JP2006113610A - Composition for liquid crystal alignment layer, liquid crystal alignment layer and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem of light leakage in a periphery of bead spacer when a liquid crystal having a large dielectric constant is used for a lateral electric field system liquid crystal display element. <P>SOLUTION: A composition for a liquid crystal alignment layer to be used for manufacturing a lateral electric field system liquid crystal display element is provided, the composition containing a polyamide acid synthesized from a diamino compound component containing one or more kinds of compounds expressed by formula (1) and a tetracarboxylic acid dianhydride component. An alignment layer is obtained by using the above composition. In formula (1), each of ring (A) and ring (B) represents phenylene in which a 1-3C alkyl or alkoxy group may be independently substituted for one or more hydrogen atoms, and a coupling position of an amino group in the ring (A) and ring (B) may be independently a para- or meta-position to the ether coupling. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a composition for a liquid crystal alignment film, a liquid crystal alignment film using the same, and a liquid crystal display element. In the following description, the liquid crystal alignment film may be expressed as an alignment film.

  An active matrix type liquid crystal display element is used for a large display used in a notebook personal computer or various monitors. In addition, polyimide materials having various structures have been proposed in Japanese Patent Application Laid-Open Nos. 61-205924 and 62-297819 (EP 249881A) for alignment films used for these. However, with recent improvements in the characteristics of liquid crystal display elements, the alignment film has been required to have better characteristics than before.

  Conventionally, liquid crystal alignment films have been required to have excellent alignment characteristics and excellent electro-optical characteristics such as a high voltage holding ratio. In recent years, a liquid crystal composition having a large dielectric anisotropy has been used to drive a liquid crystal display element at a low voltage. Further, as the trend toward higher definition and larger screens has progressed, a decrease in contrast that is thought to be caused by light leakage around the bead spacer inside the display surface has become a problem. Thus, it cannot be said that the conventional alignment film is sufficient to reduce these phenomena.

（式中のＲは、２価の芳香族炭化水素基を示す。） As an example of an alignment film from which a high-quality liquid crystal display element can be obtained, a polyimide alignment film obtained from 4,4′-diaminodiphenylmethane and cyclobutanetetracarboxylic dianhydride is proposed in Japanese Patent Publication No. 4-33010. Yes. This is based on a polyimide in which at least 90 mol% of the repeating units are composed of the structural unit represented by the formula (2), and is excellent in transparency and heat resistance. Here, it is stated that 4,4′-diaminodiphenylmethane is useful as a diamino compound.

(R in the formula represents a divalent aromatic hydrocarbon group.)

  Further, JP-A-4-57027 discloses that a polyimide alignment film having a condensed structure of cyclobutanetetracarboxylic dianhydride and 4,4′-diaminodiphenylmethane has a high voltage holding ratio and is suitable for an active matrix liquid crystal display device. Is disclosed.

  However, when a liquid crystal display device is manufactured using these alignment films, there is a problem in that light leakage around the bead spacer occurs inside the display surface. The cause of this is not clear, but it is thought that the alignment of the liquid crystal is disturbed around the bead spacer. In particular, a liquid crystal display element of a horizontal electric field type, that is, a liquid crystal display element of a type in which an electric field applied to the liquid crystal is made substantially parallel to the substrate surface by using a comb-shaped electrode and display is performed using the birefringence of liquid crystal. When a liquid crystal composition having a large dielectric constant is used, the degree of light leakage around the bead spacer is remarkable.

  The object of the present invention is to eliminate the problems of the prior art as described above. That is, it is to provide an alignment film that has good alignment characteristics and high voltage holding characteristics that have been conventionally required for alignment films, and further suppresses light leakage around bead spacers. And providing a liquid crystal display device having the alignment film.

