KR102143667B1 - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

A liquid crystal aligning agent capable of providing for the production of a liquid crystal display element having reduced alignment disturbance without following a complicated manufacturing method, a liquid crystal aligning film obtained from the liquid crystal aligning agent, and a liquid crystal display element having the liquid crystal aligning film are provided. A liquid crystal aligning agent containing at least one of a first polymer reacting with light in a wavelength range of 250 to 380 nm, a compound having an absorption maximum in a wavelength range of 250 to 380 nm, and a second polymer. Moreover, a liquid crystal display element formed by forming a liquid crystal aligning film using the liquid crystal aligning agent, and performing photo-alignment treatment.

Description

A liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element TECHNICAL FIELD {LIQUID CRYSTAL ALIGNING AGENT, LIQUID CRYSTAL ALIGNMENT FILM AND LIQUID CRYSTAL DISPLAY ELEMENT}

The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element.

Liquid crystal display elements are known as light-weight, thin, and low-power display devices, and have recently made remarkable developments, such as being used for large-scale television applications.

The liquid crystal display element is constituted by sandwiching and sealing a liquid crystal layer between a pair of substrates, and aligning the liquid crystal of the liquid crystal layer in a predetermined direction between substrates. In a liquid crystal display device, a liquid crystal responds by applying a voltage to an electrode formed on a pair of substrates, and a desired image can be displayed using a change in orientation caused by the response of the liquid crystal.

In a liquid crystal display element, the alignment of the liquid crystal in the liquid crystal layer is realized by forming a liquid crystal alignment film having the ability to control the alignment of the liquid crystal on the surface of a pair of substrates holding the same. That is, the liquid crystal alignment layer is formed on the most surface of the pair of substrates of the liquid crystal display device in contact with the liquid crystal, and plays a role of aligning the liquid crystals between the substrates in a predetermined direction, such as a direction parallel to the substrate. Is absent.

In addition, in addition to the function of aligning the liquid crystal in a predetermined direction, the liquid crystal aligning film may also require a function of controlling the pretilt angle of the liquid crystal so that the liquid crystal forms a pretilt angle between the substrate and aligns.

On the other hand, the ability to control the alignment of the liquid crystal in the liquid crystal alignment film (hereinafter, referred to as alignment control ability) can be imparted by performing alignment treatment on the organic film constituting the liquid crystal alignment film.

As an alignment treatment of a liquid crystal alignment film that imparts alignment control ability, a rubbing method has been known conventionally. The rubbing method refers to an organic film such as polyvinyl alcohol, polyamide, or polyimide on a substrate, the surface of which is rubbed with a cloth such as cotton, nylon, or polyester in a certain direction (rubbed), and the rubbing direction (rubbing direction) It is a method of aligning the liquid crystal. This rubbing method has been used in a conventional liquid crystal display device manufacturing process because it can easily and achieve a relatively stable liquid crystal alignment state. In addition, as the organic film used for the liquid crystal alignment film, a polyimide-based organic film having excellent reliability, such as heat resistance, and electrical properties, has been selected and used.

However, in the rubbing method of rubbing the surface of the liquid crystal aligning film which is an organic film, there are cases in which oscillation and generation of static electricity become a problem. In addition, due to the recent high-definition of liquid crystal display devices and irregularities caused by electrodes on a corresponding substrate or switching active elements for liquid crystal driving, the surface of the liquid crystal alignment film cannot be uniformly rubbed with a cloth, and uniform liquid crystal alignment can be achieved. There was no case.

Therefore, as another alignment treatment method for a liquid crystal alignment film not subjected to rubbing, a photoalignment method is actively studied.

Although there are various methods for the photo-alignment method, anisotropy is formed in the organic film constituting the liquid crystal alignment film by linearly polarized light or collimated light, and the liquid crystal is aligned according to the anisotropy.

As the main photoalignment method, a decomposition type photoalignment method is known. For example, it is a method of irradiating a polyimide film with polarized ultraviolet rays, using the polarization direction dependence of the ultraviolet absorption of the molecular structure, causing anisotropic decomposition, and aligning the liquid crystal with the polyimide left without decomposition (e.g. For example, refer to Patent Document 1).

Moreover, photo-crosslinking type and photo-isomerization type photoalignment method are also known. For example, by irradiating polarized ultraviolet rays using polyvinyl cinnamate, causing a dimerization reaction (crosslinking reaction) at the double bond portion of two side chains parallel to the polarization, and aligning the liquid crystal in a direction orthogonal to the polarization direction. It is a method of making (see, for example, Non-Patent Document 1).

As in the above example, in the alignment treatment method of the liquid crystal alignment film by the photo-alignment method, rubbing is unnecessary, and there is no fear of oscillation or generation of static electricity. In addition, alignment treatment can be performed also on a substrate of a liquid crystal display element having irregularities on the surface, which is a method of alignment treatment of a liquid crystal alignment film suitable for an industrial production process.

However, also in the photo-alignment method, a peculiar problem by using light is pointed out.

That is, when linearly polarized light or collimated light is irradiated to an organic film on a substrate on which an electrode or the like is formed, the alignment treatment may be disturbed due to the influence of light reflection from the lower substrate or the like. Disruption of such alignment treatment lowers the display quality of the obtained liquid crystal display element.

Moreover, even after irradiation of light, an unreacted group may remain in a liquid crystal aligning film, and when a liquid crystal display element is manufactured using such a liquid crystal aligning film, the unreacted group reacts by the light of a short wavelength in a backlight or external light, and liquid crystal There is a problem that a defect occurs in that the orientation state of is changed.

Regarding the problem of light reflection in such a photoalignment method, for example, in Patent Document 2, on the lower layer side of the liquid crystal alignment film by the photoalignment method, for example, a short wavelength in reflected light from a substrate or backlight light A technique for further and further forming a resin layer for attenuating components is disclosed.

Japanese Patent No. 3893659 Specification Japanese Patent No. 4651677 Specification

M. Shadt et al., Jpn. J. Appl. Phys. 31, 2155 (1992)

However, forming an additional resin layer on the lower layer of the liquid crystal aligning film increases the manufacturing process of the liquid crystal display element compared to the conventional one. That is, there is a concern that the production method of the liquid crystal display element using the photo-alignment method is made more complicated than the conventional one, resulting in a decrease in productivity.

Therefore, in the manufacture of a liquid crystal display device using the photo-alignment method, a technology that enables the provision of a liquid crystal display device without complicating the manufacturing process and without alignment disturbance due to light reflection in accordance with the conventional manufacturing method Is being demanded.

The present invention has been made in view of the above points, and an object of the present invention is a liquid crystal aligning agent capable of producing a liquid crystal display device with reduced alignment disturbance without following a complicated manufacturing method, and formed from the liquid crystal aligning agent It is to provide a liquid crystal alignment film to be used, and further, a liquid crystal display element having the liquid crystal alignment film.

The present invention has the following summary.

1. A first polymer that reacts in light in a wavelength range of 250 to 380 nm, and

A liquid crystal aligning agent containing at least one of a compound having an absorption maximum in a wavelength range of 250 to 380 nm and a second polymer.

2. The liquid crystal aligning agent according to the above 1, wherein the content of at least one type of the compound and the second polymer is 3 to 80 mass% of the total content combined with the first polymer.

3. The first polymer has a photoreactive group that reacts to the light, and the photoreactive group is at least one structure selected from the group consisting of a cinnamoyl structure, a coumarin structure, and a chalcone structure. Orientation agent.

4. The liquid crystal aligning agent according to 3 above, wherein the photoreactive group contains any one of the following side chain structures.

[Formula 1]

(The broken line represents the binding group to the main chain of the polymer.

R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (however, any hydrogen atom may be substituted with a fluorine atom), or an alkoxyl group having 1 to 10 carbon atoms (however, the optional hydrogen atom is fluorine It may be substituted with an atom.) is shown.

A and B each independently represent a single bond or a ring structure represented by the following formula.

[Formula 2]

Each T independently represents a single bond, ether, ester, amide or ketone bond. S represents a single bond or an alkylene group having 1 to 10 carbon atoms.

However, when both S and A are single bonds, oxygen atoms are not adjacent.)

5. The liquid crystal aligning agent according to any one of the above 1 to 4, wherein the compound and the second polymer have a specific structure, and the specific structure is at least one of a phenone structure and a diphenylamine structure.

6. The liquid crystal aligning agent according to the above 5, wherein the specific structure is a structure of the following formula.

[Formula 3]

(R represents an alkyl group having 1 to 5 carbon atoms.)

7. The liquid crystal aligning agent according to any one of the above 1 to 6, wherein the first polymer is at least one polymer selected from the group consisting of a polyamic acid and a polyimide obtained by imidizing the polyamic acid.

