ₁ The ratio of the repeating unit represented by the said Formula (1) which is a divalent organic group containing at least 1 sort (s) of structure chosen from the group which consists of an amino group, an imino group, and a nitrogen-containing heterocyclic ring with respect to 1 mol of all structural units, It is 40-100 mol%, The liquid crystal aligning agent of said 1 or 2 characterized by the above-mentioned.

4. Y ₁ It is at least 1 sort (s) chosen from the group which consists of a divalent organic group which has a nitrogen atom represented by following formula (YD-1)-(YD-5), The liquid crystal aligning agent in any one of said 1-3 characterized by the above-mentioned. .

(2)

(In formula (YD-1), A <_11> is a C3-C15 trivalent nitrogen-containing heterocyclic ring, Z <_1> is a hydrogen atom or a C1-C20 monovalent hydrocarbon group which may have a substituent. in (YD-2), W ₁ is a trivalent hydrocarbon group having a carbon number of 1 ~ 10, a ₁₂ are each two hydrogen of also a monovalent organic group having a carbon number of 3-15 having a nitrogen heterocyclic ring, or an amino group independently To a di-substituted amino group substituted with an aliphatic group having 1 to 6. In Formula (YD-3), W ₂ Is the carbon number of 6-15, and a divalent organic group having one or two benzene rings, W ₃ Is an alkylene group or a biphenylene group having a carbon number of ₂ ~ 5, Z 2 Is a hydrogen atom, a C1-C5 alkyl group, or a benzene ring, and a is 0 or 1. In Formula (YD-4), A ₁₃ is a divalent nitrogen-containing heterocyclic ring having 3 to 15 carbon atoms. In the formula (YD-5), A ₁₄ is a divalent nitrogen-containing heterocyclic ring having a carbon number of 3 ~ 15, W ₅ Is an alkylene group having 2 to 5 carbon atoms.)

5. A C3-C15 nitrogen atom-containing complex of A ₁₁ , A ₁₂ , A ₁₃ , and A ₁₄ described in Formulas (YD-1), (YD-2), (YD-4) and (YD-5) At least one ring selected from the group consisting of pyrrolidine, pyrrole, imidazole, pyrazole, oxazole, thiazole, piperidine, piperazine, pyridine, pyrazine, indole, benzimidazole, quinoline, isoquinoline It is a kind, The liquid crystal aligning agent in any one of said 1-4 characterized by the above-mentioned.

6. Y ₁ in Formula (1) This is at least 1 sort (s) chosen from the group which consists of a divalent organic group which has the nitrogen atom represented by following formula (YD-6)-(YD-23), The liquid crystal aligning in any one of said 1-5 characterized by the above-mentioned. My.

(3)

(M and n are the integers of 1-11, respectively, and m + n is an integer of 2-12 in a formula (YD-14), h is an integer of 1-3 in a formula (YD-19), a formula J is an integer of 0-3 in (YD-16) and (YD-23).)

7. X ₁ in Formula (1) It is at least 1 sort (s) chosen from the group which consists of a structure represented by following formula, The liquid crystal aligning agent in any one of said 1-6 characterized by the above-mentioned.

[Chemical Formula 4]

8. The liquid crystal aligning film obtained by apply | coating and baking the liquid crystal aligning agent in any one of said 1-7.

9. It has liquid crystal aligning film of 8, The liquid crystal display element characterized by the above-mentioned.

The liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention has high transmittance | permeability, and the relaxation of the residual electric charge accumulated by the direct current voltage of the liquid crystal display element provided with this liquid crystal aligning film is quick.

The polyamic acid ester which the liquid crystal aligning agent of this invention contains is a polyimide precursor which can obtain a polyimide, and is a polymer which has the site | part which can carry out the imidation reaction shown below by heating.

[Chemical Formula 5]

(R ₁ is, R in the formula ₍₁₎ Same as)

The liquid crystal aligning agent of this invention contains the polyamic acid ester which has a repeating unit (structural unit) represented by following formula (1). In addition, the polyamic acid ester which has a repeating unit represented by this Formula (1) is R <_1> , A <_1> , A <_2> , X <_1> and Y <_1>. Each of these may be a polyamic acid ester having a repeating unit represented by Formula (1) consisting of only one structure, and may also be R ₁ , A ₁ , A ₂ , X _1, and Y ₁ The polyamic acid ester which has a repeating unit represented by two or more types of Formula (1) which is two or more types of structures may be sufficient. Moreover, the polyamic acid ester which has a structure other than the repeating unit represented by Formula (1) may be sufficient as the polyamic acid ester which has a repeating unit represented by Formula (1). That is, the polyamic acid ester which consists of repeating units represented by Formula (1) of the same structure, or the polyamic acid ester which consists of repeating units represented by (1) of a different structure may be sufficient, and Formula (1) of the same structure or a different structure The polyamic acid ester which has a structure (for example, the repeating unit represented by Formula (2) mentioned later) other than the repeating unit represented by the repeating unit represented by Formula (1) may be sufficient.

[Chemical Formula 6]

In said Formula (1), R <_1> is C1-C5, Preferably it is an alkyl group of 1-2, More preferably, it is a methyl group.

In Formula (1), A <_1> and A <_2> are respectively independently a hydrogen atom or a C1-C10 alkyl group, alkenyl group, or alkynyl group which may have a substituent. Specific examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, t-butyl group, hexyl group, octyl group, decyl group, cyclopentyl group, cyclohexyl group and bicyclohexyl group. As an alkenyl group, what substituted one or more CH-CH structures which exist in said alkyl group by C = C structure is mentioned, More specifically, a vinyl group, an allyl group, 1-propenyl group, isopropenyl group , 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, 2-hexenyl group, cyclopropenyl group, cyclopentenyl group, cyclohexenyl group and the like. As the alkynyl group, there may be mentioned that the substitution of one or more CH ₂ -CH ₂ structures present in the alkyl group of the structure with C≡C, more specifically, ethynyl group, 1-propynyl group, 2-propynyl group Can be mentioned.

Said alkyl group, alkenyl group, and alkynyl group may have a substituent as a whole as C1-C10, and may form a ring structure by a substituent further. In addition, forming a ring structure by a substituent means that a substituent or a part of a substituent and a parent skeleton (that is, the atom which comprises A <_1> or A <_2> ) couple | bonds and becomes a ring structure.

Examples of the substituent include halogen group, hydroxyl group, thiol group, nitro group, aryl group, organooxy group, organothio group, organosilyl group, acyl group, ester group, thioester group, phosphate ester group, amide group, alkyl group, Alkenyl group and alkynyl group are mentioned.

As a halogen group which is a substituent, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned.

A phenyl group is mentioned as an aryl group which is a substituent. The other substituent mentioned above may further substitute by this aryl group.

As an organooxy group which is a substituent, the structure represented by O-R can be shown. This R may be same or different and can illustrate an alkyl group, an alkenyl group, an alkynyl group, an aryl group, etc. which were mentioned above. The substituent mentioned above may further substitute by such R. Specific examples of the organooxy group include a methoxy group, ethoxy group, propyloxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group and the like.

As an organothio group which is a substituent, the structure represented by -S-R can be shown. As said R, the alkyl group, alkenyl group, alkynyl group, aryl group, etc. which were mentioned above can be illustrated. The substituent mentioned above may further substitute by such R. Specific examples of the organothio group include methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, hexylthio group, heptylthio group, octylthio group and the like.