（式中の環Ａおよび環Ｂは、それぞれ独立して１個以上の水素が炭素数１〜３のアルキルまたはアルコキシで置換されてもよいフェニレンであり、環Ａおよび環Ｂへのアミノ基の結合位置は、それぞれ独立してエーテル結合に対してパラ位またはメタ位である。）
（２）テトラカルボン酸二無水物成分が、シクロブタンテトラカルボン酸二無水物（以下、記号ＣＢＴＤＡを用いて表記する。）を２０モル％以上含有し、２種以上のテトラカルボン酸二無水物からなることを特徴とする、前記（１）項に記載の液晶配向膜用組成物。
（３）テトラカルボン酸二無水物成分がＣＢＴＤＡとピロメリット酸二無水物（以下、記号ＰＭＤＡを用いて表記する。）とを含み、この成分中のＣＢＴＤＡの含有量が３０〜７０モル％であることを特徴とする、前記（２）項に記載の液晶配向膜用組成物。
（４）横電界方式の液晶表示素子が誘電率異方性値（以下、記号Δεで表記する。）５〜１４の液晶組成物を含有することを特徴とする、前記（１）〜（３）項のいずれか１項に記載の液晶配向膜用組成物。
（５）前記（１）〜（４）項のいずれか１項に記載の液晶配向膜用組成物を用いて形成される液晶配向膜。
（６）液晶に面する側に設けられた透明電極の上面に前記（５）項に記載の液晶配向膜を有する２枚の基板によって、液晶組成物が挟持されている液晶表示素子。
（７）液晶組成物が５〜１４のΔεを有し、液晶表示素子が横電界方式の液晶表示素子であることを特徴とする、前記（６）項に記載の液晶表示素子。 As a result of intensive studies to solve the problems of the prior art, the present inventors have found that using a specific polyimide as an alignment film is very effective for solving the problems, and have reached the present invention. did. That is, the present invention has the following configuration.
(1) A composition for a liquid crystal alignment film used for producing a horizontal electric field type liquid crystal display element, wherein one or more compounds represented by formula (1), 4,4′-diaminodiphenylmethane, 3,3′-dimethyl-4,4′-diaminodiphenylmethane, 2,2′-dimethyl-4,4′-diaminodiphenylmethane, 3,3 ′, 5,5′-tetramethyl-4,4′-diaminodiphenylmethane Diamino compound second component comprising one or more diamino compounds selected from 1,4-bis (4-((4-aminophenyl) methyl) phenyl) propane and 4,4′-ethylene-di-m-toluidine 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, m-phenylenediamine , P-phenylenediamine, m-xylylenediamine, p-xylylenediamine, 2,2′-diaminodiphenylpropane, benzidine, 1,1-bis (4- (4-aminophenoxy) phenyl) cyclohexane, 1,1 -Bis (4- (4-aminophenoxy) phenyl) -4-methylcyclohexane, 1,1-bis (4- (4-aminophenoxy) phenyl) -4-ethylcyclohexane, 1,1-bis (4- ( 4-aminophenoxy) phenyl) -4-propylcyclohexane, 1,1-bis (4- (4-aminophenoxy) phenyl) -4-butylcyclohexane, 1,1-bis (4- (4-aminophenoxy) phenyl ) -4-pentylcyclohexane, bis (4- (4-aminobenzyl) phenyl) methane, 1,1-bis (4- ( -Aminobenzyl) phenyl) cyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4-methylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4-ethylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4-npropylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4-nbutylcyclohexane, 1,1-bis ( 4- (4-aminobenzyl) phenyl) 4-npentylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) cyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-methylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-ethylcyclohexane, 1,1- (4- (4-aminobenzyl) phenyl) -4-propylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-butylcyclohexane, 1,1-bis (4- (4 -Aminobenzyl) phenyl) -4-pentylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-hexylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) One or more of -4-heptylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-octylcyclohexane and 1,1-bis (4- (4-aminobenzyl) phenyl) methane And the molar ratio of the second component of the diamino compound to the diamino compound represented by the formula (1) is 1/4 to 3, and the diamino compound represented by the formula (1) A liquid crystal containing a polyamic acid synthesized from a diamino compound component and a tetracarboxylic dianhydride component, wherein the total amount of the mino compound and the second component of the diamino compound is 25 mol% or more of the diamino compound component Composition for alignment film.