8. In any one of the above 1 to 7, which contains the second polymer, wherein the second polymer is at least one polymer selected from the group consisting of polyamic acid and polyimide obtained by imidizing the polyamic acid. The described liquid crystal aligning agent.

9. A liquid crystal aligning film obtained by applying the liquid crystal aligning agent according to any one of the above 1 to 8, drying and firing.

10. The liquid crystal aligning film according to the above 9, wherein the firing temperature is 50 to 300°C.

11. The liquid crystal alignment film according to the above 9 or 10, wherein the film thickness after firing is 5 to 300 nm.

12. A liquid crystal display device comprising the liquid crystal alignment film according to any one of 9 to 11 above.

By using the liquid crystal aligning agent of the present invention, a liquid crystal aligning film capable of providing a liquid crystal display element with reduced alignment disturbance for production without following a complicated manufacturing method is formed, and the liquid crystal display element having the liquid crystal aligning film is lightweight, It is a thin display device with low power consumption, and is used as an element for a portable information terminal that displays a high-precision image.

1 is a graph showing a relationship between a film thickness of an alignment film of a liquid crystal cell and a pretilt angle.

The inventors of the present invention are concerned with the occurrence of light interference in the liquid crystal alignment film due to the influence of light reflection from the lower layer, such as a glass substrate or electrode, in the photo-alignment treatment of the liquid crystal alignment film, and the reflected light in the photo alignment treatment of the liquid crystal alignment film. It was confirmed that the resulting interference affects the provision of the alignment control ability to the liquid crystal alignment film, in particular, the performance of forming a pretilt angle. Specifically, in a liquid crystal display device, it was confirmed that there is a dependence on the film thickness of the liquid crystal alignment film with respect to the pretilt angle of the liquid crystal.

This dependence of the pretilt angle of the liquid crystal on the film thickness of the liquid crystal alignment film causes a difference in the pretilt angle in the plane of one liquid crystal display element to be manufactured and between a plurality of liquid crystal display elements, and furthermore, display quality. It was found that it was a cause of lowering.

Interference of light that is of concern in the liquid crystal alignment film at the time of photo-alignment treatment is, for example, as disclosed in Patent Document 2 described above, in the lower layer of the liquid crystal alignment film, between the layer reflecting the light and the reflected light. A method of separately forming the absorbing layer is effective.

However, newly forming the layer for light absorption increases the manufacturing process of the liquid crystal display element and makes it complicated as described above. That is, if a function capable of reducing the influence of reflected light can be imparted to the liquid crystal aligning film itself without forming a new layer for light absorption, it is an effective method in reducing light interference.

The inventors of the present invention further study to make the liquid crystal alignment film contain a material capable of attenuating the reflected light during the photo-alignment treatment, and in particular, to form a layer for attenuating the reflected light in the lower portion of the liquid crystal alignment film. , Found that it is effective in suppressing optical interference.

In addition, the layer for suppressing the interference of light in the liquid crystal alignment film is that it is possible to form a layer that suppresses light interference in the liquid crystal alignment film by using the phenomenon of layer separation of the polymer when forming the liquid crystal alignment film, which is usually a polymer. I figured it out. As a result, the present invention has been completed.

That is, when forming a polymeric liquid crystal alignment layer, a plurality of components are used to generate layer separation, and a layer of a component suitable for light alignment is formed mainly in the upper layer portion of the formed liquid crystal alignment layer, and is effective in absorbing light in the lower layer portion. To form a layer of ingredients.

The obtained liquid crystal alignment film is mainly subjected to photoalignment treatment using an upper layer portion, and effectively imparts liquid crystal alignment. On the other hand, in the lower layer portion of the liquid crystal alignment film, for example, the reflected light from the substrate or electrode is absorbed and attenuated to suppress the influence of the reflected light from reaching the upper layer. As a result, in the liquid crystal alignment film of the present invention, interference of light due to reflected light during the photo-alignment treatment is suppressed, preferred photo-alignment treatment is realized, and the dependence of the alignment film thickness in forming the pretilt angle of the liquid crystal can be reduced.

In addition, even if unreacted photoreactive groups may remain in the film after photo-alignment treatment, the liquid crystal alignment film of the present invention reacts by backlight light or short-wavelength light in external light after production of a liquid crystal display element. It is possible to reduce the occurrence of defects in which the orientation state of is changed.

As described above, the liquid crystal alignment film of the present invention utilizes layer separation in forming the alignment film. That is, without applying a special method, a liquid crystal alignment film having a desired structure can be formed in one step of forming a liquid crystal alignment film as in the prior art.

As disclosed in Patent Document 2, the liquid crystal alignment film of the present invention does not need to form a separate step of forming a layer for attenuating reflected light, and a method of manufacturing a liquid crystal display device having a liquid crystal alignment film by a photo-alignment method I don't have to do something complicated.

<Liquid crystal aligning agent>

The liquid crystal aligning agent of the present invention contains at least one of a first polymer reacting with light in a wavelength range of 250 to 380 nm, a compound having an absorption maximum in a wavelength range of 250 to 380 nm, and a second polymer.

By using the first polymer as a component, effective photoalignment treatment is enabled in the formed liquid crystal alignment film.

In addition, in the liquid crystal alignment film formed by using a compound and/or a second polymer having an absorption maximum in the wavelength range of 250 to 380 nm as a component, light from the lower layer side, for example, reflected light from a substrate, etc. It can be absorbed and attenuated, and the influence of reflected light and the like can be reduced in the photo-alignment treatment.

The content of the compound and/or the second polymer having an absorption maximum in the wavelength range of 250 to 380 nm contained in the liquid crystal aligning agent of the present invention is set to 3 to 80% by mass with respect to the total amount combined with the first polymer. It is preferable and 50-80 mass% is more preferable.

(First polymer reacting in light in the wavelength range of 250 to 380 nm)

The first polymer contains a group having at least one structure selected from the group consisting of a cinnamoyl structure, a coumarin structure, and a chalcone structure, which is a reactive group for light in a wavelength range of 250 to 380 nm, preferably 280 to 360 nm. It is desirable. Specifically, it is preferable that the photoreactive group of the first polymer contains any one of the following side chain structures.

[Formula 4]

In the above formula, a broken line represents a linking group to the main chain of the polymer.

R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (however, any hydrogen atom may be substituted with a fluorine atom), or an alkoxyl group having 1 to 10 carbon atoms (however, the optional hydrogen atom is fluorine It may be substituted with an atom.) is shown.

A and B each independently represent a single bond or a ring structure represented by the following formula.

[Formula 5]

Each T independently represents a single bond, ether, ester, amide or ketone bond. S represents a single bond or an alkylene group having 1 to 10 carbon atoms. However, when both S and A are single bonds, oxygen atoms are not adjacent.

The main chain of the first polymer is preferably at least one selected from the group consisting of hydrocarbon, polyimide, polyamic acid, acrylate, methacrylate, maleimide, α-methylene-γ-butyrolactone and siloxane.

The first polymer is particularly preferably at least one polymer selected from the group consisting of a polyamic acid and a polyimide obtained by imidizing the polyamic acid. By doing so, it is possible to form a highly reliable liquid crystal alignment film excellent in heat resistance and electrical properties.

Polyamic acid can usually be obtained by reaction of a diamine compound and tetracarboxylic dianhydride. Hereinafter, the diamine compound 1 and the tetracarboxylic dianhydride 1 which are preferable for the formation of polyamic acid and polyimide preferable as the first polymer will be described.

[Diamine compound 1]

As the diamine compound 1, not only one type, but multiple types can be selected and used, and it is preferable to use one or more diamine compounds having a photoreactive group reacting to light.

The photoreactive group of the diamine compound 1 is preferably a group that reacts with light in a wavelength range of 250 to 380 nm. As the photoreactive group, at least one group selected from the group consisting of a cinnamoyl structure, a coumarin structure, and a chalcone structure can be mentioned.

Specifically, it is preferable that the photoreactive group which the diamine compound has contains any one of the following side chain structures.

[Formula 6]

In the above formula, R is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (however, any hydrogen atom may be substituted with a fluorine atom.), or an alkoxyl group having 1 to 10 carbon atoms (however, the optional The hydrogen atom may be substituted with a fluorine atom).

A and B each independently represent a single bond or a ring structure represented by the following formula.

[Formula 7]

Each T independently represents a single bond, ether, ester, amide or ketone bond. S represents a single bond or an alkylene group having 1 to 10 carbon atoms. However, when both S and A are single bonds, oxygen atoms are not adjacent.

Below, a preferable example of the diamine compound which has a photoreactive group is shown.

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

[Formula 23]

[Formula 24]

[Formula 25]

[Formula 26]

In addition, in the C _n H _2n+1 portion of the diamine compound illustrated in each of the above formulas, n represents an integer of 1 to 18.

