TWI387622B - Liquid crystal aligning agent and liquid crystal display device - Google Patents

Description

Liquid crystal alignment agent and liquid crystal display element

The present invention relates to a polyaminic acid or a derivative thereof (may also be a composition containing two or more kinds of polyaminic acid or a derivative thereof). Further, the present invention relates to a liquid crystal display device comprising a liquid crystal alignment agent obtained by dissolving polyacrylic acid or a derivative thereof in a solvent, and a liquid crystal alignment film formed by the liquid crystal alignment agent.

Here, at least one of the above polyamic acid or a derivative thereof is obtained by reacting a specific diamine with tetracarboxylic dianhydride.

The liquid crystal display element is used in various liquid crystal display devices such as a viewfinder and a projection display of a camera represented by a screen of a laptop computer or a desktop computer, and has recently been used in televisions. Further, it can also be utilized as an optoelectronic related component such as an optical printer head, an optical Fourier transform element, or a light valve.

Conventional liquid crystal display elements are mainstream display elements using nematic liquid crystals, and the following liquid crystal display elements are put to practical use: 1) TN (twisted nematic) type liquid crystal display elements of 90 degree twist, 2) usually 180 A STN (super twisted nematic) type liquid crystal display element having a twisted degree or more, and a so-called TFT (thin film transistor) type liquid crystal display element having a thin film transistor.

These liquid crystal display elements have a drawback in that it is possible to visually confirm that the viewing angle of the image is narrow, and when viewed from the oblique direction, brightness or contrast is lowered and the brightness is reversed in the middle. In recent years, the problem of this viewing angle can be improved, put into practical use, or studied by the following techniques: 1) using a TN-TFT type liquid crystal display element having an optical compensation film, 2) using a VA having an optical compensation film (vertical alignment, vertical alignment) type display element, 3) MVA (multi-domain vertical alignment) type liquid crystal display element using vertical alignment and protrusion structure technology, or 4) transverse electric field mode IPS (in -plane switching, transverse electric field drive type liquid crystal display element, 5) ECB (electrically controlled birefringence) type liquid crystal display element, 6) optically compensated bend (optically compensated bend or optically self-compensated birefringence) Alignment or optical self-compensated birefringence: OCB) liquid crystal display elements and other technologies.

The development of liquid crystal display device technology can be achieved not only by the improvement of these driving methods or device structures, but also by the improvement of the components used for the display elements. Among the constituent members used for the display element, particularly the liquid crystal alignment film, which is one of the important factors related to the display quality of the liquid crystal display element, the role of the liquid crystal alignment film continues to become important as the display element is improved in quality.

The liquid crystal alignment film can be produced by a liquid crystal alignment agent. At present, a liquid crystal alignment agent mainly used refers to a solution in which a polyamic acid or a soluble polyimine is dissolved in an organic solvent. After applying such a solution to a substrate, a film is formed by a method such as adding a film to form a polyimide film. Various liquid crystal alignment agents other than polyglycolic acid have also been studied, but they are almost resistant to heat resistance, chemical resistance (liquid crystal resistance), coating properties, liquid crystal alignment, electrical properties, optical properties, display characteristics, and the like. Not practical.

In order to improve the display quality of the liquid crystal display element, a voltage holding ratio and a residual charge are exemplified as important characteristics required for the liquid crystal alignment film. When the voltage holding ratio is low, the voltage applied to the liquid crystal drops during the frame time, resulting in a decrease in luminance and hindering the normal harmonic display. On the other hand, when the residual charge is large, even if the voltage is turned off after the voltage is applied, an image having the erased image, that is, an "after image" remains.

As for attempts to solve the above problems, several methods have recently been proposed.

1) A polylysine composition having a composition containing two or more kinds of polyamic acid having different physical properties for forming a liquid crystal alignment film is known (refer to Japanese Patent Laid-Open No. Hei 11-193345 and Japanese Patent Laid-Open No. Hei 11-- Bulletin No. 193347).

2) A varnish composition comprising a polymer component containing polyamic acid and polyamine and a solvent is known (refer to Japanese Patent No. WO 00/61684).

3) A versatile composition containing two or more kinds of polyamic acid and polyamine and a solvent having different physical properties are known. (Refer to Japanese Patent No. WO 01/000733).

4) A versatile composition containing a polymer material containing polyglycolic acid or the like and a polyamine acid compound which is synthesized using an amine compound having a specific structure is known (refer to Japanese Laid-Open Patent Publication No. 2002-162630).

However, the above-described conventional techniques do not adequately solve the "after-image" problem caused by the large residual charge.

On the other hand, it is known that there is a liquid crystal display element device in which an alignment film is formed which suppresses deterioration of a light alignment film and contains a polyfluorene having an aromatic ring content of 0 to 30% by weight (% by weight). Imine (refer to Japanese Laid-Open Patent Publication No. 2001-42335). In this document, as for the polyimine having an aromatic ring content of 0 to 30% by weight, a polycondensation synthesized using 1,3-cyclohexane bis(methylamine) and m-phthaldimethyldiamine is exemplified. The proline acid is ruthenium imidized.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display element which can improve the problem of the above-mentioned "after-image" characteristics. Further, a liquid crystal alignment film which imparts desired afterimage characteristics to the liquid crystal display element, a polyamic acid having a function of a liquid crystal alignment agent for forming the liquid crystal alignment film, and a derivative thereof are also provided. And its composition.

The present inventors have diligently studied to solve the above problems.

As a result, it has been found that the above problem can be solved by a liquid crystal display element having a liquid crystal alignment film which is produced by using a liquid crystal alignment agent containing polylysine or a derivative thereof. It is obtained by reacting a diamine represented by the following general formula (I) or (I') with tetracarboxylic acid dianhydride.

Further, it has been found that a liquid crystal alignment film produced by using a liquid crystal alignment agent can impart desired image remnant characteristics to a liquid crystal display element, and the liquid crystal alignment agent includes a composition containing two or more kinds of polyaminic acid or a derivative thereof. And at least one of the compositions is polyamic acid A as described later.

In addition, it has been found that a liquid crystal alignment film produced by using a liquid crystal alignment agent containing the above composition can be suitably applied to liquid crystals of various display driving methods by appropriately selecting the type of polyamic acid combined with polyamic acid A. Display component.

(where n represents an integer of 1 or 2).

That is, the present invention has the following constitution.

[1] A composition comprising two or more kinds of polyaminic acid or a derivative thereof, comprising: A) polyglycine or a derivative thereof thereof, which is obtained by the following general formula (I) or The diamine A1 of the diamine (I') is reacted with the tetracarboxylic dianhydride A2; and B) the polyaminic acid or its derivative B, which is a diamine containing a side chain structure. The amine B1 is obtained by reacting with a tetracarboxylic dianhydride B2.

[2] The composition according to [1], wherein the diamine represented by the above general formula (I) or (I') is selected from the following structural formulae (I-1), (I-2), ( The group consisting of I'-1) and the diamines represented by (I'-2).

[3] The composition according to [1] or [2] wherein the tetracarboxylic dianhydrides A2 and B2 are each independently and contain an aromatic tetracarboxylic dianhydride represented by the following formulas 1 to 13, One or more of the group consisting of the aliphatic tetracarboxylic dianhydride represented by the above formulas 14 to 39 or the alicyclic tetracarboxylic dianhydride.

[4] The composition according to any one of [1] to [3] wherein the above tetracarboxylic dianhydride A2 contains pyromellitic dianhydride (PMDA) and/or cyclobutanetetracarboxylic acid anhydride.

[5] The composition according to any one of [1] to [4] wherein the diamine having the above-described side chain structure is a diamine represented by the following general formulas (III) to (VII).

[In the formula (III), R ¹ is a single bond, -O-, -COO-, -OCO, -CO-, -CONH- or -(CH ₂ ) _m -, wherein m is an integer from 1 to 6; R ² is a group having a steroid skeleton represented by the following formula (VIII), or an alkyl group bonded to the two amine groups of the benzene ring in a para position of 1 to 20 carbon atoms, or bonded to a benzene ring The positional relationship between the two amine groups is an alkyl group or a phenyl group having a carbon number of 1 to 10 in the meta position, wherein in the alkyl group having 2 to 6 carbon atoms of the above alkyl group, any -CH ₂ - may also be -O -, -CH=CH- or -C≡C-substituted, and the hydrogen atom bonded to the carbon atom forming the above benzene ring may also be combined with -F, -CH ₃ , -OCH ₃ , -OCH ₂ F, -OCHF ₂ or -OCF ₃ to replace]

[In the formula (VIII), R ^{1 0} , R ^{1 1} and R ^{1 2} are each independently a single bond, -O-, -COO-, -OCO-, -CONH- or an alkylene group having 1 to 3 carbon atoms. R ^{1 3} and R ^{1 4} are each independently -H, -F or -CH ₃ ; ring C is 1,4-phenylene or 1,4-cyclohexylene; R ^{1 5} is -H, -F, An alkyl group having 1 to 20 carbon atoms, a fluorine-substituted alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, -OCH ₂ F, -OCHF ₂ or -OCF ₃ , and preferably a carbon number of 1 ~12 alkyl group, carbon number 1~12 fluorine substituted alkyl group and carbon number 1 to 12; a, b and c are respectively independent integers representing 0~4; d, e and f are independent representations 0~3 An integer, and when f is 2 or 3, most of the rings C may be the same base or different bases; g and h are independently represented by 1 or 2; d+e+f≧1]

[In the formulae (IV) to (V), R ^{3 is} independently -H or -CH ₃ , respectively; R ^{4 is} independently -H or an alkyl or alkenyl group having 1 to 20 carbon atoms; and R ^{5 is} independently a single bond; , -C(=O)- or -CH ₂ -; R ⁶ and R ⁷ are each independently -H, an alkyl group having 1 to 20 carbon atoms or a phenyl group]

[In the formulae (VI) to (VII), R ^{8 is} independently -H or an alkyl group having 1 to 20 carbon atoms, and any -CH ₂ - of the alkyl group having 2 to 20 carbon atoms in the alkyl group may also be - O-, -CH=CH- or -C≡C-substituted; R ^{9 is} independently -O- or an alkylene group having 1 to 6 carbon atoms.

