JP2561565B2 - Liquid crystal alignment agent - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal alignment treatment agent, and more specifically, a fluorine-containing diaminobenzene derivative having a perfluoroalkyl group, and / or
Excellent heat resistance and solvent resistance synthesized from siloxane-containing diaminobenzene derivative having siloxane chain.
Moreover, the present invention relates to a liquid crystal alignment treatment agent using a polyimide having a fluorine-containing group and / or a siloxane chain as a side chain having excellent surface characteristics and having liquid crystal molecules having an increased tilt alignment angle with respect to a substrate.

[0002]

2. Description of the Related Art Organic resin films such as polyimide resin films have hitherto been the most popular substrate treating agents for orienting nematic liquid crystal molecules substantially parallel to a transparent substrate such as a glass or plastic film having a transparent electrode. Commonly used. In this case, by rubbing the organic resin film formed on the substrate with a cloth in a certain direction, liquid crystal molecules are aligned in the rubbing direction, and at the same time, a liquid crystal tilt alignment angle of about 1 to 3 ° is usually formed with respect to the substrate surface. Is known to cause Further, as a method of largely orienting the liquid crystal molecules, a method of depositing an inorganic film such as silicon oxide on a substrate has been conventionally performed.

[0003]

With the conventional method of rubbing the organic resin film formed on the substrate, it is difficult to align the liquid crystal molecules to a large tilt, and the method of depositing the inorganic film on the substrate is also difficult. Is more complicated than the rubbing method,
It is not always an appropriate method in actual industrial production.

[0004]

As means for solving the above-mentioned problems, JP-A-62-142099 proposes a liquid crystal alignment treatment agent comprising a reaction product of a long-chain alkylamine and a polyimide resin precursor. . Also, JP-A 64-251
No. 26 proposes a liquid crystal alignment treatment agent composed of a polyimide obtained by using a diamine having an alkyl group as a raw material.

However, as in the present invention, a liquid crystal alignment treatment agent comprising a polyimide containing a fluorine-containing diaminobenzene derivative and / or a siloxane-containing diaminobenzene derivative and having a fluorine-containing group and / or a siloxane chain in a side chain is used as a liquid crystal alignment treatment agent. It is not known to give significantly higher tilted orientation angles of the molecule.

That is, the present invention is (In the formula, A ¹ is a tetravalent organic group forming a tetracarboxylic acid, A ² is a divalent organic group forming a diamine, B is a divalent organic group, and R ^{1 to} R ⁵ are the same or different. It is also preferably an alkyl group, a substituted alkyl group, a phenyl group or a substituted phenyl group, m is an integer of 1 or more, n is an integer of 1 to 6,
p is an integer of 1 to 12, provided that m, n, p, A ¹ ,
A ² , B, R ¹ and R ² may be different for each repeating unit. ) And the combination of these repeating units is a) general formulas [I], [II] and [III], b) general formulas [I] and [II], and c) general formulas [I] and [III]. ] D) General formula [II], e) General formula [III] or f) General formulas [II] and [III], and having a weight average molecular weight of 10,000 or more and a fluorine-containing group in the side chain And / or a liquid crystal alignment treatment agent made of a polyimide having a siloxane chain.

The liquid crystal alignment treatment agent of the present invention is used as a liquid crystal alignment treatment agent by applying it on a transparent substrate such as a glass or plastic film having a transparent electrode to form a polyimide resin film and then rubbing it. can do. Furthermore, by adjusting the mole fraction of the general formula [II] and / or the mole fraction of the general formula [III], the tilt alignment angle (hereinafter referred to as the tilt angle) of the liquid crystal can be adjusted.

The method for obtaining the polyimide used in the present invention is not particularly limited. Generally, the general formula [IV] (In the formula, A ¹ represents a tetravalent organic group constituting tetracarboxylic acid, and the four carbonyl groups bonded to A ¹ are directly bonded to different carbon atoms.) One or more compounds selected from an acid and its derivative and a general formula [V] H ₂ N—A ² —NH ₂ [V] (In the formula, A ² represents a divalent organic group constituting diamine. And a general formula [VI] (In the formula, n is an integer of 1 to 6 and p is an integer of 1 to 12.) and / or the general formula [VII]. (In the formula, B is a divalent organic group, R ^{1 to} R ⁵ may be the same or different, are an alkyl group, a substituted alkyl group, a phenyl group or a substituted phenyl group, and m is an integer of 1 or more, provided that , R ¹ and R ² may be optionally different for each repeating unit.), And a polyorganosiloxane having a diaminophenyl group at one end is polymerized.