The liquid crystal aligning film of this invention can be made into the liquid crystal aligning film of vertical alignment.

The first polymer used for its formation is preferably at least one polymer selected from the group consisting of polyamic acid and polyimide obtained by imidizing the polyamic acid as described above, and the polyamic acid is It is preferably formed of a diamine component containing a chain diamine compound.

The above-described side chain type diamine compound is a diamine compound having at least one of an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocycle, and a large cyclic substituent composed of them in the side chain.

Specifically, the diamine compound represented by the following formulas [DA-1] to [DA-30] can be illustrated.

[Formula 27]

(R ₆ is an alkyl group or a fluorine-containing alkyl group having 1 to 22 carbon atoms.)

[Formula 28]

(A plurality of S ₅ is each independently -COO-, -OCO-, -CONH-, -NHCO-, -CH ₂ -, -O-, -CO-, or -NH-, and R ₆ is carbon number It is an alkyl group or a fluorine-containing alkyl group of 1 to 22.)

[Chemical Formula 29]

(S ₆ is -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -, or -CH ₂ OCO-, and R ₇ is an alkyl group, an alkoxy group, a fluorine-containing alkyl group having 1 to 22 carbon atoms, or It is a fluorine-containing alkoxy group.)

[Formula 30]

(S ₇ is -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ -, or -CH ₂ -, and R ₈ is an alkyl group, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group having 1 to 22 carbon atoms.)

[Formula 31]

(S ₈ is -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ -, -CH ₂ -, -O- , Or -NH-, and R ₉ is a fluorine group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, or a hydroxyl group.)

[Formula 32]

(R ₁₀ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomers of 1,4-cyclohexylene are trans forms, respectively.)

[Formula 33]

[Formula 34]

[Formula 35]

At the same time as the diamine compound having a photoreactive group described above, for the purpose of supplementing the vertical alignment ability, the diamine compound of the above formulas [DA-1] to [DA-30] can also be used in combination. As a more preferable diamine that can be used in combination, the formulas [DA-10] to [DA-30] are preferable, and more preferably the formulas [DA-10] to [DA-] from the points of voltage retention and residual accumulation voltage. It is a diamine compound of 16].

Although it does not specifically limit, preferable content of these diamine compounds is 5-50 mol% of the diamine component for forming a 1st polymer, More preferably, it is 5-30 mol%.

As the first polymer described above, in the diamine component suitable for formation of a preferable polyamic acid and polyimide, in addition to the diamine compound having a photoreactive group and the side chain diamine compound, other diamine compounds (other diamines It may be called a compound.) It is also possible to contain. Other diamine compounds are not particularly limited, but include alicyclic diamines, aromatic diamines, aromatic-aliphatic diamines, heterocyclic diamines, aliphatic diamines, and the like. The specific example is as follows.

Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'- Dimethyldicyclohexylamine, isophoronediamine, etc. are mentioned.

Examples of aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 3,5-diaminotoluene, 1, 4-diamino-2-methoxybenzene, 2,5-diamino-p-xylene, 1,3-diamino-4-chlorobenzene, 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'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'- Diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobenzophenone, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-amino Phenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 3,5-bis(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-amino Phenoxy)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)hexafluoro Lopropane, 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-dio 8, di(4-aminophenyl)butane-1,4-dioate, di(4-aminophenyl)pentane-1,5-dioate, di(4-aminophenyl)hexane-1,6-dioate, Di(4-aminophenyl)heptane-1,7-dioate, di(4-aminophenyl)octane-1,8-dioate, di(4-aminophenyl)nonane-1,9-dioate, di( 4-aminophenyl)decane-1,10-dioate, 1,3-bis[4-(4-aminophenoxy)phenoxy]propane, 1,4-bis[4-(4-aminophenoxy)phenoxy Si]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 Cy]nonane, 1,10-bis[4-(4-aminophenoxy)phenoxy]decane, and the like.

Examples of aromatic-aliphatic diamines include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, 3-aminophenethylamine, and 4-amino Phenylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methylphenethylamine, 3-(3-aminopropyl)aniline, 4-(3-aminopropyl)aniline, 3-(3 -Methylaminopropyl)aniline, 4-(3-methylaminopropyl)aniline, 3-(4-aminobutyl)aniline, 4-(4-aminobutyl)aniline, 3-(4-methylaminobutyl)aniline, 4 -(4-methylaminobutyl)aniline, 3-(5-aminopentyl)aniline, 4-(5-aminopentyl)aniline, 3-(5-methylaminopentyl)aniline, 4-(5-methylaminopentyl) Aniline, 2-(6-aminonaphthyl)methylamine, 3-(6-aminonaphthyl)methylamine, 2-(6-aminonaphthyl)ethylamine, 3-(6-aminonaphthyl)ethylamine, etc. Can be mentioned.

Examples of heterocyclic diamines include 2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5-triazine, 2,7-diaminodibenzofuran, 3,6-diaminocarbazole, 2,4-diamino-6-isopropyl-1,3,5-triazine, 2,5-bis(4-aminophenyl)-1,3,4-oxadia Sol, etc. are mentioned.

Examples of aliphatic diamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7- Diaminoheptane, 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.

(Tetracarboxylic dianhydride 1)

The diamine compound mentioned above and the tetracarboxylic dianhydride made to react in order to obtain the polyamic acid preferable as a 1st polymer are not specifically limited. The specific example is given below.

As tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetra Carboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane Tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,2,4,5- Cyclohexanetetracarboxylic dianhydride, 3,4-dicarboxy-1-cyclohexylsuccinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride, 1 ,2,3,4-butanetetracarboxylic dianhydride, bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride, 3,3',4,4' -Dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6- Tetracarboxylic dianhydride, tricyclo[4.2.1.0 ^2,5 ] nonane-3,4,7,8-tetracarboxylic acid-3,4:7,8-2 anhydride, hexacyclo[6.6.0.1 ^{2 , 7.0, 3,6} .1 ^9,14 .0 ^10,13] hexadecane -4,5,11,12- tetracarboxylic acid 4,5: 11,12-2 anhydride, 4- (2, 5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, and the like.

As aromatic tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid Dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3,3',4-benzo Phenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid 2 Anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, etc. are mentioned.

In addition to the above-described tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure, the use of an aromatic tetracarboxylic dianhydride is preferable because the liquid crystal orientation improves and the accumulated charge of the liquid crystal cell can be reduced. .

Tetracarboxylic dianhydride can be used singly or in combination of two or more depending on characteristics such as liquid crystal alignment, voltage retention characteristics, and accumulated charge of the formed liquid crystal alignment film.

〔Polyamic acid 1〕

The polyamic acid preferable as a 1st polymer can be obtained by reaction of the tetracarboxylic dianhydride mentioned above and the diamine component which consists of the above-mentioned diamine compound.

As a method of obtaining the polyamic acid as the first polymer, a known synthetic method can be used. In general, it is a method of reacting a tetracarboxylic dianhydride and a diamine component in an organic solvent.

The reaction of the tetracarboxylic dianhydride and the diamine compound is advantageous in that the reaction proceeds relatively easily in an organic solvent and no by-products are generated.

The organic solvent used for the reaction of the tetracarboxylic dianhydride and the diamine compound is not particularly limited as long as the resulting polyamic acid is dissolved. The specific example is given below.

N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, Pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl Ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol mono Butyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene Glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl- 3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diiso Butyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, acetic acid Methyl, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid , 3-methoxypropionic acid, 3-methoxypropionic acid propyl, 3-methoxy butyl propionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropanamide , 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropana Mid, etc. are mentioned.

These organic solvents may be used alone or may be used in combination. Moreover, even if it is a solvent which does not dissolve the polyamic acid, you may use it, mixing with the above-mentioned organic solvent within the range in which the produced|generated polyamic acid does not precipitate.

Since moisture in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the resulting polyamic acid, the organic solvent used is preferably dehydrated and dried to the extent possible.

When reacting tetracarboxylic dianhydride and diamine component in an organic solvent, a solution obtained by dispersing or dissolving the diamine component in an organic solvent is stirred, and tetracarboxylic dianhydride is added as it is or dispersed or dissolved in an organic solvent. And, on the contrary, a method of adding a diamine component to a solution in which tetracarboxylic dianhydride is dispersed or dissolved in an organic solvent, a method of alternately adding a tetracarboxylic dianhydride and a diamine component, and the like. You may use either method. In addition, when the tetracarboxylic dianhydride or diamine component is made of a plurality of compounds, the reaction may be carried out in a premixed state, or may be individually sequentially reacted, or the individually reacted low molecular weight compounds are mixed and reacted to produce a high molecular weight compound. You may do it.

The polymerization temperature can select any temperature of -20 to 150°C, but is preferably in the range of -5 to 100°C.

