KR102421827B1 - Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display element - Google Patents

Abstract

The soluble polyimide obtained from the diamine component containing at least 1 sort(s) of diamine chosen from the diamine of following formula (i), (ii), and tetracarboxylic dianhydride component is contained, The liquid crystal aligning agent characterized by the above-mentioned. Definitions of symbols in formulas are as described in the specification.

Description

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

This invention relates to the liquid crystal aligning agent mainly used for the liquid crystal display element of a transverse electric field drive system, the liquid crystal aligning film using the same, and a transverse electric field drive system liquid crystal display element.

A liquid crystal display element WHEREIN: The liquid crystal aligning film is playing the role of orientating a liquid crystal in a fixed direction. Currently, the main liquid crystal aligning film used industrially is manufactured by apply|coating and forming into a film the polyimide-type liquid crystal aligning agent which consists of a polyamic acid (it is also called polyamic acid) which is a polyimide precursor, or a polyimide solution, on a board|substrate. do. Moreover, when carrying out the parallel orientation or diagonal orientation of a liquid crystal with respect to a board|substrate surface, after forming into a film, the surface extending|stretching process by rubbing is further performed. Moreover, the method of using the anisotropic photochemical reaction by polarization|polarized-light ultraviolet irradiation etc. is also proposed as a substitute for a rubbing process, and examination toward industrialization is performed in recent years.

For the improvement of the display characteristics of a liquid crystal display element, by variously changing and optimizing the structure of a polyamic acid or a polyimide, blending resin from which a characteristic differs, adding an additive, etc., liquid-crystal orientation improvement and free Numerous techniques have been proposed in that it is possible to control the tilt angle, improve electrical characteristics, and the like, and further improve display characteristics. For example, in order to obtain a high voltage retention, it is proposed to use the polyimide resin which has a specific repeating structure (refer patent document 1 etc.). Moreover, shortening time until a residual image is erase|eliminates by using the soluble polyimide which has nitrogen atoms other than an imide group with respect to a residual image phenomenon is proposed (refer patent document 2 etc.). Moreover, the polyamic acid obtained from the specific diamine containing oxazole or imidazole skeleton, and tetracarboxylic dianhydride, and its derivative(s) are proposed (patent document 3).

In recent years, liquid crystal display elements have been widely used for large-screen and high-definition liquid crystal televisions and for vehicle-mounted applications, for example, car navigation systems and meter panels. In such a use, in order to obtain high luminance, a backlight having a large amount of heat may be used. For this reason, high reliability from another viewpoint, ie, high stability with respect to the light and heat|fever from a backlight, came to be calculated|required by a liquid crystal aligning film. In particular, when the voltage retention, which is one of the electrical characteristics, is lowered by light irradiation from the backlight, burn-in failure (line burn-in), which is one of the display defects of the liquid crystal display element, tends to occur, and a highly reliable liquid crystal display element will not be able to obtain In addition, in the transverse electric field mode, burn-in (AC burn-in) due to misalignment of the orientation direction is a problem, and in particular, since it tends to occur due to heat, the solution is difficult. Therefore, in a liquid crystal aligning film, in addition to having a favorable initial stage characteristic, for example, even after being exposed to light irradiation for a long time, it is also calculated|required that voltage retention is hard to fall.

Japanese Laid-Open Patent Publication No. 2-287324 Japanese Patent Laid-Open No. 10-104633 Japanese Patent Laid-Open No. 2010-54872 WO2006-126555

The present invention has been made in view of the above circumstances, and in addition to providing a liquid crystal aligning agent having good printability (solubility of polymer in solvent) to substrates etc., and excellent rubbing tolerance and good display properties, reliability is It aims at providing the liquid crystal aligning film for liquid crystal display elements of the transverse electric field drive system which has outstanding reliability with respect to the case where insufficient liquid crystal is used, or the case where it is exposed to high temperature or backlight light over a long period of time.

As a result of earnestly researching, this inventor discovered that the liquid crystal aligning agent containing a specific soluble polyimide and polyamic acid was very effective in order to achieve said objective, and came to complete this invention.

That is, this invention has the following summary.

The soluble polyimide obtained from the diamine component containing at least 1 sort(s) of diamine chosen from the diamine of <1> following formula (i), (ii), and tetracarboxylic dianhydride component is contained, The liquid crystal aligning agent characterized by the above-mentioned .

[Formula 1]

In formula, D represents a divalent C1-C20 saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic ring, and D may have various substituents. E is a single bond, or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and F is a single bond or an ether bond (-O-), an ester bond (-OCO-, -COO-). m is 1 or 0.

<2> Furthermore, the polyamic acid obtained using at least 1 type or more of the compound represented by Formula (iii) - (vi) is contained, The liquid crystal aligning agent as described in <1> characterized by the above-mentioned.

[Formula 2]

In formula (vi), R represents a hydrogen atom or a C1-C8 hydrocarbon group.

<3> The said soluble polyimide is a soluble polyimide obtained from the diamine component containing 10-90 mol% of at least 1 sort(s) of diamine chosen from the diamine of Formula (i) and (ii), and tetracarboxylic dianhydride , The liquid crystal aligning agent as described in <1> or <2>.

The liquid crystal aligning agent in any one of <1>-<3> whose imidation rate of the <4> said soluble polyimide is 20 % - 100 %.

<5> <1> to < in which the said soluble polyimide is a soluble polyimide obtained from the diamine component containing at least 1 or more types of diamine selected from Formula (vii) - a formula (x), and tetracarboxylic dianhydride 4> The liquid crystal aligning agent in any one of.

[Formula 3]

n represents an integer of 1 to 6, R ₃ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₄ is a linear alkylene group having 1 to 5 carbon atoms.

<6> <1> to <5 in which 1-10 mass % of the said soluble polyimide and the said polyamic acid are contained in total, and ratio of the weight of the said polyimide to the weight of the said polyamic acid is 95:5-5:95 > The liquid crystal aligning agent in any one of.

<7> The liquid crystal aligning film obtained using the liquid crystal aligning agent as described in <1>-<6>.

<8> The liquid crystal aligning film as described in <7> was provided, The liquid crystal display element characterized by the above-mentioned.

The liquid crystal aligning agent of this invention is obtained from the diamine component containing at least 1 sort(s) of diamine (it is also called specific diamine hereafter) chosen from the diamine of said formula (i) and (ii), and tetracarboxylic dianhydride It is characterized by containing a soluble polyimide. Since said soluble polyimide has high solubility with respect to a solvent, and the compatibility with respect to polyamic acid at the time of blending with a polyamic acid is also very favorable, the liquid crystal aligning agent using them is excellent in application|coating and film-forming property with respect to a board|substrate, and unevenness|corrugation With this small amount, a good quality film can be obtained. In addition, specific diamines have a characteristic of generating highly active substituents by heating, and some of them undergo a condensation reaction on their own to change into a structure with good linearity, and react with a specific site of amic acid in a portion in contact with amic acid For this reason, it is excellent in liquid-crystal orientation and the liquid crystal aligning film excellent in rubbing tolerance is obtained. Concomitantly with this, high-quality black display is also possible.

Moreover, since said soluble polyimide is very stable with respect to light and heat, and has a function of making very small influence of an ionic impurity etc., the liquid crystal aligning film containing said soluble polyimide is very weak against contamination, a negative type Very high reliability can be obtained also in liquid crystals and the like.

Moreover, the polyamic acid using the compound represented by Formula (iii) - (vi) has the characteristic which discharge|releases the residual electric charge accumulated in the alignment film quickly, and, thereby, can obtain the alignment film excellent in a burn-in characteristic. On the other hand, although the oriented film using such a polyamic acid tends to lack reliability, it becomes possible to acquire the outstanding reliability and the outstanding burn-in characteristic by combining with the soluble polyimide of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

<Soluble polyimide>

The liquid crystal aligning agent of this invention contains the diamine component containing specific diamine, and the soluble polyimide obtained from tetracarboxylic dianhydride. Specific diamine has an organic group which can be detached by heat. By desorption of the organic group, an amino group can be generated.

[Formula 4]

In formula, D represents a divalent C1-C20 saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic ring, and D may have various substituents. E is a single bond, or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and F is a single bond or an ether bond (-O-), an ester bond (-OCO -, -COO-). m is 1 or 0.