Specific examples of the tetracarboxylic acid represented by the general formula [IV] and derivatives thereof include, for example, pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5, and 6-naphthalene tetracarboxylic acid, 1,4,5,8-naphthalene tetracarboxylic acid,
2,3,6,7-anthracene tetracarboxylic acid, 1,
2,5,6-anthracene tetracarboxylic acid, 3,
3 ', 4,4'-diphenyltetracarboxylic acid, bis (3,4-dicarboxyphenyl) ether, 3,
3 ', 4,4'-benzophenone tetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2,2-bis (3,4-dicarboxyphenyl) ) Propane 1,
1,1,3,3,3-hexafluoro-2,2-bis (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxy) Phenyl) diphenylsilane, 2,3,5,6-pyridinetetracarboxylic acid, 2,
Aromatic tetracarboxylic acids such as 6-bis (3,4-dicarboxyphenoxy) pyridine compounds and their dianhydrides, dicarboxylic acid diacid halides, cyclobutane tetracarboxylic acid, cyclopentane tetracarboxylic acid, cyclohexane tetra Alicyclic tetracarboxylic acids such as carboxylic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid, dianhydrides thereof, and dicarboxylic acid diacid halides thereof;
Examples include aliphatic tetracarboxylic acids such as butanetetracarboxylic acid, dianhydrides thereof, and dicarboxylic acid diacid halides thereof. The tetracarboxylic acid of the general formula [IV] and its derivative may be used alone or in combination of two or more.

Specific examples of the diamine compound represented by the above general formula [V] include, for example, m-diaminobenzene, p-diaminobenzene, 2,7-diaminonaphthalene, 2,6-diaminonaphthalene, 2 , 7-diaminoanthracene, 2,6-diaminoanthracene, 1,
8-diaminocentracene, 3,3'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 4,
4'-diaminobenzophenone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfide, 4,
4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2-bis (3-aminophenyl) propane, 1,3-bis (4-aminophenoxy) benzene,
1,4-bis (4-aminophenoxy) benzene, 4,
4'-di (4-aminophenoxy) diphenyl sulfone, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 1,1,1,3,3,3-hexafluoro-2,2 -Bis [4-aminophenyl] propane, 1,1,1,3,3,3-hexafluoro-2,2
An aromatic diamine such as -bis [4- (4-aminophenoxy) phenyl] propane, And the like. Other alicyclic diamines and aliphatic diamines may be used depending on the purpose. Further, one kind or a mixture of two or more kinds of these diamines can be used.

The fluorine-containing diaminobenzene derivative represented by the general formula [VI] is represented by the general formula [VIII] (Wherein X represents a halogen atom) and a dinitrobenzyl halide represented by the general formula [IX] (In the formula, n is an integer of 1 to 6, and p is an integer of 1 to 12.) By reacting with a fluorine-containing alcohol in a solvent in the presence of a base, a compound of the general formula [X] (In the formula, n is an integer of 1 to 6 and p is an integer of 1 to 12.) The dinitrobenzene derivative represented by the formula is first synthesized, and the dinitro group in the compound represented by the general formula [X] is usually added. The desired diaminobenzene derivative represented by the above general formula [VI] can be synthesized by reducing the compound to a diamino group by the method (1).

Examples of the dinitrobenzyl halide represented by the general formula (VIII) include 3,5-dinitrobenzyl chloride, 3,5-dinitrobenzyl bromide and 3,5.
-Dinitrobenzyl iodide, 2,4-dinitrobenzyl chloride, 2,4-dinitrobenzyl bromide, 2,
4-dinitrobenzyl iodide, 2,5-dinitrobenzyl chloride, 2,5-dinitrobenzyl bromide,
Examples thereof include 2,3-dinitrobenzyl chloride and 2,3-dinitrobenzyl bromide. Further, as the fluorine-containing alcohol represented by the general formula (VI), 2,2,2-trifluoroethanol, 2,2,2
3,3,3-pentafluoro-1-propanol, 3,
3,3-trifluoro-1-propanol, 1H, 1
H, 2H, 2H-pentafluoro-1-butanol,
3,3,3-trifluoro-1-butanol, 1H, 1
H-nonafluoro-1-pentanol, 1H, 1H, 2
H, 2H-heptafluoro-1-pentanol, 3,
3,3-trifluoro-1-pentanol, 1H, 1H
-Undecafluoro-1-hexanol, 1H, 1H,
2H, 2H-nonafluoro-1-hexanol, 3,
3,3-trifluoro-1-hexanol, 3,3,3
-Trifluoro-1-heptanol, 1H, 1H-pentadecafluoro-1-octanol, 1H, 1H, 2
H, 2H-tridecafluoro-1-octanol, 1
H, 1H-nonadecafluoro-1-decanol, 1H,
1H, 2H, 2H-heptadecafluoro-1-decanol, 1H, 1H-tricosafluoro-1-dodecanol, 1H, 1H, 2H, 2H-henicosafluoro-1
-Dodecanol, 1H, 1H-pentacosafluoro-1
-Tridecanol, 1H, 1H, 2H, 2H-pentacosafluoro-1-tetradecanol and the like can be exemplified.