[6] A polyaminic acid or a derivative thereof, which comprises a diamine containing a diamine represented by the above general formula (I) or (I'), and a pyromellitic dianhydride and a cyclobutane IV The formic acid dianhydride is obtained by reacting tetracarboxylic acid dianhydride.

[7] A liquid crystal alignment agent, which comprises the composition according to any one of [1] to [5], or the polylysine or derivative thereof according to [6], and a solvent.

[8] A liquid crystal display device comprising: 1) a pair of substrates, an electrode disposed opposite to each other, or an electrode disposed opposite to each other, and 2) a liquid crystal alignment film formed on the pair of substrates The liquid crystal layer is sandwiched between the pair of substrates, wherein the liquid crystal alignment film is formed by applying the liquid crystal alignment agent according to [7] to the substrate and heating. It.

According to the present invention, it is possible to provide a liquid crystal alignment agent which can impart the afterimage characteristics required for a liquid crystal display element, a polyamine acid having a function of the liquid crystal alignment agent and a derivative thereof, and a composition thereof. Further, according to the present invention, it is possible to provide a liquid crystal display element of various driving methods capable of suppressing residual charges and improving afterimage characteristics.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

The composition of the present invention contains two or more kinds of polyamic acid or a derivative thereof.

At least one of the polylysine or a derivative thereof contained in the composition of the present invention is a diamine A1 and a tetracarboxylic acid which contain a diamine represented by the above general formula (I) or (I'). A polyaminic acid or a derivative thereof (hereinafter also referred to as "polyglycine A") obtained by reacting tetracarboxylic acid dianhydride A2.

Further, at least one other is a polyaminic acid or a derivative thereof obtained by reacting a diamine B1 having a diamine having a side chain structure with a tetracarboxylic dianhydride B2 (hereinafter, also referred to as "polyproline B" ).

Further, the composition of the present invention may contain only poly-proline A and B, and may further contain poly-proline or a derivative other than B.

<1. Polylysine A contained in the composition of the present invention>

As described above, the polyamic acid A contained in the composition of the present invention is a polyamine or a derivative thereof obtained by reacting at least a diamine A1 with a tetracarboxylic dianhydride A2.

The diamine A1 contains one or two or more kinds of diamines, and a part of the diamine contained in A1 may also be substituted with a monoamine.

The tetracarboxylic dianhydride A2 contains one or two or more tetracarboxylic dianhydrides, and a part of the tetracarboxylic dianhydride contained in A2 may also be substituted with a dicarboxylic acid.

Here, the derivative of the poly-proline comprises: 1) a polyimine of the polyamine and the carboxylic acid undergoing a dehydration ring-closing reaction; 2) a partial polyimine which undergoes a partial dehydration ring-closing reaction; 3) partially substituting one of the acid dianhydride contained in the tetracarboxylic dianhydride A2 into an organic dicarboxylic acid, and reacting the obtained polyacetamide-polyamide copolymer, and further 4) making the poly-proline- A polyamidoquinone imine which partially or completely undergoes a dehydration ring-closing reaction of one of the polyamidamide copolymers.

As described above, the diamine A1 contains one or two or more kinds of diamines and contains at least the diamine represented by the above general formula (I) or (I'). The two "-(CH ₂ ) _n NH ₂ " in the above general formula (I) are bonded to different ring carbons of the cyclohexane ring, respectively. Preferably, two "-(CH ₂ ) _n NH ₂ " are bonded to the 1st and 3rd positions, or the 1st and 4th positions of the cyclohexane ring, respectively, more preferably to the 1st and 3rd positions. Carbon. Further, _{n of the} two "-(CH ₂ ) _n NH ₂ " is an integer of 1 or 2, and may be the same or different.

As the diamine represented by the general formula (I), the following diamines can be mentioned. Among these, a diamine represented by the formula (I-1) or (I-2) is more preferred, and a diamine represented by the formula (I-2) is preferred.

In the above, two "-(CH ₂ ) _n NH ₂ " in the general formula (I') are bonded to different ring carbons of the benzene ring, respectively. Preferably, two "-(CH ₂ ) _n NH ₂ " are bonded to the carbon of the 1-position and 3-position, or the 1-position and 4-position of the benzene ring, respectively. More preferably, the carbon is bonded to the 1st and 3rd positions. Further, _{n of the} two "-(CH ₂ ) _n NH ₂ " is an integer of 1 or 2, and may be the same or different. Further, hydrogen bonded to a benzene ring carbon to which "-(CH ₂ ) _n NH ₂ " is not bonded may be substituted with a methyl group.

The diamine represented by the general formula (I') contained in the diamine A1 may, for example, be a diamine represented by the following formulas (I'-1) to (I'-4). In the diamine represented by the formula (I'-1) to (I'-4), any one of the hydrogens bonded to the hydrogen of the benzene ring may be substituted with 1 to 4 methyl groups.

Among these, a diamine represented by the formula (I'-1) or (I'-2) is more preferable, and a diamine represented by the formula (I'-2) is preferable.

In the above, the diamine A1 may contain the diamine represented by the general formula (I) or (I') alone or in combination of two or more. When two or more cases are contained, it is preferred to combine a diamine represented by the general formula (I) with a diamine represented by the general formula (I'), and more preferably a combination containing the formula (I-2). The diamine is a diamine of the formula (I'-2).

In the above diamine A1, the total content of the diamine represented by the general formula (I) and/or (I') is preferably from 10 to 100 mol% (mol%) of the total diamine, and more preferably 25~100 mol%.

The diamine other than the diamine represented by the general formula (I) or (I') contained in the diamine A1 may be any of them, and a diamine disclosed in Table 1 is preferred. Among the diamines disclosed in Table 1, preferred are Formulas 1-8, 1-9, 1-10, 1-1-1, 1-12, 1-13, 1-16, 1-19, 1- 34, 1-39, 1-40 diamine.

The diamine other than the diamine represented by the general formula (I) or (I') contained in the above diamine A1 may also be a nonanethanane having a decane bond other than the diamine disclosed in Table 1. Is a diamine. The decane-based diamine is not particularly limited, and those represented by the following formula (IX) can be preferably used in the present invention.

(Wherein, R ^{1 6} and R ^{1 7} is independently, carbon atoms and an alkyl group of 1 to 3, or a phenyl group, R ^{1 8} is methylene, phenylene or substituted phenylene .q represents alkyl of 1 To an integer of 6, r represents an integer from 1 to 10.)

Further, the diamine other than the diamine represented by the general formula (I) or (I') contained in the above diamine A1 is not limited to the diamine disclosed in Table 1 and the second one represented by the formula (IX). Amines, and other various forms of diamines are also present within the scope of achieving the objects of the present invention. Further, other diamines may be used singly or in combination of two or more.

As described above, a part of the diamine contained in the above diamine A1 may be substituted with a monoamine. By substituting a part of the diamine from the monoamine, the polymerization reaction is terminated, and further reaction can be suppressed, so that the molecular weight of the obtained polymer (polyglycine A) can be easily controlled. The ratio of the monoamine of the diamine is preferably controlled within a range not impairing the effects of the present invention, and is preferably set to be 10 mol% or less based on the amount of the total amine.

As described above, polyglycolic acid A was synthesized using tetracarboxylic acid dianhydride A2 as a raw material. The tetracarboxylic dianhydride A2 contains one or two or more tetracarboxylic dianhydrides. The tetracarboxylic dianhydride is represented by the following general formula (II).

(wherein A represents a tetravalent organic group).

Here, the tetracarboxylic dianhydride contained in the tetracarboxylic dianhydride A2 may be arbitrarily selected, and may be 1) aromatic tetracarboxylic dianhydride, 2) any of aliphatic tetracarboxylic dianhydride or alicyclic tetracarboxylic dianhydride. .

Further, since polylysine A is used as a component of the liquid crystal alignment agent, it is preferred to obtain a form which is soluble in a solvent. In order to form the polyamic acid A into a soluble form, it is preferred to appropriately select the tetracarboxylic dianhydride contained in the tetracarboxylic dianhydride A2.

