KR101208385B1 - Liquid-crystal alignment material and liquid-crystal display element employing the same - Google Patents

Abstract

Provided are a liquid crystal aligning agent capable of producing a good liquid crystal aligning film with little film clipping with a rubbing treatment, and a liquid crystal display element having reduced display defects resulting from film clipping. A liquid crystal aligning agent containing at least one polymer of a polyamic acid obtained by reaction polymerization of a diamine component and a tetracarboxylic dianhydride component and a polyimide obtained by dehydrating and closing the polyamic acid, wherein the diamine component contains the following general formula [1] The diamine represented by] is contained, The liquid crystal aligning agent characterized by the above-mentioned. The liquid crystal display element which has a liquid crystal aligning film obtained from this liquid crystal aligning agent.

(N and m are integers of 0-4 in a formula [1], R is a hydroxyl group, a C1-C3 alkyl group, a C1-C3 alkoxy group, a C2 or 3 alkenyl group, a carboxylic acid group, a cyan At least one organic group selected from the group consisting of a furnace group and a halogen atom, and in the case where n + m is 2 or more, each of R may be the same or different.)

Description

Liquid crystal aligning agent and liquid crystal display element using the same {LIQUID-CRYSTAL ALIGNMENT MATERIAL AND LIQUID-CRYSTAL DISPLAY ELEMENT EMPLOYING THE SAME}

This invention relates to the liquid crystal display element which has a liquid crystal aligning agent used when producing a liquid crystal aligning film, and the liquid crystal aligning film obtained from this liquid crystal aligning agent.

Liquid crystal display elements are widely used as display devices for achieving thinness and light weight. Usually, the liquid crystal aligning film is used for this liquid crystal display element in order to determine the orientation state of a liquid crystal. In addition, except for some vertically aligned liquid crystal display elements and the like, most of the liquid crystal alignment films are produced by performing some alignment treatment on the surface of the polymer film formed on the electrode substrate.

As a polymer used for a liquid crystal aligning film, polyimide, polyamide, polyamideimide, etc. are known, and the liquid crystal aligning agent which melt | dissolved these polymers and its precursor in the solvent is generally used. As a precursor of a polyimide, polyamic acid is generally used.

As a method of orientation treatment of a polymer film formed on an electrode substrate, the most widely used method is a method of performing a so-called rubbing treatment in which the surface of the film is rubbed by applying pressure with a fabric made of rayon or the like. However, in the process of rubbing treatment, a problem called so-called "film shaving" may occur in which a part of the film is peeled off or a scratch accompanying the rubbing treatment occurs on the surface of the liquid crystal alignment film. Silver is one of the causes which lowers the characteristic of a liquid crystal display element, and also leads to the fall of a yield.

About the film shaping problem accompanying such a rubbing process, the method of using the liquid crystal aligning agent containing a specific thermocrosslinking compound with at least 1 sort (s) of a polyamic acid or a polyimide (for example, refer patent document 1). In the same manner, a method of improving rubbing resistance has been proposed by using a curing agent such as a method of using a liquid crystal aligning agent containing an epoxy group-containing compound (see Patent Document 2, for example).

Patent Document 1: Japanese Patent Application Laid-Open No. 9-185065

Patent Document 2: Japanese Patent Application Laid-Open No. 9-146100

DISCLOSURE OF INVENTION

Problems to be solved by the invention

As mentioned above, in the liquid crystal aligning agent used for a rubbing use, rubbing tolerance of the film is also one of the important characteristics, and the liquid crystal aligning agent with little film shaping with a rubbing process is desired. Moreover, with the advancement of the technique of the enlargement of a liquid crystal display element, and the high precision, the request | requirement about the display defect countermeasure resulting from the film shaping of a liquid crystal aligning film becomes stricter than before, The liquid crystal aligning which can obtain the film excellent in rubbing tolerance The importance of the festival is increasing.

This invention is made | formed in view of the above-mentioned situation. SUMMARY OF THE INVENTION An object of the present invention is to provide a new liquid crystal aligning agent which is capable of obtaining a good liquid crystal alignment film with less film shaping with a rubbing treatment, and further provides a liquid crystal display device in which display defects resulting from film shaping are reduced. It is in doing it.

Means for solving the problem

MEANS TO SOLVE THE PROBLEM This inventor came to complete this invention, as a result of earnestly examining in order to solve the said subject. This invention is as showing below.

1. A liquid crystal aligning agent containing at least one polymer of a polyamic acid obtained by reaction polymerization of a diamine component and a tetracarboxylic dianhydride component and a polyimide obtained by dehydrating and closing the polyamic acid, wherein the diamine component contains the following general formula The diamine represented by [1] is contained, The liquid crystal aligning agent characterized by the above-mentioned.

[Formula 1]

In formula [1], n and m are integers of 0-4, R is a hydroxyl group, a C1-C3 alkyl group, a C1-C3 alkoxy group, a C2 or 3 alkenyl group, a carboxylic acid group, and a cyano group And at least one organic group selected from the group consisting of halogen atoms, and when n + m is 2 or more, R may be the same or different, respectively.)

2. Liquid crystal aligning agent of said 1 which is diamine which has two amino groups in 4,4 'position in general formula [1].

3. Diamine represented by General formula [1] is 1, 2-bis (4-aminophenyl) ethyne, 1- (4-aminophenyl) -2- (4-amino-3- methylphenyl) ethyne, and 1-. 1 or the above which is (4-aminophenyl) -2- (4-amino-3-methoxyphenyl) ethyne, or 1- (4-aminophenyl) -2- (4-amino-3-fluorophenyl) ethyne 2 liquid crystal aligning agent.

4. Liquid crystal aligning agent in any one of said 1-3 in which diamine component contains 10-100 mol% of diamine represented by general formula [1].

5. Liquid crystal aligning agent in any one of said 1-4 whose at least 10 mol% of tetracarboxylic dianhydride component is aromatic tetracarboxylic dianhydride.

6. Liquid crystal aligning agent in any one of said 1-5 whose at least 10 mol% of tetracarboxylic dianhydride component is tetracarboxylic dianhydride which has alicyclic structure or aliphatic structure.

7. Liquid crystal aligning agent in any one of said 1-6 whose imidation ratio of polyimide obtained by dehydrating ring-closing polyamic acid is 30% or more.

8. Liquid crystal display element which has a liquid crystal aligning film obtained from liquid crystal aligning agent in any one of said 1-7.

Effects of the Invention

Since the film excellent in rubbing tolerance can be obtained, the liquid crystal aligning agent of this invention shown by said 1 can obtain the liquid crystal aligning film with few film shavings. Therefore, the liquid crystal display element which has the liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention can reduce the display defect generate | occur | produced by film shaving. In addition, by selecting tetracarboxylic dianhydride or diamine in combination with the diamine of the general formula [1], in addition to the rubbing resistance of the film, a liquid crystal aligning film exhibiting a high voltage retention ratio and a low accumulated charge can be obtained. A display defect can be reduced and it can be set as the liquid crystal display element which does not produce the fall of contrast and burn-in.

Carrying out the invention  Best form for

The present invention will be described in detail below.

