JPS6036572B2 - Method for manufacturing alignment control film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display cell, and more particularly to a method for manufacturing an alignment control film for a liquid crystal display cell for improving viewing angle, contrast response, reliability, and the like.

The present invention relates to a nodal control film for a twist effect type liquid crystal display device using nematic liquid crystal.

Nematic liquid crystals are applied to electro-optic display devices by utilizing the optical changes that occur when an electric field is applied to them. Electro-optical display elements using nematic liquid crystals are
They are classified into two types depending on the dielectric anisotropy of the nematic liquid crystal used. One is to apply electrolysis to a nematic liquid crystal (hereinafter abbreviated as Nn-liquid crystal), which has a molecular dipole moment direction almost perpendicular to the long axis direction, that is, a nematic liquid crystal (hereinafter abbreviated as Nn-liquid crystal) that has negative dielectric anisotropy. Dynamic scattering mode (DSM) is a light scattering phenomenon caused by the collision between ions generated when the voltage is applied and a group of Nn-liquid crystal molecules.
This is a display element that utilizes. The other method is to apply an electric field to a nematic liquid crystal whose dipole moment direction is approximately in the same direction as the long axis of the molecules, that is, a nematic liquid crystal with positive dielectric anisotropy (hereinafter abbreviated as Np-liquid crystal). This is a display element that utilizes the so-called field effect mode (FFM), which is a change in the twist or tilt of Np-liquid crystal molecules that occurs when a voltage is applied. Many of the latter FFM liquid crystal display elements are so-called twist effect type display elements (hereinafter referred to as TN
(abbreviated as TN type display element), and the present invention relates to this TN type display element. A TN type display element is a cell in which a pair of transparent electrode plates are formed by applying a transparent conductive coating to one side of a support such as a glass plate and used as electrode surfaces so that the electrode surfaces face each other to form a cell, and Np-liquid crystal is injected into the cell. Created by filling. In this case, the electrode surfaces are processed in advance with a certain directionality by an oblique evaporation method, a wrapping method, etc., and the electrode plates are stacked at appropriate intervals with the electrode surface processing directions substantially perpendicular to each other. In the TN type display element obtained in this way, the long axis of the Np liquid crystal molecules is oriented on each electrode surface almost parallel to the electrode surface and in the same direction as the electrode surface processing direction, and the Np liquid crystal molecules are continuous between the electrode surfaces. It is oriented with a twist of approximately 90 degrees.

The polarization plane of the linearly polarized light that is perpendicularly incident on the electrode plate is rotated approximately 90 degrees while passing through the TN type display element. Therefore, a TN-type display element is installed so that its optical vibration planes are parallel to each other, and the light is blocked between two polarizing plates, and the two polarizing plates are installed so that their optical vibration planes are perpendicular to each other. Electricity and light pass between the plates. When a voltage is applied to this TN type display element, N
P- liquid crystal molecules have their long axes aligned in the direction of the curve in response to applied pressure, and above a certain voltage value, the Np-liquid crystal molecules have their longest axes aligned substantially parallel to the direction of the curve. When a voltage is applied, the TN-type display element transmits light between the parallel polarizing plates and blocks light between the orthogonal polarizing plates, completely opposite to when no voltage is applied. In this way, by sandwiching the TN-type display element between two polarization slopes, it changes from a light-blocking state to a light-transmitting state, or from a light-transmitting state to a light-blocking state, depending on the applied voltage. Light modulation is used for display.

A TN-type display device consisting of a TN-type display element and a drive circuit supported by two polarizing plates is applied to displays in various measuring instruments such as electronic desktop calculators, electronic clocks, and electronic computers.

Conventionally known liquid crystal alignment control films used in TN display devices include silicon dioxide films, thermosetting resin films such as polyimide, and photocurable resin films such as polyvinyl alcohol.