Examples of the base used in the reaction between the dinitrobenzyl halide represented by the general formula [VIII] and the fluorine-containing alcohol represented by the general formula [IV] are, for example, sodium hydroxide, potassium hydroxide and water. Inorganic bases such as calcium oxide, sodium carbonate, potassium carbonate and sodium hydride are preferably used. In this reaction, the reaction can be allowed to proceed more smoothly by coexisting a phase transfer catalyst such as tetrabutylammonium hydrogen sulfate, tetrabutylammonium bromide or tetrabutylammonium iodide. This reaction preferably proceeds at a temperature near room temperature, and organic solvents such as tetrahydrofuran, hexane, cyclohexane, benzene and toluene are preferably used as the solvent used.

The reduction reaction leading from the dinitro compound represented by the general formula [X] to the diamino compound represented by the general formula [VI] of the present invention is performed by diborane, lithium borohydride, sodium borohydride, aluminum hydride. It proceeds easily by reacting with a commonly used reducing agent such as lithium, sodium aluminum hydride, sodium dialkoxyaluminum hydride, sodium diethylaluminum hydride, and in the presence of zinc chloride, trichlorosilane, tripropylsilane, triethylsilane. The target product can also be obtained by reacting with a hydrosilane compound such as.

In addition, catalytic reduction using a metal such as nickel, platinum, palladium, or rhodium in a hydrogen gas atmosphere as a catalyst is carried out to convert the intermediate represented by the general formula [X] to the desired general formula [X]. It is also possible to synthesize the compound represented by VI]. It is desirable to carry out any reaction in a solvent, and any solvent may be used so long as it does not participate in the reaction, and examples thereof include alcohol, tetrahydrofuran, dimethoxyethane, dioxane, benzene and toluene. The reaction temperature is-
It can be carried out in the range of 100 ° C to 50 ° C, preferably -80 ° C to 30 ° C.

When used as a raw material for producing a polymer compound having water repellency, which is a characteristic of a fluorine-containing group, and excellent surface characteristics and heat resistance, the water repellency of the polymer compound obtained is effective. In order to increase the above, the carbon number p of the fluorine-containing group in the fluorine-containing diaminobenzene derivative represented by the above general formula (VI) of the present invention needs to be in the range of 1 to 12, more preferably 4 to 12.

The polyorganosiloxane having a diaminophenyl group at one end represented by the general formula [VII] is the same as the polyorganosiloxane having a diaminophenyl group described in JP-A-1-185327. General formula (XI) (In the formula, R ^{1 to} R ⁵ may be the same or different and each is an alkyl group, a substituted alkyl group, a phenyl group or a substituted phenyl group, and m is an integer of 1 or more. Provided that R ¹ and R ² are repeated. It may be different for each unit.)
And a hydropolyorganosiloxane having one terminal represented by
General formula (XII) (In the formula, Y is a group having a carbon-carbon double bond.)
A general formula [XIII] obtained by carrying out a hydrosilylation reaction with a dinitro compound represented by (In the formula, B is a divalent organic group, R ^{1 to} R ⁵ may be the same or different, are an alkyl group, a substituted alkyl group, a phenyl group or a substituted phenyl group, and R ¹ and R ² are each a repeating unit. It may be optionally different.) Is synthesized by using a polyorganosiloxane having a dinitrophenyl group at one terminal represented by the formula (1) as a synthetic intermediate and reducing the dinitro group of this compound to a diamino group by a conventional method. be able to.

Some of the one-terminal hydropolyorganosiloxanes represented by the general formula (XI) are commercially available when the degree of polymerization m is 1. (For example, pentamethyldisiloxane manufactured by Shin-Etsu Chemical Co., Ltd.) When m is 2 or more, for example, an equimolar amount of an alkyllithium compound (RLi) is added to trisubstituted silanol as shown in the following reaction formula. After the living ring-opening polymerization of the cyclosiloxane compound using the silanolate anion obtained as described above as an initiator, the reaction can be stopped by using a diorganohalogenosilane compound having one Si—H bond to synthesize the cyclosiloxane compound. In this case, by changing the charging ratio of the tri-substituted silanol and the cyclosiloxane compound, the general formulas [VII], [XI] and [XII]
The average degree of polymerization of the polyorganosiloxane represented by I] can be controlled. (In the formula, R ^{1 to} R ⁵ , R ¹ ′ and R ² ′ are the same or different and are an alkyl group, a substituted alkyl group, a phenyl group or a substituted phenyl group, and R is an alkyl group, a phenyl group, X
Is a halogen atom. However, R ¹ and R ² may be different for each repeating unit. Also, q is 3
An integer of ˜6, r may be a small number, and rp + 1 is equal to m in the general formulas (III), (XI) and (XIII)).

