JP4595417B2 - Phenylenediamine, alignment film formed using the same, and liquid crystal display device including the alignment film - Google Patents

Description

  The present invention relates to a novel phenylenediamine compound, polyamic acid, polyimide, polyamide, or polyamideimide synthesized using the phenylenediamine as a raw material. Furthermore, the present invention relates to an alignment film formed using a varnish containing at least one selected from the polyamic acid, polyimide, polyamide and polyamideimide, and a liquid crystal display device having the alignment film.

Liquid crystal display elements have been changed from twisted nematic (TN) to super twisted nematic (Super Twisted Nematic) in response to demands for higher display quality and response speed, such as screen enlargement and colorization, contrast and color development. : STN), and the driving system has been developed from the passive matrix system to the active matrix system. At present, a TFT type display element in which a thin film transistor (TFT) is attached to each pixel is a typical liquid crystal display element.
Further, in recent years, improvements in driving methods of TFT display devices have progressed, and in order to further increase the viewing angle, for example, in-plane switching (IPS) method and vertical alignment (hereinafter referred to as VA). In addition, an optically compensated bend (OCB) method having a response speed capable of handling moving images has been developed.

  The alignment film is a film provided at the interface between the substrate and the liquid crystal in the liquid crystal display element, and 1) aligns liquid crystal molecules in a certain direction and 2) tilts the substrate plane (provides a pretilt angle). It plays two roles. The angle of inclination of the liquid crystal molecules with respect to the substrate plane is referred to as “pretilt angle”. This name will be used hereinafter in this specification. Since the alignment film needs to minimize the deterioration of the alignment of liquid crystal molecules over time, chemical deterioration, and thermal deterioration, the alignment film material has a high glass transition point (Tg), In addition, polyimides that are excellent in chemical resistance and heat resistance are mainly used.

The alignment film is usually formed by the following procedure.
1) A solution containing polyamic acid or soluble polyimide is applied to a glass substrate with an electrode by a spinner method or a printing method,
2) The substrate is heated to dehydrate the polyamic acid to form a polyimide, or a polyimide thin film is formed by evaporating the solvent of the soluble polyimide solution,
3) Further, an alignment treatment process such as rubbing is performed.

  The substrate having the alignment film formed on the surface in this way is bonded to each other so as to assemble the cell, and the inside of the cell (between the two substrates) is decompressed and then immersed in the liquid crystal to open the opening. Then, liquid crystal is injected into the cell to produce a liquid crystal display element. However, in this manufacturing method, it takes time to inject liquid crystal, which is a problem particularly when manufacturing a display device for a large screen. Accordingly, in order to improve productivity, “drop injection” has recently started to be performed, in which liquid crystal is directly dropped onto an alignment film on a substrate and then a substrate is bonded to produce a liquid crystal display element.

The alignment film exhibits the following effects in the liquid crystal display element, and the liquid crystal display element including the alignment film is required to have the following characteristics.
(1) Giving an appropriate pretilt angle to liquid crystal molecules. In addition, the change in the pretilt angle due to the difference in indentation strength when the alignment film is rubbed or the temperature when heated is small. (2) Even if the alignment treatment is performed, alignment defects are not generated in the liquid crystal display element.
(3) Give an appropriate voltage holding ratio (Voltage Holding Ratio: VHR) to the liquid crystal display element.
(4) A phenomenon called “burn-in” in which an arbitrary image is displayed on the liquid crystal display element for a long time and then changed to another image and the previous image remains as an afterimage is less likely to occur.
In particular, since TFT type display elements are required to have a high voltage holding ratio and hardly cause image sticking, the alignment film used for the display elements is a high-quality alignment film that meets such requirements. It is requested.

  In the vertical alignment (VA) method, it is necessary to align liquid crystal molecules perpendicular to the substrate when no voltage is applied. It is known that this can usually be achieved by introducing a large substituent into a diamine compound which is a raw material of a component (polymer, for example, polyimide) of an alignment film. A substituted phenylenediamine derivative is suitable as a diamine compound having such a purpose and having a large substituent introduced therein. The substituted phenylenediamine derivative is a compound represented by the following formula (6) (Patent Document 1). And a compound represented by the following formula (7) (see Patent Document 2) is known.

However, in order to design an alignment film that satisfies the above-mentioned required characteristics and to produce a liquid crystal display device having the above-described characteristics, various diamines that are raw materials for components of the alignment film, that is, phenylene having various substituents Further development of diamine derivatives is necessary.
WO 97/30107 pamphlet JP 2002-327058 A

An object of the present invention is to provide a liquid crystal display element having characteristics that a voltage holding ratio (VHR) is high and “burn-in” hardly occurs. It is also preferable to provide a vertical alignment (VA) liquid crystal display element that satisfies such characteristics.
Another object of the present invention is to provide an alignment film that can bring the above characteristics to the liquid crystal display element. For example, an alignment film that can be subjected to alignment treatment without causing alignment defects in the liquid crystal display element, Alternatively, it is possible to provide an alignment film that can give an appropriate pretilt angle to liquid crystal molecules and hardly change the pretilt angle even when it is rubbed or heated. It is also preferable to provide an alignment film capable of vertically aligning liquid crystal molecules. Furthermore, it is to provide an alignment film capable of reducing the density of movable ions in the liquid crystal (for example, trapping the ions) in the liquid crystal display element.
Furthermore, the object of the present invention is to provide a material (for example, varnish) for forming the alignment film, a polymer (for example, polyamic acid, polyimide, polyamide, or polyamideimide) contained in the material, and a compound (phenylene) that is a raw material of the polymer. Diamine).

As a result of diligent research and development, the present inventors have found that an alignment film formed using a varnish containing a specific polymer produced from a specific phenylenediamine as a raw material has a pretilt angle of several to 90 ° in a liquid crystal display device. It was found that the pretilt angle is not changed even when an alignment process (including rubbing) or a cleaning process is performed.
In addition, the liquid crystal display device including this alignment film has been found to have excellent alignment stability of liquid crystal molecules, high voltage holding ratio (VHR), and low image sticking, and has completed the present invention.

That is, this invention is comprised from the following.
[1] A phenylenediamine represented by the following general formula ( 1a ). In formula (1a), ^{R 1} is hydrogen or methyl, is a group in which the N-Cycle represented by the following general formula (2). In the general formula (2), R ² is hydrogen or a linear or branched alkyl having 1 to 20 carbon atoms, provided that any —CH ₂ — in the alkyl is —CF ₂ —, —O—, or -C (= O) - may be substituted with, but, -CH ₂ that is continuous - none of -O-, or -C (= O) - not be substituted with, a ¹ , A ² , and A ³ are each independently a single bond, 1,4-cyclohexylene, 1,4-phenylene, or 1,4-bicyclo [2,2,2] octanylene, provided that In the 1,4-phenylene, 1 to 2 hydrogens on the benzene ring may be substituted with methyl, methoxy, or fluorine, and B ¹ , B ² , and B ³ are each independently Bond, alkylene having 1 to 4 carbon atoms, -O-, -OC (= ) -, - C (= O ) O -, - NR 3 C (= O) -, or -C (= O) N (-R 3) - an A, except that in the alkylene, arbitrary -CH _2- is -CF
_2- , -O-, or -C (= O)-may be substituted , but any continuous -CH ₂ -is substituted with -O- or C (= O)-. And R ³ is hydrogen or alkyl having 1 to 10 carbons.

[2] The phenylenediamine according to [1], wherein in the general formula ( 1a ), the amino group (—NH ₂ ) is located at the 3,5-position with respect to the amide group.
[3] The phenylenediamine according to [1], wherein in the general formula ( 1a ), the amino group (—NH ₂ ) is located at the 2,5-position with respect to the amide group .