Silicon dioxide requires a complex and expensive thin film production process such as an oblique evaporation method, and also has the disadvantage that the orientation of the liquid crystal is inferior to liquid crystals that operate at relatively low voltages such as azoxy liquid crystals. On the other hand, organic films such as polyimide have drawbacks such as requiring a long heat curing process at high temperatures after coating the resin, and poor adhesion to glass, which is commonly used for substrates. Furthermore, in order to meet the unique requirements of liquid crystal display devices in which electrical connections are made in some parts of the facing transparent conductive films, a process of partially peeling off the alignment control film by plasma treatment or chemical treatment is necessary. , had to perform extremely complicated work. On the other hand, although photocurable resin films such as polyvinyl alcohol do not have the above-mentioned drawbacks, they have low heat resistance during rubbing treatment, and the curing temperature of adhesives used to assemble liquid crystal display cells is limited.

For this reason, it has been difficult to bond two substrates together using epoxy resin, which has excellent adhesive strength. SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to provide a method for manufacturing an alignment control film that is extremely easy to manufacture, inexpensive, and has high performance.

To achieve this purpose, a photocurable polymer film is coated on the substrate and electrodes, and after semi-curing, a mask with a predetermined pattern is attached to it, and then ultraviolet or visible light is applied. Alternatively, after the resin is sufficiently cured by irradiation with radiation, the uncured (unexposed) portion is removed by dissolving it with a solvent, and the photocured film is wrapped in a predetermined direction, or the photocured film is heated further to 200°C. After heating to the above temperature, the thermosetting film is then subjected to wrapping treatment in a predetermined direction to produce an orientation control film.

Note that a liquid crystal display cell is manufactured by sealing a pair of substrates having an alignment control film with an organic or inorganic sealant and sealing liquid crystal therein. The base resin of the photocurable polymer used in the present invention is polyimide-based resin such as polyimide, polyimide silicone, polyester imide, polyamide-imide, polyimide-isoindroquinazolinedione, polyimide-imidazopyrrolone, and polyisoindroquinazolinedione-based resin. These are resins, polyisoindrobenzothiadiazine dioxide-based resins, polyimidazopyrrolone-based resins, and polybenzooxidinone-based resins.

Specifically, the photocurable polymer is manufactured into an alignment control film in the following order. 1 Polyimide resin B Polyisoindoquinazolinedione M Polyisoindorobenzothiazine dioxide W
Polyimidazopyrrolone V Polybenzoxazinone (However, in the formula, R is a divalent group containing at least 2 carbon atoms, and in the formula, the two amino groups of the diamine component are each a divalent group. Assume that they are bonded to distant carbon atoms.

R2 is a tetravalent group containing at least 2 carbon atoms. R3, R4 are trivalent groups having at least 3 carbon atoms, each of the three amino groups is bonded to a separate carbon atom, and two of the amino groups are bonded to adjacent carbon atoms. ing. R5, R6, R7, R8
is a tetravalent group having at least 4 carbon atoms,
The bonds of the groups are mutually bonded to adjacent carbon atoms. R9 is, Z is an alkylene group, 10-, 1NHCO-, 1S, 1S
Any substance that can connect aromatic nuclei such as 02-, 1COO-, etc. may be used.

× is CO or S02. Y is hydrogen or COR', and R' is an alkyl group, an aryl group, an alkoxy group, or a phenoxy group. R″ is a photosensitive group and is represented by .

R'' is -CH2CH2-, and R''' is hydrogen or a methyl group.

R-types are hydrogen, alkyl, carbocyclic, heterocyclic, and aromatic residues.

) The diamine component used in the present invention is metaphenyl diamine, /f rough phenylene diamine, 4,4-diaminodiphenyl pro/gun 4,4-diaminodiphenylmethane, 4
, 4'-diaminodiphenyl sulfide, benzidine,
4,4'-diaminodiphenyl sulfone, 3,3-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 4,4-di(metaminophenoxy)diphenyl sulfone, 4,4' -di(para-aminophenoxy)diphenylsulfoso, 1,5-diaminonaphthalene, and 3,3-dimethyl-4,4'-pifhenyldiamine.

