JP3212162B2 - Diaminobenzene derivative, polyimide and liquid crystal alignment film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel diaminobenzene derivative and a polyimide synthesized using the compound as one of raw materials. The present invention relates to a diamine having a long-chain alkyl group which is easy to produce and useful, and a polyimide having a long-chain alkyl group in a side chain and having improved surface properties, which is synthesized using the compound as one of the raw materials. The polyimide having the modified surface characteristics of the present invention is particularly useful for use as an alignment film of a liquid crystal display device.

[0002]

2. Description of the Related Art Hitherto, polyimide has been widely used as a protective material and an insulating material in the electric and electronic fields due to its high mechanical strength, heat resistance and solvent resistance. However, the development of the electric and electronic fields in recent years has been remarkable, and correspondingly, materials used have been required to have increasingly higher characteristics.

[0003] For example, a wholly aromatic polyimide conventionally known as a polyimide is excellent in mechanical strength and heat resistance, but has a drawback that the molecular structure itself is high in polarity and consequently poor in moisture absorption stability. When it is used as a protective material or an insulating material for electric / electronic devices, it has been a serious problem. Further, in the use of an alignment film for a liquid crystal display device, polyimide has been exclusively used until now because of the uniformity and durability of the coating film surface. However, as the density and performance of display elements have been increased, the surface characteristics of polyimide coating films have been particularly emphasized, and it has become necessary to provide new characteristics not available in conventional polyimides. Therefore, this point will be described in detail below.

A liquid crystal display element is a display element utilizing electro-optical change of liquid crystal, and is noted for its characteristics such as small size and light weight and low power consumption, and has recently been used as a display device for various displays. Has achieved remarkable development. Above all, using nematic liquid crystal having positive dielectric anisotropy, liquid crystal molecules are arranged parallel to the substrate at each interface of a pair of opposing electrode substrates, and the orientation directions of the liquid crystal molecules are orthogonal to each other. A twisted nematic (TN type) field effect type liquid crystal display element combining both substrates is a typical example thereof.

In such a TN type liquid crystal display device, the major axis direction of the liquid crystal molecules is aligned uniformly and parallel to the substrate surface, and the liquid crystal molecules are tilted with respect to the substrate at a predetermined tilt alignment angle (hereinafter, referred to as "the liquid crystal molecule"). It is important that the liquid crystal molecules are oriented with a tilt angle). As typical methods for aligning liquid crystal molecules in this manner, two methods have been conventionally known.

The first method is a method in which an inorganic material such as silicon oxide is vapor-deposited on a substrate to form an inorganic film on the substrate, and liquid crystal molecules are aligned in the vapor deposition direction.
In this method, a stable orientation having a certain tilt angle can be obtained, but it is not industrially efficient. The second method is a method in which an organic film is provided on the surface of a substrate, the surface is rubbed in a certain direction with a cloth such as cotton, nylon, or polyester, and liquid crystal molecules are aligned in the rubbing direction. In this method, a stable orientation can be obtained relatively easily, and therefore, this method is exclusively used industrially. As an organic film,
Examples thereof include polyvinyl alcohol, polyoxyethylene, polyamide, and polyimide. Of these, polyimide is most commonly used in terms of chemical stability, thermal stability, and the like. However, the tilt angle obtained by rubbing polyimide is usually about 1 to 3 °, and it has been difficult to obtain a higher tilt angle.

[0007]

In order to improve the moisture absorption stability of polyimides, polyimides having various chemical structures have been synthesized in recent years. For example, JP-A-61-83228
In Japanese Patent Application Laid-Open No. 61-118424, a polyimide / siloxane block copolymer is used as one of the raw materials for polyimide, using a diamine having an amino group at the end of polysiloxane to give the polyimide water repellency. Attempts have been made. In this case, as the siloxane content increases, the water repellency of the polyimide increases, but there is a problem that the ability to form a coating film decreases. Also, JP-A-2-49
No. 029, JP-A-2-60933 and the like use a fluorine-containing diamine or acid anhydride as one of the raw materials of polyimide, introduce a large amount of water-repellent fluorine into the polyimide molecular skeleton, Attempts to impart water repellency have been proposed. However, synthesis of such a fluorine-containing diamine or acid anhydride is not easy, and it is not a method that can be industrially produced, and it has been desired to develop a raw material that makes polyimide more water-repellent. .

