TWI726962B - Liquid crystal display element, liquid crystal optical element, and liquid crystal structure stabilized film composition - Google Patents

Abstract

Provides excellent display characteristics, electrical characteristics, etc., and is suitable for liquid crystal display elements such as large-screen and high-definition LCD TVs.

Contains a group of polyamides containing a side chain structure, polyamides containing a side chain structure, and polyimides formed from the aforementioned polyamides or polyamides At least one polymer selected from the group, an additive that can improve friction resistance, and a film for stabilizing a liquid crystal structure with an average surface roughness Ra of 1.0nm or less is arranged facing the liquid crystal structure attached. A liquid crystal display element containing a liquid crystal cell of a liquid crystal and a polarizing plate between the substrates of the body stabilizer film.

Description

Liquid crystal display element, liquid crystal optical element and liquid crystal structure stabilized film composition

The present invention relates to a liquid crystal display element in a liquid crystal alignment mode that has a very fast response speed and optically reacts to an applied voltage, and a liquid crystal cell, a substrate necessary for the production thereof, a film for stabilizing a liquid crystal structure, and a liquid crystal display element. In order to form such a film composition, etc.

In terms of liquid crystal display elements that are generally popular now, for example, TN (Twisted Nematic) mode, IPS (In Plane Switching) mode, VA (Vertical Alignment) mode, etc., but any driving method has liquid crystal On/Off cost. Time, that is, the subject of slow response speed, or the change of the viewing angle, that is, the subject of viewing angle dependence.

On the other hand, although it has not yet been put into practical use, Blue Phase or ULH (Uniform Lying Helix), which is a liquid crystal driving method with very fast response speed and no viewing angle dependence, has attracted attention as the next-generation liquid crystal driving method. Especially in ULH, because in addition to the very fast response speed, and the relatively low driving voltage, it also has an optical reflection that shows linearity in the applied voltage. In response to the unique characteristics, and look forward to the application in various display media.

ULH is one of the liquid crystal drive methods using cholesteric liquid crystal. The cholesteric liquid crystal is sandwiched by a substrate with transparent electrodes, and by applying physical shearing stress or electrical stimulation, it is possible to form a helix uniformly on the substrate plane. This alignment state is called ULH, but by applying an electric field to it, the optical axis of the spiral undergoes In Plane Switching, thereby obtaining a linear optical response.

On the other hand, it is very difficult for ULH alignment to obtain a uniform alignment state, and when placed under an electric field, there are technical issues such as irreversible changes in the alignment state of ULH. With regard to this problem, a liquid crystal with polymerizable liquid crystal added to a cholesteric liquid crystal is used. UV irradiation after ULH formation is used to form a polymer network structure to stabilize the ULH alignment (Patent Document 1). A method of forming ULH by applying a shear stress while injecting liquid crystals (Non-Patent Document 1) or a method of forming an alignment layer with a periodic structure by photolithography and aligning ULH (Non-Patent Document 2) And other means.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] US 7,038,743 B2

[Non-Patent Literature]

[Non-Patent Document 1] Liquid Crystals, 24: 3, 329-334, 1998

[Non-Patent Document 2] Mol. Cryst. Liq. Cryst. Vol.544: pp.37 /[1025]-49/[1037], 2011

Various methods are used in the alignment stabilization of ULH or the improvement of alignment uniformity. However, in the manufacturing steps of liquid crystal displays, it is extremely difficult to inject the liquid crystal while applying shear stress and perform alignment processing. The stabilization must also be implemented in a state where the uniform ULH alignment state is obtained, and the improvement of the uniformity of the ULH alignment is also a technically significant issue. Therefore, an object of the present invention is to provide a liquid crystal structure stabilizer film that can obtain uniform ULH alignment without applying physical stress, and a ULH display element provided with the liquid crystal structure stabilizer film.

In order to achieve the above-mentioned object, as a result of diligent research, it was found that in order to obtain uniform and good ULH alignment, it is necessary to contact with a helical structure composed of cholesteric liquid crystals and to make a film that can exist stably (hereinafter, also The present invention has been completed by several important elements that are called liquid crystal structure stabilizer film, which are small in unevenness and in order to reduce the unevenness of the structure stabilizer film.

That is, the present invention includes the following.

[1]

A composition used to form a film that stabilizes the liquid crystal structure (and The above-mentioned "liquid crystal structure stabilizer" is synonymous with polyamide acid having a side chain structure, polyamide acid having a side chain structure, and the aforementioned polyamide acid or polyamide acid ester A composition of at least one polymer selected from the group of imidized polyimides and additives that can improve friction resistance.

[2]

The aforementioned at least one polymer is a diamine component containing at least one diamine selected by the following formula, and a reaction product of a tetracarboxylic dianhydride component, polyamide acid, polyamide ester, or The composition described in [1] of soluble polyimide.

(A₁為碳數2~24的烷基或者含氟之烷基、或膽固醇基，A₂為-O-、-OCH₂-、-CH₂O-、-COOCH₂-、-NHCO-、-CONH-、或-CH₂OCO-，A₃為碳數1~22的烷基、烷氧基、含氟之烷基、或含氟之烷氧基。)

(A ₁ is an alkyl group with 2-24 carbons or a fluorine-containing alkyl group, or a cholesterol group, and A ₂ is -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -, -NHCO-, -CONH- or -CH ₂ OCO-, A ₃ is a C 1-22 alkyl group, alkoxy group, fluorine-containing alkyl group, or fluorine-containing alkoxy group.)

[3]

The aforementioned additives that can improve friction resistance are selected from phenolic resin additives, amino plastic additives, epoxy additives, and acrylic additives The composition described in [1] or [2] of the group consisting of an agent, a silane coupling agent, a blocked isocyanate-based additive, and an oxazoline-based compound.

[4]

The aforementioned at least one polymer contains the composition described in any one of [1] to [3] of a soluble polyimide having a imidization rate of 50% to 100%.

[5]

The composition described in any one of [1] to [4] of the composition used to form a film in which the cholesteric liquid crystal undergoes ULH alignment.

[6]

Contains a group of polyamides containing a side chain structure, polyamides containing a side chain structure, and polyimides formed from the aforementioned polyamides or polyamides A film for stabilizing liquid crystal structures with at least one polymer selected from the group, and additives that can improve friction resistance, and having an average surface roughness Ra of 1.0nm or less (hereinafter referred to as "liquid crystal structure stability" "Chemical film").

[7]

The film described in [6] whose pretilt angle measured using nematic liquid crystal is 3°-20°.

[8]

The film described in [6] or [7] in which the average surface roughness Ra after the alignment treatment is 1.0 nm or less.

[9]

The aforementioned alignment treatment is the film described in [8] that is rubbed using rayon or cotton that has been treated to reduce the abrasion of the cloth to impart uniaxial alignment of the liquid crystal.

[10]

The film described in any one of [6] to [9] of the film in which the cholesteric liquid crystal is subjected to ULH alignment.

[11]

A substrate with a liquid crystal structure stabilizing film having the film described in any one of [6] to [10].

[12]

The liquid crystal structure stabilizer films are arranged to face each other, and the liquid crystal cell of the liquid crystal is contained between the substrates with the liquid crystal structure stabilizer film described in [11].

[13]

The aforementioned liquid crystal is the liquid crystal cell described in [12] of cholesteric liquid crystal.

[14]

The above-mentioned cholesteric liquid crystal is a liquid crystal cell described in [13] of a cholesteric liquid crystal containing a liquid crystal compound represented by the following general formula.