The diaminoamide compound used in the present invention has the following general formula (in the formulas 01 to t41, X is S02 or CO
and Z is ○, C(CH)2, S02, S, CO, etc.

The positions of one amine/group bonded to the aromatic nucleus and the XNH2 group are not limited as long as they are bonded to each other in the ortho position. Furthermore, the hydrogen atom bonded to the aromatic nucleus may be substituted with other inert groups such as an alkyl group, an aryl group, a halogen atom, or a nitro group). Specific examples of those shown are 4,4'-diaminodiphenyl ether-3-sulfonamide, 3,4'-diaminodiphenyl ether-4-sulfonamide, 3,4-diaminodiphenyl ether-3' -sulfonamide, 3,
3'-diaminodiphenyl ether-4-sulfonamide, 4,4'-diaminodiphenylmethane-3-sulfonamide, 3,4'-diaminodiphenylmethane-4-
Sulfonamide, 3,4'-diaminodiphenylmethane-3'-sulfonamide, 3,3'-diaminodiphenylmethane-4-sulfonamide, 4,4'-diaminodiphenylsulfone-3-sulfonamide, 3,4'- Diaminodiphenylsulfone-4-sulfonamide, 3,
4'-diaminodiphenyl sulfone-3'-sulfonamide, 3,3-diaminodiphenyl sulfone-4-sulfonamide, 4,4'-diaminodiphenyl sulfide-3-sulfonamide, 3,4'-diaminodiphenyl sulfonide Aido-4-sulfonamide, 3,3'-diaminodiphenylsulfaido-4-sulfonamide, 3
, 4'-diaminodiphenyl sulfide 3'-sulfonamide, 1,4-diaminobenzene-2-sulfonamide, 4,4-diaminodiphenyl ether-3-carbonamide, 3,4'-diaminodiphenyl ether-4-carbonamide, 3,4'-diaminodiphenyl ether-3-powerponamide, 3,3'-diaminodiphenyl ether-4-carbonamide, 4,4'-diaminodiphenylmethane-3-powerponamide, 3,4'-diaminodiphenyl ether-3-powerponamide enylmethane-4-carbonamide, 3,
4'-diaminodiphenylmethane-3-carbonamide, 3,3'-diaminodiphenylmethane-4-carbonamide, 4,4'-diaminodiphenyl sulfone-3-
carbonamide, 3,4'-diaminodiphenylsulfone-4-carbonamide, 3,4'-diaminodiphenylsulfone-3'-carbonamide, 3,3-diaminodiphenylsulfone-4-carbonamide, 4,4'
-diamin/diphenylsulfide-3-carbonamide, 3,4-diaminodiphenylsulfide-4-carbonamide, 3,3'-diaminodiphenylsulfide-4-carbonamide, 3,4-diaminodiphenylsulfide-3 '-sulfonamide or 1,4
-Diaminobenzene-2-carbonamide, etc.
The triamine compound used in the present invention has the general formula (wherein R
4 is a trivalent group having at least 3 carbon atoms, and Y is an alkyl group, an aryl group, an alkoxy group, or a phenoxy group. ), where R
4 is aromatic, aliphatic, alicyclic, heterocyclic, or a combination thereof, or these are oxygen, nitrogen,
Trivalent residues such as those bonded with sulfur, silicon, phosphorus, etc. are preferred, and among these, those with a structure exhibiting aromaticity are particularly preferred. In this case, the aromatic ring may include a hydroxyl group, an alkyl group, a cycloalkyl group, an allyl group, an alkoxy group, a cycloalkoxy group, an allyloxy group, a halogen, or the like. This is because, in some cases, these substituents significantly improve the favorable adhesive properties of the resulting poly(imidazohyloronimide) and the like. The structures of these preferred triamines are shown below. (However, in the formula, Z,
Z is an alkylene group having 1 to 3 carbon atoms, 10-
, one S-, one S02, one CO-, one CONH-.

Furthermore, two of the three amino groups must be bonded to each other in ortho positions.