As an organosilyl group which is a substituent, the structure represented by -Si- (R) ₃ can be shown. This R may be same or different and can illustrate an alkyl group, an alkenyl group, an alkynyl group, an aryl group, etc. which were mentioned above. The substituent mentioned above may further substitute by such R. Specific examples of the organosilyl group include trimethylsilyl group, triethylsilyl group, tripropylsilyl group, tributylsilyl group, tripentylsilyl group, trihexylsilyl group, pentyldimethylsilyl group, hexyldimethylsilyl group, and the like. have.

As an acyl group which is a substituent, the structure represented by -C (O) -R can be shown. As this R, the alkyl group, alkenyl group, aryl group, etc. which were mentioned above can be illustrated. The substituent mentioned above may further substitute by such R. Specific examples of the acyl group include formyl group, acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, benzoyl group and the like.

As ester group which is a substituent, the structure represented by -C (O) O-R or -OC (O) -R can be shown. As said R, the alkyl group, alkenyl group, alkynyl group, aryl group, etc. which were mentioned above can be illustrated. The substituent mentioned above may further substitute by such R.

As a thioester group which is a substituent, the structure represented by -C (S) O-R or -OC (S) -R can be shown. As said R, the alkyl group, alkenyl group, alkynyl group, aryl group, etc. which were mentioned above can be illustrated. The substituent mentioned above may further substitute by such R.

As a phosphate ester group which is a substituent, the structure represented by -OP (O)-(OR) ₂ can be shown. This R may be same or different and can illustrate an alkyl group, an alkenyl group, an alkynyl group, an aryl group, etc. which were mentioned above. The substituent mentioned above may further substitute by such R.

The substituent is an amide group, a structure represented by -C (O) NH _2, or, -C (O) NHR, -NHC (O) R, -C (O) N (R) 2, -NRC (O) R Can be represented. This R may be same or different and can illustrate an alkyl group, an alkenyl group, an alkynyl group, an aryl group, etc. which were mentioned above. The substituent mentioned above may further substitute by such R. An aryl group is mentioned as a substituent which substitutes the hydrogen atom of R. As an aryl group which is this substituent, the thing similar to the aryl group mentioned above is mentioned. The other substituent mentioned above may further substitute by this aryl group.

As an alkyl group which is a substituent, the thing similar to the alkyl group mentioned above is mentioned. The other substituent mentioned above may further substitute by this alkyl group.

As an alkenyl group which is a substituent, the same thing as the alkenyl group mentioned above is mentioned. The other substituent mentioned above may further substitute by this alkenyl group.

As an alkynyl group which is a substituent, the thing similar to the alkynyl group mentioned above is mentioned. The other substituent mentioned above may further substitute by this alkynyl group.

In general, when a bulky structure is introduced, the reactivity of the amino group and the liquid crystal alignment property may be lowered. As A ₁ and A ₂ , an alkyl group having 1 to 5 carbon atoms which may have a hydrogen atom or a substituent is more preferable. Hydrogen atom, methyl group or ethyl group is particularly preferable.

In Formula (1), X <_1> is a tetravalent organic group, Y <_1> is a divalent organic group, In the group which consists of an amino group, an imino group, and a nitrogen-containing heterocyclic ring in at least one among X <_1> and Y <_1> , It contains at least one kind of structure selected. Y ₁ from the viewpoint of availability of raw material monomers (ie, diamine compounds and tetracarboxylic acid derivatives) and simplicity of production of raw material monomers It is preferable that it is a divalent organic group containing at least 1 type of structure chosen from the group which consists of this amino group, an imino group, and a nitrogen-containing heterocyclic ring. In addition, an organic group is a hydrocarbon group which may have N or O, for example.

Y ₁ The amino group, if an imino group, and also a divalent organic group containing a structure of at least one kind of element selected from the group consisting of a nitrogen heterocyclic ring, as the structure of the Y _1, an amino group, already selected from the group consisting of a group and a nitrogen-containing heterocyclic As long as it contains at least 1 type of structure, the structure is not specifically limited. If it dares to give the specific example, the divalent organic group containing the at least 1 sort (s) of structure chosen from the group which consists of an amino group, an imino group, and a nitrogen-containing heterocyclic ring represented by following formula (YD-1) (YD-5)- Can be mentioned.

(7)

In formula (YD-1), A <_11> is a C3-C15 trivalent nitrogen-containing heterocyclic ring, Z <_1> is a C1-C20 monovalent hydrocarbon group which may have a hydrogen atom or a substituent.

In the formula (YD-2), W ₁ is a trivalent hydrocarbon group having a carbon number of 1 ~ 10, A ₁₂ are the two hydrogens of the box a monovalent organic group having a carbon number of 3-15 having a nitrogen heterocyclic ring, or an amino group Each independently represent a di-substituted amino group substituted with an aliphatic group having 1 to 6 carbon atoms.

In the formula (YD-3), W ₂ Is the carbon number of 6-15, and a divalent organic group having one or two benzene rings, W ₃ Is an alkylene group or a biphenylene group having a carbon number of ₂ ~ 5, Z 2 Is a hydrogen atom, a C1-C5 alkyl group, or a benzene ring, and a is an integer of 0-1.

In Formula (YD-4), A ₁₃ is a divalent nitrogen-containing heterocyclic ring having 3 to 15 carbon atoms.

In the formula (YD-5), A ₁₄ is a divalent nitrogen-containing heterocyclic ring having a carbon number of 3 ~ 15, W ₅ Is a C2-C5 alkylene group.

Expression as (YD-1), (YD -2), (YD-4) , and _{A 11, A 12, A 13} , and also having a carbon number of 3 to 15 nitrogen heterocyclic ring of A ₁₄ in (YD-5), known As long as the structure is not particularly limited, pyridine, pyrrole, imidazole, pyrazole, oxazole, thiazole, piperidine, piperazine, pyridine, pyrazine, indole, benzimidazole, quinoline, Isoquinoline is mentioned, piperazine, piperidine, indole, benzoimidazole, imidazole, carbazole, and pyridine are more preferred.

Moreover, as a specific example of Y <_{1> which} is a divalent organic group containing at least 1 sort (s) of structure chosen from the group which consists of an amino group, an imino group, and a nitrogen-containing heterocyclic ring in Formula (1), following formula (YD-6)- The divalent organic group which has the nitrogen atom represented by (YD-23) is mentioned, The residual charge at the time of applying the direct current voltage when it used as a liquid crystal display element is small, and / or of the accumulated residual charge by DC voltage. Since relaxation is especially quick, Formula (YD-16)-Formula (YD-23) are especially preferable.

[Chemical Formula 8]

In formula (YD-14), m and n are the integers of 1-11, respectively, and m + n is an integer of 2-12. H is an integer of 1-3 in a formula (YD-19), j is an integer of 0-3 in a formula (YD-16) and (YD-23).

In the polyamic acid ester having a repeating unit represented by the formula _(1), Y 1 The ratio of the repeating unit represented by Formula (1) which is a divalent organic group which has at least 1 type of structure chosen from the group which consists of this amino group, an imino group, and a nitrogen-containing heterocyclic ring is 40-100 with respect to 1 mol of all structural units. It is preferable that it is mol%, More preferably, it is 60-100 mol%, More preferably, it is 80-100 mol%. In addition, all the structural units are all the structural units which comprise the polyamic acid ester which has a repeating unit represented by Formula (1), and specifically, the total amount (remo unit basis) of a repeating unit represented by Formula (1), or a formula When it contains structures other than the repeating unit represented by (1), it is a total amount (molar standard) of the repeating unit represented by Formula (1) and structures other than the repeating unit represented by Formula (1).