In addition, the reaction can be carried out at an arbitrary concentration, but if the concentration is too low, it becomes difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring becomes difficult. The total concentration in the reaction solution of the acid dianhydride and the diamine component is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial reaction is carried out at a high concentration, and then, an organic solvent can be added.

In the polymerization reaction described above, the ratio of the total number of moles of tetracarboxylic dianhydride and the total number of moles of diamine component is preferably from 0.8 to 1.2, and more preferably from 0.9 to 1.1. Similar to the normal polycondensation reaction, the molecular weight of the resulting polyamic acid increases as the molar ratio is closer to 1.0.

[Polyimide 1]

A polyimide preferable as the first polymer can be obtained by dehydrating and ring-closing (imidizing) the polyamic acid described above.

As a preferable polyimide, the dehydration cyclization rate (imidation rate) of an amic acid group does not necessarily need to be 100%, and can be arbitrarily adjusted so that it may be 100% or less depending on the use and purpose.

As a method of imidizing the polyamic acid, thermal imidation in which the solution of polyamic acid is heated as it is, and catalyst imidization in which a catalyst is added to the solution of polyamic acid are exemplified.

When the polyamic acid is thermally imidized in a solution, the temperature is 100 to 400°C, preferably 120 to 250°C, and a method performed while removing water generated by the imidation reaction outside the system is preferable.

The catalytic imidization of the polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to the solution of the polyamic acid and stirring at -20 to 250°C, preferably 0 to 180°C.

The amount of the basic catalyst is 0.5 to 30 mole times, preferably 2 to 20 mole times of the amic acid group, and the amount of the acid anhydride is 1 to 50 mole times, preferably 3 to 30 mole times of the amic acid group.

Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and the like. Among them, pyridine is preferable because it has a suitable basicity to advance the reaction.

Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, acetic anhydride is preferably used because purification after completion of the reaction becomes easy.

The imidation rate by catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[Polyamic acid ester]

As the 1st polymer which becomes the component of the liquid crystal aligning agent of this invention, it is also possible to use polyamic acid ester and polyamide in addition to the polyamic acid and polyimide mentioned above.

As a method of synthesizing a preferable polyamic acid ester, a reaction of a tetracarboxylic acid diester dichloride and the above-described preferable diamine compound, or a tetracarboxylic acid diester and the above-described preferable diamine compound in the presence of a condensing agent, a base, etc., There is a way to react. By these methods, a polyamic acid ester, which is a kind of polyimide precursor, can be obtained.

Moreover, polyamic acid ester can also be obtained by esterifying the carboxylic acid in the amic acid using a polymer reaction with the polyamic acid which was polymerized beforehand.

Specifically, tetracarboxylic acid diester dichloride and the above-described preferred diamine compound are used in the presence of a base and an organic solvent at -20 to 150°C, preferably 0 to 50°C, for 30 minutes to 24 hours, preferably It can be synthesized by reacting for 1 to 4 hours.

As the base, pyridine, triethylamine, 4-dimethylaminopyridine, or the like can be used, but pyridine is preferable in order to proceed gently. The addition amount of the base is an amount that is easily removed, and is preferably 2 to 4 mole times, and more preferably 2.5 to 3.5 mole times with respect to tetracarboxylic acid diester dichloride.

When carrying out the condensation polymerization reaction in the presence of a condensing agent, examples of the condensing agent include triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N,N '-Carbonyldiimidazole, dimethoxy-1,3,5-triazinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium Tetrafluoroborate, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluroniumhexafluorophosphite, (2,3-dihydro-2-thioxo- 3-benzoxazolyl)phosphonic acid diphenyl, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)4-methoxymorpholinium chloride n-hydrate, etc. can be used. .

Moreover, in the method of using a condensing agent, when Lewis acid is added as an additive, the reaction proceeds efficiently. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The amount of Lewis acid added is preferably 0.1 to 1.0 mole times, and more preferably 0.5 to 1.0 mole times with respect to the tetracarboxylic acid diester.

As the organic solvent, an organic solvent used when the above-described tetracarboxylic dianhydride and a preferred diamine component are polymerized to obtain a polyamic acid can be used, but from the solubility of the monomer and the resulting polymer, N-methyl-2-pi Use of rolidone, γ-butyrolactone, or the like is preferred. These solvents may be used alone or in combination of two or more. Moreover, in order to prevent hydrolysis of tetracarboxylic acid diester dichloride, it is preferable that the organic solvent used for synthesis of a polyamic acid ester is dehydrated as much as possible.

The total concentration in the reaction solution of the tetracarboxylic acid diester dichloride and the diamine component is preferably 1 to 30% by mass, and 5 to 20% by mass from the viewpoint that precipitation of the polymer is difficult to occur and the high molecular weight is easily obtained. Is more preferable.

In addition, the reaction is preferably carried out in a nitrogen atmosphere to prevent mixing of outside air.

[Polyamide]

A polyamide preferable as the first polymer described above can also be synthesized in the same manner as the polyamic acid ester described above.

[Recovery of polymer]

When recovering the resulting polyamic acid and polyimide from a reaction solution such as polyamic acid and polyimide, the reaction solution may be introduced into a poor solvent to precipitate the polymer. Examples of poor solvents used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water.

After the precipitated polymer is collected by filtration, it can be dried at room temperature or heated under normal pressure or reduced pressure. Moreover, if the polymer recovered by precipitation is re-dissolved in an organic solvent and the operation of reprecipitation recovery is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons, and the like. When three or more types of poor solvents selected from these are used, the purification efficiency is further improved, and thus, it is preferable.

The molecular weight of the polyamic acid and/or polyimide contained as the first polymer is the weight measured by the GPC (Gel Permeation Chromatography) method when considering the strength of the resulting coating film, workability at the time of forming the coating film, and the uniformity of the coating film. The average molecular weight is preferably from 2000 to 1000000, more preferably from 5000 to 100000.

[Compound and second polymer having an absorption maximum in the wavelength range of 250 to 380 nm]

These compounds and the second polymer have a wavelength range of 250 to 380 nm, preferably at least selected from the group consisting of a cinnamoyl structure, a phenone structure, and a diphenylamine structure having an absorption maximum for light of 280 to 360 nm. It is preferable to have one type of specific structure, and in particular, it is more preferable to have at least one type of specific structure among a phenone structure and a diphenylamine structure. In addition, in the present invention, having an absorption maximum means having a maximum absorption wavelength in the range of 250 to 380 nm when the UV-vis spectrum of the monomer used in the polymer of the present invention or itself is measured. will be.

As a specific example of the said specific structure, it is preferable that it is a compound shown below.

[Formula 36]

(R represents an alkyl group having 1 to 5 carbon atoms.)

In particular, as a preferred second polymer, it is preferred that it is at least one polymer selected from the group consisting of polyamic acid and a polyimide obtained by imidizing the polyamic acid. By doing so, it is possible to form a highly reliable liquid crystal alignment film excellent in heat resistance and electrical properties.

As described above, the polyamic acid can usually be obtained by reaction of a diamine compound and tetracarboxylic dianhydride.

Hereinafter, the diamine compound and tetracarboxylic dianhydride which can be used for the formation of the preferred polyamic acid and polyimide as the second polymer will be described.

[Diamine compound 2]

As the second polymer, the diamine compound that can be used for the formation of preferable polyamic acid and polyimide is not particularly limited, but alicyclic diamines, aromatic diamines, aromatic-aliphatic diamines, heterocyclic diamines, aliphatic diamines Etc. are mentioned. These diamines are selected and used in combination so as to form a polymer having an absorption maximum in a wavelength range of 250 to 380 nm by reaction with a tetracarboxylic dianhydride described later. The specific example of the diamine compound which can be used is as follows.

Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'- Dimethyldicyclohexylamine, isophoronediamine, etc. are mentioned.

Examples of aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 3,5-diaminotoluene, 1, 4-diamino-2-methoxybenzene, 2,5-diamino-p-xylene, 1,3-diamino-4-chlorobenzene, 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'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'- Diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobenzophenone, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-amino Phenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 3,5-bis(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-amino Phenoxy)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)hexafluoro Lopropane, 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-dio 8, di(4-aminophenyl)butane-1,4-dioate, di(4-aminophenyl)pentane-1,5-dioate, di(4-aminophenyl)hexane-1,6-dioate, Di(4-aminophenyl)heptane-1,7-dioate, di(4-aminophenyl)octane-1,8-dioate, di(4-aminophenyl)nonane-1,9-dioate, di( 4-aminophenyl)decane-1,10-dioate, 1,3-bis[4-(4-aminophenoxy)phenoxy]propane, 1,4-bis[4-(4-aminophenoxy)phenoxy Si]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 Cy]nonane, 1,10-bis[4-(4-aminophenoxy)phenoxy]decane, and the like.