Here, as for the specific example, the dianhydride represented by the following formula (II-1) to (II-13) is mentioned as a specific example. Among the following aromatic tetracarboxylic dianhydrides, dianhydrides represented by (II-1), (II-2), (II-5), (II-6) and (II-7) are more preferable. The best is pyromellitic dianhydride represented by (II-1).

The 2) aliphatic tetracarboxylic dianhydride or the alicyclic tetracarboxylic dianhydride contained in the tetracarboxylic acid dianhydride A2 is specifically exemplified by the acid dianhydrides represented by the following formulas (II-14) to (II39).

More preferably, the following acid dianhydrides are exemplified by the formulae (II-14) to (II-16), the formula (II-18), the formula (II-20), and the formulae (II-27) to (II- 29) The acid dianhydride shown is more preferably 1,2,3,4-cyclobutanetetracarboxylic dianhydride represented by the formula (II-14). Further, in order to prepare the polyamic acid A into a solvent-soluble polyimine, it is preferred to use the acid dianhydride represented by the formula (II-18) and the formulas (II-27) to (II-29). .

The tetracarboxylic dianhydride A2 may contain tetracarboxylic dianhydride alone or in combination of two or more. Preferably, the combination contains the above 1) aromatic tetracarboxylic dianhydride and 2) an aliphatic tetracarboxylic dianhydride or an alicyclic tetracarboxylic dianhydride, and more preferably a combination containing the pyromellitic acid represented by the formula (II-1). A dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride represented by formula (II-14).

In this embodiment, it contains aromatic tetracarboxylic dianhydride and aliphatic tetracarboxylic dianhydride or alicyclic tetracarboxylic dianhydride (especially good is pyromellitic dianhydride and 1,2,3,4-cyclobutane). A tetracarboxylic acid dianhydride of alkanetetracarboxylic acid dianhydride to synthesize polyamic acid, and a liquid crystal alignment film formed using the liquid crystal alignment agent containing the polyamic acid can impart a significant DC reduction to the liquid crystal display element containing the same. effect.

When the tetracarboxylic dianhydride A2 contains pyromellitic dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, pyromellitic dianhydride/1,2,3,4- is preferred. The molar ratio of cyclobutane tetracarboxylic dianhydride is from 10/90 to 90/10, more preferably from 15/85 to 75/25.

The polyamic acid A may have any weight average molecular weight, and is not particularly limited. However, when it is used as a component of the liquid crystal alignment agent, it is preferably 5 × 10 ³ or more, and more preferably 1 ×10 ⁴ . The polyamic acid A having a weight average molecular weight of 5 × 10 ³ or more does not evaporate in the step of firing the alignment film, and has desired physical properties as a component of the liquid crystal alignment agent.

The upper limit of the weight average molecular weight is preferably a viscosity of the liquid crystal alignment agent when it is used as a liquid crystal alignment agent, and the weight average molecular weight of the gelation of the liquid crystal alignment agent can be suppressed. 10 ⁵ or less.

Here, the weight average molecular weight of polyamic acid A can be measured by a gel permeation chromatography (GPC) method. For example, the polylysine A obtained by diluting dimethylformamide (DMF) is adjusted to a polyglycine concentration of about 1 weight percent (wt%), and an integrator C-R7A is used ( The product manufactured by Shimadzu Corporation was measured by gel permeation chromatography using DMF as a developing solvent, and was obtained by polystyrene conversion.

Further, the molecular weight distribution of polyamic acid A is represented by a degree of polymerization, and the degree of polymerization is a value of a weight average molecular weight / number average molecular weight (Mw / Mn), preferably 1.5 to 5. Here, the molecular weight distribution was measured by the GPC method which is the same as the molecular weight measurement.

Polylysine A can be produced using conventional methods. For example, in a reaction vessel having a raw material inlet, a nitrogen inlet, a thermometer, a stirrer, and a condenser, a desired amount of a diamine represented by the above general formula (I) or (I') is added. One or two or more kinds, and, depending on the case, one or more diamines of the above other diamines (Table 1 or Formula (17)), and further, a monoamine which is necessary.

Next, a solvent (for example, an N-methyl-2-pyrrolidone or an dimethylformamide of an amine-based polar solvent) and one or more of the tetracarboxylic dianhydrides represented by the above general formula (II) are added, and further Essential dicarboxylic acid. In this case, it is preferred to set the total amount of the tetracarboxylic dianhydride to be substantially equal to the total number of moles of the diamine (the molar ratio is about 0.9 to 1.1).

Stirring is continued, and the reaction is carried out at a temperature of 0 to 70 ° C for 1 to 48 hours to obtain a polyaminic acid solution. Further, by heating to increase the reaction temperature (for example, 50 to 80 ° C), a polyglycine having a small molecular weight can be obtained.

The precipitate was precipitated with a large amount of a poor solvent, and the solid component was completely separated from the solvent by filtration or the like, and analyzed by IR or NMR, whereby polyglycolic acid A was identified. Further, the solid polyaminic acid A is decomposed with a strongly basic aqueous solution such as KOH or NaOH, and extracted with an organic solvent, and further analyzed by GC, HPLC or GC-MS, whereby the monomer used can be identified. .

The resulting polyamic acid solution is adjusted to the desired viscosity and may be diluted with a solvent.

Further, when polylysine A is made into a poly-proline derivative, that is, a soluble polyimine, the obtained polyaminic acid solution can be used as a dehydrating agent, anhydrous acetic acid, anhydrous propionic acid, and anhydrous three. An acid anhydride such as fluoroacetic acid or a tertiary amine such as triethylamine, pyridine or trimethylpyridine which is a dehydration ring-closing catalyst is obtained by a ruthenium imidization reaction at a temperature of 20 to 150 °C.

Alternatively, a polyglycine may be precipitated from a polyglycolic acid solution obtained by using a large amount of a poor solvent (an alcohol solvent such as methanol, ethanol or isopropyl alcohol or a glycol solvent), and the precipitated product may be precipitated. The polyaminic acid is subjected to a hydrazine imidization reaction at a temperature of 20 to 150 ° C in a solvent such as toluene or xylene, together with the same dehydrating agent and a dehydration ring-closing catalyst.

In the above hydrazine imidization reaction, the ratio of the dehydrating agent to the dehydration ring-closing catalyst is preferably 0.1 to 10 (mole ratio). It is preferable that the total amount of the two is 1.5 to 10 moles per mole of the amount of the acid dianhydride contained in the tetracarboxylic dianhydride A2 to be used. By adjusting the chemical hydrazide dehydrating agent, the amount of the catalyst, the reaction temperature, and the reaction time, the degree of hydrazine imidation can be controlled, and a partial polyimine can be obtained.

The obtained polyimine may be used as a liquid crystal alignment agent, or may be used as a liquid crystal alignment agent, or may be used as a liquid crystal alignment agent without being dissolved in a solvent to be described later.

Further, as described above, a part of the acid dianhydride contained in the tetracarboxylic dianhydride A2 may be substituted with an organic dicarboxylic acid. When polyphosphoric acid A is produced using A2 containing an organic dicarboxylic acid, a poly-proline-polyamine copolymer can be obtained. Here, the ratio of the dicarboxylic acid of the tetracarboxylic dianhydride is preferably controlled within a range that does not impair the effects of the present invention, and is preferably 10 mol% or less in a suitable amount.

Further, polyamidoquinone imine can be produced by chemically imidating the polyamido-polyamide copolymer.

Polylysine A can be used as a component of a liquid crystal alignment agent by mixing with polyglycolic acid B described later. Further, as described below, polyglycolic acid A alone may be used as a component of the liquid crystal alignment agent.

<2. Polylysine B contained in the composition of the present invention>

As described above, the polyglycolic acid B contained in the composition of the present invention is a polyglycine or a derivative thereof obtained by reacting a diamine B1 with a tetracarboxylic dianhydride B2.

The diamine B1 contains one or two or more kinds of diamines, and one part of the diamine contained in B1 may be substituted with a monoamine.

The tetracarboxylic dianhydride B2 contains one or two or more kinds of tetracarboxylic dianhydride, and one part of the tetracarboxylic dianhydride contained in B2 may be substituted with a dicarboxylic acid.

The poly-proline derivative comprises: 1) a polyimine which undergoes a dehydration ring-closing reaction of all the amine groups of poly-proline and a carboxylic acid; 2) a partial polyimine which has a partial dehydration ring-closing reaction; 3) use a poly-proline-polyamine copolymer obtained by partially substituting one of tetracarboxylic dianhydrides with B2 of an organic dicarboxylic acid; and further 4) partially or wholly-treating one of the poly-proline-polyamine copolymers A polyamine amidoxime which dehydrates the ring closure reaction.

As described above, the diamine B1 contains one or two or more kinds of diamines and at least contains a diamine having a side chain structure. Further, if necessary, it may further contain any other diamine. Here, as the other diamine, a diamine as disclosed in the above Table 1, a diamine represented by the above formula (IX), or a diamine represented by the above general formula (I) or (I') may be mentioned. . The molar ratio of the "diamine/other diamine having a side chain structure" in the diamine B1 can be adjusted according to the structure of the selected diamine having a side chain structure and the desired pretilt angle. Preferably, it is from 100/0 to 1/99, more preferably from 80/20 to 5/95.

