JPWO2018155674A1 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display device - Google Patents

Abstract

The present invention provides a polyamic acid obtained by using a tetracarboxylic dianhydride component and a diamine component containing a diamine represented by the following formula (1), and at least one kind selected from imidized polymers of the polyamic acid. At least one selected from a polyamic acid obtained by using the polymer (A), a tetracarboxylic dianhydride component and a diamine component containing a diamine represented by the following formula (2), and an imidized polymer of the polyamic acid. The present invention relates to a liquid crystal aligning agent containing one kind of polymer (B). According to the present invention, it is possible to provide a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element which are excellent in voltage holding ratio, quickly relax stored charges, and can provide a liquid crystal aligning film having good stability of liquid crystal alignment. it can. In the formula (1), X represents-(CH2) n-, and n is a natural number of 8 or 9. In the formula (2), Y1 is a divalent organic group having an amino group or the like, and B1 and B2 are each independently a hydrogen atom or the like.

Description

  The present invention relates to a novel liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display device using the same.

  Liquid crystal display devices are widely used as display units for personal computers, mobile phones, smartphones, televisions, and the like. The liquid crystal display element includes, for example, a liquid crystal layer sandwiched between an element substrate and a color filter substrate, a pixel electrode and a common electrode for applying an electric field to the liquid crystal layer, an alignment film for controlling the alignment of liquid crystal molecules in the liquid crystal layer, A thin film transistor (TFT) for switching an electric signal supplied to the pixel electrode is provided. As a driving method of the liquid crystal molecules, a vertical electric field method such as a TN method and a VA method, and a horizontal electric field method such as an IPS method and an FFS method are known. The horizontal electric field method in which an electrode is formed on only one side of the substrate and an electric field is applied in a direction parallel to the substrate is wider than the conventional vertical electric field method in which a voltage is applied to electrodes formed on upper and lower substrates to drive liquid crystal. It is known as a liquid crystal display device having viewing angle characteristics and capable of high-quality display.

  Although the horizontal electric field type liquid crystal cell is excellent in viewing angle characteristics, since the electrode portion formed in the substrate is small, if the voltage holding ratio is low, a sufficient voltage is not applied to the liquid crystal, and the display contrast is reduced. In addition, when the stability of the liquid crystal alignment is low, the liquid crystal does not return to the initial state when the liquid crystal is driven for a long time, which causes a decrease in contrast and an afterimage. Therefore, the stability of the liquid crystal alignment is important. Furthermore, static electricity is easily accumulated in the liquid crystal cell, and charges are also accumulated in the liquid crystal cell by application of a positive / negative asymmetrical voltage generated by driving, and these accumulated charges affect display as disturbance of liquid crystal alignment or afterimage. In addition, the display quality of the liquid crystal element is significantly reduced. Also, charge is accumulated by irradiating the liquid crystal cell with the backlight light immediately after driving, which causes problems such as generation of an afterimage even in a short drive, and a change in the size of flicker during driving. Will happen.

  Patent Literature 1 includes a specific diamine and an aliphatic tetracarboxylic acid derivative as a liquid crystal aligning agent having excellent voltage holding ratio and reduced charge accumulation when used in such a lateral electric field type liquid crystal display device. A liquid crystal aligning agent is disclosed. Further, as a method of shortening the time until the afterimage disappears, an alignment film having a low volume resistivity as described in Patent Document 2 or a volume resistivity changed by a backlight of a liquid crystal display element as described in Patent Document 3 is known. A method using an alignment film that is difficult to perform has been proposed. However, the characteristics required for the liquid crystal alignment film are becoming stricter as the performance of the liquid crystal display element is improved, and it is difficult for these conventional techniques to sufficiently satisfy all the required characteristics.

International Publication WO2004 / 021076 pamphlet International Publication WO2004 / 053583 Pamphlet International Publication WO2013 / 008822 pamphlet

  The present invention provides a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element which are capable of obtaining a liquid crystal aligning film which is excellent in voltage holding ratio, has a quick relaxation of accumulated charge, and has good stability of liquid crystal alignment. Make it an issue.

  The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that various characteristics can be simultaneously improved by introducing a specific structure into a polymer contained in a liquid crystal aligning agent. Completed the invention. The present invention is based on such knowledge, and has the following gist.

<1> At least one type of polyamic acid obtained from a polyamic acid obtained using a tetracarboxylic dianhydride component and a diamine component containing a diamine represented by the following formula (1) and an imidized polymer of the polyamic acid: Merging (A),
At least one polymer (B) selected from a polyamic acid obtained by using a tetracarboxylic dianhydride component and a diamine component containing a diamine represented by the following formula (2) and an imidized polymer of the polyamic acid: ).

In formula (1), X - _(CH 2) n- and represents, n represents - (CH ₂₎ - is 8 or a natural number of 9 indicating the number of, any - (CH ₂₎ - each independently , -O-, -S-, -COO-, -OCO-, -CONH- and -NHCO-, these groups may be replaced under non-adjacent conditions, and R ₁ and R ₂ Are each independently a monovalent organic group, and p1 and p2 are each independently an integer of 0 to 4.

In the formula (2), Y ₁ is 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 heterocyclic ring, and B ₁ and B ₂ are each independently A hydrogen atom or an alkyl group, alkenyl group, or alkynyl group having 1 to 10 carbon atoms which may have a substituent.

<2> The liquid crystal alignment agent according to <1>, wherein Y ₁ in the formula (2) is at least one selected from the structures of the following formulas (YD-1) to (YD-5).

(In the formula (YD-1), A ₁ is a nitrogen-containing heterocycle having 3 to 15 carbon atoms, and Z ₁ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. In the formula (YD-2), W ₁ is a hydrocarbon group having 1 to 10 carbon atoms, A ₂ is a monovalent organic group having 3 to 15 carbon atoms having a nitrogen atom-containing heterocyclic ring, or It is a disubstituted amino group substituted with an aliphatic group having 1 to 6. In the formula (YD-3), W ₂ is a divalent having 6 to 15 carbon atoms and having 1 to 2 benzene rings. An organic group, W ₃ is a C 2 to C 18 divalent organic group containing a C 2 to C 5 alkylene or biphenylene or nitrogen-containing heterocycle, Z ₂ is a hydrogen atom, a C 1 to C 5 And a is an integer of 0 to 1. In the formula (YD-4), A ₃ is a nitrogen-containing heterocycle having ₃ to 15 carbon atoms, In the formula (YD-5), A ₄ is a nitrogen-containing heterocycle having 3 to 15 carbon atoms, and W ₅ is a C 2 to ₅ carbon atom. Is alkylene.)

<3> A ₁ , A ₂ , A ₃ , and A _{4 in} formulas (YD-1), (YD-2), (YD-4), and (YD-5) are pyrrolidine, pyrrole, and imidazole. <1> or <2>, which is at least one selected from the group consisting of, pyrazole, oxazole, thiazole, piperidine, piperazine, pyridine, pyrazine, indole, benzimidazole, quinoline, isoquinoline, and carbazole. .

<4> The above <1>, wherein Y ₁ in the formula (2) is at least one selected from the group consisting of divalent organic groups having the structures of the following formulas (YD-6) to (YD-22). Liquid crystal aligning agent of any one of <3>.

  (In the formula (YD-17), h is an integer of 1 to 3, and in the formulas (YD-14), (YD-21), and (YD-22), j is an integer of 0 to 3.)

<5> A group in which Y ₁ in the formula (2) is a divalent organic group having the structure of the above formulas (YD-14), (YD-18), (YD-21), and (YD-22). The liquid crystal aligning agent according to any one of the above <1> to <4>, which is at least one type selected from the group consisting of:

<6> A liquid crystal alignment film obtained by applying and firing the liquid crystal alignment agent according to any one of <1> to <5>.

<7> A liquid crystal display device comprising the liquid crystal alignment film according to <6>.

The use of the liquid crystal alignment agent of the present invention provides a liquid crystal alignment film having excellent voltage holding ratio, quick relaxation of accumulated charge, good stability of liquid crystal alignment, and a liquid crystal display element having excellent display characteristics.
Although it is not clear why the above-mentioned problems can be solved by the present invention, it is generally considered as follows.
The structure (2) of the polymer contained in the liquid crystal alignment agent of the present invention has a conjugated structure. Thereby, for example, the movement of charges can be promoted in the liquid crystal alignment film, and the relaxation of accumulated charges can be promoted.

The liquid crystal aligning agent of the present invention is a composition used for forming a liquid crystal alignment film, and has a specific polymer (A) obtained from the diamine represented by the above formula (1) and a structure represented by the above formula (2). And a liquid crystal aligning agent containing a specific polymer (B) obtained from a diamine having the following formula:
That is, in other words, the present invention relates to a polymer composition having a liquid crystal orientation, including the characteristic polymer (A) and the specific polymer (B).

  The content of the specific polymer (A) and the specific polymer (B) is 5 to 90% by weight based on the total amount of the specific polymer (A) and the specific polymer (B). And more preferably 10 to 50% by weight. That is, the specific polymer (B) is 95 to 10% by weight, more preferably 90 to 50% by weight, based on the total amount of the specific polymer (A) and the specific polymer (B). When the specific polymer (A) is too small, the stability of the liquid crystal alignment is deteriorated, and when the specific polymer (B) is too small, the relaxation property of accumulated charge is deteriorated. The specific polymer (A) and the specific polymer (B) contained in the liquid crystal aligning agent of the present invention may each be one type or two or more types.

<Polymer of component (A)>
The polymer of the present invention is a polymer obtained from a diamine component containing a diamine represented by the above formula (1) and an acid dianhydride component containing a tetracarboxylic dianhydride. Specific examples include polyamic acid, polyamic acid ester, polyimide, polyurea, and polyamide. From the viewpoint of use as a liquid crystal aligning agent, a polyimide precursor containing a structural unit represented by the following formula (3): And at least one selected from polyimides, which are imidates thereof. In the heating step after the irradiation of polarized light, a polyimide precursor is more preferable in that the polymer is re-oriented in a higher order due to a large number of free rotation sites in the polymer.

In the above formula (3), X ₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, Y ₁₁ is a divalent organic group derived from a diamine of the formula (1), and R ₁₁ is a hydrogen atom Or it is a C1-C5 alkyl group. R ₁₁ is preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom, from the viewpoint of imidization by heating.