Examples of aromatic-aliphatic diamines include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, 3-aminophenethylamine, and 4-amino Phenylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methylphenethylamine, 3-(3-aminopropyl)aniline, 4-(3-aminopropyl)aniline, 3-(3 -Methylaminopropyl)aniline, 4-(3-methylaminopropyl)aniline, 3-(4-aminobutyl)aniline, 4-(4-aminobutyl)aniline, 3-(4-methylaminobutyl)aniline, 4 -(4-methylaminobutyl)aniline, 3-(5-aminopentyl)aniline, 4-(5-aminopentyl)aniline, 3-(5-methylaminopentyl)aniline, 4-(5-methylaminopentyl) Aniline, 2-(6-aminonaphthyl)methylamine, 3-(6-aminonaphthyl)methylamine, 2-(6-aminonaphthyl)ethylamine, 3-(6-aminonaphthyl)ethylamine, etc. Can be mentioned.

Examples of heterocyclic diamines include 2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5-triazine, 2,7-diaminodibenzofuran, 3,6-diaminocarbazole, 2,4-diamino-6-isopropyl-1,3,5-triazine, 2,5-bis(4-aminophenyl)-1,3,4-oxadia Sol, etc. are mentioned.

Examples of aliphatic diamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7- Diaminoheptane, 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 the above diamine compounds, it is particularly preferable to select 4,4'-diaminodiphenylamine and/or 4,4'-diaminobenzophenone to use for the formation of polyamic acid and polyimide. This is because the formed polyamic acid and polyimide can have a higher absorption maximum in the wavelength range of 250 to 380 nm.

(Tetracarboxylic dianhydride 2)

The tetracarboxylic dianhydride which can be used for formation of a polyamic acid and a polyimide preferable as a 2nd polymer is not specifically limited. The combination is selected and used so as to form a polymer having an absorption maximum in a wavelength range of 250 to 380 nm by reaction with the above-described diamine compound. The specific example of the usable tetracarboxylic dianhydride is as follows.

As tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetra Carboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane Tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,2,4,5- Cyclohexanetetracarboxylic dianhydride, 3,4-dicarboxy-1-cyclohexylsuccinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride, 1 ,2,3,4-butanetetracarboxylic dianhydride, bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride, 3,3',4,4' -Dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6- Tetracarboxylic dianhydride, tricyclo[4.2.1.0 ^2,5 ] nonane-3,4,7,8-tetracarboxylic acid-3,4:7,8-2 anhydride, hexacyclo[6.6.0.1 ^{2 , 7.0, 3,6} .1 ^9,14 .0 ^10,13] hexadecane -4,5,11,12- tetracarboxylic acid 4,5: 11,12-2 anhydride, 4- (2, 5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, and the like.

As aromatic tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid Dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3,3',4-benzo Phenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid 2 Anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, etc. are mentioned.

When aromatic tetracarboxylic dianhydride is used in addition to tetracarboxylic dianhydride having an alicyclic structure or aliphatic structure described above, the liquid crystal alignment of the liquid crystal alignment film made of the polymer to be formed is improved, and the accumulation of liquid crystal cells It is preferable because electric charges can be reduced.

Among the above-described tetracarboxylic dianhydrides, in particular, pyromellitic dianhydride and/or 3,3',4,4'-benzophenonetetracarboxylic dianhydride are selected for the formation of polyamic acid and polyimide. It is preferable to use. This is because the formed polyamic acid and polyimide can have a higher absorption maximum in the wavelength range of 250 to 380 nm.

(Polyamic acid 2 and polyimide 2)

The polyamic acid preferable as a 2nd polymer can be obtained by reaction of the tetracarboxylic dianhydride mentioned above and the diamine component which consists of the above-mentioned diamine compound.

As a method of obtaining the polyamic acid as the second polymer, a known synthetic method can be used. For example, as the first polymer described above, it can be obtained by the same method as described as a method of obtaining a preferable polyamic acid.

Moreover, a polyimide preferable as a 2nd polymer can be obtained by subjecting the obtained polyamic acid to dehydration ring closure (imidization). Specifically, as the first polymer described above, it can be obtained by the same method as described as a method of obtaining a preferable polyimide.

In the polyimide preferred as the second polymer, the dehydration cyclization rate (imidation rate) of the amic acid group is not necessarily 100%, and can be arbitrarily adjusted so as to be 100% or less depending on the use or purpose.

The molecular weight of the polyamic acid and/or polyimide contained as the second polymer is the weight measured by GPC (Gel Permeation Chromatography) method when considering the strength of the resulting coating film, workability at the time of forming the coating film, and the uniformity of the coating film. The average molecular weight is preferably from 2000 to 1000000, more preferably from 5000 to 100000.

As a compound having an absorption maximum in a wavelength range of 250 to 380 nm, which is another component of the liquid crystal aligning agent of the present invention, a diamine compound and tetracarboxylic dianhydride considered preferable for formation of the second polymer described above It is preferable to use. More specifically, examples of the diamine compound include 4,4'-diaminodiphenylamine, 4,4'-diaminobenzophenone, and the like. Moreover, as tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, etc. are mentioned.

[Preparation of liquid crystal aligning agent]

As described above, the liquid crystal aligning agent of the present invention is at least among a first polymer reacting in light in a wavelength range of 250 to 380 nm, a compound having an absorption maximum in a wavelength range of 250 to 380 nm, and a second polymer. Consists of 1 species. It is preferable that the said liquid crystal aligning agent is prepared as a coating liquid so that it may become suitable for formation of a liquid crystal aligning film.

That is, it is preferable that the liquid crystal aligning agent of this invention is prepared as a solution in which a resin component for forming a resin film was dissolved in an organic solvent. Here, the resin component is a resin component containing a first polymer, a second polymer, and the like described above.

The content of the resin component is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and particularly preferably 3 to 10% by mass with respect to the total amount (100% by mass) of the liquid crystal aligning agent.

In the liquid crystal aligning agent, all of the resin components described above may be a first polymer, or a first polymer and a second polymer may be used, but other polymers other than these may be mixed. In that case, the content of the other polymer in the resin component is 0.5 to 15% by mass, preferably 1 to 10% by mass.

As another polymer, for example, a polymer consisting of polyamic acid, polyimide, etc., which does not react in light in the wavelength range of 250 to 380 nm, and does not have an absorption maximum in the wavelength range of 250 to 380 nm Etc. are mentioned.

The organic solvent used for a liquid crystal aligning agent is not specifically limited if it is an organic solvent which dissolves a resin component. The specific example is given below.

N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrroli Don, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropane Amide, 3-butoxy-N,N-dimethylpropanamide, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclo Hexanone, ethylene carbonate, propylene carbonate, diglyme, 4-hydroxy-4-methyl-2-pentanone, and the like. These may be used alone or may be used in combination.

The liquid crystal aligning agent of this invention may contain components other than the said component, such as a 1st polymer. Examples thereof include a solvent or compound that improves film thickness uniformity and surface smoothness when a liquid crystal aligning agent is applied, and a compound that improves adhesion between a liquid crystal aligning film and a substrate.

The following are mentioned as a specific example of the solvent (poor solvent) which improves the uniformity of a film thickness and surface smoothness.

For example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl Carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol Monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl Ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, Ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1-hexanol, n-hexane, n-pentane, n -Octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate Ethyl, 3-methoxy ethylpropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl, 3-methoxy butyl propionate, 1-methoxy-2-propanol, 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-mono Ethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester, etc. Solvents with low surface tension Can be heard.

These poor solvents may be used alone or in combination of plural types.

In the case of using a poor solvent, it is preferably 5 to 80% by mass, more preferably 20 to 60% by mass, of the entire solvent so that the solubility of the entire solvent contained in the liquid crystal aligning agent is not significantly reduced. .

As a compound which improves the uniformity of film thickness and surface smoothness, a fluorine-type surfactant, a silicone-type surfactant, a nonionic surfactant, etc. are mentioned.

Specifically, for example, FTOP (registered trademark) 301, EF303, EF352 (above, manufactured by Tochem Products), Megapack (registered trademark) F171, F173, R-30 (above, manufactured by DIC), fluorine Rod FC430, FC431 (above, manufactured by Sumitomo 3M), Asahigard (registered trademark) AG710 (manufactured by Asahi Glass), Suflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (or , AGC Seimi Chemical Co., Ltd.), etc. are mentioned. The ratio of use of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the resin component contained in the liquid crystal aligning agent.

As a specific example of the compound which improves the adhesiveness of a liquid crystal aligning film and a board|substrate, a functional silane-containing compound, an epoxy group-containing compound, etc. shown below are mentioned.