Further, a part of the diamine contained in the diamine B1 may be substituted with a monoamine. Here, it is preferred to set the ratio of the monoamine to the diamine to 10 mol% or less.

The diamine having a side chain structure means a diamine having a side chain when a chain linking two amine groups is used as a main chain. That is, a diamine having a side chain structure, by reacting with a tetracarboxylic acid dianhydride, can provide a polyaminic acid or a polyimine (a branched polyamine or a polyamine) having a side chain group with respect to a polymer main chain. Branched polyimine).

It is known that a liquid crystal alignment film formed of a liquid crystal alignment agent containing a polyamic acid or a polyimine having a side chain group with respect to a polymer main chain can increase the pretilt angle in the liquid crystal display element. This case is disclosed, for example, in the above-mentioned patent document, Japanese Patent Laid-Open No. Hei 11-193345.

Therefore, the side chain of the diamine having a side chain structure can be appropriately selected according to the required pretilt angle. For example, a side chain is a group having 3 or more carbon atoms. Specific examples thereof include 1) a phenyl group, or an alkyl group, an alkenyl group or an alkynyl group having 3 or more carbon atoms; 2) a phenoxy group; an alkoxy group having 3 or more carbon atoms; an alkenyloxy group or an alkynyloxy group; 3) benzene a carbonyl group, or an alkylcarbonyl group having at least 3 carbon atoms, an alkenylcarbonyl group or an alkynylcarbonyl group; 4) a phenylcarbonyloxy group; or an alkylcarbonyloxy group having at least 3 carbon atoms, an alkenylcarbonyloxy group or an alkynylcarbonyl group; Oxyl; 5) phenoxycarbonyl, or alkoxycarbonyl having 3 or more carbon atoms, alkenyloxycarbonyl or alkynyloxycarbonyl; 6) phenylaminocarbonyl, or alkylaminocarbonyl having 3 or more carbon atoms And alkenylaminocarbonyl or alkynylaminocarbonyl; and 7) a cyclic alkyl group having 3 or more carbon atoms, but is not limited thereto.

Specific examples of the diamine having a side chain structure include the diamines represented by the above general formulas (III) to (VII).

In the above general formula (III), two amine groups are bonded to the phenyl ring carbon, and it is preferred that the bonding positions of the two amine groups are partial or opposite. More preferably, when the bonding position of "R ² -R ¹ -" is set to 1 position, the two amine groups are bonded to the 3 position and the 5 position, or the 2 position and the 5 position, respectively.

As the diamine represented by the general formula (III), for example, a diamine represented by the formula (III-1) to (III-31) can be cited.

In the formulae (III-1) to (III-3), R ^{1 9 is} preferably an alkyl group having 4 to 12 carbon atoms, and in the formula (III-4), R ^{2 0 is} preferably a carbon number of 6 to 20 Alkyl group.

In the formula, R ^{2 2} is an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, and is preferably an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. R ^{2 3 is} preferably hydrogen, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms.

In the above general formula (IV), preferably one of the two "NH ₂ -Ph-R ⁵ -O-" groups is bonded to the 3 position of the steroid core, and the other side is bonded to the 6 or 7 position, preferably It is bonded to 6 digits. Further, it is preferred that the two amine groups are bonded to the phenyl ring carbon, respectively, and bonded to the opposite or opposite position with respect to the bonding position of R ⁵ .

As the diamine represented by the general formula (IV), for example, a diamine represented by the formulae (IV-1) to (IV-4) can be cited.

In the general formula (V), two "NH ₂ -(R ⁷ -)Ph-R ⁵ -O-" are bonded to the phenyl ring carbon, respectively, and preferably to the carbon to which the steroid core is bonded. Bonded to the opposite or opposite carbon. Further, the two amine groups are bonded to the phenyl ring carbon, respectively, and are preferably bonded to a position opposite to or opposite to R ⁵ .

As the diamine represented by the general formula (V), for example, a diamine represented by the formulae (V-1) to (V-8) can be cited.

In the above general formula (VI) or (VII), the two amine groups are bonded to the phenyl ring carbon, respectively, and are preferably bonded to a position opposite to or opposite to R ⁹ .

The diamine represented by the general formula (VI) may, for example, be a diamine represented by the formula (VI-1) to (VI-3), and the diamine represented by the general formula (VII) may be enumerated. For example, the diamine represented by (VII-1).

In the formula, R ^{2 1 is} preferably hydrogen or an alkyl group having 1 to 20 carbon atoms.

The polyamic acid B is combined (mixed) with the above polyamic acid A, whereby a preferable property as a component of the liquid crystal alignment agent can be imparted to the composition of the present invention.

Specifically, the pretilt angle can be adjusted for the liquid crystal alignment film formed using the composition of the present invention by appropriately selecting the type and combination of the diamine contained in the diamine B1 which is a raw material of the polyamic acid B.

In many cases, in the case of a TN type liquid crystal display element or an STN type liquid crystal display element, a pretilt angle of about 3 to 10 degrees is required, and in the case of an OCB type liquid crystal display element, a pretilt angle of about 7 to 20 degrees is required. In the case of a VA type liquid crystal display element, a pretilt angle of about 80 to 90 degrees is required. Therefore, the liquid crystal alignment agent containing the composition of the present invention can be appropriately adjusted in the pretilt angle, and can be applied to any type of liquid crystal display element.

Further, a liquid crystal alignment agent which uses poly-Proline A in combination with poly-proline B is used alone, and is suitable for forming an alignment film of an IPS-type liquid crystal display element (pretilt angle of 0°), which will be described later. .

Hereinafter, the diamine (diamine having a side chain structure) contained in the diamine B2 will be described in relation to the driving method (pretilt angle) of the liquid crystal display element.

1) When a TN type liquid crystal display element or an OCB type liquid crystal display element is used in the case of forming an alignment film in the above display element, it is preferable to contain the above general formulas (VI-1) to (VI-3), or The diamine B1 of the diamine represented by the general formula (VII-1) is obtained as a polyphthalic acid B, and the composition of the present invention containing polyglycolic acid B is used as a liquid crystal alignment agent component.

2) In the case of forming an alignment film in a VA type liquid crystal display device, it is preferable to contain a diamine represented by the above general formula (III-11) to (III-25) ( Further preferably, polyamine amide B is obtained by diamine B1 of the general formula (III-19) to (III-25), and the composition of the present invention containing polyglycolic acid B is obtained. It is used as a liquid crystal alignment agent component.

The polyamic acid B can be obtained by reacting the above diamine B1 with the tetracarboxylic dianhydride B2, and the tetracarboxylic dianhydride contained in the tetracarboxylic dianhydride B2 can be exemplified in the description of the tetracarboxylic dianhydride A2. The disclosed tetracarboxylic dianhydride is the same.

Further, similarly to A2, a part of the tetracarboxylic dianhydride contained in the tetracarboxylic dianhydride B2 may be substituted with a dicarboxylic acid.

The polyamic acid B is the same as the polyamic acid A, and may have any weight average molecular weight, and is not particularly limited, and is preferably 5 × 10 ³ when used as a component of the liquid crystal alignment agent. The above, and more preferably, is 1 × 10 ⁴ . The polyamic acid B having a weight average molecular weight of 5 × 10 ³ or more does not evaporate in the step of firing the alignment film, and has better physical properties as a component of the liquid crystal alignment agent.

The upper limit of the weight average molecular weight may be a weight average molecular weight which is preferably used as a liquid crystal alignment agent and which suppresses gelation of the liquid crystal alignment agent. For a suitable amount, it is preferably 5 × 10 ⁵ or less.

Further, the molecular weight distribution of polyamic acid B can be represented by a polymerization degree distribution, and the polymerization degree distribution means a value of a weight average molecular weight / number average molecular weight (Mw / Mn), and preferably this value is 1.5 to 5.

The weight average molecular weight and molecular weight distribution of polyglycolic acid B were measured in the same manner as in the case of polyglycolic acid A.

Polylysine B can be produced in the same manner as polylysine A. In addition, for the production method of the poly-proline B, for example, Japanese Patent Laid-Open No. Hei 01-25126, Japanese Patent Laid-Open No. Hei 03-219213, Japanese Patent Laid-Open No. Hei 06-228061, and Japanese Patent Laid-Open No. Hei 06- Japanese Patent Publication No. 265911 and Japanese Patent Laid-Open No. 2002-162630.

<3. Composition of the present invention>

The composition of the present invention can be produced by mixing the above polyamic acid A with polyglycolic acid B. Preferably, the weight ratio of the polyamic acid A to the polyamic acid B to be mixed is A/B = 99/1 to 50/50, more preferably A/B = 95/5 to 80/20. This weight ratio can be appropriately adjusted according to the required pretilt angle, and if the ratio of polyamic acid B is increased, the pretilt angle can be increased.