When the liquid crystal aligning agent of this invention superposes | polymerizes a diamine component and tetracarboxylic dianhydride component and makes it a polyamic acid, the polyamic acid obtained by using specific diamine as a part of this diamine component (henceforth called a specific polyamic acid) ) Or a liquid crystal aligning agent containing at least one of the polymers of the polyimide obtained by dehydrating and ring-closing the polyamic acid. That is, the liquid crystal aligning agent of this invention may contain either one of the specific polyamic acid or the polyimide obtained by dehydrating and ring-closing the polyamic acid, and may determine both of the polyimide obtained by dehydrating and ring-closing a specific polyamic acid and this polyamic acid. It may contain.

The specific diamine has a structure in which one amino group is bonded to two benzene rings of the tolan structure (diphenylethine), and at the same time, each of the benzene rings has no substituent other than the amino group, or is relatively It is a diamine which has 1-4 small substituents in total. By using this specific diamine, the film shaping of a film can be reduced at the time of a rubbing process.

The reason why the film shaping of the film obtained from the liquid crystal aligning agent of the present invention decreases is not necessarily clear, but is believed to be due to the rigidity of the partial polymer derived from the tolan structure and the packing property of the molecular chains. Moreover, although the crosslinking reaction of an acetylene part can also be considered structurally, it is known that the crosslinking temperature of acetylene is 350 degreeC or more, On the other hand, since the liquid crystal aligning agent of this invention can obtain favorable result also in the heat processing of about 220 degreeC, film shaving is carried out. The effect on is considered not to be due to the crosslinking reaction of acetylene.

Said specific diamine is represented by following General formula [1].

[Formula 2]

In General formula [1], R is a relatively small substituent, As a specific example, it is a hydroxyl group; Alkyl groups having 1 to 3 carbon atoms such as methyl, ethyl, and propyl; Alkoxy groups having 1 to 3 carbon atoms such as methoxy, ethoxy and propoxy; Alkenyl groups having 2 or 3 carbon atoms such as ethenyl and propenyl; Halogen atom; And cyano group. Especially, a C1-C3 alkyl group, a C1-C3 alkoxy group, and a halogen atom are preferable.

In general formula [1], n and m represent the number of substitution of substituent R, The value is an integer of 0-4 each independently. As preferable values of n and m, each is 0 or 1 independently. Moreover, when n + m is two or more, substituent R may respectively be same or different.

In general formula [1], although the substitution position of two amino groups is not specifically limited, The position of the 4,4 'of a tolan structure from a viewpoint of the liquid crystal alignability at the time of making it into the reactivity with tetracarboxylic dianhydride and an oriented film. Is preferred.

Specific examples of the diamine represented by General Formula [1] are shown below.

1,2-bis (4-aminophenyl) ethyne, 1- (2-aminophenyl) -2- (4-aminophenyl) ethyne, 1,2-bis (3-aminophenyl) ethyne, 1- (4- Aminophenyl) -2- (4-amino-3-methylphenyl) ethyne, 1- (4-aminophenyl) -2- (4-amino-2-methylphenyl) ethyne, 1- (4-aminophenyl) -2- (4-amino-3-methoxyphenyl) ethyne, 1- (4-aminophenyl) -2- (4-amino-2-methoxyphenyl) ethyne, 1- (4-aminophenyl) -2- (4 -Amino-3-hydroxyphenyl) ethyne, 1- (4-aminophenyl) -2- (4-amino-2-hydroxyphenyl) ethyne, 1- (4-aminophenyl) -2- (4-amino 3-carboxyphenyl) ethyne, 1- (4-aminophenyl) -2- (4-amino-2-carboxyphenyl) ethyne, 1- (3-aminophenyl) -2- (3-amino-5-methylphenyl ) Ethyne, 1- (3-aminophenyl) -2- (3-amino-2-methylphenyl) ethyne, 1- (3-aminophenyl) -2- (3-amino-2-methoxyphenyl) ethyne, 1 -(3-aminophenyl) -2- (3-amino-5-hydroxyphenyl) ethyne, 1- (3-aminophenyl) -2- (3-amino-2-hydroxyphenyl) ethyne, 1- ( 3-aminophenyl) -2- (3-amino-5-carboxy Phenyl) ethyne, 1- (3-aminophenyl) -2- (3-amino-2-carboxyphenyl) ethyne, 1,2-bis (4-amino-3-methylphenyl) ethyne, 1,2-bis (4 -Amino-2-methylphenyl) ethyne, 1- (4-amino-2-methylphenyl) -2- (4-amino-3-methylphenyl) ethyne, 1,2-bis (4-amino-3-methoxyphenyl) Ethyne, 1,2-bis (4-amino-2-methylphenyl) ethyne, 1- (4-amino-2-methoxyphenyl) -2- (4-amino-3-methoxyphenyl) ethyne, 1,2 -Bis (4-amino-3-hydroxyphenyl) ethyne, 1,2-bis (4-amino-2-hydroxyphenyl) ethyne, 1- (4-amino-2-hydroxyphenyl) -2- ( 4-amino-3-hydroxyphenyl) ethyne, 1,2-bis (4-amino-3-carboxyphenyl) ethyne, 1,2-bis (4-amino-2-methoxyphenyl) ethyne, 1- ( 4-amino-2-carboxyphenyl) -2- (4-amino-3-carboxyphenyl) ethyne, 1,2-bis (3-amino-5-methylphenyl) ethyne, 1,2-bis (3-amino- 2-methylphenyl) ethyne, 1- (3-amino-2-methylphenyl) -2- (3-amino-5-methylphenyl) ethyne, 1,2-bis (3-amino-5-methoxyphenyl) ethyne, 1 , 2-bis (3-amino-2-methoxyphenyl) ethyne, 1- (3-amino-2-methoxyphenyl) -2- (3-amino-5-methoxyphenyl) ethyne, 1,2-bis (3- Amino-5-hydroxyphenyl) ethyne, 1- (3-amino-2-hydroxyphenyl) -2- (3-amino-5-hydroxyphenyl) ethyne, 1,2-bis (3-amino-5 -Carboxyphenyl) ethyne, 1,2-bis (3-amino-2-hydroxyphenyl) ethyne, 1- (3-amino-2-carboxyphenyl) -2- (3-amino-5-carboxyphenyl) ethyne And 1,2-bis (3-amino-5-carboxyphenyl) ethyne, 1- (4-aminophenyl) -2- (4-amino-3-fluorophenyl) ethyne and the like.

Among the above-mentioned specific examples, 1,2-bis (4-aminophenyl) ethyne, 1- (4-aminophenyl) -2- (4-amino-3-methylphenyl) ethyne, 1- (4-aminophenyl) -2 Preferred are-(4-amino-3-methoxyphenyl) ethyne and 1- (4-aminophenyl) -2- (4-amino-3-fluorophenyl) ethyne.

<Diamine component>

In the diamine component for obtaining the said specific polyamic acid, other diamine can be used together other than the diamine represented by General formula [1]. The preferable ratio of the diamine represented by General formula [1] in this diamine component is 10-100 mol%, More preferably, it is 30-100 mol%, More preferably, it is 50-100 mol%. Moreover, you may use the diamine represented by General formula [1] in combination of multiple types.

In the diamine component for obtaining a specific polyamic acid, the other diamine which can be used together with the diamine represented by General formula [1] is not specifically limited, The diamine may be one type or two or more types.

It is as showing below if the specific example of another diamine is given.

1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclo as alicyclic diamine Hexylamine, isophorone diamine, etc. are mentioned.