Although the substitution position of the amino group in said formula (i) and (i) is not specifically limited, From a viewpoint of synthetic|combination difficulty and availability of a reagent, when it is based on an amide bond, a meta or para position is preferable, and a viewpoint of liquid-crystal orientation The position of para is particularly preferred in Also in aminobenzenes that do not have an amino group (i.e., -NHBoc) protected by a tertiary butoxycarbonyl group (hereinafter, also referred to as Boc group), similarly, the meta or para position is preferably based on the amide bond. And the meta position is preferable from a solubility viewpoint, and the para position is preferable from a viewpoint of liquid-crystal orientation. In addition, hydrogen of aminobenzene having no -NHBoc may be substituted with an organic group or a halogen atom such as fluorine.

D in Formula (i) is not limited, According to structures, such as dicarboxylic acid and tetracarboxylic dianhydride used as a raw material, various structures can be selected. As D, a divalent hydrocarbon group is preferable from a solubility viewpoint, and a linear alkylene group, a cyclic alkylene group, etc. are mentioned as a preferable example, This hydrocarbon group may have an unsaturated bond. Moreover, from a viewpoint of liquid-crystal orientation or an electrical characteristic, a bivalent aromatic hydrocarbon group, a heterocyclic ring, etc. are preferable. Although it is preferable that D does not have a substituent from a viewpoint of liquid-crystal orientation, it is preferable from a soluble viewpoint that the hydrogen atom is substituted by the carboxylic acid group, a fluorine atom, etc.

There is no limitation in particular about the ratio of a specific diamine among the diamine components at the time of synthesize|combining the soluble polyimide in the liquid crystal aligning agent of this invention, For the purpose of provision of various functions, such as solubility improvement and improvement of an electrical property, adjusted in some cases. When using by a transverse electric field system, the very excellent liquid-crystal orientation can be acquired by combining the diamine represented by Formula (vii) - Formula (x).

[Formula 5]

In formulas (viii) and (ix), n represents an integer of 1 to 6, in formula (x), R ₃ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₄ is a direct group having 1 to 5 carbon atoms. It is a chain alkylene group.

The ratio of the specific diamine specifically, used for this invention is 1-90 mol%, Preferably it is 1-50 mol%, More preferably, it is 5-30 mol%. Moreover, it is preferable to contain the diamine represented by (vii)-(x) at least 10 mol% or more.

As diamine used for the synthesis|combination of a soluble polyimide, you may use together other diamine other than the diamine mentioned above for the purpose of provision of various functions. The specific structure of another diamine is represented by the following general formula (3).

[Formula 6]

Y represents a divalent organic group. Although the example is shown below, it is not limited to it. In addition, the dotted portion refers to a portion bonded to nitrogen of -NH ₂ .

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

For the purpose of improving the liquid crystal orientation, as examples of diamines preferably introduced, Y-20, Y-29, Y-30, Y-31, Y-32, Y-33, Y-40, Y-47, Y -48, Y-53, Y-54, Y-55, Y-56, Y-58, Y-59, Y-60, Y-61, Y-64, Y-68, Y-69, Y-70 and Y-71. On the other hand, as for the monomer with good orientation, there are many things of a linear structure, and when used for a soluble polyimide, the solubility of a polyimide is insufficient and it may become impossible to adjust. It may be solvable by selecting various structures of tetracarboxylic dianhydride demonstrated later about this. Y-29, Y-30, Y-31, Y-32, Y-60 etc. are mentioned as a structure especially preferable from a viewpoint of solubility and liquid-crystal orientation. Further, in Y-29, Y-30, Y-31, and Y-32, one hydrogen of the aliphatic amine may be substituted with an alkyl group having a relatively small carbon number such as a methyl group or an ethyl group, an alkenyl group, or an alkynyl group, and good characteristics It is preferable because it can be obtained.

Moreover, the burn-in characteristic can be improved by using the diamine containing a heterocyclic compound, a nitrogen atom, a sulfur atom, etc. An example of the preferable structure is shown below.

[Formula 11]

[Formula 12]

Moreover, when aiming at the improvement of the mechanical strength of a liquid crystal aligning film, the improvement of long-term reliability, a soluble improvement, etc., combined use of the diamine which has a functional group of a side chain type as shown below is preferable.

[Formula 13]

[Formula 14]

The tetracarboxylic dianhydride used for the synthesis|combination of a polyamic acid and a soluble polyimide is represented by following formula (4).

[Formula 15]

X is a tetravalent organic group, and the structure is not specifically limited.

There is no restriction|limiting in particular in the kind of tetracarboxylic dianhydride used for this invention, According to characteristics, such as the liquid-crystal orientation when it is set as a liquid crystal aligning film, a pretilt angle, a voltage holding characteristic, a stored electric charge, 1 type or 2 types or more can be used together.

Although the example of specific X is shown below, it is not limited to these structures.

[Formula 16]

[Formula 17]

[Formula 18]

Among the structures described above, from the viewpoint of solubility, alicyclic tetracarboxylic dianhydride as represented by X-1 to 26 is preferable, and X-2, X-3, X-4, X-6, X- 9, X-10, X-11, X-12, X-13, X-14, X-15, X-16, X-17, X-18, X-19, X-20, X-21, X-22, X-23, X-24, X-25, X-26 are preferred. On the other hand, from a viewpoint of orientation, aromatic tetracarboxylic dianhydride like X-27-46 is preferable, and especially X-27, X-28, X-33, X-34, X-35, X-40, X -41, X-42, X-43, X-44, X-45, X-46 are preferable.

Especially preferably, they are X-1, X-2, X-18-22, X-25, and X-26 which have orientation and solubility moderately.

<Polyamic acid>

Since the polyamic acid used for the liquid crystal aligning agent of this invention plays the role which discharge|releases the residual electric charge (henceforth, it denotes as RDC) rapidly which generate|occur|produces in a liquid crystal aligning film, it is represented by Formula (iii)-(vi) as a raw material It is characterized in that at least one compound is used. The tetracarboxylic dianhydride represented by Formula (iii) - (v) may be used independently and may be used in combination. Moreover, when using the diamine represented by Formula (vi), discharge|release of further RDC can be accelerated|stimulated by using together tetracarboxylic dianhydride represented by (iii)-(v). On the other hand, even if it combines with aliphatic tetracarboxylic dianhydride, since there exists the discharge|release ability of the outstanding RDC only by the diamine of Formula (vi), a favorable characteristic is acquired.

[Formula 19]

20 mol% - 100 mol% are preferable with respect to the whole tetracarboxylic dianhydride used for the synthesis|combination of the polyamic acid used by (iii)-(v) as for tetracarboxylic dianhydride, 40 mol% - 100 mol% are more preferable. Moreover, 20 mol% - 100 mol% are preferable with respect to the whole diamine component used for the synthesis|combination of the polyamic acid used by this invention, and, as for the diamine represented by Formula (vi), 40 % - 90 % are more preferable.

The polyamic acid used by this invention may use together the diamine and tetracarboxylic dianhydride mentioned above other than the at least 1 sort(s) of compound chosen from the compound of Formula (iii)-(vi), Formula (i) and (ii) may be used. Moreover, you may use side chain diamine as shown to Y-112-143 below as needed.

[Formula 20]

[Formula 21]

Among Y-112 to Y-116, A ₁ is an alkyl group having 2 to 24 carbon atoms or a fluorine-containing alkyl group.

[Formula 22]

In formulas Y-117 to Y-118, A ₂ represents -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -, or -CH ₂ OCO-, and A ₃ represents 1 to 22 carbon atoms. of an alkyl group, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.

[Formula 23]

In formulas Y-119 to Y-121, A ₄ is -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ - or -CH ₂ - is represented, and A ₅ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group.

[Formula 24]

In formulas Y-122 to Y-123, A ₆ is -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ represents -, -CH ₂ -, -O-, or -NH-, and A ₇ is a fluorine group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, or a hydroxyl group to be.

[Formula 25]

In Y-124 and formula Y-125, A ₈ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer, respectively.

[Formula 26]

In formulas Y-126 and Y-127, A ₉ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer, respectively.

[Formula 27]

[Formula 28]

In formula [Y-136] - formula [Y-141], A ₁₂ is -COO-, -OCO-, -CONH-, -NHCO-, -CH ₂ -, -O-, -CO-, or - NH- is represented, and A ₁₃ is a C1-C22 alkyl group or a fluorine-containing alkyl group.