In the field of liquid crystal alignment films, a method of rubbing an organic film such as polyimide has been proposed.
It has been difficult to stably obtain a high tilt angle. As a means for solving this problem, Japanese Patent Application No. 62-142099 proposes a liquid crystal alignment treatment agent comprising a reaction product of a long-chain alkylamine and a polyimide precursor. In this case, it was shown that the introduction of the long-chain alkyl group increased the tilt angle, but the amount of introduction was limited, so that the obtained tilt angle was limited. Japanese Patent Application Laid-Open Nos. 1-262527 and 1-262528 propose a liquid crystal aligning agent comprising a mixture of a long-chain alkyl compound and a polyimide precursor. In this case, the amount of the long-chain alkyl group introduced is not limited, and the tilt angle can be controlled in a wide range by the amount introduced. However, in the case of such a mixture, there has been a problem that the density of the alkyl group on the polyimide surface changes depending on the coating film thickness, and the tilt angle changes depending on the film thickness.

On the other hand, JP-A-64-25126 proposes a liquid crystal aligning agent comprising polyimide using a diamine having an alkyl group as a raw material. Thus, the change in the tilt angle due to the coating film thickness can be suppressed, but the density of the alkyl group per diamine is low, so that the obtained tilt angle is limited. Also, JP-A-4-733
No. 3 proposes a polyimide using a diamine having a chain alkyl group as a raw material. However, the synthesis of these diamines is not easy, and when a polyimide is polymerized using these as a raw material, a sufficient high molecular weight product cannot be obtained, which is also a problem in the properties as an alignment film. As described above, it has been desired to develop an industrially useful alignment agent that can control the tilt angle in a wide range by rubbing polyimide and that does not change the tilt angle depending on the coating film thickness.

[0010]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, completed the present invention. That is, the present invention provides: 1) a general formula [1]

[0011]

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(Wherein n represents an integer of 7 or more and 21 or less) 2) Diamino of the above 1) wherein n in the general formula [1] is an integer of 11 or more and 21 or less Benzene derivative; 3) reacting a diamine containing at least 1 mol% or more of a diaminobenzene derivative represented by the general formula [1] with tetracarboxylic acid and a derivative thereof to obtain a reduced viscosity of 0.
A general formula [2] comprising a polyimide precursor of 0.5 to 5.0 dl / g (concentration: 0.5 g / dl in N-methylpyrrolidone at a temperature of 30 ° C.) and ring-closing this.

[0013]

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(Wherein A is a tetravalent organic group constituting a tetracarboxylic acid, and n is an integer of 7 or more and 21 or less) A polyimide containing at least 1 mol% or more of a repeating unit represented by the formula: The polyimide of the above 3), which contains at least 5 mol% or more of the diaminobenzene derivative represented by the general formula [1]. 5) The tetracarboxylic acid and its derivative are an alicyclic tetracarboxylic acid and its derivative. 6) The polyimide according to 3) above, wherein the tetracarboxylic acid and its derivative are 1,2,3,4-cyclobutanetetracarboxylic dianhydride. And 7) a liquid crystal alignment film using the polyimide described in 3) above.

The diaminobenzene derivative of the present invention can be easily synthesized. By synthesizing the polyimide using this as one of the raw materials, a high molecular weight polyimide having a linear alkyl group in the side chain can be easily obtained. And surface properties of polyimide such as water repellency. In particular, in the case of an alignment film application of a liquid crystal display element, the distribution density of the alkyl group on the polyimide surface can be arbitrarily adjusted by adjusting the molar fraction of the diaminobenzene derivative,
The tilt angle can be controlled over a wide range, the tilt angle is less dependent on the film thickness, and stable orientation can be obtained.

The diaminobenzene derivative represented by the general formula [1] of the present invention can be synthesized, for example, by the following production method. That is, the general formula [3]

[0017]

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(Wherein X represents a halogen atom), and dinitrobenzyl halide represented by the general formula [4]

[0019]

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(Wherein, n represents an integer of 7 or more and 21 or less) is reacted with a linear alkyl alcohol represented by the following general formula [5]:

[0021]

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Wherein, in the formula, n represents an integer of 7 or more and 21 or less, a dinitrobenzene derivative represented by
Further, the desired diaminobenzene derivative represented by the general formula [1] is synthesized by reducing the nitro group in the compound represented by the general formula [5] by a conventional method and converting it to an amino group. Can be.