O-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,6-diaminotoluene, 2,5-diaminotoluene, 2,4-diaminotoluene, 2,3- as aromatic diamines Diaminotoluene, 1,4-diamino-2-methoxybenzene, 2,5-diamino-p-xylene, 1,3-diamino-4-chloro benzene, 3,5-diaminobenzoic acid, 1 , 4-diamino-2,5-dichlorobenzene, 4,4'-diamino-1,2-diphenylethane, 4,4-diamino-2,2'-dimethylbibenzyl, 4,4'- Diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 2,2 ' -Diaminostilbene, 4,4'-diaminostilbene, 4,4'-diaminodiphenylether, 3,4'-diaminodiphenylether, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobenzophenone, 1,3-bis (3-aminophenoxy) benzene, 1,3- Bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,5-bi S (4-aminophenoxy) benzoic acid, 4,4'-bis (4-aminophenoxy) bibenzyl, 2,2-bis [(4-aminophenoxy) methyl] propane, 2,2-bis [4 -(4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, 1,1-bis (4-aminophenyl) cyclohexane, α, α'-bis (4-aminophenyl) -1,4-diisopropylbenzene, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ' -Diaminodiphenylamine, 2,4-diaminodiphenylamine, 1,8-diaminonaphthalene, 1,5-diaminonaphthalene, 1,5-diaminoanthraquinone, 1,3-diaminopyrene, 1,6-diaminopyrene, 1,8-diaminopyrene, 2,7-diaminofluorene, 1,3-bis (4-aminophenyl) tetramethyldisiloxane, benzidine, 2,2'-dimethylbenzidine , 1,2-bis (4-aminophenyl) ethane, 1 , 3-bis (4-aminophenyl) propane, 1,4-bis (4-aminophenyl) butane, 1,5-bis (4-aminophenyl) pentane, 1,6-bis (4-aminophenyl) hexane , 1,7-bis (4-aminophenyl) heptane, 1,8-bis (4-aminophenyl) octane, 1,9-bis (4-aminophenyl) nonane, 1,10-bis (4-aminophenyl ) Decane, 1,3-bis (4-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane , 1,10-bis (4-aminophenoxy) decane, di (4-aminophenyl) propane-1,3-dioate, di (4-aminophenyl) butane-1,4-dioate, di (4 -Aminophenyl) pentane-1,5-dioate, di (4-aminophenyl) hexane-1,6-dioate, di (4-aminophenyl) heptan-1,7-dioate, di (4-amino Phenyl) octane-1,8-dioate, di (4-aminophenyl) nonane-1,9-dioate, di (4-aminophenyl) CAN-1,10-dioate, 1,3-bis [4- (4-aminophenoxy) phenoxy] propane, 1,4-bis [4- (4-aminophenoxy) phenoxy] butane, 1 , 5-bis [4- (4-aminophenoxy) phenoxy] pentane, 1,6-bis [4- (4-aminophenoxy) phenoxy] hexane, 1,7-bis [4- (4- Aminophenoxy) phenoxy] heptane, 1,8-bis [4- (4-aminophenoxy) phenoxy] octane, 1,9-bis [4- (4-aminophenoxy) phenoxy] nonane, 1 And 10-bis [4- (4-aminophenoxy) phenoxy] decane.

2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5-triazine, 2,7-diaminodibenzofuran, 3,6- as heterocyclic diamine Diaminocarbazole, 2,4-diamino-6-isopropyl-1,3,5-triazine, 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole and the like Can be. And, as aliphatic diamine, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-dia Minoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2 , 5-dimethylhexane, 1,7-diamino-2,5-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9- Diamino-5-methylheptane, 1,12-diaminododecane, 1,18-diaminooctadecane, 1,2-bis (3-aminopropoxy) ethane and the like.

Among other diamines as described above, when diamine having an alicyclic structure or an aliphatic structure is used in combination with at least 10 mol% of the diamine component, good rubbing resistance can be obtained and a liquid crystal alignment film having a high voltage retention ratio can be obtained. Can be.

In addition, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,6-diaminotoluene, 2,5-diaminotoluene, and 2,4-diamino are contained in at least 10 mol% of the diamine component. Toluene, 2,3-diaminotoluene, 1,4-diamino-2-methoxybenzene, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'- Diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-2,2'-dimethyldiphenylmethane, 2,6-diaminopyridine, When 2,4-diaminopyridine, 4,4'-diaminodiphenylamine, 3,6-diaminocarbazole, etc. are used together, favorable rubbing tolerance can be obtained, while the voltage retention ratio is high and the accumulation charge is high. A low liquid crystal aligning film can be obtained.

In addition to the diamine described above, when used as a raw material of a polyamic acid or a polyimide to be a liquid crystal alignment film, by using a diamine which is known to increase the pretilt angle of the liquid crystal, a good rubbing resistance can be obtained and the liquid crystal can be arbitrarily used. The liquid crystal aligning film which gives a high pretilt angle of can be obtained. As diamine which the effect of raising the pretilt angle of a liquid crystal is known, the diamine which has a long-chain alkyl group, a perfluoro group, the organic group which has an aromatic cyclic substituent, the organic group which has an aliphatic cyclic substituent, a steroid skeleton group, etc. is mentioned. Can be. Although the specific example of such diamine is shown below, it is not limited to these. In addition, in following formula [8]-[28], j is an integer of 5-20, k is an integer of 1-20.

(3)

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Chemical Formula 9]

[Formula 10]

[Formula 11]

[Chemical Formula 12]

[Chemical Formula 13]

[Formula 14]

[Formula 15]

[Chemical Formula 16]

[Chemical Formula 17]

[Chemical Formula 18]

[Formula 19]

[Chemical Formula 20]

[Chemical Formula 21]

[Formula 22]

(23)

<Tetracarboxylic dianhydride component>

The tetracarboxylic dianhydride contained in the tetracarboxylic dianhydride component for obtaining a specific polyamic acid, and its composition are not specifically limited, You may use combining multiple types of tetracarboxylic dianhydride.

Although the specific example of tetracarboxylic dianhydride is given to the following, it is not limited to these.

1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, having an alicyclic structure or an aliphatic structure, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride , 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid Dianhydride, 3,4-dicarboxy-1-cyclohexyl succinic acid dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dianhydride, 1,2,3,4 -Butanetetracarboxylic dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, 3,3 ', 4,4'-dicyclohexyltetracarb Acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarbox Acid dianhydride, tricyclo [4.2.1.0 ^2,5] nonane -3,4,7,8- tetracarboxylic acid -3,4: 7,8-2 anhydride, hexahydro bicyclo [6.6.0.12,7.03,6.19 , 14.010,13] hexadecane-4,5,11,12-tetracarboxylic acid-4,5: 11,12-2 anhydride and the like.

As aromatic acid dianhydride, pyromellitic dianhydride, 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride, 2,2', 3,3'-biphenyl tetracarboxylic dianhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride, 2,3,3 ', 4'-benzophenone Tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether 2 anhydride, bis (3,4-dicarboxyphenyl) sulfone 2 anhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride And 2,3,6,7-naphthalene tetracarboxylic dianhydride.

When tetracarboxylic dianhydride which has an alicyclic structure or an aliphatic structure is used in at least 10 mol% among tetracarboxylic dianhydride components among the tetracarboxylic dianhydrides mentioned above, favorable rubbing tolerance can be acquired. In addition, a liquid crystal aligning film with a high voltage retention ratio can be obtained.

Moreover, when aromatic tetracarboxylic dianhydride is used for at least 10 mol% of tetracarboxylic dianhydride components, favorable rubbing tolerance can be obtained and the liquid crystal aligning film with more favorable orientation of a liquid crystal can be obtained.