[Formula 29]

<Production of soluble polyimide and polyamic acid>

When manufacturing the polyimide used for this invention, the weight average molecular weight of the polyamic acid which is a precursor of a polyimide becomes like this. Preferably it is 10,000-305,000, More preferably, it is 20,000-210,000. Moreover, the number average molecular weight becomes like this. Preferably it is 5,000-152,500, More preferably, it is 10,000-105,000.

The soluble polyimide and polyamic acid contained in the liquid crystal aligning agent of this invention are manufactured as follows. In addition, although a soluble polyimide is obtained by imidating the polyamic acid which is the precursor, the difference between the polyamic acid which is a precursor of a soluble polyimide, and the polyamic acid mixed with a soluble polyimide, the former is the diamine component used as the raw material It consists in using a specific diamine as

The polyamic acid which is mixed with a soluble polyimide, and the polyamic acid which is a precursor of a soluble polyimide are all manufactured by polycondensing a diamine component and tetracarboxylic dianhydride component in an organic solvent.

As a method of polycondensing a tetracarboxylic dianhydride component and a diamine component in an organic solvent, the solution which disperse|distributed or melt|dissolved the diamine component in the organic solvent is stirred, and tetracarboxylic dianhydride component is directly or in an organic solvent. A method of adding by dispersing or dissolving, conversely, a method of adding a diamine component to a solution obtained by dispersing or dissolving a tetracarboxylic dianhydride component in an organic solvent, a method of alternately adding a tetracarboxylic dianhydride component and a diamine component can be heard Moreover, when a tetracarboxylic dianhydride component or a diamine component consists of multiple types of compounds, you may make it polycondensation-react in the state which mixed these multiple types of compound previously, and you may make it polycondensation-react individually sequentially.

The temperature at the time of making polycondensation reaction of a tetracarboxylic dianhydride component and a diamine component in an organic solvent is 0-150 degreeC normally, Preferably it is 5-100 degreeC, More preferably, it is 10-80 degreeC. The higher the temperature, the faster the polycondensation reaction is finished, but when the temperature is too high, the polymer having a high molecular weight may not be obtained.

Moreover, although polycondensation reaction can be performed at arbitrary density|concentrations, when a density|concentration is too low, it will become difficult to obtain a high molecular weight polymer, When the density|concentration of the total mass of a tetracarboxylic dianhydride component and a diamine component is too high, Since the viscosity of the reaction liquid becomes too high and uniform stirring becomes difficult, Preferably it is 1-50 mass %, More preferably, it is 5-30 mass %. The initial stage of the polycondensation reaction may be performed at a high concentration, and an organic solvent may be added thereafter.

The organic solvent used at the time of the said reaction will not be specifically limited if the produced|generated polyamic acid melt|dissolves. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and 1,3-dimethylimidazolidone. dione, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethyl phosphate triamide, γ-butyrolactone, and the like. These may be used individually or in mixture. Moreover, even if it is a solvent in which a polyamic acid is not dissolved, you may use it in the range in which the produced|generated polyamic acid does not precipitate, mixing with the said solvent.

Moreover, since the water|moisture content in an organic solvent inhibits a polycondensation reaction, and becomes a cause which hydrolyzes the produced|generated polyamic acid by extension, it is preferable to use the thing which dehydrated and dried as much as possible as an organic solvent.

It is preferable that the ratio of the tetracarboxylic dianhydride component and diamine component used for the polycondensation reaction of a polyamic acid is 1:0.8-1:1.2 by molar ratio, and it is so close to this molar ratio 1:1 of the polyamic acid obtained molecular weight increases.

A polyamic acid is manufactured as mentioned above, and the polyamic acid mixed with a soluble polyimide is used as 1 component of the liquid crystal aligning agent of this invention. On the other hand, polyamic acid which is a precursor of a soluble polyimide is imidated. In an organic solvent, imidation of a polyamic acid is preferably performed by stirring preferably in presence of a basic catalyst and an acid anhydride for 1 to 100 hours.

Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine is preferable because it has suitable basicity to advance the reaction.

Moreover, acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. are mentioned as an acid anhydride. Among these, acetic anhydride is preferable after imidation, since purification of the obtained polyimide becomes easy. As an organic solvent, the solvent used at the time of the polycondensation reaction of the above-mentioned polyamic acid can be used.

The imidation rate of a soluble polyimide is controllable by adjusting a catalyst amount, reaction temperature, and reaction time. As for the quantity of the basic catalyst at this time, 0.2-10 times mole of an amic-acid group is preferable, More preferably, it is 0.5-5 times mole. Moreover, as for the quantity of an acid anhydride, 1-30 times mole of an amic acid group is preferable, More preferably, it is 1-10 times mole. As for reaction temperature, -20-250 degreeC is preferable, More preferably, it is 0-180 degreeC. Reaction time becomes like this. Preferably it is 1 to 100 hours, More preferably, it is 1 to 20 hours.

Although the imidation ratio of a soluble polyimide is not specifically limited, It is preferable that it is 40 % or more, In order to obtain a high voltage retention, 60 % or more is preferable, More preferably, it is 80 % or more. Since the added catalyst etc. remain|survive in the solution of the obtained soluble polyimide, after collect|recovering and washing|cleaning a soluble polyimide, it is preferable to use for the liquid crystal aligning agent of this invention.

Recovery of a soluble polyimide is possible by injecting|throwing-in the solution after imidation to the stirring poor solvent, and filtering, after depositing a polyimide. Examples of the poor solvent at this time include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene. Washing of the collect|recovered soluble polyimide can also be performed with this poor solvent.

Thus, the polyimide collect|recovered and washed can be made into powder by normal temperature or heat-drying under normal pressure or reduced pressure.

<Liquid crystal aligning agent>

The liquid crystal aligning agent of this invention contains said soluble polyimide and polyamic acid in the form which melt|dissolved in the organic solvent. To a liquid crystal aligning agent, a soluble polyimide becomes like this. Preferably it is 3-10 mass %, More preferably, 4-7 mass % is contained. Moreover, in a liquid crystal aligning agent, a polyamic acid becomes like this. Preferably it is 3-10 mass %, More preferably, 4-7 mass % is contained. Content of the sum total of the soluble polyimide and polyamic acid in a liquid crystal aligning agent becomes like this. Preferably it is 3-10 mass %, More preferably, 4-7 mass % is contained.

Moreover, in a liquid crystal aligning agent, with respect to 100 mass parts of soluble polyimides, the said polyamic acid becomes like this. Preferably it is 10-1000 mass parts, More preferably, 10-800 mass parts contains.

The organic solvent contained in a liquid crystal aligning agent becomes like this. Preferably it is 90-97 mass %, It is good that it is 93-96 mass % more preferably.

Liquid crystal aligning agent of this invention WHEREIN: As an organic solvent used for melt|dissolving a soluble polyimide and a polyamic acid, the organic solvent (solvent) used for the liquid crystal aligning agent of this invention is the organic solvent in which a polymer component is dissolved. If it is, it will not specifically limit. The specific example is given below.

N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone Don, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, γ-butyrolactone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-part Toxy-N,N-dimethylpropanamide, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate , propylene carbonate, diglyme, 4-hydroxy-4-methyl-2-pentanone, and the like. These may be used independently and may be mixed and used for them.

The liquid crystal aligning agent of this invention may contain components other than said polymer component. As the example, the solvent and compound which improve the film-thickness uniformity and surface smoothness at the time of apply|coating a liquid crystal aligning agent, the compound etc. which improve the adhesiveness of a liquid crystal aligning film and a board|substrate.

The following are mentioned as a specific example of the solvent (poor solvent) which improves the uniformity of a film thickness and surface smoothness.

For example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl Carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, propylene glycol mono Butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoethyl ether Propylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol , diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1-hexanol, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, 3-methoxymethyl propionate, 3 -Methylethyl ethoxypropionate, 3-methoxyethyl propionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl, 3-methoxybutyl propionate, 1-methoxy-2-propanol, 1 -Ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene Glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, lactic acid methyl ester, lactic acid ethyl ester, lactic acid n-propyl ester, lactic acid n-butyl ester, lactic acid Soma mil ester, etc. The solvent etc. which have a low surface tension are mentioned.

Even if these poor solvents are one type, you may mix and use multiple types. When using the above solvents, it is preferable that it is 5-80 mass % of the whole solvent contained in a liquid crystal aligning agent, More preferably, it is 20-60 mass %.