The other one may be placed in any position. ) Triamines suitable for carrying out the reaction are shown below with specific compound names. 3,4,4 triamino diphenyl ether, 3,4,4' triamino diphenylmethane, 3,4,4 triamino diphenylpropane, 1,2,4 triamino diphenyl, 2,4, 5
-Triaminotoluene, 3,4,4' triaminodiphenyl sulfone, 3-amino-penzidine, 5-aminodianisidine, 3,3-dichloro-5-aminopenzidine, 3,3-dimethyl-5-amino benzidine,
3,4,4-triaminodiphenylene sulfide,
3,4,3' triamino diphenyl sulfone, 3,
4,4-triaminodiphenyldiethylsilane, 3,4
, 4'-triaminobenzanilide, 1,3,4-triaminomicrohexane, 2,3,6-triaminopyridine, 1,2,5-triaminonaphthalene, 3,4,4
These triamines such as '-triaminodicyclohexylmethane can be used alone or in combination as appropriate.

The acylaminodiamine used in the present invention is a compound represented by the above general formula, and examples of preferred structures of amylaminodiamine are as follows.

(However, in the formula, Z2 and Z3 are alkylene groups having 1 to 3 carbon atoms, 10-, 1S-, 1SQ-, -CO-
, -CONH-, and R is a monovalent substituent consisting of an alkyl group, a cycloalkyl group, or an aryl group.

Further, one amino group and one amyl amino group must be bonded to each other in the ortho position. The other amino group may be located at any position. Specifically, 4-formamide-3,4'-diami/-diphenyl ether, 4-
Acetamide-3,4'-diamino-diphenyl ether, 4-benzamido-3,4-diamino-diphenyl ethane, 4-propionamido-3,4'-diamino-diphenylpro/g, 1-acetamido-2,4- Diaminobenzene, 4-formamido-2,4-diaminobenzene, 4-acetamido-2,4-diaminobenzene, 4-propionamido-3,4'-diaminodiphenyl sulfone, 3-chloroacetaminopenzidine, 4 -Acetamide 3,4'-diphenyl sulfide, 4-penzamido 3,4'-diaminodiphenyldimethylsilane These acylaminodiamines can be used alone or in combination. The diaminodiamide used in the present invention is a compound having two sets of amino groups and amide groups bonded to adjacent carbon atoms in one molecule.

The diamino diamide preferably used has the following structure. (In the formula, O is an alkylene group with a carbon-carbon bond that directly connects aromatic nuclei, 101,1S02-,S-,1CONday1,1COO
Any material that can connect aromatic nuclei such as -, etc. may be used. ) The diaminodisphonamide used in the present invention is a compound having two sets of amino groups and amide groups bonded to adjacent carbon atoms in one molecule. The diaminodisulfonamide preferably used is a compound having the following mechanism. (However, in the formula, carbon-carbon bond directly connecting aromatic nuclei, alkylene group, 10-, 1S02-, -S-, 1CONH-, 1CO
Any material may be used as long as it can connect aromatic nuclei such as O.

) Tetramines preferably used in the present invention have the following structures.

(In the formula, Z6 is an alkylene group with a carbon-carbon bond that directly connects aromatic nuclei, 10-,1S021,1S,1CON
Any material that can connect aromatic nuclei such as H-, 1-COO, etc. may be used. ) Furthermore, diamylaminodiamine having the following structure is particularly preferable. (however,
In the formula, Z is an alkylene group with a carbon-carbon bond that directly connects aromatic nuclei, 10-, 1S02 1, -S-, 1CONH
Any material that can connect aromatic nuclei such as - may be used.

R' is a monovalent substituent consisting of an alkyl group, a microalkyl group, or an aryl group. The diaminodicarboxylic acid compound used in the present invention preferably has the following structure.

(In the formula, Z is -○-, -S-, -S02-, -CO-,
- Represents OAv○-. Ay represents a phenylene, diphenylene, naphthalene group, or

) Also, carboxylic dianhydrides are, for example, pi.