(In the formula, ring A and ring B are each independently phenylene in which one or more hydrogen atoms may be substituted with alkyl or alkoxy having 1 to 3 carbon atoms, and the amino group to ring A and ring B is The bonding positions are each independently para or meta with respect to the ether bond.)
(2) The tetracarboxylic dianhydride component contains 20 mol% or more of cyclobutanetetracarboxylic dianhydride (hereinafter referred to using the symbol CBTDA), and includes two or more types of tetracarboxylic dianhydrides. The composition for a liquid crystal alignment film according to item (1), wherein
(3) The tetracarboxylic dianhydride component contains CBTDA and pyromellitic dianhydride (hereinafter referred to using the symbol PMDA), and the content of CBTDA in this component is 30 to 70 mol%. The composition for a liquid crystal alignment film according to item (2), which is characterized in that it exists.
(4) The transverse electric field type liquid crystal display element contains a liquid crystal composition having a dielectric anisotropy value (hereinafter referred to as symbol Δε) of 5 to 14, wherein (1) to (3) The composition for liquid crystal aligning film of any one of claim | item.
(5) The liquid crystal aligning film formed using the composition for liquid crystal aligning films of any one of said (1)-(4) term.
(6) A liquid crystal display element in which a liquid crystal composition is sandwiched between two substrates having the liquid crystal alignment film described in the above item (5) on the upper surface of a transparent electrode provided on the side facing the liquid crystal.
(7) The liquid crystal display device according to (6), wherein the liquid crystal composition has a Δε of 5 to 14, and the liquid crystal display device is a horizontal electric field type liquid crystal display device.

  In a liquid crystal display element, when a liquid crystal composition having a relatively large Δε is used, light leakage around the bead spacer tends to become remarkable. In the horizontal electric field type liquid crystal display element, this problem is solved by forming an alignment film using the composition for liquid crystal alignment film of the present invention. The liquid crystal display element of the present invention is particularly excellent as an active drive type liquid crystal display element of high image quality and large capacity display, and can be used for a liquid crystal display element of a terminal of OA equipment, a display element mounted on an automobile, and the like.

  The composition for alignment films of the present invention is a composition comprising a polyamic acid synthesized from a diamino compound component containing one or more compounds represented by the above formula (1) and a tetracarboxylic dianhydride component. . This composition is used as a raw material for the alignment film when a transverse electric field type liquid crystal display element is manufactured. This liquid crystal display element preferably contains a liquid crystal composition having Δε of 6 to 14.

  The compound represented by the formula (1) is a diamine derivative having a diphenyl ether skeleton. The bonding positions of the two amino groups to the benzene ring are the para position or the meta position, respectively, with respect to the ether bond. Accordingly, the compound represented by the formula (1) includes 4,4'-diamino derivatives, 3,4'-diamino derivatives and 3,3'diamino derivatives. These diamine derivatives may have one or more of alkyl or alkoxy. A typical example of the compound represented by the formula (1) is 4,4′-diaminodiphenyl ether (hereinafter referred to by using the symbol DDE). Other specific examples include 3-methyl-4,4′-diaminodiphenyl ether, 2-methyl-4,4′-diaminodiphenyl ether, 2-methoxy-4,4′-diaminodiphenyl ether, 2,6′-dimethyl- Examples include 4,4′-diaminodiphenyl ether, 3,5′-dimethyl-4,4′-diaminodiphenyl ether, and 2,6′-dimethoxy-4,4′-diaminodiphenyl ether.