As a compound which improves the uniformity of a film thickness and surface smoothness, a fluorochemical surfactant, silicone type surfactant, nonionic surfactant, etc. are mentioned.

More specifically, for example, FTOP EF301, EF303, EF352 (manufactured by Tochem Products), Megapack F171, F173, R-30 (manufactured by Dainippon Ink, Inc.), Fluorad FC430, FC431 (Sumitomo 3M Corporation) manufacture), AsahiGuard AG710, Sufflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (made by Asahi Glass Corporation), etc. are mentioned. To [ the usage ratio of these surfactant / 100 mass parts of resin components contained in a liquid crystal aligning agent ], Preferably it is 0.01-2 mass parts, More preferably, it is 0.01-1 mass part.

As a specific example of the compound which improves the adhesiveness of a liquid crystal aligning film and a board|substrate, the functional silane containing compound shown next, an epoxy group containing compound, etc. are mentioned.

For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3 -aminopropyltrimethoxysilane,

N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureapropyltrimethoxysilane, 3-ureidepropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltri Methoxysilane, 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-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N -Phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltriethoxysilane, ethylene glycol digly Cydyl 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-dibroneopentyl 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, N,N,N', N',-tetraglycidyl-4,4'-diaminodiphenylmethane etc. are mentioned.

In addition to improving the adhesion between the substrate and the film, the following phenoplast-based additives, blocked isocyanates, hydroxyethylamide-based crosslinking agents, and the like may be introduced for the purpose of further preventing deterioration of electrical properties due to backlight. Although a specific additive is shown below, it is not limited to this structure.

[Formula 30]

[Formula 31]

When using the compound which improves adhesiveness with a board|substrate, it is preferable that the usage-amount is 0.1-30 mass parts with respect to 100 mass parts of the polymer component contained in a liquid crystal aligning agent, More preferably, it is 1-20 mass parts . When the usage-amount is less than 0.1 mass part, the effect of an adhesive improvement cannot be anticipated, and when it increases more than 30 mass parts, the liquid-crystal orientation may worsen.

In the liquid crystal aligning agent of this invention, if it is a range in which the effect of this invention is not impaired other than the above, for the purpose of changing electrical properties, such as dielectric constant and electroconductivity of a liquid crystal aligning film, a dielectric material and an electrically-conductive material, furthermore, it was made into a liquid crystal aligning film You may add the crosslinking|crosslinked compound for the purpose of raising the hardness and density of the film|membrane at the time of it.

<Liquid crystal alignment film, liquid crystal display element>

After apply|coating and baking the liquid crystal aligning agent of this invention on a board|substrate etc., it can orientation-process by rubbing process, light irradiation, etc., or can be used as a liquid crystal aligning film without an orientation process for a vertical alignment use etc. At this time, it will not specifically limit as a board|substrate used as long as it is a board|substrate with high transparency, A glass substrate, plastic substrates, such as an acryl substrate and a polycarbonate board|substrate, etc. can be used. Moreover, it is preferable from a viewpoint of simplification of a process to use the board|substrate with which the ITO (Indium Tin Oxide) electrode etc. for a liquid crystal drive were formed. In the reflective liquid crystal display element, an opaque material such as a silicon wafer can be used only on one side of the substrate, and in this case, a light-reflecting material such as aluminum can also be used for the electrode.

Although the application method of a liquid crystal aligning agent is not specifically limited, Industrially, the method of performing by screen printing, offset printing, flexographic printing, inkjet, etc. is common. As another coating method, there exist a dip, a roll coater, a slit coater, a spinner, etc., You may use these according to the objective. Since the solubility to the solvent of the polymer obtained using the diamine represented by Formula (1) and (2) to contain is favorable, the liquid crystal aligning agent of this invention is excellent in printability. Accordingly, when applied to a substrate or the like, precipitation and whitening (ie, generation of aggregates) are suppressed, and coating and film-forming properties are improved. Moreover, even if it lengthens the leaving time after apply|coating to a board|substrate etc., the liquid crystal aligning film excellent in uniformity and transparency can be manufactured.

Baking after apply|coating a liquid crystal aligning agent on a board|substrate is 50-300 degreeC with heating means, such as a hotplate, Preferably it is 80-250 degreeC, a solvent can be evaporated and a coating film can be formed. By this baking, the organic group A which can detach|desorb by the heat|fever derived from the diamine shown by Formula (1) and (2) detach|desorbs from a polyamic acid, polyamic acid ester, a polyimide, and a polyamide, and said cyclization reaction However, it is consumed in intermolecular reactions. Therefore, the liquid crystal aligning film obtained does not occur easily film cutting at the time of a rubbing process, is excellent in rubbing tolerance, and although it exposes to a backlight for a long period of high temperature, high humidity, the fall of voltage retention becomes difficult to occur. Moreover, it is estimated that the structure of the polymer after baking changes to the structure close|similar to a liquid crystal by cyclization reaction, Therefore, favorable liquid-crystal orientation is shown.

When the thickness of the coating film formed after firing is too thick, it becomes disadvantageous in terms of power consumption of the liquid crystal display element, and when it is too thin, the reliability of the liquid crystal display element may decrease, so preferably 5 to 300 nm, more Preferably it is 10-100 nm. When a liquid crystal is horizontally orientated horizontally or diagonally, the coating film after baking is processed by rubbing, polarization|polarized-light ultraviolet irradiation, etc.

After obtaining the board|substrate with a liquid crystal aligning film from the liquid crystal aligning agent of this invention by the above-mentioned method, the liquid crystal display element of this invention manufactures a liquid crystal cell by a well-known method, and sets it as a liquid crystal display element. For example, a liquid crystal cell comprising two substrates arranged to face each other, a liquid crystal layer formed between the substrates, and a liquid crystal cell having the liquid crystal aligning film formed between the substrate and the liquid crystal layer and formed by the liquid crystal aligning agent of the present invention display element. As a liquid crystal cell manufacturing method, a pair of board|substrates in which the liquid crystal aligning film was formed are prepared, a spacer is spread|dispersed on the liquid crystal aligning film of one board|substrate, a liquid crystal aligning film surface is made inside, and the other board|substrate is bonded together. ), the method of injecting a liquid crystal under reduced pressure and sealing, or the method of bonding a board|substrate and sealing after dripping a liquid crystal to the liquid crystal aligning film surface which disperse|distributed the spacer, etc. can be illustrated. The thickness of the spacer at this time is preferably 1 to 30 µm, more preferably 2 to 10 µm.

The liquid crystal includes a positive liquid crystal having positive dielectric anisotropy and a negative liquid crystal having negative dielectric anisotropy, specifically, for example, MLC-2003, MLC-2041, MLC manufactured by Merck Corporation. -6608, MLC-6609, etc. can be used.

As mentioned above, the liquid crystal display element manufactured using the liquid crystal aligning agent of this invention becomes the thing excellent in reliability, and can be used suitably for a high-definition liquid crystal television etc. with a large screen.

Example

Hereinafter, although an Example is given and this invention is demonstrated, it goes without saying that the present invention is not limited to these and interpreted.

The abbreviation of the compound used by an Example and a comparative example is as follows.

<Tetracarboxylic dianhydride>

A-1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride

A-2: 1,2,3,4-butanetetracarboxylic dianhydride

A-3: 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride

A-4: pyromellitic dianhydride

A-5: 3,3',4,4'-biphenyltetracarboxylic dianhydride

[Formula 32]

<Diamine>

B-1: 1,4-phenylenediamine

B-2: B-3: 4,4-diaminodiphenylmethane

B-3: 4,4'-diaminodiphenylamine

B-4: 3,5-diaminobenzoic acid

B-5: 1,2-bis(4-aminophenoxy)ethane

B-6: 1,5-bis(4-aminophenoxy)pentane

B-7: N1,N4-bis(2-tert-butoxycarbonylamino-4-aminophenyl)adipamide

B-8: 4-amino-N-(2-tert-butoxycarbonylamino-4-aminophenyl)benzamide

[Formula 33]

<Organic solvent>

NMP: N-methyl-2-pyrrolidone

GBL: γ-butyrolactone

BCS: Butyl Cellosolve

Below, the evaluation method implemented in this Example is shown.

<Viscosity measurement>

In the synthesis example or comparative synthesis example, the viscosity of the polyamic acid solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Industries, Ltd.), sample amount 1.1 ml, cone rotor TE-1 (1°34', R24), It measured at the temperature of 25 degreeC.