Examples of the dinitrobenzyl halide represented by the general formula [3] include 3,5-dinitrochlorobenzyl, 3,5-dinitrobromobenzyl, and 3,5-dinitroiodobenzyl. . Examples of the linear alkyl alcohol represented by the general formula [4] include 1-octanol, 1-nonanol, 1-decanol, and 1-octanol.
Undecaneol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1 -Hen eicosanol, 1-dodecosanol and the like.

The base used in the reaction of the dinitrobenzyl halide represented by the general formula [3] with the linear alkyl alcohol represented by the general formula [4] includes, for example, sodium hydroxide, potassium hydroxide, Inorganic salts such as calcium hydroxide, sodium carbonate, potassium carbonate and sodium hydride are preferably used. In this reaction, by allowing a phase transfer catalyst such as tetrabutylammonium hydrogen sulfate, tetrabutylammonium bromide, or tetrabutylammonium iodide to coexist, the reaction can also proceed more smoothly.

As a solvent used in the present reaction, an organic solvent such as tetrahydrofuran, hexane, cyclohexane, benzene, and toluene can be used, and a polar solvent such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, and N-methylpyrrolidone can be used. Is preferred. The reaction temperature of this reaction can be selected from any temperature of -30 to 150 ° C.

The reduction reaction from the dinitrobenzene derivative represented by the general formula [5] to the diaminobenzene derivative represented by the general formula [1] of the present invention is carried out by using a reducing agent such as diborane or lithium borohydride. The reaction proceeds easily by the reaction, and the desired product can be obtained by reacting with a hydrosilane compound such as trichlorosilane, tripropylsilane or triethylsilane in the presence of zinc chloride. Furthermore, catalytic reduction using a metal such as nickel, platinum, palladium, and rhodium as a catalyst under a hydrogen gas atmosphere can also be performed.

The solvent used in this reaction may be any solvent that does not participate in the reaction, and examples thereof include alcohol, tetrahydrofuran, dimethoxyethane, dioxane, benzene, and toluene. The reaction temperature of this reaction can be in the range of -100 to 150 ° C, preferably -50 to 100 ° C.

The diaminobenzene derivative of the present invention represented by the above-mentioned general formula [1] obtained by the above-mentioned production method can be used as a tetracarboxylic acid, a tetracarboxylic dihalide, a tetracarboxylic dianhydride or the like. By performing polycondensation with an acid and a derivative thereof, a polyimide having a linear alkyl group in a side chain can be synthesized.

The method for obtaining the polyimide of the present invention is not particularly limited. Specifically, it can be obtained by reacting and polymerizing a tetracarboxylic acid or a derivative thereof with a primary diamine to form a polyimide precursor, and then performing ring-closing imidization. The tetracarboxylic acid and its derivative used for obtaining the polyimide of the present invention are not particularly limited.

Specific examples thereof include pyromellitic acid,
2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-anthracenetetracarboxylic Acid, 1,2,
5,6-anthracenetetracarboxylic acid, 3,3 ', 4,4'-biphenyltetracarboxylic acid, 2,3,3', 4-biphenyltetracarboxylic acid, bis (3,4-dicarboxyphenyl) ether, 3,3 ', 4,4'-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2,2-bis (3,4-di Carboxyphenyl) propane, 1,1,1,3,3,3-hexafluoro
-2,2-bis (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,
Aromatic tetracarboxylic acids such as 4,5-pyridinetetracarboxylic acid and 2,6-bis (3,4-dicarboxyphenyl) pyridine and dianhydrides thereof, and dicarboxylic acid diacid halides thereof; , 3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,
5-cyclohexanetetracarboxylic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-
Alicyclic tetracarboxylic acids such as tetrahydro-1-naphthalene succinic acid and their dianhydrides, dicarboxylic acid diacid halides thereof, and aliphatic tetracarboxylic acids such as 1,2,3,4-butanetetracarboxylic acid And their dianhydrides and their dicarboxylic acid diacid halides.

In particular, for use as an alignment film, alicyclic tetracarboxylic acids, dianhydrides thereof, and dicarboxylic acid diacid halides thereof are preferable from the viewpoint of the transparency of the coating film. , 4-Cyclobutanetetracarboxylic dianhydride is preferred. Further, one or more of these tetracarboxylic acids and derivatives thereof may be used in combination.