<Diamine having specific structure>
The liquid crystal aligning agent of the present invention is selected from a polyamic acid obtained by using a tetracarboxylic dianhydride component and a diamine component containing a diamine represented by the following formula (1) and an imidized polymer of the polyamic acid. Polyamic acid obtained using at least one kind of polymer (A), a tetracarboxylic dianhydride component and a diamine component containing a diamine represented by the following formula (2), and an imidized polymer of the polyamic acid It is a liquid crystal aligning agent containing at least one kind of polymer (B) selected from the group consisting of: and an organic solvent.

(In the formula (1), X is - _(CH 2) n-a represents, n represents - (CH ₂₎ - is 8 or a natural number of 9 indicating the number of, any - (CH ₂₎ - are each independently a, -O -, - S -, - COO -, - OCO -, - CONH- and a group selected from -NHCO-, may be replaced by the conditions in which these groups are not adjacent, _{R 1} and R ₂ is independently a monovalent organic group, and p1 and p2 are each independently an integer of 0 to 4.)

  The monovalent organic group here includes an alkyl group, an alkenyl group, an alkoxy group, a fluoroalkyl group, a fluoroalkenyl group, or a fluoroalkoxy group having 1 to 10, preferably 1 to 3 carbon atoms. Of these, a methyl group is preferred as the monovalent organic group.

  In addition, when the total number of carbon atoms, oxygen atoms, sulfur atoms, and nitrogen atoms related to the length of the main chain is an even number, the linearity of the obtained polymer is increased. In a heating step after rubbing or irradiation with polarized ultraviolet light, re-alignment in a higher order is preferable because a liquid crystal alignment film having high alignment control ability can be obtained. The total number of carbon atoms, oxygen atoms, sulfur atoms, and nitrogen atoms related to the length of the main chain is defined as 1 per methylene in the main chain and 1 per ether bond. , The number per sulfide bond is 1, the number per ester bond is 2, and the number per amide bond is 2.

Any — (CH ₂ ) — in X is any one of —O—, —S—, —COO—, and —OCO— in that the weaker hydrogen bonding force causes higher order reorientation. It is preferably replaced, particularly preferably -O-.

p1 and p2 are preferably 0 from the viewpoint that phenyl groups are likely to overlap with each other due to little steric hindrance, and the molecules are reoriented in a higher order.

Diamines of the formula (1) - In (CH 2) _n-, when n is 8 or more, when the liquid crystal aligning agent and the polymer (B) were blended and subjected coated on the substrate, high alignment control force The polymer (A) has a high transferability to the upper layer, that is, the interface not on the substrate side, and thus contributes to the improvement of the orientation. When n is 10 or more, the alignment regulating force of the polymer (A) itself is greatly reduced. Therefore, unless n is 8 or 9, the effect of the present invention cannot be obtained. Specific examples of these diamines include the following, but are not limited thereto.

  Here, when r is 6 or t is 2 or 4 in the above formula, as a result, the linearity of the obtained polymer is increased, so that the polymer is reoriented in a higher order in the heating step after the irradiation of polarized light. Thus, a liquid crystal alignment film having high alignment control ability can be obtained.

<Tetracarboxylic dianhydride>
X ₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and its structure is not particularly limited. Further, X ₁ of the polyimide precursor is applied of solubility and liquid crystal aligning agent to the solvent of the polymer liquid crystal orientation in the case where the liquid crystal alignment film, the voltage holding ratio, such as the accumulated charge, is required It is appropriately selected according to the degree of the characteristic, and one kind may be used in the same polymer, or two or more kinds may be mixed.

If Specific examples of X ₁ dare shown, it is published in paragraph 13 to 14, wherein the WO 2015/119168, such as the structure of formula (X-1) ~ (X -46) are mentioned.

Below, shows the structure of a preferred X _1, the present invention is not limited thereto.

  Among these, (A-1) and (A-2) are preferable from the viewpoints of photoreactivity, liquid crystal orientation, and voltage holding ratio.

<Polymer (other structural units)>
The polyimide precursor containing the structural unit represented by the formula (3) is at least selected from a structural unit represented by the following formula (4) and a polyimide which is an imidated product thereof, as long as the effects of the present invention are not impaired. One type may be included.

In the formula (4), X ₂ is a tetravalent organic group derived from a tetracarboxylic acid derivative, Y ₁₂ is a divalent organic group derived from a diamine, and R ₁₂ is R of the above formula (3). ₁₁ is the same definition as _{in, R 22} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Further, it is preferable that at least one of the two R ₂₂ is a hydrogen atom.

Examples of X ₂ include the structures of formulas (X-1) to (X-46) described in paragraphs 13 to 14 of International Publication WO 2015/119168, and the above (A-1) To (A-21).

Y ₁₂ is a divalent organic group derived from a diamine, and its structure is not particularly limited. Further, Y ₁₂ is depending on the degree of coating of the solubility and liquid crystal alignment agent in the solvent of the polymer liquid crystal orientation in the case where the liquid crystal alignment film, the voltage holding ratio, such stored charge, is required properties One kind may be selected appropriately in the same polymer, and two or more kinds may be mixed in the same polymer.

If dare Specific examples of Y _12, the structure of the formulas listed in item 4 of WO 2015/119168 (2), and is published in 12 paragraphs 8 wherein the formula (Y-1) ~ (Y-97), the structures of (Y-101) to (Y-118); divalent organic compounds described in item 6 of WO2013 / 08906, wherein two amino groups are removed from formula (2). A divalent organic group obtained by removing two amino groups from the formula (1) described in section 8 of WO 2015/122413; a formula (3) described in section 8 of WO 2015/060360 A divalent organic group obtained by removing two amino groups from the formula (1) described in item 8 of JP-A-2012-173514; a formula described in item 9 of WO 2010-0550523 (A) to (F) in which two amino groups are removed from divalent Organic group, and the like.

Preferred examples of the structure of Y ₁₂ include a structure represented by the following formula (5).

In the formula (5), R ³² is a single bond or a divalent organic group, and is preferably a single bond.
R ³³ is - _{(CH 2) n} - is a structure represented by. n is an integer of 2 to 10, preferably 3 to 7. Also, any -CH 2 _- ether conditions nonadjacent respectively, esters, amides, ureas, may be replaced by a carbamate linkage.
R ³⁴ is a single bond or a divalent organic group.
Any hydrogen atom on the benzene ring may be replaced by a monovalent organic group, and is preferably a fluorine atom or a methyl group.

  Specific examples of the structure represented by the formula (5) include, but are not limited to, the following structures.

  When the polyimide precursor containing the structural unit represented by the formula (3) simultaneously contains the structural unit represented by the formula (4), the structural unit represented by the formula (3) is represented by the formula (3) and the formula (3). It is preferably from 30 mol% to 100 mol%, more preferably from 50 mol% to 100 mol%, particularly preferably from 70 mol% to 100 mol%, based on the total of (4).

<Polymer of component (B)>
The component (B) used in the liquid crystal aligning agent of the present invention is a polyamic acid obtained using a tetracarboxylic dianhydride component and a diamine component containing a diamine represented by the above formula (2), and an imide of the polyamic acid. It is at least one kind of polymer selected from polymerized polymers.

<Tetracarboxylic dianhydride component>
Examples of the tetracarboxylic dianhydride used for producing the component (B) of the present invention include a tetracarboxylic dianhydride represented by the following formula (6).

In the formula, the _{X 3,} include structures selected from the described at the component (A) (A-1) ~ (A -21). In the production of the component (B), the tetracarboxylic dianhydride component used may be one type or two or more types.

<Diamine component>
The diamine component used for producing the liquid crystal alignment agent of the present invention contains the diamine of the above formula (2). In the formula (2), Y ₁ is 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 heterocyclic ring, and B _{1 and} B ₂ are each independently A hydrogen atom or an alkyl group, alkenyl group, or alkynyl group having 1 to 10 carbon atoms which may have a substituent.

Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, a hexyl group, an octyl group, a decyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the alkenyl group include those in which one or more CH—CH structures present in the above-mentioned alkyl group are replaced with a C ＝ C structure, and more specifically, a vinyl group, an allyl group, and a 1-propenyl group. , An isopropenyl group, a 2-butenyl group, a 1,3-butadienyl group, a 2-pentenyl group, a 2-hexenyl group, a cyclopropenyl group, a cyclopentenyl group, and a cyclohexenyl group. Examples of the alkynyl group include those in which one or more CH ₂ —CH ₂ structures present in the alkyl group are replaced with a C に C structure. More specifically, an ethynyl group, a 1-propynyl group, -Propynyl group and the like.

  The above alkyl group, alkenyl group, and alkynyl group may have a substituent as long as they have 1 to 10 carbon atoms as a whole, and may further form a ring structure by the substituent. Note that forming a ring structure with a substituent means that the substituents are combined with each other or the substituent and a part of the mother skeleton to form a ring structure.

  Examples of the substituent include a halogen group, a hydroxyl group, a thiol group, a nitro group, an aryl group, an organooxy group, an organothio group, an organosilyl group, an acyl group, an ester group, a thioester group, a phosphoric ester group, an amide group, and an alkyl group. Group, alkenyl group and alkynyl group.

Examples of the halogen group as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the aryl group as a substituent include a phenyl group. This aryl group may be further substituted with the other substituents described above.

  As the organooxy group as a substituent, a structure represented by OR can be shown. R may be the same or different, and examples thereof include the aforementioned alkyl group, alkenyl group, alkynyl group, and aryl group. These R may be further substituted by the aforementioned substituents. Specific examples of the alkyloxy group include a methoxy group, an ethoxy group, a propyloxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, and an octyloxy group.

  As the organothio group as a substituent, a structure represented by -SR can be shown. Examples of R include the above-described alkyl group, alkenyl group, alkynyl group, and aryl group. These R may be further substituted by the aforementioned substituents. Specific examples of the alkylthio group include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, an octylthio group, and the like.

As the organosilyl group as a substituent, a structure represented by -Si- (R) ₃ can be shown. R may be the same or different, and examples thereof include the aforementioned alkyl group, alkenyl group, alkynyl group, and aryl group. These R may be further substituted by the aforementioned substituents. Specific examples of the alkylsilyl group include a trimethylsilyl group, a triethylsilyl group, a tripropylsilyl group, a tributylsilyl group, a tripentylsilyl group, a trihexylsilyl group, a pentyldimethylsilyl group, and a hexyldimethylsilyl group.

