JPS59200216A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To easily obtain a liquid crystal display element reduced in weight and thickness by using a specified aromatic polyetheresteramide polymer for an orientation control film material and making it possible to obtain said film at low temp. in a short time. CONSTITUTION:A material to be used as an orientation control film is an aromatic polyetheresteramide polymer having repeating units of formulae I and IIin which R1-R4 are each H, lower alkyl, lower alkoxy, Cl, or Br; R5, R6 are each H, methyl, ethyl, propyl, CF3, or CCl3; Ar, Ar' are each p-phenylene, m- phenylene, diphenylene, naphthylene, or the like; and X is a 2-10C aliphatic group optionally having an ether bond or the same as Ar'. The orientation control film is obtained at low temp. in a short time only by evaporating and drying a solvent after coating a substrate with a soln. of this polymer, thus permitting extremely easy and inexpensive fabrication of a liquid crystal display element, as compared with the conventional processes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display element using a specific alignment control film.

BACKGROUND ART Conventionally, transparent conductors for liquid crystal display devices have been made of glass whose surface is made transparent and conductive. However, liquid crystal display elements are becoming increasingly lighter and thinner. In response to these demands, the glass plate with a transparent conductive surface cannot be made thinner than a certain level due to the mechanical strength of the glass and manufacturing constraints, and the limit is said to be 3mm. There is. Therefore, there are limits to its applicability to the above-mentioned purposes, and furthermore, there is a problem that the device may be damaged during the process of preparing the device due to its vulnerability to impact. As a way to satisfy these shortcomings,
It is conceivable to use resin instead of conventional glass. However, as described above, in order to make the alignment of the liquid crystal uniform, an additional layer is required to control the alignment. In the case of conventional glass, the method of obtaining a layer for controlling this orientation is as follows.

A method of obliquely depositing a thin film made of an inorganic compound such as silicon dioxide, and a method of rubbing a thin film made of an organic compound such as polyimide (rubbing in a fixed direction with a cloth or the like) are known. However, all of the above methods require high temperature treatment during film formation. These problems are not a particular problem in conventional glass substrates, but in the case of resin substrates, the substrates cannot withstand the above-mentioned processing temperatures and deform, making it impossible to obtain a normal liquid crystal display element.

For example, if a resin film with transparent indium oxide electrodes is used and a polyimide resin is applied to the electrode side, the resin film substrate will undergo thermal deformation due to long-term heat treatment at high temperatures, resulting in a normal liquid crystal element. can't get it. Therefore, if the polyimide is heat-treated at a temperature lower than the heat deformation temperature of the resin film substrate (100°C), the heat curing reaction of the polyimide will be insufficient, and the rubbing process will fail.

There is a problem in that scratches or film peeling occur.

Therefore, after coating the resin film, a thermoplastic resin that does not require a curing reaction, that is, an organic solvent solution of polystyrene, polymethacrylate, polysulfone, polyethersulfone, polycarbonate, etc., is coated on the resin film and dried, and then subjected to a prescribed rubbing process. When we attempted to form a liquid crystal element by applying this method, we were unable to align the liquid crystal display element.

None of these resins could be used as an alignment control film for liquid crystals. As a result of investigating the cause of this, it was found that these resins dissolve in the liquid crystal, and the effect of the rubbed surface disappears.

Therefore, we investigated polyvinyl alcohol and various celluloses as resins insoluble in liquid crystals. That is,
These resins were dissolved in water, the aqueous solution was applied to the resin film, dried, and rubbed, and then the device was assembled. As a result, it was found that the liquid crystal molecules were well aligned to form a liquid crystal alignment control film. However, upon detailed examination, it was found that the device had poor moisture resistance reliability and alignment defects due to moisture occurred.

In other words, resin film has greater moisture permeability than glass plate buttons, so moisture can get into the element. However.

Because these alignment control films are water-soluble resins.

It is thought that the ability to orient liquid crystals was lost due to dissolution or swelling caused by water.

Furthermore, JP-A No. 55-9518 discloses a liquid crystal display panel that uses a polymeric substance (such as nylon) having an amide bond as an alignment treatment film, but this method requires the preparation of an alignment control film material solution. Each operation must be carried out at a considerably high temperature, which is not always satisfactory.

The present invention solves these problems.

That is, in the present invention, the alignment control film of a liquid crystal display element has the following formulas: (1) and (Ill) [However, in general formulas (1) and (If)
11R21R3 and R4 represent hydrogen, lower alkyl group, lower alkoxy group, chlorine or bromine, and they may be the same or different from each other, R5 and R6 represent hydrogen, methyl group, ethyl group, propyl M, tri 7 Indicates a fluoromethyl group or trichloromethyl group.