In the formula (1), Y ₁ In the case of a divalent organic group having at least one kind of structure selected from the group consisting of an amino group, an imino group, and a nitrogen-containing heterocycle, the structure is not particularly limited as long as X ₁ is a tetravalent organic group, More than a kind may be mixed. Specific examples of X ₁ include X-1 to X-46 shown below. Among these, from the availability of the raw material monomer, X ₁ is, each independently, X-1, X-2 , X-3, X-4, X-5, X-6, X-8, X-16, X-19, X-21, X-25, X-26, X-27, X-28, X-32, or X-46 are preferred. In order to obtain a liquid crystal aligning film of higher transmittance, X-1, X-2, X-3, X-4, X-5, X-6, X-8, X-16, X-25, having an aliphatic structure Or X-46 is more preferable, and X-1 or X-2 is especially preferable. On the other hand, in order to obtain a liquid crystal aligning film faster in alleviating the residual charges accumulated in the liquid crystal display element by the DC voltage, X-26, X-27 or X-28 having an aromatic structure is more preferable, and X-26 or X-32 is particularly preferred.

[Chemical Formula 9]

[Chemical formula 10]

(11)

[Chemical Formula 12]

Moreover, the polyamic acid ester which has a repeating unit represented by Formula (1) used for this invention may have structures other than the repeating unit represented by Formula (1), unless the effect of this invention is impaired. As a structure other than the repeating unit represented by Formula (1), the repeating unit (structural unit) represented by following formula (2) is mentioned.

[Chemical Formula 13]

In Formula (2), A <_1> , A <_2> and R <_1> are the same definition as Formula (1), X is a tetravalent organic group and Y is a divalent organic group.

X also includes a preferable example, X ₁ Same definition as

Y is a divalent organic group, The structure is not specifically limited, Two or more types may be mixed. If the specific example is shown, following Y-1 to Y-100 will be mentioned.

Especially, in order to acquire favorable liquid-crystal orientation, it is preferable to introduce the structure with high linearity to polyamic acid ester, and as Y, Y-7, Y-21, Y-22, Y-23, Y-25, Y -26, Y-27, Y-43, Y-44, Y-45, Y-46, Y-48, Y-63, Y-71, Y-73, Y-74, Y-75, Y-98 , Y-99, Y-100 are more preferable. In order to increase the pretilt angle, it is preferable to introduce a structure having a long chain alkyl group, an aromatic ring, an aliphatic ring, a steroid skeleton, or a combination thereof in the side chain to the polyamic acid ester, and as Y ₁ , , Y-76, Y-77, Y-78, Y-79, Y-80, Y-81, Y-82, Y-83, Y-84, Y-85, Y-86, Y-87, Y More preferred are -88, Y-89, Y-90, Y-91, Y-92, Y-93, Y-94, Y-95, Y-96, or Y-97. Arbitrary pretilt angles can be expressed by making these structures into 1-50 mol% with respect to the structure whole quantity derived from the diamine compound which is a raw material of polyamic acid ester. That is, arbitrary pretilt angles can be expressed by adding 1-50 mol% of diamine which has these structures with respect to the diamine compound whole quantity which is a raw material of polyamic acid ester.

[Chemical Formula 14]

[Chemical Formula 15]

[Chemical Formula 16]

[Chemical Formula 17]

[Chemical Formula 18]

[Chemical Formula 19]

[Chemical Formula 20]

[Chemical Formula 21]

[Chemical Formula 22]

(23)

&Lt; EMI ID =

(25)

In the polyamic acid ester which has a repeating unit represented by Formula (1) used for this invention, the ratio of the structural unit represented by Formula (2) is a polya which has a repeating unit represented by Formula (1) among all the structural units. 0-40 mol% is preferable with respect to 1 mol of total amounts of all the structural units which comprise a mic acid ester, More preferably, it is 0-20 mol%, More preferably, it is 0-10 mol%.

The polyamic acid ester is mentioned below using tetracarboxylic-acid derivatives, such as tetracarboxylic dianhydride, tetracarboxylic-acid diester, and dichloride tetracarboxylic-acid diester, and a diamine compound (henceforth simply a diamine). It can synthesize | combine by the method of (1)-(3) shown. As a diamine compound which is a raw material for obtaining the polyamic acid ester which has a repeating unit represented by Formula (1), following formula (a1) is mentioned. Moreover, in order to obtain the polyamic acid ester which also has a repeating unit represented by Formula (2), the diamine compound represented by following formula (a2) may be used as a raw material, for example. Moreover, the following formula (b1)-(b3) are mentioned as a tetracarboxylic-acid derivative which is a raw material for obtaining the polyamic acid ester which has a repeating unit represented by Formula (1). In addition, in order to obtain the polyamic acid ester which has a repeating unit represented by Formula (2), it is X <_1> in following formula (b1)-(b3), for example. A tetracarboxylic acid derivative having X as the material may be used as the raw material.

(26)

(In formula (a1) and (a2), A <_1> , A <_2> , Y <_1> and Y are the same as Formula (1) and Formula (2), respectively.)

(27)

(In formula (b1)-(b3), R <_1> and X <_1> are the same as that of Formula (1), respectively.)

(1) Synthesis from polyamic acid

The polyamic acid ester can be synthesized by esterifying a polyamic acid obtained from a tetracarboxylic acid dianhydride and a diamine.

Specifically, the polyamic acid and esterification agent obtained by reacting tetracarboxylic dianhydride and diamine are -20 ° C to 150 ° C in the presence of an organic solvent, preferably 0 ° C to 50 ° C for 30 minutes to 24 hours. Preferably, it can synthesize | combine by making it react for 1 to 4 hours.

As an esterification agent, what can be easily removed by refinement | purification is preferable, and N, N- dimethylformamide dimethyl acetal, N, N- dimethylformamide diethyl acetal, N, N- dimethylformamide dipropyl acetal, N , N-dimethylformamidedienepentylbutylacetal, N, N-dimethylformamidedi-t-butylacetal, 1-methyl-3-p-tolyltriagen, 1-ethyl-3-p-tolyltriagen, 1-propyl-3-p-tolyltriazene, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride, etc. are mentioned. As for the addition amount of an esterifying agent, 2-6 molar equivalent is preferable with respect to 1 mol of repeating units of the polyamic acid obtained by reaction of tetracarboxylic dianhydride and diamine.

The solvent used for the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone in terms of solubility of the polymer (polyamic acid or polyamic acid ester). You may use 1 type or in mixture of 2 or more types. 1-30 mass% is preferable, and, as for the density | concentration at the time of a synthesis | combination from a viewpoint that a precipitation of a polymer does not occur easily and a high molecular weight body is easy to obtain, 5-20 mass% is more preferable.

(2) Synthesis by reaction of tetracarboxylic acid diester dichloride with diamine

Polyamic acid esters can be synthesized from tetracarboxylic acid diester dichloride and diamines.

Specifically, tetracarboxylic acid diester dichloride and diamine are present in the presence of a base and an organic solvent at -20 ° C to 150 ° C, preferably 0 ° C to 50 ° C, for 30 minutes to 24 hours, preferably 1 to It can synthesize | combine by making it react for 4 hours.

As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable for the reaction to proceed mildly. It is preferable that the addition amount of a base is the quantity which is easy to remove, and is 2-4 times mole with respect to tetracarboxylic-acid diester dichloride from a viewpoint that a high molecular weight is easy to obtain.