<4. Polylysine or derivative thereof of the present invention>

As described above, polylysine A is combined with polyglycolic acid B, whereby it can be used as a component of a better liquid crystal hydrating agent. However, in order to use polylysine A as a component of the liquid crystal alignment agent, it is not necessarily required to be combined with polyglycolic acid B.

That is, poly-proline A can be used alone (not in combination with poly-proline B) as a component of a liquid crystal alignment agent. Since the liquid crystal alignment film formed of the liquid crystal alignment agent containing poly-Proline A alone can set the pretilt angle of the liquid crystal display element to 0 to 2°, it is particularly useful for the production of an IPS liquid crystal display element.

When the polyamic acid A and the polyaminic acid B are not used in combination as a component of the liquid crystal alignment agent, it is preferred to use the acid dianhydride as a raw material and the above aromatic tetracarboxylic dianhydride. A combination of the above aliphatic tetracarboxylic dianhydride or an alicyclic tetracarboxylic dianhydride. Particularly preferably, pyromellitic dianhydride represented by formula (II-1) and 1,2,3,4-cyclobutane tetracarboxylic dianhydride represented by formula (II-14) are produced. combination.

<5. Liquid crystal alignment agent of the present invention>

The liquid crystal alignment agent of the present invention contains the polyamic acid A, the composition of the polyamic acid A and the polyaminic acid B, and a solvent, and may further contain various additives contained in a usual liquid crystal alignment agent.

The content of the polyamic acid in the liquid crystal alignment agent of the present invention can be appropriately selected depending on the method of applying the substrate to the liquid crystal alignment agent. For example, it is preferably used in a liquid crystal alignment agent used in a printing machine (including a lithographic printing or ink jet printing machine, hereinafter referred to as a "printing machine") in a manufacturing process of a normal liquid crystal display element. The content of the proline is 0.5 to 30% by weight, more preferably 1 to 15% by weight, and can be appropriately adjusted depending on the relationship with the viscosity of the liquid crystal alignment agent (described later).

The solvent includes a solvent which is usually used in a production step or a use of a polymer component such as polyacrylamide, a soluble polyimine, or a polyamidimide, and can be appropriately selected depending on the purpose of use. Preferably, the solvent is a mixed solvent containing the following solvents: 1) an aprotic polar organic solvent which is a solvophilic solvent with respect to polyglycolic acid or soluble polyimine; 2) to change surface tension and improve coating properties, etc. A solvent for the purpose.

If a solvent is exemplified, it is as follows.

1) an aprotic polar organic solvent (hereinafter, an aprotic polar organic solvent) which is a solvophilic solvent with respect to polyamic acid or a soluble polyimine, for example: N-methyl-2-pyrrolidone, dimethyl Imidazolinone, N-methyl caprolactam, N-methylpropionamide, N,N-dimethylacetamide, dimethyl hydrazine, N,N-dimethylformamide, N , N-dimethylformamide, diethylacetamide, γ-butyrolactone, γ-valerolactone. More preferably, N-methyl-2-pyrrolidone, dimethylimidazolidinone, γ-butyrolactone, γ-valerolactone or the like is exemplified.

2) A solvent (hereinafter, other solvent) for the purpose of changing the surface tension and improving the coating property, etc. is, for example, an alkyl lactate, 3-methyl-3-methoxybutanol, tetralin, isophorone, Ethylene glycol monoalkyl ether such as ethylene glycol monobutyl ether, diethylene glycol monoalkyl ether such as diethylene glycol monoethyl ether, ethylene glycol monoalkyl ether or phenyl acetate, triethylene glycol monoalkyl ether, propylene glycol single An ester compound such as dipropylene glycol monoalkyl ether such as propylene glycol monoalkyl ether or diethyl malonate or dipropylene glycol monoalkyl ether such as dipropylene glycol monomethyl ether or the like. Among the above, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and the like are more preferably exemplified.

The type and ratio of the aprotic polar solvent and other solvents can be appropriately set in consideration of the printability, coatability, solubility, and storage stability of the liquid crystal alignment agent. The aprotic polar solvent tends to be relatively superior in solubility and storage stability compared to other solvents, while other solvents tend to have excellent printability and coatability.

As described above, the liquid crystal alignment agent of the present invention may also contain various additives. As the various additives, a polymer compound other than polyamine or a derivative thereof, or a low molecular compound may be selected depending on the purpose.

For example, a soluble polymer compound can also be used as an additive, and by adding it to an organic solvent, the electrical characteristics or alignment of the formed alignment film can be controlled. Examples of the polymer compound include polydecylamine, polyurethane, polyurea, polyester, polyepoxide, polyester polyol, hydrazine-modified polyurethane, hydrazine-modified polyester, and the like. .

Further, as an example of the additive of the low molecular compound, 1) when it is desired to improve the coatability, a surfactant which achieves a related purpose can be used, and 2) when it is necessary to improve the charge prevention property, a charge preventive agent can be used, and When it is desired to improve the adhesion to the substrate or the rubbing resistance, a decane coupling agent or a titanium coupling agent can be used.

Examples of the above decane-based coupling agent include vinyltrimethoxydecane, vinyltriethoxydecane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxy. Decane, N-(2-aminoethyl)-3-aminopropylmethyltrimethoxydecane, p-aminophenyltrimethoxydecane, p-aminophenyltriethoxydecane, partial amino group Phenyltrimethoxydecane, partial aminophenyltriethoxydecane, 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 3-glycidoxypropyl Trimethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, 3-chloropropylmethyldi Methoxydecane, 3-chloropropyltrimethoxydecane, 3-methylpropenyloxypropyltrimethoxydecane, 3-mercaptopropyltrimethoxydecane, N-(1,3-dimethyl Butylene)-3-(triethoxydecane)-1-propylamine, N,N'-bis[3-(trimethoxydecyl)propyl]vinyldiamine, and the like.

The additive is added in an amount of from 0 to 10% by weight, and preferably from 0.1 to 3% by weight, based on the weight of the polyamic acid and its derivative.

The viscosity of the liquid crystal alignment agent of the present invention varies depending on the method of application, the concentration of the polyaminic acid and its derivative, the type of the polylysine and its derivative used, and the kind and ratio of the solvent. For example, it is 5 to 100 mPa when coated by a printing press. s (more preferably 10~80 mPa.s). If less than 5 mPa. s is difficult to get a full film thickness, if more than 100 mPa. s printing unevenness will become larger. 5 to 200 mPa when coated by spin coating. s (more preferably 10 to 100 mPa.s) is more suitable.

The viscosity of the liquid crystal alignment agent is measured by a rotational viscosity measurement method, for example, using a rotary viscometer (TVE-20L type manufactured by Toki Sangyo Co., Ltd.) (measurement temperature: 25 ° C).

<6. Liquid crystal display element of the present invention>

The liquid crystal display device of the present invention comprises: 1) a pair of substrates disposed opposite to each other; 2) a liquid crystal alignment film formed on a surface of the pair of substrates facing each other; and 3) a liquid crystal layer sandwiched between the pair of substrates. Here, the electrode may be disposed on both of the pair of substrates. However, in the case of an IPS type liquid crystal display device, an electrode (a comb-shaped or sawtooth electrode) is disposed on one of the pair of substrates.

The liquid crystal alignment film system is formed by applying the liquid crystal alignment agent of the present invention to the substrate and heating it. Here, it is preferred that the film thickness of the liquid crystal alignment film is 10 to 300 nm, and more preferably 30 to 100 nm. Further, it is preferred that the liquid crystal alignment film is subjected to a rubbing treatment.

Preferably, one of the opposite alignments is a transparent substrate (for example, a glass substrate) to which the substrate to which the electrode is attached.

The liquid crystal layer sandwiched between the pair of substrates contains a liquid crystal composition. Here, the liquid crystal composition is not particularly limited, and any composition of a liquid crystal composition having a positive dielectric anisotropy and a liquid crystal composition having a negative dielectric anisotropy may be used depending on the driving mode.

An example of a liquid crystal composition having a positive dielectric anisotropy is disclosed in Japanese Patent No. 3086228, Japanese Patent No. 2635435, Japanese Patent Laid-Open No. Hei 5-501735, and Japanese Patent Laid-Open No. Hei 8-157828 Japanese Patent Laid-Open No. Hei 8-231960, Japanese Patent Laid-Open No. Hei 9-241644 (EP 885 272 A1), Japanese Patent Laid-Open No. Hei 9-302346 (EP 806 466 A1), and Japanese Patent Laid-Open No. Hei 8-199168 (EP722998A1) Japanese Patent Laid-Open No. Hei 9-235552, Japanese Patent Laid-Open No. Hei 9-255956, Japanese Patent Laid-Open No. Hei 9-241643 (EP885271A1), Japanese Patent Laid-Open No. Hei 10-204016 (EP844229A1), Japanese Patent Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei.