They can be the same and β different from each other.
Ar and Ar' are p-phenylene groups 1m-7e=v
group, diphenylene group, naphthylene group or H3, which may be the same or different from each other, X is an aliphatic group having 2 to 10 carbon atoms which may contain an ether bond, or the same group as Ar' The present invention relates to a liquid crystal display element comprising an aromatic polyether ester amide polymer having a repeating unit represented by the following.

The above aromatic polyether ester amide polymer is insoluble or poorly soluble in liquid crystals and water, and this polymer is dissolved in a specific solvent and applied to a substrate having a transparent conductive film such as indium oxide. , low temperature (100-120°C)
After drying with heat, obtain an orientation control film by rubbing. By arranging the alignment control films of the two substrates prepared in this way in parallel and facing each other, and sealing the liquid crystal between them, we were able to complete a resin-based liquid crystal glowing hydrogen element with satisfactory characteristics. .

The liquid crystal display element of the present invention generally has good self-synchronization property of the liquid crystal, and also has good moisture resistance. Therefore.

Any conventionally known material may be used for the substrate material. For example, it is possible to apply a commercially available film or sheet made of epoxy acrylate, polyethylene terephthalate, etc. that has a transparent conductive film. Any tough film or sheet can be used as long as it has been treated to prevent it from being dissolved by the process, and is not particularly limited. Of course, in the present invention, a glass substrate may be used.

In the present invention, a specific aromatic boron is added to the substrate.
.

- after applying the thyl esteramide polymer solution.

Since it is sufficient to simply evaporate and dry the solvent, an alignment control film can be obtained at low temperatures and in a short time. For example, the film thickness to be formed is 50
Since it is very thin with a thickness of about 0 to 2000 λ, it can be sufficiently dried even at temperatures below the boiling point. Therefore.

Compared to the conventional method of obliquely depositing a thin film of silicon dioxide or the like on a substrate (mainly a glass plate) or the method of forming a polyimide film, a liquid crystal display element can be manufactured very easily and at low cost.

The aromatic polyether ester amide resin having repeating units represented by general formulas m and (II) in the present invention has general formulas (I[I) Ra R6R4 (however, in formula 9, La21 R31R41R5 and R
6 has the same meaning as in the above general formula (1)) General formula (IV) HOX NH2 (F/) [In the formula (1), X is p- Phenylene group + m-phenylene group, diphenylene group, naphthylene group.

+y-@-<However, here, Y is a bond.

2 to 10 carbon atoms, which may contain a carbon or ether bond
A compound represented by [representing an aliphatic group] and an aromatic dicarboxylic acid or its reactive acid derivative are subjected to known aromatic polymerization process such as solution polymerization, melt polymerization, or the method disclosed in JP-A No. 52-23198. It can be obtained by condensation polymerization using a method for producing polyamide.

Here, the compounds represented by general formula (III) and general formula (IV) are preferably blended in a 9 molar ratio of 515 to 9/1, particularly 6/9 to 8/2. Preferably, it is blended. If this ratio is too small, heat resistance tends to decrease, and if this ratio is too large, adhesiveness tends to decrease.

Further, it is preferable to use 90 to 130 mol of the aromatic dicarboxylic acid or its reactive acid derivative based on the total amount of the compounds represented by the general formula (1) and the general formula (IV),
In particular, it is preferable to use 100 mol % or approximately 100 mol %.

In the present invention, the aromatic diamine having an ether bond represented by the general formula (III>) includes 2.2-bis(4-(4-aminophenoxy)phenyl)propane, 2.2-bis[3-methyl -4-(4-aminophenoxy)phenyl]propane, 2+2-bis[3-chloro-4-(4-aminophenoxy)phenyldifuropane,
2,2-bis[3-bromo-4-(4-aminophenoxy)phenyldifuropane, 2,2-bis[3-ethyl-
4-(4-aminophenoxy)phenyl]propane, 2
, 2-bis[3-propyl-4-(4-aminophenoxy)phenyl]propane, λ2-bis[3-isopropyl-4-(4-aminophenoxy)phenyl]propane, 2,2-bis[3-butyl -4-(4-aminophenoxy)phenyldifuropane, 2,2-bis[3-5ec
-butyl-4-(4-aminophenoxy)phenyl]propane + 2.2-hyx[3-me)xy-4-(4-aminophenoxy)phenyl]propane, 212-bis[3
-ethoxy-4-aminophenoxy)phenyl]propane, 2,2-bisC3,5-dimethyl-4-(4-aminophenoxy)phenyl]propane, 2+2-bis[
3,5-dichloro-4-(4-aminophenox7)phenyl]propane, 2+2-bis[3I5-dibromo-4
-(4-aminophenoxy)phenyl]propane.