X ₁ and X ₂ are independent of each other and are a bonding group selected from a single bond, an ester bond, and an ether bond, L is an integer represented by 6-20, and R ₈ is an alkyl group with 4-10 carbons.

[15]

A liquid crystal display element provided with a polarizing plate and the liquid crystal cell described in any one of [12] to [14].

According to the present invention, good ULH alignment can be obtained without applying external stress or the like.

[Fig. 1] A schematic diagram of a unit cell for evaluating the ULH alignment of cholesteric liquid crystals caused by a film formed on a substrate.

[Figure 2] The evaluation result of the initial alignment and the graph of a case where the ULH alignment is good.

[Figure 3] The evaluation result of the initial alignment and the graph when the ULH alignment is poor.

[Best form to implement the invention]

Hereinafter, each constituent element of the present invention will be described in detail.

1. Liquid crystal structure stabilizing film

The stabilizing film of the liquid crystal structure used in the present invention, after alignment treatment The average surface roughness (hereinafter, also referred to as surface roughness) Ra needs to be 1.0 nm or less. If the surface roughness is higher than that, there are cases where the uniform ULH alignment cannot be obtained.

The aforesaid alignment treatment generally uses rubbing treatment, but in this method, it is easy to produce film cutting or adhesion of dust from the cloth during the alignment treatment, and the extension of the film is easy to change due to the influence of the vibration of the drum or the hairiness, etc. It's uneven. The ULH alignment is a very fine alignment state, so due to the above-mentioned reasons, there are irregularities in the stabilizing film of the liquid crystal structure, and it becomes impossible to obtain a good alignment. Therefore, the liquid crystal structure stabilizing film used in the liquid crystal display element of the present invention is preferably a material that is less prone to unevenness during film formation on the substrate, and has little chipping or adhesion of dust during rubbing treatment. It is recommended to use rayon or cotton that has been treated to reduce the wear of the cloth for rubbing.

Although there are many methods for measuring surface roughness, by using scanning probe microscope (SPM), especially atomic force microscope (Atomic Force Microscope; AFM) for measurement, the roughness in a certain area can be easily visualized and digitized. The average value Zc of the height of the measured sample unevenness is calculated, and the average surface roughness (Ra) can be obtained by obtaining the average value of each height data Z(i) minus Zc.

When there are irregularities on the substrate etc., it is necessary to obtain Ra by measuring as much as possible at the place where there is no step. In the liquid crystal alignment film for ULH, the surface roughness before and after the rubbing treatment (Ra below) is as close to 0 as possible, and it is about 0nm~1nm. Within the range, ULH alignment can be obtained. A particularly preferred range is 0nm~0.5nm.

The cutting condition or the adhesion condition of dust also changes due to the friction conditions, but within the aforementioned surface roughness range, the friction conditions are not particularly limited, and a good ULH alignment can be obtained by finding the most suitable friction conditions.

Regarding the alignment of ULH, it is known that liquid crystals form a cholesteric phase, and the spirals are aligned in a flat surface. The alignment shape of nematic liquid crystals such as IN, VA, and IPS is greatly different, and the portion aligned horizontally in a certain period, the portion aligned with the pretilt angle, and the portion aligned vertically are continuously present. It is believed that if a liquid crystal structure stabilizer film that can cause alignment in accordance with this period can be produced, better alignment can be obtained.

On the other hand, ULH liquid crystals are mixed with chiral liquid crystals with strong helical twisting power, and the liquid crystal itself is induced to self-organize into a spiral state. Therefore, it is thought that a liquid crystal alignment film that aligns liquid crystals in a specific direction may hinder spiral formation. On the other hand, when the spiral arrangement is in a uniaxial direction, it is considered that it needs to use some driving force to arrange it because it cannot be arranged directly. Therefore, the use of a liquid crystal alignment film to form ULH requires a very delicate design.

The liquid crystal structure stabilizing film used in the present invention must stabilize the alignment of the spiral structure liquid crystal formed by gathering cholesteric liquid crystals. Therefore, if the interaction between the individual cholesteric liquid crystals constituting the liquid crystal of the structure and the stabilizing film of the liquid crystal structure is too strong, the spiral structure collapses and is not suitable. In order to prevent this, the polymer constituting the stabilization film of the liquid crystal structure preferably has a side chain structure.

Although the structure or introduction amount of the side chain is not particularly limited, it is preferable to use nematic liquid crystals for horizontal alignment. The pretilt angle is about 2.5 to 30°. Especially preferably, it is between 3 and 15°.

The liquid crystal structure stabilizer film used in the present invention is a material having the aforementioned characteristics. The type of polymer is not particularly limited, but from the viewpoint of heat resistance, etc. Polyimine precursors and polyimine are preferred.

2. Liquid crystal structure stabilizer

The liquid crystal structure stabilizing film used in the liquid crystal display element of the present invention is composed of a polyimide precursor containing a side chain structure and a polyimide formed by imidizing it. At least one selected polymer and a liquid crystal structure stabilizer with a crosslinking additive are preferable.

The liquid crystal structure stabilizer used in the present invention is a solution in which the polymer forming the liquid crystal structure stabilizer film and crosslinkable additives contained as necessary are dissolved in an organic solvent.

In the liquid crystal structure stabilizer, different polymers can be used if necessary. However, if polymers with a large difference in surface energy are mixed, separation occurs during film formation, which may cause unevenness of the resulting film, so it is preferable It is better to use a single polymer or a mixture of polymers with similar surface energy.

2.1. Polyimide precursors and polyimine

Polyimide precursors are polyamide acid and polyamide acid ester. Polyamide acid is obtained by reacting diamine component with tetracarboxylic acid component, polyamide acid ester It can be obtained by condensation polymerization of a diester of tetracarboxylic acid and diamine. Polyimine can be obtained by heating and dehydrating these polyimine precursors, and dehydrating condensation using a catalyst such as acid or alkali.

The polyimide precursor has a structure represented by the following formula [A].

(式中，R¹為4價有機基。R²為2價有機基。A¹及A²各自獨立，為氫原子或碳數1~4的烷基。A³及A⁴各自獨立，為氫原子、碳數1~5的烷基或乙醯基。n為正整數。)

(In the formula, R ¹ is a tetravalent organic group. R ² is a divalent organic group. A ¹ and A ² are each independently a hydrogen atom or an alkyl group having 1 to 4 carbons. A ³ and A ⁴ are each independent and are Hydrogen atom, C1-C5 alkyl group or acetyl group. n is a positive integer.)

Polyamide acid or polyamide acid ester initiates a condensation reaction during firing to be converted into polyimide, but the volume changes at this time, and there is a possibility of forming unevenness of the film. In addition, there is a possibility that the rate of partial imidization may be different due to the way of heat application, and therefore there is a risk that the ability to attract liquid crystal molecules, that is, the unevenness of the liquid crystal alignment control force, and the unevenness of the film may occur. Furthermore, because polyamide acid contains a large amount of carboxylic acid, it is easy to entrain solvent, and has adhesiveness to the film, so it is easy to adhere to dust from the friction cloth, and the roughness of the film surface is likely to increase. On the other hand, it is believed that because the volume change of the soluble polyimide during firing is small, there is almost no unevenness during film formation. In particular, because the soluble polyimide is low in polarity, it is not easy to entrain solvents and the adhesiveness is also low, so when rubbing Slag from the cloth is not easy to adhere. Therefore, from the viewpoint of making the roughness smaller, it is better to use soluble polyimide. Specifically, with 50%~100% Soluble polyimide with amination rate is better, more preferably 70%-100%.