The present invention relates to a tetracarboxylic acid and a derivative thereof, a diaminobenzene derivative represented by the general formula [1] (hereinafter abbreviated as alkyldiamine) and another general diamine (hereinafter abbreviated as general diamine). By copolymerization, a polyimide having a linear alkyl group having 8 or more carbon atoms in the side chain is obtained, and the surface characteristics of the polyimide such as water repellency are modified by adjusting the alkyl group density of the side chain. It is intended to stably control the increased tilt angle of the liquid crystal in a wide range. Therefore, the diamine used to obtain the polyimide of the present invention contains an alkyl diamine as an essential component.

The alkyl group in the alkyl diamine is a linear alkyl group having 8 or more carbon atoms, and preferably has 1 carbon atom.
It is a straight-chain alkyl group having 2 or more, and is substantially a straight-chain alkyl group having 12 to 22 carbon atoms from the viewpoint of ease of synthesis. The greater the number of carbon atoms, the greater the effect of increasing the water repellency of the polyimide, and the greater the effect of increasing the tilt angle.

The general diamine other than the alkyl diamine is
It is a primary diamine generally used for polyimide synthesis, and is not particularly limited. If specific examples are given, p-phenylenediamine, m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene,
4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, diaminodiphenylmethane, diaminodiphenylether, 2,2-diaminodiphenylpropane, Screw (3,
5-diethyl-4-aminophenyl) methane, diaminodiphenylsulfone, diaminobenzophenone, diaminonaphthalene, 1,4-bis (4-aminophenoxy) benzene,
1,4-bis (4-aminophenyl) benzene, 9,10-bis (4-aminophenyl) anthracene, 1,3-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) ) Diphenyl sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) A) Alicyclic diamines such as aromatic diamines such as hexafluoropropane, bis (4-aminocyclohexyl) methane and bis (4-amino-3-methylcyclohexyl) methane, and fats such as tetramethylenediamine and hexamethylenediamine Group diamines, and

[0035]

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(Wherein, n represents an integer of 1 to 10). Further, one or more of these diamines can be used in combination. When polymerizing the polyimide of the present invention, the surface properties of polyimide such as water repellency can be modified by adjusting the ratio of the number of moles of alkyldiamine to the total number of moles of diamine used, and further used as a liquid crystal alignment film In this case, the tilt angle of the liquid crystal can be stably controlled over a wide range from 1 ° to 90 °. In this case, the ratio of the alkyl diamine is 1 mol% or more and 100 mol% or less, preferably 5 mol% or less.
It is not less than 100 mol% and not more than 100 mol%.

After a tetracarboxylic acid and its derivative are reacted with an alkyl diamine and a general diamine to produce a polyimide precursor, which is then subjected to ring-closing imidization, the tetracarboxylic acid and its derivative used in this case are tetracarboxylic acid. It is common to use dianhydrides. The ratio of the number of moles of tetracarboxylic dianhydride to the total number of moles of alkyl diamine and general diamine is preferably 0.8 to 1.2. As in the ordinary polycondensation reaction, the degree of polymerization of the produced polymer increases as the molar ratio approaches 1.

When the degree of polymerization is too small, the strength of the polyimide film when used as an alignment film is insufficient, and the alignment of the liquid crystal becomes unstable.

On the other hand, if the degree of polymerization is too large, the workability during the formation of the polyimide film may be deteriorated. Therefore, the degree of polymerization of the product in this reaction is 0.05 to 5.0 dl / g (at a temperature of 30) in terms of reduced viscosity of the polyimide (resin) precursor solution.
The concentration is preferably 0.5 g / dl in N-methylpyrrolidone at ° C.

The method of reacting and polymerizing the tetracarboxylic dianhydride with the primary diamine is not particularly limited, and generally, N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, etc. A method of dissolving a primary diamine in an organic polar solvent of the above, adding a tetracarboxylic dianhydride to the solution, reacting the solution, and synthesizing a polyimide precursor, followed by dehydration ring-closing imidization.

The reaction temperature when reacting tetracarboxylic dianhydride with a primary diamine to obtain a polyimide precursor is as follows:
Any temperature between 20 and 150 ° C, preferably between -5 and 100 ° C can be chosen.

