JPH0463830A - Main-chain liquid crystalline copolymer, polymer liquid crystal composition containing same, and polymer liquid crystal element prepared from them - Google Patents

Abstract

PURPOSE:To prepare the title copolymer which facilitates the production of a liq. crystal element having a large area and has improved response characteristics by incorporating a specific structure contg. a chlorine group as a spacer and a three-ring structure as a mesogen into the copolymer. CONSTITUTION:For instance, a dicarboxylic acid dichloride and a diol having a chlorine group are allowed to undergo dehydrochlorination in an aprotic solvent at 50-300 deg.C to give the title copolymer which has a number-average mol.wt. of 2000-1000000, a structure of the formula contg. a chlorine group (wherein a and b are each 0-20) as a flexible spacer, and a three-ring structure wherein three rings selected from the group consisting of optionally substd. phenyl, heteroarom., and alicyclic rings are linked by a single bond, -O-, -COO-, -OCO-, -CONR'-, -NR'- (wherein R' is alkyl, etc.), -N=N-, -CidenticalC-, -CH=CH-, -(CH2)n-, -CO-, etc., as a mesogen.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to novel main chain type polymeric liquid crystal compounds having a chlorine group in a flexible spacer portion and having a three-ring structure as a mesogen, and their main chain types. The present invention relates to polymer liquid crystal compositions containing polymer liquid crystal compounds and polymer liquid crystal elements using these main chain type polymer liquid crystal compounds or polymer liquid crystal compositions.

The main chain polymer liquid crystal compound and polymer liquid crystal composition of the present invention can be used as optoelectronic materials typified by displays and memories, optical equipment materials, and the like.

[Prior Art] As a conventional liquid crystal element, for example, M-Shut (M,
5chadt) and Double Helfrich (W.

“Applied Physics Letters” by He1frich
Vol. 18, No. 4 (February 15, 1971), pp. 127-128.
Twisted Nematic Liquid Crystal” (
”Voltage Dependent 0ptica
l Activity of a Twisted Ne
Twisted nematic (twisted n
(ematic) devices using liquid crystals are known. However, this liquid crystal has a problem in that crosstalk occurs during time-division driving using a matrix electrode structure with high pixel density, so the number of pixels is limited.

Furthermore, its use as a display has been limited due to its slow electric field response and poor viewing angle characteristics. Further, there are problems in that the process of forming a thin film transistor in each pixel is extremely complicated, and it is difficult to create a large-area display element.

Clark (C1
ark) and Lagerwall. (JP-A-56-107216, U.S. Patent No. 4,367,924, etc.) This bistable liquid crystal is generally composed of a chiral smectic C phase (Sm''C) or H phase (Sm'H). Dielectric liquid crystal is used.

This ferroelectric liquid crystal has a very fast response speed because it is composed of spontaneous polarization, and can also exhibit a bistable state with memory properties. Furthermore, since it has excellent viewing angle characteristics, it is thought to be suitable as a material for large-capacity, large-area displays. However, when actually forming a liquid crystal cell, it is difficult to monodomain over a wide area, and there are technical problems in producing a large screen display element.

Furthermore, examples are known in which polymer liquid crystals are used as memory media.

For example, V, 5hibaev, Nis Kostromin, N, Plate, Nis Ivanov, S.
, Iva ov), Vestrov (V, Vestr.
ov), Ai Yakovlev (1, Yakovlev)
Written by “Polymer Communications”
"Thermotropic Liquid Crystalline Volimers, 14"("Ther.merCommunications") Volume 24, pp. 364-365.
mo-tropic Liquid Crystal
ine Polymer's, 14″).

However, when recording and preservation is performed using a glass transition point as a memory medium using a polymer liquid crystal, conventional polymer liquid crystal compounds have not had a sufficiently high glass transition point. In addition, there is also the problem of slow response speed due to polymerization, so it has not been put into practical use.

Also, JP-A-63-72784, JP-A-63-9
Although side chain type ferroelectric polymer liquid crystals are disclosed in JP-A No. 9204, JP-A No. 63-161005, etc.,
These side-chain polymer liquid crystals generally have the disadvantage that uniform alignment cannot be achieved by stretching, which is the easiest alignment method.