[ 4 ] In the general formula (2),
R ² is hydrogen or a linear or branched alkyl having 1 to 20 carbon atoms,
A ¹ , A ² , and A ³ are each independently a single bond, 1,4-cyclohexylene, 1,4-phenylene,
B ^{1, B 2,} and ^{B 3} are each independently a single bond, a straight-chain alkylene having 1 to 4 carbon atoms, phenylene diamine according to [1].
[ 5 ] In the general formula (2),
R ² is a linear or branched alkyl having 1 to 12 carbon atoms,
A ¹ , A ² and A ³ are each independently 1,4-cyclohexylene or a single bond, and at least one is a single bond,
B ¹ , B ² and B ³ are each independently ethylene or a single bond, and at least two are single bonds, The phenylenediamine according to [ 1 ].
[ 6 ] A phenylenediamine represented by the following general formula (1b). In the general formula (1b), R1 is hydrogen or methyl, a cyclic amino group N -cycle is represented by the following general formula (3) or general formula (4). In General Formula (3) and General Formula (4), X is O or S, n is an integer of 1 to 6, and when n is 2 or more, X may be O or S alone or a combination thereof But you can.

[ 7 ] Polyamic acid or polyimide, which is a reaction product of the phenylenediamine according to any one of [1] to [ 6 ] and tetracarboxylic dianhydride.
[ 8 ] A polyamide, which is a reaction product of the phenylenediamine according to any one of [1] to [ 6 ] and a dicarboxylic acid or a derivative thereof.
[ 9 ] A reaction product of the phenylenediamine according to any one of [1] to [ 6 ], tetracarboxylic dianhydride and dicarboxylic acid or a derivative thereof, or any one of [1] to [ 6 ] Polyamideimide, which is a reaction product of the described phenylenediamine and tricarboxylic acid or a derivative thereof.
[10] [7] varnish containing polyamic acid or polyimide according to.
[ 11 ] A varnish containing the polyamide according to [ 8 ].
[ 12 ] A varnish containing the polyamideimide according to [ 9 ].
[ 13 ] An alignment film formed using the varnish according to any one of [ 10 ] to [ 12 ].
[ 14 ] A liquid crystal display device comprising the alignment film according to [ 13 ].

The present invention can provide a novel phenylenediamine, and can provide a novel polymer (including polyamic acid, polyimide, polyamide and polyamideimide) using the phenylenediamine as a raw material. Furthermore, according to the present invention, since the phenylenediamine can be synthesized at a low cost by a short synthesis route, it is possible to provide a high-performance liquid crystal display element described below at a lower cost.
Further, according to the present invention, an alignment film capable of giving a stable pretilt angle to liquid crystal molecules can be formed in a liquid crystal display element using the varnish containing the polymer, and due to poor alignment. An alignment film that can hardly cause light leakage can also be formed. In particular, by using a varnish containing a polymer produced from phenylenediamine having a long side chain, an alignment film that can make the pretilt angle perpendicular to the liquid crystal display element can be formed.
Furthermore, according to the present invention, a liquid crystal display element having a high voltage holding ratio (VHR) and / or little image sticking can be produced using the alignment film. In particular, by using an alignment film that can make the pretilt angle vertical, a vertical alignment (VA) liquid crystal display element having excellent characteristics can be manufactured.

<Phenylenediamine of the present invention>
The phenylenediamine of the present invention is a compound represented by the general formula ( 1a ) or (1b) (hereinafter, the general formula (1a) or (1b) is also referred to as the general formula (1)) . In the general formula (1), two amino groups (—NH ₂ ) and R ¹ are each bonded to a ring carbon of a benzene ring.
In the general formula (1), R ¹ is hydrogen or methyl, preferably hydrogen. R ¹ is bonded to one of the ring carbons of the phenyl ring in which neither of the two amino groups or the amide group is bonded.

In order to increase the linearity of the main chain of the polymer obtained by reacting a diamine containing the general formula ( 1 ) with a carboxylic acid or acid anhydride described later, the two amino groups in the general formula (1) are each When the ring carbon of the phenyl ring to which the amide group is bonded is the 1-position, it is preferably bonded to the 3-position and 5-position, or the 2-position and 5-position. An alignment film formed using a polymer having a low main chain linearity (particularly a polymer having a low molecular weight) may be “scraped” by rubbing or the like, which causes alignment defects.

-N-Cycle in the general formula (1a) is a cyclic amino group, it is preferably ring cyclic amino group is a non-aromatic ring. At least one of the atoms constituting the ring of the cyclic amino group is preferably carbon. Examples of atoms constituting the ring of the cyclic amino group include nitrogen, oxygen, sulfur and the like in addition to carbon. The carbon atom constituting the ring of the cyclic amino group may have a monovalent organic group.
In addition, the number of members of the cyclic amino group is not particularly limited as long as it is 3 or more.
The alignment film prepared from phenylenediamine in which the monovalent organic group is a bulky substituent or a long-chain substituent can align liquid crystal molecules vertically in a liquid crystal display element. Therefore, in the case of forming an alignment film used for a vertical alignment (VA) liquid crystal display element, the monovalent organic group is preferably a bulky substituent or a long-chain substituent.

  Preferred examples of the cyclic amino group include an N-piperidinyl group. The ring carbon of the N-piperidinyl group (preferably the carbon at the 4-position of the piperidinyl ring) preferably has a monovalent organic group. As the N-piperidinyl group which is the cyclic amino group, a group specifically represented by the above general formula (2) is preferably exemplified.

In the general formula (2), R ² is hydrogen or alkyl having 1 to 20 (preferably 1 to 12) carbon atoms. The alkyl is a linear or branched alkyl, but is preferably a linear normal alkyl. The methylene (—CH ₂ —) constituting the alkyl may be substituted with difluoromethylene (—CF ₂ —), an ether group (—O—), or a carbonyl group (—CO—). However, none of the consecutive methylenes are substituted with an ether group (—O—) or a carbonyl group (—CO—), that is, the ether group (—O—) or the carbonyl group (—CO—) are mutually attached. It is preferable not to be adjacent.

The liquid crystal display element of the present invention produced using a phenylenediamine having an on-ring amino group (—N-Cycle) in which R ² in the general formula (2) is hydrogen or alkyl (including fluoroalkyl) is high. Has a voltage holding ratio.
Furthermore, an alignment film formed using phenylenediamine in which R ² is alkyl containing difluoromethylene (—CF ₂ —) is an alignment film formed using phenylenediamine in which R ² is alkyl not containing fluoromethylene. Compared to a film, it has a small surface energy. When the surface energy of the alignment film is reduced, the pretilt angle in the liquid crystal display element tends to increase. Therefore, when used for forming an alignment film for IPS mode or TN mode liquid crystal display elements, an amino group on the ring (—N—) in which R ² is alkyl containing difluoromethylene (—CF ₂ —). The amount of phenylenediamine having (Cycle) is preferably the minimum amount necessary.

In addition, when performing the polymer blend described later (containing a plurality of types of polymers in the varnish), if phenylenediamine having an amino group on the ring where R ² is alkyl containing fluoromethylene is used, each of the blended polymers Layers are formed, and the separated state of these layers is improved. Therefore, it is preferable to use these phenylenediamines for polymer blending for some reason.

In the general formula (2), A ¹ , A ² , and A ³ are each independently a single bond, 1,4-cyclohexylene, 1,4-phenylene, or 1,4-bicyclo [2,2,2 ] Octanylene. Of these, 1,4-cyclohexylene or 1,4-phenylene is preferable because of easy synthesis. In 1,4-phenylene, 1 to 4 (preferably 1 to 2) hydrogens on the benzene ring may be substituted with methyl, methoxy or fluorine.

One or more of A ^{1 to} A ³ is 1,4-cyclohexylene or 1,4-phenylene (unsubstituted or hydrogen on the benzene ring is substituted with methyl or fluorine (preferably fluorine). The liquid crystal display element of the present invention produced using a phenylenediamine having a cyclic amino group that is a cyclic amino group, particularly 1,4-cyclohexylene, can maintain a high voltage holding ratio, The image sticking phenomenon can be suppressed.

The alignment film formed by using a phenylenediamine having a cyclic amino group is a 1,4-phenylene in which one or more of A ¹ to A ³ is substituted by fluorine is not substituted by fluorine 1,4 Compared to an alignment film formed using phenylenediamine having a cyclic amino group which is phenylene, it has a small surface energy. Therefore, for the same reason as described above, when it is used to form an alignment film for liquid crystal display blocking use of IPS mode or TN mode, one or two or more of A ^{1 to} A ³ are substituted with fluorine. The amount of phenylenediamine having a cyclic amino group that is 4-phenylene is preferably minimized.
In addition, when polymer blending is performed for the same reason as described above, it is preferable to use these diamines in order to form layers of each polymer to be blended and improve the layer separation state.