Examples of the alkyllithium compound (RLi in the above formula) used here include methyllithium, ethyllithium, n-butyllithium, sec-butyllithium, t-butyllithium, n-hexyllithium and phenyllithium. can do.

The following general formula (XIV) used for synthesizing the above-mentioned one-terminal hydropolyorganosiloxane (In the formula, R ^{3 to} R ⁵ are the same or different and each is an alkyl group, a substituted alkyl group, a phenyl group or a substituted phenyl group.) As the trisubstituted silanol, trimethylsilanol, triethylsilanol, dimethyloctylsilanol, Dimethyl octadecyl silanol, 3
-Chloropropylmethylsilanol, 3,3,3-trifluoropropyldimethylsilanol, tridecafluoro-1,1,2,2-tetrahydrooctyldimethylsilanol, diphenylmethylsilanol, triphenylsilanol, pentafluorophenyldimethylsilanol, etc. It can be illustrated. Some of these silanol compounds are commercially available and can also be easily synthesized from the corresponding chlorosilane compounds.

Further, the following general formula (XV) (Wherein R ¹ and R ² are the same or different and each is an alkyl group, a substituted alkyl group, a phenyl group or a substituted phenyl group, and q is an integer of 3 to 6). And the like. Moreover, you may use the mixture of 2 or more types of these cyclosiloxane compounds.

The following general formula (XVI) used as a terminating agent (In the formula, R ¹ ′ and R ² ′ are the same or different and each is an alkyl group, a substituted alkyl group, a phenyl group or a substituted phenyl group, and X is a halogen atom.) As the diorganohalogenosilane compound, , Dimethylchlorosilane, diethylchlorosilane, methyloctylchlorosilane, 3,3,3-trifluoropropylmethylchlorosilane, phenylmethylchlorosilane, diphenylchlorosilane, pentafluorophenylmethylchlorosilane, and the like.

When the one-terminal hydropolyorganosiloxane represented by the general formula (XI) is synthesized by the above-mentioned method, it is preferably carried out in a solvent. Examples of the solvent used are tetrahydrofuran, diethyl ether, hexane, cyclohexane, An organic solvent such as benzene can be used. Further, it is desirable that this reaction is usually carried out at a temperature near room temperature in an inert atmosphere such as argon or nitrogen.

The general formula [X] used for synthesizing the polyorganosiloxane having a dinitrophenyl group at one end represented by the general formula [XIII] from the hydropolyorganosiloxane having one end represented by the general formula [XI]. It is essential that the dinitro compound represented by XII] has a carbon-carbon double bond. An example is a compound represented by the following formula. However, in the formula, the nitro group is assumed to be bonded to any two carbons of the carbons at the 2nd to 6th positions of the bonded benzene ring.

[0025]

[0026]

As a catalyst used as a catalyst for carrying out a hydrosilylation reaction of a hydropolyorganosiloxane having one terminal represented by the general formula [XI] and a dinitro compound represented by the general formula [XII] in the presence of a catalyst, Most commonly, platinum-based catalysts such as platinum, chloroplatinic acid and dicyclopentadienylplatinum dichloride are used, but other metal complexes containing palladium or rhodium can be used. For example, (Ph ₃ P) ₄
Pd, (Ph ₃ P) ₂ PdCl ₂ , and (PhCN) ₂ Pd
Cl ₂ , (Ph ₃ P) ₃ RhCl, (Ph ₂ PH) ₂ R
hCl, (Ph ₃ P) ₂ (CO) PhCl, [(C ₂ H
₅ ) ₃ P] ₂ (CO) PhCl, etc. can be used as a catalyst. The amount of the catalyst used is usually about 1/100 to 1/1000 equivalent with respect to the group having a carbon-carbon double bond. This reaction is preferably carried out in a solvent, which may be hexane, benzene, toluene,
Acetone, trichlorethylene, carbon tetrachloride, tetrahydrofuran (THF) and the like can be used. The reaction temperature is usually in the temperature range of 40 ° C. to 100 ° C., and preferably in an inert gas atmosphere such as argon or nitrogen.