Further, this polyimide precursor was added to
A polyimide can be obtained by heat dehydration at a temperature of ° C. or by chemically imidizing using a commonly used imidization catalyst such as triethylamine / acetic anhydride. The polyimide of the present invention is an insulating film of an electric / electronic element,
When used as a protective film and further as an alignment film of a liquid crystal display element, it is necessary to form a polyimide film having a uniform thickness on the substrate. In order to form the polyimide coating film, usually, a polyimide precursor solution is applied as it is to a substrate, and is heated and imidized on the substrate to form a polyimide coating film. As the polyimide precursor solution used at this time, the above-mentioned polymerization solution may be used as it is, or the produced polyimide precursor is poured into a poor solvent such as a large excess of water or methanol, and the precipitate is recovered. It may be dissolved before use. The solvent for diluting the polyimide precursor solution and / or the solvent for re-dissolving the precipitated and recovered polyimide precursor is not particularly limited as long as it can dissolve the polyimide precursor.

Specific examples of these solvents include N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and the like. These may be used alone or as a mixture. Further, even if the solvent alone cannot provide a uniform solution, the solvent may be added and used within a range where a uniform solution can be obtained.

The temperature for imidization on the substrate by heating is 1
Any temperature of 00 to 400 ° C can be adopted, but especially 150 to 350
C. is preferred.

On the other hand, when the polyimide of the present invention is dissolved in a solvent, a polyimide precursor obtained by reacting tetracarboxylic dianhydride with a primary diamine may be imidized in a solution to form a polyimide solution. it can. When a polyimide precursor is converted into polyimide in a solution, a method of dehydrating and cyclizing by heating is usually employed. The ring closure temperature by this heat dehydration is from 100 to 350 ° C., preferably
Any temperature between 120 and 250 ° C can be selected.

As another method for converting the polyimide precursor into polyimide, the ring can be chemically closed using a known dehydration ring-closing catalyst.

The polyimide solution thus obtained can be used as it is, or can be used by precipitating and isolating in a poor solvent such as methanol or ethanol and then re-dissolving in a suitable solvent. The solvent to be redissolved
There is no particular limitation as long as it dissolves the obtained polyimide, but examples thereof include 2-pyrrolidone, N-methylpyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone,
N, N-dimethylacetamide, N, N-dimethylformamide, γ-butyrolactone and the like can be mentioned.

In addition, a solvent which does not dissolve the polyimide alone may be added to the above solvent as long as the solubility is not impaired. Examples thereof include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol and the like.

It is of course preferable to add an additive such as a coupling agent to the obtained polyimide solution for the purpose of further improving the adhesion between the polyimide film and the substrate. This solution is applied on a substrate, and a solvent is evaporated to form a polyimide film on the substrate. The temperature at this time is sufficient if the solvent evaporates, usually from 80.
150 ° C is sufficient.

[0050]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

1. Example 1 Synthesis of Dinitrobenzene Derivative Example 1 30.9 g (0.166 mol) of 1-dodecanol and sodium hydride
7.31 g (0.183 ol) was reacted in 300 ml of tetrahydrofuran under reflux for 6 hours. To this solution, 30.1 g (0.139 mol) of 3,5-dinitrobenzyl chloride was added
After the solution dissolved in l was added dropwise at -20 ° C, the mixture was reacted at room temperature for 2 hours. After distilling off tetrahydrofuran, the residue was washed with water / chloroform to obtain a light brown solid. This solid was dissolved in chloroform and purified using a silica gel column.
15.8 g (yield 31%) of a dinitrobenzene derivative represented by the following structural formula [6] was obtained as a white powder. The product was confirmed by IR and NMR.

IR spectrum (cm ^-1 ): 3110, 2918, 2840,
1552 (characteristic absorption by nitro group), 1458,1330 (characteristic absorption by nitro group), 1124 (characteristic absorption by ether bond), 910, 872,799,710 ¹ H-NMR spectrum δ (CDCl ₃ ); 0.96 (3H, t, CH)
₃ ), 1.08-1.66 (20H, m, -CH _2- ), 3.60 (2H, t, -O-CH _2- ),
4.71 (2H, bs, -CH ₂ -O-), 8.58 (2H, bs, β-H), 9.04 (1H, bs,
α-H)

[0053]

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Next, the obtained dinitrobenzene derivative 10
g was dissolved in 100 ml of dioxane, 2 g of 5% -palladium carbon was added, and a reduction reaction was performed at room temperature for 12 hours while passing hydrogen. After filtering the catalyst, 200 ml of water was added, and the resulting precipitate was recrystallized from n-hexane. As a result, 6.0 g of a diaminobenzene derivative represented by the following structural formula [7] (72% yield)
) Was obtained as a light brown powder. Confirmation of the product
It was performed from IR and NMR.