In General Formula (2), B ¹ , B ² , and B ³ are each independently a single bond, an alkylene having 1 to 4 carbon atoms, an ether bond (—O—), an oxycarbonyl group, or an aminocarbonyl group. is there.
In the alkylene having 1 to 4 carbon atoms, any methylene (—CH ₂ —) is substituted with difluoromethylene (—CF ₂ —), an ether group (—O—) or a carbonyl group (—C (═O) —). May be. However, none of the continuous methylenes are substituted with an ether group (—O—) or a carbonyl group (—C (═O) —), that is, an ether group (—O—) or a carbonyl group (—C ( = O)-) are preferably not adjacent to each other.
The oxycarbonyl group includes both —C (═O) O— and —OC (═O) —. That is, for example, for B ¹ , a carbonyl carbon atom (or oxygen atom) may be bonded to either A ¹ or A ² .
The aminocarbonyl group includes both —C (═O) N (—R ³ ) — and —N (—R ³ ) C (═O) —. That is, for example, for B ¹ , a carbonyl carbon atom (or nitrogen atom) may be bonded to any of A ¹ and A ² .

More preferably, B ^{1 to} B ³ are each independently a single bond or ethylene (—CH ₂ CH ₂ —). Furthermore, it is particularly preferable that at least one of B ¹ and B ² is a single bond. The liquid crystal display device of the present invention B ¹ .about.B ³ was prepared using a phenylenediamine having a cyclic amino group is such a bond or a group may have a high voltage holding ratio.

As more specific examples of the cyclic amino group represented by the general formula (2), preferred are cyclic amino groups represented by (2-1) to (2-10). Furthermore, it is considered that A ^{1 to} A ³ in the general formula (2) is more preferably 1,4-cyclohexylene than phenylene, and among these, (2-1) to (2-8) ) Is more preferable, and the cyclic amino groups represented by (2-1) to (2-3) are more preferable. That is, (2-8) or (2-7) is more preferable compared with (2-10), and (2-3) is more preferable: (2-6) compared with (2-9) ) Or (2-5) is more preferred, and (2-2) is more preferred: (2-1) is more preferred compared to (2-4).
The liquid crystal display element having the alignment film of the present invention formed using phenylenediamine having such a cyclic amino group (N-Cycle) has a higher voltage holding ratio and suppresses the image sticking phenomenon.

^{R 2} in the general formula (2-1) to (2-10) has the general formula (2) is the same as ^{R 2} described in, more preferably, hydrogen or an alkyl or fluoro having 1 to 10 carbon atoms Alkyl, particularly preferably hydrogen or alkyl having 1 to 10 carbons. By using phenylenediamine having a cyclic amino group in which R ² is hydrogen or these groups, a high voltage holding ratio can be imparted to the liquid crystal display element having the alignment film of the present invention.
B ¹ and ^{B 2,} the general formula (2) is similar to ^{B 1} and ^{B 2} described in, preferably, each independently a single bond, methylene _(-CH 2 -), ether bond (- O-), ethylene _(-CH 2 _CH 2 -), oxycarbonyl group (-C (= O) O- and -OC (= O) -. including any i.e., if for example ^{B 1,} a A carbonyl carbon atom (or oxygen atom) may be bonded to any of ¹ and A ² ), or an aminocarbonyl group (—C (═O) N (—R ³ ) — and —N (—R ³ ) C (═O) — is included, that is, for example, B ¹ is a carbonyl carbon atom (or a nitrogen atom may be bonded to any of A ¹ and A ² ).
At this time, in order to impart a higher voltage holding ratio to the alignment film, B ¹ and B ² are more preferably a single bond or ethylene (—CH ₂ CH ₂ —). Moreover, it is particularly preferable that at least one of B ¹ and B ² is a single bond.

Suitable cyclic amino groups represented by the general formula (2) are illustrated more specifically in the following Table 1. In Table 1, B represents 1,4-phenylene, Ch represents 1,4-cyclohexylene, and BO represents bicyclo [2,2,2] octanylene.
In Table 1, B (3F, 5F) in A ¹ is R ² , B (3F, 5F) in A ² is B ¹ , and B (3F, 5F) in A ³ is B ^2. On the other hand, it represents 1,4-phenylene in which the hydrogen in the 3,5-position is substituted with fluorine. B (2F, 6F) represents 1,4-phenylene in which hydrogen at the 2,6-position is substituted with fluorine for R ² .
The liquid crystal display device comprising an alignment layer formed using the phenylenediamine having cyclic amino group (general formula (1a) -N-Cycle in) illustrated in Table 1, high voltage holding ratio, burn is inhibited In addition, the liquid crystal may have characteristics such as vertical alignment.

No. in Table 1 A polymer (polyamic acid, polyimide, polyamide, or polyamide) having 1 to 30 cyclic amino groups (all of which A ² , A ³ , B ² , and B ³ are all single bonds) synthesized from at least one raw material The alignment film formed using a varnish containing (including polyamideimide) can adjust the pretilt angle to about 5 to 10 degrees in the liquid crystal display element. Therefore, it is particularly suitable as a phenylenediamine used for forming an alignment film for TN.

No. in Table 1 Synthesized polymers phenylenediamine with 30-154 cyclic amino group (formula (-N-Cycle in 1a)) as a raw material formed by using a varnish containing (polyamic acid, polyimide, including polyamide or polyamideimide) The alignment film thus formed can maintain a pretilt angle close to 90 degrees in the liquid crystal display element, and the pretilt angle is very stable. Therefore, it is particularly suitable as a phenylenediamine used for forming an alignment film for a vertical alignment (VA) type liquid crystal display element that requires a pretilt angle close to perpendicular to the substrate.
In addition, a liquid crystal display element having an alignment film formed using a varnish containing a polymer synthesized using at least one of these phenylenediamines as a raw material has a high voltage holding ratio (VHR). However, it is particularly suitable.

On the other hand, as -N-Cycle in General Formula ( 1b ), the cyclic amino group represented by the said General formula (3) or General formula (4) is also illustrated preferably.

  In the cyclic amino group represented by formula (3) or formula (4), X is O or S, and n is an integer of 1 to 6. Preferably, in the cyclic amino group represented by the general formula (3) or the formula (4), n = 2 to 6 is preferable, and n = 3 to 5 is more preferable. The cyclic amino group represented by the formula (3) or (4) is preferably capable of selectively incorporating ions into the ring, and the value of n depends on the ion to be incorporated (for example, depending on the ion radius). May be appropriately selected.

  In addition, when the ion to be incorporated is an alkali metal ion, an alkaline earth metal ion, or an ammonium ion, it is preferable to select an oxygen atom (O) as X, and when the ion to be incorporated is another metal ion, It is preferable to select a sulfur atom (S) as at least one X.

  Preferable specific examples of the cyclic amino group represented by the general formula (3) or the formula (4) include groups represented by the following structural formulas (No. 155 to No. 163).

As described above, the phenylenediamine having a cyclic amino group (—N-Cycle) represented by the general formula (3) or (4) supplements a metal ion or an ammonium ion in the ring of the —N-Cycle site. can do. Accordingly, in a liquid crystal display element including an alignment film formed from a varnish containing a polymer (including polyamic acid, polyimide, polyamide, or polyamideimide) synthesized from this phenylenediamine as a raw material, from the ions in the liquid crystal or the alignment film The ions extracted into the liquid crystal can be removed by the alignment film. It is known that ions in the liquid crystal contribute to a decrease in voltage holding ratio (VHR) of the liquid crystal display element and a burn-in phenomenon. Therefore, for the purpose of improving these characteristics, the liquid crystal display element of the present invention can be produced using phenylenediamine having a cyclic amino group represented by the general formula (3) or formula (4).
Preferably, the liquid crystal display element of the present invention having an alignment film obtained from a phenylenediamine having a cyclic amino group represented by the general formula (3) or formula (4) does not have a low voltage holding ratio and is burned. Is suppressed, and the ion density in the liquid crystal is reduced.