<Polyamic acid>

The specific polyamic acid in this invention is a polyamic acid obtained by reaction-polymerizing the diamine component and tetracarboxylic dianhydride component shown above. Although the reaction method of a diamine component and the tetracarboxylic dianhydride component is not specifically limited, The method of mixing these in an organic solvent is common.

As a method of mixing a diamine component and a tetracarboxylic dianhydride component in an organic solvent, the solution which disperse | distributed or dissolved the diamine component in the organic solvent is stirred, and the tetracarboxylic dianhydride component is disperse | distributed as it is or in an organic solvent. Alternatively, a method of dissolving and adding, a method of adding a diamine component to a solution in which a tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent, a method of alternately adding a tetracarboxylic dianhydride component and a diamine component, or the like These may be mentioned, and any of these methods may be sufficient in this invention. In addition, when the tetracarboxylic dianhydride component or the diamine component consists of plural kinds of compounds, the plural kinds of compounds may be reacted in a mixed state in advance, or may be reacted sequentially one by one.

The temperature at the time of making a diamine component and tetracarboxylic dianhydride component react in an organic solvent is 0-150 degreeC normally, Preferably it is 5-100 degreeC, More preferably, it is 10-80 degreeC. The higher the temperature, the faster the polymerization reaction is terminated, but when the temperature is too high, a high molecular weight polymer may not be obtained. In addition, the reaction can be carried out at any concentration, but if the concentration is too low, a high molecular weight polymer cannot be obtained. If the concentration is too high, the viscosity of the reaction solution becomes too high and uniform agitation becomes difficult. It is 1-50 weight%, More preferably, it is 5-30 weight%. The reaction initial stage may be performed in high concentration | density, and may add an organic solvent after that.

The organic solvent used at the time of the said reaction will not be specifically limited if the produced polyamic acid melt | dissolves. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine and dimethyl sulfone , Hexamethyl sulfoxide, γ-butyrolactone, and the like. These may be used individually or in mixture of multiple types. Moreover, even if it is a solvent which does not melt a polyamic acid, you may mix and use it with the said solvent in the range in which the produced polyamic acid does not precipitate. In addition, since water in the organic solvent inhibits the polymerization reaction and causes hydrolysis of the produced polyamic acid, it is preferable to use an organic solvent dehydrated as much as possible.

As for the ratio of the diamine component and tetracarboxylic dianhydride component used for the polymerization reaction of a polyamic acid, it is preferable that the tetracarboxylic dianhydride component is 0.8-1.2 with respect to the diamine component 1 by molar ratio. As in the usual polycondensation reaction, the closer the molar ratio is to 1: 1, the higher the molecular weight of the polyamic acid obtained. When the molecular weight of a polyamic acid is too small, the intensity | strength of the coating film obtained from it may become inadequate, On the contrary, when the molecular weight of a polyamic acid is too large, the viscosity of the liquid crystal aligning agent manufactured from it will become high too much, and workability at the time of coating film formation And the uniformity of a coating film may deteriorate. Therefore, as for the weight average molecular weight of the polyamic acid used for the liquid crystal aligning agent of this invention, 2,000-500,000 are preferable, More preferably, it is 5,000-300,000.

<Polyimide>

Although the polyamic acid obtained as mentioned above can be used for the liquid crystal aligning agent of this invention as it is, it can also be used as a polyimide dehydrated and closed. However, with the structure of a polyamic acid, it may become difficult to insolubilize in an organic solvent and to use for a liquid crystal aligning agent as conversion to a polyimide advances. In this case, the polyimide may be used as long as it can maintain proper solubility without dehydrating and closing all the amic acid groups in the polyamic acid.

Generally, when the liquid crystal aligning agent is contained in the state which is polyamic acid, and when the liquid crystal aligning agent contains the polyimide which carried out the dehydration ring closure of the polyamic acid, the latter side becomes high in liquid crystal aligning property and voltage retention ratio of a liquid crystal aligning film. On the other hand, the rubbing resistance of the film tends to be low. However, since the rubbing resistance of a film is excellent also when the specific polyamic acid in this invention is contained in the liquid crystal aligning agent in the polyimide state which carried out the dehydration ring closure, liquid crystal aligning after switching a specific polyamic acid into polyimide suitably. It is preferable to make it contain in order that liquid crystal aligning property and voltage retention ratio will improve, without impairing rubbing tolerance. In this case, the preferable imidation ratio of the polyimide which dehydrated and closed the specific polyamic acid is 30% or more, More preferably, it is 60% or more, Especially preferably, it is 80% or more.

In the imidation reaction for dehydrating and ringing polyamic acid, thermal imidization for heating a solution of polyamic acid as it is and chemical imidization for adding a catalyst to a solution of polyamic acid are common, but chemical imidization reaction proceeds at a relatively low temperature. Since imidation hardly produces the molecular weight fall of the polyimide obtained, it is preferable.

Chemical imidation can be performed by stirring a polyamic acid in presence of a basic catalyst and an acid anhydride in an organic solvent. The reaction temperature at this time is -20-250 degreeC, Preferably it is 0-180 degreeC, and reaction time can be implemented in 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times, of the amic acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to 30 mol times of the amic acid group. If the amount of the basic catalyst or the acid anhydride is small, the reaction does not proceed sufficiently. If the amount is too high, it is difficult to completely remove the reaction after the reaction is completed. Pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. are mentioned as a basic catalyst used at this time, Among these, pyridine is preferable because it has a basicity suitable for advancing reaction. Moreover, acetic anhydride, trimellitic anhydride, a pyromellitic dianhydride, etc. are mentioned as an acid anhydride, Among these, since acetic anhydride is used, since refinement | purification after completion | finish of reaction becomes easy, it is preferable. As an organic solvent, the solvent used at the time of the polyamic-acid synthesis | combination mentioned above can be used. The imidation ratio by chemical imidation can be controlled by adjusting catalyst amount, reaction temperature, and reaction time.

Since the added catalyst remains in solution in the polyimide solution obtained in this way, in order to use it for the liquid crystal aligning agent of this invention, it is preferable to add a polyimide solution to the stirring poor solvent, and to collect and collect. Although it does not specifically limit as a poor solvent used for precipitation recovery of a polyimide, methanol, acetone, hexane, butyl cellsolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, etc. can be illustrated. The polyimide precipitated by adding to the poor solvent can be collected by filtration, washing and recovered, followed by normal temperature or heat drying under normal pressure or reduced pressure to obtain a powder. If this powder is melt | dissolved in a good solvent again and the operation of reprecipitation is repeated 2-10 times, polyimide can also be refine | purified. When impurities are not removed by one precipitation recovery operation, it is preferable to perform this purification step. As a poor solvent at this time, when three or more types of poor solvents, such as alcohol, ketones, and a hydrocarbon, are used, since the efficiency of refine | purification further raises, it is preferable.

The polyamic acid may also be recovered and purified by precipitation in the same manner. What is necessary is just to perform this precipitation collection | recovery and refine | purification, when the solvent used for superposition | polymerization of a polyamic acid is not contained in the liquid crystal aligning agent of this invention, or when an unreacted monomer component or an impurity exists in a reaction solution.

<Liquid crystal aligning agent>

The liquid crystal aligning agent of this invention can be obtained by making the dehydration ring-closed polyimide melt | dissolve at least one polymer in the organic solvent for the specific polyamic acid obtained by the above, or this polyamic acid.