The reduction reaction for synthesizing the polyorganosiloxane represented by the general formula (VII) from the polyorganosiloxane represented by the general formula (XIII) is carried out by the dinitro compound represented by the general formula (X). Can be carried out by the same method as the reduction reaction leading to the fluorine-containing diaminobenzene derivative represented by the general formula (VI) of the present invention.

The repeating unit of the present invention has the general formula (I)
And the polyimide having a fluorine-containing group and / or a siloxane chain in the side chain represented by (II) and (III) is represented by the diaminobenzene derivative represented by the general formula (VI) and / or the general formula (VII). It can be produced using a diaminobenzene derivative as a raw material through the following condensation reaction and imidization reaction.

As the tetracarboxylic acid represented by the general formula [IV] and its derivative, a tetracarboxylic dianhydride is generally used, and the tetracarboxylic dianhydride and the general formula [VI] Reacting and polymerizing a mixture of a fluorine-containing diaminobenzene derivative represented by the formula and / or a siloxane-containing diaminobenzene derivative represented by the general formula [VII] and / or a diamine represented by the general formula [V] in an organic polar solvent. Thereby, a polyamic acid as a polyimide intermediate is obtained.

At this time, the ratio of the number of moles of the diamine represented by the general formula [V] to the total number of moles of the diamine mixture used is a, and the ratio of the fluorinated diaminobenzene derivative represented by the general formula [VI] is b. When the ratio of the siloxane-containing diaminobenzene derivative represented by the general formula [VII] is c, a + b + c = 1 and 0 ≦ a <1,0
It must be in the range of ≤b≤1, 0≤c≤1. That is, in the polyimide used in the present invention obtained by these reactions, the diamine represented by the general formula [V] is not necessarily an essential component, but is represented by the general formula [VI] and / or the general formula [VII]. At least one of the diaminobenzene derivatives represented is always essential.

More specifically, it may be a = 0, but if b = 0, then c> 0, and if c = 0, b> 0. Further, it does not matter if b = 1 and a = c = 0 or c = 1 and a = b = 0, but a =
Must not be 1 and b = c = 0. And each combination of the repeating units of the general formula [I], [II] or [III] of the present invention is the combination of each of the diamines of the general formula [V], [VI] or [VII] with the following: To respond. Combination of repeating units Combination of diamine ────────────────── ────────────────a) [I] + [II] + [III] a) [V] + [VI] + [VII] b) [I] + [II] b) [V] + [VI] c) [I] + [III] c) [V] + [VII] d) [II] d) [VI] e) [III] e) [VII] f) [II] + [III] f) [VI] + [VII]

An object of the present invention is to control the tilt angle of liquid crystal by using the polyimide of the present invention as a liquid crystal alignment treatment agent. The polyimide of the present invention can increase the tilt angle of liquid crystal by using the diaminobenzene derivative represented by the general formula [VI] and / or the general formula [VII] as a raw material.

Therefore, when c = 0, it is necessary that 0 <b ≦ 1 is satisfied, and it is preferable that 0.01 ≦ b ≦ 1 is satisfied in order to substantially increase the tilt angle of the liquid crystal. . b
If = 0, 0 <c ≦ 1 must be satisfied 0.01
It is preferably in the range of ≤c≤1. Further, when b> 0 and c> 0, it is preferable that the range is 0.01 ≦ b + c ≦ 1. The larger the value of b and / or c, the larger the tilt angle of the liquid crystal, and the tilt angle of the liquid crystal can be adjusted in the range of 1 ° to 90 ° by adjusting the value of b and / or c.

The ratio of the total number of moles of the diamine mixture used for this polymerization to the total number of moles of the tetracarboxylic dianhydride is generally in the range of 0.5 to 1.5,
Further, it is preferably in the range of 0.8 to 1.2. As with the usual polycondensation reaction, the closer this ratio is to 1, the higher the molecular weight of the polymer obtained.

When the polyimide of the present invention is used as a liquid crystal aligning agent, a certain degree of coating strength is required. Therefore, the weight average molecular weight of the polyimide must be substantially 10,000 or more. .

Further, 1% of the polyamic acid as the intermediate is added.
By repeating dehydration by heating to 00 to 400 ° C. or chemical imidization using a commonly used imidizing agent such as triethylamine / acetic anhydride, the repeating units have the general formulas (I) and (II) and ( The fluorine-containing and / or siloxane-containing polyimide represented by III) can be produced.

When the polyimide of the present invention is used as an alignment treatment agent, a film thickness of 20 is formed on a substrate having a transparent electrode.
It is necessary to form a polyimide coating film of 0 to 3000.