Regarding the polyimide-based polymer, by using the tetracarboxylic dianhydride represented by the following formula [B] and the diamine represented by the following formula [C] as raw materials, it can be obtained relatively simply because The polyimide formed by the structural formula of the repeating unit represented by the following formula [D] or the polyimide obtained by the imidization of the polyimide is preferable.

(式中，R¹及R²與式[A]定義者同義。)

(In the formula, R ¹ and R ² have the same meaning as those defined by formula [A].)

(式中，R¹及R²與式[A]定義者同義。)

(In the formula, R ¹ and R ² have the same meaning as those defined by formula [A].)

2.1.1. Diamine compounds

The diamine component is a diamine having two primary or secondary amine groups in the molecule. In terms of the tetracarboxylic acid component, for example, tetracarboxylic acid, tetracarboxylic dianhydride, tetracarboxylic dihalide, etc., tetracarboxylic acid The diester body includes, for example, a dialkyl tetracarboxylic acid or a dialkyl tetracarboxylic acid dihalide.

For the above reasons, the liquid crystal structure stabilizing film of the present invention preferably has a side chain structure. To introduce a side chain into the polyimide-based polymer, it is preferable to use a diamine compound having a side chain structure. Diamine compound with side chain structure Although the structure of is not particularly limited, the structure shown in the following general formulas Y-112~118 is particularly preferred.

A ₁ is an alkyl group with 2-24 carbons or a fluorine-containing alkyl group, or an organic group selected by cholesterol, and A ₂ is -O-, -COO-, -OCO-, -OCH ₂ -, -CH ₂ O -, -COOCH ₂ -, -NHCO-, -CONH- or -CH ₂ OCO-, A ₃ is a C 1-22 alkyl group, alkoxy group, fluorine-containing alkyl group or fluorine-containing alkoxy group.

The diamine used in the polyimide-based polymer contained in the liquid crystal structure stabilizer of the present invention, in addition to the above-mentioned diamine containing a side chain structure, is within the range of not impairing the characteristics of the obtained ULH liquid crystal display element Also, R ² is a diamine having the following structure. In addition, the point in the formula is the part directly bonded to the amino group.

In the present invention, these diamine structures play a very important role in the improvement of friction resistance, so it is better to actively introduce them, especially Y-82 or Y-94~Y-108.

2.1.2. Tetracarboxylic dianhydride

Tetracarboxylic dianhydride can be represented by the following general formula (TC).

X is a tetravalent organic group, and its structure is not particularly limited.

The type of tetracarboxylic dianhydride used in the present invention is not particularly limited, and one type or two or more types can be used in combination in accordance with the characteristics of voltage retention and accumulated charge when forming the liquid crystal alignment film.

Specific examples of X are shown below, but are not limited to these structures.

When preparing soluble polyimides, solubility in solvents is an important physical property. Therefore, from the viewpoint of solubility, alicyclic tetracarboxylic dianhydrides such as X-1 to 26 are preferred, and X- 2. X-3, X-4, X-6, X-9, X-10, X-11, X-12, X-13, X-14, X-15, X-16, X-17, X-18, X-19, X-20, X-21, X-22, X-23, X-24, X-25, X-26 are preferred. On the other hand, in terms of alignment, aromatic tetracarboxylic dianhydrides like X27~46 are preferred, especially X-27, X-28, X-33, X-34, X-35, X-40 , X-41, X-42, X-43, X-44, X-45, X-46 are preferred.

Particularly preferred are X-1, X-2, X-18~22, X-25, X-26 with appropriate alignment and solubility.

2.2. Additives 2.2.1. Cross-linking additives that can improve friction resistance

The liquid crystal structure stabilizer used in the liquid crystal display element of the present invention preferably contains a cross-linking additive that can improve rubbing resistance.

Examples of crosslinkable additives include phenolic resin additives Additives, amino plastic additives, epoxy additives, acrylic additives, silane coupling agents, blocked isocyanate additives, oxazoline compounds, β-hydroxyalkyl amide (Primid) crosslinking agents, etc., but Not limited to this.

Specific examples of phenol resin additives are shown below, but are not limited to these.

Amino plastic additives

The crosslinkable compound having at least one substituent selected from the group consisting of a hydroxyl group or an alkoxy group includes, for example, an amino resin having a hydroxyl group or an alkoxy group, such as melamine resin, urea resin, and guanamine resin , Glycoluril-formaldehyde resin, succinylamide-formaldehyde resin, ethylene urea-formaldehyde resin, etc.

As the crosslinkable compound, for example, a melamine derivative, a benzoguanamine derivative, or a glycoluril in which the hydrogen atom of the amino group is substituted with a methylol group or an alkoxymethyl group or both of them can be used. The melamine derivatives and benzoguanamine derivatives may also exist as dimers or trimers. These are preferably those having an average of 3 or more and 6 or less hydroxymethyl or alkoxymethyl groups per triazine ring.

Examples of such melamine derivatives or benzoguanamine derivatives include, for example, MX-750, which has an average of 3.7 substitutions of methoxymethyl groups per triazine ring of commercially available products, and per triazine ring MW-30 (above, manufactured by SANWA CHEMICAL CO., LTD.) or Cymel 300, 301, 303, 350, 370, 771, 325, MW-30 (above, manufactured by SANWA CHEMICAL CO., LTD.) with an average of 5.8 substitutions of methoxymethyl Methoxy methylated melamine of 327, 703, 712, etc., methoxy methylated butoxy methylated melamine of Cymel 235, 236, 238, 212, 253, 254, etc., butoxy of Cymel506, 508, etc. Methylated melamine, Cymel1141, methoxymethylated isobutoxymethylated melamine containing carboxyl group, Cymel1123, methoxymethylated ethoxymethylated benzoguanamine, Cymel1123-10, methoxymethylated Butoxymethylated benzoguanamine, Cymel1128, butoxymethylated benzoguanamine, Cymel1125-80, methoxymethylated ethoxymethylated benzoguanamine with carboxyl group Amine (above, manufactured by Mitsui-Cyanamid). In addition, as examples of glycolurils, butoxymethylated glycolurils like Cymel 1170, methylolated glycolurils like Cymel 1172, etc., and methoxymethylated glycolurils like POWDER LINK 1174 can be mentioned.

Epoxy additives

Crosslinkable compounds with epoxy groups or isocyanate groups, such as bisphenol acetone glycidyl ether, phenol novolac epoxy resin, cresol novolac epoxy resin, triglycidyl isocyanurate, four Glycidylamino diphenylene, tetraglycidyl-m-xylene diamine, tetraglycidyl-1,3-bis(aminoethyl)cyclohexane, tetraphenylglycidyl ether ethane , Triphenyl glycidyl ether ethane, bisphenol hexafluoroacetone diglycidyl ether, 1,3-bis(1-(2,3-epoxypropoxy)-1-trifluoromethyl- 2,2,2-Trifluoromethyl)benzene, 4,4-bis(2,3-epoxypropoxy)octafluorobiphenyl, triglycidyl-p-aminophenol, tetraglycidyl M-xylene diamine, 2-(4-(2,3-epoxypropoxy)phenyl)-2-(4-(1,1-bis (4-(2,3-epoxypropoxy)phenyl)ethyl)phenyl)propane, 1,3-bis(4-(1-(4-(2,3-epoxypropoxy) Yl)phenyl)-1-(4-(1-(1-(4-(2,3-epoxypropoxyphenyl)-1-methylethyl)phenyl)ethyl)phenoxy)- 2-Propanol, etc. Compounds containing two or more epoxy groups, specifically, for example, the following compounds.

Oxetane

The crosslinkable compound having an oxetanyl group is a crosslinkable compound having at least two oxetanyl groups represented by the following formula [4].