The organic solvent is not particularly limited as long as the polymer component contained therein is dissolved. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, and N-ethylpyrrolidone , N-vinylpyrrolidone, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, and the like. These may be used alone or in combination of plural kinds thereof.

Moreover, even if it is a solvent which does not melt | dissolve a polymer component independently, if it is a range in which a polymer component does not precipitate, it can mix with the liquid crystal aligning agent of this invention. It is known that coating film uniformity improves at the time of apply | coating to a board | substrate especially by mixing suitably the solvent which has a low surface tension, It is used also suitably for the liquid crystal aligning agent of this invention. Specific examples of such a solvent include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, and 1-ethoxy-2- Propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl Ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactic acid methyl ester, lactic acid ethyl ester, lactic acid n-propyl ester, lactic acid n-butyl ester, lactic acid isoamyl ester and the like. have.

Although solid content concentration of the liquid crystal aligning agent of this invention can be suitably changed with the thickness of the film to form, it is preferable to set it as 1 to 10 weight%. If it is less than 1 weight%, it will become difficult to form a uniform and defect free film, and when more than 10 weight%, the storage stability of a solution may worsen.

Although the liquid crystal aligning agent of this invention necessarily contains at least one of the specific polyamic acid, ie, the polyamic acid using the diamine represented by General formula [1], or the polyimide which dehydrated and closed this polyamic acid, this invention As long as the effect of this is not impaired, you may contain the other polyamic acid and polyimide which superposed | polymerized separately. Similarly, you may contain resin other than a polyamic acid and polyimide.

In addition, in order to further improve the adhesiveness of the coating film to a board | substrate, you may add well-known additives, such as a silane coupling agent, to the liquid crystal aligning agent of this invention.

The liquid crystal aligning agent of this invention obtained as mentioned above is apply | coated to a board | substrate after filtration, it can be dried and baked, and can be made into a film, and it is used as a liquid crystal aligning film by performing the orientation process by rubbing this film surface. .

In this case, the substrate to be used is not particularly limited as long as it is a substrate having high transparency, and a plastic substrate such as a glass substrate, an acrylic substrate, a polycarbonate substrate, or the like can be used. It is preferable in view of the simplification of the process. Moreover, in the reflective liquid crystal display element, only an opaque one, such as a silicon wafer, can be used if it is only a board | substrate on one side, and the electrode in this case can also use the material which reflects light, such as aluminum.

As a coating method of a liquid crystal aligning agent, the spin coat method, the printing method, the inkjet method, etc. are mentioned, In terms of productivity, the transfer printing method is currently widely used industrially, Preferably also the liquid crystal aligning agent of this invention Used.

Although the process of drying after apply | coating a liquid crystal aligning agent is not necessarily required, when the time from application | coating to baking is not fixed for every board | substrate, or is not immediately baked after application | coating, it is preferable to include a drying process. The solvent should just be evaporating to such an extent that a coating-film shape does not deform | transform by conveyance of a board | substrate etc., and this drying is not specifically limited about the drying means. To give a specific example, a method of drying for 0.5 to 30 minutes, preferably 1 to 5 minutes is taken on a hot plate having a temperature of 50 to 150 ° C, preferably 80 to 120 ° C.

Although baking of the coating film formed using the liquid crystal aligning agent can be performed at arbitrary temperature of 100-350 degreeC, Preferably it is 150 degreeC-300 degreeC, More preferably, it is 200 degreeC-250 degreeC. When a polyamic acid is contained in a liquid crystal aligning agent, although the conversion ratio with respect to a polyimide from a polyamic acid changes with this baking temperature, it is not necessary to always imidize the liquid crystal aligning agent of this invention. However, it is preferable to bake at a temperature 10 degreeC or more higher than heat processing temperature, such as sealing compound hardening, which is required at the liquid crystal cell manufacturing process.

When the thickness of the film after baking is too thick, it becomes disadvantageous in terms of power consumption of a liquid crystal display element, and when too thin, the reliability of a liquid crystal display element may fall, Preferably it is 5-300 nm, Preferably it is 10-100 nm. to be.

The film obtained as mentioned above can be made into a liquid crystal aligning film by rubbing process with the rubbing cloth of various materials, such as rayon, cotton, and nylon.

<Liquid crystal display element>

After obtaining the board | substrate with a liquid crystal aligning film using the liquid crystal aligning agent of this invention by the method as mentioned above, the liquid crystal display element of this invention creates a liquid crystal cell by a well-known method, and makes it a liquid crystal display element. The method of this liquid crystal display element is not specifically limited. As a system of a liquid crystal display element, TN type, STN type, TFT type, horizontal electric field type (IPS), a vertical alignment type (VA), a ferroelectric liquid crystal type, an antiferroelectric liquid crystal type, etc. are mentioned. In particular, in the IPS type liquid crystal display element, since the rubbing conditions at the time of element preparation are more severe than the other liquid crystal display elements, and film shaving is easy to occur, the liquid crystal aligning agent of this invention excellent in the rubbing tolerance of a film is used preferably. Can be.

To give an example of liquid crystal cell creation, a pair of substrates on which a liquid crystal alignment film is formed is sandwiched between 1 to 30 μm, preferably 2 to 10 μm spacers, so that the rubbing direction is an arbitrary angle of 0 to 270 °. It is common to install and fix the circumference | surroundings with a sealing compound, and to inject and seal a liquid crystal. There is no restriction | limiting in particular about the method of liquid crystal encapsulation, The vacuum method which injects a liquid crystal after making the inside of the produced liquid crystal cell into pressure reduction, the dropping method which performs sealing after dripping a liquid crystal, etc. can be illustrated.

Although an Example is given to the following and this invention is demonstrated in more detail, this invention is not limited to these.

Example

Explanation of the symbol used in a present Example

(Tetracarboxylic dianhydride)

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

TDA: 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dianhydride

PMDA: pyromellitic dianhydride

(Diamine)

DAT: 1,2-bis (4-aminophenyl) ethyne

3MDAT: 1- (4-aminophenyl) -2- (4-amino-3-methoxyphenyl) ethyne

3FDAT: 1- (4-aminophenyl) -2- (4-amino-3-fluorophenyl) ethyne

p-PDA: p-phenylenediamine

DDM: 4,4'-diaminodiphenylmethane

DDE: 4,4'-diaminodiphenyl ether

DADB: 1,3-diamino-4-dodecyloxybenzene

(Organic solvent)

NMP: N-methyl-2-pyrrolidone

BCS: Butyl Cellosolve

GBL: γ-butyrolactone

(etc)

{SPI}: Polyimide which dehydrated and closed polyamic acid.

(Measurement of molecular weight and measurement of imidization ratio)

In the following synthesis examples, in order to measure the molecular weight of a polyamic acid or a polyimide, Senshu Co., Ltd. product, normal temperature gel permeation chromatography (GPC) apparatus (SSC-7200), Shodex company column (KD803,805) The number average molecular weight and the weight average molecular weight were made into the polyethyleneglycol and polyethylene oxide conversion value using the following. In addition, the imidation ratio of the polyimide dissolves the polyimide in deuterated DMF (dimethyl sulfoxide-d ₆ ), measures ¹ H-NMR, and protons the ratio of the remaining amic acid group without imidization. It calculated | required and calculated from the ratio of the integrated value of a peak.