The method for forming this polyimide coating film is not particularly limited. Usually, the polyamic acid intermediate solution can be directly applied on a substrate and then heated and imidized on the substrate to form a polyimide coating film. The polyamic acid intermediate solution used at this time may use the above-mentioned polymerization solution as it is, or the produced polyamic acid intermediate may be added to a large excess of water or a poor solvent such as methanol, and the precipitate may be recovered and then used as a solvent. It may be redissolved in.

The polymerization solvent for the above polyamic acid intermediate and / or the solvent for re-dissolving the precipitated and recovered polyamic acid intermediate is not particularly limited as long as it can dissolve the polyamic acid intermediate.

Specific examples of these solvents include N, N-
Examples thereof include dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylphosphoramide, and γ-butyrolatone. These may be used alone or as a mixture. Further, even a solvent which cannot obtain a uniform solution by itself may be used by adding it to the above-mentioned solvent within the range where a uniform solution can be obtained.

The temperature at which the substrate is heated and imidized is 1
Any temperature from 00 to 400 ° C can be adopted, but especially 15
The range of 0 to 350 ° C. is preferable. Imidization temperature is 150
If the temperature is lower than ℃, the imidization ratio is low and the alignment of the liquid crystal becomes unstable. On the other hand, if the temperature is 350 ° C. or higher, the coating film becomes colored, which causes a problem in displaying the liquid crystal cell.

When the polyimide of the present invention is dissolved in a solvent, the obtained polyamic acid intermediate can be imidized as it is in a solution to obtain a polyimide solution. The obtained polyimide can be isolated and used in a suitable solvent. It can also be dissolved in to form a polyimide solution. A polyimide coating film can be formed on the substrate by applying this solution on the substrate and volatilizing the solvent.

In this way, a film having a thickness of 200 to 200 is formed on a transparent substrate such as a glass or plastic film having a transparent electrode.
An alignment treatment agent for liquid crystal cells can be obtained by forming a 3000 Å polyimide film and then subjecting the polyimide layer to Rabink treatment.

[0045]

The polyimide of the present invention can be used as a liquid crystal alignment treatment agent having a large liquid crystal tilt alignment angle.
The liquid crystal tilt alignment angle can be adjusted by changing the amount of the repeating unit having a fluorine-containing group and / or a siloxane-containing chain in the polyimide.

[0046]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1 A fluorine-containing diaminobenzene derivative represented by the formula [XVII] 0.058 g (0.1 mmol) of the compound represented by
2,2-bis [4- (4-aminophenoxy) phenyl] propane (hereinafter abbreviated as BAPB) 0.779 g (1.9 mmol) and 1,
2,3,4-Cyclobutanetetracarboxylic acid dianhydride (hereinafter,
Abbreviated as CBDA. ) 0.39 g (2.00 mmol) was dissolved in 7.5 g of N-methylpyrrolidone (hereinafter abbreviated as NMP) and then stirred at 20 ° C. for 4 hours to carry out a polycondensation reaction to prepare a polyamic acid intermediate solution.

When the molecular weight of the obtained polymer was measured by gel permeation chromatography, the weight average molecular weight in terms of polyethylene glycol was 1.1 × 10 ⁵ .

This solution was diluted to 4% by weight with NMP and spin-coated on a glass substrate with a transparent electrode at 3500 rpm.
Heat treatment was performed at 60 ° C. for 60 minutes to form a uniform polyimide coating film.

After rubbing this coating film with a cloth, a rubbing direction was made parallel by sandwiching a spacer of 50 μm, and a liquid crystal (ZLI-2293 manufactured by Merck & Co., Inc.) was injected to prepare a homogeneously oriented cell.

When this cell was rotated in crossed Nicols, clear light and dark were observed, and it was confirmed that the cell was well oriented in the rubbing direction.

The tilt angle of this cell measured by the crystal rotation method was 4.3 °.

Example 2 0.117 g (0.2 mmol) of a fluorine-containing diaminobenzene derivative of the formula [XVII], 0.738 g (1.8 mmol) of BAPB as a diamine, and CBDA0.
A polyamic acid intermediate solution was prepared in the same manner as in Example 1 except that 39 g (2.0 mmol) and NMP 7.1 g were used.

When the molecular weight of the obtained polymer was measured by gel permeation chromatography, the weight average molecular weight in terms of polyethylene glycol was 1.1 × 10 ⁵ .

Then, a cell was prepared in the same manner as in Example 1, and when rotated in crossed Nicols, clear light and dark were observed, and it was confirmed that the cell was well oriented in the rubbing direction.

The tilt angle of this cell measured by the crystal rotation method was 10 °.