The solvent used for said reaction is N-methyl- 2-pyrrolidone and (gamma) -butyrolactone by the solubility of a raw material monomer (tetracarboxylic acid derivative, a diamine compound), and a polymer (polyamic acid or polyamic acid ester). This is preferable and these may use 1 type or in mixture of 2 or more types. 1-30 mass% is preferable, and, as for the polymer concentration at the time of synthesis | combination from a viewpoint that a precipitation of a polymer does not occur easily and a high molecular weight body is easy to be obtained, 5-20 mass% is more preferable. Moreover, in order to prevent the hydrolysis of tetracarboxylic-acid diester dichloride, it is preferable that the solvent used for the synthesis | combination of a polyamic acid ester is dehydrated as much as possible, and it is preferable to prevent mixing of external air in nitrogen atmosphere. .

(3) When synthesized from tetracarboxylic acid diester and diamine

The polyamic acid ester can be synthesized by polycondensation of a tetracarboxylic acid diester and a diamine.

Specifically, the tetracarboxylic acid diester and the diamine are reacted in the presence of a condensing agent, a base and an organic solvent at 0 ° C to 150 ° C, preferably 0 ° C to 100 ° C for 30 minutes to 24 hours, For 15 hours.

Examples of the condensing agent include triphenyl phosphite, dicyclohexyl carbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N'-carbonyldiimidazole, and dimethoxy-1 , 3,5-triazinylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethyluroniumtetrafluoroborate, O- (benzotriazole- 1-yl) -N, N, N ', N'-tetramethyluronium hexafluorophosphate, (2,3-dihydroxy-2-thioxo-3-benzooxazoyl) phosphonic acid diphenyl and the like Can be used. It is preferable that the addition amount of a condensing agent is 2-3 times mole with respect to tetracarboxylic-acid diester.

As the base, tertiary amines such as pyridine and triethylamine can be used. The addition amount of base is an amount which is easy to remove, and 2-4 times mole is preferable with respect to a diamine compound from a viewpoint that a high molecular weight body is easy to obtain.

In addition, in the above reaction, the reaction proceeds efficiently by adding Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. As for the addition amount of a Lewis acid, 0-1.0 times mole is preferable with respect to a diamine compound.

Since the high molecular weight polyamic acid ester is obtained among the synthesis | combining method of said three polyamic acid ester, the synthesis method of said (1) or said (2) is especially preferable.

The solution of the polyamic acid ester obtained as mentioned above can deposit a polymer (polyamic acid ester) by inject | pouring into a poor solvent, stirring well. After several times of precipitation and washing with a poor solvent, the purified polyamic acid ester powder can be obtained at room temperature or by heating and drying. Although the poor solvent is not specifically limited, Water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene, etc. are mentioned.

The weight average molecular weight of the polyamic acid ester which has a repeating unit represented by Formula (1) becomes like this. Preferably it is 5,000-300,000, More preferably, it is 10,000-200,000. In addition, the number average molecular weight is preferably 2,500 to 150,000, and more preferably 5,000 to 100,000.

The liquid crystal aligning agent of this invention contains the polyamic acid ester which has a repeating unit represented by said formula (1), and an organic solvent. Thus, the liquid crystal aligning film obtained from the liquid crystal aligning agent containing the polyamic acid ester which has a repeating unit represented by Formula (1) has a high transmittance | permeability, and the residual accumulated by DC voltage of the liquid crystal display element provided with this liquid crystal aligning film. Ease of charge is fast.

Although it is not necessarily clear about why the subject of this invention is solved by using the liquid crystal aligning agent containing the polyamic acid ester which has a repeating unit represented by Formula (1), it is almost considered as follows.

In general, the higher the imidation ratio of the imidized polymer (polyimide), the longer the absorption wavelength is. Therefore, the film (liquid crystal alignment film) obtained by baking the liquid crystal aligning agent is colored.

On the other hand, since the imidation by heating (firing) hardly advances the polyamic acid ester which has a repeating unit represented by Formula (1) contained in the liquid crystal aligning agent of this invention, coloring by imidation is reduced. It is guessed that the liquid crystal aligning film with high transmittance | permeability is obtained.

Moreover, the examination by this inventor showed that the compound which has an amino group, an imino group, and a nitrogen-containing heterocyclic ring was oxidized and colored by the influence of oxygen and water in air.

And since the liquid crystal aligning agent containing the soluble polyimide which imidated polyamic acid or a part of polyamic acid has a highly polar carboxyl group in a polymer (polyamic acid or polyimide), interaction with water is strong, and a polymer It is expected to contain moisture in the water. Moreover, the said polymer produces | generates water as a leaving group at the time of imidation by heating. It is thought that this water promotes oxidation of the nitrogen atom contained in the structure having an amino group, an imino group, and a nitrogen-containing heterocyclic ring, and the transmittance of the resulting membrane is lowered.

On the other hand, the ester group in the polyamic acid ester which has a repeating unit represented by Formula (1) contained in the liquid crystal aligning agent of this invention is lower in polarity than a carboxyl group, and is a structure which is hard to contain a water molecule. In addition, polyamic acid ester produces | generates an alcohol as a leaving group at the time of imidation by heating. Therefore, it is thought that the promoting effect | action of the oxidation by the water of the nitrogen atom contained in the structure which has an amino group, an imino group, and a nitrogen-containing heterocyclic ring is reduced, and the liquid crystal aligning film with high transmittance | permeability is obtained.

Moreover, since the liquid crystal aligning agent of this invention contains the polyamic acid ester which has a repeating unit represented by Formula (1) which has a structure which has an amino group, an imino group, and a nitrogen-containing heterocyclic ring, the liquid crystal display provided with the liquid crystal aligning film obtained It is considered that the device can accelerate the relaxation of the residual charge accumulated by the DC voltage.

In the above point, the liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention has a high transmittance | permeability, and it is thought that the liquid crystal display element provided with this liquid crystal aligning film can accelerate | stimulate the residual charge accumulated by DC voltage quickly.

In Patent Document 1, but the imide group-containing liquid crystal containing a polyamic acid base I, the acid imide group-containing polyamide of the reference 1, the formula (1) of the repeating unit represented by Y ₁ Or X ₁ It does not have an imide group, and of course, Patent Document 1 does not describe the polyamic acid ester at all. Moreover, although the liquid crystal aligning agent containing the imidation polymer (that is, polyimide) of the structure which has a bivalent organic group which has nitrogen atoms, such as a pyridine ring, is described in patent document 2, patent document 2 is referred to as a polyamic acid ester. It is not described at all. And in the liquid crystal aligning agent of patent document 1 or patent document 2, the transmittance | permeability which is an effect of this invention is high, and relaxation of the residual electric charge accumulated by the direct current voltage of the liquid crystal display element provided with the said liquid crystal aligning film can be made quick. The effect of the present invention is not obtained.

The liquid crystal aligning agent of this invention is a form of the solution which the polyamic acid ester which has a repeating unit represented by said Formula (1) melt | dissolved in the organic solvent. As long as it has such a form, when the polyamic acid ester is synthesize | combined in an organic solvent, the reaction solution obtained itself may be sufficient, and what diluted this reaction solution with the appropriate solvent may be sufficient as it. Moreover, when polyamic acid ester is obtained as a powder, it may be made to melt | dissolve this in the organic solvent and set it as the solution.