  The phenylenediamine (the compound represented by the general formula (1)) of the present invention can be produced by any method, and can be synthesized by a method as shown in the following scheme 1, for example.

The compound represented by the formula (1-a) in Scheme 1 is a cyclic amine compound, and can be synthesized according to the method described in DE 4234627A1, for example. The compound represented by formula (1-b) is benzoyl chloride having two nitro groups and R ¹ (which is hydrogen or methyl) on the phenyl ring, and can be synthesized according to the method described in, for example, WO9631462. it can.

  The compound represented by the formula (1-c) can be synthesized by reacting the compound represented by the formula (1-a) with the compound represented by the formula (1-b) in the presence of a base. it can. As the base to be used, organic amines such as triethylamine and pyridine can be preferably used, but other bases (for example, sodium carbonate and the like) can also be used. In the reaction, a reaction solvent may be used, and a halogen-based solvent such as methylene chloride is preferably used, but other aprotic solvents (for example, tetrahydrofuran, dimethylformamide, etc.) can also be used. The reaction temperature is usually room temperature or lower, but may be appropriately selected.

  A compound represented by the formula (1) can be obtained by subjecting the obtained compound represented by the formula (1-c) to a hydrogenation reaction according to a conventional method. The hydrogenation reaction is a catalytic hydrogenation reaction using Pd—C as a catalyst, for example.

  The production method of the compound represented by the formula (1) (phenylenediamine of the present invention) is not limited to the above method. Further, the synthesis of the compound represented by the formula (1) has been described in more detail in the examples described later.

A polymer can be produced by reacting the compound represented by formula (1) (the phenylenediamine of the present invention) with a carboxylic acid or an acid anhydride. For example, the following polymers can be produced.
1) A polyamic acid can be obtained by reacting a compound represented by the formula (1) with an acid dianhydride (for example, tetracarboxylic dianhydride), and a polyamic acid is further subjected to a dehydration reaction. Can be obtained.
2) A polyamideimide can be obtained by reacting a compound represented by the formula (1) with a mixture of an acid dianhydride (for example, tetracarboxylic dianhydride) and a dicarboxylic acid, or a tricarboxylic acid or a derivative thereof. it can.
3) A polyamide can be obtained by reacting the compound represented by the formula (1) with a dicarboxylic acid or a derivative thereof.

  In the production of the polymer, the compound represented by the formula (1) may be reacted alone or in combination of two or more. Moreover, in manufacture of the said polymer, phenylenediamine represented by Formula (1) and diamine other than the compound represented by Formula (1) can also be made to react.

  As described above, in the production of the polymer, the compound represented by the formula (1) (the phenylenediamine of the present invention) can be reacted in combination with other diamines. Any known diamine may be mentioned and is not particularly limited. Particularly preferred examples include the diamines listed in Table 2.

  In the production of the polymer, examples of the diamine that can be used in combination with the phenylenediamine of the present invention include siloxane-based diamines represented by the general formula (5) in addition to the diamines shown in Table 2 above.

In the general formula (5), R ¹⁰ and R ¹¹ are alkyl or phenyl having 1 to 3 carbon atoms, and R ¹⁰ and R ¹¹ may be the same group or different groups. R ¹² is methylene, phenylene or alkyl-substituted phenylene. m is an integer of 1-6, and n is an integer of 1-10.

  In addition, the phenylenediamine compound of the present invention is not only used as a raw material for a resin for alignment films of liquid crystal display elements (for example, polyimide resin), but various polyimide coating agents, polyimide resin molded products, films, fibers, etc. It can be used as a raw material. Furthermore, it can be used as a raw material for polyamide resin, polyamideimide resin, polyurea resin, or a curing agent for epoxy resin.

<Polymer of the present invention>
Next, the polyamic acid, polyimide, polyamide, and polyamideimide of the present invention (these are collectively referred to as “the polymer of the present invention”) will be described. The polymer of the present invention is a polymer compound that can be produced using the compound represented by the formula (1) described above (phenylenediamine of the present invention) as a raw material.

As described above, the polyamic acid of the present invention is a compound obtained by reacting phenylenediamine represented by the formula (1) with an acid dianhydride (for example, tetracarboxylic dianhydride). The polyimide of the present invention can be obtained by dehydrating the polyamic acid. The polyamideimide of the present invention can be obtained by reacting a phenylenediamine represented by the formula (1) with a mixture of an acid dianhydride (for example, tetracarboxylic dianhydride) and a dicarboxylic acid. The polyamideimide of the present invention can also be obtained by reacting phenylenediamine represented by the formula (1) with tricarboxylic acid or a derivative thereof. The polyamide of the present invention can be obtained by reacting the phenylenediamine represented by the formula (1) with a dicarboxylic acid or a derivative thereof.
The acid dianhydride, dicarboxylic acid and derivatives thereof, and tricarboxylic acid or derivatives thereof to be reacted with the phenylenediamine represented by the formula (1) are also collectively referred to as “carboxylic acids”.

In view of solubility in a solvent, printability, and the problem of abrasion described above, the weight average molecular weight of the polymer of the present invention is 1 × 10 ³ to 1 × 10 ⁶ (more preferably 1 × 10 ⁴ to 1 × 10 ⁵ ). It is preferable that The weight average molecular weight of the polymer of the present invention can be measured by the method described in the Examples below.

  Examples of the tetracarboxylic dianhydride used in the production of the polymer of the present invention (for example, polyamic acid, polyimide, polyamide, polyamideimide) include any known tetracarboxylic dianhydride. And compounds described in Table 3.

Of the acid dianhydrides shown in Table 3 above, no. 2-2, 2-12, 2-13, 2-14, 2-15, 2-16, 2-17, 2-18, 2-20, 2-21, 2-22, 2-23, 2- One or more types of acid dianhydrides having an alicyclic skeleton such as 24, 2-28, 2-29, 2-30, 2-31, 2-32, and 2-38 may be preferably selected.
A varnish is prepared using a polymer obtained by reacting such an acid dianhydride (may be a mixture) and a compound represented by the general formula (1) (the phenylenediamine of the present invention), and this varnish is used. In the case where an alignment film is formed over a substrate and a liquid crystal display element including the alignment film is manufactured, the liquid crystal display element has a high voltage holding ratio (VHR).

  Of the acid dianhydrides shown in Table 3, No. Acid dianhydrides such as 2-1, 2-3, 2-4, 2-5, 2-6, 2-7, 2-8, 2-9, 2-10, 2-11, 2-19, etc. It can be preferably selected. Polymers obtained by appropriately combining these acid dianhydrides and other compounds (for example, dicarboxylic acid or tricarboxylic acid or derivatives thereof) and reacting with the compound (phenylenediamine) represented by the general formula (1) When a varnish containing is prepared and an alignment film is formed on the substrate using the varnish to produce a liquid crystal display element including the alignment film, the image sticking phenomenon of the liquid crystal display element is suppressed.

Some of the carboxylic acids that can be reacted with the phenylenediamine represented by the general formula (1) have isomers (including enantiomers), but the isomers alone or as a mixture of isomers are represented by the formula (1). It can be made to react with the phenylenediamine represented by these. Further, one kind of carboxylic acid may be used alone, or two or more kinds of carboxylic acids may be used in combination.
Needless to say, the carboxylic acids (including tetracarboxylic dianhydride) used in the present invention are not limited to the above compounds.

  The polymer of the present invention is produced by reacting a diamine with a carboxylic acid (such as an acid dianhydride, a dicarboxylic acid, or a tricarboxylic acid) except that the phenylenediamine represented by the general formula (1) is used as at least one raw material. can do. A method for producing a polymer by the reaction of a diamine and a carboxylic acid is described in detail in “New Polymer Experimental Science 3, Polymer Synthesis (2), Kyoritsu Publishing Co., Ltd., 1996”. It is also described in examples described later.