  As the acyl group that is a substituent, a structure represented by —C (O) —R can be shown. Examples of R include the above-described alkyl group, alkenyl group, and aryl group. These R may be further substituted by the aforementioned substituents. Specific examples of the acyl group include a formyl group, an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a valeryl group, an isovaleryl group, and a benzoyl group.

  As the ester group which is a substituent, a structure represented by -C (O) OR or -OC (O) -R can be shown. Examples of R include the above-described alkyl group, alkenyl group, alkynyl group, and aryl group. These R may be further substituted by the aforementioned substituents.

  As the thioester group which is a substituent, a structure represented by -C (S) OR or -OC (S) -R can be shown. Examples of R include the above-described alkyl group, alkenyl group, alkynyl group, and aryl group. These R may be further substituted by the aforementioned substituents.

As the phosphate group as a substituent, a structure represented by -OP (O)-(OR) ₂ can be shown. R may be the same or different, and examples thereof include the aforementioned alkyl group, alkenyl group, alkynyl group, and aryl group. These R may be further substituted by the aforementioned substituents.

Examples of the amide group is a substituent, -C (O) NH _2, or, -C (O) NHR, -NHC (O) R, -C (O) N (R) 2, -NRC (O) R Can be shown. R may be the same or different, and examples thereof include the aforementioned alkyl group, alkenyl group, alkynyl group, and aryl group. These R may be further substituted by the aforementioned substituents.

As the aryl group which is a substituent, the same aryl groups as those described above can be exemplified. This aryl group may be further substituted with the other substituents described above.
Examples of the alkyl group as a substituent include the same alkyl groups as those described above. This alkyl group may be further substituted with the other substituents described above.
Examples of the alkenyl group as a substituent include the same alkenyl groups as those described above. This alkenyl group may be further substituted with the other substituents described above.
Examples of the alkynyl group as a substituent include the same alkynyl groups described above. This alkynyl group may be further substituted with the other substituents described above.

In general, when a bulky structure is introduced, the reactivity of the amino group and the liquid crystal alignment may be reduced. Therefore, as B ₁ and B ₂ , a hydrogen atom or a carbon atom having 1 substituent which may have a substituent is used. To 5 are more preferable, and a hydrogen atom, a methyl group or an ethyl group is particularly preferable.

The structure of Y ₁ in the formula (2) is not particularly limited as long as it has at least one kind of structure selected from the group consisting of an amino group, an imino group, and a nitrogen-containing heterocyclic ring. Absent. If the specific examples are given, at least one kind selected from the group consisting of an amino group, an imino group, and a nitrogen-containing heterocycle represented by the following formulas (YD-1) to (YD-5). And a divalent organic group having a structure.

In the formula (YD-1), A ₁ is a nitrogen-containing heterocycle having 3 to 15 carbon atoms, and Z ₁ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. is there.
In the formula (YD-2), W ₁ is a hydrocarbon group having 1 to 10 carbon atoms, and A ₂ is a monovalent organic group having 3 to 15 carbon atoms and having a nitrogen atom-containing heterocyclic ring, or 1 carbon atom. A di-substituted amino group substituted with an aliphatic group from 1 to 6.

In the formula (YD-3), W ₂ is a divalent organic group having 6 to 15 carbon atoms and having 1 to 2 benzene rings, and W ₃ is an alkylene or biphenylene having 2 to 5 carbon atoms or a nitrogen atom. A divalent organic group having 12 to 18 carbon atoms including a heterocyclic ring contained therein, Z ₂ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a benzene ring, and a is an integer of 0 to 1.

In the formula (YD-4), A ₃ is a nitrogen-containing heterocyclic ring having ₃ to 15 carbon atoms.
In the formula (YD-5), A ₄ is a nitrogen-containing heterocyclic ring having 3 to 15 carbon atoms, and W ₅ is an alkylene having 2 to ₅ carbon atoms.

A ₁ , A ₂ , A ₃ , and A _{4 in} the formulas (YD-1), (YD-2), (YD-4), and (YD-5), a nitrogen-containing heterocyclic ring having 3 to 15 carbon atoms. Is not particularly limited as long as it has a known structure. Among them, pyrrolidine, pyrrole, imidazole, pyrazole, oxazole, thiazole, piperidine, piperazine, pyridine, pyrazine, indole, benzimidazole, quinoline, isoquinoline, carbazole, and piperazine, piperidine, indole, benzimidazole, imidazole, carbazole, pyrrole And pyridine are more preferred.

Further, specific examples of Y ₂ in the formula (2) include a divalent organic group having a nitrogen atom represented by the following formulas (YD-6) to (YD-43). Can be suppressed and the stored charge can be relaxed quickly, so that the formulas (YD-14), (YD-18), (YD-19), (YD-20), (YD-21), and (YD-23) ) To (YD-30) and (YD-40) to (YD-43) are more preferable, and (YD-14), (YD-18), (YD-23), (YD-25), and (YD- 40) to (YD-43) are particularly preferred.

  In the formula (YD-17), h is an integer of 1 to 3, and in the formulas (YD-14), (YD-21) and (YD-22), j is an integer of 0 to 3.

  In the formulas (YD-25), (YD-26), (YD-29) and (YD-30), j is an integer of 0 to 3.

  In the formulas (YD-41), (YD-42) and (YD-43), j is an integer of 0 to 3.

  The ratio of the diamine represented by the formula (2) in the polyamic acid and the imidized polymer of the polyamic acid of the present invention is preferably 10 to 100 mol%, more preferably 30 to 100 mol%, based on 1 mol of the total diamine. -100 mol%, more preferably 50-100 mol%.

  The diamine represented by the formula (2) in the polyamic acid and the imidized polymer of the polyamic acid as the component (B) of the present invention may be used alone or in combination of two or more. The diamine represented by the formula (2) is preferably used in the above-mentioned preferable amount as a total.

The polyamic acid and the imidized polymer of the polyamic acid as the component (B) contained in the liquid crystal aligning agent of the present invention are represented by the following formula (7) in addition to the diamine represented by the above formula (2). Diamines may be used. Y ₂ in the following formula (7) is a divalent organic group, and its structure is not particularly limited, and two or more kinds may be mixed. The following (Y-1) to (Y-75) are given as specific examples.

  In the polyamic acid as the component (B) and the imidized polymer of the polyamic acid contained in the liquid crystal aligning agent of the present invention, if the proportion of the diamine represented by the formula (7) increases, the effect of the present invention may be impaired. It is not preferable because of its properties. Therefore, the proportion of the diamine represented by the formula (7) is preferably 0 to 90 mol%, more preferably 0 to 50 mol%, and still more preferably 0 to 20 mol%, based on 1 mol of the total diamine. .

<Production method of polyamic acid ester>
The polyamic acid ester which is a polyimide precursor used in the present invention can be synthesized by the following method (1), (2) or (3).

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

  As the esterifying agent, those which can be easily removed by purification are preferable, and N, N-dimethylformamide dimethyl acetal, N, N-dimethylformamide diethyl acetal, N, N-dimethylformamide dipropyl acetal, N, N-dimethylformamide Dineopentyl butyl acetal, N, N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p -Tolyltriazene, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride and the like. The addition amount of the esterifying agent is preferably 2 to 6 molar equivalents per 1 mol of the repeating unit of the polyamic acid.

  The solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone from the viewpoint of solubility of the polymer. These solvents may be used alone or in combination of two or more. Good. The concentration at the time of synthesis is preferably from 1 to 30% by mass, more preferably from 5 to 20% by mass, from the viewpoint that precipitation of the polymer hardly occurs and a high molecular weight product is easily obtained.

(2) When Synthesizing by Reaction of Tetracarboxylic Diester Dichloride and Diamine Polyamic acid ester can be synthesized from tetracarboxylic diester dichloride and diamine.

  Specifically, tetracarboxylic acid diester dichloride and diamine 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 4 hours It can be synthesized by reacting.

  As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable because the reaction proceeds gently. The amount of the base to be added is preferably 2 to 4 times the mol of the tetracarboxylic acid diester dichloride from the viewpoint of easy removal and easy production of a high molecular weight compound.

  The solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone from the solubility of the monomer and the polymer, and these may be used alone or in combination of two or more. The polymer concentration at the time of synthesis is preferably from 1 to 30% by mass, more preferably from 5 to 20% by mass, from the viewpoint that precipitation of the polymer hardly occurs and a high-molecular-weight product is easily obtained. Further, in order to prevent hydrolysis of the tetracarboxylic diester dichloride, the solvent used for the synthesis of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent outside air from being mixed in a nitrogen atmosphere.

(3) When synthesizing a polyamic acid ester from a tetracarboxylic diester and a diamine A polyamic acid ester can be synthesized by polycondensing a tetracarboxylic diester and a diamine.

Specifically, a tetracarboxylic diester and a diamine are reacted with a condensing agent, a base, and an organic solvent at 0 ° C to 150 ° C, preferably at 0 ° C to 100 ° C for 30 minutes to 24 hours, preferably 3 to 15 hours. It can be synthesized by reacting for a time.
The condensing agent includes triphenyl phosphite, dicyclohexylcarbodiimide, 1-

Ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N'-carbonyldiimidazole, dimethoxy-1,3,5-triazinylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethyluronium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N, N', N'-tetramethyluronium hexafluorophosphate, Diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate and the like can be used. The addition amount of the condensing agent is preferably 2 to 3 times the mol of the tetracarboxylic diester.

Tertiary amines such as pyridine and triethylamine can be used as the base. The amount of the base to be added is preferably 2 to 4 times the mol of the diamine component from the viewpoint of easy removal and high molecular weight.
In addition, in the above reaction, the reaction proceeds efficiently by adding a Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The addition amount of the Lewis acid is preferably from 0 to 1.0 times mol of the diamine component.

Among the above three methods for synthesizing polyamic acid esters, the method (1) or (2) is particularly preferable because a high molecular weight polyamic acid ester is obtained.
The solution of the polyamic acid ester obtained as described above can be poured into a poor solvent with good stirring to precipitate a polymer. Precipitation is performed several times, followed by washing with a poor solvent, followed by drying at room temperature or by heating to obtain a purified polyamic acid ester powder. The poor solvent is not particularly limited, and examples thereof include water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.

<Synthesis of polyamic acid>
When the specific polymer (A) or the specific polymer (B) is obtained by a reaction between a tetracarboxylic dianhydride and a diamine, the reaction is carried out by mixing the tetracarboxylic dianhydride with the diamine in an organic solvent. The method is simple.