<Measurement of imidization rate>

The imidation ratio of polyimide was measured as follows. 20 mg of polyimide powder was put into the NMR sample tube, 0.53 ml of deuterated dimethyl sulfoxide (DMSO- _d6 , 0.05% TMS mixture) was added, and it was made to melt|dissolve completely. Proton NMR of 500 MHz was measured for this solution with the NMR measuring instrument (JNM-ECA500) by the Nippon Electronics Datum company.

The imidation rate was computed with the following formula|equation. In addition, the imidation rate of the polyimide which does not use the diamine represented by Formula (1) made zero the value of "introduction amount of the formula (1) diamine at the time of polyamic acid polymerization" in a following formula, and computed it.

Imidization rate (%) =

(100—Introduction amount of diamine (mol%)/2) x α of the formula (1) at the time of polymerization of polyamic acid

In the formula, α is determined using a proton derived from a structure that does not change before and after imidization as a reference proton, and the integrated peak value of this proton and the proton peak integrated value derived from the NH group of the amic acid appearing in the vicinity of 9.5 to 10.0 ppm. was obtained by the following equation using

α = (1 ― α·x/y)

In said formula, x is the proton peak integrated value derived from the NH group of an amic acid, y is the peak integrated value of a reference proton, α is the NH group of the amic acid in the case of a polyamic acid (imidation ratio is 0%) It is the ratio of the number of reference protons to one proton.

<Preparation of liquid crystal aligning agent>

Synthesis Example 1

Synthesis of A-3/B-1 (70), B-8 (30) Soluble Polyimide and Varnish Adjustment

In a 200 ml four-neck flask equipped with a nitrogen inlet tube and a mechanical stirrer, 2.27 g (20.98 mmol) of B-1 as a diamine component, and 5.00 g (8.99 mmol) of B-8 were weighed and placed, and NMP was added After adding 64.3 g, confirming that the diamine component is completely dissolved, adding 8.81 g (29.37 mmol) of A-3 while cooling in an ice bath, and stirring for 10 minutes, the temperature is raised to 50° C. until the viscosity is stabilized It was made to react, and a 20 mass % polyamic-acid solution [PAA-1] was obtained. The viscosity after stabilization was about 1500 mPa·s. In addition, the reaction was performed in nitrogen atmosphere.

60.0 g of the obtained polyamic-acid solution was transferred to a 300 ml bowl-shaped flask, 140.0 g of NMPs were added, and the 6.0 weight% solution was adjusted. After adding 11.41 g (111.76 mmol) of acetic anhydride and 8.84 g (111.76 mmol) of pyridine to this solution, and stirring at room temperature for 30 minutes, it heated up at 45 degreeC, and made it react for 3 hours.

After the reaction, this solution was slowly poured into 770 g of methanol cooled to 10 DEG C or lower to precipitate a solid. After collect|recovering solid by suction filtration and performing repulping twice with 500 g of methanol, the polyimide [SPI-1] of this invention was obtained by vacuum-drying at 60 degreeC. The imidation ratio was 84%.

2.00 g of SPI-1 was weighed and placed in a 50 ml Erlenmeyer flask equipped with a stirrer, 18.0 g of GBL was added, stirred at 50° C. for 24 hours to dissolve, and it was confirmed that it was completely dissolved, and 13.33 g of GBL was added, By stirring at room temperature for 30 minutes, the polyimide solution [SPI-1S] whose SPI-1 is 6.0 mass % and GBL is 94 mass % was obtained.

Synthesis Example 2

A-3/B-1 (70), B-9 (30) Synthesis of soluble polyimide and varnish adjustment

In a 100 ml 4-neck flask equipped with a nitrogen inlet tube and a mechanical stirrer, 2.95 g (27.29 mmol) of B-1 as a diamine component, 4.00 g (11.70 mmol) of B-9 were weighed and placed, and NMP was added After adding 73.64 g, confirming that the diamine component is completely dissolved, adding 11.46 g (38.21 mmol) of A-3 while cooling in an ice bath, and stirring for 10 minutes, the temperature is raised to 50° C. until the viscosity is stabilized. It was made to react, and a 20 mass % polyamic-acid solution [PAA-2] was obtained. The viscosity after stabilization was about 1300 mPa·s. In addition, the reaction was performed in nitrogen atmosphere.

70.0 g of the obtained polyamic-acid solution was transferred to a 300 mL spoon-type flask, 163.0 g of NMPs were added, and the 6.0 weight% solution was adjusted. To this solution, 15.12 g (148.10 mmol) of acetic anhydride and 11.72 g (148.10 mmol) of pyridine were added, and after stirring at room temperature for 30 minutes, the temperature was raised to 45° C. and reacted for 3 hours.

After the reaction, this solution was slowly poured into 800 g of methanol cooled to 10 DEG C or lower to precipitate a solid. After collect|recovering solid by suction filtration and performing repulping twice with 500 g of methanol, the polyimide [SPI-2] of this invention was obtained by vacuum-drying at 60 degreeC. The imidation ratio was 81 %.

2.00 g of SPI-2 was weighed and placed in a 50 ml Erlenmeyer flask equipped with a stirrer, 18.0 g of GBL was added, stirred at 50° C. for 24 hours to dissolve, confirmed that it was completely dissolved, and 13.33 g of GBL was added. And by stirring at room temperature for 30 minutes, the polyimide solution [SPI-2S] whose SPI-2 is 6.0 mass % and GBL is 94 mass % was obtained.

Synthesis Example 3

A-1, A-4 (50)/B-2 Polyamic acid polymerization and varnish adjustment

In a 200 ml four-necked flask equipped with a nitrogen inlet tube and a mechanical stirrer, 9.91 g (50.00 mmol) of B-2 is weighed and contained, and 56.04 g of NMP and 56.04 g of GBL are added and dissolved, and the temperature is about 10 ° C. Cool, weigh 4.41 g (22.50 mmol) of A-1, add little by little, add 5.45 g (25.00 mmol) of A-4 little by little, return to room temperature and react until the viscosity is stable, A 15 mass % polyamic-acid solution [PAA-3] was obtained. The viscosity after stabilization was about 350 mPa·s. In addition, the reaction was performed in nitrogen atmosphere.

100.0 g of the polyamic acid solution obtained above was weighed and placed in a 500 ml Erlenmeyer flask equipped with a stirrer, 23.33 g of γBL, 26.67 g of NMP, and 50.00 g of BCS were added, stirred at room temperature for 30 minutes, and PAA- 3 obtained the polyamic-acid solution [PAA-1S] whose 6.0 mass %, γBL, 59 mass %, NMP, 20 mass %, and BCS are 15 mass %.

Synthesis Example 4

A-1, A-3 (20)/B-2, B-3 (20) Polyamic acid polymerization and varnish adjustment

In a 200 ml four-necked flask equipped with a nitrogen inlet tube and a mechanical stirrer, 1.98 g (10.00 mmol) of B-2 and 8.40 g (40.00 mmol) of B-3 were weighed and contained, and 152.10 g of NMP was added. Dissolve, cool to about 10°C, add A-1:7.35 g (38.00 mmol) little by little, then add A-3: 3.00 g (10.00 mmol) little by little, return to room temperature to stabilize the viscosity It was made to react until it became possible, and a 15 mass % polyamic-acid solution [PAA-4] was obtained. The viscosity after stabilization was about 180 mPa·s. In addition, the reaction was performed in nitrogen atmosphere.

100.0 g of polyamic acid solution obtained above is weighed and contained in a 500 mL Erlenmeyer flask equipped with a stirrer, 60.00 g of NMP is added, 40 g and BCS are added, and it stirs at room temperature for 30 minutes, and PAA-3 6.0 mass % and NMP obtained the polyamic-acid solution [PAA-2S] whose 64 mass % and BCS are 30 mass %.

Synthesis Example 5

A-1, A-2 (65)/B-6, B-8 (30) Synthesis of soluble polyimide and varnish adjustment

In a 100 ml four-necked flask equipped with a nitrogen inlet tube and a mechanical stirrer, 6.84 g (28.00 mmol) of B-6 as a diamine component, 6.68 g (12.00 mmol) of B-8 were weighed, and NMP was added. After adding 57.60 g, confirming that the diamine component has completely dissolved, 5.15 g (26.00 mmol) of A-2 is added while cooling in an ice bath, and 2.26 g (11.50 mmol) of A-1 is added successively, NMP After adding 25.8g and stirring for 10 minutes, it heated up at 40 degreeC, it was made to react until a viscosity is stabilized, and the 20 mass % polyamic-acid solution [PAA-5] was obtained. The viscosity after stabilization was about 1200 mPa·s. In addition, the reaction was performed in nitrogen atmosphere.