Although content (concentration) of the polyamic acid ester (henceforth a polymer.) In the liquid crystal aligning agent of this invention can be suitably changed also by setting of the thickness of the liquid crystal aligning film to form, application | coating without uniformity and a defect From the point of forming a film, 0.5 mass% or more is preferable with respect to an organic solvent, and 15 mass% or less is preferable at the point of storage stability of a solution, More preferably, it is 1-10 mass% to be. In this case, in the case of preparing a thick solution of the polymer in advance and using it as a liquid crystal aligning agent, it may be diluted. 10-30 mass% is preferable, and, as for the density | concentration of the rich solution of such a polymer component, 10-15 mass% is more preferable. Moreover, you may heat when melt | dissolving the powder of a polymer component in an organic solvent and manufacturing a solution. 20 to 150 degreeC is preferable and 20 to 80 degreeC of heating temperature is especially preferable. In addition, a polymer component is a polymer other than the polyamic acid ester which has a repeating unit represented by Formula (1), and the polyamic acid ester which does not have a repeating unit represented by Formula (1) to contain as needed, and a polyamic acid ester.

The said 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 and N-ethyl-2-pyrroli Don, N-methylcaprolactam, 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, if individual, if it is a solvent which cannot melt | dissolve a polymer component uniformly, or if it is a range in which a polymer does not precipitate, you may mix with said organic solvent.

In addition to the organic solvent for dissolving a polymer component, the liquid crystal aligning agent of this invention 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. Such a solvent generally uses a solvent having a lower surface tension than the organic solvent. Specific examples thereof include ethyl cellosolve, butyl cellosolve, butyl cellosolve acetate, 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, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactic acid methyl ester, lactic acid ethyl ester, lactic acid n-propyl ester, lactic acid n-butyl ester, iso lactic acid Milester etc. are mentioned. These solvents may be used in combination of two or more.

Polymers other than the polyamic acid ester which have a repeating unit represented by Formula (1) in the liquid crystal aligning agent of this invention as long as it is a range in which the effect of this invention is not inhibited other than the above, specifically, it is represented by Formula (1) Silane coupling agent for the purpose of improving the adhesion between the dielectric or conductive material for changing electrical properties such as polyamic acid ester having no unit, polymers other than polyamic acid ester, dielectric constant and conductivity of liquid crystal alignment film, liquid crystal alignment film and substrate You may add the crosslinking | crosslinked compound of the objective which raises the hardness and the density of a film at the time of using as a liquid crystal aligning film.

The liquid crystal aligning film of this invention is a film | membrane obtained by apply | coating the said liquid crystal aligning agent to a board | substrate, drying as needed, and baking. As a board | substrate which apply | coats the liquid crystal aligning agent of this invention, if it is a board | substrate with high transparency, it will not specifically limit, Plastic substrates, such as a glass substrate, a silicon nitride substrate, an acryl substrate, a polycarbonate substrate, etc. can be used, and ITO (Indium) for liquid crystal drive is used. It is preferable to use a substrate on which a Tin Oxide) electrode or the like is formed from the viewpoint of simplification of the process. In the reflective liquid crystal display element, only one substrate may be used as long as it is opaque, such as a silicon wafer, and the electrode in this case may use a material that reflects light such as aluminum.

As a coating method of the liquid crystal aligning agent of this invention, a spin coat method, the printing method, the inkjet method, etc. are mentioned. The drying after apply | coating the liquid crystal aligning agent of this invention, and the baking process can select arbitrary temperature and time. Usually, it is dried at 50 to 120 ° C for 1 to 10 minutes to sufficiently remove the contained organic solvent, and then baked at 150 to 300 ° C for 5 to 120 minutes. In addition, a drying process does not need to be performed. Although the thickness of the coating film after baking is not specifically limited, Since the reliability of a liquid crystal display element may fall when too thin, it is 5-300 nm, Preferably it is 10-200 nm.

As a method of orientation-processing the obtained liquid crystal aligning film, the rubbing method, the photo-alignment processing method, etc. are mentioned. In addition, in this invention, it is not necessary to perform an orientation process.

As a specific example of the photo-alignment processing method, the radiation which deflected to the said coating film surface in the fixed direction is irradiated, and if necessary, further heat-processes at the temperature of 150-250 degreeC, and gives a liquid crystal aligning ability. Can be. As the radiation, ultraviolet rays and visible rays having a wavelength of 100 nm to 800 nm can be used. Among these, ultraviolet rays having a wavelength of 100 nm to 400 nm are preferable, and those having a wavelength of 200 nm to 400 nm are particularly preferable. Moreover, in order to improve the liquid-crystal orientation, you may irradiate a radiation, heating a coating film substrate at 50-250 degreeC. 1-10,000mJ / cm <2> is preferable and, as for the irradiation amount of the said radiation, 100-5,000mJ / cm <2> is especially preferable. The liquid crystal aligning film manufactured as mentioned above can align a liquid crystal molecule stably in a fixed direction.

The liquid crystal display element of this invention obtains the board | substrate with which the liquid crystal aligning film was formed from the liquid crystal aligning agent of this invention by said method, and after performing an orientation process as needed, manufactures a liquid crystal cell by a well-known method, and a liquid crystal display element. I did it.

Although the manufacturing method of a liquid crystal cell is not specifically limited, If an example is given, the pair of board | substrates with which the liquid crystal aligning film was formed make a liquid crystal aligning film surface inside, Preferably it is 1-30 micrometers, More preferably, it is 2-10 micrometers After the spacers are placed in between, the surroundings are fixed with a sealing agent, and a liquid crystal is injected and sealed. There is no restriction | limiting in particular about the method of liquid crystal encapsulation, The vacuum method which injects a liquid crystal after making the inside of the produced liquid crystal cell into pressure reduction, the dropping method etc. which perform sealing after dripping a liquid crystal can be illustrated.

Example

Although an Example is given to the following and this invention is demonstrated in more detail, this invention is not limited to these. The symbol of the compound used by the present Example and the comparative example and the measuring method of each characteristic are as follows.

DE-1: the following formula (DE-1)

DE-2: the following formula (DE-2)

DE-3: The following formula (DE-3)

DA-1: The following formula (DA-1)

DA-2: The following formula (DA-2)

DA-3 ： The following formula (DA-3)

NMP: N-methyl-2-pyrrolidone

BCS: Butyl Cellosolve

GBL: γ-butyrolactone

(28)

(Wherein Me represents a methyl group.)

[Chemical Formula 29]

(Wherein Me represents a methyl group.)

[Viscosity]

In the synthesis example and the comparative synthesis example, the viscosity of the polyamic acid ester and the polyamic acid solution is 1.1 mL of sample volume and Contorter TE-1 (1 ° 34 ') using an E-type viscometer TVE-22H (manufactured by Toki Kogyo Co., Ltd.). , R24) and a temperature of 25 ° C.

[Molecular Weight]

In addition, the molecular weight of polyamic acid ester is measured by GPC (room gel permeation chromatography) apparatus, and it is a number average molecular weight (henceforth Mn.) And a weight average molecular weight (henceforth Mw as polyethyleneglycol and polyethylene oxide conversion value. Calculated.

GPC device ： Shodex Corporation (GPC-101)

Column: Shodex (KD803, KD805 serial)

Column temperature: 50 ° C

Eluent: N, N-dimethylformamide (as additive, lithium bromide-hydrate (LiBr.H ₂ O) is 30 mmol / l, phosphoric acid and anhydrous crystals (o-phosphate) is 30 mmol / l, tetrahydrofuran (THF A) 10 ml / l)

Flow rate: 1.0 ml / min

Standard sample for calibration curve preparation: TSK standard polyethylene oxide (weight average molecular weight (Mw) about 900,000, 150,000, 100,000, 30,000) by Toso Corporation, and polyethylene glycol (peak top molecular weight (Mp) about 12,000, 4,000 by polymer laboratories , 1,000). The measurement measures 2 samples of the sample which mixed four types of 900,000, 100,000, 12,000, and 1,000, and the sample which mixed three types of 150,000, 30,000, and 4,000, respectively, in order to avoid that a peak overlaps.