On the other hand, Watanabe et al.
Polymer Prepins, Japan)
Volume 38, No. 8, pp. 2371-2373 (198
9) reported a main chain type ferroelectric polymer liquid crystal using a hydrocarbon chiral diol. However, since a hydrocarbon-based chiral diol is used as the chiral group, the spontaneous polarization is small and the response speed cannot be said to be sufficiently fast.

[Problems to be Solved by the Invention] The present invention has been made to improve the drawbacks of the prior art, and its purpose is to provide large-area materials for optoelectronic materials, optical equipment materials, etc. A novel main chain type polymeric liquid crystal compound having a chlorine group in a flexible spacer part and having a three-ring structure as a mesogen, which has advantages such as easy operation and good response characteristics, and these compounds. It is an object of the present invention to provide a polymer liquid crystal element containing a polymer liquid crystal composition and a compound 1 composition thereof.

[Means for Solving the Problems] As a result of intensive studies in view of the above-mentioned prior art, the present inventors have developed a novel main body that has a chlorine group in the flexible spacer portion and has a three-ring structure as a mesogen. We have discovered a chain type polymeric liquid crystal compound and a polymeric liquid crystal composition containing the same, and the main chain type polymeric liquid crystal compound and polymeric liquid crystal composition have good response characteristics and take advantage of the characteristics of the polymer. The inventors have discovered that it is possible to easily realize a large-area liquid crystal element, and have completed the present invention.

That is, the first invention of the present invention is a main chain polymer liquid crystal compound having a structure represented by the following general formula [I] as a flexible spacer and having a three-ring structure as a mesogen.

General formula [I] P -0-(CH2), -CH-(CH2)b-0- (wherein a and b represent the same or different integers of 0 to 2o.

) Furthermore, the second invention of the present invention provides at least one main chain polymeric liquid crystal compound having a structure represented by the general formula [E] as a flexible spacer and having a three-ring structure as a mesogen. This is a polymer liquid crystal composition characterized by containing at least one compound among a polymer, a polymer liquid crystal, a low molecule, and a low molecular liquid crystal.

Furthermore, the third invention of the present invention provides at least one type of main chain polymeric liquid crystal compound having the structure represented by the general formula [I] as a flexible spacer and having a three-ring structure as a mesogen, or A polymer liquid crystal element using a polymer liquid crystal composition containing at least one main chain type polymer liquid crystal compound and at least one compound among polymers, polymer liquid crystals, low molecules, and low molecular liquid crystals. be.

The present invention will be explained in detail below.

The main chain type polymer liquid crystal compound of the first invention of the present invention has a structure represented by the following general formula [I] as a flexible spacer, and has a three-ring structure as a mesogen. It is a compound.

General formula [I] -0-(CH2)ll+ CH-(cl-1a)b-
o-In the general formula [I], a and b represent the same or different integers of 0 to 20, preferably 1 to 10.

Further, the main chain type polymeric liquid crystal compound of the present invention has the above-mentioned -1 [
The mesogen part has a three-ring structure in contrast to the flexible spacer part of [I]. What is the structure of the three rings?
Three of the optionally substituted benzene rings, heteroaromatic rings, and aliphatic rings are single bonds, -0-, -Coo
-, -0CO-, -CONR'--NR'- (R' represents an alkyl group, etc.), -N=N, -CEC, -C
It means a structure in which H=CH-, icH, )n-, -Co-, etc. are bonded. Specifically, for example, BeJco□
HA) co, stand.

()co　,()oco(t.

()o　co()cO2 units.

(To OC saliva) (Sawa.

(TocO, (To◎- (■ Straddle No. 2 oco (H).

(Meirisawa Cog Association.

(To N = 吋) (Sawa () (Huch CH=C bet.

(FcObe) River
-, -0CO-, a single bond or -〇-. ) Specific examples of the main chain type polymeric liquid crystal compound of the present invention include those having the following structures.

stomach.