Specifically, for example, a crosslinkable compound represented by the following formula [4a] to formula [4k] can be mentioned.

Blocked isocyanate additives

The compound containing two or more blocked isocyanate groups includes, for example, a compound having a blocked isocyanate group represented by the following formula (5).

Z is each independently and is an alkyl group having 1 to 3 carbons, a hydroxyl group, or an organic group represented by the following formula (6), and at least one of Z is an organic group represented by the following formula (6).

Specifically, the compounds are as follows.

The compound containing two or more blocked isocyanate groups other than the above formula (7) is, for example, the following compound.

Oxazoline compounds

As for the oxazoline compound, for example, 2,2'-bis(2-oxazoline), 1,2,4-gin-(2-oxazoline-2)-benzene, 4-furan-2- Methylene-2-phenyl-4H-oxazol-5-one, 1,4-bis(4,5-dihydro-2-oxazolyl)benzene, 1,3-bis(4,5-di Hydrogen-2-oxazolyl)benzene, 2,3-bis(4-isopropenyl-2-oxazolin-2-yl)butane, 2,2'-bis-4-benzyl-2-oxa Oxazoline, 2,6-bis(isopropyl-2-oxazoline-2-yl)pyridine, 2,2'-isopropylidene bis(4-tert-butyl-2-oxazoline), 2,2'-isopropylidene bis(4-phenyl-2-oxazoline), 2,2'-methylidene bis(4-tert-butyl-2-oxazoline), and 2, 2'-Methylenebis(4-phenyl-2-oxazoline). In addition to these, for example, a polymer or oligomer having an oxazole group such as Epocros (trade name, manufactured by Nippon Shokubai Co., Ltd.) can also be used.

Primid series crosslinking agent

The Primid-based crosslinking agent is a compound having a hydroxyalkylamido group. (B) If the component has a hydroxyalkylamido group, other structures are not particularly limited, but from the viewpoint of availability and the like, preferred examples include, for example, the compound represented by the following formula (2).

X ₂ is an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an n-valent organic group containing an aromatic hydrocarbon group. n is an integer from 2 to 6.

R ₂ and R ₃ are independent of each other and are a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, an optionally substituted carbon number 2 to 4 alkenyl group, or an optionally substituted carbon number 2 to 4's alkynyl. In addition, _{at least one of R 2} and R ₃ is a hydrocarbon group substituted with a hydroxyl group.

_{Among them, the atom directly bonded to the carbonyl group in X 2} of the formula (2) is a carbon atom that does not form an aromatic ring, and it is preferable from the viewpoint of liquid crystal alignment. _{In addition, X 2 of the} formula (2) is preferably an aliphatic hydrocarbon group, and more preferably has a carbon number of 1 to 10, from the viewpoint of liquid crystal alignment and solubility.

In formula (2), n is preferably 2 to 4 from the viewpoint of solubility.

In the formula (2), _{at least one of R 2} and R ₃ has a structure represented by the following formula (3), which is preferable from the viewpoint of reactivity, and the structure represented by the following formula (4) is even more preferable .

In formula (3), R ₄ to R ₇ are independent of each other and are a hydrogen atom, a hydrocarbon group, or a hydrocarbon group substituted with a hydroxyl group.

(B) Preferable specific examples of the component include the following compounds.

One type of these crosslinkable additives can be added, but multiple types can be added to the extent that the characteristics of the present invention are not impaired.

The preferred addition amount is 0.1% by weight to 30% by weight, more preferably 0.5% by weight to 10% by weight.

Crosslinkable compound with polymerizable unsaturated bond

As for the crosslinkable compound having a polymerizable unsaturated bond, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, tri(meth)acrylate Meth) acryloxy ethoxy trimethylolpropane, glycerol polyglycidyl ether poly(meth)acrylate, etc., crosslinkable compounds having 3 polymerizable unsaturated groups in the molecule, and further ethyl acetate Glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate Base) acrylate, polypropylene glycol di(meth)acrylate, butene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide bisphenol A type two( Meth) acrylate, propylene oxide bisphenol type di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, glycerol di(meth)acrylate, pentaerythritol bis(meth)acrylate )Acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, phthalic acid diglycidyl ether di(meth) Acrylate, hydroxypivalate neopentyl glycol di(meth)acrylate, etc., crosslinkable compounds having two polymerizable unsaturated groups in the molecule, and 2-hydroxyethyl (meth)acrylate , 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-phenoxy-2-hydroxypropyl (meth)acrylate, 2-(meth)propylene Acetyloxy-2-hydroxypropyl phthalate, 3-chloro-2-hydroxypropyl (meth)acrylate, glycerol mono(meth)acrylate, 2-(meth)acrylic acid ester Crosslinkable compounds having one polymerizable unsaturated group in the molecule, such as oxyethyl phosphate and N-methylol (meth)acrylamide.

In addition, the compound represented by the following formula [5] can also be used.

(式[5]中，A₁為環己基環、雙環己基環、苯環、聯苯基環、聯三苯環、萘環、茀環、蒽環、或菲環所選出的基，A₂為下述之式[5a]、或式[5b]所選出的基，n為1~4的整數)。

(In formula [5], A ₁ is a group selected from a cyclohexyl ring, a bicyclohexyl ring, a benzene ring, a biphenyl ring, a terphenyl ring, a naphthalene ring, a sulphur ring, an anthracene ring, or a phenanthrene ring, and A ₂ It is the group selected by the following formula [5a] or formula [5b], n is an integer of 1 to 4).

The above-mentioned compound is an example of a crosslinkable compound, but it is not limited to these. In addition, the crosslinking compound contained in the liquid crystal alignment treatment agent of the present invention may be one type or a combination of two or more types.

Thiolane compounds

As for the thiopropylene compound, for example, phenyl glycidyl ether, butyl glycidyl ether, 3,3,3-trifluoromethyl propylene oxide, styrene oxide, hexafluoropropylene oxide, Cyclohexene oxide, N-glycidyl phthalimide, (nonafluoro-N-butyl) epoxide, perfluoroethyl glycidyl ether, epichlorohydrin, epibromohydrin, N , N-diglycidyl aniline, and 3-[2-(perfluorohexyl)ethoxy]-1,2-epoxypropane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl Base ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether Glycidyl ether, glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, and 3-(N,N-diglycidyl)aminopropyltrimethoxysilane , 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis( N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N',-tetraglycidyl-4,4'-diaminodiphenylmethane, and 3-( The glycidyl oxygen in N-allyl-N-glycidyl)aminopropyltrimethoxysilane is substituted with sulfur according to the method described in, for example, J. Org. Chem., 28, 229 (1963), so that The aforementioned glycidyl group is converted to an episulfide group.

Aziridine compounds

As for the aziridine compound, for example, 2,4,6-ginseng(1'-aziridinyl)-1,3,5-triazine, ω-aziridinylpropionic acid-2,2-dihydroxy Methyl-butanol triester, 2,4,6-ginseng (2-methyl-1-aziridinyl)-1,3,5-triazine, 2,4,6-ginseng (2-ethyl -1-aziridinyl)-1,3,5-triazine, 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane, bis(2-ethyl-1-nitrogen) Propidinyl)benzene-1,3-dicarboxylic acid amide, ginseng(2-ethyl-1-aziridinyl)benzene-1,3,5-tricarboxylic acid amide, bis(2-ethyl -1-aziridinyl) sebacic acid amide, 1,6-bis(ethyleneiminocarbonylamino)hexane, 2,4-diethyleneureidotoluene, 1,1'- Carbonyl-bis-ethyleneimine, polymethylethylene-bis-ethyleneurea (C2~C4), and N,N'-bis(4,6-diethyleneimino-1,3 ,5-Triazin-2-yl)-hexamethylene diamine. In addition to these, for example, an oligomer or polymer having an aziridinyl group may also be mentioned.