  The diamino compound component preferably includes the diamino compound represented by the formula (1) and the second component of the diamino compound. Considering that the viscosity of the polyamic acid solution is likely to increase during polymerization, 2,2′-dimethyl-4,4′-diaminodiphenylmethane and 4,4′-ethylene-di-m-toluidine are the second component of the diamino compound. preferable. A preferred ratio of the second component of the diamino compound to the diamino compound represented by the formula (1) is a molar ratio of 0 to 4, and a more preferred ratio is a molar ratio of 1/4 to 3. If this molar ratio is less than 1/4, the voltage holding ratio may decrease or the residual charge may increase. The total amount of the diamino compound represented by the formula (1) and the second component of the diamino compound is preferably 25 mol% or more, more preferably 80 mol% or more in the diamino compound component.

  The diamino compound component may contain one or more diamino compounds other than these in addition to the diamino compound represented by the formula (1) and the second diamino compound component. Specific examples of other diamino compounds are 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, m-phenylene. Diamine, p-phenylenediamine, m-xylylenediamine, p-xylylenediamine, 2,2′-diaminodiphenylpropane, benzidine, 1,1-bis (4- (4-aminophenoxy) phenyl) cyclohexane, 1, 1-bis (4- (4-aminophenoxy) phenyl) -4-methylcyclohexane, 1,1-bis (4- (4-aminophenoxy) phenyl) -4-ethylcyclohexane, 1,1-bis (4- (4-Aminophenoxy) phenyl) -4-propylcyclohexane, 1,1-bis (4- (4-aminophenoxy) Enyl) -4-butylcyclohexane, 1,1-bis (4- (4-aminophenoxy) phenyl) -4-pentylcyclohexane, bis (4- (4-aminobenzyl) phenyl) methane, 1,1-bis ( 4- (4-aminobenzyl) phenyl) cyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4-methylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4 -Ethylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4-npropylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4-nbutylcyclohexane, 1, 1-bis (4- (4-aminobenzyl) phenyl) 4-npentylcyclohexane, 1,1-bis (4- (4-aminobenzyl) Enyl) cyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-methylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-ethylcyclohexane, 1, 1-bis (4- (4-aminobenzyl) phenyl) -4-propylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-butylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-pentylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-hexylcyclohexane, 1,1-bis (4- (4-aminobenzyl) Phenyl) -4-heptylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-octylcyclohexane, and 1 , 1-bis (4- (4-aminobenzyl) phenyl) methane and the like. These examples do not limit the scope of the present invention.

  The tetracarboxylic dianhydride component, which is another raw material for synthesizing the polyamic acid, preferably contains 20 mol% or more of CBTDA. A more preferable range of this ratio is 30 to 70 mol%. It is preferable to use PMDA as a tetracarboxylic dianhydride other than CBTDA. In addition, when the ratio of CBTDA exceeds 70 mol%, a screen burn-in phenomenon tends to occur.

  The tetracarboxylic dianhydride component may contain one or more other tetracarboxylic dianhydrides in addition to CBTDA and PMDA as long as the properties of the present invention are not impaired. The other tetracarboxylic dianhydrides are selected from aromatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides and aliphatic tetracarboxylic dianhydrides. Specific examples of aliphatic and alicyclic tetracarboxylic dianhydrides include ethylene tetracarboxylic dianhydride, decahydronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 4,8-dimethyl- 1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, butane -1,2,3,4-tetracarboxylic dianhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, cyclohexane-1, 2,5,6-tetracarboxylic dianhydride, 3,3′-bicyclohexyl-1,1 ′, 2,2′-tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride 5- (2,5-dioxotetra (Drofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5-tetrahydro-2,5-dioxo-3-furanyl)- Naft [1.2. -C] -furan-1,3-dione, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, and the like.

  Specific examples of the aromatic tetracarboxylic dianhydride include 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furan Tetracarboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoropyridene diphthalic dianhydride, 3,3 ′, 4 4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylsulfin oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) Anhydrides, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, and the like.