(The methine carbon atom substituted with chlorine may or may not be optically active.) The number average molecular weight of the main chain polymeric liquid crystal compound of the present invention is preferably 2.000 to 1,000,000, and Preferably, it is in the range of 3.000 to 500.000; if it is less than 2.000, the film properties of the polymeric liquid crystal compound may deteriorate and the formability as a coating film may be impaired; If it exceeds this, the response to the outer ring may deteriorate due to the increase in viscosity.

The main chain type polymeric liquid crystal compound of the present invention is characterized in that it has a chlorine group in the flexible spacer portion. Therefore, the main chain polymer liquid crystal compound of the present invention has stronger intermolecular forces due to the chlorine groups, and therefore has a much higher glass transition point than the main chain polymer liquid crystal compound made of hydrocarbon flexible spacers. There is. This is a huge advantage when considered as a memory medium. In other words, polymer liquid crystal compounds can semi-permanently preserve the liquid crystal state or liquid crystal orientation at temperatures below the glass transition point, so the higher the glass transition point, the better the heat resistance of the memory. This is because the usable range is significantly wider.

Furthermore, among the main chain polymeric liquid crystal compounds of the present invention, they are optically active in that they can express a cholesteric liquid crystal phase having functions such as having a selective reflection wavelength or a chiral smectic C phase having ferroelectricity. A main chain type polymeric liquid crystal compound is preferred.

When a main chain polymer liquid crystal compound is used as a ferroelectric liquid crystal having high-speed response, there are advantages in terms of film properties and orientation. On the other hand, the hydrocarbon-based chiral groups of conventionally used main-chain polymeric liquid crystal compounds have small spontaneous polarization (
However, the response speed was not sufficient. However, since the main chain polymeric liquid crystal compound of the present invention has a chlorine group in the chiral portion, it has the advantage of having large spontaneous polarization and extremely fast response speed.

As mentioned above, unless optically active is required, optically inactive may be sufficient, but in this case, the racemate, which is industrially inexpensive and easily available, can be used as a raw material, and This method is preferable because the main chain polymeric liquid crystal compound of the invention can be produced industrially advantageously.

Furthermore, mesogens having a three-ring structure are characteristically used in the present invention. Compared to compounds consisting of bicyclic mesogens, it is possible to set the Tg at a higher temperature and the liquid crystal temperature range is wider, making them excellent as memory media and the like.

In addition, since it is easier to develop smectic liquid crystal than a bicyclic type, it is easier to obtain a ferroelectric polymer liquid crystal compound or composition.

Next is a method for producing the main chain type polymeric liquid crystal compound of the present invention. Polyester, polyether, etc. can be manufactured by conventional methods, but in the case of polyester compounds, when the melt polymerization method is carried out, due to the high temperature conditions, a decomposition reaction occurs in the halogen part and polymerization does not proceed quickly. There is.

Therefore, the following method can be preferably used as a method for producing the polyester compound of the present invention.

That is, this is a method for producing a main chain type polymer liquid crystalline polyester compound by subjecting a dicarboxylic acid dichloride and a diol having a chlorine group to a dehydrochlorination reaction in a solution. Examples of the dicarboxylic acid dichloride that can be used include the following compounds.

cI! oc (tope) (tope) cioc+ocpe) (pregnancy C0C1) cpoc (H reward COCl2 CβOC is) (to(pregnancy cocI! cp oc+c=c hard cocp etc.

Furthermore, examples of diols include the following compounds.

(J' HO-+CH2÷r-CH-CH20Hp HO-(-CH,←CH-CH20H C! HO-+CH, ÷"CH-+CH2÷r-OHI HO+CHz+y-CH-CH20H I2 HO-+CH2÷nCH-+CH2+ ``The solvent used in the oH reaction may be any abrotic solvent, such as chloroform, benzene, toluene, DMF.
, DMSO, HMPA, tetrachloroethane, T
I(F), diphenyl ether, ethylene glycol dimethyl ether, etc. Also, to prevent dicarboxylic acid dichloride from being hydrolyzed by moisture in the solvent,
Preferably, water in the solvent should be removed as much as possible. For the same reason, the reaction is better in N, Ar, than in air.
It is preferable to carry out under an atmosphere such as He. Additionally, an amine such as pyridine may be added to the system to scavenge hydrogen chloride.