2.2-bis[3,5-dimethoxy-4-(4-aminophenoxy)phenyl]propane, 2,2-bis[3-
Chloro-4-(4-aminophenoxy)-5-methylphenyl]propane, 1,1-his[4-(4-aminophenoxy)phenyl]ethane.

1.1-bis[3-methyl-4-(4-aminophenoxy)phenyl]ethane, 1.1-bis(3-chloro-4
-(4-aminoneenoxy)phenyl]ethane, l, 1
-bis[3-bromo-4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[3-ethyl-4-(4-aminophenoxy)phenyl]ethane, 1,1-his[3- 70 Biru-4-(4-aminophenoxy)phenyl]ethane.

1.1-bis[3-isopropyl-4-(4-aminophenoxy)phenyl]ethane, 1.1-bis[3-butyl-4-(4-aminophenoxy)phenyl]ethane,
1. l-Bis(3-5ec-butyl-4-(4-aminophenoxy)phenyl)ethane, 1,1-bis[3-methoxy-4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[ 3-ethoxy-4-(4-aminophenoxy)phenyl]ethane, L, 1-bis(3,5-
4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[3,5-dichloro-4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[3
15-dibromo-4-(4-aminophenoxy)phenyl]ethane, 1,1-bis(3,5-cymet#cy4-
(4-aminophenoxy)phenyl]ethane, 1,1
-Bis[3-chloro-4-(4-aminophenoxy)-
5-Methylphenyl]ethane.

Bis[4-(4-aminophenoxy)phenylcomethane, bis[3-methyl-4-(4-aminophenoxy)phenylcomethane, bis[3-chloro-4-(4-aminophenoxy)phenylcomethane, Bis[3-bromo-4
-(4-aminophenoxy)phenylcomethane, bis[
3-Ether-4-(4-aminophenoxy)phenylcomethane.

Bis[3-propyl-4-(4-aminophenoxy)phenylcomethane, bis[3-isopropyl-4-(4-
aminophenoxy) phenylcomethane, bis[3-butyl-4-(4-aminephenoxy)phenylcomethane,
Bis[3sec 7'f-4-(4-aminophenoxy7)phenylcomethane, bis[3-methoxy-4-(
4-aminophenoxy)phenylcomethane, bis[3-
Ethoxy-4-(4-aminophenoxy)phenylcomethane, bis[3,5-dimethyl-4-(4-aminophenoxy)phenylcomethane, bis[3,5-dichloro-
4-(4-aminoenoxy)phenylcomethane, bis[3,5-dibromo-4-(4-aminophenoxy)phenylcomethane, bis(3,5-dimethoxy-4-(4
-aminoneenoxy)phenyl]methane, bisC3-#
Loreau 4-(4-aminophenoxy)-5-methylphenylcomethane.

1,1.1.3.3.3-hexafluoro-2,2-bis[4-(4-aminophenoxy)phenyl]propane.

1,1.1.3.3.3-Hexachloro-2,2-bis[4-(4-aminophenoxy)phenyl]furopane.

3.3-bis(4-(4-aminophenoxy)phenyl]pentane, 1,1-bis[4-,(4-aminophenoxy)phenyl]propane, 1.1.1.3.3.
3-hexafluoro-42-bis(3,5-dimethyl-
4-(4-aminephenoxy)phenyl]propane,
1.1.1,3.3.3-hexachloro-2,2-bis[3,5-dimethyl-4-(4-aminophenoxy)phenyl]propane, 3,3-bis[3,5-dimethyl-
4-(4-ami/phenoxy)phenyl]pentane, 1
,1-bis[3,5-dimethyl-4-(4-aminoneenoxy)phenyl]propane, 1,1°1, 3.3.3
-hexafluoro-2,2-bis[3,5-dibromo-
4(4-aminophenoxy)phenyl]propane, 1
．． 1.1.3.3.3-hexachloro-λ2-bis(3
,5-dibromo-4-(4-aminophenoxy)phenyl]propane, 3,3-bis(3,5-dibromo-4-
(4-aminophenoxy)phenyl]pentane, ■, 1
-bis[3,5-dibromo-4-(4-aminophenoxy)phenyl]furopane.