For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3 -Aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidepropyltrimethoxysilane, 3-ureidepropyltriethoxysilane, N-ethoxy Carbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetri Amine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl Acetate, 9-triethoxysilyl-3,6-diazanonylacetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3- Aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltri Ethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol di Glycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetragly Cidyl-2,4-hexanediol, N,N,N',N',-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclo Hexane, N,N,N',N',-tetraglycidyl-4,4'-diaminodiphenylmethane, etc. are mentioned.

In addition, in addition to improving the adhesion between the substrate and the liquid crystal aligning film, the following phenoplast additives are added to the liquid crystal aligning agent for the purpose of preventing a decrease in electrical properties due to the backlight when the liquid crystal display element is formed. You may contain it. Specific phenoplast additives are shown below, but are not limited to this structure.

[Formula 37]

When using a compound that improves adhesion to a substrate, the amount used is preferably 0.1 to 30 parts by mass, and more preferably 1 to 20 parts by mass based on 100 parts by mass of the resin component contained in the liquid crystal aligning agent. . When the amount is less than 0.1 parts by mass, the effect of improving the adhesion cannot be expected, and when the amount is more than 30 parts by mass, the alignment of the liquid crystal may be deteriorated.

In the liquid crystal aligning agent of the present invention, in addition to those described above, for the purpose of changing electrical properties such as dielectric constant and conductivity of the liquid crystal aligning film, as long as the effect of the present invention is not impaired, dielectric material, conductive material, and furthermore, liquid crystal A crosslinkable compound may be added for the purpose of increasing the hardness and density of the film when used as an alignment film.

<Liquid crystal alignment film and liquid crystal display element>

The liquid crystal aligning agent of the present invention is applied on a substrate and fired, similarly to the liquid crystal aligning agent for forming a liquid crystal aligning film made of polyimide, without applying any other method. A liquid crystal alignment film can be formed. Moreover, by performing photo-alignment treatment by light irradiation, an orientation control ability can be provided and can be used for manufacture of a liquid crystal display element.

As a substrate used when forming a liquid crystal aligning film by applying a liquid crystal aligning agent, when the liquid crystal display element to be manufactured is a transmission type, it is preferable to use a substrate having high transparency. In that case, there is no particular limitation, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used. In addition, for liquid crystal drive in a liquid crystal display element, it is preferable to use a substrate on which a transparent electrode such as an ITO (Indium Tin Oxide: indium tin oxide) electrode is formed from the viewpoint of simplification of the manufacturing process. In addition, in a reflective liquid crystal display device, as long as only one substrate is used, an opaque material such as a silicon wafer can be used, and the electrode in this case can be made of a material that reflects light such as aluminum.

In formation of the liquid crystal aligning film of this invention, the application method of a liquid crystal aligning agent is not specifically limited. As a coating method of the liquid crystal aligning agent, industrially, screen printing, offset printing, flexo printing, inkjet, and the like are common. As other coating methods, there are methods of using dips, roll coaters, slit coaters, spinners, and the like, and may be used depending on the purpose.

The sintering after applying the liquid crystal aligning agent on the substrate is carried out by heating means such as a hot plate at 50 to 300°C, preferably at 80 to 250°C for 1 to 200 minutes, preferably 10 to 100 minutes, For example, a coating film can be formed by evaporating a solvent which is an organic solvent.

If the thickness of the coating film formed after firing is too thick, when it is used for a liquid crystal display element, it is disadvantageous in terms of its power consumption, and if it is too thin, the reliability of the liquid crystal display element may decrease. Therefore, the thickness of the coating film after firing is preferably 5 to 300 nm, more preferably 10 to 100 nm.

When the liquid crystal is horizontally aligned or obliquely aligned, the coated film after firing is treated by polarized ultraviolet irradiation. That is, photo-alignment treatment is performed by light irradiation.

In addition, the liquid crystal alignment film of the present invention is capable of imparting alignment control ability, particularly, formation of a pretilt angle by rubbing treatment.

In the liquid crystal display device of the present invention, after obtaining a substrate with a liquid crystal alignment film on which a liquid crystal alignment film was formed from the liquid crystal aligning agent of the present invention by the method described above, a liquid crystal cell was produced by a known method, I did it. For example, a liquid crystal display device in a vertical alignment (VA) mode can be provided.

To give an example of the production of a liquid crystal cell, a pair of substrates on which the liquid crystal alignment film of the present invention is formed is prepared, a spacer is sprayed on the liquid crystal alignment film of one substrate, and the liquid crystal alignment film surface is inside, and the other substrate is A method of bonding and sealing by injecting a liquid crystal under reduced pressure, or a method of bonding and sealing a substrate after dropping the liquid crystal onto the liquid crystal alignment film surface sprayed with a spacer, and the like can be illustrated. The diameter of the spacer at this time is preferably 1 to 30 µm, more preferably 2 to 10 µm. This spacer diameter determines the distance between a pair of substrates that sandwich the liquid crystal layer, that is, the thickness of the liquid crystal layer.

As described above, the liquid crystal display element produced by using the liquid crystal aligning agent of the present invention has excellent reliability, and can be preferably used for a high-precision liquid crystal television with a large screen.

Example

Hereinafter, although an Example is given and this invention is demonstrated in more detail, this invention is limited to these and is not interpreted.

The symbols and structures of the main compounds used in Examples and Comparative Examples are as follows.

(Tetracarboxylic dianhydride)

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

PMDA ： Pyromellitic anhydride

BODA: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride

(Diamine)

m-PDA: m-phenylenediamine

PCH: 1,3-diamino-4-[4-(4-heptylcyclohexyl)phenoxy]benzene

DAM-1: (E)-2,4-diaminophenethyl 3-(4-(4-heptylcyclohexyl)phenyl)acrylate

[Formula 38]

DAM-2: N1-(4-aminophenyl)benzene-1,4-diamine

[Formula 39]

DAM-3: N1-(4-aminophenyl)-N1-methylbenzene-1,4-diamine

[Formula 40]

DAM-4: 4,4'-diaminobenzophenone

[Formula 41]

DAM-5: 4,4'-oxydianiline

[Formula 42]

DAM-6: 3,5-diaminobenzoic acid

[Formula 43]

DAM-7: 2,4-diaminophenethylcinnamate

[Formula 44]

(Organic solvent)

NMP: N-methyl-2-pyrrolidone

BCS ： Butyl Cellosolve

[Molecular weight measurement]

The molecular weight of the polyimide in the synthesis example is measured as follows using a normal temperature gel permeation chromatography (GPC) apparatus (SSC-7200) manufactured by Senshu Scientific Co., Ltd. and a column (KD-803, KD-805) manufactured by Shodex did.

Column temperature: 50 °C

Eluent: N,N'-dimethylformamide (as an additive, lithium bromide-hydrate (LiBr H ₂ O) is 30 mmol/L (liter), phosphoric acid anhydrous crystal (o-phosphoric acid) is 30 mmol/L, tetra Hydrofuran (THF) is 10 ml/l)

Flow rate: 1.0 ml/min

Standard samples for calibration curve preparation: TSK standard polyethylene oxide (molecular weight: about 9000000, 150000, 100000, and 30000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weight: about 12000, 4000, and 1000) manufactured by Polymer Laboratories.

<Synthesis Example 1>

CBDA (2.499 g, 12.74 mmol), and DAM-1 (6.015 g, 13.0 mmol) were mixed in NMP (48.24 g) and reacted at room temperature for 20 hours to obtain a polyamic acid solution. To this polyamic acid solution, NMP (42.57 g) and BC (42.57 g) were added, diluted to 6% by mass, and stirred at room temperature for 5 hours to obtain a polyamic acid solution (A1). The number average molecular weight of the polyamic acid contained was 9000, and the weight average molecular weight was 28000. In addition, the obtained polyamic acid solution (A1) can form a vertically aligned liquid crystal aligning film, can be used as a liquid crystal aligning agent, and is used as a liquid crystal aligning agent (A1) in Comparative Example 1 described later.

<Synthesis Example 2>

BODA (1.626 g, 6.24 mmol), and DAM-1 (6.015 g, 13.0 mmol) were mixed in NMP (37.68 g) and reacted at 80° C. for 5 hours, then CBDA (1.224 g, 6.24 mmol) and NMP ( 12.56 g) was added and reacted at 40° C. for 10 hours to obtain a polyamic acid solution. After NMP was added to this polyamic acid solution (58.0 g) and diluted to 6% by mass, acetic anhydride (3.91 g) and pyridine (2.02 g) were added as an imidation catalyst, and reacted at 50°C for 3 hours. This reaction solution was poured into methanol (530 ml), and the obtained precipitate was separated by filtration. Methanol wash|cleaned this deposit, it dried under reduced pressure at 100 degreeC, and obtained polyimide powder (B). The imidation ratio of this polyimide was 50 %, the number average molecular weight was 11000, and the weight average molecular weight was 31000.