The reaction temperature was below the boiling point of the solvent used, and in order to control the decomposition of the diol having a chlorine group, the reaction temperature was 30°C.
The temperature is preferably 0°C or lower, preferably 250°C or lower, and more preferably 200°C or lower.

Further, in order to rapidly advance the polymerization reaction, the temperature is preferably 50°C or higher, preferably 100°C or higher.

This production method controls the decomposition of diols containing chlorine groups by lowering the reaction temperature and lowering the density of the reaction substrate by using solution reaction, and allows the polymerization reaction to proceed quickly, making it easy to produce polymers. can do.

Next, the second invention of the present invention provides at least one main chain type polymer liquid crystal compound of the first invention and a polymer, a polymer liquid crystal,
The present invention is a polymer liquid crystal composition characterized by containing at least one type of compound among low molecules and low molecular liquid crystals.

As the compound to be blended with the main chain polymer liquid crystal compound of the first invention, polymer liquid crystals and low molecular liquid crystals are particularly preferred.

Examples of polymeric liquid crystals to be blended include the following.

−←0 (CH2), 0-3- CH.

-0CI (2CH-CH2CH20+ copolymer copolymer H3 Methyl butyl cinnamate (DOBA)I! B.C.) R3 is a hydrogen atom.

Alkyl group or halogen atom shows.

Also, These copolymers may also be mentioned as examples.

Examples of low-molecular liquid crystals to be blended include those shown below (P-hexyloxybenzylidene-P'-amino-2-chlorobrovir cinname) (HOBACPC).

P-decyloxybenzylidene-P'-amino-2-methylbutyl-α-cyanocinnamate (DOBAMBCC
) Methylbutyl-cyanocinnamate (TDOBAMBCC:) Methylbutyl-α-chlorocinnamate (OOBAMBCC) P-cutyloxybenzylidene-P'-amino-2-
Methylbutyl-α-methylcinnamate 4-hexyloxyphenyl-4-(2″-methylbutyl)biphenyl-4′-carboxylate 4-(2″-methylbutyl)
Phenyl-4-(4″-methylhexyl)biphenyl-
4'-carboxylate 4-year-old ctyloxyphenyl-
4-(2″-Methylbutyl)biphenyl-4′-carboxylate 4-(2′-(propyloxy)propyl)oxyphenyl-4-(desyloxy)biphenyl-4
'-Carboxylate 4-hexyloxyphenyl-4
-(2″-Methylbutyl)biphenyl-4′-carpoxylate (4′-(4-hexyloxy)phenyloxycarbonyl)phenyl-p-(4″-methylhexyloxy)benzoate 72.4″ and 0W 11fjt; The amount of the main chain type polymeric liquid crystal compound of the first invention contained in the polymeric liquid crystal composition of the invention is usually 5 to 95% by weight.
, more preferably in the range of 10 to 90% by weight.

If it is less than 5% by weight, the effect on obtaining good response may be small, or the formability, strength, and film forming properties may be poor. Moreover, if it exceeds 95% by weight, the properties may not be significantly different from those of a single compound.

In addition, a dye, a light stabilizer, a plasticizer, a light absorber, etc. can be added to the main chain type polymeric liquid crystal compound and polymeric liquid crystal composition according to the present invention.

Next, the third invention of the present invention has a polymer liquid crystal composition containing the main chain type polymer liquid crystal compound of the first invention or at least one type of the main chain type polymer liquid crystal compound as a blend component. It is a polymer liquid crystal element.

In the polymer liquid crystal device of the present invention, the main chain type polymer liquid crystal compound or polymer liquid crystal composition of the present invention is coated on a substrate made of any material such as glass, plastic, or metal to form a film. IT is formed on the substrate.
A transparent electrode such as an O film or a patterned electrode can also be formed.