IR spectrum (cm-1): 3398, 3170 (characteristic absorption by amino group), 2915, 2850, 1588, 1450, 136
5 (characteristic absorption by diaminophenyl group), 1195, 1110
(Characteristic absorption by ether bond), 1100, 809, 715 ¹ H-NMR spectrum δ (CDCl ₃ ); 0.90 (3H, t, CH
₃ ), 1.06-1.67 (20H, m, -CH _2- ), 3.44 (6H, m, -O-CH _2- ,
NH ₂ ), 4.29 (2H, s, -CH ₂ -O-), 6.00 (2H, bs, β-H), 6.
15 (1H, bs, α-H)

[0056]

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Example 2 The same reaction as in Example 1 was carried out except that 40.2 g (0.166 mol) of 1-hexadecanol was used instead of 1-dodecanol.
8.2 g (31% yield) was obtained as a light brown powder. The product was confirmed by IR and NMR.

IR spectrum (cm ^-1 ): 3114, 2910, 284
7, 1539 (characteristic absorption by nitro group), 1469, 1349 (characteristic absorption by nitro group), 1131 (characteristic absorption by ether bond), 920, 878, 808, 730 ¹ H-NMR spectrum δ (CDCl ₃ ); 0.97 (3H, t, C
H ₃ ), 1.09-1.69 (28H, m, -CH _2- ), 3.63 (2H, t, -O-CH _2- ),
4.72 (2H, bs, -CH ₂ -O-), 8.58 (2H, bs, β-H), 9.00 (1
H, bs, α-H)

[0059]

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Next, the obtained dinitrobenzene derivative 10
g was dissolved in 100 ml of dioxane and reacted in the same manner as in Example 1.

[9] Diaminobenzene derivative
6.0 g (yield 70%) was obtained as a white powder. The product was confirmed by IR and NMR. IR spectrum (cm-1): 3409, 3110 (characteristic absorption by amino group), 2917, 2847, 1602, 1469, 1370 (characteristic absorption by diaminophenyl group), 1195, 1110 (characteristic absorption by ether bond), 1103, 815, 723 ¹ H-NMR spectrum δ (CDCl ₃ ); 0.89 (3H, t, CH
3), 1.07-1.67 (28H, m, -CH _2- ), 3.42 (6H, m, -O-CH _2- ,
NH ₂ ), 4.30 (2H, s, -CH ₂ -O-), 5.97 (2H, bs, β-H), 6.1
3 (1H, bs, α-H)

[0061]

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Example 3 The same reaction as in Example 1 was carried out except that 44.9 g (0.166 mol) of 1-octadecanol was used in place of 1-dodecanol, and a dinitrobenzene derivative represented by the following structural formula [10] was obtained.
13.8 g (22% yield) was obtained as a light brown powder. The product was confirmed by IR and NMR.

IR spectrum (cm ^-1 ): 3115, 2912, 285
0, 1539 (characteristic absorption by nitro group), 1469, 1350 (characteristic absorption by nitro group), 1128 (characteristic absorption by ether bond), 915, 870, 803, 740 ¹ H-NMR spectrum δ (CDCl ₃ ); 0.98 (3H, t, CH ₃ ),
1.10-1.72 (32H, m, -CH _2- ), 3.60 (2H, t, -O-CH _2- ),
4.71 (2H, bs, -CH ₂ -O-), 8.58 (2H, bs, β-H), 9.02 (1
H, bs, α-H)

[0064]

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Next, the obtained dinitrobenzene derivative 10
g was dissolved in 100 ml of dioxane and reacted in the same manner as in Example 1 to obtain a dinitrobenzene derivative represented by the following structural formula [11].
5.4 g (62% yield) were obtained as a white powder. The product was confirmed by IR and NMR. IR spectrum (cm ^-1 ); 3409, 3111 (characteristic absorption by amino group), 2920, 2844, 1600, 1491, 1400 (characteristic absorption by diaminophenyl group), 1205, 1110 (characteristic absorption by ether bond), 1120, 817, 710 ¹ H-NMR spectrum δ (CDCl ₃ ); 0.88 (3H, t, CH ₃ ),
1.09-1.69 (32H, m, -CH _2- ), 3.48 (6H, m, -O-CH _2- , N
H ₂ ), 4.32 (2H, s, -CH ₂ -O-), 5.95 (2H, bs, β-H), 6.1
2 (1H, bs, α-H)

[0066]

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Next, polyimide was polymerized using the diaminobenzene derivatives obtained in Examples 1 to 3.