Mellitic acid dianhydride, 2,3,6,7 naphthalene tetracarboxylic dianhydride, 3,3',4,4'-tetracarboxybiphenyl dianhydride, naphthalene-1,2,4
, 5-tetracarboxylic dianhydride, pyridine-2,3,
5,6-tetracarboxylic dianhydride, 3,3',4,4
'-benzophenonetetracarboxylic dianhydride 1,4,
5,8 naphthalenetetracarboxylic dianhydride, 3,4
, 9,10-berylenetetracarboxylic dianhydride, 4,4'-sulfonyl diphthalic dianhydride, and mixtures thereof may be used as appropriate. Further, the compound having a photosensitive group used in the present invention has the following structure. (However, in the formula, R2 is a tetravalent group containing at least 2 carbon atoms.

X, is a halogen atom of CI, By. R'' is the photosensitive group described above. ) In the practice of this invention, inert solvents are used.

Preferably, it has the effect of melting the produced polymer intermediate. For example, N-methyl-2-pi. Lydone, N,N'-dimethylacetamide, N,N'
One or more of monodimethylformamide, N,N'-diethylformamide, dimethyl sulfoxide hexamethylphosphoramide, tetramethylene sulfone, etc. can be used. Further, a small amount of naphtha or the like can be added to these inert solvents in order to adjust the viscosity of the solution.

Furthermore, lithium chloride, magnesium chloride, etc., which have been conventionally used to facilitate the dissolution of resinous materials, can be added to the inert solvent.

In the embodiment of the present invention, solution polycondensation is preferred, but is not particularly limited.

Namely, diamine, diaminoamide, diaminosulfonamide, triamine, amyl aminodiamine, diaminodiamide, dianodisulfonamide, tetraamine,
Diamylaminodiamine, tetracarboxylic dianhydride, a tetracarboxylic acid derivative having a photosensitive group, diaminodicarboxylic acid and its derivative, or dicarboxylic acid dichloride are dissolved as well as possible in the inert solvent, and the reaction is carried out. The system is maintained at a temperature of about 80 qo or less, especially near or below room temperature. As a result, the reaction proceeds rapidly, and the viscosity of the reaction system gradually increases, producing a polymer varnish.

Next, as a monoepoxy compound used in the present invention,
etc.

In the addition reaction between a carboxyl group and an epoxy group in the present invention, tertiary amines such as trimethylamine, triethylamire, N-N-dimethylaniline, N,N-diethylaniline, and triethylamire hydrochloride, and secondary amines such as diethylamine hydrochloride are used. Alkali metal chlorides such as amines, tetraethylammonium chloride, triethylbenzylammonium chloride, quaternary ammonium salts such as dotesyltriethylammonium iodide, potassium benzoate, sodium acetate, lithium chloride, etc. are used as catalysts. .

In an embodiment of the photocurable polymer of the present invention, a monoepoxy compound is well dissolved in the above polymer intermediate, and the reaction system is controlled in the presence of a catalyst such as a tertiary amine, a quaternary ammonium salt, or an alkali metal salt compound. It is added almost quantitatively at a reaction temperature of about 70 to about 13,000 ℃ to give the desired photocurable polymer intermediate.

By adding a photosensitizer to the obtained photocurable polymer, it can be used as it is as a photocurable polymer.

Examples of the photosensitizer used in the present invention include benzophenone, acetophenone, anthrone, P,P-tetramethyldiaminobenzophenone (Michler's ketone), phenanthrene, naphthalene, 2-nitrofluorene, 5-nitroacenaphthene, N-acetyl-4 -Nitro-1-naphthylamine, 4-nitro-1-naphthylamine, benzoquinone, dibenzalacetone, benzyl, P-diaminobenzophenone, P,P'-dimethyl-aminobenzophenone, 1,2-naphthoquinone, 1,4-naphthoquinone , anthraquinone, and 1,9-penzoanthrone are used alone or in combination.