40.0 g of the obtained polyamic-acid solution was transferred to a 200 mL spoon-type flask, 83.0 g of NMPs were added, and the 6.5 weight% solution was adjusted. 3.90 g (3.79 mmol) of acetic anhydride and 1.81 g (2.28 mmol) of pyridine were added to this solution, and it heated up at 50 degreeC, and was made to react for 2 hours.

After the reaction, this solution was slowly poured into 450 g of methanol cooled to 10 DEG C or lower to precipitate a solid. After collect|recovering solid by suction filtration and performing repulping twice with 200 g of methanol, the polyimide [SPI-3] of this invention was obtained by vacuum-drying at 60 degreeC. The imidation ratio was 65 %.

5.3 g of SPI-3 was weighed and placed in a 100 ml Erlenmeyer flask equipped with a stirrer, 19.4 g of NMP and 10.6 g of GBL were added, stirred at 50° C. for 20 hours to dissolve, and it was confirmed that the NMP was completely dissolved, 12.4 g of γBL, 14.1 g of γBL, and 20.6 g of BCS are added and stirred at room temperature for 30 minutes, whereby SPI-3 is 6.0 mass%, NMP is 39.0 mass%, GBL is 30.0 mass%, and BCS is 25.0 mass%. A mid solution [SPI-3S] was obtained.

Synthesis Example 6

A-1, A-5 (45)/B-3, B-6 (50) Polyamic acid polymerization and varnish adjustment

In a 100 ml four-neck flask equipped with a nitrogen inlet tube and a mechanical stirrer, 3.98 g (20.00 mmol) of B-3 and 4.88 g (20.00 mmol) of B-6 were weighed and contained, NMP was 32.50 g, GBL was dissolved by adding 32.50 g, cooled to about 10° C., weighed 3.68 g (18.80 mmol) of A-1, added little by little, added 13.50 g of NMP, 13.50 g of γBL, and stirred for 2 hours After adding 5.30 g (18.00 mmol) little by little for A-5 after that and adding 19.40 g of NMP and γBL 19.40 g, it is made to react at 40 degreeC until a viscosity is stabilized, and a 12 mass % polyamic acid A solution [PAA-6] was obtained. The viscosity after stabilization was about 270 mPa·s. In addition, the reaction was performed in nitrogen atmosphere.

40.0 g of the polyamic acid solution obtained above was weighed and placed in a 100 ml Erlenmeyer flask equipped with a stirrer, 23.33 g of γBL, 26.67 g of NMP, and 20.00 g of BCS were added, stirred at room temperature for 30 minutes, and PAA- 3 6.0 mass %, γBL 30.0 mass %, NMP 39.0 mass %, BCS obtained the polyamic-acid solution [PAA-3S] whose 25.0 mass % is.

Synthesis Example 7

A-5/B-3, B-5 (20) Polyamic acid polymerization and varnish adjustment

In a 200 ml four-necked flask equipped with a nitrogen inlet tube and a mechanical stirrer, 8.21 g (41.20 mmol) of B-3 and 15.60 g (10.30 mmol) of B-5 were weighed and contained, NMP was 69.5 g, GBL was dissolved by adding 69.5 g, cooled to about 10 ° C., weighed 13.90 g (47.20 mmol) of A-5, added little by little, 17.4 g of NMP, and 17.4 g of γBL After adding and stirring for a while , it was made to react at 40 degreeC until a viscosity is stabilized, and the 12 mass % polyamic-acid solution [PAA-7] was obtained. The viscosity after stabilization was about 300 mPa·s. In addition, the reaction was performed in nitrogen atmosphere.

40.0 g of the polyamic acid solution obtained above was weighed and placed in a 100 ml Erlenmeyer flask equipped with a stirrer, 23.33 g of γBL, 26.67 g of NMP, and 20.00 g of BCS were added, stirred at room temperature for 30 minutes, and PAA- 3 obtained the polyamic-acid solution [PAA-4S] whose 6.0 mass %, NMP is 39.0 mass %, γBL is 30.0 mass %, and BCS is 25.0 mass %.

Synthesis Example 8

Synthesis of A-3/B-6 Soluble Polyimide and Varnish Adjustment

In a 100 ml 4-neck flask equipped with a nitrogen inlet tube and a mechanical stirrer, 5.00 g (20.47 mmol) of B-6 as a diamine component was weighed and contained, 44.6 g of NMP was added, and the diamine component was completely dissolved. After confirming, adding 6.14 g (20.47 mmol) of A-3 and stirring for 10 minutes, cooling in an ice bath, it is made to react until it heats up at 50 degreeC and a viscosity becomes stable, and a 20 mass % polyamic acid solution [PAA -4] was obtained. The viscosity after stabilization was about 1100 mPa·s. In addition, the reaction was performed in nitrogen atmosphere.

30.0 g of the obtained polyamic-acid solution was transferred to a 200 mL spoon-type flask, 60.0 g of NMPs were added, and the 6.0 weight% solution was adjusted. After adding 5.60 g (55.13 mmol) of acetic anhydride and 4.36 g (55.13 mmol) of pyridine to this solution, and stirring at room temperature for 30 minutes, it heated up at 40 degreeC, and made it react for 3 hours.

After the reaction, this solution was slowly poured into 350 g of methanol cooled to 10 DEG C or lower to precipitate a solid. After collect|recovering solid by suction filtration and performing repulping twice with 200 g of methanol, the polyimide [SPI-4] of a comparison object was obtained by vacuum-drying at 60 degreeC. The imidation rate was 63 %.

2.00 g of SPI-4 is weighed and placed in a 50 ml Erlenmeyer flask equipped with a stirrer, 18.0 g of GBL is added, stirred at 50° C. for 24 hours to dissolve, confirming that it is completely dissolved, and 13.33 g of GBL is added, By stirring at room temperature for 30 minutes, the polyimide solution [SPI-4S] whose SPI-4 is 6.0 mass % and GBL is 94 mass % was obtained.

Synthesis Example 9

A-4/B-7 Polyamic acid polymerization and varnish adjustment

In a 200 ml four-necked flask equipped with a nitrogen inlet tube and a mechanical stirrer, 5.00 g (17.46 mmol) of B-7 was weighed and contained, 56.67 g of NMP was added to dissolve, cooled to about 10° C., and A- 3.50 g (16.06 mmol) of 4 was weighed and contained, added little by little, returned to room temperature, it was made to react until a viscosity is stabilized, and 15 mass % polyamic-acid solution [PAA-5] was obtained. The viscosity after stabilization was about 420 mPa·s. In addition, the reaction was performed in nitrogen atmosphere. The number average molecular weight of 12,500 and the weight average molecular weight of obtained PAA-5 were 33800.

50.0 g of the polyamic acid solution obtained above is weighed and placed in a 500 ml Erlenmeyer flask equipped with a stirrer, 11.67 g of γBL, 13.34 g of NMP, and 25.00 g of BCS are added, stirred at room temperature for 30 minutes, and PAA- The polyamic-acid solution [PAA-5S] whose tetravalent 6.0 mass %, NMP is 20 mass %, and BCS is 15 mass % was obtained.

Example 1

Adjustment of liquid crystal aligning agent -1 [SPI-1S/PAA-1S 30:70 (weight ratio)] and evaluation of liquid crystal aligning film

In a 100 ml Erlenmeyer flask equipped with a stirrer, 30.0 g of SPI-1S obtained by the method of Synthesis Example 1 and 70.0 g of PAA-1S obtained by the method of Synthesis Example 3 were weighed and placed, followed by stirring under a nitrogen atmosphere for 20 hours. Then, the liquid crystal aligning agent -1 of this invention was obtained by pressure-filtration with the membrane filter of 1 micrometer of pore diameters.