2. Production of Polyamic Acid Example 4 30.7 g (0.1 mol) of the diaminobenzene derivative of the structural formula [7] obtained in Example 1, 1,2,3,4-cyclobutanetetracarboxylic dianhydride (hereinafter referred to as CBDA) 19.6 g)
(0.1 mol) was dissolved in 285 g of N-methylpyrrolidone (hereinafter abbreviated as NMP) and stirred at 20 ° C. for 4 hours to carry out a polycondensation reaction to prepare a polyamic acid intermediate solution.

The reduced viscosity of the obtained polymer was 0.83 dl /
g (concentration: 0.5 g / dl, in NMP at 30 ° C.). This solution was coated on a glass substrate and heat-treated at 250 ° C for 1 hour.
A uniform polyimide coating was formed. I of the obtained coating film
An R measurement was performed to confirm that the polyimide contained a linear alkyl group.

Example 5 In Example 4, the structural formula obtained in Example 2 as a diaminobenzene derivative was obtained.

A polyamic acid intermediate solution was prepared in the same manner except that 36.3 g (0.1 mol) of the diaminobenzene derivative of [9] was used and NMP was changed to 317 g. The reduced viscosity of the obtained polymer is 0.66 dl / g (concentration
0.5 g / dl, 30 ° C. in NMP).

This solution was coated on a glass substrate and heated at 250 ° C.
/ 1 hour heat treatment to form a uniform polyimide coating. IR measurement of the obtained coating film confirmed that it was a polyimide containing a linear alkyl group.

Example 6 Example 4 was repeated except that the diaminobenzene derivative used was 39.1 g (0.1 mol) of the diaminobenzene derivative of the structural formula [11] obtained in Example 3 and the NMP was 333 g. Thus, a polyamic acid intermediate solution was prepared. The reduced viscosity of the obtained polymer is 0.56 dl / g (concentration
0.5 g / dl, 30 ° C. in NMP).

This solution was coated on a glass substrate and heated at 250 ° C.
/ 1 hour heat treatment to form a uniform polyimide coating. IR measurement of the obtained coating film confirmed that it was a polyimide containing a linear alkyl group.

Example 7 In Example 4, instead of 30.7 g (0.1 mol) of the diaminobenzene derivative of the structural formula [7], 6.13 g (0.02 mol) of the diaminobenzene derivative of the structural formula [7], 2,2-bis [Four-
(4-aminophenoxy) phenyl] propane (hereinafter referred to as B
32.8 g (0.08 mol) of NMP
A polyamic acid intermediate solution was prepared in the same manner except that the amount was 2 g. The reduced viscosity of the obtained polymer is 2.07 d
l / g (concentration: 0.5 g / dl, in NMP at 30 ° C.).

This solution was coated on a glass substrate and heated at 250 ° C.
/ 1 hour heat treatment to form a uniform polyimide coating. IR measurement of the obtained coating film confirmed that it was a polyimide containing a linear alkyl group.

Example 8 In Example 7, 21.8 g (0.1 mol) of pyromellitic dianhydride (hereinafter abbreviated as PMDA) was used instead of CBDA.
And a polyamic acid intermediate solution was prepared in the same manner except that NMP was changed to 385 g. The reduced viscosity of the obtained polymer was 2.30 dl / g (concentration: 0.5 g / dl, in NMP,
30 ° C).

This solution was coated on a glass substrate and heated at 250 ° C.
/ 1 hour heat treatment to form a uniform polyimide coating. IR measurement of the obtained coating film confirmed that it was a polyimide containing a linear alkyl group.

Comparative Example 1 In Example 7, 41.0 g (0.1 mol) of BAPB and NMP 3 were used without using the diaminobenzene derivative of the structural formula [7].
A polyamic acid intermediate solution was prepared in the same manner except that 43 g was used. The reduced viscosity of the obtained polymer is 1.20.
dl / g (concentration: 0.5 g / dl, in NMP at 30 ° C.).

Comparative Example 2 In Example 8, 41.0 g (0.1 mol) of BAPB and NMP35 were used without using the diaminobenzene derivative of the structural formula [7].
A polyamic acid intermediate solution was prepared in the same manner except that 6 g was used. The reduced viscosity of the obtained polymer is 1.20.
dl / g (concentration: 0.5 g / dl, in NMP at 30 ° C.). Reference Example Next, the polyamic acid intermediate solution obtained in Examples 4 to 8 and Comparative Examples 1 and 2 was coated on a glass substrate,
Heat treatment was carried out for 1 hour to form a polyimide coating film, and the water repellency of the polyimide surface and the tilt angle of the liquid crystal when a liquid crystal alignment film was formed were measured by the following methods.