2.2-bis[4-(4-aminophenoxy)phenylcobutane, 2,2-bis[3-methyl-4=(4-aminophenoxy)phenylcobutane, 2+2-bis[3,
5-dimethyl-4-(4-aminophenoxy)phenyl]phthane, 2,2-bis[3,5-dibromo-4-(4
-aminoneenoxy)phenylcobutane, 1.1.
1.3.3.3-hexafluoro-2,2-bis[3-
Examples include methyl-4-(4-aminophenoxy)phenyl]propane. In these houses, id, 2.2-bis[
4-(4-aminophenoxy)phenyl]propane is representative. if.

If necessary, a mixture of the above diamines can be used. I can do that.

Furthermore, in the present invention, known aromatic diamines such as 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, metaphenylenediamine, 4,4'-di(
4-Aminophenoxy) phenyl sulfone.

At least one of paraphenylenediamine, 4,4'-di(3-aminophenoxy)phenylsulfone, and 3,3'-diaminodiphenylsulfone can be used in combination. The ratio of these aromatic diamines to the total aromatic diamines is preferably 30 molti or less. If this ratio exceeds 307%, it is undesirable because it will adversely affect the solubility of the polycondensate.

As a compound represented by the general formula (■), for example, 1
m-aminephenol, p-aminephenol, 1-amino-5-naphthol, 1-amino-6-naphthol,
Examples include 1-amino-7-naphthol, 2-amino-5-naphthol, 4-(4'-aminophenyl)phenol, and aminophenols substituted with non-reactive groups such as alkyl and halogen. . General formula (
By copolymerizing the compound represented by IV),
Adhesion to the substrate (polyethylene terephthalate film) can be improved.

The aromatic dicarboxylic acid in the present invention includes:

For example, terephthalic acid, inphthalic acid, 4,4'-diphenyldicarboxylic acid, 3,4'-diphenyldicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene/dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid. and 3,4'-diphenyl ether dicarboxylic acid, among which terephthalic acid and isophthalic acid are commonly produced and can be preferably used. In particular, a mixture of terephthalic acid and isophthalic acid is desirable from the viewpoint of solubility of the resulting condensation polymer. In the present invention, the reactive derivative of aromatic dicarboxylic acid means dichloride, dichloride L, diester, etc. of the aromatic dicarboxylic acid. Furthermore, as mentioned above, when using a mixture of terephthalic acid and isophthalic acid, the blending ratio of isophthalic acid having a carboxyl group at the meta position of the benzene nucleus and terephthalic acid having a carboxyl group at the para position of the benzene nucleus is , the former is 20 to 80φ, while the latter is preferably within the range of 80 to 20q6, especially from the viewpoint of solubility.

As a solvent for the alignment control film, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-
Solvents such as methyl-2-pyrrolidone and cyclohexanone alone or in combination thereof, and further.

A mixture of the above aromatic polyether ester amide condensation polymers within a soluble range can be used. For example, than using the above solvents alone.

A mixed solvent containing appropriate amounts of cellosolves, toluene, xylene, etc. may yield a better film.

In addition to the above, there are no particular limitations as long as the aromatic polyether ester amide polymer can be dissolved therein.

Furthermore, in the present invention, in order to improve film formability, etc.
Other polymers may also be present.

Next, the present invention will be explained with reference to Examples, but the present invention is not limited to these in any way.

The orientation of the liquid crystal display element was evaluated based on the angle between the long axis direction of the liquid crystal molecules and the surface of the substrate, that is, the tilt angle between the substrate and the long axis of the liquid crystal molecules (tilt angle θ). For good orientation, a tilt angle of 1.5 to 3.0 is desirable, whereby the absolute value of the contrast ratio can be increased. [Tilt angles and their measurement methods can be found in the Journal of Applied Physics.
d Physics) Volume 19 (1980), A
10, pages 2013-4.

Example 1 A stirring rod, a thermometer, and a dropping funnel were set in a 7 volume flask, and 17,29% of NaOH was dissolved in 80 parts of water and placed in the flask. Next, 2,2-bis(4
-(4-Abanophenoxy)phenyl]propane44.
39- and m-aminone enol 7.91- were dissolved in cyclohexanone 3409- and injected into the above flask, -
Cooled to 2°C. On the other hand, dissolve 18.2 LiF of metal dichloride and 18.27 LiF of inphthalic acid dichloride in 24 oz of cyclohexanone, and inject this acid chloride solution into the flask from the dropping funnel. The reaction was allowed to take place for 3 hours. The reaction solution was poured into methanol to isolate the polymer.

After drying, this was dissolved in dimethylformamide again, and this was poured into methanol to obtain 2 pt of aromatic polyether ester amide condensation polymer (hereinafter abbreviated as polymer).
I had sex. Reduced viscosity (η51./.) of this polymer (0.2% by weight solution in dimethylformamide, measured at 30'C,
) was 1.0.