NMP (29.3 g) was added to the obtained polyimide powder (B) (6.0 g), and it stirred and dissolved at 70 degreeC for 5 hours. A polyimide solution (B1) was obtained by adding and stirring NMP (34.7 g) and BC (30.0 g) to this solution. In addition, the obtained polyimide solution (B1) can form a vertically aligned liquid crystal aligning film, can be used as a liquid crystal aligning agent, and is used as a liquid crystal aligning agent (B1) in Comparative Example 2 described later.

<Synthesis Example 3>

CBDA (2.447 g, 12.48 mmol), and DAM-2 (2.59 g, 13.0 mmol) were mixed in NMP (28.55 g) and reacted at room temperature for 20 hours to obtain a polyamic acid solution. A polyamic acid solution (C1) was obtained by adding NMP (25.19 g) and BC (25.19 g) to this polyamic acid solution, diluting to 6% by mass, and stirring at room temperature for 5 hours. The number average molecular weight of the polyamic acid contained was 8700, and the weight average molecular weight was 18000.

Next, the polyamic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and this polyamic acid solution (C1) (8.0 g) were mixed at room temperature for 3 hours to allow formation of a vertically aligned liquid crystal alignment film. Article (C2) was prepared.

Moreover, the polyimide solution (B1) (2.0 g) obtained in Synthesis Example 2 and this polyamic acid solution (C1) (8.0 g) are mixed at room temperature for 3 hours, and a liquid crystal aligning agent capable of forming a vertically aligned liquid crystal aligning film (C3) was prepared.

<Synthesis Example 4>

CBDA (2.447 g, 12.48 mmol), and DAM-3 (2.773 g, 13.0 mmol) were mixed in NMP (29.58 g) and reacted at room temperature for 20 hours to obtain a polyamic acid solution. To this polyamic acid solution, NMP (26.1 g) and BC (26.1 g) were added, diluted to 6% by mass, and stirred at room temperature for 5 hours to obtain a polyamic acid solution (D1). The number average molecular weight of the polyamic acid contained was 9100, and the weight average molecular weight was 19000.

Next, the polyamic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and this polyamic acid solution (D1) (8.0 g) were mixed at room temperature for 3 hours, and a liquid crystal aligning agent capable of forming a vertically aligned liquid crystal alignment film (D2) was prepared.

<Synthesis Example 5>

CBDA (2.447 g, 12.48 mmol) and DAM-4 (2.759 g, 13.0 mmol) were mixed in NMP (29.5 g) and reacted at room temperature for 20 hours to obtain a polyamic acid solution. To this polyamic acid solution, NMP (26.0 g) and BC (26.0 g) were added, diluted to 6% by mass, and stirred at room temperature for 5 hours to obtain a polyamic acid solution (E1). The number average molecular weight of the polyamic acid contained was 10500, and the weight average molecular weight was 26000.

Next, the polyamic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and this polyamic acid solution (E1) (8.0 g) were mixed at room temperature for 3 hours, and a liquid crystal aligning agent capable of forming a vertically aligned liquid crystal alignment film (E2) was prepared.

<Synthesis Example 6>

CBDA (2.498 g, 12.74 mmol) and DAM-7 (3.670 g, 13.0 mmol) were mixed in NMP (34.96 g) and reacted at room temperature for 20 hours to obtain a polyamic acid solution. NMP (30.84 g) and BC (30.84 g) were added to this polyamic acid solution, diluted to 6% by mass, and stirred at room temperature for 5 hours to obtain a polyamic acid solution (F1). The number average molecular weight of the polyamic acid contained was 10800, and the weight average molecular weight was 23000.

Next, the liquid crystal aligning agent (A1) (2.0 g) obtained in Synthesis Example 1 and the polyamic acid solution (F1) (8.0 g) were mixed for 3 hours at room temperature, and the liquid crystal aligning agent (F2) capable of forming a vertically aligned liquid crystal aligning film. ) Was prepared.

<Synthesis Example 7>

BODA (2.439 g, 9.75 mmol), DAM-2 (1.295 g, 6.5 mmol), m-PDA (0.422 g, 3.9 mmol), and PCH (0.990 g, 2.6 mmol) are mixed in NMP (16.1 g), After reacting at 80°C for 5 hours, CBDA (0.535 g, 2.7 mmol) and NMP (8.05 g) were added and reacted at 40°C for 10 hours to obtain a polyamic acid solution. After NMP was added to this polyamic acid solution (36.0 g) and diluted to 6% by mass, acetic anhydride (6.31 g) and pyridine (1.95 g) were added as an imidation catalyst and reacted at 100°C for 3 hours. This reaction solution was poured into methanol (350 ml), and the obtained deposit was separated by filtration. Methanol wash|cleaned this deposit, it dried under reduced pressure at 100 degreeC, and obtained polyimide powder (G). The imidation ratio of this polyimide was 76 %, the number average molecular weight was 14000, and the weight average molecular weight was 46000.

NMP (14.6 g) was added to the obtained polyimide powder (G) (3.0 g), and it stirred and dissolved at 70 degreeC for 5 hours. A polyimide solution (G1) was obtained by adding and stirring NMP (17.4 g) and BC (15.0 g) to this solution.

Next, the polyamic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and this polyimide solution (G1) (8.0 g) were mixed at room temperature for 3 hours, and a liquid crystal aligning agent capable of forming a vertically aligned liquid crystal alignment film (G2) was prepared.

<Comparative Synthesis Example 1>

CBDA (2.447 g, 12.48 mmol) and DAM-5 (2.603 g, 13.0 mmol) were mixed in NMP (28.62 g) and reacted at room temperature for 20 hours to obtain a polyamic acid solution. To this polyamic acid solution, NMP (22.38 g) and BC (22.38 g) were added, diluted to 6% by mass, and stirred at room temperature for 5 hours to obtain a polyamic acid solution (H1). The number average molecular weight of the polyamic acid contained was 11000, and the weight average molecular weight was 29000.

Next, the polyamic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and the polyamic acid solution (H1) (8.0 g) were mixed at room temperature for 3 hours, and a liquid crystal aligning agent capable of forming a vertically aligned liquid crystal aligning film ( H2) was prepared.

<Comparative Synthesis Example 2>

CBDA (2.498 g, 12.74 mmol), and DAM-6 (1.978 g, 13.0 mmol) were mixed in NMP (25.37 g) and reacted at room temperature for 20 hours to obtain a polyamic acid solution. NMP (22.38 g) and BC (22.38 g) were added to this polyamic acid solution, diluted to 6% by mass, and stirred at room temperature for 5 hours to obtain a polyamic acid solution (I1). The number average molecular weight of the polyamic acid contained was 11000, and the weight average molecular weight was 28000.

Next, the polyamic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and this polyamic acid solution (I1) (8.0 g) were mixed at room temperature for 3 hours, and a liquid crystal aligning agent capable of forming a vertically aligned liquid crystal alignment film (I2) was prepared.

<Example 1>

Using the liquid crystal aligning agent (C2) obtained in Synthesis Example 3, the liquid crystal cell was produced in the procedure shown below.

[Production of liquid crystal cell]

The liquid crystal aligning agent (C2) obtained in Synthesis Example 3 was spin-coated on the transparent electrode formation surface of a glass substrate on which a transparent electrode made of an ITO film was formed, dried for 90 seconds on an 80°C hot plate, and then circulated with hot air at 200°C. It fired for 30 minutes in a type oven, and the liquid crystal aligning film of film thickness 50 nm was formed.

This substrate was irradiated with 20 mJ of linearly polarized UV (ultraviolet rays) at 313 nm with an irradiation intensity of 11.0 mW/cm. The direction of the incident light beam was inclined by 40° with respect to the substrate normal direction. Linearly polarized UV was adjusted by passing a 313 nm polarizing plate through the ultraviolet light of a high-pressure mercury lamp after passing a 313 nm band pass filter.

Two substrates by the above manufacturing method were prepared, and a 6 µm bead spacer was sprayed onto the liquid crystal alignment film of one substrate, and then a sealing agent was printed from thereon. Subsequently, the liquid crystal alignment surfaces of the two substrates are opposed to each other, press-bonding so that the projection direction of the optical axis of the linearly polarized UV light with respect to each substrate is antiparallel, and a sealing agent (manufactured by Kyoritsu Chemical Co., Ltd., XN -1500T) was thermally cured. A negative liquid crystal (MLC-6608 manufactured by Merck Co., Ltd.) having negative dielectric anisotropy (MLC-6608) having negative dielectric anisotropy was injected into the thus produced empty cell by a reduced pressure injection method to prepare a vertically aligned liquid crystal cell.