Example 3 0.23 g (0.4 mmol) of the fluorinated diaminobenzene derivative of Example 1, 0.66 g (1.6 mmol) of BAPB as a diamine, and CB as an acid anhydride.
A polyamic acid intermediate solution was prepared in the same manner as in Example 1 except that 0.39 g (2.0 mmol) of DA and 7.3 g of NMP were used.

When the molecular weight of the obtained polymer was measured by gel permeation chromatography, the weight average molecular weight in terms of polyethylene glycol was 6.0 × 10 ⁴ .

Then, a cell was prepared in the same manner as in Example 1, and the tilt angle was measured by the crystal rotation method. As a result, it was found that the tilt angle was as high as 15 ° or more, which is the measurement limit of the crystal rotation method.

Observation of this cell with a deflection microscope revealed that
A clear isogyre is observed near the center of the field of view,
It was found that the tilt angle was almost 90 °.

Example 4 As a fluorine-containing diaminobenzene derivative, a compound of the formula [XVIII] 0.31 g (0.8 mmol) of the compound represented by, BAPB 0.49 g (1.2 mmol) as a diamine, and CBDA as an acid anhydride.
0.39 g (2.0 mmol) and NMP 6.7 g were used,
A polyamic acid intermediate solution was prepared in the same manner as in Example 1.

When the molecular weight of the obtained polymer was measured by gel permeation chromatography, the weight average molecular weight in terms of polyethylene glycol was 9.5 × 10 ⁴ .

Then, a cell was prepared in the same manner as in Example 1, and when rotated in crossed Nicols, clear light and darkness was observed, and it was confirmed that the cell was well oriented in the rubbing direction.

The tilt angle of this cell was measured by the crystal rotation method and found to be 9.8 °.

Example 5 Instead of the fluorine-containing diaminobenzene derivative, a silicon-containing chain diaminobenzene derivative represented by the formula [XIX] 0.082 g (0.1 mmol) of the compound shown by the formula, 0.779 g (1.9 mmol) of BAPB as the diamine, and CBDA as the acid anhydride.
Was used in the same manner as in Example 1 except that 0.39 g (2.0 mmol) and 7.1 g of NMP were used to prepare a polyamic acid intermediate solution.

When the molecular weight of the obtained polymer was measured by gel permeation chromatography, the weight average molecular weight in terms of polyethylene glycol was 1.0 × 10 ⁵ .

Then, a cell was prepared in the same manner as in Example 1, and when rotated in a crossed Nicol, clear light and darkness was observed, and it was confirmed that the cell was well oriented in the rubbing direction.

The tilt angle of this cell measured by the crystal rotation method was 8.2 °.

[Example 6] 0.87 g (2.28 mmol) of a fluorine-containing diaminobenzene derivative represented by the formula [XVIII],
2.31 g (2.27 mmol) of a silicon-containing chain diaminobenzene derivative represented by the formula [XIX], and 0.46 g (2.27 mmol) of diaminodiphenyl ether (hereinafter abbreviated as DDE) as a diamine.
mmol) and 1,1,1,3,3,3-hexafluoro-2,2-bis (3,4-dicarboxyphenyl) propane 2 as an acid anhydride
3.03 g (6.82 mmol) of an anhydride (hereinafter abbreviated as 6FDA) was dissolved in 43.3 g of N, N-dimethylacetamide at 60 ° C.
The mixture was stirred for 1 hour for polycondensation reaction to prepare a polyamic acid intermediate solution.

Next, after cooling the solution to room temperature, 3.32 ml (23.8 mmol) of triethylamine and 2.25 ml (23.
(8 mmol) was added and the imidization reaction was performed at 100 ° C. for 30 minutes.
This reaction solution was poured into 800 ml of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a white polyimide powder.

When the molecular weight of the obtained polymer was measured by gel permeation chromatography,
The weight average molecular weight in terms of polystyrene was 8.03 × 10 ⁴ .

1.0 g of this powder was dissolved in 24 g of NMP to make the total solid content 4% by weight, and 3500 rpm was applied to a glass substrate with a transparent electrode.
Was spin coated and heat treated at 180 ° C. for 60 minutes to form a uniform polyimide coating film.

Then, a cell was prepared in the same manner as in Example 1, and the tilt angle was measured by the crystal rotation method. As a result, it was found that the tilt angle was as high as 15 ° or more, which is the measurement limit of the crystal rotation method.

Observation of this cell with a deflection microscope revealed that
A clear isogyre is observed near the center of the field of view,
It was found that the tilt angle was almost 90 °.