Synthesis Example 1 CBDA / DAT

9.10 g (0.046 mol) of CBDA as a tetracarboxylic dianhydride component and 10.00 g (0.048 mol) of DAT as a diamine component were mixed in 176 g of NMP, and it reacted at room temperature for 5 hours, and obtained the polyamic-acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 14826 and the weight average molecular weight of the obtained polyamic acid was 31766. NMP and BCS were added to 50 g of this polyamic-acid solution, and it manufactured so that it might become 5 weight% of polyamic acid, 75 weight% of NMP, and 20 weight% of BCS, and obtained the liquid crystal aligning agent of this invention.

Synthesis Example 2 CBDA / 3MDAT

13.60 g (0.069 mol) of CBDA as a tetracarboxylic dianhydride component and 15.60 g (0.070 mol) of 3MDAT as a diamine component were mixed in 255 g of NMP, and it reacted at room temperature for 5 hours, and obtained the polyamic-acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 16582 and the weight average molecular weight was 32256 of the obtained polyamic acid. NMP and BCS were added to 50 g of this polyamic-acid solution, and it manufactured so that it might become 6 weight% of polyamic acid, 74 weight% of NMP, and 20 weight% of BCS, and obtained the liquid crystal aligning agent of this invention.

Synthesis Example 3 CBDA / p-PDA / DAT (30)

13.75 g (0.070 mol) of CBDA as tetracarboxylic dianhydride component, 4.98 g (0.046 mol) of p-PDA as a diamine component, and 4.11 g (0.020 mol) of DAT are mixed in 205 g of NMP, and reacted for 5 hours at room temperature The mixed acid solution was obtained. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 10121 and the weight average molecular weight of the obtained polyamic acid was 17563. NMP and BCS were added to 50 g of this polyamic-acid solution, and it manufactured so that it might become 6 weight% of polyamic acid, 74 weight% of NMP, and 20 weight% of BCS, and obtained the liquid crystal aligning agent of this invention.

Synthesis Example 4 CBDA / p-PDA / DAT (50)

14.90 g (0.076 mol) of CBDA as tetracarboxylic dianhydride component, 4.30 g (0.040 mol) of p-PDA and 8.30 g (0.040 mol) of DAT as a diamine component were mixed in NMP 308 g, and it reacted at room temperature for 5 hours, and made polya The mixed acid solution was obtained. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 11054 and the weight average molecular weight of the obtained polyamic acid was 21235. NMP and BCS were added to 50 g of this polyamic-acid solution, and it manufactured so that it might become 4 weight% of polyamic acid, 76 weight% of NMP, and 20 weight% of BCS, and obtained the liquid crystal aligning agent of this invention.

Synthesis Example 5 PMDA / DAT

PMDA 15.70g (0.072mol) as a tetracarboxylic dianhydride component and DAT 16.70g (0.080mol) as a diamine component were mixed in NMP300g, and it reacted at room temperature for 5 hours, and obtained the polyamic-acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight of the obtained polyamic acid was 12042, and the weight average molecular weight was 22482. NMP and BCS were added to 50 g of this polyamic-acid solution, and it manufactured so that it might become 5 weight% of polyamic acid, 75 weight% of NMP, and 20 weight% of BCS, and obtained the liquid crystal aligning agent of this invention.

Synthesis Example 6 CBDA / PMDA / DAT

7.80 g (0.040 mol) of CBDA as a tetracarboxylic dianhydride component, 7.00 g (0.032 mol) as a PMDA, and 16.70 g (0.080 mol) of DAT as a diamine component were mixed in 290 g of NMP, and reacted at room temperature for 10 hours to prepare a polyamic acid solution. Got. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 10454 and the weight average molecular weight of the obtained polyamic acid was 18772. NMP and BCS were added to 50 g of this polyamic-acid solution, and it manufactured so that it might become 5 weight% of polyamic acid, 75 weight% of NMP, and 20 weight% of BCS, and obtained the liquid crystal aligning agent of this invention.

Synthesis Example 7 TDA / DAT

29.90 g (0.100 mol) of TDA as a tetracarboxylic dianhydride component and 20.80 g (0.100 mol) of DAT as a diamine component were mixed in 280 g of NMP, and it reacted at room temperature for 5 hours, and obtained the polyamic-acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight of the obtained polyamic acid was 17726, and the weight average molecular weight was 30398. NMP and BCS were added to 50 g of this polyamic-acid solution, and it manufactured so that it might become 5 weight% of polyamic acid, 75 weight% of NMP, and 20 weight% of BCS, and obtained the liquid crystal aligning agent of this invention.

Synthesis Example 8 TDA / DAT {SPI}

NMP was added to 50 g of the polyamic acid solution obtained in Synthesis Example 7 to dilute the polyamic acid to 5% by weight, and further 16.07 g of acetic anhydride and 7.47 g of pyridine were added as an imidization catalyst and reacted at 35 ° C for 3 hours. The reaction solution was poured into 625 ml of methanol, and the obtained precipitate was collected by filtration, washed sufficiently with methanol, and dried under reduced pressure at 100 ° C to obtain a pale yellow polyimide powder having an imidation ratio of 92%. This polyimide had the number average molecular weight of 16276 and the weight average molecular weight of 28839. 3.0 g of this polyimide powder was dissolved in a mixed solvent of 39.5 g of GBL and 7.5 g of BCS to obtain a liquid crystal aligning agent of the present invention.

Synthesis Example 9 CBDA / DAT: CBDA / p-PDA = 4: 6

9.10 g (0.046 mol) of CBDA as a tetracarboxylic dianhydride component and 10.00 g (0.048 mol) of DAT as a diamine component were mixed in 176 g of NMP, and it reacted at room temperature for 5 hours, and obtained the polyamic-acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 14826 and the weight average molecular weight of the obtained polyamic acid was 31766.

Separately, 19.61 g (0.100 mol) of CBDA as a tetracarboxylic dianhydride component and 10.38 g (0.096 mol) of p-PDA as a diamine component were mixed in 345 g of NMP and reacted at room temperature for 5 hours to obtain a polyamic acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 22382 and the weight average molecular weight of the obtained polyamic acid was 40395.

The two kinds of polyamic acid solutions were mixed so that the former and the latter became 4: 6 by the weight ratio of the polyamic acid. Furthermore, NMP and BCS were added to 50 g of this mixed solutions, and it manufactured so that it might become 6 weight% of polyamic acid, 76 weight% of NMP, and 20 weight% of BCS, and obtained the liquid crystal aligning agent of this invention.

Synthesis Example 10 CBDA / DAT / DADB (10)

19.61 g (0.100 mol) of CBDA as a tetracarboxylic dianhydride component, 18.11 g (0.087 mol) of DAT as a diamine component, and 2.92 g (0.010 mol) of DADB were mixed in NMP 365 g, and reacted at room temperature for 3 hours to make a polyamic acid solution. Got. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 18742 and the weight average molecular weight of the obtained polyamic acid was 40386. NMP and BCS were added to 50 g of this polyamic-acid solution, and it manufactured so that it might become 6 weight% of polyamic acid, 74 weight% of NMP, and 20 weight% of BCS, and obtained the liquid crystal aligning agent of this invention.