  The organic solvent used in the above reaction is not particularly limited as long as the produced polyamic acid can be dissolved therein. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, Examples include N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, and the like. These may be used alone or as a mixture. Furthermore, even if the solvent does not dissolve the polyamic acid, it may be used by mixing with the above solvent as long as the generated polyamic acid does not precipitate. In addition, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the generated polyamic acid, it is preferable to use a dehydrated organic solvent as much as possible.

  As a method of mixing the tetracarboxylic dianhydride component and the diamine component in an organic solvent, a solution obtained by dispersing or dissolving the diamine component in the organic solvent is stirred, and the tetracarboxylic dianhydride component is directly mixed with the organic solvent. Dispersing or dissolving in a solvent and adding the dicarboxylic acid to the solution obtained by dispersing or dissolving the tetracarboxylic dianhydride component in the organic solvent, and adding the diamine component to the solution. Examples thereof include a method of alternately adding them, and any of these methods may be used in the present invention. When the tetracarboxylic dianhydride component or the diamine component is composed of a plurality of types of compounds, the plurality of types of components may be reacted in a state of being mixed in advance, or may be individually and sequentially reacted.

  The temperature at which the tetracarboxylic dianhydride component and the diamine component are reacted in an organic solvent is usually 0 to 150 ° C, preferably 5 to 100 ° C, more preferably 10 to 80 ° C. The higher the temperature, the sooner the polymerization reaction ends. However, if the temperature is too high, a high molecular weight polymer may not be obtained. The reaction can be carried out at any concentration, but if the concentration is too low, it becomes difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring is difficult. Therefore, the content is preferably 1 to 50% by weight, more preferably 5 to 30% by weight. The reaction may be performed at a high concentration in the initial stage, and then an organic solvent may be added.

  The molar ratio of the tetracarboxylic dianhydride component to the diamine component used in the polymerization reaction of the polyamic acid is preferably 1: 0.8 to 1.2. Further, the polyamic acid obtained by adding an excess of the diamine component may have a large coloring of the solution. Therefore, if the coloring of the solution is a concern, the ratio may be set to 1: 0.8 to 1. As in the ordinary polycondensation reaction, the molecular weight of the obtained polyamic acid increases as the molar ratio approaches 1: 1. If the molecular weight of the polyamic acid is too small, the strength of the coating film obtained therefrom may be insufficient.On the contrary, if the molecular weight of the polyamic acid is too large, the viscosity of the liquid crystal alignment treatment agent produced therefrom is high. Too much, and the workability during coating film formation and the uniformity of the coating film may be deteriorated. Therefore, the polyamic acid used in the liquid crystal aligning agent of the present invention preferably has a reduced viscosity (concentration: 0.5 dl / g, 30 ° C. in NMP) of 0.1 to 2.0, more preferably 0.2 to 1.5. is there.

  If the solvent used for the polymerization of the polyamic acid is not desired to be contained in the liquid crystal aligning agent of the present invention, or if unreacted monomer components or impurities are present in the reaction solution, the precipitate is recovered and purified. In this method, it is preferable that the polyamic acid solution is put into a stirring poor solvent and the precipitate is recovered. The poor solvent used for the precipitation and recovery of the polyamic acid is not particularly limited, and examples thereof include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene. The polyamic acid precipitated by being introduced into the poor solvent is recovered by filtration and washing, and then dried at normal temperature or under reduced pressure at normal temperature or under heat to obtain a powder. The operation of dissolving the powder in a good solvent and reprecipitating the same is repeated 2 to 10 times to purify the polyamic acid. When the impurities cannot be completely removed by a single precipitation recovery operation, this purification step is preferably performed. It is preferable to use three or more kinds of poor solvents such as alcohols, ketones, and hydrocarbons as the poor solvent in this case, because the purification efficiency is further improved.

<Production method of polyimide>
The polyimide used in the present invention can be produced by imidizing the above polyamic acid ester or polyamic acid. When a polyimide is produced from a polyamic acid ester, chemical imidization in which a basic catalyst is added to a polyamic acid ester solution or a polyamic acid solution obtained by dissolving a polyamic acid ester resin powder in an organic solvent is simple. Chemical imidization is preferable because the imidization reaction proceeds at a relatively low temperature, and the molecular weight of the polymer hardly decreases during the imidization process.

  When a polyimide is produced from a polyamic acid, chemical imidization in which a catalyst is added to a solution of the polyamic acid obtained by reacting a diamine component with a tetracarboxylic dianhydride is simple. Chemical imidization is preferred because the imidization reaction proceeds at a relatively low temperature, and the molecular weight of the polymer hardly decreases during the imidization process.

  Chemical imidization can be carried out by stirring the polymer to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride. As the organic solvent, the solvent used in the above-mentioned polymerization reaction can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine is preferable because it has an appropriate basicity for causing the reaction to proceed. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among them, acetic anhydride is preferred because purification after the reaction is easy.

  The temperature at which the imidization reaction is performed is -20 ° C to 140 ° C, preferably 0 ° C to 100 ° C, and the reaction time can be 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 times, preferably 2 to 20 times, the mole of the amic acid group, and the amount of the acid anhydride is 1 to 50 times, preferably 3 to 30 times the amic acid group. It is twice. The imidation ratio of the obtained polymer can be controlled by adjusting the amount of catalyst, temperature, and reaction time.

  In the solution after the imidation reaction of the polyamic acid ester or polyamic acid, since the added catalyst and the like remain, the obtained imidized polymer is recovered by the means described below and redissolved in an organic solvent. Thus, the liquid crystal alignment agent of the present invention is preferably used.

By pouring the polyimide solution obtained as described above into a poor solvent while stirring well, a polymer can be precipitated. Precipitation is performed several times, followed by washing with a poor solvent, followed by drying at room temperature or by heating to obtain a purified polyamic acid ester powder.
The poor solvent is not particularly limited, but examples thereof include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene.

  The molecular weight of the polyimide precursors (A) and (B) used in the present invention is preferably 2,000 to 500,000, more preferably 5,000 to 300,000 in terms of weight average molecular weight. Preferably, it is 10,000 to 100,000.

  Examples of the polyimide which is the component (A) and the component (B) used in the present invention include a polyimide obtained by ring-closing the above-mentioned polyimide precursor. In this polyimide, the ring-closure rate (also referred to as imidation rate) of the amide acid group does not necessarily need to be 100%, and can be arbitrarily adjusted according to the application and purpose.

<Liquid crystal aligning agent>
The liquid crystal alignment agent of the present invention is a composition used to form a liquid crystal alignment film, and comprises a specific polymer (A) having a structure represented by the above formula (1) and a structure represented by the above formula (2). And the specific polymer (A) and the specific polymer (B) contained in the liquid crystal aligning agent of the present invention, even if they are one kind each, There may be more than one type. Further, in addition to the specific polymer, other polymers, that is, a polymer having neither a divalent group represented by the formula (1) nor a divalent group represented by the formula (2) are contained. May be. Examples of such other polymers include polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene or its derivative, poly (styrene-phenylmaleimide) derivative, poly ( (Meth) acrylate and the like. When the liquid crystal aligning agent of the present invention contains another polymer, the ratio of the specific polymer to all polymer components is preferably 5% by mass or more, and an example thereof is 5 to 95% by mass.

  The liquid crystal alignment agent is used for producing a liquid crystal alignment film, and generally takes a form of a coating liquid from the viewpoint of forming a uniform thin film. The liquid crystal aligning agent of the present invention is also preferably a coating liquid containing the polymer component described above and an organic solvent that dissolves the polymer component. At that time, the concentration of the polymer in the liquid crystal alignment agent can be appropriately changed by setting the thickness of the coating film to be formed. The amount is preferably 1% by mass or more from the viewpoint of forming a uniform and defect-free coating film, and is preferably 10% by mass or less from the viewpoint of storage stability of the solution. A particularly preferred concentration of the polymer is 2 to 8% by mass.

  The organic solvent contained in the liquid crystal alignment agent is not particularly limited as long as the polymer component is uniformly dissolved. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, and 1,3-dimethyl. -2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone and the like. Among them, it is preferable to use N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone.

  In addition, the organic solvent contained in the liquid crystal aligning agent uses a mixed solvent that is used in combination with a solvent that improves the applicability and the surface smoothness of the coating film when applying the liquid crystal aligning agent in addition to the solvent described above. In general, such a mixed solvent is suitably used in the liquid crystal aligning agent of the present invention. Specific examples of the organic solvent used in combination are shown below, but the present invention 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- Dimethyl 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 Tyl 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-ethoxybutyl Acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl 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 Acetate, 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, methyl lactate, milk Ethyl ester, lactic acid n- propyl ester, lactate n- butyl ester, lactic acid isoamyl ester, the following formula [D-1] and the like solvents represented by ~ [D-3].

In the formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms; in the formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms; In the formula, D ³ represents an alkyl group having 1 to 4 carbon atoms.

  Among these, preferred combinations of solvents include N-methyl-2-pyrrolidone, γ-butyrolactone and 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 and γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone and 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-pyrrolidone Don, γ-butyrolactone, propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol, N-methyl-2-pyrrolidone, γ-butyrolactone and dipropylene glycol dimethyl ether, and the like can be mentioned. The type and content of such a solvent are appropriately selected according to the application apparatus, application conditions, application environment, and the like of the liquid crystal aligning agent.

  In addition, an additive such as a silane coupling agent may be added to the liquid crystal alignment agent of the present invention in order to improve the adhesion of the coating film to the substrate, or another resin component may be added. .

  Examples of the compound that improves the adhesiveness between the liquid crystal alignment film and the substrate include a functional silane-containing compound and an epoxy group-containing compound, such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-aminopropyltriethoxysilane. Glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2- (Aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl- 3-aminopropyltrimethoxy Silane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10 -Triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-amino Propyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3 -Aminopropyltrimethoxysilane, N Bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl Ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N , N ', N',-Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane or N, N, N ', N',-tetraglycidyl Etc. Le-4,4'-diaminodiphenylmethane and the like.

  Further, the following additives may be added to the liquid crystal alignment agent of the present invention in order to increase the mechanical strength of the film.

  These additives are preferably used in an amount of 0.1 to 30 parts by mass based on 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 exceeds 30 parts by mass, the orientation of the liquid crystal is reduced, so that the amount is more preferably 0.5 to 20 parts by mass.