In addition, alignment treatment may be performed, and examples of alignment treatment methods include the following methods: (1) Horizontal alignment (the direction of the molecular axis of the polymeric liquid crystal compound or polymeric liquid crystal composition is horizontal to the substrate surface) ■Rubbing method By solution coating, vapor deposition, sputtering, etc., on the substrate, for example, silicon oxide, silicon dioxide, aluminum oxide, zirconia, magnesium fluoride, cerium oxide, cerium fluoride, silicon nitride, silicon. Inorganic insulating materials such as carbides and boron nitrides, polyvinyl alcohol, polyimide, polyamideimide, polyesterimide, polyparaxylerin, polyester, polycarbonate, polyvinyl acetal, polyvinyl chloride,
A film of organic filler material such as polyamide, polystyrene, cellulose resin, melamine resin, urea resin, or acrylic resin is formed, and then the surface is rubbed in one direction with velvet, cloth, or paper to control orientation. Forms a film.

(2) Oblique Vapor Deposition An orientation control film is formed by depositing an oxide or fluoride such as SiO or a metal such as Au or A4 and its oxide from an oblique angle on the substrate.

(2) Oblique etching method The organic or inorganic insulating film shown in (3) is etched by obliquely irradiating the film with an ion beam or oxygen plasma to form an orientation control film.

■Use of stretched polymer film Stretch a polymer film made of polyester or polyvinyl alcohol.

■Grating method Grooves are formed on the surface of the substrate using photolithography, stump bar, or injection. In this case, the polymer liquid crystal compound or polymer liquid crystal composition is oriented in the direction of the groove.

(2) Orienting a shearing polymeric liquid crystal compound or polymeric liquid crystal composition by applying shear stress at a temperature higher than the liquid crystal state.

■Stretching Orientation is performed by uniaxial or biaxial stretching. It may be co-stretched with a substrate such as polyester or polyvinyl alcohol.

(2) Vertical alignment (orienting the molecular axis direction of the polymeric liquid crystal compound or polymeric liquid crystal composition perpendicularly to the substrate surface) (2) Forming a vertical alignment film.

A vertically aligned layer of organic silane, lecithin, polytetrafluoroethylene, etc. is formed on the surface of the substrate.

(2) Oblique evaporation (1) Vertical alignment can be provided by appropriately selecting the evaporation angle while rotating the substrate using the oblique evaporation method described in ○. Further, after oblique vapor deposition, a vertical alignment agent shown in (2) may be applied.

After such alignment treatment, a switching element can be obtained by forming an upper substrate having electrodes, for example.

The polymer liquid crystal element thus obtained is used as a display element, a memory element, etc. Using a polymer liquid crystal element using a polymer liquid crystal compound or polymer liquid crystal composition having a chiral smectic phase made of ferroelectricity enables high-speed switching, and has good memory properties due to its bistability. It can be used as a good large area display element, memory element, etc. Furthermore, in order to achieve bistability, there is a method of reducing the film thickness to eliminate the helix, and specifically, it is preferable to reduce the film thickness to 10 μm or less.

[Function] The main chain type polymeric liquid crystal compound and polymeric liquid crystal composition of the present invention can easily be made into large-area displays and memories, have a chlorine group in the flexible spacer part, and have a three-ring structure as a mesogen. Because of this, it has a high glass transition point (and a wide liquid crystal temperature range) (which makes it excellent as a memory medium, etc.).Also, if it is chiral and develops a cholesteric phase, it can form a unique optical thin film with a selective reflection wavelength. If it has a chiral smectic phase and ferroelectricity, it will have a large spontaneous polarization due to the large dipole of the chlorine group, and the conventional main chain type polymeric liquid crystal compound 7 composition ( It is extremely useful because it has a better response characteristic compared to the previous one.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to the following examples.

Example 1 cpoc-C)-(■-1cOcf 0.70g and optically active 2-chloro-1,4-butanediol 0.25g
g, 1,1゜2.2-tetrachloroethane 15 mA'
The reaction was carried out by stirring at 150° C. for 20 hours while flowing N2 inside.