Synthesis Example 11 CBDA / 3FDAT

13.60 g (0.069 mol) of CBDA as a tetracarboxylic dianhydride component and 16.80 g (0.074 mol) of 3FDAT as a diamine component were mixed in 270 g of NMP, and it reacted at room temperature for 21 hours, and obtained the polyamic-acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 23647 and the weight average molecular weight of the obtained polyamic acid was 49752. NMP and BCS were added to 50 g of this polyamic-acid solution, and it manufactured so that it might become 6 weight% of polyamic acid, 74 weight% of NMP, and 20 weight% of BCS, and obtained the liquid crystal aligning agent of this invention.

Synthesis Example 12 TDA / DAT / p-PDA (50) {SPI}

5.88 g (0.020 mol) of TDA as a tetracarboxylic dianhydride component, 2.08 g (0.010 mol) of DAT as a diamine component, and 1.08 (0.010 mol) of p-PDA were mixed in NMP 51.3 g and reacted at room temperature for 24 hours to carry out polya The mixed acid solution was obtained. NMP was added to 30 g of this polyamic acid solution, and the polyamic acid was diluted to 5 weight%, 10.70 g of acetic anhydride and 4.97 g of pyridine were further added as imidation catalyst, and it was made to react at 35 degreeC for 3 hours. The reaction solution was poured into 400 ml of methanol, and the obtained precipitate was separated by filtration, sufficiently washed with methanol, and dried under reduced pressure at 100 ° C. to obtain a pale yellow polyimide powder having an imidation ratio of 91%. This polyimide was 8830 and number average molecular weight was 15247. 3.0 g of this polyimide powder was dissolved in a mixed solvent of 39.5 g of GBL and 7.5 g of BCS to obtain a liquid crystal aligning agent of the present invention.

Synthesis Example 13 TDA / DAT / p-PDA (40) / DADB (10) {SPI}

30.03 g (0.100 mol) of TDA as a tetracarboxylic dianhydride component, 10.41 g (0.050 mol) of DAT as a diamine component, 4.33 g (0.040 mol) of p-PDA, and 2.92 g (0.010 mol) of DADB were mixed in NMP 270 g, and The mixture was reacted at 50 ° C. for 36 hours to obtain a polyamic acid solution. NMP was added to 50 g, and the polyamic acid was diluted to 5 weight%, 16.05 g of acetic anhydride and 7.64 g of pyridine were added as imidation catalyst, and it was made to react at 35 degreeC for 3 hours. The reaction solution was poured into 625 ml of methanol, and the obtained precipitate was separated by filtration, washed sufficiently with methanol, and dried under reduced pressure at 100 ° C to obtain a pale yellow polyimide powder having an imidation ratio of 92%. This polyimide was 10599 and the weight average molecular weight was 23952. 3.0 g of this polyimide powder was dissolved in a mixed solvent of 39.5 g of GBL and 7.5 g of BCS to obtain a liquid crystal aligning agent of the present invention.

Comparative Synthesis Example 1 CBDA / p-PDA

19.61 g (0.100 mol) of CBDA as a tetracarboxylic dianhydride component and 10.38 g (0.096 mol) of p-PDA as a diamine component were mixed in 345 g of NMP, and it reacted at room temperature for 5 hours, and obtained the polyamic-acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 22382 and the weight average molecular weight of the obtained polyamic acid was 40395. NMP and BCS were added to 50 g of this polyamic-acid solution, it manufactured so that it might become 4 weight% of polyamic acid, 76 weight% of NMP, and 20 weight% of BCS, and it was set as the liquid crystal aligning agent for comparison.

Comparative Synthesis Example 2 PMDA / DDE

20.30 g (0.093 mol) of PMDA as a tetracarboxylic dianhydride component and 20.00 g (0.100 mol) of DDE as a diamine component were mixed in NMP 296 g, and it reacted at room temperature for 24 hours, and obtained the polyamic-acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 43382 and the weight average molecular weight was 89467 of the obtained polyamic acid. NMP and BCS were added to 50 g of this polyamic acid solution, and it manufactured so that it might become 5 weight% of polyamic acid, 75 weight% of NMP, and 20 weight% of BCS, and it was set as the liquid crystal aligning agent for comparison.

Comparative Synthesis Example 3 TDA / DDM

TDA 29.73 g (0.099 mol) as a tetracarboxylic dianhydride component and D.19.83 g (0.100 mol) as a diamine component were mixed in NMP 281 g, and it reacted at room temperature for 24 hours, and obtained the polyamic-acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 10127 and the weight average molecular weight of the obtained polyamic acid was 19746. NMP and BCS were added to 50 g of this polyamic-acid solution, it manufactured so that it might become 5 weight% of polyamic acid, 75 weight% of NMP, and 20 weight% of BCS, and it was set as the liquid crystal aligning agent for comparison.

Comparative Synthesis Example 4 TDA / p-PDA {SPI}

23.50 g (0.078 mol) of TDA as a tetracarboxylic dianhydride component and 8.65 g (0.080 mol) of p-PDA as a diamine component were mixed in NMP 180g, it was made to react at room temperature for 24 hours, and the polyamic-acid solution was obtained. 50 g of this polyamic acid solution was diluted to 5 wt% by NMP, and 14.50 g of acetic anhydride and 6.75 g of pyridine were further added as an imidization catalyst and reacted at 35 ° C for 3 hours. The reaction solution was poured into 625 ml of methanol, and the obtained precipitate was separated by filtration, sufficiently washed with methanol, and dried under reduced pressure at 100 ° C. to obtain a white polyimide powder having an imidization ratio of 93%. This polyimide had the number average molecular weight of 16276 and the weight average molecular weight of 28839. 3.0 g of this polyimide powder was dissolved in a mixed solvent of 39.5 g of GBL and 7.5 g of BCS to prepare a liquid crystal aligning agent for comparison.

Comparative Synthesis Example 5 CBDA / DDM: CBDA / p-PDA = 4: 6

19.22 g (0.098 mol) of CBDA as a tetracarboxylic dianhydride component and 19.83 g (0.100 mol) of DDM as a diamine component were mixed in 221 g of NMP, and it reacted at room temperature for 24 hours, and obtained the polyamic-acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 20832 and the weight average molecular weight of the obtained polyamic acid was 36395.

Separately, 19.61 g (0.100 mol) of CBDA as a tetracarboxylic dianhydride component and 10.38 g (0.096 mol) of p-PDA as a diamine component were mixed in 345 g of NMP and reacted at room temperature for 5 hours to obtain a polyamic acid solution. The polymerization reaction proceeded easily and uniformly. The number average molecular weight was 22382 and the weight average molecular weight of the obtained polyamic acid was 40395.

The two kinds of polyamic acid solutions were mixed so that the former and the latter became 4: 6 by the weight ratio of the polyamic acid. Furthermore, NMP and BCS were added to 50 g of this mixed solution, and it prepared so that it might become 6 weight% of polyamic acid, 76 weight% of NMP, and 20 weight% of BCS, and it was set as the liquid crystal aligning agent for comparison.

(Example 1)

After spin-coating the liquid crystal aligning agent of this invention obtained by the synthesis example 1 to the glass substrate with a transparent electrode, drying for 5 minutes on a 80 degreeC hotplate, baking for 30 minutes by the 220 degreeC hot air circulation type oven, and A coating film having a thickness of 100 nm was formed. This coating film surface was rubbed on the conditions of a roll rotation speed of 700 rpm, a roll traveling speed of 10 mm / sec, and an indentation amount of 0.45 mm using a rayon cloth with a rubbing device having a roll diameter of 120 mm to obtain a substrate with a liquid crystal alignment film.