(Synthesis Example 1)

3.39 g (13.0 mmol) of DE-2 and 1.69 g (5.99 mmol) of DE-3 were added to the 200 mL four-necked flask with a stirring apparatus, 84.69g of NMP was added, and it stirred and dissolved. Subsequently, 4.45 g (44.0 mmol) and 3.99 g (20.0 mmol) of 4,4'- diamino diphenylamine were added, and it stirred and dissolved in triethylamine. While stirring this solution, 16.87 g (44.0 mmol) of (2,3-dihydroxy-2-thioxo-3-benzooxazoyl) phosphonic acid diphenyl were added, and 11.63 g of NMP was further added, and it water-cooled. The reaction was carried out for 4 hours. The obtained polyamic acid ester solution was thrown into 760 g of 2-propanol while stirring, the precipitate precipitate was collected by filtration, washed five times with 253 g of 2-propanol and dried to obtain a polyamic acid ester resin powder. . The molecular weight of this polyamic acid ester was Mn = 13646 and Mw = 28242.

1.78 g of the obtained polyamic acid ester resin powder was taken into a 50 ml Erlenmeyer flask, 16.02 g of NMP was added, and stirred at room temperature for 24 hours to dissolve, thereby obtaining a polyamic acid ester solution (PAE-1).

(Synthesis Example 2)

3.39 g (13.0 mmol) of DE-2 and 1.69 g (5.99 mmol) of DE-3 were taken into a 200 mL four-necked flask with a stirring device, 84.53 g of NMP was added, and the mixture was stirred and dissolved. Subsequently, 4.45 g (44.0 mmol) and 4.26 g (20.0 mmol) of DA-1 were added, and it stirred and dissolved. While stirring this solution, 16.87 g (44.0 mmol) of (2,3-dihydroxy-2-thioxo-3-benzooxazoyl) phosphonic acid diphenyl were added, 12.02 g of NMP were further added, and water cooling was carried out. The reaction was carried out for 4 hours. The obtained polyamic acid ester solution was thrown into 781 g of 2-propanol while stirring, and the precipitate deposited was collected by filtration, washed five times with 260 g of 2-propanol, and dried to obtain a polyamic acid ester resin powder. . The molecular weight of this polyamic acid ester was Mn = 10326 and Mw = 21332.

2.10 g of the obtained polyamic acid ester resin powder was taken into a 50 ml Erlenmeyer flask, 18.98 g of NMP was added, and stirred at room temperature for 24 hours to dissolve, thereby obtaining a polyamic acid ester solution (PAE-2).

(Synthesis Example 3)

1.69 g (6.50 mmol) of DE-2 and 0.85 g (3.00 mmol) of DE-3 were added to a 200 mL four-necked flask equipped with a stirring device, and 61.89 g of NMP was added thereto, followed by stirring to dissolve. Subsequently, 2.23 g (22.0 mmol) and 3.92 g (9.99 mmol) of DA-3 were added, and it stirred and dissolved in triethylamine. While stirring the solution, 8.43 g (22.0 mmol) of (2,3-dihydroxy-2-thioxo-3-benzooxazoyl) phosphonic acid diphenyl was added, and 8.50 g of NMP was further added, followed by water cooling. The reaction was carried out for 4 hours. The obtained polyamic acid ester solution was thrown into 525 g of 2-propanol while stirring, the precipitate precipitate was collected by filtration, washed five times with 175 g of 2-propanol, and dried to obtain a polyamic acid ester resin powder. . The molecular weight of this polyamic acid ester was Mn = 22044 and Mw = 56569.

2.11 g of the obtained polyamic acid ester resin powder was taken into a 50 ml Erlenmeyer flask, 18.99 g of NMP was added, and stirred at room temperature for 24 hours to dissolve to obtain a polyamic acid ester solution (PAE-3).

(Synthesis Example 4)

A 300 ml four-necked flask with a stirring device was placed in a nitrogen atmosphere, and 3.02 g (11.3 mmol) of DA-2 was added, 108 g of NMP and 1.99 g (25.2 mmol) of pyridine were added as a base, followed by stirring to dissolve. . Next, 3.42 g (10.5 mmol) of DE-1 was added stirring this diamine solution, and it reacted under water cooling for 4 hours. The obtained polyamic acid ester solution was thrown into 468 g of 2-propanol while stirring, and the precipitate deposited was collected by filtration, washed five times with 234 g of 2-propanol, and dried to obtain a polyamic acid ester resin powder. . The molecular weight of this polyamic acid ester was Mn = 16548 and Mw = 37836.

1.79 g of the obtained polyamic acid ester resin powder was taken into a 50 ml Erlenmeyer flask, 16.11 g of NMP was added, and stirred at room temperature for 24 hours to dissolve to obtain a polyamic acid ester solution (PAE-4).

(Synthesis Example 5)

A 300 ml four-necked flask equipped with a stirring device was placed in a nitrogen atmosphere, 2.02 g (10.1 mmol) of 4,4'-diaminodiphenylamine and 1.02 g (6.70 mmol) of 3,5-diaminobenzoic acid were added thereto. 135 g of NMP and 2.99 g (37.7 mmol) of pyridine were added as a base, and it stirred and dissolved. Next, 5.14 g (15.8 mmol) of DE-1 was added stirring this diamine solution, and it reacted under water cooling for 4 hours. The obtained polyamic acid ester solution was thrown into 584 g of 2-propanol while stirring, the precipitate precipitate was collected by filtration, washed 5 times with 292 g of 2-propanol and dried to obtain a polyamic acid ester resin powder. . The molecular weight of this polyamic acid ester was Mn = 9724 and Mw = 19380.

3.56 g of the obtained polyamic acid ester resin powder was taken into a 50 ml Erlenmeyer flask, 32.09 g of NMP was added, and stirred at room temperature for 24 hours to dissolve to obtain a polyamic acid ester solution (PAE-5).

(Comparative Synthesis Example 1)

3.99 g (20.0 mmol) of 4,4'-diaminodiphenylamine was added to a 100 ml four-necked flask with a stirrer and a nitrogen inlet tube, 63.9 g of NMP was added thereto, and stirred and dissolved while sending nitrogen. I was. While stirring the diamine solution, 2.63 g (13.4 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1.30 g (5.96 mmol) of pyromellitic dianhydride were added, and the solid content concentration NMP was added so that it might be 10 mass%, and it stirred at room temperature for 24 hours, and obtained the polyamic-acid solution (PAA-1). The viscosity in the temperature of 25 degreeC of the obtained polyamic-acid solution was 881 mPa * s. Moreover, the molecular weight of this polyamic acid was Mn = 16766 and Mw = 59104.

(Comparative Synthesis Example 2)

4.27 g (20.0 mmol) of DA-1 was taken to the 100 mL four-necked flask with a stirring apparatus and the nitrogen introduction tube, 66.4g of NMP was added, and it stirred and sent out nitrogen and dissolved. While stirring the diamine solution, 2.63 g (13.4 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1.30 g (5.96 mmol) of pyromellitic dianhydride were added, and the solid content concentration NMP was added so that it might be 10 mass%, and it stirred at room temperature for 24 hours, and obtained the polyamic-acid solution (PAA-2). The viscosity in the temperature of 25 degreeC of the obtained polyamic-acid solution was 153 mPa * s. Moreover, the molecular weight of this polyamic acid was Mn = 13227 and Mw = 38432.