<Liquid crystal alignment film>
The liquid crystal alignment film of the present invention is obtained from the liquid crystal alignment agent. As an example of a method for obtaining a liquid crystal alignment film from a liquid crystal alignment agent, a liquid crystal alignment agent in the form of a coating liquid is applied to a substrate, dried, and baked. And a method of performing an orientation treatment.

  The substrate on which the liquid crystal aligning agent is applied is not particularly limited as long as it is a substrate having high transparency. Along with a glass substrate and a silicon nitride substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate can also be used. At that time, it is preferable to use a substrate on which an ITO electrode or the like for driving the liquid crystal is formed in terms of simplification of the process. In a reflection type liquid crystal display device, an opaque object such as a silicon wafer can be used as long as only one substrate is used. In this case, a material that reflects light such as aluminum can be used for the electrode.

  The method for applying the liquid crystal alignment agent is not particularly limited, but industrially, screen printing, offset printing, flexographic printing, an inkjet method, and the like are generally used. Other coating methods include a dip method, a roll coater method, a slit coater method, a spinner method, a spray method and the like, and these may be used according to the purpose.

  After the liquid crystal aligning agent is applied on the substrate, the solvent is evaporated and baked by a heating means such as a hot plate, a thermal circulation oven, or an IR (infrared) oven. In the drying and baking steps after the application of the liquid crystal aligning agent, any temperature and time can be selected. Usually, in order to sufficiently remove the contained solvent, the conditions include firing at 50 to 120 ° C for 1 to 10 minutes, and then firing at 150 to 300 ° C for 5 to 120 minutes.

The thickness of the liquid crystal alignment film after firing is not particularly limited, but if it is too thin, the reliability of the liquid crystal display element may be reduced. Therefore, the thickness is preferably from 5 to 300 nm, more preferably from 10 to 200 nm.
INDUSTRIAL APPLICABILITY The liquid crystal alignment film of the present invention is suitable as a liquid crystal alignment film of a liquid crystal display device of an in-plane switching method such as an IPS method or an FFS method, and is particularly useful as a liquid crystal alignment film of a liquid crystal display device of an FFS method.

<Liquid crystal display device>
The liquid crystal display element of the present invention is obtained by obtaining a substrate with a liquid crystal alignment film obtained from the above liquid crystal alignment agent, then manufacturing a liquid crystal cell by a known method, and using the liquid crystal cell as an element.
As an example of a method for manufacturing a liquid crystal cell, a liquid crystal display element having a passive matrix structure will be described as an example. Note that an active matrix liquid crystal display element in which a switching element such as a TFT (Thin Film Transistor) is provided in each pixel portion forming an image display may be used.

Specifically, a transparent glass substrate is prepared, and a common electrode is provided on one substrate, and a segment electrode is provided on the other substrate. These electrodes can be, for example, ITO electrodes, and are patterned so that a desired image can be displayed. Next, an insulating film is provided on each substrate so as to cover the common electrode and the segment electrodes. The insulating film may be, for example, a film made of SiO ₂ —TiO ₂ formed by a sol-gel method. Next, a liquid crystal alignment film is formed on each substrate under the above conditions.

  Next, for example, an ultraviolet-curable sealing material was disposed at a predetermined position on one of the two substrates on which the liquid crystal alignment film was formed, and liquid crystal was disposed at predetermined predetermined positions on the liquid crystal alignment film surface. After that, the other substrate is bonded and pressed so that the liquid crystal alignment film faces the liquid crystal to spread the liquid crystal on the front surface of the liquid crystal alignment film, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealing material. Get the cell.

  Alternatively, as a step after forming a liquid crystal alignment film on a substrate, when a sealing material is arranged at a predetermined place on one of the substrates, an opening that can be filled with liquid crystal from the outside is provided, and the liquid crystal is formed. After bonding the substrates without disposing them, a liquid crystal material is injected into the liquid crystal cell through an opening provided in the sealing material, and then the opening is sealed with an adhesive to obtain a liquid crystal cell. The liquid crystal material may be injected by a vacuum injection method or a method utilizing a capillary phenomenon in the air.

  In any of the above methods, in order to secure a space for filling the liquid crystal material in the liquid crystal cell, a columnar projection is provided on one substrate, spacers are scattered on one substrate, or a sealing material is used. It is preferable to take measures such as mixing a spacer into the substrate or combining them.

Examples of the liquid crystal material include a nematic liquid crystal and a smectic liquid crystal. Among them, a nematic liquid crystal is preferable, and any of a positive liquid crystal material and a negative liquid crystal material may be used. Next, a polarizing plate is installed. Specifically, it is preferable to attach a pair of polarizing plates to surfaces of the two substrates opposite to the liquid crystal layer.
Note that the liquid crystal alignment film and the liquid crystal display element of the present invention are not limited to the above description as long as the liquid crystal alignment agent of the present invention is used, and may be manufactured by other known methods. good. The steps up to obtaining a liquid crystal display element from a liquid crystal aligning agent are disclosed in, for example, paragraphs 0074 to 1979 on page 17 of JP-A-2015-135393, and the like.

<Method of Manufacturing Substrate Having Liquid Crystal Alignment Film> and <Method of Manufacturing Liquid Crystal Display Element>
As an example of a method for manufacturing a substrate having a liquid crystal alignment film of the present invention, a method for manufacturing a liquid crystal alignment film for a lateral electric field drive type liquid crystal display element will be described below.
[I] At least one type of polyamic acid selected from a polyamic acid obtained by using a tetracarboxylic dianhydride component and a diamine component containing a diamine represented by the above formula (1), and an imidized polymer of the polyamic acid At least one selected from a polyamic acid obtained by using the union (A), a tetracarboxylic dianhydride component and a diamine component containing the diamine represented by the above formula (2), and an imidized polymer of the polyamic acid; Applying a liquid crystal aligning agent containing a polymer of the type (B) onto a substrate having a conductive film for driving a horizontal electric field, followed by drying to form a coating film;
[II] a step of irradiating the coating film obtained in [I] with polarized ultraviolet light; and [III] a step of heating the coating film obtained in [II];
Have
Through the above steps, a liquid crystal alignment film for a horizontal electric field drive type liquid crystal display element having an alignment control ability can be obtained, and a substrate having the liquid crystal alignment film can be obtained.

In addition, by preparing a second substrate in addition to the obtained substrate (first substrate), a lateral electric field driving type liquid crystal display element can be obtained.
As the second substrate, a substrate having no conductive film for driving a horizontal electric field is used instead of a substrate having a conductive film for driving a horizontal electric field, except that the above-described steps [I] to [III] ( Since a substrate having no conductive film is used, for convenience, in the present application, the steps [I ′] to [III ′] may be abbreviated) to provide a liquid crystal alignment film having an alignment control ability. Two substrates can be obtained.

The manufacturing method of the lateral electric field drive type liquid crystal display element is as follows.
[IV] a step of obtaining a liquid crystal display element by arranging the first and second substrates obtained above in such a manner that the liquid crystal alignment films of the first and second substrates face each other via the liquid crystal;
Have Thereby, a lateral electric field driving type liquid crystal display element can be obtained.

  Hereinafter, each of the steps [I] to [III] and [IV] of the production method of the present invention will be described.

<Step [I]>
In step [I], a polymer composition containing a photosensitive main-chain polymer and an organic solvent is applied to a substrate having a conductive film for driving a lateral electric field, and then dried to form a coating film. The photosensitive main chain type polymer in the present invention is the specific polymer (A).

<Board>
The substrate is not particularly limited, but when the liquid crystal display element to be manufactured is of a transmission type, it is preferable to use a substrate having high transparency. In that case, there is no particular limitation, and a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used.
Further, an opaque substrate such as a silicon wafer can be used in consideration of application to a reflection type liquid crystal display element.

<Conductive film for driving horizontal electric field>
The substrate has a conductive film for driving a lateral electric field.
As the conductive film, when the liquid crystal display element is a transmission type, ITO (Indium Tin Oxide: indium tin oxide), IZO (Indium Zinc Oxide: indium zinc oxide), and the like can be used, but the conductive film is not limited thereto.
In the case of a reflective liquid crystal display element, a light-reflective material such as aluminum can be used as the conductive film, but the conductive film is not limited thereto.
As a method for forming the conductive film on the substrate, a conventionally known method can be used.

The method for applying the above-described polymer composition onto a substrate having a conductive film for driving a lateral electric field is not particularly limited.
Industrially, the application method is generally performed by screen printing, offset printing, flexographic printing, an inkjet method, or the like. As other coating methods, there are a dip method, a roll coater method, a slit coater method, a spinner method (rotational coating method), a spray method and the like, and these may be used according to the purpose.

After applying the polymer composition on a substrate having a conductive film for driving an in-plane electric field, the composition is heated to 30 to 150 ° C., preferably 70 to 150 ° C. by a heating means such as a hot plate, a heat circulation type oven or an IR (infrared) type oven. The coating can be obtained by evaporating the solvent at 110 ° C. If the drying temperature is too low, the solvent tends to be insufficiently dried, and if the heating temperature is too high, thermal imidization proceeds, so that the photolysis reaction proceeds excessively by polarized light exposure, In this case, reorientation in one direction due to self-assembly becomes difficult, and the alignment stability may be impaired. Therefore, the drying temperature at this time is preferably a temperature at which thermal imidization of the specific polymer does not substantially proceed from the viewpoint of stability of liquid crystal alignment.
If the thickness of the coating film is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be reduced. Therefore, the thickness is preferably 5 nm to 300 nm, more preferably 10 nm to 150 nm. It is.
It is also possible to provide a step of cooling the substrate on which the coating film is formed to room temperature after the step [I] and before the subsequent step [II].

<Step [II]>
In step [II], the coating film obtained in step [I] is irradiated with polarized ultraviolet light. When irradiating the film surface of the coating film with polarized ultraviolet light, the substrate is irradiated with polarized ultraviolet light from a certain direction via a polarizing plate. As the ultraviolet rays to be used, ultraviolet rays having a wavelength in the range of 100 nm to 400 nm can be used. Preferably, an optimum wavelength is selected via a filter or the like depending on the type of the coating film to be used. Then, for example, ultraviolet rays having a wavelength in the range of 240 nm to 400 nm can be selected and used so that a photolysis reaction can be selectively induced. As the ultraviolet light, for example, light emitted from a high-pressure mercury lamp or a metal halide lamp can be used.