The liquid crystal aligning film surface near the center of the said board | substrate is randomly observed 5 places by the laser microscope set to 100 times the magnification, and the quantity of the rubbing | scratching flaw and the amount of rubbing waste (attachment) confirmed in the range of about 6.5-mm observation field which is an observation field | view Rubbing tolerance was evaluated from the average value. This result is shown in Table 1 mentioned later. In addition, evaluation criteria were set as follows.

Evaluation standard

A: 10 or less rubbing scratches or rubbing residues.

B: 11 to 19 rubbing scratches or rubbing residues.

C: 20 to 29 rubbing scratches or rubbing residues.

D: 30 or more rubbing scratches or rubbing residues.

(Examples 2 to 13)

Evaluation similar to Example 1 was performed using the liquid crystal aligning agent of this invention obtained in the synthesis examples 2-13. This result is shown in Table 1 mentioned later.

(Comparative Examples 1 to 5)

Evaluation similar to Example 1 was performed using the liquid crystal aligning agent obtained in Comparative Synthesis Examples 1-5. This result is shown in Table 1 mentioned later.

(Example 14)

After spin-coating the liquid crystal aligning agent of this invention obtained by the synthesis example 1 to the glass substrate with a transparent electrode, drying for 5 minutes on a 80 degreeC hotplate, baking for 30 minutes by the 220 degreeC hot air circulation type oven, and A coating film having a thickness of 100 nm was formed. This coating film surface was rubbed on the conditions of 300 rpm of roll rotation speed, 20 mm / sec of roll traveling speeds, and 0.5 mm of indentation amount using the rayon cloth by the rubbing apparatus of roll diameter 120mm, and the board | substrate with a liquid crystal aligning film was obtained.

In order to evaluate the orientation state of a liquid crystal cell, two said board | substrates with a liquid crystal aligning film were prepared, after spread | dispersing a 6 micrometers spacer on the one liquid crystal aligning film surface, a sealing compound was printed on it, and another one board | substrate Was bonded so that the liquid crystal aligning film surface faced and the rubbing direction became anti-parallel, and after that, the sealing compound was cured to produce a blank cell. Liquid crystal MLC-2003 (made by Merck Japan Corporation) was injected into this empty cell by the pressure reduction injection method, and the antiparallel liquid crystal cell was obtained by sealing an injection port.

Evaluation of the liquid crystal alignment state

The said liquid crystal cell was arrange | positioned between the polarizing plates provided with the cross nicol, and it evaluated by visually observing the liquid crystal aligning state immediately after liquid crystal injection. Then, the isotropic treatment was performed by heating a liquid crystal cell at 105 degreeC for 10 minutes, and the liquid crystal aligning state after the isotropic process was visually observed. This result is shown in Table 2 mentioned later.

(Examples 15-23)

Evaluation similar to Example 14 was performed using the liquid crystal aligning agent of this invention obtained in the synthesis examples 2, 5, 6, 7, 8, 10, 11, 12, and 13. This result is shown in Table 2 mentioned later.

(Example 24)

After spin-coating the liquid crystal aligning agent of this invention obtained by the synthesis example 1 to the glass substrate with a transparent electrode, drying for 5 minutes on a 80 degreeC hotplate, baking for 60 minutes in 250 degreeC hot-air circulation type oven, and A coating film having a thickness of 100 nm was formed. This coating film surface was rubbed on the conditions of a roll rotation speed of 700 rpm, a roll traveling speed of 10 mm / sec, and an indentation amount of 0.4 mm using a rayon cloth with a rubbing device having a roll diameter of 120 mm to obtain a substrate with a liquid crystal alignment film.

In order to evaluate the electrical property of a liquid crystal cell, two said board | substrates with a liquid crystal aligning film were prepared, after spread | dispersing a 6 micrometers spacer on the one liquid crystal aligning film surface, the sealing compound was printed on the other one sheet, After attaching a board | substrate to the liquid crystal aligning film surface so that a rubbing direction might go straight, it bonded and hardened the sealing compound, and produced the empty cell. Liquid crystal MLC-2003 (made by Merck Japan Corporation) was injected into this empty cell by the pressure reduction injection method, the injection hole was sealed, and the twisted nematic liquid crystal cell was obtained.

Evaluation of Voltage Holding Characteristics

A voltage of 4V was applied to the liquid crystal cell at a temperature of 23 ° C. for 60 µs, the voltage after 16.67 ms was measured, and the degree of voltage was calculated as the voltage retention ratio. This result is shown in Table 3 mentioned later.

(Examples 25-30)

Evaluation similar to Example 24 was performed using the liquid crystal aligning agent of this invention obtained in the synthesis examples 2, 5, 7, 8, 12, and 13. This result is shown in Table 3 mentioned later.

[Industrial Availability]

Since the film excellent in rubbing tolerance can be obtained, the liquid crystal aligning agent of this invention can be used suitably for the liquid crystal display element of various systems which require a rubbing process in the manufacturing process of an element. The liquid crystal display element of this invention can be used for various apparatuses which display a character, a moving image, a still image, etc., such as a liquid crystal display and a liquid crystal television.

In addition, the JP Patent application 2004-370328, the claim, and all the content of the abstract for which it applied on December 22, 2004 are referred here, and it uses as a indication of the specification of this invention.

Claims (8)

A polyimide obtained by dehydrating and ring-closing and imidizing a polyamic acid obtained by reacting and polymerizing a diamine containing a diamine component represented by the following general formula [1] and an tetracarboxylic dianhydride component, and a polymer having an imidation ratio of 60% or more. Liquid crystal aligning agent for rubbing process to contain. [Formula 1]

(N and m are integers of 0-4 in a formula [1], R is a hydroxyl group, a C1-C3 alkyl group, a C1-C3 alkoxy group, a C2 or 3 alkenyl group, a carboxylic acid group, a cyan It is at least 1 type of organic group chosen from the group which consists of a furnace group and a halogen atom, and when n + m is 2 or more, R may respectively be same or different.) The method of claim 1, The liquid crystal aligning agent which is diamine which has two amino groups in 4,4 'position in general formula [1]. 3. The method according to claim 1 or 2, Diamine represented by General formula [1] is 1, 2-bis (4-aminophenyl) ethyne, 1- (4-aminophenyl) -2- (4-amino-3- methylphenyl) ethyne, and 1- (4). Liquid crystal aligning agent which is -aminophenyl) -2- (4-amino-3-methoxyphenyl) ethyne or 1- (4-aminophenyl) -2- (4-amino-3-fluorophenyl) ethyne. 3. The method according to claim 1 or 2, The liquid crystal aligning agent in which a diamine component contains 10-100 mol% of diamine represented by General formula [1]. 3. The method according to claim 1 or 2, The liquid crystal aligning agent whose at least 10 mol% in tetracarboxylic dianhydride component is aromatic tetracarboxylic dianhydride. 3. The method according to claim 1 or 2, The liquid crystal aligning agent whose at least 10 mol% of the tetracarboxylic dianhydride component is tetracarboxylic dianhydride which has an alicyclic structure or an aliphatic structure. 3. The method according to claim 1 or 2, The liquid crystal aligning agent whose imidation ratio of the polyimide obtained by dehydrating and ring-closing a polyamic acid is 80% or more. The liquid crystal display element which has a liquid crystal aligning film obtained from the liquid crystal aligning agent of Claim 1 or 2.