These photosensitizers have approximately 0
．． It is added in a proportion of 0.01 to 1% by weight, and the amount is increased as appropriate when a coloring agent such as a pigment is added. The present invention will be explained below with reference to Examples. The above-mentioned photocurable polymer is stable in the state in which a photosensitizer is added, and its stability varies depending on the type of curable component, but it remains stable for many months when stored at room temperature and protected from light. It is.

Photocuring is carried out by irradiation with light, generally ultraviolet rays, visible light, electron beams, radiation, etc., and even when a colorant that delays curing is added, curing is usually completed within 2 minutes. Next, the resin in the photocured portion is removed by dissolving or peeling off with an organic solvent, and then the photocured polymer film is heated at a temperature of about 100 to 350°C. The present invention will be explained below with reference to Examples.

Example 1 A. In a 300mm 4-necked flask equipped with a thermometer, a stirrer, a calcium chloride tube, and a nitrogen introduction tube, 4,4
Add 15 moles of '-diaminodiphenyl ether (0.075 mol), 100 moles of N-methylpyrrolidone and 100 moles of dimethylacetamide, stir the contents well,
dissolve.

After the contents have dissolved, the flask is cooled in an ice bath, and 24.16 mol (0.075 mol) of pyromellitic dianhydride is gradually added, and after the addition is complete, the reaction is carried out at 15°C for 6 hours. (b) After that, it was heated to 90 oo while flowing nitrogen gas, and 3.78 glycidyl cinnamate was added to the obtained polyamic acid varnish.
0 and triethylbenzylammonium chloride
．． Add 378 hours and react for 90 hours. A sensitizer P,P'-tetramethyldianobenzophenone was added to the resulting photocurable polyamic acid varnish, which was applied to the glass plate shown in the figure, dried for 80q03 minutes, and a predetermined pattern was drawn on this substrate. Attach a mask and expose the board to a high-pressure mercury lamp (
30 arc/IKW) for 60 seconds. Then,
After sufficiently dissolving the uncured resin in the unexposed areas on the substrate with N-methylpyrrolidone, it is dried at 80 qo for 30 minutes. Further, this substrate was heated and cured for 350,002 hours.
The thin resin film created as described above is rubbed in a certain direction with felt to complete an orientation control film.

The orientation control films of the two completed plates were placed in parallel and facing each other, and these plates were adhered with a sealing agent made of a frit glass sealant (amorphous frit glass) to create a cell. Note that the sealant was air fired at 450 to 47,000 for 30 minutes. Biphenyl-based and ester-based liquid crystals are sandwiched between the alignment control films of this cell, and a polarizing plate is placed parallel to the surface of the cell's glass substrate that does not have the alignment control film. When examined, it showed good orientation. In addition, the pattern accuracy is 5 to 30y,
It had good heat resistance. Example 2 Table No. An alignment control film was prepared using the photocurable polymers Nos. 2 to 7 in the same manner as in Example 1.

The orientation, pattern accuracy, and heat resistance of the film were all good as shown in the table. As shown in the comparative example table, an orientation control film was prepared using conventional epoxy acrylate, but as shown in the table, good results were not obtained.

[Brief explanation of the drawing]

The figure is a cross-sectional view of a liquid crystal display cell. DESCRIPTION OF SYMBOLS 1... Glass substrate, 2... Transparent conductive film, 3... Alignment control film, 4... Liquid crystal, 5
...Organic or inorganic sealant, 6...Polarizing plate.

Claims (1)

[Claims] 1. An electrode is provided on the side of the liquid crystal holding substrate that is in contact with the liquid crystal, and a photocurable polymer film is applied over the substrate and the electrode, semi-cured, and a mask with a predetermined pattern drawn on the semi-cured film. It is characterized by attaching the film, irradiating it with ultraviolet rays, visible light, or radiation, then removing the uncured resin in the unexposed areas by dissolving or peeling it off with an organic solvent, heating the photocured polymer film, and wrapping it. A method for manufacturing an alignment control film.