(Comparative Synthesis Example 3)

3.15 g (8.02 mmol) of DA-3 were added to the 100 ml four-necked flask with a stirrer and the nitrogen inlet tube, 37.6 g of NMP was added, and it stirred and sent out nitrogen and dissolved. While stirring this diamine solution, 0.972 g (4.96 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 0.526 g (2.41 mmol) of pyromellitic dianhydride are added, and solid content concentration further NMP was added so that it might be 10 mass%, and it stirred at room temperature for 24 hours, and obtained the polyamic-acid solution (PAA-3). The viscosity in the temperature of 25 degreeC of the obtained polyamic-acid solution was 2045 mPa * s. Moreover, the molecular weight of this polyamic acid was Mn = 16418 and Mw = 56595.

(Example 1)

A stirrer was put into a 50 ml Erlenmeyer flask, 5.52 g of polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 was added, 3.45 g of NMP and 2.22 g of BCS were added, followed by stirring with a magnetic stirrer for 30 minutes to give a liquid crystal. An aligning agent (A-1) was obtained.

(Example 2)

The stirrer was put into a 50 mL Erlenmeyer flask, 5.12g of polyamic acid ester solutions (PAE-2) obtained by the synthesis example 2 were added, 3.08g of NMP and 2.07g of BCS were added, and it stirred for 30 minutes with a magnetic stirrer, and liquid crystal An aligning agent (A-2) was obtained.

(Example 3)

A stirrer was put into a 50 ml Erlenmeyer flask, 4.04 g of polyamic acid ester solution (PAE-3) obtained in Synthesis Example 3 was taken, 4.08 g of NMP and 2.03 g of BCS were added, followed by stirring with a magnetic stirrer for 30 minutes to give a liquid crystal. An aligning agent (A-3) was obtained.

(Example 4)

A stirrer was put into a 50 ml Erlenmeyer flask, 4.99 g of the polyamic acid ester solution (PAE-4) obtained in the synthesis example 4 was taken, 3.00 g of NMP and 2.02 g of BCS were added, and it stirred for 30 minutes with a magnetic stirrer, and liquid crystal An aligning agent (A-4) was obtained.

(Example 5)

A stirrer was put into a 50 ml Erlenmeyer flask, 5.33 g of polyamic acid ester solution (PAE-5) obtained in Synthesis Example 5 was taken, 3.26 g of NMP and 2.30 g of BCS were added, followed by stirring with a magnetic stirrer for 30 minutes to give a liquid crystal. An aligning agent (A-5) was obtained.

(Comparative Example 1)

The stirrer was put into a 50 ml Erlenmeyer flask, 4.87g of polyamic-acid solutions (PAA-1) obtained by the comparative synthesis example 1 were added, 2.97g of NMP and 1.98g of BCS were added, and it stirred for 30 minutes with a magnetic stirrer, and liquid crystal An aligning agent (B-1) was obtained.

(Comparative Example 2)

The stirrer was put into a 50 ml Erlenmeyer flask, 5.22g of polyamic-acid solutions (PAA-2) obtained by the comparative synthesis example 2 were added, 3.15g of NMP and 2.18g of BCS were added, and it stirred for 30 minutes with a magnetic stirrer, and liquid crystal An aligning agent (B-2) was obtained.

(Comparative Example 3)

The stirrer was put into a 50 ml Erlenmeyer flask, 4.37g of polyamic-acid solutions (PAA-3) obtained by the comparative synthesis example 3 were added, 4.38g of NMP and 2.21g of BCS were added, and it stirred for 30 minutes with a magnetic stirrer, and liquid crystal An aligning agent (B-3) was obtained.

(Example 6)

After filtering the liquid crystal aligning agent (A-1) obtained in Example 1 with a 1.0 micrometer filter, it apply | coated to a quartz substrate by spin-coat application, and after drying for 5 minutes on an 80 degreeC hotplate, hot air of 230 degreeC It baked for 30 minutes in the circulation oven, and formed the coating film of 100 nm in film thickness. The transmittance | permeability of the obtained coating film was measured using the ultraviolet visible spectrophotometer (UV-3100PC) by Shimadzu Corporation, and the average value of the transmittance | permeability of 360 nm-800 nm was computed. As a result, the transmittance | permeability of the obtained membrane was 95.14%. The calculated transmittance is shown in Table 1.

(Example 7)

The transmittance | permeability of a film | membrane was measured by the method similar to Example 6 except having used the liquid crystal aligning agent (A-2) obtained in Example 2. The transmittance | permeability of the obtained membrane was 93.35%.

(Example 8)

The transmittance | permeability of a film | membrane was measured by the method similar to Example 6 except having used the liquid crystal aligning agent (A-3) obtained in Example 3. The transmittance | permeability of the obtained membrane was 92.74%.

(Example 9)

The transmittance | permeability of a film | membrane was measured by the method similar to Example 6 except having used the liquid crystal aligning agent (A-4) obtained in Example 4. The transmittance | permeability of the obtained membrane was 96.17%.

(Example 10)

The transmittance | permeability of a film | membrane was measured by the method similar to Example 6 except having used the liquid crystal aligning agent (A-5) obtained in Example 5. The transmittance | permeability of the obtained membrane was 95.35%.

(Comparative Example 4)

The transmittance | permeability of a film | membrane was measured by the method similar to Example 6 except having used the liquid crystal aligning agent (B-1) obtained by the comparative example 1. The transmittance | permeability of the obtained membrane was 89.58%.

(Comparative Example 5)

The transmittance of the film was measured in the same manner as in Example 6 except that the liquid crystal aligning agent (B-2) obtained in Comparative Example 2 was used. The transmittance of the obtained membrane was 91.35%.

(Comparative Example 6)

The transmittance of the film was measured in the same manner as in Example 6 except that the liquid crystal aligning agent (B-3) obtained in Comparative Example 3 was used. The transmittance | permeability of the obtained membrane was 88.56%.

(Example 11)

After filtering the liquid crystal aligning agent (A-1) obtained in Example 1 with a 1.0 micrometer filter, the ITO electrode of film thickness 50nm in a 1st layer is used as an insulating film in a 2nd layer on the glass substrate on the 1st layer. As the third layer, an FFS (fringe field switching) driving electrode is formed having a comb-shaped ITO electrode (electrode width: 3 m, electrode gap: 6 m, electrode height: 50 nm) as the third layer. It applied to the glass substrate which has become by spin coat application. After drying for 5 minutes on a 80 degreeC hotplate, baking was performed for 30 minutes by the 230 degreeC hot air circulation type oven, and the coating film of 100 nm of film thickness was formed. The rubbing process was performed to this coating film surface on condition of roller rotation speed 1000rpm, stage movement speed 20mm / s, and rubbing cloth indentation pressure of 0.4mm, and the board | substrate with a liquid crystal aligning film was obtained. Moreover, the coating film was similarly formed in the glass substrate which has a columnar spacer with a height of 4 micrometers in which an electrode is not formed as an opposing board | substrate, and the orientation process was performed.

Said two board | substrates are set as one set, the sealing compound is printed on a board | substrate, and the other one board | substrate is bonded so that a liquid crystal aligning film surface may face, and an orientation direction may be 0 degrees, and the sealing compound is hardened To make an empty cell. Liquid crystal MLC-2041 (made by Merck Co., Ltd.) was injected into this empty cell by the pressure reduction injection method, the injection hole was sealed, and the FFS drive liquid crystal cell was obtained. About this FFS drive liquid crystal cell, when the charge relaxation characteristic was evaluated by the following method, (DELTA) T in 0 minutes of AC drive was 47%, and (DELTA) T in 5 minutes of AC drive was 0%.