Example 2

Adjustment of liquid crystal aligning agent-2 [SPI-2S/PAA-2S 30:70 (weight ratio)] and evaluation of liquid crystal aligning film

In a 100 ml Erlenmeyer flask equipped with a stirrer, 30.0 g of SPI-2S obtained by the method of Synthesis Example 2 and 70.0 g of PAA-2S obtained by the method of Synthesis Example 4 were weighed and placed, followed by stirring under a nitrogen atmosphere for 20 hours. Then, the liquid crystal aligning agent -2 of this invention was obtained by pressure-filtration with the membrane filter of 1 micrometer of pore diameters.

Example 3

Adjustment of liquid crystal aligning agent-3 [SPI-3s/PAA-3s 30:70 (weight ratio)] and liquid crystal aligning film evaluation

In a 100 ml Erlenmeyer flask equipped with a stirrer, 30.0 g of SPI-3S obtained by the method of Synthesis Example 5 and 70.0 g of PAA-3S obtained by the method of Synthesis Example 6 were weighed and placed, followed by stirring under a nitrogen atmosphere for 20 hours. Then, the liquid crystal aligning agent -3 of this invention was obtained by pressure-filtration with the membrane filter of 1 micrometer of pore diameters.

Example 4

Adjustment of liquid crystal aligning agent -4 [SPI-3s/PAA-4s 30:70 (weight ratio)] and evaluation of liquid crystal aligning film

In a 100 ml Erlenmeyer flask equipped with a stirrer, 30.0 g of SPI-3S obtained by the method of Synthesis Example 5 and 70.0 g of PAA-4S obtained by the method of Synthesis Example 7 were weighed and placed, followed by stirring under a nitrogen atmosphere for 20 hours. Then, the liquid crystal aligning agent -4 of this invention was obtained by carrying out pressure filtration with the membrane filter of 1 micrometer of pore diameters.

Comparative Example 1

Adjustment of liquid crystal aligning agent-5 [SPI-4s/PAA-3s 30:70 (weight ratio)] and evaluation of liquid crystal aligning film

In a 100 ml Erlenmeyer flask equipped with a stirrer, 30.0 g of SPI-4S obtained by the method of Synthesis Example 8 and 70.0 g of PAA-3S obtained by the method of Synthesis Example 6 were weighed and placed, followed by stirring under a nitrogen atmosphere for 20 hours. Then, the liquid crystal aligning agent -5 used as a comparison object was obtained by carrying out pressure filtration with the membrane filter of 1 micrometer of pore diameters.

Comparative Example 2

Adjustment of liquid crystal aligning agent-6 [PAA-5s/PAA-2s 20:80 (weight ratio)] and liquid crystal aligning film evaluation

In a 100 ml Erlenmeyer flask equipped with a stirrer, 20.0 g of PAA-5S obtained by the method of Synthesis Example 9 and 80.0 g of PAA-2S obtained by the method of Synthesis Example 4 were weighed and placed, followed by stirring under a nitrogen atmosphere for 20 hours. Then, the liquid crystal aligning agent-6 used as a comparison object was obtained by carrying out pressure filtration with the membrane filter of 1 micrometer of pore diameters.

Using the liquid crystal aligning agent obtained in Examples 1-4 and Comparative Examples 1-2, the liquid crystal aligning film was evaluated based on the following method.

<Evaluation of film uniformity of orientation agent>

After filtering the liquid crystal aligning agent with a filter of 1.0 µm, a substrate with an electrode (a glass substrate having a size of 30 mm in width × 40 mm in length and 1.1 mm in thickness. The electrode is a rectangle having a width of 10 mm × length 40 mm and , an ITO electrode having a thickness of 35 nm) was applied by spin coating. After spin coating, the film was left to stand for 5 minutes at a room temperature of 23°C and a humidity of 50%, and baked in an IR oven at 220°C for 20 minutes. Analysis was performed, roughness per 10 μm was calculated and comparisons were made. It means that the uniformity and film-forming property of a film|membrane are so favorable that the roughness is small.

<Evaluation of backlight tolerance of voltage retention>

The backlight tolerance of voltage retention was evaluated as follows.

[Production of liquid crystal cell for voltage retention measurement]

After filtering the liquid crystal aligning agent with a filter of 1.0 μm, a substrate with an electrode (a glass substrate having a size of 30 mm in width × 40 mm in length and 1.1 mm in thickness. The electrode is a rectangle having a width of 10 mm × length 40 mm and , an ITO electrode having a thickness of 35 nm) was applied by spin coating. After drying for 5 minutes on a 50 degreeC hotplate, 230 degreeC IR type oven performed baking for 20 minutes, the coating film with a film thickness of 100 nm was formed, and the board|substrate with a liquid crystal aligning film was obtained. After rubbing this liquid crystal aligning film with rayon cloth (YA-20R manufactured by Yoshikawa Chemical) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm/sec, pushing length: 0.4 mm), in pure water After performing ultrasonic irradiation for 1 minute, washing|cleaning and removing water droplets by air blow, it was made to dry at 80 degreeC for 15 minutes, and the board|substrate with a liquid crystal aligning film was obtained.

After preparing two board|substrates with said liquid crystal aligning film and dispersing a 4 micrometers spacer on the liquid crystal aligning film surface of 1 sheet, a sealing compound is printed from it, and the rubbing direction of another board|substrate is After bonding in the reverse direction and with the film surfaces facing each other, the sealing compound was cured to prepare an empty cell. Negative liquid crystal MLC-7206 (manufactured by Merck Corporation) and MLC-2041 (manufactured by Merck Corporation) were injected into this empty cell by the reduced pressure injection method, the injection port was sealed, and the liquid crystal cell was obtained. Then, the obtained liquid crystal cell was heated at 110 degreeC for 1 hour, it was left to stand at 23 degreeC overnight, and the liquid crystal cell for a voltage retention measurement was obtained.

[Evaluation of backlight tolerance]

The voltage of 1V was applied to said liquid crystal cell for voltage retention measurement 60 microseconds under the temperature of 60 degreeC, the voltage 100 msec after was measured, and how much voltage is maintained was computed as voltage retention. Let this be the initial voltage retention rate.

Next, as a backlight tolerance test, this liquid crystal cell was left to stand under the temperature of 70 degreeC, and an LED light source (1000 cd) for 72 hours. The voltage retention of this liquid crystal cell was measured similarly to the above. Let this be the voltage retention rate after the immunity test.

The backlight tolerance of voltage retention was evaluated by the magnitude of the voltage retention measured as mentioned above. That is, if the amount of change in the voltage retention after the tolerance test is small compared with the initial voltage retention, it means that the backlight tolerance is good.

[Mitigation characteristics of RDC]

The above-described liquid crystal cell for measuring voltage retention is provided between two polarizing plates arranged so that polarization axes are orthogonal to each other, and in a state where the pixel electrode and the counter electrode are short-circuited to the same potential, LED from under the two polarizing plates The backlight was irradiated, and the angle of the liquid crystal cell was adjusted so that the brightness|luminance of the LED backlight transmitted light measured on two polarizing plates might become the minimum.

Next, applying a square wave with a frequency of 30 Hz to this liquid crystal cell, the V-T characteristic (voltage-transmittance characteristic) under the temperature of 23 degreeC was measured, and the relative transmittance computed the alternating voltage used as 23 %. Since this AC voltage corresponds to a region where the change in luminance with respect to voltage is large, it is suitable for evaluating RDC through luminance.

Next, the DC voltage of +3.0V was superimposed, and it was made to drive for 1 hour, applying a square wave with a frequency of 30 Hz with the alternating voltage used as 23 % of a relative transmittance|permeability. Thereafter, the DC voltage was cut off, and only a square wave having a frequency of 30 Hz was applied for 30 minutes at an AC voltage having a relative transmittance of 23% again, and the recovery time of the flicker (flicker) generated at this time was measured.

The faster the relaxation of the accumulated charge and the shorter this time, the better the relaxation characteristics of the RDC.

Incidentally, the calculation of the flicker intensity can be performed by converting the luminance into a DC voltage using a photodiode and an AC-DC converter, and reading this with an oscilloscope. When the flicker occurs, it is monitored as an AC voltage correlated to a square wave of 30 Hz, so the time for this AC voltage to become a DC can be regarded as the relaxation time of RDC.

Since it cannot evaluate in MLC-7206 which is a driving phase of a liquid crystal, which is a negative liquid crystal, it implemented using MLC-2041 for this measurement.

<Evaluation of liquid crystal orientation>

Evaluation of the liquid-crystal orientation was evaluated as follows.