  The composition for an alignment film of the present invention may contain an aminosilicon compound or a diaminosilicon compound in addition to the polyamic acid in order to improve adhesion to a glass substrate or the like. Examples of the aminosilicon compound include paraaminophenyltrimethoxysilane, paraaminophenyltriethoxysilane, metaaminophenyltrimethoxysilane, metaaminophenyltriethoxysilane, aminopropyltrimethoxysilane, and aminopropyltriethoxysilane. Diaminosilicon compounds include 1,3-bis (3-aminopropyl) -1,1,1-tetraphenylsiloxane, 1,3-bis (3-aminopropyl) -1,1,1-tetramethyldisiloxane, 1,3-bis (4-aminobutyl) -1,1,1-tetramethyldisiloxane and the like.

  The composition for an alignment film of the present invention may contain an organic solvent in addition to the polyamic acid. An example of the organic solvent is a reaction solvent used when synthesizing polyamic acid. The reaction solvent is preferably a polar organic solvent. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone (hereinafter referred to using the symbol NMP), dimethyl sulfoxide, hexamethylphosphoramide, phenol, tetrahydrofuran. , Dioxane and γ-butyrolactone. These solvents may be used in combination of two or more. An organic solvent such as toluene, xylene, 2-alkoxyethanol, or carbitol can be used together with the polar organic solvent as long as the solubility of the polyamic acid is not lowered.

  Furthermore, the composition for a liquid crystal alignment film of the present invention is a polyamic acid, a polyamidoimide, a polyester, a polyamide, or an acrylic polymer having a different composition in addition to the polyamic acid as long as the characteristics of the present invention are not impaired. And other polymer components. The mixing ratio of the polymer component is preferably 25% by weight or less with respect to the polyamic acid.

  The polyamic acid in the composition for alignment films of the present invention is converted to polyimide by heating and / or chemical treatment with a dehydrating agent such as acetic anhydride. In order to obtain the alignment film of the present invention, first, an alignment film composition is applied on a glass substrate on which a transparent electrode such as ITO (Indium Tin Oxide) is formed. Thereafter, the obtained coating film is dried and dehydrated, whereby the polyamic acid in the coating film is cyclized to become polyimide, and an alignment film is formed. As a coating method, a printing method, a dipping method, a spraying method, or the like is used. The dehydration ring closure temperature can be arbitrarily selected in the range of 100 to 400 ° C, preferably 150 to 330 ° C. The heating time is 1 minute to 6 hours, preferably 1 minute to 3 hours. In applying the alignment film composition, a coupling agent such as a silane coupling agent or a titanium coupling agent may be used in order to improve the adhesion between the alignment film and the glass substrate. The alignment film thus formed may be rubbed on the surface. A liquid crystal display element can be obtained by a known method using the substrate having the alignment film of the present invention.

  When the alignment film composition of the present invention is applied to a twisted nematic (TN) type liquid crystal display element utilizing the optical rotation of the liquid crystal in which the electric field direction is substantially perpendicular to the substrate surface, It is difficult to expect a remarkable improvement effect against light leakage. However, light leakage around the bead spacer is improved when applied to a lateral electric field type liquid crystal display device using the birefringence of the liquid crystal by making the electric field direction substantially parallel to the substrate surface using the comb-shaped electrode. .

  In the horizontal electric field type liquid crystal display element, the effect of the present invention for preventing light leakage around the bead spacer is remarkable when the liquid crystal display element contains a liquid crystal composition having a large Δε. Such a liquid crystal composition has Δε of 5 to 14, and examples thereof include a composition containing a fluorine-containing liquid crystal compound (hereinafter referred to as a fluorine-based liquid crystal composition). Even when a fluorine-based liquid crystal composition is used, when Δε is small (in this case, the driving voltage is relatively high), light leakage around the bead spacer does not remarkably occur. The effect of the membrane is not so great. However, in the case of a fluorine-based liquid crystal composition having Δε of 5 or more (driving voltage is low), light leakage around the bead spacer becomes significant, so that the effect of the present invention is remarkably exhibited. Such a tendency is also observed when a liquid crystal composition other than the fluorine-based liquid crystal composition is used.