By the same production method, 5 kinds of vertically aligned liquid crystal cells of the same structure were prepared except that the film thickness of the liquid crystal alignment film was different from 70 nm, 100 nm, 120 nm, 150 nm, and 200 nm, respectively. , Used for the following evaluation.

[Evaluation of pretilt angle]

The pretilt angle of the liquid crystal was measured using each produced liquid crystal cell. The measurement of the pretilt angle was measured by the Muller matrix method using "Axo Scan" manufactured by Axo Metrix. The measurement results were put together in Table 1 and shown.

<Example 2>

Except having changed the liquid crystal aligning agent (C2) to the liquid crystal aligning agent (C3), according to the method similar to Example 1, 6 types of liquid crystal cells were produced, and the pretilt angle was measured about each.

<Example 3>

Except having changed the liquid crystal aligning agent (C2) to the liquid crystal aligning agent (D2), according to the method similar to Example 1, 6 types of liquid crystal cells were produced, and the pretilt angle was measured about each.

<Example 4>

Except having changed the liquid crystal aligning agent (C2) to the liquid crystal aligning agent (E2), according to the method similar to Example 1, 6 types of liquid crystal cells were produced, and the pretilt angle was measured about each.

<Example 5>

Except having changed the liquid crystal aligning agent (C2) to the liquid crystal aligning agent (F2), according to the method similar to Example 1, 6 types of liquid crystal cells were produced, and the pretilt angle was measured about each.

<Example 6>

Except having changed the liquid crystal aligning agent (C2) to the liquid crystal aligning agent (G2), according to the method similar to Example 1, 6 types of liquid crystal cells were produced, and the pretilt angle was measured about each.

<Comparative Example 1>

Six kinds of liquid crystals according to the same method as in Example 1, except that the polyamic acid solution (A1) was used as the liquid crystal aligning agent (A1), and the liquid crystal aligning agent (C2) was changed to the liquid crystal aligning agent (A1). A cell was produced, and the pretilt angle was measured for each.

<Comparative Example 2>

Six kinds of liquid crystal cells according to the same method as in Example 1 except that the polyimide solution (B1) was used as the liquid crystal aligning agent (B1) and the liquid crystal aligning agent (C2) was changed to the liquid crystal aligning agent (B1) Was produced, and the pretilt angle was measured for each.

<Comparative Example 3>

Except having changed the liquid crystal aligning agent (C2) to the liquid crystal aligning agent (H2), according to the method similar to Example 1, 6 types of liquid crystal cells were produced, and the pretilt angle was measured about each.

<Comparative Example 4>

Except having changed the liquid crystal aligning agent (C2) to the liquid crystal aligning agent (I2), according to the method similar to Example 1, 6 types of liquid crystal cells were produced, and the pretilt angle was measured about each.

The measurement result of the pretilt angle of each liquid crystal cell of Examples 1-6 was put together in Table 1, and was shown. Moreover, the measurement result of the pretilt angle of each liquid crystal cell of Comparative Examples 1-4 was put together in Table 2, and was shown.

In Tables 1 and 2, for each of Examples 1 to 6 and Comparative Examples 1 to 4, the amount of change (Δφ (degree)) in the pretilt angle depending on the film thickness of the liquid crystal aligning film was described.

Δφ is in each of Examples 1 to 6 and Comparative Examples 1 to 4, by comparing the pretilt angles of six types of liquid crystal cells having different film thicknesses of the liquid crystal aligning film to obtain the maximum pretilt angle and the minimum pretilt angle, and It is a value evaluated as a difference.

1 is a graph showing a relationship between a film thickness of an alignment film of a liquid crystal cell and a pretilt angle.

In FIG. 1, the phenomenon in which the pretilt angle of the liquid crystal fluctuates by changing the film thickness of the liquid crystal alignment film of the liquid crystal cell is shown by comparing the results of Example 6 and Comparative Example 4.

As shown in Table 2 and Comparative Example 4 in FIG. 1, the vertically aligned liquid crystal alignment film corresponding to the prior art, subjected to photo-alignment treatment, has a large change in the pretilt angle of the liquid crystal of the liquid crystal cell by changing the film thickness It can be seen that. This means that UV (ultraviolet rays) during the photoalignment treatment is reflected at the interface between the liquid crystal aligning film and the substrate, and interferes with the surface of the liquid crystal aligning film.

In addition, as shown in the graph of Example 6 in Table 1 and Fig. 1, by mixing (blending) a material having absorption in the ultraviolet region in the liquid crystal alignment film, the change in the pretilt angle due to the film thickness of the liquid crystal alignment film is suppressed. You can see what is going on. This is because the mixed materials absorb the reflected light, thereby suppressing light interference on the surface of the alignment film.

<Example 7>

Next, using a liquid crystal cell whose pretilt angle was measured in Examples 1 to 6 and Comparative Examples 1 to 4 and having a film thickness of 100 nm of the liquid crystal alignment film, the liquid crystal cell was placed on a backlight for a liquid crystal panel, Aging was performed for 300 hours while irradiating light from the backlight. Then, about each liquid crystal cell, the pretilt angle was measured similarly to the above, and the change (Δθ) of the pretilt angle before and after aging was evaluated. The evaluation results were put together in Table 3 and shown.

In addition, in Table 3, the pretilt angle of the liquid crystal cell before aging was shown as "pretilt angle 1", and the pretilt angle after aging was shown as "pretilt angle 2".

From the evaluation results in Table 3, in Comparative Examples 1 to 4, it was found that the pretilt angle changes significantly to a high value before and after aging due to the influence of backlight light. This is interpreted as because an unreacted photoreactive group that was not able to react in polarized UV at the time of alignment treatment gradually causes a photoreaction due to backlight light, and as a result, the anisotropy of the surface of the liquid crystal alignment film gradually decreases.

On the other hand, in a liquid crystal cell using a liquid crystal aligning agent in which a material having absorption in the ultraviolet region of Examples 1 to 6 was blended, it was confirmed that the change in the pretilt angle due to backlight light was suppressed. This is interpreted as showing the effect that the material having absorption in the ultraviolet region blended with the liquid crystal aligning agent absorbs ultraviolet rays generated from the backlight, and as a result, an unreacted photoreactive group involved in the orientation control ability becomes difficult to react.

Industrial availability

A liquid crystal display element formed using the liquid crystal aligning agent of the present invention and having a liquid crystal aligning film capable of photo-alignment treatment can be manufactured at high productivity and has excellent display characteristics. It can be suitably used as a display element for portable information terminals such as smartphones that display one image.

In addition, the specification of Japanese Patent Application No. 2012-182104 for which it applied on August 21, 2012, a claim, a drawing, and all the content of the abstract are referred here, and it takes in as an indication of the specification of this invention.

Claims (12)

A first polymer that reacts in light in a wavelength range of 250 to 380 nm,
A liquid crystal aligning agent comprising a second polymer having an absorption maximum in a wavelength range of 250 to 380 nm and having at least one specific structure among a phenone structure and a diphenylamine structure. The method of claim 1,
The liquid crystal aligning agent in which the content of the second polymer is 3 to 80% by mass of the total content combined with the first polymer. The method of claim 1,
The first polymer has a photoreactive group that reacts to the light, and the photoreactive group is at least one type of structure selected from the group consisting of a cinnamoyl structure, a coumarin structure, and a chalcone structure. The method of claim 3,
A liquid crystal aligning agent in which the photoreactive group contains any one of the following side chain structures.
[Formula 1]

(The broken line represents the binding group to the main chain of the polymer.
R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (however, any hydrogen atom may be substituted with a fluorine atom), or an alkoxyl group having 1 to 10 carbon atoms (however, the optional hydrogen atom is fluorine It may be substituted with an atom.) is shown.
A and B each independently represent a single bond or a ring structure represented by the following formula.
[Formula 2]

Each T independently represents a single bond, ether, ester, amide or ketone bond. S represents a single bond or an alkylene group having 1 to 10 carbon atoms.
However, when both S and A are single bonds, oxygen atoms are not adjacent.) The method of claim 1,
The liquid crystal aligning agent which is any structure whose said specific structure is represented by the following formula.
[Formula 3]

(R represents an alkyl group having 1 to 5 carbon atoms.) The method of claim 1,
The liquid crystal aligning agent wherein the first polymer is at least one polymer selected from the group consisting of polyamic acid and a polyimide obtained by imidizing the polyamic acid. The method of claim 1,
The liquid crystal aligning agent which contains the said 2nd polymer, and is at least 1 polymer selected from the group consisting of the polyimide obtained by imidizing the 2nd polymer by polyamic acid and the polyamic acid. A liquid crystal aligning film obtained from the liquid crystal aligning agent in any one of Claims 1-7. The method of claim 8,
A liquid crystal aligning film having a film thickness of 5 to 300 nm. A liquid crystal display device comprising the liquid crystal alignment film according to claim 8. delete delete

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