<Varnish of the present invention>
The varnish of the present invention is a polymer of the present invention (polyamic acid, polyimide, polyamide, polyamideimide, etc.) produced from the above-described phenylenediamine (which may contain other diamines) and carboxylic acids (for example, acid dianhydrides). Is a polymer solution containing one or more selected from. Moreover, the varnish of this invention can also contain polymers other than the polymer of this invention, and arbitrary components (an organic silicone compound etc.).

  The solvent for the varnish of the present invention is not particularly limited, but is preferably a solvent that dissolves the polymer of the present invention. Examples include N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), ethylene glycol monobutyl ether (BC), ethylene glycol monoethyl ether, and γ-butyrolactone. be able to. The solvent of the varnish of the present invention may be one type of solvent, but may be a mixed solvent of two or more types of solvents.

When the varnish is applied to the substrate by a spinner method or a printing machine, the viscosity of the varnish of the present invention is preferably 10 to 100 mPa · s (more preferably 20 to 50 mPa · s) from the viewpoint of printability. In the case of coating by a recently performed ink jet method, it is preferably 1 to 30 mPa · s (more preferably 5 to 20 mPa · s). The viscosity of the varnish of the present invention may be outside the above range depending on the coating conditions.
The viscosity can be measured based on the method described in the examples below.

  The varnish of the present invention can be used for forming an alignment film, a protective film, an insulating film and the like, but is particularly useful as a varnish for forming an alignment film for a liquid crystal display element. The liquid crystal display element having an alignment film formed from the varnish of the present invention has a high VHR, can prevent a burn-in phenomenon, and can have a high liquid crystal alignment ability. Therefore, the varnish of the present invention contains a liquid crystal composition having a low threshold voltage, and is particularly useful for forming an alignment film for a TFT display device that is driven at a low voltage.

  Further, the varnish of the present invention may contain only one kind of the polymer of the present invention, but two or more kinds may be arbitrarily mixed and used (a varnish in which such a plurality of polymers are blended is used. Also called “polymer blend varnish”). The polymer-blended varnish can impart desired characteristics to the alignment film formed using the varnish.

For example, the varnish of the present invention is preferably a varnish in which polyamide or polyamideimide and polyamic acid or polyimide are polymer blended. In a liquid crystal display device having an alignment film formed using such a polymer-blended varnish, a decrease in VHR can be suppressed, and thermal and mechanical stability of alignment can be improved.
At this time, the addition amount of polyamide or polyamideimide or a mixture thereof is preferably 0.01 to 30% by weight, and preferably 0.01 to 10% by weight with respect to polyamic acid or polyimide or a mixture thereof. Is more preferable.

Furthermore, in order to develop better properties as an alignment film, the varnish of the present invention may be a varnish obtained by polymer blending the polymer of the present invention and one or more kinds selected from known arbitrary polymers. Examples of known polymers include other polymer compounds such as known polyamideimides and polyamides.
At this time, the proportion of the polymer of the present invention in the total polymer is 50% in order to effectively express the effects of the present invention (including providing a liquid crystal display element with improved voltage holding ratio and image sticking). The range of ˜about 100% by weight is preferred and the range of 70˜about 100% by weight is more preferred.

  The proportion of the polymer contained in the varnish of the present invention is not particularly limited. As described below, a varnish coating method (brush coating method, dipping method, spinner) selected for forming the alignment film on the substrate is used. Method, spray method, printing method, etc.), an optimal value may be selected as appropriate. Usually, in order to suppress unevenness and pinholes during coating, the ratio of the polymer to the varnish weight is preferably 0.1 to 30% by weight, more preferably 1 to 10% by weight.

The varnish of this invention can contain arbitrary components other than a polymer.
For example, by adding an organosilicone compound to the varnish of the present invention, it is possible to adjust the adhesion and hardness of the alignment film formed using the varnish to the glass substrate. In addition, when the formed alignment film is subjected to an alignment process (including a rubbing process), display defects caused by the alignment film being scraped can be improved.

  The organic silicone compound contained in the varnish of the present invention is not particularly limited. For example, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, vinyltrimethoxysilane, N- (2-aminoethyl) -3 -Aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3- Examples include silane coupling agents such as glycidoxypropylmethyldimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and silicone oils such as dimethylpolysiloxane, polydimethylsiloxane, and polydiphenylsiloxane. It is.

  The content of the organosilicone compound in the varnish is not particularly limited as long as the display defect can be improved without impairing the properties required for the alignment film. However, when the content of the organosilicone compound in the varnish increases, liquid crystal alignment defects tend to occur in the formed alignment film. Therefore, the concentration of the organic silicone compound in the varnish of the present invention is preferably 0.01 to 5% by weight, particularly preferably 0.1 to 3% by weight, based on the weight of the polymer contained in the varnish. is there.

  The varnish of the present invention includes 1) a polymer solution obtained by reacting the phenylenediamine of the present invention and a carboxylic acid (including acid dianhydride) in a solvent (that is, a reaction solution), and 2) Further, it may be a solution obtained by adding and diluting a solvent, and 3) a solution obtained by dissolving a polymer obtained by removing the solvent from the reaction solution in another solvent.

<Alignment film of the present invention>
Fourth, the alignment film of the present invention will be described. The alignment film of the present invention is an alignment film formed on a substrate using the varnish of the present invention described above. The alignment film of the present invention may be formed using one selected from the varnishes of the present invention, and is formed using a mixture of two or more varnishes as described above. It may be a thing.

The alignment film of the present invention is formed on a substrate, but the formation method is not particularly limited. For example, a method having the following steps can be exemplified.
(1) The varnish of the present invention is applied on a substrate by a brush coating method, a dipping method, a spinner method, a spray method, a printing method or the like.
(2) The solvent is evaporated at 50 to 150 ° C, preferably 80 to 120 ° C.
(3) The film is formed by heating at 150 to 400 ° C., preferably 180 to 280 ° C.
(4) The film surface is rubbed with a cloth or the like.
If the substrate surface is treated with a silane coupling agent or the like before the varnish is applied and an alignment film is formed thereon, the adhesion between the alignment film and the substrate is improved.

  The thickness of the alignment film of the present invention can be variously selected depending on the manufacturing conditions of the display element in order to satisfy the characteristics required for the alignment film described above, but generally the thickness is 10 to 200 μm. preferable.

The alignment film of the present invention is formed using a varnish, but the varnish may be a polymer-blended varnish as described above. Therefore, by forming an alignment film using a varnish that is a blend of a component having a low surface tension and a component having a high surface tension, an alignment film in which components having a low surface tension are segregated on the film surface can be obtained. (It is described in Kaihei 8-43831).
Therefore, a fluorine atom is introduced into the polymer (polyamic acid or polyimide) of the present invention having a low surface tension (for example, a cyclic amino group of phenylenediamine represented by formula (1) (preferably represented by formula (2)). If the varnish is used, the polymer component of the present invention is concentrated on the film surface. An alignment film that effectively expresses stable liquid crystal alignment characteristics, which is one of the characteristics of the present invention, can be obtained.
Alternatively, the surface tension of the polymer of the present invention having a high surface tension (for example, the cyclic amino group of phenylenediamine represented by the formula (1) (preferably represented by the formula (2) is preferably substituted). In combination with a polymer having a low surface tension (which can be a known polymer), the polymer component of the present invention is concentrated inside the film, which is an excellent feature of the present invention. Electrical characteristics (suppression of burn-in, high voltage holding ratio, etc.) can be effectively expressed.
Of course, both a low surface tension polymer and a high polymer may be used as the polymer of the present invention.
In this manner, a layer having excellent liquid crystal alignment characteristics can be formed on the film surface of the alignment film of the present invention, and a layer having excellent electrical characteristics can be formed in the bulk. Can be formed.

  The mixing ratio of the polymer having a lower surface tension (hereinafter referred to as polymer 1) and the polymer having a higher surface tension can be arbitrarily selected between 1 wt% and 99 wt%, respectively. However, in order to develop good electrical properties while maintaining good liquid crystal alignment properties and a pretilt angle, it is preferable to add 1 to 30% by weight of polymer 1 with respect to the total polymer weight, It is more preferable to add between 5 and 15% by weight.