Cyclic carbonate

2.2.2. Arbitrary ingredients

The liquid crystal structure stabilizer used in the present invention may contain components other than the above-mentioned polymer components and crosslinkable additives. As an example, it is a solvent that improves the uniformity of the film thickness or the surface smoothness when the liquid crystal structure stabilizer is applied. Agents or compounds, compounds that improve the adhesion between the stabilizing film of the liquid crystal structure and the substrate, etc.

Specific examples of the solvent (lean solvent) that improves the uniformity of the film thickness or the surface smoothness are as follows.

Such as 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 monobutyl ether, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene two Alcohol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, two Propylene 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 butyl, butyl ether, diisobutyl ketone, methyl cyclohexene, 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 acetate Monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate Ester, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl ester, 3-methoxypropionic acid butyl ester, 1-methoxy-2-propanol , 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol Alcohol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-( 2-ethoxypropoxy) propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate and other solvents with low surface tension, etc. .

These poor solvents can be of one type or a mixture of multiple types. When the above-mentioned solvents are used, 5 to 80% by mass of the total solvent contained in the liquid crystal structure stabilizer is preferably 5 to 80% by mass, and more preferably 20 to 60% by mass.

As for the compound that improves the uniformity of the film thickness or the surface smoothness, for example, a fluorine-based surfactant, a silicone-based surfactant, a nonionic surfactant, and the like can be mentioned.

More specifically, for example, EFTOP EF301, EF303, EF352 (manufactured by Thochem Products.), MEGAFAC F171, F173, R-30 (manufactured by Dainippon Ink Corporation), Fluorad FC430, FC431 (manufactured by Sumitomo 3M), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Company), etc. The use ratio of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal structure stabilizer.

Specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include the following functional silane-containing compound or epoxy group-containing compound.

For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane Alkyl, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3 -Ureaylpropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-amine Propyl triethoxysilane, N-triethoxysilylpropyl tridiethylenetriamine, N-trimethoxysilylpropyltridiethylenetriamine, 10-trimethoxysilyl-1, 4,7-Triazadecane, 10-Triethoxysilyl-1,4,7-Triazadecane, 9-Trimethoxysilyl-3,6-diazanonylacetic acid Esters, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyl Triethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(ethylene oxide)-3- Aminopropyltrimethoxysilane, N-bis(ethylene oxide)-3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol two Glycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether Ether, 2,2-Dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N'- Tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl- 4. 4'-Diaminodiphenylmethane, etc.

When using a compound that improves the adhesion to the substrate, the amount used is preferably 0.1-30 parts by mass, more preferably 1-20 parts by mass relative to 100 parts by mass of the polymer component contained in the stabilizer of the liquid crystal structure Mass parts. use If the amount is less than 0.1 parts by mass, the adhesion improvement effect cannot be expected, and if the amount is more than 30 parts by mass, the liquid crystal alignment may deteriorate.

In the liquid crystal structure stabilizer of the present invention, in addition to the above, without impairing the scope of the present invention, for the purpose of changing the dielectric constant or conductivity of the liquid crystal alignment film, a dielectric or The conductive material may be further added with a cross-linking compound for the purpose of increasing the hardness or density of the film when the liquid crystal alignment film is formed.

2.3. Preparation of organic solvent and liquid crystal structure stabilizer

The liquid crystal structure stabilizer used in the present invention is contained in a form in which the above-mentioned polymer and additives are dissolved in an organic solvent. In the liquid crystal structure stabilizer, the polymer preferably contains 1 to 15% by mass, more preferably 2 to 10% by mass, and still more preferably 2 to 8% by mass. In addition, the liquid crystal structure stabilizer of the present invention may contain polyamide acids and polyamide esters other than the above-mentioned polymers without impairing the effects of the present invention. Polyimide and other polymers (above, these are also referred to as "other polymers").

When the liquid crystal structure stabilizer of the present invention contains other polymers, it is preferably 10 to 1000 parts by mass, and more preferably 10 to 800 parts by mass relative to 100 parts by mass of the above-mentioned polymer.

The organic solvent contained in the liquid crystal structure stabilizer is preferably 90 to 97% by mass, more preferably 93 to 96% by mass.

In the liquid crystal structure stabilizer used in the present invention, the organic solvent used to dissolve each polymer is the organic solvent used to dissolve the polymer component It is not particularly limited. The specific example is as follows.

For example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactone, 2-pyrrolidone , N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl sulfide, tetramethylurea, pyridine, dimethyl sulfide, γ-butyrolactone, 3-methoxy-N,N -Dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, 1,3-dimethyl- Imidazolinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, vinyl carbonate, propylene carbonate, diethylene glycol Alcohol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, etc. These can be used alone or in combination.

3. Manufacturing method of liquid crystal display element

The liquid crystal display element formed using the liquid crystal structure stabilization film of this invention can be manufactured as follows, for example.

3.1. Liquid crystal cell

First, as described above, a pair of substrates on which a liquid crystal structure stabilizing film is formed is prepared, and a liquid crystal cell having a structure that holds liquid crystal between the pair of substrates is manufactured. For manufacturing the liquid crystal cell, the following two methods can be mentioned, for example.

The first method is a method known in the past. First, a gap (cell gap) is interposed so that the stabilizing films of each liquid crystal structure face each other. The two substrates are arranged facing each other, and the peripheral parts of the two substrates are bonded together using a sealant. After injecting and filling the liquid crystal into the cell gap of the sealant partition, the liquid crystal cell can be manufactured by sealing the injection hole.

The method of obtaining the cell gap is not particularly limited. For example, a method of uniformly spreading spacer beads (alumina balls) on a substrate provided with a stabilizing film of a liquid crystal structure and then bonding, or a method of bonding on a sealant without spreading After the spacer beads are dispersed in the middle, the method of setting the cell gap by coating and bonding, using a substrate provided with a structure that uses a photoresist in advance to become a specific cell gap, etc.

Because the alignment of ULH is strongly affected by foreign matter, etc., it is better to have no spacer beads in the pixel. Therefore, it is preferable to disperse spacer beads in the sealant to ensure a cell gap, or to use a substrate provided with a structure that uses a photoresist in advance to form a specific cell gap.

The second method is called ODF (One Drop Fill) method. Apply an ultraviolet curable sealant to a designated place on one of the two substrates forming the stabilizing film of the liquid crystal structure, and then drop liquid crystal on the liquid crystal alignment film surface to stabilize the liquid crystal structure. The chemical film is bonded to another substrate in an opposing manner, and then the sealant is cured after the substrate is irradiated with ultraviolet light to produce a liquid crystal cell.

As for the aforementioned sealant, for example, an epoxy resin containing a hardening agent or the like can be used.

In the case of either method, it is better to then heat the liquid crystal cell to the temperature at which the used liquid crystal becomes the isotropic phase and then cool it to room temperature to remove the flow alignment during liquid crystal filling.

3.2. Cholesterol-like liquid crystal

The liquid crystal used in the ULH alignment mode is a cholesteric liquid crystal, but for To obtain a more stable ULH alignment, it is necessary to use a liquid crystal that can obtain a strong flexural effect. As the liquid crystal that can obtain the flexural electric effect, for example, the following two mesogen type liquid crystals can be exemplified. By using a cholesteric liquid crystal having such a structure, ULH alignment can be obtained, but it is not limited to this.