EXAMPLES Hereinafter, although an Example demonstrates this invention, the scope of the present invention is not limited by these Examples.
<Test method>
1) Viscosity Using an E-type viscometer, the viscosity was measured at a measurement temperature of 25 ° C.
2) Weight average molecular weight Measured by gel permeation chromatography.
3) Discrimination of light leakage around the bead spacer An ITO electrode was provided on a glass substrate, an alignment film was formed on the glass substrate, a rubbing treatment was performed, and the bead spacers were sprayed in a dry manner to produce an anti-parallel cell having a cell thickness of 5 μm. . After injecting the liquid crystal composition, transmission observation was performed with an optical microscope with no voltage applied, and the degree of light leakage around the bead spacer was determined.
4) Dielectric anisotropy value (Δε)
A cell in which the liquid crystal composition is aligned in parallel and a cell in which the same liquid crystal composition is aligned in the vertical direction are prepared. From the dielectric constant when a frequency of 1.0 kHz and a voltage of 10 V are applied to the parallel aligned cell, Δε is obtained by subtracting the dielectric constant when a voltage of 1.0 kHz and a voltage of 0.5 V is applied to the oriented cells. The measurement temperature is 25 ° C.

(Synthesis Example 1)
DDE 1.404 g (7.04 mmol), 4,4′-diaminodiphenylmethane 1.395 g (7.04 mmol), dried in a 100 ml four-necked flask equipped with a thermometer, stirrer, raw material inlet and nitrogen gas inlet NMP94g was put and it stirred under dry nitrogen stream. While maintaining the temperature of the reaction system at 20 ° C. or less, 1.535 g (7.04 mmol) of PMDA and 1.380 g (7.04 mmol) of CBTDA were added and stirred for 15 hours, and DDE, 4,4′-diaminodiphenylmethane, PMDA and CBTDA A polymer A solution having a molar ratio of 1: 1: 1: 1 and a solid content of 6 wt% was obtained. The viscosity of this solution was 70 mPa · s, and the weight average molecular weight of Polymer A was 94,000.

(Synthesis Example 2)
DDE, 2,2′-dimethyl-4,4 ′ is the same as Synthesis Example 1 except that 2,2′-dimethyl-4,4′-diaminodiphenylmethane is used instead of 4,4′-diaminodiphenylmethane. -A polymer B solution having a molar ratio of diaminodiphenylmethane, PMDA and CBTDA of 1: 1: 1: 1 and a solid content of 6 wt% was obtained. The viscosity of this solution was 60 mPa · s, and the weight average molecular weight of the polymer B was 82,000.

(Synthesis Example 3)
In a 300 ml four-necked flask equipped with a thermometer, stirrer, raw material inlet and nitrogen gas inlet, 2.808 g (14.08 mmol) of DDE, 1.395 g (7.04 mmol) of 4,4′-diaminodiphenylmethane, 2,2 '-Dimethyl-4,4'-diaminodiphenylmethane (1.593 g, 7.04 mmol) and dried NMP (182 g) were added and stirred under a dry nitrogen stream. While maintaining the temperature of the reaction system at 20 ° C. or lower, 3.07 g (14.08 mmol) of PMDA and 2.76 g (14.08 mmol) of CBTDA were added and stirred for 15 hours, and DDE, 4,4′-diaminodiphenylmethane, 2,2 A polymer C solution having a molar ratio of '-dimethyl-4,4'-diaminodiphenylmethane, PMDA and CBTDA of 2: 1: 1: 2: 2 and a solid content of 6 wt% was obtained. The viscosity of this solution was 58 mPa · s, and the weight average molecular weight of the polymer C was 72,000.