  The dose of the polarized ultraviolet light depends on the coating film used. The irradiation amount is a polarized ultraviolet ray that realizes a maximum value of ΔA (hereinafter, also referred to as ΔAmax), which is a difference between the ultraviolet ray absorbance in a direction parallel to the polarization direction of the polarized ultraviolet ray and the ultraviolet ray absorbance in a perpendicular direction in the coating film. Is preferably in the range of 1% to 70% of the amount, more preferably in the range of 1% to 50%.

<Step [III]>
In the step [III], the coating film irradiated with the ultraviolet light polarized in the step [II] is heated. Heating can impart orientation controllability to the coating film.
For heating, a heating means such as a hot plate, a heat circulation type oven or an IR (infrared) type oven can be used. The heating temperature can be determined in consideration of a temperature at which good stability of liquid crystal alignment and electric characteristics are exhibited in a coating film to be used.

  The heating temperature is preferably within a temperature range in which the main chain type polymer exhibits good stability of liquid crystal alignment. If the heating temperature is too low, the anisotropic amplification effect due to heat and thermal imidization tend to be insufficient, and if the heating temperature is too high, the anisotropy imparted by polarized light exposure is It tends to disappear, in which case it may be difficult to reorient in one direction due to self-assembly.

  The thickness of the coating film formed after heating is preferably 5 nm to 300 nm, more preferably 50 nm to 150 nm, for the same reason as described in the step [I].

  By having the above steps, the production method of the present invention can realize highly efficient introduction of anisotropy into a coating film. Then, a substrate with a liquid crystal alignment film can be manufactured with high efficiency.

<Step [IV]>
In the [IV] step, the substrate (first substrate) having a liquid crystal alignment film on the conductive film for driving a lateral electric field obtained in [III] is similarly processed with the above [I '] to [III']. The obtained substrate with a liquid crystal alignment film (second substrate) having no conductive film is disposed so as to face through a liquid crystal so that both liquid crystal alignment films face each other, and a liquid crystal cell is formed by a known method. This is a step of fabricating a horizontal electric field drive type liquid crystal display element. Steps [I ′] to [III ′] were performed in the same manner as in step [I] except that a substrate having no horizontal electric field driving conductive film was used instead of the substrate having the horizontal electric field driving conductive film. It can be performed in the same manner as in steps [I] to [III]. The difference between the steps [I] to [III] and the steps [I '] to [III'] is only the presence or absence of the conductive film described above, and thus the description of the steps [I '] to [III'] is omitted. I do.

  To give an example of manufacturing a liquid crystal cell or a liquid crystal display element, the above-described first and second substrates are prepared, spacers are scattered on the liquid crystal alignment film of one of the substrates, and the liquid crystal alignment film surface is on the inside. In this way, the other substrate is bonded and the liquid crystal is injected under reduced pressure to seal, or the liquid crystal is dropped on the surface of the liquid crystal alignment film on which the spacers are scattered, and then the substrate is bonded and sealed. , Etc. can be exemplified. At this time, it is preferable to use a substrate having an electrode having a structure like a comb tooth for driving a lateral electric field as the substrate on one side. At this time, the diameter of the spacer is preferably 1 μm to 30 μm, more preferably 2 μm to 10 μm. The spacer diameter determines the distance between the pair of substrates that sandwich the liquid crystal layer, that is, the thickness of the liquid crystal layer.

In the method for producing a substrate with a coating film of the present invention, a polymer composition is applied on a substrate to form a coating film, and then irradiated with polarized ultraviolet light. Next, by heating, a highly efficient introduction of anisotropy into the main chain type polymer film is realized, and a substrate with a liquid crystal alignment film having a liquid crystal alignment control ability is manufactured.
In the coating film used in the present invention, highly efficient introduction of anisotropy into the coating film is realized by utilizing the principle of molecular reorientation induced by self-organization based on the main chain photoreaction. In the production method of the present invention, in the case of a structure having a photodegradable group as a photoreactive group in the main chain type polymer, after forming a coating film on a substrate using the main chain type polymer, polarized ultraviolet light is irradiated. After irradiation and heating, a liquid crystal display element is formed.

  Therefore, the coating film used in the method of the present invention, by sequentially performing irradiation of polarized ultraviolet light and heat treatment to the coating film, anisotropic is introduced with high efficiency, and a liquid crystal alignment film excellent in alignment control ability and can do.

  In the coating film used in the method of the present invention, the irradiation amount of polarized ultraviolet light to the coating film and the heating temperature in the heat treatment are optimized. Thereby, highly efficient introduction of anisotropy into the coating film can be realized.

  The irradiation amount of the polarized ultraviolet light that is optimal for introducing highly efficient anisotropy into the coating film used in the present invention is the irradiation amount of the polarized ultraviolet light that optimizes the amount of the photosensitive group that undergoes photolysis reaction in the coating film. Corresponding. As a result of irradiating the coating film used in the present invention with polarized ultraviolet light, if the number of photosensitive groups that undergo photolysis reaction is small, the amount of photoreaction will not be sufficient. In that case, even after heating, sufficient self-organization does not proceed.

  Therefore, in the coating film used in the present invention, the optimum amount of the photolytic reaction of the photosensitive group by irradiation with polarized ultraviolet rays is preferably 0.1 mol% to 90 mol% of the polymer film. It is more preferable that the content be 0.1 mol% to 80 mol%. By setting the amount of the photosensitive group that undergoes photoreaction in such a range, the self-assembly in the subsequent heat treatment proceeds efficiently, and highly efficient anisotropy can be formed in the film.

  In the coating film used in the method of the present invention, the amount of photolysis reaction of the photosensitive group in the main chain of the polymer film is optimized by optimizing the irradiation amount of polarized ultraviolet light. And, together with the subsequent heat treatment, highly efficient introduction of anisotropy into the coating film used in the present invention is realized. In that case, a suitable amount of polarized ultraviolet light can be determined based on the evaluation of the ultraviolet absorption of the coating film used in the present invention.

  That is, for the coating film used in the present invention, after the irradiation of the polarized ultraviolet light, the ultraviolet absorption in the direction parallel to the polarization direction of the polarized ultraviolet light and the ultraviolet absorption in the perpendicular direction are measured. From the measurement results of the ultraviolet absorption, ΔA, which is the difference between the ultraviolet absorbance in the direction parallel to the polarization direction of the polarized ultraviolet light and the ultraviolet absorbance in the direction perpendicular to the coating film, is evaluated. Then, the maximum value (ΔAmax) of ΔA realized in the coating film used in the present invention and the irradiation amount of polarized ultraviolet rays for realizing it are obtained. In the production method of the present invention, a preferable amount of polarized ultraviolet light to be irradiated in the production of the liquid crystal alignment film can be determined based on the amount of polarized ultraviolet light that achieves the ΔAmax.

  As described above, in the production method of the present invention, in order to realize highly efficient introduction of anisotropy into a coating film, as described above, the temperature range in which the main chain type polymer provides liquid crystal alignment stability is used as a reference. A suitable heating temperature may be determined. Therefore, for example, the temperature range in which the main chain type polymer used in the present invention provides the liquid crystal alignment stability may be determined in consideration of the temperature at which the coating film used exhibits good liquid crystal alignment stability and electrical characteristics. It can be set in a temperature range according to a conventional liquid crystal alignment film made of polyimide or the like. That is, the heating temperature after irradiation with the polarized ultraviolet rays is preferably from 150 ° C. to 300 ° C., and more preferably from 180 ° C. to 250 ° C. By doing so, greater anisotropy is imparted to the coating film used in the present invention.

  By doing so, the liquid crystal display device provided by the present invention exhibits high reliability against external stress such as light and heat.

  As described above, the substrate for a lateral electric field drive type liquid crystal display element manufactured using the polymer of the present invention or the lateral electric field drive type liquid crystal display element having the substrate has excellent reliability and a large screen. And can be suitably used for a high-definition liquid crystal television. In addition, the liquid crystal alignment film manufactured by the method of the present invention has excellent liquid crystal alignment stability and reliability, so that it can be used for a variable phase shifter using liquid crystal. For example, it can be suitably used for an antenna capable of changing the resonance frequency.

Hereinafter, the present invention will be specifically described with reference to examples and the like, but the present invention is not limited to these examples.
The abbreviations of the compound and the solvent are as follows.
NMP: N-methyl-2-pyrrolidone BCS: butyl cellosolve DA-1: Compound DA-2 represented by the following structural formula (DA-1): Compound DA-3 represented by the following structural formula (DA-2): Compound DA-4 represented by the following structural formula (DA-3): Compound DA-5 represented by the following structural formula (DA-4): Compound DA-6 represented by the following structural formula (DA-5) : Compound DA-7 represented by the following structural formula (DA-6): Compound DA-8 represented by the following structural formula (DA-7): Compound CA- represented by the following structural formula (DA-8) 1: Compound CA-2 represented by the following structural formula (CA-1): Compound CA-3 represented by the following structural formula (CA-2): Compound represented by the following structural formula (CA-3)

<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.) using a sample volume of 1.1 mL, a cone rotor TE-1 (1 ° 34 ′, R24), and a temperature of 25. Measured in ° C.

<Synthesis Example 1>
3.91 g (13.0 mmol) of DA-1 was weighed and placed in a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 25.7 g of NMP was added, and the mixture was stirred and dissolved while sending nitrogen. While stirring this diamine solution under water cooling, 1.76 g (8.97 mmol) of CA-1 was added, and the mixture was stirred at 23 ° C. for 3 hours under a nitrogen atmosphere, and then 0.81 g (3.25 mmol) of CA-2. 11.0 g of NMP was further added, and the mixture was stirred at 50 ° C. for 20 hours under a nitrogen atmosphere to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 571 mPa · s.

  12.1 g of the polyamic acid solution was placed in a 100 mL Erlenmeyer flask containing a stirrer, 16.1 g of NMP and 12.1 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours to give a liquid crystal aligning agent ( PAA-1) was obtained.

<Synthesis Example 2>
2.79 g (14.0 mmol) of DA-2 and 1.47 g (6.00 mmol) of DA-3 were weighed into a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and 50.5 g of NMP was added. The mixture was stirred and dissolved while supplying nitrogen. While stirring the diamine solution under water cooling, 5.59 g (19.0 mmol) of CA-3 was added, 21.7 g of NMP was further added, and the mixture was stirred at 50 ° C. for 20 hours under a nitrogen atmosphere to obtain a solution of the polyamic acid. Obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 480 mPa · s.