(式中，X₁、X₂各自獨立，為單鍵、酯鍵、醚鍵所選出的鍵結基，L為6~20所表示之整數。)

(In the formula, X ₁ and X ₂ are independent of each other and are the bonding group selected from single bond, ester bond, and ether bond, and L is an integer represented by 6-20.)

In addition, in order to obtain cholesteric liquid crystal properties with a short twist period by using liquid crystals with such a structure, it is preferable to use a chiral reagent added with a strong helical twisting power of 1 to 5 wt%. If cholesteric liquid crystal properties can be obtained The structure is not particularly limited, and particularly preferred chiral reagents include the following compounds.

(式中，X₁、X₂各自獨立，為單鍵、酯鍵、醚鍵所選出的鍵結基，R₈為3~10的烷基。)

(In the formula, X ₁ and X ₂ are independent of each other, and are a bonding group selected from a single bond, an ester bond, and an ether bond, and R ₈ is an alkyl group of 3-10.)

3.3. Orientation processing

By injecting the above-mentioned cholesteric liquid crystal into the liquid crystal cell provided with the above-mentioned alignment film, heating treatment and applying an electric field at the same time, it can be transformed into ULH Alignment. For example, when the temperature is raised to the temperature at which the used liquid crystal becomes the isotropic phase, it is confirmed that the liquid crystal is completely transformed into the isotropic phase, and the liquid crystal cell is slowly returned to room temperature while applying a voltage, and the ULH alignment can be induced.

The conditions vary depending on the cell gap or the type of liquid crystal used, so the preferred temperature drop rate or the type or intensity of the applied voltage cannot be limited, but the temperature drop rate from the temperature at which the isotropic phase becomes the isotropic phase is preferably per minute 1~30℃, more preferably 1~10℃, applied voltage of 1~10V/μm, preferably 2~8/μm, rectangular wave AC with electric field strength is better, and the frequency is 1~1KHz, more preferably It is 10~300Hz.

3.4. Polarizing plate

By attaching a polarizing plate to the outer surface of the liquid crystal cell, a desired liquid crystal display element can be obtained. Here, the desired liquid crystal display element can be obtained by appropriately adjusting the angle of the polarization direction of the linearly polarized radiation irradiated on the two substrates on which the stabilizing film of the liquid crystal structure is formed and the angle between each substrate and the polarizing plate. .

As for the polarizing plate used on the outside of the liquid crystal cell, for example, a polarizing plate formed by sandwiching a polarizing film called "H film" with a cellulose acetate protective film, or a polarizing plate composed of the H film itself, etc. , And the above-mentioned "H film" is a polarizing film formed by absorbing iodine while stretching or oriented polyvinyl alcohol.

[Example]

Hereinafter, the present invention will be explained with examples, but the present invention is of course not limited to these.

4. Preparation and evaluation of stabilizer for liquid crystal structure 4.1. Abbreviations

The abbreviations of the compounds used in Examples and Comparative Examples are as follows. MW is the molecular weight.

<Tetracarboxylic dianhydride>

TC-1: 1,2,3,4-cyclobutane tetracarboxylic dianhydride (MW196)

TC-2: 3,4-Dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride

TC-3: pyromellitic dianhydride

<Diamine>

DA-1: 1,4-phenylenediamine

DA-2: B-3: 4,4-Diaminodiphenylmethane

DA-3: 4-aminobenzylamine

DA-4: 3-aminobenzylamine

DA-5: N,N-diallylamino-2,4-diaminobenzene

DA-6: 2-Dodecyloxy-2,4-diaminobenzene

DA-7: 4-(trans-4-pentylcyclohexyl)benzamide-2’,4’-phenylenediamine

DA-8: 2-octadecyloxy-2,4-diaminobenzene

DA-9: 1,5-bis(4-aminophenoxy)heptane

<Crosslinking additives>

Ad-1: Bis-(3,5-bis-hydroxymethyl-4-hydroxyphenyl)dimethylmethane

<Organic solvent>

NMP: N-methyl-2-pyrrolidone

GBL: γ-butyrolactone

BCS: Butyl cellosolve

4.2. Evaluation method of liquid crystal structure stabilizer

The evaluation method for implementing the liquid crystal structure stabilizer is as follows.

<Viscosity measurement>

The viscosity of the polyamic acid solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL, a cone rotor TE-1 (1°34', R24), and a temperature of 25°C. .

<Measurement of imidization rate>

The imidization rate of polyimine is measured as follows.

Put 20 mg of polyimide powder into the NMR sample tube, and add _{0.53 ml of deuterated dimethyl sulfide (DMSO-d 6} , 0.05% TMS mixture) to completely dissolve it. This solution was used to measure proton NMR at 500 MHz with an NMR analyzer (JNM-ECA500) manufactured by JEOL Datum Ltd..

The imidization rate is calculated by the following formula. In addition, the imidization rate of the polyimide that does not use the diamine represented by the formula (1) is based on the value of the "introduction amount of the diamine of the formula (1) during the polymerization of polyamide acid" in the following formula Calculate for zero.

The imidization rate (%)=(100-the introduction amount of diamine of formula (1) during polymerization of polyamide acid (mol%)/2)×α

In the formula, α is determined based on the proton derived from the structure unchanged before and after the imidization, using the peak cumulative value of the proton and the NH group derived from the amide acid appearing near 9.5 to 10.0 ppm. The cumulative value of the proton peak is calculated by the following formula.

α=(1-α‧x/y)

In the above formula, x is the peak cumulative value of the proton derived from the NH group of the amide acid, y is the cumulative peak value of the reference proton, and α is relative to the case of polyamide acid (the imidation rate is 0%). The ratio of the number of standard protons to one NH proton of the amide acid.

4.3. Preparation of stabilizer for liquid crystal structure Example 1 Synthesis example 1

In a 300ml 4-necked flask equipped with a nitrogen introduction tube and a stir bar, weigh DA-1 (4.87g: 45.00mmol) and DA-8 (1.88g: 5.00mmol), add 122.5g of NMP, and place it under a nitrogen atmosphere. Stir to completely dissolve. The solution was cooled to below 10°C, TC-2 (14.86g: 49.50mmol) was added, and after stirring for 30 minutes, the temperature was raised to 40°C, and the reaction was carried out for 24 hours in a nitrogen environment to obtain a polyamide acid solution (hereinafter PAA- 1).

In a 500ml Erlenmeyer flask, weighed 100g of PAA-1, add 130.77g of NMP, acetic anhydride (35.43g: 347.00mmol), pyridine (16.48g: 208.20mmol), and stir at room temperature for 30 minutes. , React at 45°C for 3 hours. After the reaction was completed, the reaction solution was poured into the cooled 1000 ml of methanol while stirring to precipitate a solid. The obtained solid was recovered by filtration, and then stirred and washed twice with 500 ml of methanol, and then vacuum-dried at 100°C to obtain white solid soluble polyimide (SPI-1). Polyimine The conversion rate was 87%, and the weight average molecular weight was 32,000.

In a 300-ml Erlenmeyer flask equipped with a stir bar, weigh 5.00 g of SPI-1 obtained by the above operation, add 45.00 g of GBL, and stir at 50°C for 16 hours to completely dissolve it. NMP16.67g, BCS16.67g, Ad-1 (0.50g: 10% by mass relative to SPI-1) were added to this solution, and stirred at room temperature for 24 hours to obtain the liquid crystal structure stabilizer used in the present invention (Following AL-1).