(Synthesis Example 4)
Except for using 1.508 g (7.04 mmol) of 3-methyl-4,4′-diaminodiphenyl ether in place of 2,2′-dimethyl-4,4′-diaminodiphenylmethane, the same procedure as in Synthesis Example 3 was performed. , DDE, 4,4′-diaminodiphenylmethane, 3-methyl-4,4′-diaminodiphenyl ether, PMDA and CBTDA in a molar ratio of 2: 1: 1: 2: 2 and a solid content of 6 wt% Obtained. The viscosity of this solution was 67 mPa · s, and the weight average molecular weight of the polymer D was 86,000.

(Synthesis Example 5)
Except for using only 4,4′-diaminodiphenylmethane as the diamino compound, the same as in Synthesis Example 1, except that the molar ratio of 4,4′-diaminodiphenylmethane, PMDA and CBTDA was 2: 1: 1, and the solid content was 6 wt. % Polymer E solution was obtained. The viscosity of this solution was 65 mPa · s, and the weight average molecular weight of the polymer E was 115,000.

(Synthesis Example 6)
Except for using 4,4'-diaminodiphenylmethane and 2,2'-dimethyl-4,4'-diaminodiphenylmethane as the diamino compound, 4,4'-diaminodiphenylmethane, 2,2 ' -A polymer F solution having a molar ratio of dimethyl-4,4'-diaminodiphenylmethane, PMDA and CBTDA of 1: 1: 1: 1 and a solid content of 6 wt% was obtained. The viscosity of this solution was 60 mPa · s, and the polymer F had a weight average molecular weight of 100,000.

Example 1
The polymer solutions obtained in Synthesis Examples 1 to 6 were each diluted to 3 wt% using 2-butoxyethanol. Each of these solutions was applied on a transparent electrode formed on a glass substrate by a spin coating method, and heat-treated at 200 ° C. for 1 hour to form an alignment film having a thickness of about 60 nm. Here, alignment films obtained from polymer A, polymer B, polymer C, polymer D, polymer E, and polymer F are represented by PA, PB, PC, PD, PE, and P, respectively. -F. Two substrates each having these alignment films formed thereon were prepared, and the respective alignment film surfaces were rubbed. A bead spacer having a diameter of 5 μm was sprayed on one side and then the other was overlapped to prepare anti-parallel cells corresponding to the respective alignment films. A predetermined liquid crystal composition was injected into these cells, heat treatment was performed at 110 ° C. for 30 minutes, and light leakage around the bead spacer was determined for each.

Using the liquid crystal 1 and the liquid crystal 2 shown below, each anti-parallel liquid crystal cell was prepared, and the influence by the difference in the magnitude of Δε was examined. The results are shown in Table 1.
(Liquid crystal 1)
NI point: 80.2 ° C
Viscosity at 20 ° C .: 23.3 mPa · s
Δn: 0.0965
Δε: 5.7
(Liquid crystal 2)
NI point: 79.9 ° C
Viscosity at 20 ° C .: 26.28 mPa · s
Δn: 0.0841
Δε: 9.9

この表における評価の意味は下記の通りである。
○：ほとんどすべてのビーズスペーサーの周辺から光漏れは発生していない。
×：ほとんどすべてのビーズスペーサーの周辺から光漏れが発生し、その面積も大きい。
△：ほとんどすべてのビーズスペーサーの周辺から光漏れが発生するが、その面積は大きくない。
この結果から、合成例１〜４の液晶配向膜用組成物を用いて配向膜とすることにより、ビーズスペーサー周辺の光漏れがほとんどない液晶表示素子を得ることが可能であることが明らかである。

The meaning of the evaluation in this table is as follows.
○: No light leaks from the vicinity of almost all bead spacers.
X: Light leakage occurs from the vicinity of almost all bead spacers, and the area is large.
(Triangle | delta): Although light leaks from the periphery of all the bead spacers, the area is not large.
From this result, it is clear that a liquid crystal display element with almost no light leakage around the bead spacer can be obtained by using the composition for liquid crystal alignment film of Synthesis Examples 1 to 4 as an alignment film. .