<Liquid Crystal Display Device of the Present Invention>
Fifth, a liquid crystal display element including the alignment film of the present invention (hereinafter also referred to as “liquid crystal display element of the present invention”) will be described. The liquid crystal display element of this invention can be set as the structure similar to arbitrary well-known liquid crystal display elements except including the alignment film of this invention as an alignment film.

The liquid crystal display element of the present invention has advantageous characteristics such as a high voltage holding ratio, improved image sticking, and stable liquid crystal orientation. Therefore, the liquid crystal display element of the present invention is, for example, TFT
The liquid crystal display element is preferably used. Since the liquid crystal display element for TFT is required to have a particularly high voltage holding ratio and the need to improve the image sticking is high, the effect of the alignment film included in the liquid crystal display element of the present invention works particularly effectively.
The liquid crystal composition used for the liquid crystal display element for TFT is described in Japanese Patent No. 3086228, Japanese Patent No. 2635435, Japanese Patent Laid-Open No. 5-501735, Japanese Patent Laid-Open No. 9-255956, and the like. The liquid crystal display element of the present invention preferably uses the liquid crystal composition described therein.

  In a preferred embodiment, the liquid crystal display element of the present invention is also advantageous as a vertical alignment (VA) liquid crystal display element. Since the VA liquid crystal display element needs to have a large pretilt angle, the alignment film included in the liquid crystal display element of the present invention can act particularly effectively.

<Example>
Hereinafter, the synthesis of the phenylenediamine of the present invention, the synthesis of the polymer of the present invention from phenylenediamine, the preparation of the varnish containing the polymer, the formation of the liquid crystal alignment film using the varnish, and the liquid crystal alignment film are included according to examples. The production of the liquid crystal display element will be specifically described. The scope of the present invention is not limited by these examples.

  In Examples, all NMR was measured using deuterated chloroform as a solvent (500 MHz). The molecular weight was measured using GPC using polystyrene as a standard solution and DMF as an eluent. The viscosity was measured using a rotational viscometer (manufactured by Toki Sangyo Co., Ltd., TV-20).

<Examples 1 to 5: Synthesis of phenylenediamine>
Example 1: 1- (3,5-diaminobenzoyl) -4-n-propylpiperidine (in formula (1), the diamine is in the 3,5-position with respect to the amide group, R ¹ is hydrogen, N -Cycle is a cyclic amino group represented by the general formula (2), in the general formula (2) ^{R 2} is ^{propyl, a 1, a 2, a} 3, B 1, B 2, and ^{B 3} Of compounds in which is a single bond)

In a solution of 7.0 g (55 mmol) of 4-n-propylpiperidine synthesized according to the method described in DE 4234627A1 and 6.7 g (66 mmol) of triethylamine in methylene chloride (100 ml), 14 g (60 mmol) of 3,5-dinitrobenzoic acid chloride. ) Was added below room temperature. After stirring at room temperature for 3 hours, pure water (30 ml) was added. After the organic layer was separated, the organic layer was further washed with pure water (30 ml). The obtained organic layer was dried over anhydrous magnesium sulfate and then filtered, and the solvent of the obtained filtrate was distilled off under reduced pressure. By subjecting the obtained residue to column chromatography (silica gel / toluene: ethyl acetate = 10: 1) and recrystallization (ethanol), the desired 1- (3,5-nitrobenzoyl) -4-n-pull is obtained. Pilpiperidine was obtained. Yield 14 g (82% yield).
By subjecting 10 g (31 mmol) of the obtained compound to a hydrogenation reaction in toluene: ethanol (1: 1, v / v) solvent (100 ml) using Pd / C (5%: 500 mg) as a catalyst, the desired 1 -(3,5-Diaminobenzoyl) -4-n-purpyrpiperidine was obtained. Yield 5.4 g (66% yield).

Example 2: 1- (3,5-Diaminobenzoyl) -4- (2- (4-n-propylcyclohexyl) ethyl) piperidine (in the general formula (1), the diamine is in the 3,5-position with respect to the amide group) R ¹ is hydrogen, N-Cycle is a cyclic amino machine represented by the general formula (2), R ² is propyl in the general formula (2), and A ¹ is 1,4- Compound in which cyclohexyl, B ¹ is ethylene, and A ² , A ³ , B ² , and B ³ are single bonds

  The compound was synthesized in the same manner as in Example 1 except that 4- (2- (4-n-propylcyclohexyl) ethyl) piperidine was used instead of 4-n-propylpiperidine.

Example 3: 1- (3,5-Diaminobenzoyl) -4- (4- (4-n-propylcyclohexyl) cyclohexyl) piperidine (in formula (1), the diamine is in the 3,5-position with respect to the amide group) R ¹ is hydrogen, N-Cycle is a cyclic amino group represented by the general formula (2), R ² is propyl in the general formula (2), and A ¹ and A ² are 1, 4-cyclohexyl compound in which A ³ , B ¹ , B ² , and B ³ are single bonds

  The compound was synthesized in the same manner as in Example 1 except that 4- (4- (4-n-propylcyclohexyl) cyclohexyl) piperidine was used instead of 4-n-propylpiperidine.

Example 4: 1- (3,5-diaminobenzoyl) -4- (2- (4- (4-n-pentylcyclohexyl) cyclohexyl) ethyl) piperidine (3 in the general formula (1) with respect to the amide group , 5-position, R ¹ is hydrogen, N-Cycle is a cyclic amino group represented by general formula (2), R ² is pentyl in general formula (2), and A ¹ and Compound in which A ² is 1,4-cyclohexylene, A ³ , B ¹ , and B ³ are single bonds, and B ² is ethylene)

The compound was synthesized in the same manner as in Example 1 except that 4--4- (2- (4- (4-n-pentylcyclohexyl) cyclohexyl) ethyl) piperidine was used instead of 4-n-propylpiperidine.
Melting point: 257.8-258.8 ° C.
¹ H-NMR δ (ppm); 6.08 (d, 2H, d = 1.85 Hz), 6.02 (d, 1H, d = 1.85 Hz), 4.62-4.64 (m, 1H) 3.6-3.80 (m, 1H), 3.4-3.9 (brs, 4H), 2.80-2.89 (m, 1H), 2.64-2.78 (m, 1H), 0.80-1.90 (m, 39H).

Example 5: N- (3,5-diaminobenzoyl) -1-aza-15-crown-5 (in general formula (1), the diamine is in the 3,5-position with respect to the amide group and R ¹ is hydrogen N-Cycle is a cyclic amino group represented by the general formula (3), and in the general formula (3), X is all O and n is 4.

  Synthesis was performed in the same manner as in Example 1 except that commercially available 1-aza-15-crown-5 was used instead of 4-n-propylpiperidine.

<Examples 6 to 16: Synthesis of polymer and preparation of varnish>
Example 6: Synthesis of polyamic acid 1- (3,5-diaminobenzoyl) -4- (2- (4-n-propylcyclohexyl) ethyl) piperidine synthesized in Example 2 was added to a 100 ml four-necked flask. .5752 g (4.2396 mmol) was added and dissolved in 25 g of NMP. Pyromellitic anhydride (PMDA) 0.9247 g (4.240 mmol) was added thereto and stirred at 20 ° C. for 1 hour. Thereafter, this solution was diluted with 22.5 g of BC (ethylene glycol monobutyl ether) to obtain a transparent solution of about 5% by weight of polyamic acid. The weight average molecular weight of this polyamic acid was 82,000. The viscosity of this solution at 25 ° C. was 43 mPa · s. Hereinafter, this solution is referred to as varnish A.

Example 7 Synthesis of Polyamide 3.7156 g of 1- (3,5-diaminobenzoyl) -4- (2- (4-n-propylcyclohexyl) ethyl) piperidine synthesized in Example 2 in a three-necked flask (500 ml).
(10.00 mmol), 4,4′-diaminodiphenylmethane (DDM) 0.9913 g (5.000 mmol), terephthalic acid (TPA) 2.4920 g (15.00 mmol), and lithium chloride 3.8 g (88 mmol) , Dissolved in NMP (120 ml). To this, 11.8 g (38 mmol) of triphenyl phosphite was added dropwise and reacted at 100 ° C. for 4 hours in a nitrogen stream. After cooling, the reaction product was added to 1 L of methanol to precipitate a polymer, which was collected by filtration. This crude product was boiled and washed twice with 500 ml of pure water and once with 500 ml of methanol for about 30 minutes each. Vacuum drying was performed at 120 ° C. for 7 hours to obtain 5.8 g of polyamide. The weight average molecular weight of this polyamide was 130,000.