  14.5 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask containing a stirrer, 12.6 g of NMP and 11.6 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours to give a liquid crystal aligning agent ( PAA-2) was obtained.

<Synthesis Example 3>
1.59 g (8.00 mmol) of DA-2 and 0.40 g (2.00 mmol) of DA-4 were weighed and placed in a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and 24.0 g of NMP was added. The mixture was stirred and dissolved while supplying nitrogen. While stirring this diamine solution under water cooling, 1.81 g (9.25 mmol) of CA-1 was added, further 10.3 g of NMP was added, and the mixture was stirred at 23 ° C. for 4 hours under a nitrogen atmosphere to obtain a solution of the polyamic acid. Obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 134 mPa · s.

  17.7 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask containing a stirrer, 9.83 g of NMP and 11.8 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours to give a liquid crystal aligning agent ( PAA-3) was obtained.

<Synthesis example 4>
1.49 g (7.00 mmol) of DA-5 and 0.73 g (3.00 mmol) of DA-3 were weighed into a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and 25.8 g of NMP was added. The mixture was stirred and dissolved while supplying nitrogen. While stirring the diamine solution under water cooling, 2.80 g (9.50 mmol) of CA-3 was added, and 11.0 g of NMP was further added. The mixture was stirred at 50 ° C. for 20 hours under a nitrogen atmosphere to obtain a solution of the polyamic acid. Obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 432 mPa · s.

  14.7 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask containing a stirrer, 12.7 g of NMP and 11.8 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours to give a liquid crystal aligning agent ( PAA-4) was obtained.

<Synthesis example 5>
In a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 0.80 g (4.0 mmol) of DA-2, 0.73 g (3.00 mmol) of DA-3, and 1.18 g of DA-6 ( 3.00 mmol) was weighed, 28.3 g of NMP was added, and the mixture was stirred and dissolved while sending nitrogen. While stirring the diamine solution under water cooling, 2.80 g (9.50 mmol) of CA-3 was added, and 12.1 g of NMP was further added. Obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 512 mPa · s.

  14.5 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask containing a stirrer, 12.6 g of NMP and 11.6 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours to give a liquid crystal aligning agent ( PAA-5) was obtained.

<Comparative Synthesis Example 1>
In a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 3.54 g (13.0 mmol) of DA-7 was weighed, 24.2 g of NMP was added, and the mixture was stirred and dissolved while sending nitrogen. While stirring this diamine solution under water cooling, 1.76 g (8.97 mmol) of CA-1 was added, and the mixture was stirred at 23 ° C. for 3 hours under a nitrogen atmosphere, and then 0.81 g (3.25 mmol) of CA-2. Then, 10.4 g of NMP was further added, and the mixture was stirred at 50 ° C. for 20 hours under a nitrogen atmosphere to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 627 mPa · s.

  11.9 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask containing a stirrer, 15.9 g of NMP and 11.9 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours to give a liquid crystal aligning agent ( PAA-a) was obtained.

<Comparative Synthesis Example 2>
4.27 g (13.0 mmol) of DA-8 was weighed and placed in a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 27.1 g of NMP was added, and the mixture was stirred and dissolved while feeding nitrogen. While stirring this diamine solution under water cooling, 1.76 g (8.97 mmol) of CA-1 was added, and the mixture was stirred at 23 ° C. for 3 hours under a nitrogen atmosphere, and then 0.81 g (3.25 mmol) of CA-2. 11.6 g of NMP was further added, and the mixture was stirred at 50 ° C. for 20 hours under a nitrogen atmosphere to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 483 mPa · s.

  12.2 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask containing a stirrer, 16.3 g of NMP and 12.2 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours to give a liquid crystal aligning agent ( PAA-b) was obtained.

<Example 1>
4.03 g of the polyimide solution (PAA-1) obtained in Synthesis Example 1 and 6.05 g of the polyamic acid solution (PAA-2) obtained in Synthesis Example 2 were weighed into a 50 mL Erlenmeyer flask containing a stirrer. The mixture was stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-1).

<Example 2>
In a 50 mL Erlenmeyer flask containing a stirrer, 4.01 g of the polyimide solution (PAA-1) obtained in Synthesis Example 1 and 6.02 g of the polyamic acid solution (PAA-3) obtained in Synthesis Example 3 were weighed. The mixture was stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-2).

<Example 3>
In a 50 mL Erlenmeyer flask containing a stirrer, 4.04 g of the polyimide solution (PAA-1) obtained in Synthesis Example 1 and 6.07 g of the polyamic acid solution (PAA-4) obtained in Synthesis Example 4 were weighed. The mixture was stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-3).

<Example 4>
In a 50 mL Erlenmeyer flask containing a stirrer, 4.03 g of the polyimide solution (PAA-1) obtained in Synthesis Example 1 and 6.04 g of the polyamic acid solution (PAA-5) obtained in Synthesis Example 5 were weighed. The mixture was stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-4).

<Comparative Example 1>
The polyimide solution (PAA-1) obtained in Synthesis Example 1 was used as a liquid crystal aligning agent (B-1).

<Comparative Example 2>
4.03 g of the polyimide solution (PAA-a) obtained in Comparative Synthesis Example 1 and 6.05 g of the polyamic acid solution (PAA-2) obtained in Synthesis Example 2 were placed in a 50 mL Erlenmeyer flask containing a stirrer. It was weighed and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (B-2).

<Comparative Example 3>
4.00 g of the polyimide solution (PAA-b) obtained in Comparative Synthesis Example 2 and 6.00 g of the polyamic acid solution (PAA-2) obtained in Synthesis Example 2 were placed in a 50 mL Erlenmeyer flask containing a stirrer. It was weighed and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (B-3).

<Production of liquid crystal cell for evaluating liquid crystal orientation and relaxation characteristics of accumulated charge>
Hereinafter, a method for manufacturing a liquid crystal cell for evaluating liquid crystal orientation and relaxation characteristics of accumulated charge will be described.
A liquid crystal cell having a configuration of an FFS type liquid crystal display element was manufactured. First, a substrate with electrodes was prepared. The substrate is a glass substrate having a size of 30 mm × 35 mm and a thickness of 0.7 mm. An IZO electrode constituting a counter electrode as a first layer was formed on the entire surface of the substrate. On the counter electrode of the first layer, a SiN (silicon nitride) film formed by a CVD method was formed as a second layer. The second-layer SiN film has a thickness of 500 nm and functions as an interlayer insulating film. A comb-shaped pixel electrode formed by patterning an IZO film was disposed as a third layer on the second-layer SiN film, and two pixels, a first pixel and a second pixel, were formed. . The size of each pixel is 10 mm long and about 5 mm wide. At this time, the first layer counter electrode and the third layer pixel electrode are electrically insulated by the action of the second layer SiN film.

  The pixel electrode of the third layer is a comb tooth formed by arranging a plurality of square-shaped electrode elements whose central part is bent, similarly to the diagram described in Japanese Patent Application Laid-Open No. 2014-77845. It has the shape of a letter. The width in the lateral direction of each electrode element is 3 μm, and the interval between the electrode elements is 6 μm. Since the pixel electrode forming each pixel is formed by arranging a plurality of bent-shaped electrode elements in the central portion, the shape of each pixel is not rectangular but bent at the central portion like the electrode element. , And have a shape resembling a bold letter. Each pixel is vertically divided by a center bent portion, and has a first region above the bent portion and a second region below the bent portion.

  When the first region and the second region of each pixel are compared, the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, the electrode elements of the pixel electrode are formed so as to form an angle of + 10 ° (clockwise) in the first region of the pixel, with reference to the direction of a line segment obtained by projecting a polarization plane of polarized ultraviolet light to be described later on the substrate. Then, in the second region of the pixel, the electrode element of the pixel electrode was formed so as to form an angle of -10 ° (clockwise). That is, in the first region and the second region of each pixel, the direction of the rotation operation (in-plane switching) of the liquid crystal induced by the application of the voltage between the pixel electrode and the counter electrode in the substrate plane is as follows. They were configured to be in opposite directions.

  Next, the liquid crystal aligning agents obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were filtered through a 1.0 μm filter, and then applied to the prepared substrate with electrodes by spin coating. Next, it was dried on a hot plate set at 70 ° C. for 90 seconds. Then, using an exposure apparatus: APL-L050121S1S-APW01 manufactured by Ushio Inc., the substrate was irradiated with linearly polarized ultraviolet light from a vertical direction through a wavelength selection filter and a polarizing plate. At this time, the direction of the polarization plane was set such that the direction of the line segment obtained by projecting the polarization plane of the polarized ultraviolet rays onto the substrate was inclined by 10 ° with respect to the third-layer IZO comb-teeth electrode. Next, baking was performed in an IR (infrared) type oven set at 230 ° C. for 30 minutes to obtain an alignment-treated substrate having a 100 nm-thick polyimide liquid crystal alignment film. In addition, a substrate with a polyimide liquid crystal alignment film, which was subjected to an alignment treatment in the same manner as described above, was also obtained on a glass substrate having a columnar spacer having a height of 4 μm and having an ITO electrode formed on the back surface as a counter substrate. A pair of these two substrates with a liquid crystal alignment film was formed, and a sealant was printed on one of the substrates while leaving a liquid crystal injection port. Lamination was performed by bonding such that the direction of the line segment where the polarization plane was projected onto the substrate was parallel. Thereafter, the sealing agent was cured to produce an empty cell having a cell gap of 4 μm. Liquid crystal MLC-7026-100 (negative liquid crystal manufactured by Merck) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS type liquid crystal cell. After that, the obtained liquid crystal cell was heated at 120 ° C. for 30 minutes, left at 23 ° C. overnight, and then used for evaluation of liquid crystal orientation and relaxation property of accumulated charge.

<Evaluation of liquid crystal orientation>
Using the above liquid crystal cell, an alternating voltage of 16 VPP was applied for 96 hours at a frequency of 30 Hz under a constant temperature environment of 70 ° C. Thereafter, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited, and left at 23 ° C. overnight.