The liquid crystal composition used in the VA liquid crystal display device can be various liquid crystal compositions having a negative dielectric anisotropy. Examples of the preferred liquid crystal composition are disclosed in Japanese Laid-Open Patent Publication No. SHO 57-114532, Japanese Patent Laid-Open No. Hei No. 2-4725, Japanese Patent Laid-Open No. Hei-4-224885, and Japanese Patent Laid-Open No. Hei 8-40953 Japanese Patent Laid-Open No. Hei 8-104869, Japanese Patent Laid-Open No. Hei 10-168076, Japanese Patent Application Laid-Open No. Hei No. Hei No. Hei 10- No. Japanese Patent Laid-Open No. Hei 10-236992, Japanese Patent Laid-Open No. Hei 10-236993, Japanese Patent Laid-Open No. Hei 10-236994, Japanese Patent Application Laid-Open No. Hei No. Hei 10--237000, Japanese Patent Laid-Open No. Hei 10-237004 Japanese Patent Laid-Open No. Hei 10-237024, Japanese Patent Laid-Open No. Hei 10-237035, Japanese Patent Laid-Open No. Hei 10-237075, Japanese Patent Laid-Open No. Hei 10-237076, and Japanese Patent Laid-Open No. Hei 10-237448 Japanese Patent Laid-Open No. Hei 10-287874, Japanese Patent Laid-Open No. Hei 10-287875, Japanese Patent Laid-Open No. Hei 10-291 Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. Japanese Patent Laid-Open Publication No. 2001-192657, and the like.

In the liquid crystal composition in which the above dielectric anisotropy is positive or negative, the addition of one or more optically active compounds does not have any influence.

The liquid crystal display element of the present invention may of course have other components.

For example, in a TFT liquid crystal element using a color display of a thin film transistor, a thin film transistor, an insulating film, a protective film, a signal electrode, a pixel electrode, and the like are formed on the first transparent substrate, and the second transparent substrate can be formed on the second transparent substrate. A black matrix, a color filter, a planarization film, a pixel electrode, and the like that block light other than the pixel region.

Further, in the VA liquid crystal display device, in particular, the MVA liquid crystal display device, microscopic projections called domains are formed on the first transparent substrate. Further, a spacer for adjusting the cell gap between the substrates may be formed.

The liquid crystal display device of the present invention can be produced by any method, for example, by the following steps: 1) a step of coating a liquid crystal alignment agent on the above two transparent substrates; 2) drying the coated liquid crystal alignment a step of the agent; 3) a step of performing a necessary heat treatment for dehydrating the dried liquid crystal alignment agent and performing a ring closure reaction; 4) a step of aligning the obtained alignment film; 5) after bonding the two substrates, a step of enclosing liquid crystal between the substrates; or a step of dropping the liquid crystal to a substrate and bonding it to another substrate.

As for the coating method in the step of applying the liquid crystal alignment agent, a spin coating method, a printing method, a dip plating method, a dropping method, an ink jet method, or the like is generally known. These methods are also applicable to the present invention.

Further, as for the drying step and the method of performing the heat treatment step necessary for the dehydration and the ring closure reaction, a method of heat treatment in an oven or an infrared oven, a method of heat treatment on a hot plate, and the like are generally known. These methods are also applicable to the present invention. The drying step is preferably carried out at a relatively low temperature (50 to 100 ° C) in the range in which the solvent can be evaporated. The heat treatment step is preferably carried out at a temperature of usually about 150 to 300 °C.

In the alignment process, rubbing treatment is performed in a TN type liquid crystal display element, an STN type liquid crystal display element, an IPS type liquid crystal display element, and an OCB type liquid crystal display element. On the other hand, in the VA liquid crystal display device, the rubbing treatment is usually not performed.

Then, an adhesive is applied to one of the substrates to bond them, and liquid crystal is injected into the vacuum. In the case of the dropping method, the liquid crystal is dropped onto the substrate before being bonded, and then the other is bonded to the substrate. The liquid crystal display element of the present invention is produced by hardening an adhesive used for bonding by heat or ultraviolet rays.

A polarizing plate (polarizing film), a wavelength plate, a light scattering film, a driving circuit, and the like may be mounted in the liquid crystal display element of the present invention.

Preferably, the liquid crystal alignment film used for the TN type liquid crystal display element and the STN type liquid crystal display element can impart a pretilt angle of 3 to 10°, and preferably the liquid crystal alignment film used for the IPS type liquid crystal display element can be given 0 to 2 Preferably, the liquid crystal alignment film used for the OCB type liquid crystal display element can impart a pretilt angle of 5 to 45 degrees, preferably 7 to 15 degrees, preferably a liquid crystal alignment for a VA type liquid crystal display element. The film can impart a pretilt angle of 85 to 90°. As described above, the adjustment of the pretilt angle is mainly by adjusting 1) the kind of the diamine which is the raw material of the polyamic acid B of the composition of the present invention, and the content ratio thereof, and 2) the polycondensation in the composition of the present invention. The content ratio of the amino acid A to the B is achieved.

Further, the liquid crystal display device of the present invention has a feature that the voltage holding ratio is high and the residual charge is low. The reason for this is that the liquid crystal alignment film of the liquid crystal display element of the present invention is formed by a liquid crystal alignment agent containing polyglycolic acid A. This case is also explained in the examples described later.

[Examples]

Hereinafter, the present invention will be described by way of examples and comparative examples, but the invention is not limited to these examples. In addition, the names of the tetracarboxylic dianhydride, the diamine, and the solvent used in the examples and the comparative examples are indicated by the following abbreviations.

[tetracarboxylic dianhydride] pyromellitic dianhydride {Formula (II-1)}: PMDA 1,2,3,4-cyclobutane tetracarboxylic dianhydride {Formula (II-14)}: CBDA butane IV Formic acid dianhydride {Formula (II-18)}: BTCA

[Diamine]m-phthaldimethyldiamine {Formula (I-2)}: MXDA 1,3-bis(aminomethyl)cyclohexane {Formula (I'-2)}: BAC 1,1 -Bis{4-[(4-aminophenyl)methyl]phenyl}-4-n-butylcyclohexane {Formula(VI-2)/R ^{2 1} =C ₄ H ₉ }: 4Ch 5 -{4-[2-(4-nheptylcyclohexyl)ethyl]cyclohexyl}phenylmethyl-1,3-diaminobenzene {Formula(III-25)/R ^{2 3} =C ₇ H _{1 5} }: 7Ch2Ch p-phenylenediamine (1-8 of Table 1): PDA 4,4'-diaminodiphenylmethane (1-11 of Table 1): DDM1,2-double (4- Aminophenyl)methane (1-16 of Table 1): DDEt

[Solvent] N-methyl-2-pyrrolidone: NMP γ-butyrolactone: GBL butyl cellosolve (ethylene glycol monobutyl ether): BC

<1. Synthesis of polyaminic acid> [Synthesis of polyamid A] Synthesis Example 1

1.9835 g (14.56 mmol) of MXDA and 35 g of dehydrated NMP were placed in a 100 ml four-necked flask equipped with a thermometer, a stirrer, a raw material inlet, and a nitrogen inlet, and stirred and dissolved under a dry nitrogen stream. Then, 1.5884 g (7.28 mmol) of PMDA and 1.4282 g (7.28 mmol) of CBDA were added, and allowed to react at room temperature for 30 hours. When the reaction temperature rises during the reaction, the reaction temperature is suppressed to about 70 ° C or lower to cause a reaction.

30 g of GBL and 30 g of BC were added to the obtained solution to synthesize a polyglycine solution (PA1) having a concentration of 5 wt%. The obtained PA1 has a viscosity of 20 mPa. s. Further, the produced polyamine had a weight average molecular weight of 44,000.

Synthesis Examples 2 to 7

A polyglycine solution (PA2 to PA7) was synthesized according to Synthesis Example 1, except that the composition of tetracarboxylic dianhydride, diamine, and solvent was changed to the ratio shown in Table 2. The results including Synthesis Example 1 are shown in Table 2.

[Synthesis of poly-proline B] Synthesis Examples 8 to 9

Polyamines (PA8 to PA9) having a side chain were synthesized according to Synthesis Example 1, except that the tetracarboxylic dianhydride, the diamine, and the solvent group were changed in the ratios shown in Table 3. The results are shown in Table 3.

[Synthesis of other polylysine] Comparative Synthesis Examples 1 to 2

A polyglycine solution (CPA 1 to 2) was synthesized according to Synthesis Example 1, except that the tetracarboxylic dianhydride, the diamine, and the solvent composition were changed in the ratios shown in Table 2. The results including Synthesis Example 1 are shown in Table 2.

<2. Production of liquid crystal display element> [Example 1]

A polyglycine solution (PA1) having a concentration of 5 wt% synthesized by Synthesis Example 1 was diluted to 3 wt% by a mixed solvent of NMP/BC = 1/1 (weight ratio) to prepare a liquid crystal alignment agent. . Using the obtained liquid crystal alignment agent, an IPS type liquid crystal display element was produced as follows.

IPS type liquid crystal display element manufacturing method

A two-glass substrate in which a glass substrate to which a comb-shaped electrode is attached and an electrodeless glass substrate for IPS shown in Fig. 1 is used. The liquid crystal alignment agent was applied onto a glass substrate to which the comb-shaped electrode was attached to the IPS and a glass substrate without an electrode by a spin coater to form a film having a film thickness of 100 nm. After coating, the film was dried by heating at 80 ° C for about 5 minutes, and then heat-treated at 220 ° C for 30 minutes to form a liquid crystal alignment film.