  In a three-necked flask, 5.0 g of the above polyamide was placed and dissolved in NMP (75 ml). To this, 1.89 g (35 mmol) of sodium methoxide was added and stirred at room temperature for 3 hours. To this solution, 5.4 g (38 mmol) of methyl iodide was added, and further reacted at room temperature for 2 hours. The reaction product was re-precipitated in 0.5 L of pure water, collected by filtration, and boiled and washed twice with 250 mL of pure water for 30 minutes each, and then purified water / IPA (2-propanol) (1/1 w / w) Washed once with 120 ml of mixed solvent. It was vacuum-dried at 120 ° C. for 8 hours to obtain 4.6 g of polymethylamide. The polymethylamide had a weight average molecular weight of 63,000, and the substitution rate of amide hydrogen to a methyl group was 100% from NMR measurement.

Example 8: Synthesis of polyamideimide 3.7156 g of 1- (3,5-diaminobenzoyl) -4- (2- (4-n-propylcyclohexyl) ethyl) piperidine synthesized in Example 2 in a three-necked flask (500 ml). (10.00 mmol), 0.913 g (5.000 mmol) of DDM, and 1.3 g (16 mmol) of pyridine were dissolved in NMP (50 ml) and 3.1585 g of trimellitic acid chloride anhydride (TMAClA) (15 0.000 mmol) was added and allowed to react overnight at room temperature. To this reaction solution, 1.53 g (15.0 mmol) of acetic anhydride and 1.19 g (15.0 mmol) of pyridine were added and reacted at 100 ° C. for 1 hour. After cooling, the reaction was added to 250 mL of methanol to reprecipitate the polymer, which was collected by filtration. This crude product was boiled and washed for about 30 minutes, twice with 250 ml of pure water and once with 250 ml of methanol. Vacuum drying at 120 ° C. for 7 hours gave 6.2 g of polyamideimide. The weight average molecular weight of this polyamideimide was 48,000.

  The polyamideimide 5.0g was put into the three necked flask, and it was made to melt | dissolve in NMP (75 ml). Sodium methoxide 0.95g (18mmol) was added here, and it was made to stir at room temperature for 3 hours. To this solution, 2.0 g (14 mmol) of methyl iodide was added and further reacted at room temperature for 2 hours. The reaction product was re-precipitated in 0.5 L of pure water, collected by filtration, then boiled and washed twice with 250 mL of pure water for 30 minutes each, and then purified water / IPA (2-propanol) (1/1 w / w ) Washed once with 120 ml of mixed solvent. Vacuum drying at 120 ° C. for 8 hours gave 4.1 g of polymethylamidoimide. This polymethylamidoimide had a weight average molecular weight of 25,000, and the substitution rate of amide hydrogen to a methyl group was 93% as measured by NMR.

Examples 9 to 12: Synthesis of polyamic acid The diamines of Examples 1, 3, 4, and 5 were used in place of the diamine of Example 2 (corresponding to Examples 9, 10, 11, and 12, respectively). A clear solution of about 5% by weight of polyamic acid was obtained in the same manner as in Example 6. Table 4 shows the molecular weight of the polyimide acid obtained in Examples 9 to 12 and the viscosity of the solution at 25 ° C. In addition, let the solutions obtained in Examples 9-12 be varnish B, C, D, and E, respectively.

Examples 13 to 16: Synthesis of polyamic acid A transparent solution of about 5% by weight of polyamic acid was obtained in the same manner as in Example 6 except that the diamine described below was used instead of the diamine of Example 2. Table 4 shows the molecular weight of the polyimide acid obtained in Examples 13 to 16 and the viscosity of the solution at 25 ° C. In addition, let the solutions obtained in Examples 13-16 be varnish F, G, H, and I, respectively.
Example 13: A mixture of the diamine of Example 1 and 4,4-diaminodimethane (DDM) (Example 1: DDM = 90: 10 (molar ratio)) was used.
Example 14: A mixture of the diamine and DDM of Example 2 (Example 2: DDM = 30: 70 (molar ratio)) was used.
Example 15: A mixture of the diamine and DDM of Example 3 (Example 3: DDM = 90: 10 (molar ratio)) was used.
Example 16: A mixture of the diamine and DDM of Example 4 (Example 4: DDM = 90: 10 (molar ratio)) was used.

<Comparative Examples 1-3: Synthesis of polyimide acid>
Comparative Example 1; except that DDM was used instead of the diamine of Example 2, and a mixture of PMDA and 1,2,3,4-cyclobutanetetracarboxylic dianhydride (molar ratio 50:50) was used instead of PMDA Obtained a clear solution of about 5% by weight of polyamic acid in the same manner as in Example 6.
Comparative Example 2; 3,5-diaminobenzoic acid 4-n-pentylcyclohexylphenolate (hereinafter abbreviated as “5ChBEB”; synthesized according to the method described in WO9730107) and DDM instead of the diamine of Example 2. A clear solution of about 5% by weight of polyamic acid was obtained in the same manner as in Example 6 except that the mixture (molar ratio 90:10) was used.
Comparative Example 3; a transparent polyamic acid of about 5% by weight in the same manner as in Example 6 except that the above compound (7) (see JP-A No. 2002-327058) was used instead of the diamine of Example 2. A solution was obtained.
Table 4 shows the molecular weight of the polyamic acid obtained in Comparative Examples 1 to 3 and the viscosity of the solution at 25 ° C. In addition, the solution obtained in Comparative Examples 1-3 is set to varnish J-L, respectively.

<Examples 17 to 23: Formation of alignment film of the present invention and production of liquid crystal display element>
Example 17
In a three-necked flask, 1.82 ml and 18.2 ml of varnish C and varnish J were weighed and stirred at room temperature for 1 hour. Thereafter, 12 ml of BC was added to obtain about 3% by weight of a resin composition. This composition was dropped onto a transparent glass substrate provided with an ITO electrode on one side and applied by a spinner method (2500 rpm, 15 seconds). After application, the solvent was evaporated at 80 ° C. for 5 minutes, and then heat treatment was performed in an oven at 250 ° C. for 30 minutes to form a resin film having a thickness of about 60 nm. Two glass substrates on which the resin film (that is, the alignment film) was formed were combined to assemble a liquid crystal cell having a cell thickness of 20 μm. Liquid crystal composition A shown in the following table was injected into this cell, subjected to an isotropic treatment at 110 ° C. for 30 minutes, and cooled to room temperature to obtain a liquid crystal display device.

Example 18
In Example 17, the resin film was rubbed under the following conditions, and a liquid crystal cell was assembled so that the rubbing direction was antiparallel. Thereafter, a liquid crystal display element was produced in the same manner as in Example 17.
(Rubbing condition; hair tip indentation amount: 0.4 mm, roller rotation speed: 300 rpm, roller feed speed: 30 mm / sec, frequency: once)

Example 19
A liquid crystal display device was produced in the same manner as in Example 17 except that varnish D was used instead of varnish C.

Examples 20 and 21
A liquid crystal display device was produced in the same manner as in Example 17 except that the varnish C was changed to the following varnish.

Comparative Example 4
A liquid crystal display device was produced in the same manner as in Example 17 except that varnish K was used instead of varnish C.

Comparative Example 5
A liquid crystal display device was produced in the same manner as in Example 17 except that varnish L was used instead of varnish C.

Example 22
A liquid crystal display device was produced in the same manner as in Example 18 except that varnish G was used instead of varnish C, and liquid crystal composition B shown in Table 6 below was used instead of liquid crystal composition A.

Example 23
A liquid crystal display device was produced in the same manner as in Example 22 except that a mixture of varnish E and varnish J in a weight ratio of 1:10 was used instead of varnish J.

<Test example>
Regarding the liquid crystal display devices manufactured in Examples 17 to 23 and Comparative Examples 4 and 5, 1) pretilt angle, 2) image sticking (residual charge), 3) voltage holding ratio, 4) orientation, 5) ion amount in liquid crystal (Ion density) was measured or evaluated. The measurement method or evaluation method for each is as follows.