Example 7 0.12 g (0.2 mmol) of a fluorine-containing diaminobenzene derivative represented by the formula [XVII], 0.74 g (1.8 mmol) of BAPB as a diamine, and 3,4-dicarboxy-1 as an acid anhydride. , 2,3,4-Tetrahydro-1-naphthalene succinic anhydride (hereinafter abbreviated as TDA) 0.60 g (2.0
was used in the same manner as in Example 1 to prepare a polyamic acid intermediate solution. Add 0.9 ml (1
2 mmol) and 0.9 ml (20 mmol) of acetic anhydride were added at 50 ° C.
The imidization reaction was performed for 3 hours. The reaction solution was poured into 500 ml of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a white polyimide powder.

When the molecular weight of the obtained polymer was measured by gel permeation chromatography, the weight average molecular weight in terms of polyethylene glycol was 5.0 × 10 ⁴ .

1.0 g of this powder was dissolved in 24 g of γ-butyrolactone to make the total solid content 4% by weight, and glass coating with a transparent electrode was spin-coated at 3500 rpm and heat-treated at 180 ° C. for 60 minutes to obtain a uniform polyimide coating film. Was formed.

Then, a cell was prepared in the same manner as in Example 1 and rotated in crossed Nicols. As a result, clear light and dark were observed, and it was confirmed that the cell was well oriented in the rubbing direction.

The tilt angle of this cell was measured by the crystal rotation method and found to be 1.5 °.

Comparative Example 1 BAPB 2.05 g was used in the same manner as in Example 1, except that the fluorine-containing diaminobenzene derivative was not used.
(5.0 mmol) and CBDA 0.97 g (4.93 mmol) and NMP
A polyamic acid intermediate solution was prepared in the same manner as in Example 1 except that 17.1 g was used.

When the molecular weight of the obtained polymer was measured by gel permeation chromatography, the weight average molecular weight in terms of polyethylene glycol was 9.4 × 10 ⁴ .

Then, a cell was prepared in the same manner as in Example 1, and the tilt angle was measured by the crystal rotation method and found to be 2.5 °.

[Comparative Example 2] In Example 6, DDE was 1.00 g (5.0 mmol) without using the fluorine-containing diaminobenzene derivative and the silicon-containing chain diaminobenzene derivative.
And 6FDA (2.20 g, 4.95 mmol) were dissolved in N, N-dimethylacetamide (18.1 g) to obtain a white polyimide powder in the same manner as in Example 1.

The molecular weight of the obtained polymer was measured by gel permeation chromatography to find that the weight average molecular weight in terms of polystyrene was 1.1 × 10 6.
^{Was 5} .

1.0 g of this powder was dissolved in 24 g of NMP to make the total solid content 4% by weight, and 3500 rpm was applied to a glass substrate with a transparent electrode.
Was spin coated and heat treated at 180 ° C. for 60 minutes to form a uniform polyimide coating film.

Then, a cell was prepared in the same manner as in Example 1, and the tilt angle was measured by the crystal rotation method and found to be 2.9 °.

[Comparative Example 3] In Example 7, BAPB 2.05 was used without using the fluorine-containing diaminobenzene derivative.
White polyimide powder was obtained in the same manner as in Example 1 except that g (5.0 mmol) and TDA 1.50 g (5.0 mmol) were used.

When the molecular weight of the obtained polymer was measured by gel permeation chromatography, the weight average molecular weight in terms of polyethylene glycol was 7.5 × 10 ⁴ .

Then, a cell was prepared in the same manner as in Example 7, and the tilt angle was measured by the crystal rotation method and found to be 0.6 °.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yuzen Fukuro, 722, Tsuboi-cho, Funabashi-shi, Chiba 1 Central Research Laboratory, Nissan Chemical Industries, Ltd. (72) Nobuaki Mukai, 722, Tsuboi-cho, Funabashi, Chiba (56) Reference JP-A-1-204931 (JP, A) JP-A-2-80855 (JP, A) JP-A-4-260022 (JP, A)

Claims (1)

(57) [Claims] 1. (In the formula, A ¹ is a tetravalent organic group forming a tetracarboxylic acid, A ² is a divalent organic group forming a diamine, B is a divalent organic group, and R ^{1 to} R ⁵ are the same or different. It is also preferably an alkyl group, a substituted alkyl group, a phenyl group or a substituted phenyl group, m is an integer of 1 or more, n is an integer of 1 to 6,
p is an integer of 1 to 12, provided that m, n, p, A ¹ ,
A ² , B, R ¹ and R ² may be different for each repeating unit. ) And the combination of these repeating units is a) general formulas [I], [II] and [III], b) general formulas [I] and [II], and c) general formulas [I] and [III]. ] D) General formula [II], e) General formula [III] or f) General formulas [II] and [III], and having a weight average molecular weight of 10,000 or more and a fluorine-containing group in the side chain And / or a liquid crystal alignment treatment agent composed of a polyimide having a siloxane chain.