  After standing, the liquid crystal cell is placed between two polarizing plates arranged so that the polarization axes are orthogonal to each other, and the backlight is turned on without applying a voltage so that the luminance of the transmitted light is minimized. The arrangement angle of the liquid crystal cell was adjusted. Then, the rotation angle when the liquid crystal cell was rotated from the angle at which the second region of the first pixel was darkest to the angle at which the first region was darkest was calculated as the angle Δ. Similarly, the second pixel was compared with the second region and the first region, and the same angle Δ was calculated. Then, the average value of the angle Δ values of the first pixel and the second pixel was calculated as the angle Δ of the liquid crystal cell. When the value of the angle Δ of the liquid crystal cell was less than 1.0 °, it was defined as “good”, and when the value of the angle Δ was 1.0 ° or more, it was defined as “bad” and evaluated.

<Evaluation of relaxation characteristics of accumulated charge>
The liquid crystal cell is placed between two polarizing plates arranged so that the polarizing axes are orthogonal to each other, and the pixel electrode and the counter electrode are short-circuited to have the same electric potential. The backlight was irradiated, and the angle of the liquid crystal cell was adjusted so that the luminance of the transmitted light of the LED backlight measured on the two polarizing plates was minimized.

  Next, a VT characteristic (voltage-transmittance characteristic) at a temperature of 23 ° C. was measured while applying a rectangular wave having a frequency of 30 Hz to the liquid crystal cell, and an AC voltage having a relative transmittance of 23% was measured. Calculated. Since this AC voltage corresponds to a region where the change in luminance with respect to the voltage is large, it is convenient to evaluate the accumulated charge via the luminance.

  Next, after applying a rectangular wave having a relative transmittance of 23% at a temperature of 23 ° C. and a frequency of 30 Hz for 5 minutes, a DC voltage of +1.0 V was superimposed and driven for 30 minutes. Thereafter, the DC voltage was cut off, and only an AC voltage having a relative transmittance of 23% and a rectangular wave having a frequency of 30 Hz was applied again for 30 minutes.

The faster the relaxation of the accumulated charge, the faster the charge accumulation in the liquid crystal cell when the DC voltage is superimposed. Therefore, the relaxation characteristic of the accumulated charge is such that the relative transmittance immediately after the superposition of the DC voltage is 30% or more. From this, it was evaluated to what extent the relative transmittance after 30 minutes decreased. That is, when the relative transmittance was reduced to less than 28% 30 minutes after the superimposition of the DC voltage, the evaluation was defined as "good", and when the relative transmittance was 28% or more, the evaluation was defined as "poor".

<Preparation of liquid crystal cell for evaluating voltage holding ratio>
Using a glass substrate with an ITO electrode and spraying a 4 μm bead spacer on the surface of the liquid crystal alignment film on one of the substrates before printing the sealant, the above liquid crystal for evaluating the liquid crystal alignment and the relaxation characteristics of accumulated charge A liquid crystal cell for measuring a voltage holding ratio was manufactured in the same procedure as that for manufacturing the cell.

<Evaluation of voltage holding ratio>
The voltage holding ratio was evaluated using the above liquid crystal cell. Specifically, an AC voltage of 2 VPP is applied to the liquid crystal cell obtained by the above method at a temperature of 70 ° C. for 60 μsec, and the voltage after 167 milliseconds is measured to determine how much the voltage can be maintained. It was calculated as a voltage holding ratio (also referred to as VHR). Note that the measurement was performed using a voltage holding ratio measuring device (VHR-1, manufactured by Toyo Corporation) at a setting of Voltage: ± 1 V, Pulse Width: 60 μs, and Frame Period: 167 ms. When the value of the voltage holding ratio of this liquid crystal cell was 95% or more, it was defined as "good", and when the value of the voltage holding ratio was less than 95%, it was defined as "bad" and evaluated.

<Example 5>
Using the liquid crystal aligning agent (A-1) obtained in Example 1, two types of liquid crystal cells were produced as described above. Irradiation with polarized ultraviolet light was performed using a high-pressure mercury lamp through a wavelength selection filter: 240 LCF and a 254 nm type polarizing plate. The irradiation amount of polarized ultraviolet light is measured by measuring the amount of light using an illuminometer UVD-S254SB manufactured by Ushio Inc., and changing the light amount within a range of 600 to 1800 mJ / cm ² at a wavelength of 254 nm. Three or more liquid crystal cells having different amounts were produced.

As a result of evaluating the liquid crystal orientation of these liquid crystal cells, the irradiation amount of polarized ultraviolet light having the best angle Δ was 1500 mJ / cm ² , and the angle Δ was 0.56 °, which was good.
The relaxation property of the accumulated charge at the same irradiation amount of polarized ultraviolet light, which was evaluated before the evaluation of the liquid crystal orientation, was good because the relative transmittance after 30 minutes of DC voltage superposition was 26.0%. .
The voltage holding ratio of a liquid crystal cell manufactured with the same amount of polarized ultraviolet light was evaluated. As a result, the voltage holding ratio was 96.8%, which was good.

<Examples 6 to 8>
Except for using the liquid crystal aligning agents obtained in Examples 2 to 4, the liquid crystal alignment, the relaxation property of accumulated charge, and the voltage holding ratio were evaluated in the same manner as in Example 5.

<Comparative Examples 4 to 6>
Except that the liquid crystal aligning agents obtained in Comparative Examples 1 to 3 were used, the liquid crystal alignment, the relaxation property of accumulated charge, and the voltage holding ratio were evaluated in the same manner as in Example 5.

  Table 1 shows that when the liquid crystal aligning agents obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were used, the irradiation amount of polarized ultraviolet light having the best angle Δ and the evaluation result of liquid crystal alignment showed that the accumulated charge was The results of the evaluation of the relaxation characteristics and the results of the evaluation of the voltage holding ratio are shown.

As shown in Table 1, in Examples 5 to 8, the angle Δ, which is the difference between the orientation azimuths before and after the AC driving, is less than 1.0 °, which is good, and at the same time, the DC voltage showing the relaxation characteristic of the accumulated charge. The relative transmittance after 30 minutes of superposition is good at less than 28.0%, and the voltage holding ratio is good at 95% or more, showing good characteristics. Since both have good afterimage characteristics, the display quality of the liquid crystal display device is good. Excellent improvement. On the other hand, in Comparative Examples 4 to 6, all of the angle Δ, the relative transmittance after 30 minutes of the superimposition of the DC voltage, and the voltage holding ratio did not give good results.
As described above, it was confirmed that the liquid crystal display device manufactured by the method of the present invention exhibited extremely excellent afterimage characteristics.

A substrate for a lateral electric field driving type liquid crystal display element manufactured using the composition of the present invention or a lateral electric field driving type liquid crystal display element having the substrate has excellent reliability, and has a large screen and a high definition liquid crystal television. It can be suitably used for such purposes. In addition, the liquid crystal alignment film manufactured by the method of the present invention has excellent liquid crystal alignment stability and reliability, so that it can be used for a variable phase shifter using liquid crystal. For example, it can be suitably used for an antenna capable of changing the resonance frequency.

Claims (7)

At least one polymer (A) selected from a polyamic acid obtained by using a tetracarboxylic dianhydride component and a diamine component containing a diamine represented by the following formula (1) and an imidized polymer of the polyamic acid; )When,
At least one polymer (B) selected from a polyamic acid obtained by using a tetracarboxylic dianhydride component and a diamine component containing a diamine represented by the following formula (2) and an imidized polymer of the polyamic acid: ).

In formula (1), X - _(CH 2) n- and represents, n represents - (CH ₂₎ - is 8 or a natural number of 9 indicating the number of, any - (CH ₂₎ - each independently , -O-, -S-, -COO-, -OCO-, -CONH- and -NHCO-, these groups may be replaced under non-adjacent conditions, and R ₁ and R ₂ Are each independently a monovalent organic group, and p1 and p2 are each independently an integer of 0 to 4.
In the formula (2), Y ₁ is 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 heterocyclic ring, and B ₁ and B ₂ are each independently A hydrogen atom or an alkyl group, alkenyl group, or alkynyl group having 1 to 10 carbon atoms which may have a substituent. _{Y 1} in the formula (2) is at least one selected from the following structures formula (YD-1) ~ (YD -5), a liquid crystal aligning agent of claim 1.

(In the formula (YD-1), A ₁ is a nitrogen-containing heterocycle having 3 to 15 carbon atoms, and Z ₁ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. In the formula (YD-2), W ₁ is a hydrocarbon group having 1 to 10 carbon atoms, A ₂ is a monovalent organic group having 3 to 15 carbon atoms having a nitrogen atom-containing heterocyclic ring, or It is a disubstituted amino group substituted with an aliphatic group having 1 to 6. In the formula (YD-3), W ₂ is a divalent having 6 to 15 carbon atoms and having 1 to 2 benzene rings. An organic group, W ₃ is a C 2 to C 18 divalent organic group containing a C 2 to C 5 alkylene or biphenylene or nitrogen-containing heterocycle, Z ₂ is a hydrogen atom, a C 1 to C 5 And a is an integer of 0 to 1. In the formula (YD-4), A ₃ is a nitrogen-containing heterocycle having ₃ to 15 carbon atoms, In the formula (YD-5), A ₄ is a nitrogen-containing heterocycle having 3 to 15 carbon atoms, and W ₅ is a C 2 to ₅ carbon atom. Is an alkylene). A ₁ , A ₂ , A ₃ , and A ₄ described in formulas (YD-1), (YD-2), (YD-4), and (YD-5) are pyrrolidine, pyrrole, imidazole, pyrazole, The liquid crystal alignment agent according to claim 1 or 2, wherein the liquid crystal alignment agent is at least one selected from the group consisting of oxazole, thiazole, piperidine, piperazine, pyridine, pyrazine, indole, benzimidazole, quinoline, isoquinoline, and carbazole. 4. The method according to claim ₁ , wherein Y ₁ in the formula (2) is at least one selected from the group consisting of divalent organic groups having the structures of the following formulas (YD-6) to (YD-22). The liquid crystal aligning agent according to any one of claims 1 to 7.

(In the formula (YD-17), h is an integer of 1 to 3, and in the formulas (YD-14), (YD-21), and (YD-22), j is an integer of 0 to 3). Y ₁ in the formula (2) is selected from the group consisting of divalent organic groups having the structures of the above formulas (YD-14), (YD-18), (YD-21) and (YD-22). The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the liquid crystal aligning agent is at least one type.   A liquid crystal alignment film obtained by using the liquid crystal alignment agent according to claim 1. A liquid crystal display device comprising the liquid crystal alignment film according to claim 6.