A 3.5% by weight solution of this polymer in N-methylpyrrolidone-butyl cellosolve acetate (mixing ratio 4:6) was applied onto a polyethylene terephthalate film having a transparent conductive film that had been thoroughly washed, using a spinner at 2000 rpm.
After uniformly coating the film at 120° C., the solvent was evaporated by drying at 120° C. for 10 minutes to form an orientation control film with a thickness of 1050 Å. This film was rubbed in a certain direction with felt to produce a substrate film having an orientation control film.

The alignment control films of the two films produced in this manner were placed facing each other, and these films were adhered with a sealing agent made of a polyester adhesive to produce a liquid crystal display element. The sealant was then cured at 120° C. for 5 minutes. between the alignment control films of this element.

Phenylcyclohexane liquid crystal (manufactured by Merck & Co.).

ZLI-1132) was placed and the alignment of the liquid crystal was examined between two orthogonal polarizing plates, and the alignment was found to be good. (
Tilt angle: 2 to 3 degrees) Example 2 A polymer was prepared using the same apparatus and method as in Example 1, except that raw materials having the following composition were used.

Using a 3.5 weight solution of this polymer in SN-methylpyrrolidone-butyl cellosolve acetate (mixing ratio 4:6),
A liquid crystal element was prepared by forming an alignment control film on the same film substrate as in Example 1, and the alignment of the liquid crystal was examined, which showed good alignment.

(Tilt angle: 2.4 degrees) Example 3 A polymer was prepared using the same apparatus and method as in Example 1, except that raw materials having the following composition were used.

C polymer 0 reduced viscosity (″·η) 1″·2f, IQ.

3.5% by weight of this polymer
A liquid crystal display element was prepared by forming a self-orientation control film on the same film substrate as in Example 1 using a butyl cellosolve acetate (mixing ratio 4:6) solution. It showed longevity orientation.

(Te, Rut angle: 2.3 degrees) Comparative Example A polymer was prepared using the same apparatus and method as in Example 1, except that raw materials having the following composition were used.

Using a 3.5% by weight N-methylpyrrolidone-butyl cellosolve acetate (mixing ratio 4:6) solution of this polymer,
A liquid crystal display element was prepared by forming an alignment control film on the same film substrate as in Example 1, and the alignment of the liquid crystal was examined.
It showed good orientation.

(Tilt angle: 24 degrees) Next, the adhesiveness with the polyethylene terephthalate film was evaluated by the following method. That is, the faces obtained in Examples and Comparative Examples were applied to a polyethylene terephthalate film using a spinner (200 Orpm - 30 sec).
) L, after drying at 1200C-1hr.

The film was repeatedly folded, liquid crystal was encapsulated in the same manner as described in Example 1, and the tilt angle was measured. The results are shown in Table 1.

Cloth 1 Measurement Results The liquid crystal display element of the present invention can be manufactured by using a specific aromatic polyether ester amide polymer as an alignment control film material. is a low temperature that does not cause thermal deformation (100~
Applying an orientation control film, that is, a film of a specific aromatic polyether ester amide polymer, which can be processed at (120°C),
2) These thermoplastic resins are insoluble or poorly soluble in water and liquid crystals, and only dissolve in specific solvents.
or.

(3) Since the film is completed by simply evaporating the solvent, an oriented film can be obtained at low temperatures and in a short time. Thereby, it is possible to provide a lightweight and thin liquid crystal display element.

Also, in the case of a glass substrate, it is possible to easily obtain a liquid crystal display element that is cheaper than the conventional method.

Furthermore, the alignment control film of the present invention has excellent adhesion to the substrate.

Note that the device of the present invention can also provide color display by arranging a guest-host type liquid crystal.

Furthermore, the durability of the liquid crystal display element of the present invention is practical.

There are no particular problems.

Agent Patent Attorney Kunihiko Wakabayashi 106-

Claims (1)

[Claims] 1. The alignment control film of the liquid crystal display element has the general formula (1) [However, in the general formulas (I) and (It), RIIR2
1R3 and R4 represent hydrogen, a lower alkyl group, a lower alkoxy group, chlorine or bromine, and they may be the same or different from each other, and R5 and R6 represent hydrogen, a methyl group, an ethyl group, a propyl group + 'J indicates a fluoromethyl group or a trichloromethyl group. They may be the same or different from each other.
r and Ar' represent p-phenylene group 1m-phenylene group, diphenylene group, naphthylene group or OCHs 11 C-, -8-+ C, CH2-, and this C
H3 They may be the same or different from each other, and have a repeating unit represented by A liquid crystal display element containing an aromatic polyether ester amide polymer.