Claims (7)

A composition for a liquid crystal alignment film used for producing a horizontal electric field type liquid crystal display device, which is one or more compounds represented by the formula (1), 4,4′-diaminodiphenylmethane, 3, 3 '-Dimethyl-4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 3,3', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 1, A diamino compound second component comprising one or more diamino compounds selected from 3-bis (4-((4-aminophenyl) methyl) phenyl) propane and 4,4′-ethylene-di-m-toluidine; , 2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, m-phenylenediamine, p Phenylenediamine, m-xylylenediamine, p-xylylenediamine, 2,2′-diaminodiphenylpropane, benzidine, 1,1-bis (4- (4-aminophenoxy) phenyl) cyclohexane, 1,1-bis ( 4- (4-aminophenoxy) phenyl) -4-methylcyclohexane, 1,1-bis (4- (4-aminophenoxy) phenyl) -4-ethylcyclohexane, 1,1-bis (4- (4-amino) Phenoxy) phenyl) -4-propylcyclohexane, 1,1-bis (4- (4-aminophenoxy) phenyl) -4-butylcyclohexane, 1,1-bis (4- (4-aminophenoxy) phenyl) -4 -Pentylcyclohexane, bis (4- (4-aminobenzyl) phenyl) methane, 1,1-bis (4- (4-a Nobenzyl) phenyl) cyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4-methylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4-ethylcyclohexane, 1, 1-bis (4- (4-aminobenzyl) phenyl) 4-npropylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) 4-nbutylcyclohexane, 1,1-bis (4- (4-Aminobenzyl) phenyl) 4-npentylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) cyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4 -Methylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-ethylcyclohexane, 1,1-bis ( -(4-aminobenzyl) phenyl) -4-propylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-butylcyclohexane, 1,1-bis (4- (4-aminobenzyl) ) Phenyl) -4-pentylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-hexylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4- And one or more of heptylcyclohexane, 1,1-bis (4- (4-aminobenzyl) phenyl) -4-octylcyclohexane and 1,1-bis (4- (4-aminobenzyl) phenyl) methane The molar ratio of the second component of the diamino compound to the diamino compound represented by the formula (1) is 1/4 to 3, and the diamination represented by the formula (1) A liquid crystal comprising a polyamic acid synthesized from a diamino compound component and a tetracarboxylic dianhydride component, wherein the total amount of the compound and the second component of the diamino compound is 25 mol% or more of the diamino compound component Composition for alignment film.

(In the formula, ring A and ring B are each independently phenylene in which one or more hydrogen atoms may be substituted with alkyl or alkoxy having 1 to 3 carbon atoms, and the amino group to ring A and ring B is The bonding positions are each independently para or meta with respect to the ether bond.)   The liquid crystal alignment according to claim 1, wherein the tetracarboxylic dianhydride component contains 20 mol% or more of cyclobutanetetracarboxylic dianhydride and is composed of two or more kinds of tetracarboxylic dianhydrides. Film composition.   The tetracarboxylic dianhydride component includes cyclobutane tetracarboxylic dianhydride and pyromellitic dianhydride, and the content of cyclobutane tetracarboxylic dianhydride in this component is 30 to 70 mol%. The composition for a liquid crystal alignment film according to claim 2, wherein the composition is a liquid crystal alignment film.   The liquid crystal alignment film composition according to any one of claims 1 to 3, wherein the horizontal electric field type liquid crystal display element contains a liquid crystal composition having a dielectric anisotropy value of 5 to 14.   The liquid crystal aligning film formed using the composition for liquid crystal aligning films of any one of Claims 1-4.   A liquid crystal display element in which a liquid crystal composition is sandwiched between two substrates having the liquid crystal alignment film according to claim 5 on an upper surface of a transparent electrode provided on a side facing a liquid crystal. The liquid crystal display element according to claim 6, wherein the liquid crystal composition has a dielectric anisotropy value of 5 to 14, and the liquid crystal display element is a horizontal electric field type liquid crystal display element.