[Charge relaxation characteristics]

The FFS driving liquid crystal cell was placed on a light source, and the VT characteristic (voltage-transmittance characteristic) was measured at a temperature of 45 ° C., and then the transmittance (Ta) of the liquid crystal cell in the state where a rectangular wave of ± 1.5 V / 60 Hz was applied. ) Was measured. Thereafter, a rectangular wave of ± 1.5 V / 60 Hz was applied for 10 minutes at a temperature of 45 ° C., and then DC 2 V was superimposed and driven for 120 minutes. The transmittance (Tb) of the liquid crystal cell when the DC voltage was cut off and driven again for only 0 minutes and 5 minutes only with a rectangular wave of ± 1.5 V / 60 Hz was measured, respectively, and the transmittance (Tb) and initial transmittance at each time were measured. The difference in transmittance caused by the voltage remaining in the liquid crystal display element was calculated from the difference ΔT in (Ta).

(Example 12)

Except having used the liquid crystal aligning agent (A-2) obtained in Example 2, the FFS drive liquid crystal cell was produced and the charge relaxation characteristic was evaluated by the method similar to Example 11, As a result, (DELTA) T in 0 minutes of alternating current drive is ΔT in 46% and 5 minutes of AC drive was 0%.

(Example 13)

Except having used the liquid crystal aligning agent (A-3) obtained in Example 3, the FFS drive liquid crystal cell was produced and the charge relaxation characteristic was evaluated by the method similar to Example 11, As a result, (DELTA) T in 0 minutes of alternating current drive is ΔT in 46% and 5 minutes of AC drive was 0%.

(Example 14)

Except having used the liquid crystal aligning agent (A-4) obtained in Example 4, the FFS drive liquid crystal cell was produced and the charge relaxation characteristic was evaluated by the method similar to Example 11, As a result, (DELTA) T in 0 minutes of alternating current drive is ΔT in 46% and 5 minutes of AC drive was 0%.

(Example 15)

Except having used the liquid crystal aligning agent (A-5) obtained in Example 5, the FFS drive liquid crystal cell was produced and the charge relaxation characteristic was evaluated by the method similar to Example 11, As a result, (DELTA) T in 0 minutes of alternating current drive is ΔT in 46% and 5 minutes of AC drive was 0%.

(Comparative Example 7)

Except having used the liquid crystal aligning agent (B-1) obtained by the comparative example 1, the FFS drive liquid crystal cell was produced by the method similar to Example 11. As a result of evaluating the same charge relaxation characteristic as Example 11 about this FFS drive liquid crystal cell, (DELTA) T in 0 minutes of AC drive was 46%, and (DELTA) T in 5 minutes of AC drive was 0%.

Thus, the liquid crystal aligning film of Examples 6-10 obtained from liquid crystal aligning agent A-1 to A-5 containing the polyamic acid ester which has a repeating unit represented by Formula (1), and the liquid crystal aligning film of Comparative Examples 4-6 and In comparison, the transmittance was remarkably high. Moreover, the liquid crystal display element provided with the liquid crystal aligning film obtained from liquid crystal aligning agents A-1-A-5 was quick also the relaxation of the residual electric charge accumulated by the direct current voltage.

Industrial availability

The liquid crystal aligning agent of this invention has characteristics, such as a small relaxation | restoration when DC voltage is applied and / or quick relaxation of the accumulated residual charge by DC voltage, and the liquid crystal aligning film with high transmittance | permeability of the film obtained is obtained. . As a result, it is widely useful for TN (Twisted Nematic) elements, STN (Super Twisted Nematic) elements, TFT liquid crystal elements, and furthermore, vertically aligned liquid crystal display elements.

Claims

Polyamic acid ester which has a repeating unit represented by following formula (1), and an organic solvent are contained, The liquid crystal aligning agent characterized by the above-mentioned.
[Chemical Formula 1]

The method according to claim 1,
Y ₁ in formula (1) It is a divalent organic group containing at least 1 type of structure chosen from the group which consists of an amino group, an imino group, and a nitrogen-containing heterocyclic ring, The liquid crystal aligning agent characterized by the above-mentioned.

3. The method according to claim 1 or 2,
Y ₁ The ratio of the repeating unit represented by the said Formula (1) which is a divalent organic group containing at least 1 sort (s) of structure chosen from the group which consists of an amino group, an imino group, and a nitrogen-containing heterocyclic ring is 40 with respect to 1 mol of all structural units. It is-100 mol%, The liquid crystal aligning agent characterized by the above-mentioned.

4. The method according to any one of claims 1 to 3,
Y ₁ It is at least 1 sort (s) chosen from the group which consists of divalent organic groups which have a nitrogen atom represented by following formula (YD-1) (YD-5)-The liquid crystal aligning agent characterized by the above-mentioned.
(2)

(In formula (YD-1), A <_11> is a C3-C15 trivalent nitrogen-containing heterocycle, Z <_1> is a hydrogen atom or a C1-C20 monovalent hydrocarbon group which may have a substituent. in the formula (YD-2), W ₁ is a trivalent hydrocarbon group having a carbon number of 1 ~ 10, a ₁₂ are each two hydrogen of also a monovalent organic group having a carbon number of 3-15 having a nitrogen heterocyclic ring, or an amino group Independently a di-substituted amino group substituted with an aliphatic group having 1 to 6. In Formula (YD-3), W ₂ Is the carbon number of 6-15, and a divalent organic group having one or two benzene rings, W ₃ Is an alkylene group or a biphenylene group having a carbon number of ₂ ~ 5, Z 2 Is a hydrogen atom, a C1-C5 alkyl group, or a benzene ring, and a is an integer of 0-1. In Formula (YD-4), A ₁₃ is a divalent nitrogen-containing heterocyclic ring having 3 to 15 carbon atoms. In the formula (YD-5), A ₁₄ is a divalent nitrogen-containing heterocyclic ring having a carbon number of 3 ~ 15, W ₅ Is an alkylene group having 2 to 5 carbon atoms.)

5. The method according to any one of claims 1 to 4,
A nitrogen-containing heterocyclic ring having 3 to 15 carbon atoms of A ₁₁ , A ₁₂ , A ₁₃ , and A ₁₄ described in Formulas (YD-1), (YD-2), (YD-4) and (YD-5), At least one ring selected from the group consisting of pyrrolidine, pyrrole, imidazole, pyrazole, oxazole, thiazole, piperidine, piperazine, pyridine, pyrazine, indole, benzimidazole, quinoline, isoquinoline It is a liquid crystal aligning agent characterized by the above-mentioned.

6. The method according to any one of claims 1 to 5,
Y ₁ in formula (1) This is at least 1 sort (s) chosen from the group which consists of a divalent organic group which has the nitrogen atom represented by following formula (YD-6)-(YD-23), The liquid crystal aligning agent characterized by the above-mentioned.
(3)

(M and n are integers of 1-11 in a formula (YD-14), m + n is an integer of 2-12, h is an integer of 1-3 in a formula (YD-19), a formula J is an integer of 0-3 in (YD-16) and (YD-23).)

7. The method according to any one of claims 1 to 6,
X ₁ in formula (1) It is at least 1 sort (s) chosen from the group which consists of a structure represented by this formula, The liquid crystal aligning agent characterized by the above-mentioned.
[Chemical Formula 4]

The liquid crystal aligning film obtained by apply | coating and baking the liquid crystal aligning agent in any one of Claims 1-7.

It has the liquid crystal aligning film of Claim 8, The liquid crystal display element characterized by the above-mentioned.