[Preparation of substrate with electrode for FFS method]

A substrate with an electrode for FFS method was prepared. The substrate is a glass substrate having a size of 30 mm × 35 mm and a thickness of 0.7 mm. On the board|substrate, the IZO electrode which comprises a counter electrode as a 1st layer is formed in the whole surface. On the IZO electrode of the 1st layer, the SiN (silicon nitride) film|membrane formed into a film by the CVD method is formed as a 2nd layer. The SiN film of the second layer has a film thickness of 500 nm, and functions as an interlayer insulating film. On the SiN film of the 2nd layer, the comb-tooth-shaped pixel electrode formed by patterning the IZO film|membrane as 3rd layer is arrange|positioned, and two pixels of a 1st pixel and a 2nd pixel are formed. The size of each pixel is 10 mm long and about 5 mm wide. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the action of the SiN film of the second layer.

The pixel electrode of the 3rd layer has the comb-tooth-shaped shape comprised by arranging a plurality of "<"-shaped electrode elements in which the center part was bent. The width in the transverse direction of each electrode element is 3 µm, and the distance between the electrode elements is 6 µm. Since the pixel electrode forming each pixel is constituted by arranging a plurality of "<"-shaped electrode elements in which the central part is bent, the shape of each pixel is not a rectangular shape, but a thick, curved shape at the center part similarly to the electrode element. It has a shape resembling the "ど" character of the character. And each pixel is divided|segmented up and down with the bent part in the center as a boundary, and has the 1st area|region above and the 2nd area|region below the bending|flexion part.

Comparing the 1st area|region and the 2nd area|region of each pixel, the formation direction of the electrode element of the pixel electrode which comprises them differs. That is, based on the rubbing direction of the liquid crystal alignment layer to be described later, the electrode element of the pixel electrode is formed to form an angle of +10° (clockwise) in the first region of the pixel, and the electrode of the pixel electrode in the second region of the pixel The elements are formed to form an angle of -10° (counterclockwise). That is, in the first region and the second region of each pixel, the directions of the rotational operation (in-plane switching) in the substrate plane of the liquid crystal caused by the voltage application between the pixel electrode and the counter electrode are opposite to each other. is structured to be

<Manufacture of the liquid crystal cell for liquid-crystal orientation evaluation>

After filtering a liquid crystal aligning agent with a 1.0-micrometer filter, it apply|coated to the board|substrate with an electrode for said FFS system by spin coat application|coating. After drying for 100 second on a 100 degreeC hotplate, 230 degreeC hot-air circulation type oven performed baking for 20 minutes, and the polyimide film|membrane with a film thickness of 60 nm was obtained. Rubbing this polyimide film with rayon cloth (YA-20R manufactured by Yoshikawa Chemical) (Roller diameter: 120 mm, Roller rotation speed: 500 rpm, Moving speed: 30 mm/sec, Pushing length: 0.3 mm, Rubbing direction: 3rd layer 80° inclined direction with respect to the IZO comb electrode), followed by washing by ultrasonic irradiation for 1 minute in a 3/7 mixed solvent of isopropyl alcohol and pure water, removing water droplets by air blow, and then drying at 80 ° C. for 15 minutes It was made and the board|substrate with a liquid crystal aligning film was obtained.

Moreover, as a counter board|substrate, it has a columnar spacer with a height of 4 micrometers, also in the glass substrate in which ITO is formed in the back surface, it carried out similarly to the above, and formed a polyimide film, The liquid crystal aligning film to which the orientation process was given in the same order as the above. This adhered substrate was obtained.

The two substrates with the liquid crystal aligning film are set as one set, and the sealing agent is printed in the form that the liquid crystal injection hole is left on the substrate, and the other substrate is rubbed with the liquid crystal aligning film faces facing each other and the rubbing direction is antiparallel After bonding as much as possible, the sealing compound was hardened, and the empty cell with a cell gap of 4 micrometers was manufactured.

Negative liquid crystal MLC-7206 (manufactured by Merck Corporation) and MLC-2041 (manufactured by Merck Corporation) as a comparison object was adjusted by a reduced pressure injection method into this empty cell, the injection port was sealed, and the liquid crystal cell of the FFS system was got it Then, the obtained liquid crystal cell was heated at 110 degreeC for 30 minutes, it was left to stand at 23 degreeC overnight, and the liquid crystal cell for liquid-crystal orientation evaluation was obtained.

[Evaluation of liquid crystal orientation]

The alternating voltage used as 100% of relative transmittance|permeability was applied to said liquid crystal cell for liquid-crystal orientation evaluation in a 60 degreeC constant temperature environment at a frequency of 30 Hz for 168 hours. Then, it was set as the state made short between the pixel electrode of a liquid crystal cell, and a counter electrode, and it was left to stand at room temperature as it is for one day. After standing, the liquid crystal cell was installed between two polarizing plates arranged so that the polarization axes were orthogonal to each other, the backlight was turned on in a state where no voltage was applied, and the arrangement angle of the liquid crystal cell was adjusted so that the luminance of the transmitted light was the smallest. And the rotation angle when the liquid crystal cell was rotated from the angle at which the 2nd area|region of a 1st pixel becomes the darkest to the angle at which the 1st area|region becomes the darkest was computed as angle (triangle|delta). Similarly, in the second pixel, the second region and the first region were compared to calculate the same angle Δ. And the average value of the angle (triangle|delta) value of a 1st pixel and a 2nd pixel was computed as angle (triangle|delta) of a liquid crystal cell, and liquid-crystal orientation was evaluated by the magnitude of the value. That is, when the value of this angle (triangle|delta) is small, the liquid-crystal orientation is favorable.

※2 Measured using MLC-2041.

※3 After the flicker stops, the flicker occurs again.

By the liquid crystal aligning agent of this invention, application|coating and film-forming property is favorable, it is strong in film peeling and cutting at the time of rubbing, and even if a direct voltage is applied, it is hard to generate|occur|produce the initial charge accumulation|storage, and even if reliable liquid crystal is used, favorable reliability can be obtained, and a liquid crystal aligning film in which a decrease in voltage retention hardly occurs even when exposed to a backlight for a long period of time is obtained. Therefore, the liquid crystal display element manufactured using the liquid crystal aligning agent of this invention can be made into a highly reliable liquid crystal display element, TN liquid crystal display element, STN liquid crystal display element, TFT liquid crystal display element, VA liquid crystal display element, It is suitably used for the display element by various systems, such as an IPS liquid crystal display element and an OCB liquid crystal display element.

Claims (8)

The soluble polyimide obtained from the diamine component containing at least 1 sort(s) of diamine chosen from the diamine of following formula (i), (ii), and tetracarboxylic dianhydride component is contained, The liquid crystal aligning agent characterized by the above-mentioned.
[Formula 1]

In formula, D represents a divalent C1-C20 saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic ring, and D may have various substituents. E is a single bond, or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and F is a single bond or an ether bond (-O-), an ester bond (-OCO-, -COO-). m is 1 or 0. The method of claim 1,
Furthermore, the polyamic acid obtained using at least 1 type or more of the compound represented by Formula (iii) - (vi) is contained, The liquid crystal aligning agent characterized by the above-mentioned.
[Formula 2]

In formula (vi), R represents a hydrogen atom or a C1-C8 hydrocarbon group. The method of claim 1,
Liquid-crystal orientation whose said soluble polyimide is a soluble polyimide obtained from the diamine component containing 10-90 mol% of at least 1 sort(s) of diamine chosen from the diamine of Formula (i) and (ii), and tetracarboxylic dianhydride My. The method of claim 1,
The liquid crystal aligning agent whose imidation rate of the said soluble polyimide is 20 % - 100 %. The method of claim 1,
The liquid crystal aligning agent whose said soluble polyimide is a soluble polyimide obtained from the diamine component containing at least 1 or more types of diamine chosen from Formula (vii) - Formula (x), and tetracarboxylic dianhydride.
[Formula 3]

n represents an integer of 1 to 6, R ₃ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₄ is a linear alkylene group having 1 to 5 carbon atoms. 3. The method of claim 2,
The liquid crystal aligning agent which contains 1-10 mass % of the said soluble polyimide and the said polyamic acid in total, and ratio of the weight of the said polyimide and the weight of the said polyamic acid is 95:5-5:95. The liquid crystal aligning film obtained using the liquid crystal aligning agent in any one of Claims 1-6. The liquid crystal aligning film of Claim 7 was provided, The liquid crystal display element characterized by the above-mentioned.