Evaluation of water repellency: The polyamic acid intermediate solution was diluted with NMP to prepare a solution having a resin concentration of 6%, and spin-coated on a glass substrate at 3500 rpm, and at 180 ° C. for 10 minutes, 180 ° C.
For 1 hour to form a uniform polyimide coating film, and the contact angle of water on the coating film was measured. Evaluation of tilt angle: The polyamic acid intermediate solution was diluted with NMP to prepare a solution having a resin concentration of 6%, and spin-coated on a glass substrate with a transparent electrode at 3500 rpm, and at 180 ° C. for 10 minutes, 180 ° C.
For 1 hour to form a uniform polyimide coating.

After this coating film was rubbed with a cloth, the rubbing directions were set parallel to each other with a 50 μm spacer interposed therebetween, and a liquid crystal (ZLI-2293 manufactured by Merck) was injected to prepare a cell with homogeneous alignment. The tilt angle of this cell was measured by the crystal rotation method. When the tilt angle was close to 90 °, the cell was observed with a deflection microscope, and an isogyre near the center of the visual field was observed, confirming that the tilt angle was approximately 90 °. [Table 1] Test results Diaminobenzene derivative Polyimide Heat treatment Contact angle Tilt angle (Example) (Example) (° C) (°) (°) 14 180 82 90 25 5 180 94 90 90 6 6 180 98 90 17 17 180 75 4.6 18 180 77 77 4.4 ───────────────────────────────-Comparative example 1 180 65 2. 1-Comparative Example 2 180 63 2.0

[0082]

The diaminobenzene derivative of the present invention is easy to synthesize. By synthesizing polyimide using this as one of the raw materials, it is possible to easily polymerize a high molecular weight polyimide and obtain a polyimide having water repellency and the like. Can be modified. Further, in the case of polyimide for an alignment film of a liquid crystal display element, the tilt angle can be controlled over a wide range by adjusting the molar fraction of the diaminobenzene derivative.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Eiichi Akiyama 96, Fujisawa, Fujisawa-shi, Kanagawa Prefecture (72) Inventor Yuriko Takamura 3552-3 Kamizuruma, Sagamihara-shi, Kanagawa Examiner Hiroki Amano (56) References -281631 (JP, A) JP-A-4-7333 (JP, A) JP-A-4-294327 (JP, A) JP-A-5-43687 (JP, A) JP-A-5-43688 (JP, A (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 73/00-73/26 C08L 79/00-79/08 C07C 217/76 CAPPLUS (STN) REGISTRY (STN)

Claims (7)

(57) [Claims] 1. A compound of the general formula [1] (Wherein, n represents an integer of 7 or more and 21 or less). 2. A compound of the general formula [1] 2. The diaminobenzene derivative according to claim 1, wherein n is an integer of 11 or more and 21 or less. 3. A compound of the general formula [1] (Wherein, n represents an integer of 7 or more and 21 or less). A diamine containing at least 1 mol% or more of a diaminobenzene derivative and a tetracarboxylic acid and a derivative thereof are reacted, and the reduced viscosity is 0.05 to 5.0 dl / g (Temperature 3
A polyimide precursor having a concentration of 0.5 g / dl in N-methylpyrrolidone at 0 ° C., which is obtained by ring-closing a polyimide precursor represented by the general formula [2]: (Wherein, A represents a tetravalent organic group constituting a tetracarboxylic acid, and n represents an integer of 7 or more and 21 or less) A polyimide containing at least 1 mol% or more of a repeating unit represented by the following formula: 4. A compound of the general formula [2] (Wherein, A represents a tetravalent organic group constituting a tetracarboxylic acid, and n represents an integer of 7 or more and 21 or less), which contains at least 5 mol% or more of a diaminobenzene derivative represented by the following formula: Item 3. The polyimide according to Item 3. 5. The polyimide according to claim 3, wherein the tetracarboxylic acid and its derivative are alicyclic tetracarboxylic acid and its derivative. 6. The method of claim 1, wherein the tetracarboxylic acid and its derivative are
4. The polyimide according to claim 3, which is 2,3,4-cyclobutanetetracarboxylic dianhydride. 7. A liquid crystal alignment film using the polyimide according to claim 3.