After the reaction was completed, the product was repeatedly reprecipitated with methanol to obtain 0.41 g of polymer (2).

Phase transition temperature of polymer ■ Number average molecular weight 4,700 Weight average molecular weight 7.800 Example 2 cpoc-C■-(■-e■-cocI2o, 70
g Toracemic form (7) 0.25 g of 2-chloro-1,4-butanediol was stirred in 1.1.2.2-tetrachloroethane lSmf at 150°C for 20 hours while flowing N2 to perform a reaction. . After the reaction was completed, the product was repeatedly reprecipitated with methanol to obtain 0.48 g of Polymer (1).

Phase transition temperature of polymer (■) Number average molecular weight: 2,900 Weight average molecular weight: 6,900 Example 3 Polymer (■) was dissolved in chloroform and applied onto a glass substrate to form a polyimide rubbing film, and heated at 200°C.
When a thin film (film thickness: 10 pm) was formed by vacuum drying for 30 hours, selective wavelength reflection was observed.

Example 4 The response speed of the polymer liquid crystal composition shown below to an electric field was investigated. The results are shown in Table 1.

The polymeric liquid crystal composition shown in Table 1 was applied to a glass substrate provided with a polyimide alignment film and an ITO transparent electrode by pressing, spin cording or casting to obtain a film thickness of 10%.
After forming the pm film, annealing is performed,
Furthermore, the IO in the Sc” phase is added to the liquid crystal cell with the upper electrode attached.
An electric field of V/pm was applied.

At this time, inversion of the molecules in response to the electric field was observed.

Note that the response speed was measured by observing the response of the electric field.

Table 1 A shows the following low molecular liquid crystals, and B shows the following polymer liquid crystals.

Low molecular liquid crystal A: Polymer liquid crystal B: * indicates an asymmetric carbon atom.

Number average molecular weight: 7.800 Weight average molecular weight: 11.100 [Effects of the invention] As explained above, according to the present invention, a novel main chain type polymer liquid crystal compound capable of a large area, the main chain type polymer A polymeric liquid crystal composition containing a liquid crystal compound can be obtained.

Furthermore, when the main chain polymer liquid crystal compound of the present invention is used in a polymer liquid crystal device, it has good memory properties (and the polymer liquid crystal device using the main chain polymer liquid crystal compound and the polymer liquid crystal composition has chiral smectic properties). The response characteristics are good in the phase.

Claims (10)

[Claims] (1) A main chain polymeric liquid crystal compound having a structure represented by the following general formula [I] as a flexible spacer and a three-ring structure as a mesogen. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, a and b represent the same or different integers from 0 to 20.) (2) A main chain polymeric liquid crystalline polyester compound having a structure represented by the following general formula [I] as a flexible spacer and a three-ring structure as a mesogen. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, a and b represent the same or different integers from 0 to 20.) (3) A main chain polymeric liquid crystal compound having a repeating unit represented by the following general formula [II]. General formula [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, a and b represent the same or different integers from 0 to 20. c and d each represent 0 or 1, and X is -CO
Represents O-, -OCO-, a single bond or -O-. ) (4) The main chain polymeric liquid crystal compound according to claim 3, which is optically active. (5) The main chain polymeric liquid crystal compound according to claim 3, which is optically inactive. (6) at least one main chain type polymeric liquid crystal compound according to any one of claims 1 to 5; a polymer; a polymeric liquid crystal;
A polymer liquid crystal composition containing at least one type of compound selected from low molecules and low molecular liquid crystals. (7) The polymer liquid crystal composition according to claim 6, characterized in that it contains a plurality of types of polymer liquid crystals. (8) Claim 6 characterized in that it contains a low-molecular liquid crystal.
The polymer liquid crystal composition described above. (9) A polymeric liquid crystal device characterized in that it uses at least one type of main chain type polymeric liquid crystal compound according to any one of claims 1 to 5. (10) A polymer liquid crystal device comprising at least one of the polymer liquid crystal compositions according to claim 6, 7, or 8.