Evaluation method of liquid crystal display element Pretilt angle Measured by the crystal rotation method.
2. Burn-in (residual charge)
Residual DC voltage was measured by superimposing 50 mV, 1 kHz alternating current and 0.0036 Hz direct current triangular wave on the liquid crystal cell by the method described in “Miyake et al., Shingaku Giho, EID91-111, p19”. This residual charge was used as an index for image sticking. In other words, the more residual charge, the easier it is to burn.
3. Voltage holding ratio It measured by the method as described in "Mizushima et al. The measurement conditions were a gate width of 69 μs, a frequency of 60 Hz, and a wave height of ± 4.5V.
4). Orientation Evaluated by visual observation under a polarizing microscope.
5). Measurement of ion content in liquid crystal (ion density)
According to the method described in Applied Physics, Vol. 65, No. 10, 1065 (1996), measurement was performed using a liquid crystal property measuring system 6254 type manufactured by Toyo Technica. Measurement was performed in a voltage range of ± 10 V using a triangular wave with a frequency of 0.01 Hz.

<Test Example 1: Test of liquid crystal display elements of Examples 17 to 21 and Comparative Examples 4 to 5>
(Test on liquid crystal display element of Example 17)
About the liquid crystal display element of Example 17
As a result of measuring the residual DC at 25 ° C., it was 123 mV.
As a result of measuring the voltage holding ratio (VHR) at 20 ° C., 60 ° C. and 90 ° C., they were 99.2%, 98.7% and 96.8%, respectively.
The pretilt angle was measured and found to be 90 degrees.
As a result of observation with a polarizing microscope, no light penetration due to orientation failure was observed. These results are shown in Table 7 as Condition: Initial.

  Next, the liquid crystal display element of Example 17 was allowed to stand at 110 ° C. for 20 hours, and then cooled to room temperature. After cooling, the same measurement and observation were performed again. As a result, the residual DC was 132 mV (25 ° C.), the VHR was 99.0 (20), 98.4 (60), 96.7% (90 ° C.), and the pretilt angle was 90 degrees. Furthermore, as a result of observation with a polarizing microscope, no light penetration due to poor alignment was observed. These results are shown in Table 7 as Condition: After high temperature.

(Test on liquid crystal display elements of Examples 18 to 21 and Comparative Examples 4 to 5)
The liquid crystal display elements of Examples 18 to 21 and Comparative Examples 4 to 5 were measured and observed in the same manner as the liquid crystal display element of Example 17. The results are shown in Table 7.

As shown in Table 7, the liquid crystal display elements of Examples 17 to 21 had smaller residual DC and higher voltage holding ratio (VHR) than the liquid crystal display elements of Comparative Examples 4 and 5, and the liquid crystal molecules It can be seen that has a stable pretilt angle and is stably oriented.
Therefore, it can be seen that the alignment film of the present invention can impart the above characteristics to the liquid crystal display element.

<Test Example 2: Test of liquid crystal display elements of Examples 22 to 23>
About the liquid crystal display element of Examples 22-23, it measured and observed similarly to the liquid crystal display element of Example 17, and also measured the ion density. The results are shown in Table 8 below.

As shown in Table 8, it can be seen that the liquid crystal display element of Example 23 has a reduced ion density in the liquid crystal as compared with the liquid crystal display element of Example 22. On the other hand, it can be seen that phenomena such as an increase in residual DC and a decrease in VHR are not observed, and the pretilt angle and the stability of the alignment are not impaired.
Therefore, the liquid crystal alignment film of the present invention having a crown ether moiety (cyclic amino group represented by the above general formula (3)) can be used without deteriorating the characteristics (alignment characteristics, electrical characteristics, etc.) of the liquid crystal display element. It can be seen that the ions therein can be removed.

A liquid crystal display element using an alignment film made of a phenylenediamine derivative represented by the general formula (1) of the present invention has a high VHR and a low image sticking. Further, a stable pretilt angle can be given to the liquid crystal. Furthermore, when the alignment film of a liquid crystal display element is formed using the phenylenediamine (1) of the present invention, light leakage due to alignment failure can be suppressed.
Moreover, since the phenylenediamine (1) of the present invention can be produced at a low cost by a short synthesis route, a high-performance liquid crystal display element can be provided at a lower cost.
In particular, when phenylenediamine ( 1a ) having a long side chain is used, the pretilt angle can be made nearly vertical, which is important for VA liquid crystal display device applications. On the other hand, in particular the use of phenylenediamine (1b) having a crown ether ring, it is possible to reduce the ion density in the liquid crystal.

Claims (14)

Phenylenediamine represented by the following general formula (1a).

(In General Formula (1a), R ¹ is hydrogen or methyl, and N-Cycle is a group represented by the following General Formula (2).)

(In general formula (2),
R ² is hydrogen or a linear or branched alkyl having 1 to 20 carbon atoms, provided that in the alkyl, any —CH ₂ — is —CF ₂ —, —O—, or —C (═O). - it may be substituted with, but, -CH 2 that is continuous _- none of -O-, or -C (= O) - not be substituted with,
A ¹ , A ² , and A ³ are each independently a single bond, 1,4-cyclohexylene, 1,4-phenylene, or 1,4-bicyclo [2,2,2] octanylene, provided that In the 1,4-phenylene, 1 to 2 hydrogens on the benzene ring may be substituted with methyl, methoxy, or fluorine,
B ^{1, B 2,} and ^{B 3} are each independently a single bond, an alkylene of 1 to 4 carbon atoms, -O -, - OC (= O) -, - C (= O) O -, - NR 3 C (= O)-, or -C (= O
) N (—R ³ ) — provided that in the alkylene, any —CH ₂ — may be substituted with —CF ₂ —, —O—, or —C (═O) —. , None of the successive —CH ₂ — is substituted with —O— or C (═O) —
R ³ is hydrogen or alkyl having 1 to 10 carbons. ) In Formula (1a), an amino group (-NH ₂₎ is located in the 3,5-position relative to the amide group, phenylene diamine according to claim 1. In Formula (1a), an amino group (-NH ₂₎ is located in the 2,5-position relative to the amide group, phenylene diamine according to claim 1. In the general formula (2),
R ² is hydrogen or a linear or branched alkyl having 1 to 20 carbon atoms,
A ¹ , A ² , and A ³ are each independently a single bond, 1,4-cyclohexylene, 1,4-phenylene,
The phenylenediamine according to claim ¹ , wherein B ¹ , B ² , and B ³ are each independently a single bond and a linear alkylene having 1 to 4 carbon atoms. In the general formula (2),
R ² is a linear or branched alkyl having 1 to 12 carbon atoms,
A ¹ , A ² and A ³ are each independently 1,4-cyclohexylene or a single bond, and at least one is a single bond,
^2. The phenylenediamine according to claim ¹ , wherein B ¹ , B ² and B ³ are each independently ethylene or a single bond, and at least two are single bonds. Phenylenediamine represented by the following general formula (1b).

(In General Formula (1b), R ¹ is hydrogen or methyl, and N-Cycle is a cyclic amino group represented by the following structural formula (No. 155) to structural formula (No. 163) .)

  A polyamic acid or a polyimide, which is a reaction product of the phenylenediamine according to any one of claims 1 to 6 and tetracarboxylic dianhydride.   A polyamide which is a reaction product of the phenylenediamine according to any one of claims 1 to 6 and a dicarboxylic acid or a derivative thereof. A reaction product of the phenylenediamine according to any one of claims 1 to 6, a tetracarboxylic dianhydride and a dicarboxylic acid or a derivative thereof, or the phenylene according to any one of claims 1 to 6. Polyamideimide which is a reaction product of diamine and tricarboxylic acid or its derivative.   A varnish containing the polyamic acid or polyimide according to claim 7.   A varnish containing the polyamide according to claim 8.   A varnish containing the polyamideimide according to claim 9.   The alignment film formed using the varnish as described in any one of Claims 10-12.   A liquid crystal display element comprising the alignment film according to claim 13.