Example 2 Synthesis Example 2

In a 200ml 4-necked flask equipped with a nitrogen introduction tube and a stir bar, weigh DA-3 (2.93g: 24.00mmol), DA-5 (6.50g: 32.00mmol), and DA-6 (7.02g: 24.00mmol). ), add 129.70g of NMP, and stir in a nitrogen environment to completely dissolve. Cool the solution to below 10°C, add TC-3 (5.23g: 24.00mmol), stir for 30 minutes to make the reaction, add TC-1 (10.75g: 54.80mmol), return to room temperature, and proceed under nitrogen It reacted for 24 hours to obtain a polyamide acid solution (hereinafter PAA-2).

In a 300 ml Erlenmeyer flask equipped with a stir bar, weigh 150.0 g of the PAA-2 obtained above, add 185.7 g of NMP to dilute, add acetic anhydride (23.30 g: 228.3 mmol) and pyridine (10.00 g: 126.37 mmol), After stirring at room temperature for 30 minutes, the temperature was raised to 50°C and the reaction was carried out for 3 hours. After the reaction was completed, the reaction solution was poured into the cooled 1000 ml of methanol while stirring to precipitate a solid. The solid recovered by filtration The body was further stirred and washed twice with 500 ml of methanol, and then vacuum-dried at 100°C to obtain an orange solid soluble polyimide (SPI-2). The obtained polyimide had an imidization rate of 85% and a weight average molecular weight of 37,000.

In a 300 ml Erlenmeyer flask equipped with a stir bar, weigh 5.00 g of SPI-2 obtained by the above operation, add 45.00 g of GBL, and stir at 50° C. for 16 hours to completely dissolve. NMP16.67g, BCS16.67g, Ad-1 (0.50g: 10% by mass relative to SPI-2) were added to this solution, and stirred at room temperature for 24 hours to obtain the liquid crystal structure stabilizer used in the present invention (Following AL-2).

Example 3 Synthesis Example 3

In a 200ml 4-necked flask equipped with a nitrogen introduction tube and a stir bar, weigh DA-4 (1.95g: 16.00mmol), DA-5 (8.13g: 40.00mmol), and DA-7 (9.78g: 24.00g). ), add 143.00g of NMP, stir at 50°C in a nitrogen environment to completely dissolve. TC-3 (2.62g: 12.00mmol) was added to the solution, and after stirring for 30 minutes to make the reaction, TC-1 (13.26g: 67.60mmol) was added, returned to room temperature, and reacted for 24 hours under a nitrogen environment to obtain Polyamide acid solution (hereinafter PAA-3).

In a 300 ml Erlenmeyer flask equipped with a stirring bar, weigh 150.0 g of the PAA-3 obtained above, add 278.6 g of NMP for dilution, and add acetic anhydride (20.78 g: 203.50 mmol) and pyridine (8.91 g: 112.61). mmol), after stirring at room temperature for 30 minutes, the temperature was raised to 50°C, and the reaction was carried out for 3 hours. After the reaction was completed, the reaction solution was poured into the cooled 1000 ml of methanol while stirring to precipitate a solid. The obtained solid was recovered by filtration, and then stirred and washed twice with 500 ml of methanol, and then vacuum-dried at 100°C to obtain an orange solid soluble polyimide (SPI-3). The obtained polyimide had an imidization rate of 83% and a weight average molecular weight of 32,000.

In a 300 ml Erlenmeyer flask equipped with a stir bar, weigh 5.00 g of SPI-3 obtained by the above operation, add 45.00 g of GBL, and stir at 50° C. for 16 hours to completely dissolve. NMP16.67g, BCS16.67g, Ad-1 (0.50g: 10% by mass relative to SPI-3) were added to this solution, and stirred at room temperature for 24 hours to obtain the liquid crystal structure stabilizer used in the present invention (Following AL-3).

Example 4

In a 100ml Erlenmeyer flask equipped with a stir bar, weigh the AL-2 (25.0g) and AL-3 (25.0g) obtained in Example 2 and Example 3, and stir at room temperature for 24 hours to obtain the use of the present invention. Liquid crystal structure stabilizer (hereinafter AL-4).

Example 5 Synthesis Example 4

In a 200 ml 4-necked flask equipped with a nitrogen introduction tube and a stir bar, weigh DA-8 (1.13 g: 3.00 mmol) and DA-9 (7.73 g: 27.00). mmol), add 109.60g of NMP, and completely dissolve in a nitrogen environment. The solution was cooled to 10°C or lower, TC-3 (6.09 g: 27.9 mmol) was added, and the reaction was returned to room temperature for 24 hours under a nitrogen environment to obtain a polyamide acid solution (hereinafter PAA-4). The weight average molecular weight of the obtained PAA-4 was 31700.

In a 300 ml Erlenmeyer flask equipped with a stir bar, weigh 100 g of the PAA-4 obtained above, add 40.00 g of NMP, 60.00 g of BCS, and Ad-1 (1.20 g: 10% by mass of the solid content of PAA-4). Stirring was performed at room temperature for 24 hours to obtain a liquid crystal structure stabilizer (hereinafter AL-5).

Comparative example 1 Synthesis Example 5

DA-2 (11.76g: 59.3mmol) was weighed in a 200ml 4-necked flask equipped with a nitrogen introduction tube and a stir bar, NMP65.80g and GBL65.80g were added, and it was completely dissolved in a nitrogen atmosphere. Cool the solution to below 10°C, add TC-3 (6.47g: 29.65mmol), stir for 30 minutes to make the reaction, add TC-1 (5.00g: 25.50mmol), return to room temperature, and proceed under nitrogen It reacted for 24 hours to obtain a polyamide acid solution (hereinafter PAA-5). The weight average molecular weight of the obtained PAA-5 was 29,000.

In a 300 ml Erlenmeyer flask equipped with a stir bar, weigh 100 g of the PAA-5 obtained above, add 112.50 g of GBL and 37.50 g of BCS, and stir at room temperature for 24 hours to obtain a liquid crystal structure stabilizer (hereinafter AL- 6).

Comparative example 2

Among the liquid crystal structure stabilizers obtained in the process of Synthesis Example 1, a liquid crystal structure stabilizer AL-7 which is a comparative object was obtained by preparing a liquid crystal structure stabilizer AL-7 that was not added with Ad-1.

Comparative example 3

In a 100 ml Erlenmeyer flask equipped with a stir bar, weigh AL-1 (20.0 g) obtained in Example 1 and AL-4 (80.0 g) obtained in Example 4, and stir at room temperature for 24 hours to obtain The liquid crystal structure stabilizer for comparison (hereinafter AL-8).

The following table shows the composition of the polymer prepared in the above synthesis example and the composition of the liquid crystal structure stabilizer.

5. Modulation and evaluation of stabilizing film of liquid crystal structure <Measurement of Roughness of Stabilizing Film of Liquid Crystal Structure>

After filtering the liquid crystal structure stabilizer with a 1.0 μm filter, it is placed on a substrate with electrodes (a glass substrate with a size of 30 mm in width × 40 mm in length and a thickness of 1.1 mm. The electrodes are rectangular with a width of 10 mm × 40 mm in length, and An ITO electrode with a thickness of 35 nm) was applied by spin coating. After spin coating, it was left for 5 minutes at a room temperature of 23°C and a humidity of 50%, and fired in an IR oven at 220°C for 20 minutes to obtain a substrate with a liquid crystal structure stabilizer film. After rubbing the stabilized film of the liquid crystal structure with rayon cloth (Yoshikawa Chemical YA-20R) (roller diameter: 120mm, roller rotation number: 700rpm, moving speed: 50mm/sec, press-in length: 0.2mm), The pure water is irradiated with ultrasound for 1 minute for washing, and the water is removed by blowing After dropping, drying was performed at 80°C for 15 minutes to obtain a substrate with a liquid crystal structure stabilizing film. The uniformity of the obtained film was subjected to surface analysis using DFM (Direct Force Atomic Force Microscope: manufactured by Hitachi High-Technologies), and the roughness per 10 μm was calculated and compared. The smaller the roughness, the better the uniformity or film-forming properties of the film.