The two substrates on which the alignment film was formed were respectively used, and the friction processing apparatus manufactured by Iguchi GAUGE Co., Ltd. was used, and the amount of hair pressing on the rubbing cloth (hair length: 1.9 mm: human cotton) was 0.4 mm, and the gantry moving speed was set to At 60 mm/sec, the drum rotation speed was set to 1000 rpm, and the rubbing treatment was performed so as to be inclined by 30° with respect to the direction of the electrode.

The rubbed substrate was ultrasonically washed in ultrapure water for 5 minutes, and then the surface was washed with ethanol, followed by drying at 120 ° C for 30 minutes in an oven. A gap material of 4 μm was spread on the glass substrate to which the IPS attached the electrode with a comb shape. The surface on which the alignment film was formed was set to the inside, and the electrodeless glass substrate was placed in the opposite direction to the rubbing direction, and then sealed with an epoxy curing agent to prepare an antiparallel cell having a gap of 4 μm. The following liquid crystal composition A was injected into this unit, and the injection port was sealed with a light hardener. Then, heat treatment was performed at 110 ° C for 30 minutes to prepare an IPS type liquid crystal display element.

NI = 100.0 ° C, Δn = 0.093, Δ ε = 5.1.

[Examples 2 to 7]

A liquid crystal alignment agent was obtained in the same manner as in Example 1 except that PA2 to PA7 were used instead of PA1. Further, an IPS liquid crystal display device was produced in the same manner as in Example 1 using the obtained liquid crystal alignment agent.

[Comparative Examples 1 to 2]

A liquid crystal alignment agent was obtained in the same manner as in Example 1 except that CPA1 to CPA2 were used instead of PA1. Further, an IPS liquid crystal display device was produced in the same manner as in Example 1 using the obtained liquid crystal alignment agent.

[Embodiment 8]

The polyglycine solution (PA1) having a concentration of 5 wt% synthesized by Synthesis Example 1 and the polyamic acid solution (PA8) synthesized in Synthesis Example 8 were mixed at a weight ratio of 9/1. The obtained mixture was diluted to 4 wt% in a mixed solvent of NMP/BC = 1/1 (weight ratio) to prepare a liquid crystal alignment agent. Using the obtained liquid crystal alignment agent, a TN type liquid crystal display element was produced as described below.

Production of TN type liquid crystal display elements

The liquid crystal alignment agent was applied onto two glass substrates to which the ITO electrode was attached by a spin coater to form a film having a film thickness of 70 nm. After coating, the film was dried by heating at 80 ° C for about 5 minutes, and then heat-treated at 220 ° C for 30 minutes to prepare a liquid crystal alignment film.

The glass substrate on which one of the alignment films was formed was used, and the friction processing device manufactured by Iguchi GAUGE Co., Ltd. was used, and the amount of hair pressing on the rubbing cloth (hair length: 1.9 mm: human cotton) was 0.40 mm, and the gantry moving speed was set to Friction treatment was carried out at 60 mm/sec and the drum rotation speed was set to 1000 rpm. The rubbing direction was changed by 90° to the other glass substrate in such a manner as to be perpendicular to the rubbing direction of the other side. The substrate was ultrasonicated in ultrapure water for 5 minutes, and then the surface was washed with ethanol, followed by drying at 120 ° C for 30 minutes in an oven. Then, a gap material of 7 μm was spread on one of the glass substrates.

The surface on which the alignment film was formed was set to the inside, and the surface was placed in the rubbing direction so as to face each other, and then sealed with an epoxy curing agent to prepare a 90° torsion unit having a gap of 7 μm. In the unit, 5 parts by weight of the cholesterol phthalate as an optically active substance is added to 100 parts by weight of the liquid crystal composition A, and a homogeneous composition is injected, and the injection port is sealed with a light hardener. Then, heat treatment was performed at 110 ° C for 30 minutes to prepare a TN liquid crystal display element.

[Examples 9 to 14]

A liquid crystal alignment agent was obtained in the same manner as in Example 8 except that PA2 to PA7 were used instead of PA1. Further, a TN liquid crystal display device was produced in the same manner as in Example 8 using the obtained liquid crystal alignment agent.

[Comparative Example 3]

A liquid crystal alignment agent was obtained in the same manner as in Example 8 except that CPA1 was used instead of PA1. Further, a TN liquid crystal display device was produced in the same manner as in Example 8 using the obtained liquid crystal alignment agent.

[Example 15]

A polyglycine solution (PA1) having a concentration of 5 wt% synthesized by Synthesis Example 1 and a polyaminic acid solution (PA9) synthesized in Synthesis Example 9 were mixed at a weight ratio of 9/1. The obtained mixture was diluted to 4 wt% in a mixed solvent of NMP/BC = 1/1 (weight ratio) to prepare a liquid crystal alignment agent. Using this liquid crystal alignment agent, a VA liquid crystal display element was produced as follows.

VA type liquid crystal display element manufacturing method

The liquid crystal alignment agent was applied onto two glass substrates to which the ITO electrode was attached by a spin coater to form a film having a film thickness of 70 nm. After coating, the film was dried by heating at 80 ° C for about 5 minutes, and then heat-treated at 220 ° C for 30 minutes to form a liquid crystal alignment film.

A glass substrate on which an alignment film was formed was used, and a rubbing treatment apparatus manufactured by Iguchi GAUGE Co., Ltd. was used, and the amount of hair pressing on the rubbing cloth (hair length: 1.9 mm: human cotton) was 0.20 mm, and the gantry moving speed was set to 60 mm/ In the case of sec, the drum rotation speed is set to 1000 rpm, and rubbing treatment is performed. The glass substrate on which the alignment film was formed was ultrasonically washed in ultrapure water for 5 minutes, and then the surface was washed with ethanol, followed by drying at 120 ° C for 30 minutes in an oven.

A gap material of 4 μm was spread on one of the glass substrates, and the surface on which the alignment film was formed was set to the inside, and the rubbing direction was opposed to the opposite direction, and then sealed with an epoxy curing agent to form a gap of 4 μm. Anti-parallel unit. The following liquid crystal composition B was injected into this unit, and the injection port was sealed with a light hardener. Then, heat treatment was performed at 110 ° C for 30 minutes to prepare a VA liquid crystal display element.

NI = 75.4 ° C, Δn = 0.081, and Δ ε = -3.4.

[Examples 16 to 21]

A liquid crystal alignment agent was obtained in the same manner as in Example 15 except that PA2 to 7 were used instead of PA1. Further, a VA liquid crystal display device was produced in the same manner as in Example 15 except that the obtained liquid crystal alignment agent was used.

[Comparative Example 4]

A liquid crystal alignment agent was obtained in the same manner as in Example 15 except that CPA2 was used instead of PA1. Further, a VA liquid crystal display device was produced in the same manner as in Example 15 except that the obtained liquid crystal alignment agent was used.

<3. Evaluation of electrical characteristics> [Test Examples 1 to 7 and Comparative Test Examples 1 to 2]

The IPS type liquid crystal display elements produced in Examples 1 to 7 and Comparative Examples 1 to 2 were evaluated for electrical characteristics. Specifically, the measurement has 1) voltage holding ratio; 2) residual DC by the flicker free method; 3) residual DC by VT hysteresis; 4) residual DC by dielectric absorption method. Each measurement was carried out as follows. The results of these measurements are shown in Table 4.

1) Measurement of Voltage Retention Rate The liquid crystal physical property evaluation device 6254 type manufactured by TOYO Corporation was used to measure the voltage holding ratio. The measurement conditions were a gate width of 60 μs, a frequency of 0.3 Hz, and a wave height of ±5 V, and the measurement temperature was set to 60 °C. The larger the value, the better the electrical characteristics.

2) FG-110 manufactured by Yokogawa Electric Co., Ltd. on a rectangular wave of 30 Hz, 2 V (liquid crystal composition A) or 5.5 V (liquid crystal composition B) by measurement of residual DC by the flicker-free method. The DC voltage of 1 V (IPS type liquid crystal display element and VA type liquid crystal display element) or 3 V (TN type liquid crystal display element) was superimposed and applied for 30 minutes. The voltage was flashed off 30 minutes after the end of the application.

In the table, as the initial value, the flicker erase voltage after the end of application and the flicker erase voltage after 10 minutes are revealed. Further, the measurement temperature was set to 25 °C. The closer the value is to 0 (zero), the better the electrical characteristics.

3) The residual DC measured by the VT hysteresis method is applied to both sides of the liquid crystal display element, and the polarization axis of one of the polarizing plates is arranged to coincide with the rubbing direction, and the other polarizing plate is orthogonal thereto (straight polarized light) In the case of the 5100 AGS manufactured by Otsuka Electronics Co., Ltd., the transmittance (%T) of each voltage (V) of 0.1 to 10 V was measured with a rectangular wave of 1 kHz. Next, a voltage of a waveform of a DC voltage of 1 V was applied for 4 hours to a rectangular wave of 6 V as a load voltage, and thereafter, a rectangular wave of 1 kHz was again measured for transmission of each voltage (V) of 0.1 to 10 V. Rate (%T). Further, the measurement temperature was set to 60 °C.