<Production of substrate with stabilizing film of liquid crystal structure>

After filtering the liquid crystal structure stabilizer with a 1.0 μm filter, apply it to a substrate with electrodes (a glass substrate with a size of 30 mm in width × 40 mm in length and a thickness of 1.1 mm. The electrodes are rectangular with a width of 10 mm × 40 mm in length, and An ITO electrode with a thickness of 35 nm) was applied by spin coating. After drying for 1 minute on a hot plate at 80°C, it was fired in an IR oven at 220°C for 20 minutes to form a coating film with a thickness of 100 nm to obtain a substrate with a liquid crystal structure stabilizing film. After rubbing the stabilized film of the liquid crystal structure with rayon cloth (Yoshikawa Chemical YA-20R) (roller diameter: 120mm, roller rotation number: 700rpm, moving speed: 50mm/sec, press-in length: 0.2mm), The pure water was irradiated with ultrasonic waves for 1 minute for cleaning, and the water droplets were removed by air blowing, and then dried at 80°C for 15 minutes to obtain a substrate with a liquid crystal structure stabilized film.

6. Production and evaluation of liquid crystal cell

Prepare two substrates with the liquid crystal structure stabilizer film mentioned above. On the liquid crystal structure stabilizer film of one of the substrates, a sealant mixed with 6.0 μm or 4.0 μm spacer beads (XN-Kyoritsu Chemical Co., Ltd.) 1500T) use After dispensing and coating, the other substrate is bonded so that the liquid crystal structure stabilization film faces face each other and the alignment direction becomes 0°, and then the sealant is thermally cured to produce an empty cell.

The empty cell obtained as described above was placed on a hot plate heated to 80°C, and a liquid crystal for ULH mode manufactured by Merck was used. The liquid crystal was injected by capillary injection, and the injection port of the liquid crystal was sealed to form a crystal for ULH evaluation. Cell. The model diagram is shown in Figure 1.

<Observation of ULH initial alignment>

A polarizing microscope (POM) equipped with a heating and cooling stage was used to evaluate the alignment. Install the liquid crystal cell obtained as described above on the heating and cooling table, raise the temperature to the temperature at which the liquid crystal becomes the isotropic phase, and after confirming that the liquid crystal becomes the isotropic phase completely, apply 14Vp-p (cell gap 4.0μm) with the function signal generator. When the temperature is lowered to 50°C at a rate of 3°C/min, a rectangular wave AC voltage of 20Vp-p (with a cell gap of 6.0μm) can be converted to ULH. After reaching the ULH state, the voltage application was stopped, the room temperature was restored, the polarizing plate was brought into the state of crossed Nicols, the liquid crystal cell was rotated, and the initial alignment was evaluated by confirming the bright state and the dark state. The case where the alignment is good is shown in Fig. 2 and the case where the alignment is bad is shown in Fig. 3, and the evaluation results are as follows.

<Measurement of pretilt angle>

In addition, MLC-2041 manufactured by Merck, which is a liquid crystal for horizontal alignment, was injected by a vacuum injection method to form a unit cell for sealing the liquid crystal injection port. The measurement of the pretilt angle using the cell encapsulated with nematic liquid crystal was performed. The measurement was performed using an Axoscan Muller matrix polarizer manufactured by Axometrix.

In Examples 1 to 5, the liquid crystal structure stabilizing film prepared by the liquid crystal structure stabilizing agent containing polyamide acid or soluble polyimide with introduced side chains and additives that can improve friction resistance is used. After rubbing, there is no friction, cutting, dust, etc., showing very low roughness. In addition, when an alignment film with a small roughness is used, a good ULH alignment can be obtained. On the other hand, a polyamide-based material that does not contain a side chain as in Comparative Example 1 has a low roughness, but a good ULH alignment cannot be obtained. It can be seen that the soluble polyimide with side chain has significant significance on the alignment of ULH. In addition, although the soluble polyimide having a side chain was used in Comparative Example 2, there was no reinforcement by additives, and it was found that the roughness was increased due to the cutting during friction, and a good ULH alignment could not be obtained. In Comparative Example 3, it was a mixed material of polyamide acid and soluble polyimide, but as a result, unevenness was generated due to phase separation. The surface roughness becomes larger, and along with it, a good ULH alignment cannot be obtained. In the case of the embodiment, as shown in FIG. 2, the bright state and the dark state can be clearly observed, and it is confirmed that the ULH alignment is good. On the other hand, in the case of the comparative example, as shown in FIG. 3, even if the liquid crystal cell is rotated, the bright state and the dark state cannot be observed, and the ULH alignment is poor.

From this result, it was judged that the surface roughness after the rubbing treatment was small and the polyimide containing side chains was effective for the alignment of ULH.

[Industrial Utilization]

As described above, the liquid crystal display element manufactured using the liquid crystal structure stabilizer of the present invention is suitable for use in a large-screen, high-definition liquid crystal television with excellent display characteristics, electrical characteristics, and other performances.

Claims (8)

The use of a composition for forming a film for ULH alignment of cholesteric liquid crystals, characterized in that the composition contains polyamide acid containing a side chain structure, polyamide ester containing a side chain structure, and At least one polymer selected from the group of polyimides obtained by imidizing the aforementioned polyamide acid or polyamide ester amide, and an additive that can improve friction resistance. The use according to claim 1, wherein the aforementioned at least one polymer is polyamide acid which is a reaction product of a diamine component containing at least one diamine selected by the following formula and a tetracarboxylic dianhydride component , Polyurethane, or soluble polyimide,

(A ₁ is an alkyl group with 2-24 carbons or a fluorine-containing alkyl group, or a cholesterol group, and A ₂ is -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -, -NHCO-, -CONH- or -CH ₂ OCO-, A ₃ is a C 1-22 alkyl group, alkoxy group, fluorine-containing alkyl group, or fluorine-containing alkoxy group). The use according to claim 1 or 2, wherein the aforementioned additives that can improve friction resistance are selected from phenolic resin additives, amino plastic additives, epoxy additives, and acrylic additives It is a group consisting of agents, silane coupling agents, blocked isocyanate-based additives, and oxazoline-based compounds. The use according to claim 1 or 2, wherein the aforementioned at least one polymer contains a soluble polyimide having a imidization rate of 50% to 100%. The use of a film for ULH alignment of cholesteric liquid crystals, which is characterized in that the film contains a polyamide containing a side chain structure, a polyamide containing a side chain structure, and the aforementioned polyamide At least one polymer selected from the group of polyimides formed by acid or polyamide ester imidization, and additives that can improve friction resistance, and the average surface roughness Ra is 1.0 Below nm. The use according to claim 5, wherein the pretilt angle measured by using nematic liquid crystal of the aforementioned film is 3°-20°. The use according to claim 5 or 6, wherein the average surface roughness Ra of the surface after the alignment treatment of the aforementioned film is 1.0 nm or less. The use according to claim 7, wherein the aforementioned alignment treatment is performed by rubbing treatment using rayon or cotton that has been treated to reduce the abrasion of the cloth to impart uniaxial alignment of the liquid crystal.

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