The difference (ΔT) between the transmittances before and after the application of the load voltage was obtained. In Table 4, the value of the voltage (V10) at a transmittance of 10% and the ΔT at a voltage of 30% (V30) in the measurement before the application of the load voltage is disclosed. The smaller the ΔT, the better the electrical characteristics.

4) Measurement of Residual DC by Dielectric Absorption Method A liquid crystal physical property evaluation device 6254 manufactured by TOYO Corporation was used, and measurement of residual DC by a dielectric absorption method was carried out. The measurement conditions were such that a direct current of 5 V was applied to the cell for 1 hour, and short-circuited for 1 second, thereby observing the potential difference of 30 minutes. The largest residual DC and the smallest residual DC are revealed in the table. Further, the measurement temperature was 60 °C. The smaller the value, the better the electrical characteristics.

As shown in Table 4, the voltage holding ratio was 92% or more in either case. On the other hand, in the test examples 1 to 2 in which the liquid crystal alignment agent of the present invention was used, the residual DC was remarkably suppressed by any of the measurement methods as compared with the case of the comparative test examples 1 to 2.

That is, it was found that in Test Examples 1 to 7, in the non-flicker method, the residual DC of either the initial stage and the 30-minute period was low. In the VT hysteresis method, when either of 2V and 3V is used, the transmittance difference ΔT is small, so that the residual voltage can be suppressed. Further, in the dielectric attraction method, the maximum value and the minimum value of the residual DC are both low.

[Test Examples 8 to 14 and Comparative Test Example 3]

The evaluation of electrical characteristics was carried out on the TN type liquid crystal display elements produced in Examples 8 to 14 and Comparative Example 3. Specifically, in the same manner as in Test Example 1, 1) the voltage holding ratio; 2) the residual DC by the flicker-free method; and 3) the residual DC by the dielectric absorption method. The results of these measurements are shown in Table 5.

As shown in Table 5, the voltage holding ratio was 94% or more in either case. On the other hand, even in any of the measurement methods of the residual DC, in the test examples 8 to 14 using the liquid crystal alignment agent of the present invention, the residual DC was remarkably suppressed as compared with the case of the comparative test example 3.

[Test Examples 15 to 21 and Comparative Test Example 4]

The electric characteristics were evaluated by the VA liquid crystal display elements produced in Examples 15 to 21 and Comparative Example 4. Specifically, the measurement includes: 1) voltage holding ratio; 2) residual DC by the flicker-free method; and 3) residual DC by the VT hysteresis method.

The measurement of 1) and 2) was measured in the same manner as in Test Example 1. In the measurement of 3), a DC voltage of 7 V was applied for 4 hours except for a waveform voltage of an offset DC voltage of 4 V applied for 4 hours on a rectangular wave of 6 V, and was measured in the same manner as in Test Example 1. Load voltage.

The results of these measurements are shown in Table 6.

As shown in Table 6, the voltage holding ratio was 94% or more in either case. On the other hand, in any of Test Examples 15 to 21 in which the liquid crystal alignment agent of the present invention was used, the residual DC was remarkably suppressed as compared with the case of Comparative Test Example 4, even if the residual DC was used.

As described above, the liquid crystal alignment agent containing polyglycine and its derivative of the present invention can be used for the formation of a liquid crystal alignment film for liquid crystal display elements of various display driving methods. Then, in any of the liquid crystal display elements of the display driving method, the voltage holding ratio is high, and residual charges can be suppressed.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

Fig. 1 is a view showing two glass substrates of a glass substrate to which a comb-shaped electrode is attached and an electrodeless glass substrate.

Claims (12)

A composition comprising two or more polylysines or derivatives thereof, the composition comprising: A) polyglycine or a derivative thereof thereof, which comprises the following general formula (I) or (I' a diamine A1 of the indicated diamine is reacted with a tetracarboxylic dianhydride A2; and B) a polyaminic acid or a derivative thereof B, which is a diamine B1 and a tetra-containing diamine having a side chain structure. The formic acid dianhydride B2 is obtained by reaction. (where n represents an integer of 1 or 2). The composition according to claim 1, wherein the diamine represented by the above general formula (I) or (I') is selected from the following structural formulae (I-1), (I-2), ( a group consisting of diamines represented by I'-1) and (I'-2) . The composition according to claim 1, wherein the tetracarboxylic dianhydrides A2 and B2 are each independently and contain an aromatic tetracarboxylic dianhydride represented by the following formulas 1 to 13, and the following formula 14 One or more of the group consisting of aliphatic tetracarboxylic dianhydride or alicyclic tetracarboxylic dianhydride represented by ~39 The composition according to claim 2, wherein the tetracarboxylic dianhydrides A2 and B2 are each independently and contain an aromatic tetracarboxylic dianhydride represented by the following formulas 1 to 13, and the following formula 14 One or more of the group consisting of aliphatic tetracarboxylic dianhydride or alicyclic tetracarboxylic dianhydride represented by ~39 The composition according to claim 1, wherein the tetracarboxylic dianhydride A2 contains pyromellitic dianhydride and/or cyclobutane tetracarboxylic dianhydride. The composition according to claim 2, wherein the tetracarboxylic dianhydride A2 contains pyromellitic dianhydride and/or cyclobutane tetracarboxylic dianhydride. The composition according to claim 3, wherein the tetracarboxylic dianhydride A2 contains pyromellitic dianhydride and/or cyclobutane tetracarboxylic dianhydride. The composition according to claim 4, wherein the tetracarboxylic dianhydride A2 contains pyromellitic dianhydride and/or cyclobutane tetracarboxylic dianhydride. The composition according to any one of claims 1 to 8, wherein the diamine having a side chain structure is a diamine represented by the following general formulas (III) to (VII), [In the formula (III), R ¹ is a single bond, -O-, -COO-, -OCO, -CO-, -CONH- or -(CH2)m-, wherein m is an integer from 1 to 6; R ² a group having a steroid skeleton represented by the following formula (VIII), or an alkyl group bonded to the two amine groups of the benzene ring at a position of 1 to 20 carbon atoms, or bonded to a benzene ring The positional relationship of the two amine groups is an alkyl group or a phenyl group having a carbon number of 1 to 10 in the meta position, wherein in the alkyl group having 2 to 6 carbon atoms of the above alkyl group, any -CH ₂ - may also be -O- , -CH=CH- or -C≡C-substituted, and the hydrogen atom bonded to the carbon atom forming the above benzene ring may also be -F, -CH3, -OCH3, -OCH ₂ F, -OCHF ₂ or - OCF ₃ is replaced] [In the formula (VIII), R ^{1 0} , R ^{1 1} and R ^{1 2} are each independently a single bond, -O-, -COO-, -OCO-, -CONH- or a C 1 to 3 alkylene group. R ^{1 3} and R ^{1 4} are each independently -H, -F or -CH ₃ ; ring C is 1,4-phenylene or 1,4-cyclohexylene; R ^{1 5} is -H, -F, An alkyl group having 1 to 20 carbon atoms, a fluorine-substituted alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, -OCH ₂ F, -OCHF ₂ or -OCF ₃ ; a, b and c are each independently To represent an integer from 0 to 4; d, e and f are each independently an integer representing 0 to 3, and when f is 2 or 3, a plurality of rings C may be the same or different bases; h is independently 1 or 2; d+e+f≧1] [In the formulae (IV) to (V), R ^{3 is} independently -H or -CH ₃ , respectively; R ^{4 is} independently -H or an alkyl or alkenyl group having 1 to 20 carbon atoms; and R ^{5 is} independently a single bond; , -C(=O)- or -CH ₂ -; R ⁶ and R ⁷ are each independently -H, an alkyl group having 1 to 20 carbon atoms or a phenyl group] [In the formulae (VI) to (VII), R ^{8 is} independently -H or an alkyl group having 1 to 20 carbon atoms, and any -CH ₂ - of the alkyl group having 2 to 20 carbon atoms in the alkyl group may also be -O-, -CH=CH- or -C≡C-substituted; R ^{9 is} independently -O- or a C 1 to 6 alkyl group. A polyaminic acid or a derivative thereof, which comprises a diamine containing a diamine represented by the following general formula (I) or (I'), and a pyromellitic dianhydride and a cyclobutane tetracarboxylic dianhydride. By reacting tetracarboxylic acid dianhydride, (where n represents an integer of 1 or 2). A liquid crystal alignment agent comprising the composition according to any one of the first to ninth aspects of the patent application, or the polyamic acid or derivative thereof of claim 10, and a solvent. A liquid crystal display device comprising: 1) a pair of substrates, an electrode disposed opposite to each other, or an electrode disposed opposite to each other, and 2) a liquid crystal alignment film formed on each of the pair of substrates And a liquid crystal layer sandwiched between the pair of substrates, wherein the liquid crystal alignment film is coated on the substrate by heating and applying the liquid crystal alignment agent according to claim 11 And formed.